2 * Generic SSH public-key handling operations. In particular,
3 * reading of SSH public-key files, and also the generic `sign'
4 * operation for ssh2 (which checks the type of the key and
5 * dispatches to the appropriate key-type specific function).
16 #define PUT_32BIT(cp, value) do { \
18 (cp)[2] = (value) >> 8; \
19 (cp)[1] = (value) >> 16; \
20 (cp)[0] = (value) >> 24; } while (0)
22 #define GET_32BIT(cp) \
23 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
24 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
25 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
26 ((unsigned long)(unsigned char)(cp)[3]))
28 #define rsa_signature "SSH PRIVATE KEY FILE FORMAT 1.1\n"
30 #define BASE64_TOINT(x) ( (x)-'A'<26 ? (x)-'A'+0 :\
31 (x)-'a'<26 ? (x)-'a'+26 :\
32 (x)-'0'<10 ? (x)-'0'+52 :\
36 static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only,
37 char **commentptr, char *passphrase,
40 unsigned char buf[16384];
41 unsigned char keybuf[16];
45 struct MD5Context md5c;
50 /* Slurp the whole file (minus the header) into a buffer. */
51 len = fread(buf, 1, sizeof(buf), fp);
53 if (len < 0 || len == sizeof(buf)) {
54 *error = "error reading file";
55 goto end; /* file too big or not read */
59 *error = "file format error";
62 * A zero byte. (The signature includes a terminating NUL.)
64 if (len - i < 1 || buf[i] != 0)
68 /* One byte giving encryption type, and one reserved uint32. */
72 if (ciphertype != 0 && ciphertype != SSH_CIPHER_3DES)
76 goto end; /* reserved field not present */
77 if (buf[i] != 0 || buf[i + 1] != 0 || buf[i + 2] != 0
78 || buf[i + 3] != 0) goto end; /* reserved field nonzero, panic! */
81 /* Now the serious stuff. An ordinary SSH 1 public key. */
82 i += makekey(buf + i, len, key, NULL, 1);
84 goto end; /* overran */
91 /* Next, the comment field. */
92 j = GET_32BIT(buf + i);
96 comment = snewn(j + 1, char);
98 memcpy(comment, buf + i, j);
103 *commentptr = comment;
105 key->comment = comment;
107 ret = ciphertype != 0;
113 * Decrypt remainder of buffer.
117 MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
118 MD5Final(keybuf, &md5c);
119 des3_decrypt_pubkey(keybuf, buf + i, (len - i + 7) & ~7);
120 memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
124 * We are now in the secret part of the key. The first four
125 * bytes should be of the form a, b, a, b.
129 if (buf[i] != buf[i + 2] || buf[i + 1] != buf[i + 3]) {
130 *error = "wrong passphrase";
137 * After that, we have one further bignum which is our
138 * decryption exponent, and then the three auxiliary values
141 j = makeprivate(buf + i, len - i, key);
144 j = ssh1_read_bignum(buf + i, len - i, &key->iqmp);
147 j = ssh1_read_bignum(buf + i, len - i, &key->q);
150 j = ssh1_read_bignum(buf + i, len - i, &key->p);
154 if (!rsa_verify(key)) {
155 *error = "rsa_verify failed";
162 memset(buf, 0, sizeof(buf)); /* burn the evidence */
166 int loadrsakey(const Filename *filename, struct RSAKey *key, char *passphrase,
167 const char **errorstr)
172 const char *error = NULL;
174 fp = f_open(*filename, "rb");
176 error = "can't open file";
181 * Read the first line of the file and see if it's a v1 private
184 if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
186 * This routine will take care of calling fclose() for us.
188 ret = loadrsakey_main(fp, key, FALSE, NULL, passphrase, &error);
194 * Otherwise, we have nothing. Return empty-handed.
196 error = "not an SSH-1 RSA file";
201 if ((ret != 1) && errorstr)
207 * See whether an RSA key is encrypted. Return its comment field as
210 int rsakey_encrypted(const Filename *filename, char **comment)
215 fp = f_open(*filename, "rb");
217 return 0; /* doesn't even exist */
220 * Read the first line of the file and see if it's a v1 private
223 if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
226 * This routine will take care of calling fclose() for us.
228 return loadrsakey_main(fp, NULL, FALSE, comment, NULL, &dummy);
231 return 0; /* wasn't the right kind of file */
235 * Return a malloc'ed chunk of memory containing the public blob of
236 * an RSA key, as given in the agent protocol (modulus bits,
237 * exponent, modulus).
239 int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
240 const char **errorstr)
246 const char *error = NULL;
248 /* Default return if we fail. */
253 fp = f_open(*filename, "rb");
255 error = "can't open file";
260 * Read the first line of the file and see if it's a v1 private
263 if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
264 memset(&key, 0, sizeof(key));
265 if (loadrsakey_main(fp, &key, TRUE, NULL, NULL, &error)) {
266 *blob = rsa_public_blob(&key, bloblen);
272 error = "not an SSH-1 RSA file";
278 if ((ret != 1) && errorstr)
284 * Save an RSA key file. Return nonzero on success.
286 int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase)
288 unsigned char buf[16384];
289 unsigned char keybuf[16];
290 struct MD5Context md5c;
291 unsigned char *p, *estart;
295 * Write the initial signature.
298 memcpy(p, rsa_signature, sizeof(rsa_signature));
299 p += sizeof(rsa_signature);
302 * One byte giving encryption type, and one reserved (zero)
305 *p++ = (passphrase ? SSH_CIPHER_3DES : 0);
310 * An ordinary SSH 1 public key consists of: a uint32
311 * containing the bit count, then two bignums containing the
312 * modulus and exponent respectively.
314 PUT_32BIT(p, bignum_bitcount(key->modulus));
316 p += ssh1_write_bignum(p, key->modulus);
317 p += ssh1_write_bignum(p, key->exponent);
320 * A string containing the comment field.
323 PUT_32BIT(p, strlen(key->comment));
325 memcpy(p, key->comment, strlen(key->comment));
326 p += strlen(key->comment);
333 * The encrypted portion starts here.
338 * Two bytes, then the same two bytes repeated.
340 *p++ = random_byte();
341 *p++ = random_byte();
347 * Four more bignums: the decryption exponent, then iqmp, then
350 p += ssh1_write_bignum(p, key->private_exponent);
351 p += ssh1_write_bignum(p, key->iqmp);
352 p += ssh1_write_bignum(p, key->q);
353 p += ssh1_write_bignum(p, key->p);
356 * Now write zeros until the encrypted portion is a multiple of
359 while ((p - estart) % 8)
363 * Now encrypt the encrypted portion.
367 MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
368 MD5Final(keybuf, &md5c);
369 des3_encrypt_pubkey(keybuf, estart, p - estart);
370 memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
374 * Done. Write the result to the file.
376 fp = f_open(*filename, "wb");
378 int ret = (fwrite(buf, 1, p - buf, fp) == (size_t) (p - buf));
379 ret = ret && (fclose(fp) == 0);
385 /* ----------------------------------------------------------------------
386 * SSH2 private key load/store functions.
390 * PuTTY's own format for SSH2 keys is as follows:
392 * The file is text. Lines are terminated by CRLF, although CR-only
393 * and LF-only are tolerated on input.
395 * The first line says "PuTTY-User-Key-File-2: " plus the name of the
396 * algorithm ("ssh-dss", "ssh-rsa" etc).
398 * The next line says "Encryption: " plus an encryption type.
399 * Currently the only supported encryption types are "aes256-cbc"
402 * The next line says "Comment: " plus the comment string.
404 * Next there is a line saying "Public-Lines: " plus a number N.
405 * The following N lines contain a base64 encoding of the public
406 * part of the key. This is encoded as the standard SSH2 public key
407 * blob (with no initial length): so for RSA, for example, it will
414 * Next, there is a line saying "Private-Lines: " plus a number N,
415 * and then N lines containing the (potentially encrypted) private
416 * part of the key. For the key type "ssh-rsa", this will be
419 * mpint private_exponent
420 * mpint p (the larger of the two primes)
421 * mpint q (the smaller prime)
422 * mpint iqmp (the inverse of q modulo p)
423 * data padding (to reach a multiple of the cipher block size)
425 * And for "ssh-dss", it will be composed of
427 * mpint x (the private key parameter)
428 * [ string hash 20-byte hash of mpints p || q || g only in old format ]
430 * Finally, there is a line saying "Private-MAC: " plus a hex
431 * representation of a HMAC-SHA-1 of:
433 * string name of algorithm ("ssh-dss", "ssh-rsa")
434 * string encryption type
437 * string private-plaintext (the plaintext version of the
438 * private part, including the final
441 * The key to the MAC is itself a SHA-1 hash of:
443 * data "putty-private-key-file-mac-key"
446 * (An empty passphrase is used for unencrypted keys.)
448 * If the key is encrypted, the encryption key is derived from the
449 * passphrase by means of a succession of SHA-1 hashes. Each hash
452 * uint32 sequence-number
455 * where the sequence-number increases from zero. As many of these
456 * hashes are used as necessary.
458 * For backwards compatibility with snapshots between 0.51 and
459 * 0.52, we also support the older key file format, which begins
460 * with "PuTTY-User-Key-File-1" (version number differs). In this
461 * format the Private-MAC: field only covers the private-plaintext
462 * field and nothing else (and without the 4-byte string length on
463 * the front too). Moreover, for RSA keys the Private-MAC: field
464 * can be replaced with a Private-Hash: field which is a plain
465 * SHA-1 hash instead of an HMAC. This is not allowable in DSA
466 * keys. (Yes, the old format was a mess. Guess why it changed :-)
469 static int read_header(FILE * fp, char *header)
476 if (c == '\n' || c == '\r' || c == EOF)
477 return 0; /* failure */
483 return 1; /* success! */
486 return 0; /* failure */
490 return 0; /* failure */
493 static char *read_body(FILE * fp)
501 text = snewn(size, char);
507 if (c == '\r' || c == '\n') {
509 if (c != '\r' && c != '\n' && c != EOF)
517 if (len + 1 > size) {
519 text = sresize(text, size, char);
526 int base64_decode_atom(char *atom, unsigned char *out)
533 for (i = 0; i < 4; i++) {
535 if (c >= 'A' && c <= 'Z')
537 else if (c >= 'a' && c <= 'z')
539 else if (c >= '0' && c <= '9')
548 return 0; /* invalid atom */
552 if (vals[0] == -1 || vals[1] == -1)
554 if (vals[2] == -1 && vals[3] != -1)
559 else if (vals[2] != -1)
564 word = ((vals[0] << 18) |
565 (vals[1] << 12) | ((vals[2] & 0x3F) << 6) | (vals[3] & 0x3F));
566 out[0] = (word >> 16) & 0xFF;
568 out[1] = (word >> 8) & 0xFF;
570 out[2] = word & 0xFF;
574 static unsigned char *read_blob(FILE * fp, int nlines, int *bloblen)
581 /* We expect at most 64 base64 characters, ie 48 real bytes, per line. */
582 blob = snewn(48 * nlines, unsigned char);
584 for (i = 0; i < nlines; i++) {
585 line = read_body(fp);
590 linelen = strlen(line);
591 if (linelen % 4 != 0 || linelen > 64) {
596 for (j = 0; j < linelen; j += 4) {
597 k = base64_decode_atom(line + j, blob + len);
612 * Magic error return value for when the passphrase is wrong.
614 struct ssh2_userkey ssh2_wrong_passphrase = {
618 const struct ssh_signkey *find_pubkey_alg(const char *name)
620 if (!strcmp(name, "ssh-rsa"))
622 else if (!strcmp(name, "ssh-dss"))
628 struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
629 char *passphrase, const char **errorstr)
632 char header[40], *b, *encryption, *comment, *mac;
633 const struct ssh_signkey *alg;
634 struct ssh2_userkey *ret;
635 int cipher, cipherblk;
636 unsigned char *public_blob, *private_blob;
637 int public_blob_len, private_blob_len;
638 int i, is_mac, old_fmt;
639 int passlen = passphrase ? strlen(passphrase) : 0;
640 const char *error = NULL;
642 ret = NULL; /* return NULL for most errors */
643 encryption = comment = mac = NULL;
644 public_blob = private_blob = NULL;
646 fp = f_open(*filename, "rb");
648 error = "can't open file";
652 /* Read the first header line which contains the key type. */
653 if (!read_header(fp, header))
655 if (0 == strcmp(header, "PuTTY-User-Key-File-2")) {
657 } else if (0 == strcmp(header, "PuTTY-User-Key-File-1")) {
658 /* this is an old key file; warn and then continue */
659 old_keyfile_warning();
662 error = "not a PuTTY SSH-2 private key";
665 error = "file format error";
666 if ((b = read_body(fp)) == NULL)
668 /* Select key algorithm structure. */
669 alg = find_pubkey_alg(b);
676 /* Read the Encryption header line. */
677 if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
679 if ((encryption = read_body(fp)) == NULL)
681 if (!strcmp(encryption, "aes256-cbc")) {
684 } else if (!strcmp(encryption, "none")) {
692 /* Read the Comment header line. */
693 if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
695 if ((comment = read_body(fp)) == NULL)
698 /* Read the Public-Lines header line and the public blob. */
699 if (!read_header(fp, header) || 0 != strcmp(header, "Public-Lines"))
701 if ((b = read_body(fp)) == NULL)
705 if ((public_blob = read_blob(fp, i, &public_blob_len)) == NULL)
708 /* Read the Private-Lines header line and the Private blob. */
709 if (!read_header(fp, header) || 0 != strcmp(header, "Private-Lines"))
711 if ((b = read_body(fp)) == NULL)
715 if ((private_blob = read_blob(fp, i, &private_blob_len)) == NULL)
718 /* Read the Private-MAC or Private-Hash header line. */
719 if (!read_header(fp, header))
721 if (0 == strcmp(header, "Private-MAC")) {
722 if ((mac = read_body(fp)) == NULL)
725 } else if (0 == strcmp(header, "Private-Hash") &&
726 alg == &ssh_rsa && old_fmt) {
727 if ((mac = read_body(fp)) == NULL)
737 * Decrypt the private blob.
740 unsigned char key[40];
745 if (private_blob_len % cipherblk)
749 SHA_Bytes(&s, "\0\0\0\0", 4);
750 SHA_Bytes(&s, passphrase, passlen);
751 SHA_Final(&s, key + 0);
753 SHA_Bytes(&s, "\0\0\0\1", 4);
754 SHA_Bytes(&s, passphrase, passlen);
755 SHA_Final(&s, key + 20);
756 aes256_decrypt_pubkey(key, private_blob, private_blob_len);
764 unsigned char binary[20];
765 unsigned char *macdata;
770 /* MAC (or hash) only covers the private blob. */
771 macdata = private_blob;
772 maclen = private_blob_len;
776 int namelen = strlen(alg->name);
777 int enclen = strlen(encryption);
778 int commlen = strlen(comment);
779 maclen = (4 + namelen +
782 4 + public_blob_len +
783 4 + private_blob_len);
784 macdata = snewn(maclen, unsigned char);
786 #define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len)
787 DO_STR(alg->name, namelen);
788 DO_STR(encryption, enclen);
789 DO_STR(comment, commlen);
790 DO_STR(public_blob, public_blob_len);
791 DO_STR(private_blob, private_blob_len);
798 unsigned char mackey[20];
799 char header[] = "putty-private-key-file-mac-key";
802 SHA_Bytes(&s, header, sizeof(header)-1);
803 if (cipher && passphrase)
804 SHA_Bytes(&s, passphrase, passlen);
805 SHA_Final(&s, mackey);
807 hmac_sha1_simple(mackey, 20, macdata, maclen, binary);
809 memset(mackey, 0, sizeof(mackey));
810 memset(&s, 0, sizeof(s));
812 SHA_Simple(macdata, maclen, binary);
816 memset(macdata, 0, maclen);
820 for (i = 0; i < 20; i++)
821 sprintf(realmac + 2 * i, "%02x", binary[i]);
823 if (strcmp(mac, realmac)) {
824 /* An incorrect MAC is an unconditional Error if the key is
825 * unencrypted. Otherwise, it means Wrong Passphrase. */
827 error = "wrong passphrase";
828 ret = SSH2_WRONG_PASSPHRASE;
830 error = "MAC failed";
839 * Create and return the key.
841 ret = snew(struct ssh2_userkey);
843 ret->comment = comment;
844 ret->data = alg->createkey(public_blob, public_blob_len,
845 private_blob, private_blob_len);
850 error = "createkey failed";
881 char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
882 int *pub_blob_len, const char **errorstr)
886 const struct ssh_signkey *alg;
887 unsigned char *public_blob;
890 const char *error = NULL;
894 fp = f_open(*filename, "rb");
896 error = "can't open file";
900 /* Read the first header line which contains the key type. */
901 if (!read_header(fp, header)
902 || (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
903 0 != strcmp(header, "PuTTY-User-Key-File-1"))) {
904 error = "not a PuTTY SSH-2 private key";
907 error = "file format error";
908 if ((b = read_body(fp)) == NULL)
910 /* Select key algorithm structure. Currently only ssh-rsa. */
911 alg = find_pubkey_alg(b);
918 /* Read the Encryption header line. */
919 if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
921 if ((b = read_body(fp)) == NULL)
923 sfree(b); /* we don't care */
925 /* Read the Comment header line. */
926 if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
928 if ((b = read_body(fp)) == NULL)
930 sfree(b); /* we don't care */
932 /* Read the Public-Lines header line and the public blob. */
933 if (!read_header(fp, header) || 0 != strcmp(header, "Public-Lines"))
935 if ((b = read_body(fp)) == NULL)
939 if ((public_blob = read_blob(fp, i, &public_blob_len)) == NULL)
944 *pub_blob_len = public_blob_len;
946 *algorithm = alg->name;
947 return (char *)public_blob;
962 int ssh2_userkey_encrypted(const Filename *filename, char **commentptr)
965 char header[40], *b, *comment;
971 fp = f_open(*filename, "rb");
974 if (!read_header(fp, header)
975 || (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
976 0 != strcmp(header, "PuTTY-User-Key-File-1"))) {
980 if ((b = read_body(fp)) == NULL) {
984 sfree(b); /* we don't care about key type here */
985 /* Read the Encryption header line. */
986 if (!read_header(fp, header) || 0 != strcmp(header, "Encryption")) {
990 if ((b = read_body(fp)) == NULL) {
995 /* Read the Comment header line. */
996 if (!read_header(fp, header) || 0 != strcmp(header, "Comment")) {
1001 if ((comment = read_body(fp)) == NULL) {
1008 *commentptr = comment;
1011 if (!strcmp(b, "aes256-cbc"))
1019 int base64_lines(int datalen)
1021 /* When encoding, we use 64 chars/line, which equals 48 real chars. */
1022 return (datalen + 47) / 48;
1025 void base64_encode(FILE * fp, unsigned char *data, int datalen, int cpl)
1031 while (datalen > 0) {
1032 n = (datalen < 3 ? datalen : 3);
1033 base64_encode_atom(data, n, out);
1036 for (i = 0; i < 4; i++) {
1037 if (linelen >= cpl) {
1048 int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key,
1052 unsigned char *pub_blob, *priv_blob, *priv_blob_encrypted;
1053 int pub_blob_len, priv_blob_len, priv_encrypted_len;
1058 unsigned char priv_mac[20];
1061 * Fetch the key component blobs.
1063 pub_blob = key->alg->public_blob(key->data, &pub_blob_len);
1064 priv_blob = key->alg->private_blob(key->data, &priv_blob_len);
1065 if (!pub_blob || !priv_blob) {
1072 * Determine encryption details, and encrypt the private blob.
1075 cipherstr = "aes256-cbc";
1081 priv_encrypted_len = priv_blob_len + cipherblk - 1;
1082 priv_encrypted_len -= priv_encrypted_len % cipherblk;
1083 priv_blob_encrypted = snewn(priv_encrypted_len, unsigned char);
1084 memset(priv_blob_encrypted, 0, priv_encrypted_len);
1085 memcpy(priv_blob_encrypted, priv_blob, priv_blob_len);
1086 /* Create padding based on the SHA hash of the unpadded blob. This prevents
1087 * too easy a known-plaintext attack on the last block. */
1088 SHA_Simple(priv_blob, priv_blob_len, priv_mac);
1089 assert(priv_encrypted_len - priv_blob_len < 20);
1090 memcpy(priv_blob_encrypted + priv_blob_len, priv_mac,
1091 priv_encrypted_len - priv_blob_len);
1093 /* Now create the MAC. */
1095 unsigned char *macdata;
1098 int namelen = strlen(key->alg->name);
1099 int enclen = strlen(cipherstr);
1100 int commlen = strlen(key->comment);
1102 unsigned char mackey[20];
1103 char header[] = "putty-private-key-file-mac-key";
1105 maclen = (4 + namelen +
1109 4 + priv_encrypted_len);
1110 macdata = snewn(maclen, unsigned char);
1112 #define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len)
1113 DO_STR(key->alg->name, namelen);
1114 DO_STR(cipherstr, enclen);
1115 DO_STR(key->comment, commlen);
1116 DO_STR(pub_blob, pub_blob_len);
1117 DO_STR(priv_blob_encrypted, priv_encrypted_len);
1120 SHA_Bytes(&s, header, sizeof(header)-1);
1122 SHA_Bytes(&s, passphrase, strlen(passphrase));
1123 SHA_Final(&s, mackey);
1124 hmac_sha1_simple(mackey, 20, macdata, maclen, priv_mac);
1125 memset(macdata, 0, maclen);
1127 memset(mackey, 0, sizeof(mackey));
1128 memset(&s, 0, sizeof(s));
1132 unsigned char key[40];
1135 passlen = strlen(passphrase);
1138 SHA_Bytes(&s, "\0\0\0\0", 4);
1139 SHA_Bytes(&s, passphrase, passlen);
1140 SHA_Final(&s, key + 0);
1142 SHA_Bytes(&s, "\0\0\0\1", 4);
1143 SHA_Bytes(&s, passphrase, passlen);
1144 SHA_Final(&s, key + 20);
1145 aes256_encrypt_pubkey(key, priv_blob_encrypted,
1146 priv_encrypted_len);
1148 memset(key, 0, sizeof(key));
1149 memset(&s, 0, sizeof(s));
1152 fp = f_open(*filename, "w");
1155 fprintf(fp, "PuTTY-User-Key-File-2: %s\n", key->alg->name);
1156 fprintf(fp, "Encryption: %s\n", cipherstr);
1157 fprintf(fp, "Comment: %s\n", key->comment);
1158 fprintf(fp, "Public-Lines: %d\n", base64_lines(pub_blob_len));
1159 base64_encode(fp, pub_blob, pub_blob_len, 64);
1160 fprintf(fp, "Private-Lines: %d\n", base64_lines(priv_encrypted_len));
1161 base64_encode(fp, priv_blob_encrypted, priv_encrypted_len, 64);
1162 fprintf(fp, "Private-MAC: ");
1163 for (i = 0; i < 20; i++)
1164 fprintf(fp, "%02x", priv_mac[i]);
1169 memset(priv_blob, 0, priv_blob_len);
1171 sfree(priv_blob_encrypted);
1175 /* ----------------------------------------------------------------------
1176 * A function to determine the type of a private key file. Returns
1177 * 0 on failure, 1 or 2 on success.
1179 int key_type(const Filename *filename)
1183 const char putty2_sig[] = "PuTTY-User-Key-File-";
1184 const char sshcom_sig[] = "---- BEGIN SSH2 ENCRYPTED PRIVAT";
1185 const char openssh_sig[] = "-----BEGIN ";
1188 fp = f_open(*filename, "r");
1190 return SSH_KEYTYPE_UNOPENABLE;
1191 i = fread(buf, 1, sizeof(buf), fp);
1194 return SSH_KEYTYPE_UNOPENABLE;
1196 return SSH_KEYTYPE_UNKNOWN;
1197 if (!memcmp(buf, rsa_signature, sizeof(rsa_signature)-1))
1198 return SSH_KEYTYPE_SSH1;
1199 if (!memcmp(buf, putty2_sig, sizeof(putty2_sig)-1))
1200 return SSH_KEYTYPE_SSH2;
1201 if (!memcmp(buf, openssh_sig, sizeof(openssh_sig)-1))
1202 return SSH_KEYTYPE_OPENSSH;
1203 if (!memcmp(buf, sshcom_sig, sizeof(sshcom_sig)-1))
1204 return SSH_KEYTYPE_SSHCOM;
1205 return SSH_KEYTYPE_UNKNOWN; /* unrecognised or EOF */
1209 * Convert the type word to a string, for `wrong type' error
1212 char *key_type_to_str(int type)
1215 case SSH_KEYTYPE_UNOPENABLE: return "unable to open file"; break;
1216 case SSH_KEYTYPE_UNKNOWN: return "not a private key"; break;
1217 case SSH_KEYTYPE_SSH1: return "SSH1 private key"; break;
1218 case SSH_KEYTYPE_SSH2: return "PuTTY SSH2 private key"; break;
1219 case SSH_KEYTYPE_OPENSSH: return "OpenSSH SSH2 private key"; break;
1220 case SSH_KEYTYPE_SSHCOM: return "ssh.com SSH2 private key"; break;
1221 default: return "INTERNAL ERROR"; break;