Jacob's TIS / CCard authentication tweaks.

[u/mdw/putty] / ssh.c

diff --git a/ssh.c b/ssh.c
index e793412..23cfdaa 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -1794,6 +1794,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
     struct MD5Context md5c;
     static unsigned long supported_ciphers_mask, supported_auths_mask;
     static int tried_publickey;
+    static int tis_auth_refused, ccard_auth_refused;
     static unsigned char session_id[16];
     static int cipher_type;
     static char username[100];
@@ -2042,6 +2043,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
     crWaitUntil(ispkt);
 
     tried_publickey = 0;
+    tis_auth_refused = ccard_auth_refused = 0;
 
     while (pktin.type == SSH1_SMSG_FAILURE) {
        static char password[100];
@@ -2049,12 +2051,8 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
        static int pos;
        static char c;
        static int pwpkt_type;
-       /*
-        * Show password prompt, having first obtained it via a TIS
-        * or CryptoCard exchange if we're doing TIS or CryptoCard
-        * authentication.
-        */
        pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
+
        if (agent_exists()) {
            /*
             * Attempt RSA authentication using Pageant.
@@ -2177,9 +2175,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
        if (*cfg.keyfile && !tried_publickey)
            pwpkt_type = SSH1_CMSG_AUTH_RSA;
 
-       if (pktin.type == SSH1_SMSG_FAILURE &&
-           cfg.try_tis_auth &&
-           (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
+       if (cfg.try_tis_auth &&
+           (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
+           !tis_auth_refused) {
            pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
            logevent("Requested TIS authentication");
            send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
@@ -2188,6 +2186,8 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                logevent("TIS authentication declined");
                if (flags & FLAG_INTERACTIVE)
                    c_write_str("TIS authentication refused.\r\n");
+               tis_auth_refused = 1;
+               continue;
            } else {
                int challengelen = ((pktin.body[0] << 24) |
                                    (pktin.body[1] << 16) |
@@ -2197,12 +2197,17 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                if (challengelen > sizeof(prompt) - 1)
                    challengelen = sizeof(prompt) - 1;  /* prevent overrun */
                memcpy(prompt, pktin.body + 4, challengelen);
-               prompt[challengelen] = '\0';
+               /* Prompt heuristic comes from OpenSSH */
+               strncpy(prompt + challengelen,
+                       memchr(prompt, '\n', challengelen) ?
+                       "": "\r\nResponse: ",
+                       (sizeof prompt) - challengelen);
+               prompt[(sizeof prompt) - 1] = '\0';
            }
        }
-       if (pktin.type == SSH1_SMSG_FAILURE &&
-           cfg.try_tis_auth &&
-           (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
+       if (cfg.try_tis_auth &&
+           (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
+           !ccard_auth_refused) {
            pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
            logevent("Requested CryptoCard authentication");
            send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
@@ -2210,6 +2215,8 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
            if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
                logevent("CryptoCard authentication declined");
                c_write_str("CryptoCard authentication refused.\r\n");
+               ccard_auth_refused = 1;
+               continue;
            } else {
                int challengelen = ((pktin.body[0] << 24) |
                                    (pktin.body[1] << 16) |
@@ -2219,7 +2226,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                if (challengelen > sizeof(prompt) - 1)
                    challengelen = sizeof(prompt) - 1;  /* prevent overrun */
                memcpy(prompt, pktin.body + 4, challengelen);
-               strncpy(prompt + challengelen, "\r\nResponse : ",
+               strncpy(prompt + challengelen,
+                       memchr(prompt, '\n', challengelen) ?
+                       "" : "\r\nResponse: ",
                        sizeof(prompt) - challengelen);
                prompt[sizeof(prompt) - 1] = '\0';
            }
@@ -2241,6 +2250,11 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
            sfree(comment);
        }
 
+       /*
+        * Show password prompt, having first obtained it via a TIS
+        * or CryptoCard exchange if we're doing TIS or CryptoCard
+        * authentication.
+        */
        if (ssh_get_line) {
            if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
                /*
@@ -2256,7 +2270,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                crReturn(1);
            }
        } else {
-           c_write_str(prompt);
+           /* Prompt may have come from server. We've munged it a bit, so
+            * we know it to be zero-terminated at least once. */
+           c_write_untrusted(prompt, strlen(prompt));
            pos = 0;
            ssh_send_ok = 1;
            while (pos >= 0) {
@@ -2305,7 +2321,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
            tried_publickey = 1;
            i = loadrsakey(cfg.keyfile, &pubkey, password);
            if (i == 0) {
-               c_write_str("Couldn't load public key from ");
+               c_write_str("Couldn't load private key from ");
                c_write_str(cfg.keyfile);
                c_write_str(".\r\n");
                continue;              /* go and try password */