X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/2247e1074900998db819ae18bdc33d7100bc4e7f..70637309a61321d83a4d0576b875b7dcb7085fa5:/sshpubk.c diff --git a/sshpubk.c b/sshpubk.c index f8cb38b0..9e89fe97 100644 --- a/sshpubk.c +++ b/sshpubk.c @@ -9,6 +9,7 @@ #include #include +#include "putty.h" #include "ssh.h" #include "misc.h" @@ -33,7 +34,8 @@ (x)=='/' ? 63 : 0 ) static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, - char **commentptr, char *passphrase) + char **commentptr, char *passphrase, + const char **error) { unsigned char buf[16384]; unsigned char keybuf[16]; @@ -43,13 +45,18 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, struct MD5Context md5c; char *comment; + *error = NULL; + /* Slurp the whole file (minus the header) into a buffer. */ len = fread(buf, 1, sizeof(buf), fp); fclose(fp); - if (len < 0 || len == sizeof(buf)) + if (len < 0 || len == sizeof(buf)) { + *error = "error reading file"; goto end; /* file too big or not read */ + } i = 0; + *error = "file format error"; /* * A zero byte. (The signature includes a terminating NUL.) @@ -72,8 +79,8 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, i += 4; /* Now the serious stuff. An ordinary SSH 1 public key. */ - i += makekey(buf + i, key, NULL, 1); - if (len - i < 0) + i += makekey(buf + i, len, key, NULL, 1); + if (i < 0) goto end; /* overran */ if (pub_only) { @@ -86,7 +93,7 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, i += 4; if (len - i < j) goto end; - comment = smalloc(j + 1); + comment = snewn(j + 1, char); if (comment) { memcpy(comment, buf + i, j); comment[j] = '\0'; @@ -97,7 +104,9 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, if (key) key->comment = comment; if (!key) { - return ciphertype != 0; + ret = ciphertype != 0; + *error = NULL; + goto end; } /* @@ -118,6 +127,7 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, if (len - i < 4) goto end; if (buf[i] != buf[i + 2] || buf[i + 1] != buf[i + 3]) { + *error = "wrong passphrase"; ret = -1; goto end; } @@ -128,20 +138,21 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, * decryption exponent, and then the three auxiliary values * (iqmp, q, p). */ - i += makeprivate(buf + i, key); - if (len - i < 0) - goto end; - i += ssh1_read_bignum(buf + i, &key->iqmp); - if (len - i < 0) - goto end; - i += ssh1_read_bignum(buf + i, &key->q); - if (len - i < 0) - goto end; - i += ssh1_read_bignum(buf + i, &key->p); - if (len - i < 0) - goto end; + j = makeprivate(buf + i, len - i, key); + if (j < 0) goto end; + i += j; + j = ssh1_read_bignum(buf + i, len - i, &key->iqmp); + if (j < 0) goto end; + i += j; + j = ssh1_read_bignum(buf + i, len - i, &key->q); + if (j < 0) goto end; + i += j; + j = ssh1_read_bignum(buf + i, len - i, &key->p); + if (j < 0) goto end; + i += j; if (!rsa_verify(key)) { + *error = "rsa_verify failed"; freersakey(key); ret = 0; } else @@ -152,40 +163,56 @@ static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only, return ret; } -int loadrsakey(char *filename, struct RSAKey *key, char *passphrase) +int loadrsakey(const Filename *filename, struct RSAKey *key, char *passphrase, + const char **errorstr) { FILE *fp; char buf[64]; + int ret = 0; + const char *error = NULL; - fp = fopen(filename, "rb"); - if (!fp) - return 0; /* doesn't even exist */ + fp = f_open(*filename, "rb"); + if (!fp) { + error = "can't open file"; + goto end; + } /* * Read the first line of the file and see if it's a v1 private * key file. */ if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) { - return loadrsakey_main(fp, key, FALSE, NULL, passphrase); + /* + * This routine will take care of calling fclose() for us. + */ + ret = loadrsakey_main(fp, key, FALSE, NULL, passphrase, &error); + fp = NULL; + goto end; } /* * Otherwise, we have nothing. Return empty-handed. */ - fclose(fp); - return 0; + error = "not an SSH-1 RSA file"; + + end: + if (fp) + fclose(fp); + if ((ret != 1) && errorstr) + *errorstr = error; + return ret; } /* * See whether an RSA key is encrypted. Return its comment field as * well. */ -int rsakey_encrypted(char *filename, char **comment) +int rsakey_encrypted(const Filename *filename, char **comment) { FILE *fp; char buf[64]; - fp = fopen(filename, "rb"); + fp = f_open(*filename, "rb"); if (!fp) return 0; /* doesn't even exist */ @@ -194,7 +221,11 @@ int rsakey_encrypted(char *filename, char **comment) * key file. */ if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) { - return loadrsakey_main(fp, NULL, FALSE, comment, NULL); + const char *dummy; + /* + * This routine will take care of calling fclose() for us. + */ + return loadrsakey_main(fp, NULL, FALSE, comment, NULL, &dummy); } fclose(fp); return 0; /* wasn't the right kind of file */ @@ -205,21 +236,25 @@ int rsakey_encrypted(char *filename, char **comment) * an RSA key, as given in the agent protocol (modulus bits, * exponent, modulus). */ -int rsakey_pubblob(char *filename, void **blob, int *bloblen) +int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen, + const char **errorstr) { FILE *fp; char buf[64]; struct RSAKey key; int ret; + const char *error = NULL; /* Default return if we fail. */ *blob = NULL; *bloblen = 0; ret = 0; - fp = fopen(filename, "rb"); - if (!fp) - return 0; /* doesn't even exist */ + fp = f_open(*filename, "rb"); + if (!fp) { + error = "can't open file"; + goto end; + } /* * Read the first line of the file and see if it's a v1 private @@ -227,20 +262,28 @@ int rsakey_pubblob(char *filename, void **blob, int *bloblen) */ if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) { memset(&key, 0, sizeof(key)); - if (loadrsakey_main(fp, &key, TRUE, NULL, NULL)) { + if (loadrsakey_main(fp, &key, TRUE, NULL, NULL, &error)) { *blob = rsa_public_blob(&key, bloblen); freersakey(&key); ret = 1; + fp = NULL; } + } else { + error = "not an SSH-1 RSA file"; } - fclose(fp); + + end: + if (fp) + fclose(fp); + if ((ret != 1) && errorstr) + *errorstr = error; return ret; } /* * Save an RSA key file. Return nonzero on success. */ -int saversakey(char *filename, struct RSAKey *key, char *passphrase) +int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase) { unsigned char buf[16384]; unsigned char keybuf[16]; @@ -330,10 +373,11 @@ int saversakey(char *filename, struct RSAKey *key, char *passphrase) /* * Done. Write the result to the file. */ - fp = fopen(filename, "wb"); + fp = f_open(*filename, "wb"); if (fp) { int ret = (fwrite(buf, 1, p - buf, fp) == (size_t) (p - buf)); - ret = ret && (fclose(fp) == 0); + if (fclose(fp)) + ret = 0; return ret; } else return 0; @@ -400,8 +444,7 @@ int saversakey(char *filename, struct RSAKey *key, char *passphrase) * data "putty-private-key-file-mac-key" * data passphrase * - * Encrypted keys should have a MAC, whereas unencrypted ones must - * have a hash. + * (An empty passphrase is used for unencrypted keys.) * * If the key is encrypted, the encryption key is derived from the * passphrase by means of a succession of SHA-1 hashes. Each hash @@ -456,7 +499,7 @@ static char *read_body(FILE * fp) int c; size = 128; - text = smalloc(size); + text = snewn(size, char); len = 0; text[len] = '\0'; @@ -474,7 +517,7 @@ static char *read_body(FILE * fp) } if (len + 1 > size) { size += 128; - text = srealloc(text, size); + text = sresize(text, size, char); } text[len++] = c; text[len] = '\0'; @@ -537,7 +580,7 @@ static unsigned char *read_blob(FILE * fp, int nlines, int *bloblen) int i, j, k; /* We expect at most 64 base64 characters, ie 48 real bytes, per line. */ - blob = smalloc(48 * nlines); + blob = snewn(48 * nlines, unsigned char); len = 0; for (i = 0; i < nlines; i++) { line = read_body(fp); @@ -573,7 +616,18 @@ struct ssh2_userkey ssh2_wrong_passphrase = { NULL, NULL, NULL }; -struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) +const struct ssh_signkey *find_pubkey_alg(const char *name) +{ + if (!strcmp(name, "ssh-rsa")) + return &ssh_rsa; + else if (!strcmp(name, "ssh-dss")) + return &ssh_dss; + else + return NULL; +} + +struct ssh2_userkey *ssh2_load_userkey(const Filename *filename, + char *passphrase, const char **errorstr) { FILE *fp; char header[40], *b, *encryption, *comment, *mac; @@ -584,14 +638,17 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) int public_blob_len, private_blob_len; int i, is_mac, old_fmt; int passlen = passphrase ? strlen(passphrase) : 0; + const char *error = NULL; ret = NULL; /* return NULL for most errors */ - comment = mac = NULL; + encryption = comment = mac = NULL; public_blob = private_blob = NULL; - fp = fopen(filename, "rb"); - if (!fp) + fp = f_open(*filename, "rb"); + if (!fp) { + error = "can't open file"; goto error; + } /* Read the first header line which contains the key type. */ if (!read_header(fp, header)) @@ -602,16 +659,16 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) /* this is an old key file; warn and then continue */ old_keyfile_warning(); old_fmt = 1; - } else + } else { + error = "not a PuTTY SSH-2 private key"; goto error; + } + error = "file format error"; if ((b = read_body(fp)) == NULL) goto error; /* Select key algorithm structure. */ - if (!strcmp(b, "ssh-rsa")) - alg = &ssh_rsa; - else if (!strcmp(b, "ssh-dss")) - alg = &ssh_dss; - else { + alg = find_pubkey_alg(b); + if (!alg) { sfree(b); goto error; } @@ -725,7 +782,7 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) 4 + commlen + 4 + public_blob_len + 4 + private_blob_len); - macdata = smalloc(maclen); + macdata = snewn(maclen, unsigned char); p = macdata; #define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len) DO_STR(alg->name, namelen); @@ -744,7 +801,7 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) SHA_Init(&s); SHA_Bytes(&s, header, sizeof(header)-1); - if (passphrase) + if (cipher && passphrase) SHA_Bytes(&s, passphrase, passlen); SHA_Final(&s, mackey); @@ -767,7 +824,13 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) if (strcmp(mac, realmac)) { /* An incorrect MAC is an unconditional Error if the key is * unencrypted. Otherwise, it means Wrong Passphrase. */ - ret = cipher ? SSH2_WRONG_PASSPHRASE : NULL; + if (cipher) { + error = "wrong passphrase"; + ret = SSH2_WRONG_PASSPHRASE; + } else { + error = "MAC failed"; + ret = NULL; + } goto error; } } @@ -776,7 +839,7 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) /* * Create and return the key. */ - ret = smalloc(sizeof(struct ssh2_userkey)); + ret = snew(struct ssh2_userkey); ret->alg = alg; ret->comment = comment; ret->data = alg->createkey(public_blob, public_blob_len, @@ -785,10 +848,14 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) sfree(ret->comment); sfree(ret); ret = NULL; + error = "createkey failed"; + goto error; } sfree(public_blob); sfree(private_blob); sfree(encryption); + if (errorstr) + *errorstr = NULL; return ret; /* @@ -807,11 +874,13 @@ struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase) sfree(public_blob); if (private_blob) sfree(private_blob); + if (errorstr) + *errorstr = error; return ret; } -char *ssh2_userkey_loadpub(char *filename, char **algorithm, - int *pub_blob_len) +char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm, + int *pub_blob_len, const char **errorstr) { FILE *fp; char header[40], *b; @@ -819,26 +888,29 @@ char *ssh2_userkey_loadpub(char *filename, char **algorithm, unsigned char *public_blob; int public_blob_len; int i; + const char *error = NULL; public_blob = NULL; - fp = fopen(filename, "rb"); - if (!fp) + fp = f_open(*filename, "rb"); + if (!fp) { + error = "can't open file"; goto error; + } /* Read the first header line which contains the key type. */ if (!read_header(fp, header) || (0 != strcmp(header, "PuTTY-User-Key-File-2") && - 0 != strcmp(header, "PuTTY-User-Key-File-1"))) + 0 != strcmp(header, "PuTTY-User-Key-File-1"))) { + error = "not a PuTTY SSH-2 private key"; goto error; + } + error = "file format error"; if ((b = read_body(fp)) == NULL) goto error; /* Select key algorithm structure. Currently only ssh-rsa. */ - if (!strcmp(b, "ssh-rsa")) - alg = &ssh_rsa; - else if (!strcmp(b, "ssh-dss")) - alg = &ssh_dss; - else { + alg = find_pubkey_alg(b); + if (!alg) { sfree(b); goto error; } @@ -883,10 +955,12 @@ char *ssh2_userkey_loadpub(char *filename, char **algorithm, fclose(fp); if (public_blob) sfree(public_blob); + if (errorstr) + *errorstr = error; return NULL; } -int ssh2_userkey_encrypted(char *filename, char **commentptr) +int ssh2_userkey_encrypted(const Filename *filename, char **commentptr) { FILE *fp; char header[40], *b, *comment; @@ -895,7 +969,7 @@ int ssh2_userkey_encrypted(char *filename, char **commentptr) if (commentptr) *commentptr = NULL; - fp = fopen(filename, "rb"); + fp = f_open(*filename, "rb"); if (!fp) return 0; if (!read_header(fp, header) @@ -972,7 +1046,7 @@ void base64_encode(FILE * fp, unsigned char *data, int datalen, int cpl) fputc('\n', fp); } -int ssh2_save_userkey(char *filename, struct ssh2_userkey *key, +int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key, char *passphrase) { FILE *fp; @@ -1007,7 +1081,7 @@ int ssh2_save_userkey(char *filename, struct ssh2_userkey *key, } priv_encrypted_len = priv_blob_len + cipherblk - 1; priv_encrypted_len -= priv_encrypted_len % cipherblk; - priv_blob_encrypted = smalloc(priv_encrypted_len); + priv_blob_encrypted = snewn(priv_encrypted_len, unsigned char); memset(priv_blob_encrypted, 0, priv_encrypted_len); memcpy(priv_blob_encrypted, priv_blob, priv_blob_len); /* Create padding based on the SHA hash of the unpadded blob. This prevents @@ -1034,7 +1108,7 @@ int ssh2_save_userkey(char *filename, struct ssh2_userkey *key, 4 + commlen + 4 + pub_blob_len + 4 + priv_encrypted_len); - macdata = smalloc(maclen); + macdata = snewn(maclen, unsigned char); p = macdata; #define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len) DO_STR(key->alg->name, namelen); @@ -1076,7 +1150,7 @@ int ssh2_save_userkey(char *filename, struct ssh2_userkey *key, memset(&s, 0, sizeof(s)); } - fp = fopen(filename, "w"); + fp = f_open(*filename, "w"); if (!fp) return 0; fprintf(fp, "PuTTY-User-Key-File-2: %s\n", key->alg->name); @@ -1103,7 +1177,7 @@ int ssh2_save_userkey(char *filename, struct ssh2_userkey *key, * A function to determine the type of a private key file. Returns * 0 on failure, 1 or 2 on success. */ -int key_type(char *filename) +int key_type(const Filename *filename) { FILE *fp; char buf[32]; @@ -1112,7 +1186,7 @@ int key_type(char *filename) const char openssh_sig[] = "-----BEGIN "; int i; - fp = fopen(filename, "r"); + fp = f_open(*filename, "r"); if (!fp) return SSH_KEYTYPE_UNOPENABLE; i = fread(buf, 1, sizeof(buf), fp);