X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/3b6606c73ff0723f80146f1befa4838d59d3f8cf..eaf1e20af0294d79a176d2ac3b35fd4143163051:/ssh.c diff --git a/ssh.c b/ssh.c index 69972e49..38eb2bbd 100644 --- a/ssh.c +++ b/ssh.c @@ -1,3 +1,7 @@ +/* + * SSH backend. + */ + #include #include #include @@ -130,21 +134,21 @@ static const char *const ssh2_disconnect_reasons[] = { NULL, - "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", - "SSH_DISCONNECT_PROTOCOL_ERROR", - "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", - "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", - "SSH_DISCONNECT_MAC_ERROR", - "SSH_DISCONNECT_COMPRESSION_ERROR", - "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", - "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", - "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", - "SSH_DISCONNECT_CONNECTION_LOST", - "SSH_DISCONNECT_BY_APPLICATION", - "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", - "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", - "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", - "SSH_DISCONNECT_ILLEGAL_USER_NAME", + "host not allowed to connect", + "protocol error", + "key exchange failed", + "host authentication failed", + "MAC error", + "compression error", + "service not available", + "protocol version not supported", + "host key not verifiable", + "connection lost", + "by application", + "too many connections", + "auth cancelled by user", + "no more auth methods available", + "illegal user name", }; #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ @@ -459,13 +463,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, #define OUR_V2_WINSIZE 16384 #define OUR_V2_MAXPKT 0x4000UL +/* Maximum length of passwords/passphrases (arbitrary) */ +#define SSH_MAX_PASSWORD_LEN 100 + const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; const static struct ssh_mac *macs[] = { - &ssh_sha1, &ssh_md5 + &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 }; const static struct ssh_mac *buggymacs[] = { - &ssh_sha1_buggy, &ssh_md5 + &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5 }; static void *ssh_comp_none_init(void) @@ -679,7 +686,8 @@ struct ssh_tag { const struct plug_function_table *fn; /* the above field _must_ be first in the structure */ - SHA_State exhash, exhashbase; + char *v_c, *v_s; + void *exhash; Socket s; @@ -704,7 +712,8 @@ struct ssh_tag { void *cs_comp_ctx, *sc_comp_ctx; const struct ssh_kex *kex; const struct ssh_signkey *hostkey; - unsigned char v2_session_id[20]; + unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN]; + int v2_session_id_len; void *kex_ctx; char *savedhost; @@ -721,6 +730,7 @@ struct ssh_tag { struct ssh_channel *mainchan; /* primary session channel */ int exitcode; int close_expected; + int clean_exit; tree234 *rportfwds, *portfwds; @@ -749,13 +759,6 @@ struct ssh_tag { int fallback_cmd; bufchain banner; /* accumulates banners during do_ssh2_authconn */ - /* - * Used for username and password input. - */ - char *userpass_input_buffer; - int userpass_input_buflen; - int userpass_input_bufpos; - int userpass_input_echo; int pkt_ctx; @@ -1043,27 +1046,28 @@ static int alloc_channel_id(Ssh ssh) return low + 1 + CHANNEL_NUMBER_OFFSET; } +static void c_write_stderr(int trusted, const char *buf, int len) +{ + int i; + for (i = 0; i < len; i++) + if (buf[i] != '\r' && (trusted || buf[i] & 0x60)) + fputc(buf[i], stderr); +} + static void c_write(Ssh ssh, const char *buf, int len) { - if ((flags & FLAG_STDERR)) { - int i; - for (i = 0; i < len; i++) - if (buf[i] != '\r') - fputc(buf[i], stderr); - return; - } - from_backend(ssh->frontend, 1, buf, len); + if (flags & FLAG_STDERR) + c_write_stderr(1, buf, len); + else + from_backend(ssh->frontend, 1, buf, len); } static void c_write_untrusted(Ssh ssh, const char *buf, int len) { - int i; - for (i = 0; i < len; i++) { - if (buf[i] == '\n') - c_write(ssh, "\r\n", 2); - else if ((buf[i] & 0x60) || (buf[i] == '\r')) - c_write(ssh, buf + i, 1); - } + if (flags & FLAG_STDERR) + c_write_stderr(0, buf, len); + else + from_backend_untrusted(ssh->frontend, buf, len); } static void c_write_str(Ssh ssh, const char *buf) @@ -1266,7 +1270,8 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) * _Completely_ silly lengths should be stomped on before they * do us any more damage. */ - if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) { + if (st->len < 0 || st->len > 35000 || st->pad < 4 || + st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) { bombout(("Incoming packet was garbled on decryption")); ssh_free_packet(st->pktin); crStop(NULL); @@ -1559,21 +1564,21 @@ static int ssh_versioncmp(char *a, char *b) /* * Utility routines for putting an SSH-protocol `string' and - * `uint32' into a SHA state. + * `uint32' into a hash state. */ -static void sha_string(SHA_State * s, void *str, int len) +static void hash_string(const struct ssh_hash *h, void *s, void *str, int len) { unsigned char lenblk[4]; PUT_32BIT(lenblk, len); - SHA_Bytes(s, lenblk, 4); - SHA_Bytes(s, str, len); + h->bytes(s, lenblk, 4); + h->bytes(s, str, len); } -static void sha_uint32(SHA_State * s, unsigned i) +static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i) { unsigned char intblk[4]; PUT_32BIT(intblk, i); - SHA_Bytes(s, intblk, 4); + h->bytes(s, intblk, 4); } /* @@ -1583,7 +1588,7 @@ static void ssh_pkt_ensure(struct Packet *pkt, int length) { if (pkt->maxlen < length) { unsigned char *body = pkt->body; - int offset = body ? pkt->data - body : 0; + int offset = body ? body - pkt->data : 0; pkt->maxlen = length + 256; pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char); if (body) pkt->body = pkt->data + offset; @@ -1651,8 +1656,6 @@ static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) unsigned char *p; int i, n = (bignum_bitcount(b) + 7) / 8; p = snewn(n + 1, unsigned char); - if (!p) - fatalbox("out of memory"); p[0] = 0; for (i = 1; i <= n; i++) p[i] = bignum_byte(b, n - i); @@ -1695,10 +1698,10 @@ static struct Packet *ssh1_pkt_init(int pkt_type) static struct Packet *ssh2_pkt_init(int pkt_type) { struct Packet *pkt = ssh_new_packet(); - pkt->length = 5; + pkt->length = 5; /* space for packet length + padding length */ pkt->forcepad = 0; ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); - pkt->body = pkt->data + pkt->length; + pkt->body = pkt->data + pkt->length; /* after packet type */ return pkt; } @@ -1971,12 +1974,12 @@ void bndebug(char *string, Bignum b) } #endif -static void sha_mpint(SHA_State * s, Bignum b) +static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b) { unsigned char *p; int len; p = ssh2_mpint_fmt(b, &len); - sha_string(s, p, len); + hash_string(h, s, p, len); sfree(p); } @@ -2245,10 +2248,13 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) if (ssh->cfg.sshbug_rekey2 == FORCE_ON || (ssh->cfg.sshbug_rekey2 == AUTO && - (wc_match("OpenSSH_2.[0-4]*", imp) || + (wc_match("DigiSSH_2.0", imp) || + wc_match("OpenSSH_2.[0-4]*", imp) || wc_match("OpenSSH_2.5.[0-3]*", imp) || wc_match("Sun_SSH_1.0", imp) || - wc_match("Sun_SSH_1.0.1", imp)))) { + wc_match("Sun_SSH_1.0.1", imp) || + /* All versions <= 1.2.6 (they changed their format in 1.2.7) */ + wc_match("WeOnlyDo-*", imp)))) { /* * These versions have the SSH-2 rekey bug. */ @@ -2294,23 +2300,20 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crBegin(ssh->do_ssh_init_crstate); - /* Search for the string "SSH-" in the input. */ - s->i = 0; - while (1) { - static const int transS[] = { 1, 2, 2, 1 }; - static const int transH[] = { 0, 0, 3, 0 }; - static const int transminus[] = { 0, 0, 0, -1 }; - if (c == 'S') - s->i = transS[s->i]; - else if (c == 'H') - s->i = transH[s->i]; - else if (c == '-') - s->i = transminus[s->i]; - else - s->i = 0; - if (s->i < 0) - break; - crReturn(1); /* get another character */ + /* Search for a line beginning with the string "SSH-" in the input. */ + for (;;) { + if (c != 'S') goto no; + crReturn(1); + if (c != 'S') goto no; + crReturn(1); + if (c != 'H') goto no; + crReturn(1); + if (c != '-') goto no; + break; + no: + while (c != '\012') + crReturn(1); + crReturn(1); } s->vstrsize = 16; @@ -2384,15 +2387,19 @@ static int do_ssh_init(Ssh ssh, unsigned char c) ssh_fix_verstring(verstring); if (ssh->version == 2) { + size_t len; /* * Hash our version string and their version string. */ - SHA_Init(&ssh->exhashbase); - sha_string(&ssh->exhashbase, verstring, - strcspn(verstring, "\015\012")); - sha_string(&ssh->exhashbase, s->vstring, - strcspn(s->vstring, "\015\012")); - + len = strcspn(verstring, "\015\012"); + ssh->v_c = snewn(len + 1, char); + memcpy(ssh->v_c, verstring, len); + ssh->v_c[len] = 0; + len = strcspn(s->vstring, "\015\012"); + ssh->v_s = snewn(len + 1, char); + memcpy(ssh->v_s, s->vstring, len); + ssh->v_s[len] = 0; + /* * Initialise SSH-2 protocol. */ @@ -2497,24 +2504,29 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) * everything to s_rdpkt, and then pass the resulting packets * to the proper protocol handler. */ - if (datalen == 0) - crReturnV; - - /* - * Process queued data if there is any. - */ - ssh_process_queued_incoming_data(ssh); while (1) { - while (datalen > 0) { - if (ssh->frozen) + while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) { + if (ssh->frozen) { ssh_queue_incoming_data(ssh, &data, &datalen); - - ssh_process_incoming_data(ssh, &data, &datalen); - + /* This uses up all data and cannot cause anything interesting + * to happen; indeed, for anything to happen at all, we must + * return, so break out. */ + break; + } else if (bufchain_size(&ssh->queued_incoming_data) > 0) { + /* This uses up some or all data, and may freeze the + * session. */ + ssh_process_queued_incoming_data(ssh); + } else { + /* This uses up some or all data, and may freeze the + * session. */ + ssh_process_incoming_data(ssh, &data, &datalen); + } + /* FIXME this is probably EBW. */ if (ssh->state == SSH_STATE_CLOSED) return; } + /* We're out of data. Go and get some more. */ crReturnV; } crFinishV; @@ -2596,20 +2608,20 @@ static int ssh_closing(Plug plug, const char *error_msg, int error_code, Ssh ssh = (Ssh) plug; int need_notify = ssh_do_close(ssh, FALSE); - if (!error_msg && !ssh->close_expected) { - error_msg = "Server unexpectedly closed network connection"; + if (!error_msg) { + if (!ssh->close_expected) + error_msg = "Server unexpectedly closed network connection"; + else + error_msg = "Server closed network connection"; } if (need_notify) notify_remote_exit(ssh->frontend); - if (error_msg) { - /* A socket error has occurred. */ + if (error_msg) logevent(error_msg); + if (!ssh->close_expected || !ssh->clean_exit) connection_fatal(ssh->frontend, "%s", error_msg); - } else { - logevent("Server closed network connection"); - } return 0; } @@ -2656,8 +2668,6 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, const char *err; ssh->savedhost = snewn(1 + strlen(host), char); - if (!ssh->savedhost) - fatalbox("Out of memory"); strcpy(ssh->savedhost, host); if (port < 0) @@ -2742,78 +2752,6 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) } } -/* - * Username and password input, abstracted off into routines - * reusable in several places - even between SSH-1 and SSH-2. - */ - -/* Set up a username or password input loop on a given buffer. */ -static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo) -{ - ssh->userpass_input_buffer = buffer; - ssh->userpass_input_buflen = buflen; - ssh->userpass_input_bufpos = 0; - ssh->userpass_input_echo = echo; -} - -/* - * Process some terminal data in the course of username/password - * input. Returns >0 for success (line of input returned in - * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0 - * for inconclusive (keep waiting for more input please). - */ -static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen) -{ - char c; - - while (inlen--) { - switch (c = *in++) { - case 10: - case 13: - ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0; - ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0; - return +1; - break; - case 8: - case 127: - if (ssh->userpass_input_bufpos > 0) { - if (ssh->userpass_input_echo) - c_write_str(ssh, "\b \b"); - ssh->userpass_input_bufpos--; - } - break; - case 21: - case 27: - while (ssh->userpass_input_bufpos > 0) { - if (ssh->userpass_input_echo) - c_write_str(ssh, "\b \b"); - ssh->userpass_input_bufpos--; - } - break; - case 3: - case 4: - return -1; - break; - default: - /* - * This simplistic check for printability is disabled - * when we're doing password input, because some people - * have control characters in their passwords.o - */ - if ((!ssh->userpass_input_echo || - (c >= ' ' && c <= '~') || - ((unsigned char) c >= 160)) - && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) { - ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c; - if (ssh->userpass_input_echo) - c_write(ssh, &c, 1); - } - break; - } - } - return 0; -} - static void ssh_agent_callback(void *sshv, void *reply, int replylen) { Ssh ssh = (Ssh) sshv; @@ -2873,6 +2811,39 @@ static void ssh_agentf_callback(void *cv, void *reply, int replylen) } /* + * Client-initiated disconnection. Send a DISCONNECT if `wire_reason' + * non-NULL, otherwise just close the connection. `client_reason' == NULL + * => log `wire_reason'. + */ +static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, + int code, int clean_exit) +{ + char *error; + if (!client_reason) + client_reason = wire_reason; + if (client_reason) + error = dupprintf("Disconnected: %s", client_reason); + else + error = dupstr("Disconnected"); + if (wire_reason) { + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason, + PKT_END); + } else if (ssh->version == 2) { + struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(pktout, code); + ssh2_pkt_addstring(pktout, wire_reason); + ssh2_pkt_addstring(pktout, "en"); /* language tag */ + ssh2_pkt_send_noqueue(ssh, pktout); + } + } + ssh->close_expected = TRUE; + ssh->clean_exit = clean_exit; + ssh_closing((Plug)ssh, error, 0, 0); + sfree(error); +} + +/* * Handle the key exchange and user authentication phases. */ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, @@ -2893,9 +2864,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, char username[100]; void *publickey_blob; int publickey_bloblen; - char password[100]; - char prompt[200]; - int pos; + char *publickey_comment; + int publickey_encrypted; + prompts_t *cur_prompt; char c; int pwpkt_type; unsigned char request[5], *response, *p; @@ -2977,8 +2948,6 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); s->rsabuf = snewn(s->len, unsigned char); - if (!s->rsabuf) - fatalbox("Out of memory"); /* * Verify the host key. @@ -2990,8 +2959,6 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int len = rsastr_len(&hostkey); char fingerprint[100]; char *keystr = snewn(len, char); - if (!keystr) - fatalbox("Out of memory"); rsastr_fmt(keystr, &hostkey); rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); @@ -3015,8 +2982,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ssh_set_frozen(ssh, 0); if (s->dlgret == 0) { - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "User aborted at host key verification", + NULL, 0, TRUE); crStop(0); } } @@ -3096,8 +3063,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } ssh_set_frozen(ssh, 0); if (s->dlgret == 0) { - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); crStop(0); } } @@ -3161,35 +3128,33 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, logevent("Successfully started encryption"); - fflush(stdout); + fflush(stdout); /* FIXME eh? */ { if (!*ssh->cfg.username) { - if (ssh_get_line && !ssh_getline_pw_only) { - if (!ssh_get_line("login as: ", - s->username, sizeof(s->username), FALSE)) { - /* - * get_line failed to get a username. - * Terminate. - */ - logevent("No username provided. Abandoning session."); - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); - crStop(1); - } - } else { - int ret; /* need not be kept over crReturn */ - c_write_str(ssh, "login as: "); + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH login name"); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE, + lenof(s->username)); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { ssh->send_ok = 1; - - setup_userpass_input(ssh, s->username, sizeof(s->username), 1); - do { - crWaitUntil(!pktin); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get a username. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); + crStop(0); } + memcpy(s->username, s->cur_prompt->prompts[0]->result, + lenof(s->username)); + free_prompts(s->cur_prompt); } else { strncpy(s->username, ssh->cfg.username, sizeof(s->username)); s->username[sizeof(s->username)-1] = '\0'; @@ -3197,14 +3162,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END); { - char userlog[22 + sizeof(s->username)]; - sprintf(userlog, "Sent username \"%s\"", s->username); + char *userlog = dupprintf("Sent username \"%s\"", s->username); logevent(userlog); if (flags & FLAG_INTERACTIVE && (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { - strcat(userlog, "\r\n"); c_write_str(ssh, userlog); + c_write_str(ssh, "\r\n"); } + sfree(userlog); } } @@ -3217,18 +3182,51 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->tried_publickey = s->tried_agent = 0; } s->tis_auth_refused = s->ccard_auth_refused = 0; - /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */ + /* + * Load the public half of any configured keyfile for later use. + */ if (!filename_is_null(ssh->cfg.keyfile)) { - if (!rsakey_pubblob(&ssh->cfg.keyfile, - &s->publickey_blob, &s->publickey_bloblen, NULL)) + int keytype; + logeventf(ssh, "Reading private key file \"%.150s\"", + filename_to_str(&ssh->cfg.keyfile)); + keytype = key_type(&ssh->cfg.keyfile); + if (keytype == SSH_KEYTYPE_SSH1) { + const char *error; + if (rsakey_pubblob(&ssh->cfg.keyfile, + &s->publickey_blob, &s->publickey_bloblen, + &s->publickey_comment, &error)) { + s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile, + NULL); + } else { + char *msgbuf; + logeventf(ssh, "Unable to load private key (%s)", error); + msgbuf = dupprintf("Unable to load private key file " + "\"%.150s\" (%s)\r\n", + filename_to_str(&ssh->cfg.keyfile), + error); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } else { + char *msgbuf; + logeventf(ssh, "Unable to use this key file (%s)", + key_type_to_str(keytype)); + msgbuf = dupprintf("Unable to use key file \"%.150s\"" + " (%s)\r\n", + filename_to_str(&ssh->cfg.keyfile), + key_type_to_str(keytype)); + c_write_str(ssh, msgbuf); + sfree(msgbuf); s->publickey_blob = NULL; + } } else s->publickey_blob = NULL; while (pktin->type == SSH1_SMSG_FAILURE) { s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; - if (agent_exists() && !s->tried_agent) { + if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) { /* * Attempt RSA authentication using Pageant. */ @@ -3262,13 +3260,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->p += 4; logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { - logeventf(ssh, "Trying Pageant key #%d", s->keyi); - if (s->publickey_blob && - !memcmp(s->p, s->publickey_blob, - s->publickey_bloblen)) { - logevent("This key matches configured key file"); - s->tried_publickey = 1; - } + unsigned char *pkblob = s->p; s->p += 4; { int n, ok = FALSE; @@ -3301,6 +3293,17 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, break; } } + if (s->publickey_blob) { + if (!memcmp(pkblob, s->publickey_blob, + s->publickey_bloblen)) { + logeventf(ssh, "Pageant key #%d matches " + "configured key file", s->keyi); + s->tried_publickey = 1; + } else + /* Skip non-configured key */ + continue; + } + logeventf(ssh, "Trying Pageant key #%d", s->keyi); send_packet(ssh, SSH1_CMSG_AUTH_RSA, PKT_BIGNUM, s->key.modulus, PKT_END); crWaitUntil(pktin); @@ -3391,12 +3394,155 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, break; } sfree(s->response); + if (s->publickey_blob && !s->tried_publickey) + logevent("Configured key file not in Pageant"); } if (s->authed) break; } - if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey) - s->pwpkt_type = SSH1_CMSG_AUTH_RSA; + if (s->publickey_blob && !s->tried_publickey) { + /* + * Try public key authentication with the specified + * key file. + */ + int got_passphrase; /* need not be kept over crReturn */ + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Trying public key authentication.\r\n"); + logeventf(ssh, "Trying public key \"%s\"", + filename_to_str(&ssh->cfg.keyfile)); + s->tried_publickey = 1; + got_passphrase = FALSE; + while (!got_passphrase) { + /* + * Get a passphrase, if necessary. + */ + char *passphrase = NULL; /* only written after crReturn */ + const char *error; + if (!s->publickey_encrypted) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "No passphrase required.\r\n"); + passphrase = NULL; + } else { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = FALSE; + s->cur_prompt->name = dupstr("SSH key passphrase"); + add_prompt(s->cur_prompt, + dupprintf("Passphrase for key \"%.100s\": ", + s->publickey_comment), + FALSE, SSH_MAX_PASSWORD_LEN); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* Failed to get a passphrase. Terminate. */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + 0, TRUE); + crStop(0); + } + passphrase = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } + /* + * Try decrypting key with passphrase. + */ + ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase, + &error); + if (passphrase) { + memset(passphrase, 0, strlen(passphrase)); + sfree(passphrase); + } + if (ret == 1) { + /* Correct passphrase. */ + got_passphrase = TRUE; + } else if (ret == 0) { + c_write_str(ssh, "Couldn't load private key from "); + c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile)); + c_write_str(ssh, " ("); + c_write_str(ssh, error); + c_write_str(ssh, ").\r\n"); + got_passphrase = FALSE; + break; /* go and try something else */ + } else if (ret == -1) { + c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */ + got_passphrase = FALSE; + /* and try again */ + } else { + assert(0 && "unexpected return from loadrsakey()"); + } + } + + if (got_passphrase) { + + /* + * Send a public key attempt. + */ + send_packet(ssh, SSH1_CMSG_AUTH_RSA, + PKT_BIGNUM, s->key.modulus, PKT_END); + + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused our public key.\r\n"); + continue; /* go and try something else */ + } + if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + bombout(("Bizarre response to offer of public key")); + crStop(0); + } + + { + int i; + unsigned char buffer[32]; + Bignum challenge, response; + + if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) { + bombout(("Server's RSA challenge was badly formatted")); + crStop(0); + } + response = rsadecrypt(challenge, &s->key); + freebn(s->key.private_exponent);/* burn the evidence */ + + for (i = 0; i < 32; i++) { + buffer[i] = bignum_byte(response, 31 - i); + } + + MD5Init(&md5c); + MD5Update(&md5c, buffer, 32); + MD5Update(&md5c, s->session_id, 16); + MD5Final(buffer, &md5c); + + send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, buffer, 16, PKT_END); + + freebn(challenge); + freebn(response); + } + + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Failed to authenticate with" + " our public key.\r\n"); + continue; /* go and try something else */ + } else if (pktin->type != SSH1_SMSG_SUCCESS) { + bombout(("Bizarre response to RSA authentication response")); + crStop(0); + } + + break; /* we're through! */ + } + + } + + /* + * Otherwise, try various forms of password-like authentication. + */ + s->cur_prompt = new_prompts(ssh->frontend); if (ssh->cfg.try_tis_auth && (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) && @@ -3414,23 +3560,31 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } else { char *challenge; int challengelen; + char *instr_suf, *prompt; ssh_pkt_getstring(pktin, &challenge, &challengelen); if (!challenge) { bombout(("TIS challenge packet was badly formed")); crStop(0); } - c_write_str(ssh, "Using TIS authentication.\r\n"); logevent("Received TIS challenge"); - if (challengelen > sizeof(s->prompt) - 1) - challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ - memcpy(s->prompt, challenge, challengelen); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH TIS authentication"); /* Prompt heuristic comes from OpenSSH */ - strncpy(s->prompt + challengelen, - memchr(s->prompt, '\n', challengelen) ? - "": "\r\nResponse: ", - (sizeof s->prompt) - challengelen); - s->prompt[(sizeof s->prompt) - 1] = '\0'; + if (memchr(challenge, '\n', challengelen)) { + instr_suf = dupstr(""); + prompt = dupprintf("%.*s", challengelen, challenge); + } else { + instr_suf = dupprintf("%.*s", challengelen, challenge); + prompt = dupstr("Response: "); + } + s->cur_prompt->instruction = + dupprintf("Using TIS authentication.%s%s", + (*instr_suf) ? "\n" : "", + instr_suf); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN); + sfree(instr_suf); } } if (ssh->cfg.try_tis_auth && @@ -3448,53 +3602,40 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } else { char *challenge; int challengelen; + char *instr_suf, *prompt; ssh_pkt_getstring(pktin, &challenge, &challengelen); if (!challenge) { bombout(("CryptoCard challenge packet was badly formed")); crStop(0); } - c_write_str(ssh, "Using CryptoCard authentication.\r\n"); logevent("Received CryptoCard challenge"); - if (challengelen > sizeof(s->prompt) - 1) - challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ - memcpy(s->prompt, challenge, challengelen); - strncpy(s->prompt + challengelen, - memchr(s->prompt, '\n', challengelen) ? - "" : "\r\nResponse: ", - sizeof(s->prompt) - challengelen); - s->prompt[sizeof(s->prompt) - 1] = '\0'; + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH CryptoCard authentication"); + s->cur_prompt->name_reqd = FALSE; + /* Prompt heuristic comes from OpenSSH */ + if (memchr(challenge, '\n', challengelen)) { + instr_suf = dupstr(""); + prompt = dupprintf("%.*s", challengelen, challenge); + } else { + instr_suf = dupprintf("%.*s", challengelen, challenge); + prompt = dupstr("Response: "); + } + s->cur_prompt->instruction = + dupprintf("Using CryptoCard authentication.%s%s", + (*instr_suf) ? "\n" : "", + instr_suf); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN); + sfree(instr_suf); } } if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { - sprintf(s->prompt, "%.90s@%.90s's password: ", - s->username, ssh->savedhost); - } - if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { - char *comment = NULL; - int type; - if (flags & FLAG_VERBOSE) - c_write_str(ssh, "Trying public key authentication.\r\n"); - logeventf(ssh, "Trying public key \"%s\"", - filename_to_str(&ssh->cfg.keyfile)); - type = key_type(&ssh->cfg.keyfile); - if (type != SSH_KEYTYPE_SSH1) { - char *msg = dupprintf("Key is of wrong type (%s)", - key_type_to_str(type)); - logevent(msg); - c_write_str(ssh, msg); - c_write_str(ssh, "\r\n"); - sfree(msg); - s->tried_publickey = 1; - continue; - } - if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) { - if (flags & FLAG_VERBOSE) - c_write_str(ssh, "No passphrase required.\r\n"); - goto tryauth; - } - sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment); - sfree(comment); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH password"); + add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ", + s->username, ssh->savedhost), + FALSE, SSH_MAX_PASSWORD_LEN); } /* @@ -3502,251 +3643,155 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, * or CryptoCard exchange if we're doing TIS or CryptoCard * authentication. */ - if (ssh_get_line) { - if (!ssh_get_line(s->prompt, s->password, - sizeof(s->password), TRUE)) { + { + int ret; /* need not be kept over crReturn */ + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { /* - * get_line failed to get a password (for example + * Failed to get a password (for example * because one was supplied on the command line * which has already failed to work). Terminate. */ - send_packet(ssh, SSH1_MSG_DISCONNECT, - PKT_STR, "No more passwords available to try", - PKT_END); - logevent("Unable to authenticate"); - connection_fatal(ssh->frontend, "Unable to authenticate"); - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); - crStop(1); + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE); + crStop(0); } - } else { - /* Prompt may have come from server. We've munged it a bit, so - * we know it to be zero-terminated at least once. */ - int ret; /* need not be saved over crReturn */ - c_write_untrusted(ssh, s->prompt, strlen(s->prompt)); - s->pos = 0; - - setup_userpass_input(ssh, s->password, sizeof(s->password), 0); - do { - crWaitUntil(!pktin); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); } - tryauth: - if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { - /* - * Try public key authentication with the specified - * key file. - */ - s->tried_publickey = 1; - - { - const char *error = NULL; - int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password, - &error); - if (ret == 0) { - c_write_str(ssh, "Couldn't load private key from "); - c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile)); - c_write_str(ssh, " ("); - c_write_str(ssh, error); - c_write_str(ssh, ").\r\n"); - continue; /* go and try password */ - } - if (ret == -1) { - c_write_str(ssh, "Wrong passphrase.\r\n"); - s->tried_publickey = 0; - continue; /* try again */ - } - } - + if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { /* - * Send a public key attempt. + * Defence against traffic analysis: we send a + * whole bunch of packets containing strings of + * different lengths. One of these strings is the + * password, in a SSH1_CMSG_AUTH_PASSWORD packet. + * The others are all random data in + * SSH1_MSG_IGNORE packets. This way a passive + * listener can't tell which is the password, and + * hence can't deduce the password length. + * + * Anybody with a password length greater than 16 + * bytes is going to have enough entropy in their + * password that a listener won't find it _that_ + * much help to know how long it is. So what we'll + * do is: + * + * - if password length < 16, we send 15 packets + * containing string lengths 1 through 15 + * + * - otherwise, we let N be the nearest multiple + * of 8 below the password length, and send 8 + * packets containing string lengths N through + * N+7. This won't obscure the order of + * magnitude of the password length, but it will + * introduce a bit of extra uncertainty. + * + * A few servers (the old 1.2.18 through 1.2.22) + * can't deal with SSH1_MSG_IGNORE. For these + * servers, we need an alternative defence. We make + * use of the fact that the password is interpreted + * as a C string: so we can append a NUL, then some + * random data. + * + * One server (a Cisco one) can deal with neither + * SSH1_MSG_IGNORE _nor_ a padded password string. + * For this server we are left with no defences + * against password length sniffing. */ - send_packet(ssh, SSH1_CMSG_AUTH_RSA, - PKT_BIGNUM, s->key.modulus, PKT_END); - - crWaitUntil(pktin); - if (pktin->type == SSH1_SMSG_FAILURE) { - c_write_str(ssh, "Server refused our public key.\r\n"); - continue; /* go and try password */ - } - if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { - bombout(("Bizarre response to offer of public key")); - crStop(0); - } - - { - int i; - unsigned char buffer[32]; - Bignum challenge, response; - - if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) { - bombout(("Server's RSA challenge was badly formatted")); - crStop(0); - } - response = rsadecrypt(challenge, &s->key); - freebn(s->key.private_exponent);/* burn the evidence */ - - for (i = 0; i < 32; i++) { - buffer[i] = bignum_byte(response, 31 - i); - } - - MD5Init(&md5c); - MD5Update(&md5c, buffer, 32); - MD5Update(&md5c, s->session_id, 16); - MD5Final(buffer, &md5c); - - send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, - PKT_DATA, buffer, 16, PKT_END); - - freebn(challenge); - freebn(response); - } - - crWaitUntil(pktin); - if (pktin->type == SSH1_SMSG_FAILURE) { - if (flags & FLAG_VERBOSE) - c_write_str(ssh, "Failed to authenticate with" - " our public key.\r\n"); - continue; /* go and try password */ - } else if (pktin->type != SSH1_SMSG_SUCCESS) { - bombout(("Bizarre response to RSA authentication response")); - crStop(0); - } - - break; /* we're through! */ - } else { - if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { /* - * Defence against traffic analysis: we send a - * whole bunch of packets containing strings of - * different lengths. One of these strings is the - * password, in a SSH1_CMSG_AUTH_PASSWORD packet. - * The others are all random data in - * SSH1_MSG_IGNORE packets. This way a passive - * listener can't tell which is the password, and - * hence can't deduce the password length. - * - * Anybody with a password length greater than 16 - * bytes is going to have enough entropy in their - * password that a listener won't find it _that_ - * much help to know how long it is. So what we'll - * do is: - * - * - if password length < 16, we send 15 packets - * containing string lengths 1 through 15 - * - * - otherwise, we let N be the nearest multiple - * of 8 below the password length, and send 8 - * packets containing string lengths N through - * N+7. This won't obscure the order of - * magnitude of the password length, but it will - * introduce a bit of extra uncertainty. - * - * A few servers (the old 1.2.18 through 1.2.22) - * can't deal with SSH1_MSG_IGNORE. For these - * servers, we need an alternative defence. We make - * use of the fact that the password is interpreted - * as a C string: so we can append a NUL, then some - * random data. - * - * One server (a Cisco one) can deal with neither - * SSH1_MSG_IGNORE _nor_ a padded password string. - * For this server we are left with no defences - * against password length sniffing. + * The server can deal with SSH1_MSG_IGNORE, so + * we can use the primary defence. */ - if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { - /* - * The server can deal with SSH1_MSG_IGNORE, so - * we can use the primary defence. - */ - int bottom, top, pwlen, i; - char *randomstr; + int bottom, top, pwlen, i; + char *randomstr; - pwlen = strlen(s->password); - if (pwlen < 16) { - bottom = 0; /* zero length passwords are OK! :-) */ - top = 15; - } else { - bottom = pwlen & ~7; - top = bottom + 7; - } + pwlen = strlen(s->cur_prompt->prompts[0]->result); + if (pwlen < 16) { + bottom = 0; /* zero length passwords are OK! :-) */ + top = 15; + } else { + bottom = pwlen & ~7; + top = bottom + 7; + } - assert(pwlen >= bottom && pwlen <= top); + assert(pwlen >= bottom && pwlen <= top); - randomstr = snewn(top + 1, char); + randomstr = snewn(top + 1, char); - for (i = bottom; i <= top; i++) { - if (i == pwlen) { - defer_packet(ssh, s->pwpkt_type, - PKTT_PASSWORD, PKT_STR, s->password, - PKTT_OTHER, PKT_END); - } else { - for (j = 0; j < i; j++) { - do { - randomstr[j] = random_byte(); - } while (randomstr[j] == '\0'); - } - randomstr[i] = '\0'; - defer_packet(ssh, SSH1_MSG_IGNORE, - PKT_STR, randomstr, PKT_END); + for (i = bottom; i <= top; i++) { + if (i == pwlen) { + defer_packet(ssh, s->pwpkt_type, + PKTT_PASSWORD, PKT_STR, + s->cur_prompt->prompts[0]->result, + PKTT_OTHER, PKT_END); + } else { + for (j = 0; j < i; j++) { + do { + randomstr[j] = random_byte(); + } while (randomstr[j] == '\0'); } + randomstr[i] = '\0'; + defer_packet(ssh, SSH1_MSG_IGNORE, + PKT_STR, randomstr, PKT_END); } - logevent("Sending password with camouflage packets"); - ssh_pkt_defersend(ssh); - sfree(randomstr); - } - else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { - /* - * The server can't deal with SSH1_MSG_IGNORE - * but can deal with padded passwords, so we - * can use the secondary defence. - */ - char string[64]; - char *ss; - int len; - - len = strlen(s->password); - if (len < sizeof(string)) { - ss = string; - strcpy(string, s->password); - len++; /* cover the zero byte */ - while (len < sizeof(string)) { - string[len++] = (char) random_byte(); - } - } else { - ss = s->password; + } + logevent("Sending password with camouflage packets"); + ssh_pkt_defersend(ssh); + sfree(randomstr); + } + else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { + /* + * The server can't deal with SSH1_MSG_IGNORE + * but can deal with padded passwords, so we + * can use the secondary defence. + */ + char string[64]; + char *ss; + int len; + + len = strlen(s->cur_prompt->prompts[0]->result); + if (len < sizeof(string)) { + ss = string; + strcpy(string, s->cur_prompt->prompts[0]->result); + len++; /* cover the zero byte */ + while (len < sizeof(string)) { + string[len++] = (char) random_byte(); } - logevent("Sending length-padded password"); - send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, - PKT_INT, len, PKT_DATA, ss, len, - PKTT_OTHER, PKT_END); } else { - /* - * The server has _both_ - * BUG_CHOKES_ON_SSH1_IGNORE and - * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is - * therefore nothing we can do. - */ - int len; - len = strlen(s->password); - logevent("Sending unpadded password"); - send_packet(ssh, s->pwpkt_type, - PKTT_PASSWORD, PKT_INT, len, - PKT_DATA, s->password, len, - PKTT_OTHER, PKT_END); + ss = s->cur_prompt->prompts[0]->result; } - } else { + logevent("Sending length-padded password"); send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, - PKT_STR, s->password, PKTT_OTHER, PKT_END); + PKT_INT, len, PKT_DATA, ss, len, + PKTT_OTHER, PKT_END); + } else { + /* + * The server has _both_ + * BUG_CHOKES_ON_SSH1_IGNORE and + * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is + * therefore nothing we can do. + */ + int len; + len = strlen(s->cur_prompt->prompts[0]->result); + logevent("Sending unpadded password"); + send_packet(ssh, s->pwpkt_type, + PKTT_PASSWORD, PKT_INT, len, + PKT_DATA, s->cur_prompt->prompts[0]->result, len, + PKTT_OTHER, PKT_END); } + } else { + send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, + PKT_STR, s->cur_prompt->prompts[0]->result, + PKTT_OTHER, PKT_END); } logevent("Sent password"); - memset(s->password, 0, strlen(s->password)); + free_prompts(s->cur_prompt); crWaitUntil(pktin); if (pktin->type == SSH1_SMSG_FAILURE) { if (flags & FLAG_VERBOSE) @@ -3758,6 +3803,12 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } } + /* Clear up */ + if (s->publickey_blob) { + sfree(s->publickey_blob); + sfree(s->publickey_comment); + } + logevent("Authentication successful"); crFinish(1); @@ -4564,8 +4615,7 @@ static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) * encrypted packet, we close the session once * we've sent EXIT_CONFIRMATION. */ - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, NULL, NULL, 0, TRUE); } /* Helper function to deal with sending tty modes for REQUEST_PTY */ @@ -4918,27 +4968,30 @@ static int first_in_commasep_string(char *needle, char *haystack, int haylen) /* * SSH-2 key creation method. + * (Currently assumes 2 lots of any hash are sufficient to generate + * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.) */ -static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, - unsigned char *sessid, char chr, +#define SSH2_MKKEY_ITERS (2) +static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, unsigned char *keyspace) { - SHA_State s; - /* First 20 bytes. */ - SHA_Init(&s); + const struct ssh_hash *h = ssh->kex->hash; + void *s; + /* First hlen bytes. */ + s = h->init(); if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) - sha_mpint(&s, K); - SHA_Bytes(&s, H, 20); - SHA_Bytes(&s, &chr, 1); - SHA_Bytes(&s, sessid, 20); - SHA_Final(&s, keyspace); - /* Next 20 bytes. */ - SHA_Init(&s); + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + h->bytes(s, &chr, 1); + h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len); + h->final(s, keyspace); + /* Next hlen bytes. */ + s = h->init(); if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) - sha_mpint(&s, K); - SHA_Bytes(&s, H, 20); - SHA_Bytes(&s, keyspace, 20); - SHA_Final(&s, keyspace + 20); + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + h->bytes(s, keyspace, h->hlen); + h->final(s, keyspace + h->hlen); } /* @@ -4951,6 +5004,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, struct do_ssh2_transport_state { int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; Bignum p, g, e, f, K; + void *our_kexinit; + int our_kexinitlen; int kex_init_value, kex_reply_value; const struct ssh_mac **maclist; int nmacs; @@ -4963,9 +5018,9 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, char *hostkeydata, *sigdata, *keystr, *fingerprint; int hostkeylen, siglen; void *hkey; /* actual host key */ - unsigned char exchange_hash[20]; + unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN]; int n_preferred_kex; - const struct ssh_kex *preferred_kex[KEX_MAX]; + const struct ssh_kexes *preferred_kex[KEX_MAX]; int n_preferred_ciphers; const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; const struct ssh_compress *preferred_comp; @@ -5016,7 +5071,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, s->preferred_kex[s->n_preferred_kex++] = &ssh_diffiehellman_group1; break; - case CIPHER_WARN: + case KEX_WARN: /* Flag for later. Don't bother if it's the last in * the list. */ if (i < KEX_MAX - 1) { @@ -5088,12 +5143,14 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh2_pkt_addstring_start(s->pktout); commalist_started = 0; for (i = 0; i < s->n_preferred_kex; i++) { - const struct ssh_kex *k = s->preferred_kex[i]; + const struct ssh_kexes *k = s->preferred_kex[i]; if (!k) continue; /* warning flag */ - if (commalist_started) - ssh2_pkt_addstring_str(s->pktout, ","); - ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name); - commalist_started = 1; + for (j = 0; j < k->nkexes; j++) { + if (commalist_started) + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, k->list[j]->name); + commalist_started = 1; + } } /* List server host key algorithms. */ ssh2_pkt_addstring_start(s->pktout); @@ -5174,15 +5231,14 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh2_pkt_adduint32(s->pktout, 0); } - ssh->exhash = ssh->exhashbase; - sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5); + s->our_kexinitlen = s->pktout->length - 5; + s->our_kexinit = snewn(s->our_kexinitlen, unsigned char); + memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen); ssh2_pkt_send_noqueue(ssh, s->pktout); if (!pktin) crWaitUntil(pktin); - if (pktin->length > 5) - sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5); /* * Now examine the other side's KEXINIT to see what we're up @@ -5211,13 +5267,17 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, preferred = NULL; for (i = 0; i < s->n_preferred_kex; i++) { - const struct ssh_kex *k = s->preferred_kex[i]; + const struct ssh_kexes *k = s->preferred_kex[i]; if (!k) { s->warn_kex = TRUE; } else { - if (!preferred) preferred = k->name; - if (in_commasep_string(k->name, str, len)) - ssh->kex = k; + for (j = 0; j < k->nkexes; j++) { + if (!preferred) preferred = k->list[j]->name; + if (in_commasep_string(k->list[j]->name, str, len)) { + ssh->kex = k->list[j]; + break; + } + } } if (ssh->kex) break; @@ -5340,8 +5400,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } ssh_set_frozen(ssh, 0); if (s->dlgret == 0) { - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "User aborted at kex warning", NULL, + 0, TRUE); crStop(0); } } @@ -5365,8 +5425,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } ssh_set_frozen(ssh, 0); if (s->dlgret == 0) { - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); crStop(0); } } @@ -5390,12 +5450,22 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } ssh_set_frozen(ssh, 0); if (s->dlgret == 0) { - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); crStop(0); } } + ssh->exhash = ssh->kex->hash->init(); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); + hash_string(ssh->kex->hash, ssh->exhash, + s->our_kexinit, s->our_kexinitlen); + sfree(s->our_kexinit); + if (pktin->length > 5) + hash_string(ssh->kex->hash, ssh->exhash, + pktin->data + 5, pktin->length - 5); + if (s->ignorepkt) /* first_kex_packet_follows */ crWaitUntil(pktin); /* Ignore packet */ } @@ -5412,10 +5482,10 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, scbits = s->sccipher_tobe->keylen; s->nbits = (csbits > scbits ? csbits : scbits); } - /* The keys only have 160-bit entropy, since they're based on - * a SHA-1 hash. So cap the key size at 160 bits. */ - if (s->nbits > 160) - s->nbits = 160; + /* The keys only have hlen-bit entropy, since they're based on + * a hash. So cap the key size at hlen bits. */ + if (s->nbits > ssh->kex->hash->hlen * 8) + s->nbits = ssh->kex->hash->hlen * 8; /* * If we're doing Diffie-Hellman group exchange, start by @@ -5456,7 +5526,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh->kex->groupname); } - logevent("Doing Diffie-Hellman key exchange"); + logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s", + ssh->kex->hash->text_name); /* * Now generate and send e for Diffie-Hellman. */ @@ -5487,29 +5558,31 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * involve user interaction. */ set_busy_status(ssh->frontend, BUSY_NOT); - sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen); - if (ssh->kex == &ssh_diffiehellman_gex) { - sha_uint32(&ssh->exhash, s->pbits); - sha_mpint(&ssh->exhash, s->p); - sha_mpint(&ssh->exhash, s->g); + hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); + if (!ssh->kex->pdata) { + hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits); + hash_mpint(ssh->kex->hash, ssh->exhash, s->p); + hash_mpint(ssh->kex->hash, ssh->exhash, s->g); } - sha_mpint(&ssh->exhash, s->e); - sha_mpint(&ssh->exhash, s->f); - sha_mpint(&ssh->exhash, s->K); - SHA_Final(&ssh->exhash, s->exchange_hash); + hash_mpint(ssh->kex->hash, ssh->exhash, s->e); + hash_mpint(ssh->kex->hash, ssh->exhash, s->f); + hash_mpint(ssh->kex->hash, ssh->exhash, s->K); + assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash)); + ssh->kex->hash->final(ssh->exhash, s->exchange_hash); dh_cleanup(ssh->kex_ctx); ssh->kex_ctx = NULL; #if 0 debug(("Exchange hash is:\n")); - dmemdump(s->exchange_hash, 20); + dmemdump(s->exchange_hash, ssh->kex->hash->hlen); #endif s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); if (!s->hkey || !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, - (char *)s->exchange_hash, 20)) { + (char *)s->exchange_hash, + ssh->kex->hash->hlen)) { bombout(("Server's host key did not match the signature supplied")); crStop(0); } @@ -5539,8 +5612,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } ssh_set_frozen(ssh, 0); if (s->dlgret == 0) { - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "User aborted at host key verification", NULL, + 0, TRUE); crStop(0); } if (!s->got_session_id) { /* don't bother logging this in rekeys */ @@ -5557,8 +5630,11 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * authentication. */ if (!s->got_session_id) { + assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id)); memcpy(ssh->v2_session_id, s->exchange_hash, sizeof(s->exchange_hash)); + ssh->v2_session_id_len = ssh->kex->hash->hlen; + assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id)); s->got_session_id = TRUE; } @@ -5593,13 +5669,21 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * hash from the _first_ key exchange. */ { - unsigned char keyspace[40]; - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace); + unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; + assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); + assert((ssh->cscipher->keylen+7) / 8 <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); + assert(ssh->cscipher->blksize <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); + assert(ssh->csmac->len <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); + memset(keyspace, 0, sizeof(keyspace)); } logeventf(ssh, "Initialised %.200s client->server encryption", @@ -5651,13 +5735,21 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * hash from the _first_ key exchange. */ { - unsigned char keyspace[40]; - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace); + unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; + assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace); + assert((ssh->sccipher->keylen+7) / 8 <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace); + assert(ssh->sccipher->blksize <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); + assert(ssh->scmac->len <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); + memset(keyspace, 0, sizeof(keyspace)); } logeventf(ssh, "Initialised %.200s server->client encryption", ssh->sccipher->text_name); @@ -5672,7 +5764,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, */ freebn(s->f); freebn(s->K); - if (ssh->kex == &ssh_diffiehellman_gex) { + if (!ssh->kex->pdata) { freebn(s->g); freebn(s->p); } @@ -5706,7 +5798,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * it would only confuse the layer above. */ if (s->activated_authconn) { - crReturn(1); + crReturn(0); } s->activated_authconn = TRUE; @@ -6021,8 +6113,6 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) * not running in -N mode.) */ if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) { - logevent("All channels closed. Disconnecting"); -#if 0 /* * We used to send SSH_MSG_DISCONNECT here, * because I'd believed that _every_ conforming @@ -6034,14 +6124,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) * this is more polite than sending a * DISCONNECT. So now we don't. */ - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, "All open channels closed"); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); -#endif - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); } } @@ -6128,18 +6211,10 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) */ c = find234(ssh->channels, &localid, ssh_channelfind); if (!c) { - char buf[80]; - sprintf(buf, "Received channel request for nonexistent" - " channel %d", localid); - logevent(buf); - pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(pktout, buf); - ssh2_pkt_addstring(pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, pktout); - connection_fatal(ssh->frontend, "%s", buf); - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + char *buf = dupprintf("Received channel request for nonexistent" + " channel %d", localid); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); return; } @@ -6349,7 +6424,7 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) } } } else if (typelen == 22 && - !memcmp(type, "auth-agent@openssh.com", 3)) { + !memcmp(type, "auth-agent@openssh.com", 22)) { if (!ssh->agentfwd_enabled) error = "Agent forwarding is not enabled"; else { @@ -6431,11 +6506,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, { struct do_ssh2_authconn_state { enum { - AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, - AUTH_PASSWORD, - AUTH_KEYBOARD_INTERACTIVE - } method; - enum { AUTH_TYPE_NONE, AUTH_TYPE_PUBLICKEY, AUTH_TYPE_PUBLICKEY_OFFER_LOUD, @@ -6446,20 +6516,23 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } type; int done_service_req; int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; - int tried_pubkey_config, tried_agent; - int kbd_inter_running, kbd_inter_refused; + int tried_pubkey_config, done_agent; + int kbd_inter_refused; int we_are_in; - int num_prompts, curr_prompt, echo; + prompts_t *cur_prompt; + int num_prompts; char username[100]; + char *password; int got_username; - char pwprompt[512]; - char password[100]; void *publickey_blob; int publickey_bloblen; - unsigned char request[5], *response, *p; - int responselen; + int publickey_encrypted; + char *publickey_algorithm; + char *publickey_comment; + unsigned char agent_request[5], *agent_response, *agentp; + int agent_responselen; + unsigned char *pkblob_in_agent; int keyi, nkeys; - int authed; char *pkblob, *alg, *commentp; int pklen, alglen, commentlen; int siglen, retlen, len; @@ -6501,6 +6574,126 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } } + /* Arrange to be able to deal with any BANNERs that come in. + * (We do this now as packets may come in during the next bit.) */ + bufchain_init(&ssh->banner); + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = + ssh2_msg_userauth_banner; + + /* + * Misc one-time setup for authentication. + */ + s->publickey_blob = NULL; + if (!s->we_are_in) { + + /* + * Load the public half of any configured public key file + * for later use. + */ + if (!filename_is_null(ssh->cfg.keyfile)) { + int keytype; + logeventf(ssh, "Reading private key file \"%.150s\"", + filename_to_str(&ssh->cfg.keyfile)); + keytype = key_type(&ssh->cfg.keyfile); + if (keytype == SSH_KEYTYPE_SSH2) { + const char *error; + s->publickey_blob = + ssh2_userkey_loadpub(&ssh->cfg.keyfile, + &s->publickey_algorithm, + &s->publickey_bloblen, + &s->publickey_comment, &error); + if (s->publickey_blob) { + s->publickey_encrypted = + ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL); + } else { + char *msgbuf; + logeventf(ssh, "Unable to load private key (%s)", + error); + msgbuf = dupprintf("Unable to load private key file " + "\"%.150s\" (%s)\r\n", + filename_to_str(&ssh->cfg.keyfile), + error); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + } + } else { + char *msgbuf; + logeventf(ssh, "Unable to use this key file (%s)", + key_type_to_str(keytype)); + msgbuf = dupprintf("Unable to use key file \"%.150s\"" + " (%s)\r\n", + filename_to_str(&ssh->cfg.keyfile), + key_type_to_str(keytype)); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } + + /* + * Find out about any keys Pageant has (but if there's a + * public key configured, filter out all others). + */ + s->nkeys = 0; + s->agent_response = NULL; + s->pkblob_in_agent = NULL; + if (ssh->cfg.tryagent && agent_exists()) { + + void *r; + + logevent("Pageant is running. Requesting keys."); + + /* Request the keys held by the agent. */ + PUT_32BIT(s->agent_request, 1); + s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; + if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen, + ssh_agent_callback, ssh)) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for agent response")); + crStopV; + } + } while (pktin || inlen > 0); + r = ssh->agent_response; + s->agent_responselen = ssh->agent_response_len; + } + s->agent_response = (unsigned char *) r; + if (s->agent_response && s->agent_responselen >= 5 && + s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { + int keyi; + unsigned char *p; + p = s->agent_response + 5; + s->nkeys = GET_32BIT(p); + p += 4; + logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); + if (s->publickey_blob) { + /* See if configured key is in agent. */ + for (keyi = 0; keyi < s->nkeys; keyi++) { + s->pklen = GET_32BIT(p); + if (s->pklen == s->publickey_bloblen && + !memcmp(p+4, s->publickey_blob, + s->publickey_bloblen)) { + logeventf(ssh, "Pageant key #%d matches " + "configured key file", keyi); + s->keyi = keyi; + s->pkblob_in_agent = p; + break; + } + p += 4 + s->pklen; + p += GET_32BIT(p) + 4; /* comment */ + } + if (!s->pkblob_in_agent) { + logevent("Configured key file not in Pageant"); + s->nkeys = 0; + } + } + } + } + + } + /* * We repeat this whole loop, including the username prompt, * until we manage a successful authentication. If the user @@ -6527,9 +6720,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ s->username[0] = '\0'; s->got_username = FALSE; - bufchain_init(&ssh->banner); - ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = - ssh2_msg_userauth_banner; while (!s->we_are_in) { /* * Get a username. @@ -6541,32 +6731,31 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * it again. */ } else if (!*ssh->cfg.username) { - if (ssh_get_line && !ssh_getline_pw_only) { - if (!ssh_get_line("login as: ", - s->username, sizeof(s->username), FALSE)) { - /* - * get_line failed to get a username. - * Terminate. - */ - logevent("No username provided. Abandoning session."); - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; - } - } else { - int ret; /* need not be saved across crReturn */ - c_write_str(ssh, "login as: "); + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH login name"); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE, + lenof(s->username)); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { ssh->send_ok = 1; - setup_userpass_input(ssh, s->username, sizeof(s->username), 1); - do { - crWaitUntilV(!pktin); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; } - s->username[strcspn(s->username, "\n\r")] = '\0'; + if (!ret) { + /* + * get_userpass_input() failed to get a username. + * Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); + crStopV; + } + memcpy(s->username, s->cur_prompt->prompts[0]->result, + lenof(s->username)); + free_prompts(s->cur_prompt); } else { char *stuff; strncpy(s->username, ssh->cfg.username, sizeof(s->username)); @@ -6596,33 +6785,18 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->we_are_in = FALSE; s->tried_pubkey_config = FALSE; - s->tried_agent = FALSE; - s->kbd_inter_running = FALSE; s->kbd_inter_refused = FALSE; - /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */ - if (!filename_is_null(ssh->cfg.keyfile)) { - int keytype; - logeventf(ssh, "Reading private key file \"%.150s\"", - filename_to_str(&ssh->cfg.keyfile)); - keytype = key_type(&ssh->cfg.keyfile); - if (keytype == SSH_KEYTYPE_SSH2) { - s->publickey_blob = - ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL, - &s->publickey_bloblen, NULL); + + /* Reset agent request state. */ + s->done_agent = FALSE; + if (s->agent_response) { + if (s->pkblob_in_agent) { + s->agentp = s->pkblob_in_agent; } else { - char *msgbuf; - logeventf(ssh, "Unable to use this key file (%s)", - key_type_to_str(keytype)); - msgbuf = dupprintf("Unable to use key file \"%.150s\"" - " (%s)\r\n", - filename_to_str(&ssh->cfg.keyfile), - key_type_to_str(keytype)); - c_write_str(ssh, msgbuf); - sfree(msgbuf); - s->publickey_blob = NULL; + s->agentp = s->agent_response + 5 + 4; + s->keyi = 0; } - } else - s->publickey_blob = NULL; + } while (1) { /* @@ -6660,24 +6834,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, break; } - if (s->kbd_inter_running && - pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) { - /* - * This is either a further set-of-prompts packet - * in keyboard-interactive authentication, or it's - * the same one and we came back here with `gotit' - * set. In the former case, we must reset the - * curr_prompt variable. - */ - if (!s->gotit) - s->curr_prompt = 0; - } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { - /* FIXME: perhaps we should support this? */ - bombout(("PASSWD_CHANGEREQ not yet supported")); - crStopV; - } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) { - bombout(("Strange packet received during authentication: type %d", - pktin->type)); + if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) { + bombout(("Strange packet received during authentication: " + "type %d", pktin->type)); crStopV; } @@ -6692,7 +6851,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, char *methods; int methlen; ssh_pkt_getstring(pktin, &methods, &methlen); - s->kbd_inter_running = FALSE; if (!ssh2_pkt_getbool(pktin)) { /* * We have received an unequivocal Access @@ -6749,418 +6907,275 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, in_commasep_string("keyboard-interactive", methods, methlen); } - s->method = 0; ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - s->need_pw = FALSE; - /* - * Most password/passphrase prompts will be - * non-echoing, so we set this to 0 by default. - * Exception is that some keyboard-interactive prompts - * can be echoing, in which case we'll set this to 1. - */ - s->echo = 0; + if (s->can_pubkey && !s->done_agent && s->nkeys) { - if (!s->method && s->can_pubkey && - agent_exists() && !s->tried_agent) { /* - * Attempt public-key authentication using Pageant. + * Attempt public-key authentication using a key from Pageant. */ - void *r; - s->authed = FALSE; ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; - s->tried_agent = TRUE; + logeventf(ssh, "Trying Pageant key #%d", s->keyi); + + /* Unpack key from agent response */ + s->pklen = GET_32BIT(s->agentp); + s->agentp += 4; + s->pkblob = (char *)s->agentp; + s->agentp += s->pklen; + s->alglen = GET_32BIT(s->pkblob); + s->alg = s->pkblob + 4; + s->commentlen = GET_32BIT(s->agentp); + s->agentp += 4; + s->commentp = (char *)s->agentp; + s->agentp += s->commentlen; + /* s->agentp now points at next key, if any */ + + /* See if server will accept it */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, s->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET; - logevent("Pageant is running. Requesting keys."); + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { - /* Request the keys held by the agent. */ - PUT_32BIT(s->request, 1); - s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; - if (!agent_query(s->request, 5, &r, &s->responselen, - ssh_agent_callback, ssh)) { - do { - crReturnV; - if (pktin) { - bombout(("Unexpected data from server while" - " waiting for agent response")); - crStopV; - } - } while (pktin || inlen > 0); - r = ssh->agent_response; - s->responselen = ssh->agent_response_len; - } - s->response = (unsigned char *) r; - if (s->response && s->responselen >= 5 && - s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { - s->p = s->response + 5; - s->nkeys = GET_32BIT(s->p); - s->p += 4; - logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); - for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { - void *vret; + /* Offer of key refused. */ + s->gotit = TRUE; - logeventf(ssh, "Trying Pageant key #%d", s->keyi); - s->pklen = GET_32BIT(s->p); - s->p += 4; - if (s->publickey_blob && - s->pklen == s->publickey_bloblen && - !memcmp(s->p, s->publickey_blob, - s->publickey_bloblen)) { - logevent("This key matches configured key file"); - s->tried_pubkey_config = 1; - } - s->pkblob = (char *)s->p; - s->p += s->pklen; - s->alglen = GET_32BIT(s->pkblob); - s->alg = s->pkblob + 4; - s->commentlen = GET_32BIT(s->p); - s->p += 4; - s->commentp = (char *)s->p; - s->p += s->commentlen; - s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ - ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ - ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); - ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); - ssh2_pkt_send(ssh, s->pktout); - - crWaitUntilV(pktin); - if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { - logevent("Key refused"); - continue; - } + } else { + + void *vret; - if (flags & FLAG_VERBOSE) { - c_write_str(ssh, "Authenticating with " - "public key \""); - c_write(ssh, s->commentp, s->commentlen); - c_write_str(ssh, "\" from agent\r\n"); - } + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticating with " + "public key \""); + c_write(ssh, s->commentp, s->commentlen); + c_write_str(ssh, "\" from agent\r\n"); + } - /* - * Server is willing to accept the key. - * Construct a SIGN_REQUEST. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ - ssh2_pkt_addbool(s->pktout, TRUE); - ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); - ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); - - s->siglen = s->pktout->length - 5 + 4 + 20; - if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) - s->siglen -= 4; - s->len = 1; /* message type */ - s->len += 4 + s->pklen; /* key blob */ - s->len += 4 + s->siglen; /* data to sign */ - s->len += 4; /* flags */ - s->agentreq = snewn(4 + s->len, char); - PUT_32BIT(s->agentreq, s->len); - s->q = s->agentreq + 4; - *s->q++ = SSH2_AGENTC_SIGN_REQUEST; - PUT_32BIT(s->q, s->pklen); - s->q += 4; - memcpy(s->q, s->pkblob, s->pklen); - s->q += s->pklen; - PUT_32BIT(s->q, s->siglen); + /* + * Server is willing to accept the key. + * Construct a SIGN_REQUEST. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, s->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */ + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); + + /* Ask agent for signature. */ + s->siglen = s->pktout->length - 5 + 4 + + ssh->v2_session_id_len; + if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) + s->siglen -= 4; + s->len = 1; /* message type */ + s->len += 4 + s->pklen; /* key blob */ + s->len += 4 + s->siglen; /* data to sign */ + s->len += 4; /* flags */ + s->agentreq = snewn(4 + s->len, char); + PUT_32BIT(s->agentreq, s->len); + s->q = s->agentreq + 4; + *s->q++ = SSH2_AGENTC_SIGN_REQUEST; + PUT_32BIT(s->q, s->pklen); + s->q += 4; + memcpy(s->q, s->pkblob, s->pklen); + s->q += s->pklen; + PUT_32BIT(s->q, s->siglen); + s->q += 4; + /* Now the data to be signed... */ + if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { + PUT_32BIT(s->q, ssh->v2_session_id_len); s->q += 4; - /* Now the data to be signed... */ - if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { - PUT_32BIT(s->q, 20); - s->q += 4; - } - memcpy(s->q, ssh->v2_session_id, 20); - s->q += 20; - memcpy(s->q, s->pktout->data + 5, - s->pktout->length - 5); - s->q += s->pktout->length - 5; - /* And finally the (zero) flags word. */ - PUT_32BIT(s->q, 0); - if (!agent_query(s->agentreq, s->len + 4, - &vret, &s->retlen, - ssh_agent_callback, ssh)) { - do { - crReturnV; - if (pktin) { - bombout(("Unexpected data from server" - " while waiting for agent" - " response")); - crStopV; - } - } while (pktin || inlen > 0); - vret = ssh->agent_response; - s->retlen = ssh->agent_response_len; - } - s->ret = vret; - sfree(s->agentreq); - if (s->ret) { - if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { - logevent("Sending Pageant's response"); - ssh2_add_sigblob(ssh, s->pktout, - s->pkblob, s->pklen, - s->ret + 9, - GET_32BIT(s->ret + 5)); - ssh2_pkt_send(ssh, s->pktout); - s->authed = TRUE; - break; - } else { - logevent - ("Pageant failed to answer challenge"); - sfree(s->ret); + } + memcpy(s->q, ssh->v2_session_id, + ssh->v2_session_id_len); + s->q += ssh->v2_session_id_len; + memcpy(s->q, s->pktout->data + 5, + s->pktout->length - 5); + s->q += s->pktout->length - 5; + /* And finally the (zero) flags word. */ + PUT_32BIT(s->q, 0); + if (!agent_query(s->agentreq, s->len + 4, + &vret, &s->retlen, + ssh_agent_callback, ssh)) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server" + " while waiting for agent" + " response")); + crStopV; } + } while (pktin || inlen > 0); + vret = ssh->agent_response; + s->retlen = ssh->agent_response_len; + } + s->ret = vret; + sfree(s->agentreq); + if (s->ret) { + if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { + logevent("Sending Pageant's response"); + ssh2_add_sigblob(ssh, s->pktout, + s->pkblob, s->pklen, + s->ret + 9, + GET_32BIT(s->ret + 5)); + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_PUBLICKEY; + } else { + /* FIXME: less drastic response */ + bombout(("Pageant failed to answer challenge")); + crStopV; } } - if (s->authed) - continue; } - sfree(s->response); - } - if (!s->method && s->can_pubkey && s->publickey_blob - && !s->tried_pubkey_config) { - unsigned char *pub_blob; - char *algorithm, *comment; - int pub_blob_len; + /* Do we have any keys left to try? */ + if (s->pkblob_in_agent) { + s->done_agent = TRUE; + s->tried_pubkey_config = TRUE; + } else { + s->keyi++; + if (s->keyi >= s->nkeys) + s->done_agent = TRUE; + } - s->tried_pubkey_config = TRUE; + } else if (s->can_pubkey && s->publickey_blob && + !s->tried_pubkey_config) { + + struct ssh2_userkey *key; /* not live over crReturn */ + char *passphrase; /* not live over crReturn */ ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; + s->tried_pubkey_config = TRUE; + /* * Try the public key supplied in the configuration. * * First, offer the public blob to see if the server is * willing to accept it. */ - pub_blob = - (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile, - &algorithm, - &pub_blob_len, - NULL); - if (pub_blob) { - s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ - ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ - ssh2_pkt_addstring(s->pktout, algorithm); - ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob, - pub_blob_len); - ssh2_pkt_send(ssh, s->pktout); - logevent("Offered public key"); - - crWaitUntilV(pktin); - if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { - s->gotit = TRUE; - s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; - continue; /* key refused; give up on it */ - } - - logevent("Offer of public key accepted"); - /* - * Actually attempt a serious authentication using - * the key. - */ - if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) { - sprintf(s->pwprompt, - "Passphrase for key \"%.100s\": ", - comment); - s->need_pw = TRUE; - } else { - s->need_pw = FALSE; - } - if (flags & FLAG_VERBOSE) { - c_write_str(ssh, "Authenticating with public key \""); - c_write_str(ssh, comment); - c_write_str(ssh, "\"\r\n"); - } - s->method = AUTH_PUBLICKEY_FILE; - } - } - - if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused && - !s->kbd_inter_running) { - s->method = AUTH_KEYBOARD_INTERACTIVE; - s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; - s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */ - ssh2_pkt_addstring(s->pktout, ""); /* lang */ - ssh2_pkt_addstring(s->pktout, ""); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ + ssh2_pkt_addbool(s->pktout, FALSE); + /* no signature included */ + ssh2_pkt_addstring(s->pktout, s->publickey_algorithm); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, + (char *)s->publickey_blob, + s->publickey_bloblen); ssh2_pkt_send(ssh, s->pktout); + logevent("Offered public key"); crWaitUntilV(pktin); - if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) { - if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) - s->gotit = TRUE; - logevent("Keyboard-interactive authentication refused"); - s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; - s->kbd_inter_refused = TRUE; /* don't try it again */ - continue; - } - - c_write_str(ssh, "Using keyboard-interactive authentication.\r\n"); - s->kbd_inter_running = TRUE; - s->curr_prompt = 0; - } - - if (s->kbd_inter_running) { - s->method = AUTH_KEYBOARD_INTERACTIVE; - s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; - - if (s->curr_prompt == 0) { - /* - * We've got a fresh USERAUTH_INFO_REQUEST. - * Display header data, and start going through - * the prompts. - */ - char *name, *inst, *lang; - int name_len, inst_len, lang_len; - - ssh_pkt_getstring(pktin, &name, &name_len); - ssh_pkt_getstring(pktin, &inst, &inst_len); - ssh_pkt_getstring(pktin, &lang, &lang_len); - if (name_len > 0) { - c_write_untrusted(ssh, name, name_len); - c_write_str(ssh, "\r\n"); - } - if (inst_len > 0) { - c_write_untrusted(ssh, inst, inst_len); - c_write_str(ssh, "\r\n"); - } - s->num_prompts = ssh_pkt_getuint32(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { + /* Key refused. Give up. */ + s->gotit = TRUE; /* reconsider message next loop */ + s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; + continue; /* process this new message */ } + logevent("Offer of public key accepted"); /* - * If there are prompts remaining in the packet, - * display one and get a response. + * Actually attempt a serious authentication using + * the key. */ - if (s->curr_prompt < s->num_prompts) { - char *prompt; - int prompt_len; - - ssh_pkt_getstring(pktin, &prompt, &prompt_len); - if (prompt_len > 0) { - static const char trunc[] = ": "; - static const int prlen = sizeof(s->pwprompt) - - lenof(trunc); - if (prompt_len > prlen) { - memcpy(s->pwprompt, prompt, prlen); - strcpy(s->pwprompt + prlen, trunc); - } else { - memcpy(s->pwprompt, prompt, prompt_len); - s->pwprompt[prompt_len] = '\0'; + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticating with public key \""); + c_write_str(ssh, s->publickey_comment); + c_write_str(ssh, "\"\r\n"); + } + key = NULL; + while (!key) { + const char *error; /* not live over crReturn */ + if (s->publickey_encrypted) { + /* + * Get a passphrase from the user. + */ + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = FALSE; + s->cur_prompt->name = dupstr("SSH key passphrase"); + add_prompt(s->cur_prompt, + dupprintf("Passphrase for key \"%.100s\": ", + s->publickey_comment), + FALSE, SSH_MAX_PASSWORD_LEN); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, + in, inlen); + ssh->send_ok = 0; } + if (!ret) { + /* Failed to get a passphrase. Terminate. */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, + "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + passphrase = + dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); } else { - strcpy(s->pwprompt, - ": "); + passphrase = NULL; /* no passphrase needed */ } - s->echo = ssh2_pkt_getbool(pktin); - s->need_pw = TRUE; - } else - s->need_pw = FALSE; - } - - if (!s->method && s->can_passwd) { - s->method = AUTH_PASSWORD; - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD; - sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username, - ssh->savedhost); - s->need_pw = TRUE; - } - if (s->need_pw) { - if (ssh_get_line) { - if (!ssh_get_line(s->pwprompt, s->password, - sizeof(s->password), TRUE)) { - /* - * get_line failed to get a password (for - * example because one was supplied on the - * command line which has already failed to - * work). Terminate. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, "No more passwords available" - " to try"); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); - logevent("Unable to authenticate"); - connection_fatal(ssh->frontend, - "Unable to authenticate"); - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; + /* + * Try decrypting the key. + */ + key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase, + &error); + if (passphrase) { + /* burn the evidence */ + memset(passphrase, 0, strlen(passphrase)); + sfree(passphrase); + } + if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { + if (passphrase && + (key == SSH2_WRONG_PASSPHRASE)) { + c_write_str(ssh, "Wrong passphrase\r\n"); + key = NULL; + /* and loop again */ + } else { + c_write_str(ssh, "Unable to load private key ("); + c_write_str(ssh, error); + c_write_str(ssh, ")\r\n"); + key = NULL; + break; /* try something else */ + } } - } else { - int ret; /* need not be saved across crReturn */ - c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt)); - ssh->send_ok = 1; - - setup_userpass_input(ssh, s->password, - sizeof(s->password), s->echo); - do { - crWaitUntilV(!pktin); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); } - } - if (s->method == AUTH_PUBLICKEY_FILE) { - /* - * We have our passphrase. Now try the actual authentication. - */ - struct ssh2_userkey *key; - const char *error = NULL; - - key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password, - &error); - if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { - if (key == SSH2_WRONG_PASSPHRASE) { - c_write_str(ssh, "Wrong passphrase\r\n"); - s->tried_pubkey_config = FALSE; - } else { - c_write_str(ssh, "Unable to load private key ("); - c_write_str(ssh, error); - c_write_str(ssh, ")\r\n"); - s->tried_pubkey_config = TRUE; - } - /* Send a spurious AUTH_NONE to return to the top. */ - s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(s->pktout, "none"); /* method */ - ssh2_pkt_send(ssh, s->pktout); - s->type = AUTH_TYPE_NONE; - } else { + if (key) { unsigned char *pkblob, *sigblob, *sigdata; int pkblob_len, sigblob_len, sigdata_len; - int p; + int p; /* * We have loaded the private key and the server @@ -7169,13 +7184,18 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ ssh2_pkt_addbool(s->pktout, TRUE); + /* signature follows */ ssh2_pkt_addstring(s->pktout, key->alg->name); - pkblob = key->alg->public_blob(key->data, &pkblob_len); + pkblob = key->alg->public_blob(key->data, + &pkblob_len); ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len); + ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, + pkblob_len); /* * The data to be signed is: @@ -7185,20 +7205,23 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * followed by everything so far placed in the * outgoing packet. */ - sigdata_len = s->pktout->length - 5 + 4 + 20; - if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) - sigdata_len -= 4; + sigdata_len = s->pktout->length - 5 + 4 + + ssh->v2_session_id_len; + if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) + sigdata_len -= 4; sigdata = snewn(sigdata_len, unsigned char); - p = 0; - if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { - PUT_32BIT(sigdata+p, 20); - p += 4; - } - memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20; + p = 0; + if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { + PUT_32BIT(sigdata+p, ssh->v2_session_id_len); + p += 4; + } + memcpy(sigdata+p, ssh->v2_session_id, + ssh->v2_session_id_len); + p += ssh->v2_session_id_len; memcpy(sigdata+p, s->pktout->data + 5, s->pktout->length - 5); - p += s->pktout->length - 5; - assert(p == sigdata_len); + p += s->pktout->length - 5; + assert(p == sigdata_len); sigblob = key->alg->sign(key->data, (char *)sigdata, sigdata_len, &sigblob_len); ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len, @@ -7211,8 +7234,197 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->type = AUTH_TYPE_PUBLICKEY; key->alg->freekey(key->data); } - } else if (s->method == AUTH_PASSWORD) { + + } else if (s->can_keyb_inter && !s->kbd_inter_refused) { + + /* + * Keyboard-interactive authentication. + */ + + s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; + + ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; + ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; + + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, s->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); + /* method */ + ssh2_pkt_addstring(s->pktout, ""); /* lang */ + ssh2_pkt_addstring(s->pktout, ""); /* submethods */ + ssh2_pkt_send(ssh, s->pktout); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) { + /* Server is not willing to do keyboard-interactive + * at all (or, bizarrely but legally, accepts the + * user without actually issuing any prompts). + * Give up on it entirely. */ + s->gotit = TRUE; + if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) + logevent("Keyboard-interactive authentication refused"); + s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; + s->kbd_inter_refused = TRUE; /* don't try it again */ + continue; + } + + /* + * Loop while the server continues to send INFO_REQUESTs. + */ + while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) { + + char *name, *inst, *lang; + int name_len, inst_len, lang_len; + int i; + + /* + * We've got a fresh USERAUTH_INFO_REQUEST. + * Get the preamble and start building a prompt. + */ + ssh_pkt_getstring(pktin, &name, &name_len); + ssh_pkt_getstring(pktin, &inst, &inst_len); + ssh_pkt_getstring(pktin, &lang, &lang_len); + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + if (name_len) { + /* FIXME: better prefix to distinguish from + * local prompts? */ + s->cur_prompt->name = + dupprintf("SSH server: %.*s", name_len, name); + s->cur_prompt->name_reqd = TRUE; + } else { + s->cur_prompt->name = + dupstr("SSH server authentication"); + s->cur_prompt->name_reqd = FALSE; + } + /* FIXME: ugly to print "Using..." in prompt _every_ + * time round. Can this be done more subtly? */ + s->cur_prompt->instruction = + dupprintf("Using keyboard-interactive authentication.%s%.*s", + inst_len ? "\n" : "", inst_len, inst); + s->cur_prompt->instr_reqd = TRUE; + + /* + * Get the prompts from the packet. + */ + s->num_prompts = ssh_pkt_getuint32(pktin); + for (i = 0; i < s->num_prompts; i++) { + char *prompt; + int prompt_len; + int echo; + static char noprompt[] = + ": "; + + ssh_pkt_getstring(pktin, &prompt, &prompt_len); + echo = ssh2_pkt_getbool(pktin); + if (!prompt_len) { + prompt = noprompt; + prompt_len = lenof(noprompt)-1; + } + add_prompt(s->cur_prompt, + dupprintf("%.*s", prompt_len, prompt), + echo, SSH_MAX_PASSWORD_LEN); + } + + /* + * Get the user's responses. + */ + if (s->num_prompts) { + int ret; /* not live over crReturn */ + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + } + + /* + * Send the responses to the server. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); + s->pktout->forcepad = 256; + ssh2_pkt_adduint32(s->pktout, s->num_prompts); + for (i=0; i < s->num_prompts; i++) { + dont_log_password(ssh, s->pktout, PKTLOG_BLANK); + ssh2_pkt_addstring(s->pktout, + s->cur_prompt->prompts[i]->result); + end_log_omission(ssh, s->pktout); + } + ssh2_pkt_send(ssh, s->pktout); + + /* + * Get the next packet in case it's another + * INFO_REQUEST. + */ + crWaitUntilV(pktin); + + } + /* + * We should have SUCCESS or FAILURE now. + */ + s->gotit = TRUE; + + } else if (s->can_passwd) { + + /* + * Plain old password authentication. + */ + int ret; /* not live over crReturn */ + int changereq_first_time; /* not live over crReturn */ + + ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; + ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD; + + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH password"); + add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ", + s->username, + ssh->savedhost), + FALSE, SSH_MAX_PASSWORD_LEN); + + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + /* + * Squirrel away the password. (We may need it later if + * asked to change it.) + */ + s->password = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + + /* + * Send the password packet. + * * We pad out the password packet to 256 bytes to make * it harder for an attacker to find the length of the * user's password. @@ -7224,62 +7436,173 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); s->pktout->forcepad = 256; ssh2_pkt_addstring(s->pktout, s->username); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ ssh2_pkt_addstring(s->pktout, "password"); ssh2_pkt_addbool(s->pktout, FALSE); dont_log_password(ssh, s->pktout, PKTLOG_BLANK); ssh2_pkt_addstring(s->pktout, s->password); - memset(s->password, 0, sizeof(s->password)); end_log_omission(ssh, s->pktout); ssh2_pkt_send(ssh, s->pktout); logevent("Sent password"); s->type = AUTH_TYPE_PASSWORD; - } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) { - if (s->curr_prompt == 0) { - s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); + + /* + * Wait for next packet, in case it's a password change + * request. + */ + crWaitUntilV(pktin); + changereq_first_time = TRUE; + + while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { + + /* + * We're being asked for a new password + * (perhaps not for the first time). + * Loop until the server accepts it. + */ + + int got_new = FALSE; /* not live over crReturn */ + char *prompt; /* not live over crReturn */ + int prompt_len; /* not live over crReturn */ + + { + char *msg; + if (changereq_first_time) + msg = "Server requested password change"; + else + msg = "Server rejected new password"; + logevent(msg); + c_write_str(ssh, msg); + c_write_str(ssh, "\r\n"); + } + + ssh_pkt_getstring(pktin, &prompt, &prompt_len); + + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("New SSH password"); + s->cur_prompt->instruction = + dupprintf("%.*s", prompt_len, prompt); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, dupstr("Enter new password: "), + FALSE, SSH_MAX_PASSWORD_LEN); + add_prompt(s->cur_prompt, dupstr("Confirm new password: "), + FALSE, SSH_MAX_PASSWORD_LEN); + + /* + * Loop until the user manages to enter the same + * password twice. + */ + while (!got_new) { + + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + /* burn the evidence */ + free_prompts(s->cur_prompt); + memset(s->password, 0, strlen(s->password)); + sfree(s->password); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + + /* + * Check the two passwords match. + */ + got_new = (strcmp(s->cur_prompt->prompts[0]->result, + s->cur_prompt->prompts[1]->result) + == 0); + if (!got_new) + /* They don't. Silly user. */ + c_write_str(ssh, "Passwords do not match\r\n"); + + } + + /* + * Send the new password (along with the old one). + * (see above for padding rationale) + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); s->pktout->forcepad = 256; - ssh2_pkt_adduint32(s->pktout, s->num_prompts); - } - if (s->need_pw) { /* only add pw if we just got one! */ + ssh2_pkt_addstring(s->pktout, s->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "password"); + ssh2_pkt_addbool(s->pktout, TRUE); dont_log_password(ssh, s->pktout, PKTLOG_BLANK); ssh2_pkt_addstring(s->pktout, s->password); - memset(s->password, 0, sizeof(s->password)); + ssh2_pkt_addstring(s->pktout, + s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); end_log_omission(ssh, s->pktout); - s->curr_prompt++; - } - if (s->curr_prompt >= s->num_prompts) { ssh2_pkt_send(ssh, s->pktout); - } else { + logevent("Sent new password"); + /* - * If there are prompts remaining, we set - * `gotit' so that we won't attempt to get - * another packet. Then we go back round the - * loop and will end up retrieving another - * prompt out of the existing packet. Funky or - * what? + * Now see what the server has to say about it. + * (If it's CHANGEREQ again, it's not happy with the + * new password.) */ - s->gotit = TRUE; + crWaitUntilV(pktin); + changereq_first_time = FALSE; + } - s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; + + /* + * We need to reexamine the current pktin at the top + * of the loop. Either: + * - we weren't asked to change password at all, in + * which case it's a SUCCESS or FAILURE with the + * usual meaning + * - we sent a new password, and the server was + * either OK with it (SUCCESS or FAILURE w/partial + * success) or unhappy with the _old_ password + * (FAILURE w/o partial success) + * In any of these cases, we go back to the top of + * the loop and start again. + */ + s->gotit = TRUE; + + /* + * We don't need the old password any more, in any + * case. Burn the evidence. + */ + memset(s->password, 0, strlen(s->password)); + sfree(s->password); + } else { - c_write_str(ssh, "No supported authentication methods" - " left to try!\r\n"); - logevent("No supported authentications offered." - " Disconnecting"); - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, "No supported authentication" - " methods available"); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); - ssh->close_expected = TRUE; - ssh_closing((Plug)ssh, NULL, 0, 0); + + ssh_disconnect(ssh, NULL, + "No supported authentication methods available", + SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, + FALSE); crStopV; + } + } } ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; + /* Clear up various bits and pieces from authentication. */ + if (s->publickey_blob) { + sfree(s->publickey_blob); + sfree(s->publickey_comment); + } + if (s->agent_response) + sfree(s->agent_response); + /* * Now the connection protocol has started, one way or another. */ @@ -7847,6 +8170,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->hostkey = NULL; ssh->exitcode = -1; ssh->close_expected = FALSE; + ssh->clean_exit = FALSE; ssh->state = SSH_STATE_PREPACKET; ssh->size_needed = FALSE; ssh->eof_needed = FALSE; @@ -7872,6 +8196,8 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->do_ssh1_login_state = NULL; ssh->do_ssh2_transport_state = NULL; ssh->do_ssh2_authconn_state = NULL; + ssh->v_c = NULL; + ssh->v_s = NULL; ssh->mainchan = NULL; ssh->throttled_all = 0; ssh->v1_stdout_throttling = 0; @@ -7999,6 +8325,8 @@ static void ssh_free(void *handle) sfree(ssh->do_ssh1_login_state); sfree(ssh->do_ssh2_transport_state); sfree(ssh->do_ssh2_authconn_state); + sfree(ssh->v_c); + sfree(ssh->v_s); if (ssh->crcda_ctx) { crcda_free_context(ssh->crcda_ctx); ssh->crcda_ctx = NULL; @@ -8072,7 +8400,7 @@ static void ssh_reconfig(void *handle, Config *cfg) } /* - * Called to send data down the Telnet connection. + * Called to send data down the SSH connection. */ static int ssh_send(void *handle, char *buf, int len) { @@ -8229,7 +8557,7 @@ static const struct telnet_special *ssh_get_specials(void *handle) } /* - * Send Telnet special codes. TS_EOF is useful for `plink', so you + * Send special codes. TS_EOF is useful for `plink', so you * can send an EOF and collect resulting output (e.g. `plink * hostname sort'). */ @@ -8386,8 +8714,11 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org) * too much hassle to keep track, and partly I'm not * convinced the server should be told details like that * about my local network configuration. + * The "originator IP address" is syntactically a numeric + * IP address, and some servers (e.g., Tectia) get upset + * if it doesn't match this syntax. */ - ssh2_pkt_addstring(pktout, "client-side-connection"); + ssh2_pkt_addstring(pktout, "0.0.0.0"); ssh2_pkt_adduint32(pktout, 0); ssh2_pkt_send(ssh, pktout); }