2 * Generic SSH public-key handling operations. In particular,
3 * reading of SSH public-key files, and also the generic `sign'
4 * operation for SSH-2 (which checks the type of the key and
5 * dispatches to the appropriate key-type specific function).
16 #define rsa_signature "SSH PRIVATE KEY FILE FORMAT 1.1\n"
18 #define BASE64_TOINT(x) ( (x)-'A'<26 ? (x)-'A'+0 :\
19 (x)-'a'<26 ? (x)-'a'+26 :\
20 (x)-'0'<10 ? (x)-'0'+52 :\
24 static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only,
25 char **commentptr, char *passphrase,
28 unsigned char buf[16384];
29 unsigned char keybuf[16];
33 struct MD5Context md5c;
38 /* Slurp the whole file (minus the header) into a buffer. */
39 len = fread(buf, 1, sizeof(buf), fp);
41 if (len < 0 || len == sizeof(buf)) {
42 *error = "error reading file";
43 goto end; /* file too big or not read */
47 *error = "file format error";
50 * A zero byte. (The signature includes a terminating NUL.)
52 if (len - i < 1 || buf[i] != 0)
56 /* One byte giving encryption type, and one reserved uint32. */
60 if (ciphertype != 0 && ciphertype != SSH_CIPHER_3DES)
64 goto end; /* reserved field not present */
65 if (buf[i] != 0 || buf[i + 1] != 0 || buf[i + 2] != 0
66 || buf[i + 3] != 0) goto end; /* reserved field nonzero, panic! */
69 /* Now the serious stuff. An ordinary SSH-1 public key. */
70 j = makekey(buf + i, len, key, NULL, 1);
72 goto end; /* overran */
75 /* Next, the comment field. */
76 j = toint(GET_32BIT(buf + i));
78 if (j < 0 || len - i < j)
80 comment = snewn(j + 1, char);
82 memcpy(comment, buf + i, j);
87 *commentptr = dupstr(comment);
89 key->comment = comment;
99 ret = ciphertype != 0;
105 * Decrypt remainder of buffer.
109 MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
110 MD5Final(keybuf, &md5c);
111 des3_decrypt_pubkey(keybuf, buf + i, (len - i + 7) & ~7);
112 smemclr(keybuf, sizeof(keybuf)); /* burn the evidence */
116 * We are now in the secret part of the key. The first four
117 * bytes should be of the form a, b, a, b.
121 if (buf[i] != buf[i + 2] || buf[i + 1] != buf[i + 3]) {
122 *error = "wrong passphrase";
129 * After that, we have one further bignum which is our
130 * decryption exponent, and then the three auxiliary values
133 j = makeprivate(buf + i, len - i, key);
136 j = ssh1_read_bignum(buf + i, len - i, &key->iqmp);
139 j = ssh1_read_bignum(buf + i, len - i, &key->q);
142 j = ssh1_read_bignum(buf + i, len - i, &key->p);
146 if (!rsa_verify(key)) {
147 *error = "rsa_verify failed";
154 smemclr(buf, sizeof(buf)); /* burn the evidence */
158 int loadrsakey(const Filename *filename, struct RSAKey *key, char *passphrase,
159 const char **errorstr)
164 const char *error = NULL;
166 fp = f_open(filename, "rb", FALSE);
168 error = "can't open file";
173 * Read the first line of the file and see if it's a v1 private
176 if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
178 * This routine will take care of calling fclose() for us.
180 ret = loadrsakey_main(fp, key, FALSE, NULL, passphrase, &error);
186 * Otherwise, we have nothing. Return empty-handed.
188 error = "not an SSH-1 RSA file";
193 if ((ret != 1) && errorstr)
199 * See whether an RSA key is encrypted. Return its comment field as
202 int rsakey_encrypted(const Filename *filename, char **comment)
207 fp = f_open(filename, "rb", FALSE);
209 return 0; /* doesn't even exist */
212 * Read the first line of the file and see if it's a v1 private
215 if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
218 * This routine will take care of calling fclose() for us.
220 return loadrsakey_main(fp, NULL, FALSE, comment, NULL, &dummy);
223 return 0; /* wasn't the right kind of file */
227 * Return a malloc'ed chunk of memory containing the public blob of
228 * an RSA key, as given in the agent protocol (modulus bits,
229 * exponent, modulus).
231 int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
232 char **commentptr, const char **errorstr)
238 const char *error = NULL;
240 /* Default return if we fail. */
245 fp = f_open(filename, "rb", FALSE);
247 error = "can't open file";
252 * Read the first line of the file and see if it's a v1 private
255 if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
256 memset(&key, 0, sizeof(key));
257 if (loadrsakey_main(fp, &key, TRUE, commentptr, NULL, &error)) {
258 *blob = rsa_public_blob(&key, bloblen);
262 fp = NULL; /* loadrsakey_main unconditionally closes fp */
264 error = "not an SSH-1 RSA file";
270 if ((ret != 1) && errorstr)
276 * Save an RSA key file. Return nonzero on success.
278 int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase)
280 unsigned char buf[16384];
281 unsigned char keybuf[16];
282 struct MD5Context md5c;
283 unsigned char *p, *estart;
287 * Write the initial signature.
290 memcpy(p, rsa_signature, sizeof(rsa_signature));
291 p += sizeof(rsa_signature);
294 * One byte giving encryption type, and one reserved (zero)
297 *p++ = (passphrase ? SSH_CIPHER_3DES : 0);
302 * An ordinary SSH-1 public key consists of: a uint32
303 * containing the bit count, then two bignums containing the
304 * modulus and exponent respectively.
306 PUT_32BIT(p, bignum_bitcount(key->modulus));
308 p += ssh1_write_bignum(p, key->modulus);
309 p += ssh1_write_bignum(p, key->exponent);
312 * A string containing the comment field.
315 PUT_32BIT(p, strlen(key->comment));
317 memcpy(p, key->comment, strlen(key->comment));
318 p += strlen(key->comment);
325 * The encrypted portion starts here.
330 * Two bytes, then the same two bytes repeated.
332 *p++ = random_byte();
333 *p++ = random_byte();
339 * Four more bignums: the decryption exponent, then iqmp, then
342 p += ssh1_write_bignum(p, key->private_exponent);
343 p += ssh1_write_bignum(p, key->iqmp);
344 p += ssh1_write_bignum(p, key->q);
345 p += ssh1_write_bignum(p, key->p);
348 * Now write zeros until the encrypted portion is a multiple of
351 while ((p - estart) % 8)
355 * Now encrypt the encrypted portion.
359 MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
360 MD5Final(keybuf, &md5c);
361 des3_encrypt_pubkey(keybuf, estart, p - estart);
362 smemclr(keybuf, sizeof(keybuf)); /* burn the evidence */
366 * Done. Write the result to the file.
368 fp = f_open(filename, "wb", TRUE);
370 int ret = (fwrite(buf, 1, p - buf, fp) == (size_t) (p - buf));
378 /* ----------------------------------------------------------------------
379 * SSH-2 private key load/store functions.
383 * PuTTY's own format for SSH-2 keys is as follows:
385 * The file is text. Lines are terminated by CRLF, although CR-only
386 * and LF-only are tolerated on input.
388 * The first line says "PuTTY-User-Key-File-2: " plus the name of the
389 * algorithm ("ssh-dss", "ssh-rsa" etc).
391 * The next line says "Encryption: " plus an encryption type.
392 * Currently the only supported encryption types are "aes256-cbc"
395 * The next line says "Comment: " plus the comment string.
397 * Next there is a line saying "Public-Lines: " plus a number N.
398 * The following N lines contain a base64 encoding of the public
399 * part of the key. This is encoded as the standard SSH-2 public key
400 * blob (with no initial length): so for RSA, for example, it will
407 * Next, there is a line saying "Private-Lines: " plus a number N,
408 * and then N lines containing the (potentially encrypted) private
409 * part of the key. For the key type "ssh-rsa", this will be
412 * mpint private_exponent
413 * mpint p (the larger of the two primes)
414 * mpint q (the smaller prime)
415 * mpint iqmp (the inverse of q modulo p)
416 * data padding (to reach a multiple of the cipher block size)
418 * And for "ssh-dss", it will be composed of
420 * mpint x (the private key parameter)
421 * [ string hash 20-byte hash of mpints p || q || g only in old format ]
423 * Finally, there is a line saying "Private-MAC: " plus a hex
424 * representation of a HMAC-SHA-1 of:
426 * string name of algorithm ("ssh-dss", "ssh-rsa")
427 * string encryption type
430 * string private-plaintext (the plaintext version of the
431 * private part, including the final
434 * The key to the MAC is itself a SHA-1 hash of:
436 * data "putty-private-key-file-mac-key"
439 * (An empty passphrase is used for unencrypted keys.)
441 * If the key is encrypted, the encryption key is derived from the
442 * passphrase by means of a succession of SHA-1 hashes. Each hash
445 * uint32 sequence-number
448 * where the sequence-number increases from zero. As many of these
449 * hashes are used as necessary.
451 * For backwards compatibility with snapshots between 0.51 and
452 * 0.52, we also support the older key file format, which begins
453 * with "PuTTY-User-Key-File-1" (version number differs). In this
454 * format the Private-MAC: field only covers the private-plaintext
455 * field and nothing else (and without the 4-byte string length on
456 * the front too). Moreover, the Private-MAC: field can be replaced
457 * with a Private-Hash: field which is a plain SHA-1 hash instead of
458 * an HMAC (this was generated for unencrypted keys).
461 static int read_header(FILE * fp, char *header)
468 if (c == '\n' || c == '\r' || c == EOF)
469 return 0; /* failure */
475 return 1; /* success! */
478 return 0; /* failure */
482 return 0; /* failure */
485 static char *read_body(FILE * fp)
493 text = snewn(size, char);
499 if (c == '\r' || c == '\n' || c == EOF) {
502 if (c != '\r' && c != '\n')
507 if (len + 1 >= size) {
509 text = sresize(text, size, char);
516 static unsigned char *read_blob(FILE * fp, int nlines, int *bloblen)
523 /* We expect at most 64 base64 characters, ie 48 real bytes, per line. */
524 blob = snewn(48 * nlines, unsigned char);
526 for (i = 0; i < nlines; i++) {
527 line = read_body(fp);
532 linelen = strlen(line);
533 if (linelen % 4 != 0 || linelen > 64) {
538 for (j = 0; j < linelen; j += 4) {
539 k = base64_decode_atom(line + j, blob + len);
554 * Magic error return value for when the passphrase is wrong.
556 struct ssh2_userkey ssh2_wrong_passphrase = {
560 const struct ssh_signkey *find_pubkey_alg(const char *name)
562 if (!strcmp(name, "ssh-rsa"))
564 else if (!strcmp(name, "ssh-dss"))
570 struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
571 char *passphrase, const char **errorstr)
574 char header[40], *b, *encryption, *comment, *mac;
575 const struct ssh_signkey *alg;
576 struct ssh2_userkey *ret;
577 int cipher, cipherblk;
578 unsigned char *public_blob, *private_blob;
579 int public_blob_len, private_blob_len;
580 int i, is_mac, old_fmt;
581 int passlen = passphrase ? strlen(passphrase) : 0;
582 const char *error = NULL;
584 ret = NULL; /* return NULL for most errors */
585 encryption = comment = mac = NULL;
586 public_blob = private_blob = NULL;
588 fp = f_open(filename, "rb", FALSE);
590 error = "can't open file";
594 /* Read the first header line which contains the key type. */
595 if (!read_header(fp, header))
597 if (0 == strcmp(header, "PuTTY-User-Key-File-2")) {
599 } else if (0 == strcmp(header, "PuTTY-User-Key-File-1")) {
600 /* this is an old key file; warn and then continue */
601 old_keyfile_warning();
603 } else if (0 == strncmp(header, "PuTTY-User-Key-File-", 20)) {
604 /* this is a key file FROM THE FUTURE; refuse it, but with a
605 * more specific error message than the generic one below */
606 error = "PuTTY key format too new";
609 error = "not a PuTTY SSH-2 private key";
612 error = "file format error";
613 if ((b = read_body(fp)) == NULL)
615 /* Select key algorithm structure. */
616 alg = find_pubkey_alg(b);
623 /* Read the Encryption header line. */
624 if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
626 if ((encryption = read_body(fp)) == NULL)
628 if (!strcmp(encryption, "aes256-cbc")) {
631 } else if (!strcmp(encryption, "none")) {
638 /* Read the Comment header line. */
639 if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
641 if ((comment = read_body(fp)) == NULL)
644 /* Read the Public-Lines header line and the public blob. */
645 if (!read_header(fp, header) || 0 != strcmp(header, "Public-Lines"))
647 if ((b = read_body(fp)) == NULL)
651 if ((public_blob = read_blob(fp, i, &public_blob_len)) == NULL)
654 /* Read the Private-Lines header line and the Private blob. */
655 if (!read_header(fp, header) || 0 != strcmp(header, "Private-Lines"))
657 if ((b = read_body(fp)) == NULL)
661 if ((private_blob = read_blob(fp, i, &private_blob_len)) == NULL)
664 /* Read the Private-MAC or Private-Hash header line. */
665 if (!read_header(fp, header))
667 if (0 == strcmp(header, "Private-MAC")) {
668 if ((mac = read_body(fp)) == NULL)
671 } else if (0 == strcmp(header, "Private-Hash") && old_fmt) {
672 if ((mac = read_body(fp)) == NULL)
682 * Decrypt the private blob.
685 unsigned char key[40];
690 if (private_blob_len % cipherblk)
694 SHA_Bytes(&s, "\0\0\0\0", 4);
695 SHA_Bytes(&s, passphrase, passlen);
696 SHA_Final(&s, key + 0);
698 SHA_Bytes(&s, "\0\0\0\1", 4);
699 SHA_Bytes(&s, passphrase, passlen);
700 SHA_Final(&s, key + 20);
701 aes256_decrypt_pubkey(key, private_blob, private_blob_len);
709 unsigned char binary[20];
710 unsigned char *macdata;
715 /* MAC (or hash) only covers the private blob. */
716 macdata = private_blob;
717 maclen = private_blob_len;
721 int namelen = strlen(alg->name);
722 int enclen = strlen(encryption);
723 int commlen = strlen(comment);
724 maclen = (4 + namelen +
727 4 + public_blob_len +
728 4 + private_blob_len);
729 macdata = snewn(maclen, unsigned char);
731 #define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len)
732 DO_STR(alg->name, namelen);
733 DO_STR(encryption, enclen);
734 DO_STR(comment, commlen);
735 DO_STR(public_blob, public_blob_len);
736 DO_STR(private_blob, private_blob_len);
743 unsigned char mackey[20];
744 char header[] = "putty-private-key-file-mac-key";
747 SHA_Bytes(&s, header, sizeof(header)-1);
748 if (cipher && passphrase)
749 SHA_Bytes(&s, passphrase, passlen);
750 SHA_Final(&s, mackey);
752 hmac_sha1_simple(mackey, 20, macdata, maclen, binary);
754 smemclr(mackey, sizeof(mackey));
755 smemclr(&s, sizeof(s));
757 SHA_Simple(macdata, maclen, binary);
761 smemclr(macdata, maclen);
765 for (i = 0; i < 20; i++)
766 sprintf(realmac + 2 * i, "%02x", binary[i]);
768 if (strcmp(mac, realmac)) {
769 /* An incorrect MAC is an unconditional Error if the key is
770 * unencrypted. Otherwise, it means Wrong Passphrase. */
772 error = "wrong passphrase";
773 ret = SSH2_WRONG_PASSPHRASE;
775 error = "MAC failed";
785 * Create and return the key.
787 ret = snew(struct ssh2_userkey);
789 ret->comment = comment;
790 ret->data = alg->createkey(public_blob, public_blob_len,
791 private_blob, private_blob_len);
795 error = "createkey failed";
826 unsigned char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
827 int *pub_blob_len, char **commentptr,
828 const char **errorstr)
832 const struct ssh_signkey *alg;
833 unsigned char *public_blob;
836 const char *error = NULL;
841 fp = f_open(filename, "rb", FALSE);
843 error = "can't open file";
847 /* Read the first header line which contains the key type. */
848 if (!read_header(fp, header)
849 || (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
850 0 != strcmp(header, "PuTTY-User-Key-File-1"))) {
851 if (0 == strncmp(header, "PuTTY-User-Key-File-", 20))
852 error = "PuTTY key format too new";
854 error = "not a PuTTY SSH-2 private key";
857 error = "file format error";
858 if ((b = read_body(fp)) == NULL)
860 /* Select key algorithm structure. */
861 alg = find_pubkey_alg(b);
868 /* Read the Encryption header line. */
869 if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
871 if ((b = read_body(fp)) == NULL)
873 sfree(b); /* we don't care */
875 /* Read the Comment header line. */
876 if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
878 if ((comment = read_body(fp)) == NULL)
882 *commentptr = comment;
886 /* Read the Public-Lines header line and the public blob. */
887 if (!read_header(fp, header) || 0 != strcmp(header, "Public-Lines"))
889 if ((b = read_body(fp)) == NULL)
893 if ((public_blob = read_blob(fp, i, &public_blob_len)) == NULL)
898 *pub_blob_len = public_blob_len;
900 *algorithm = alg->name;
916 int ssh2_userkey_encrypted(const Filename *filename, char **commentptr)
919 char header[40], *b, *comment;
925 fp = f_open(filename, "rb", FALSE);
928 if (!read_header(fp, header)
929 || (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
930 0 != strcmp(header, "PuTTY-User-Key-File-1"))) {
934 if ((b = read_body(fp)) == NULL) {
938 sfree(b); /* we don't care about key type here */
939 /* Read the Encryption header line. */
940 if (!read_header(fp, header) || 0 != strcmp(header, "Encryption")) {
944 if ((b = read_body(fp)) == NULL) {
949 /* Read the Comment header line. */
950 if (!read_header(fp, header) || 0 != strcmp(header, "Comment")) {
955 if ((comment = read_body(fp)) == NULL) {
962 *commentptr = comment;
967 if (!strcmp(b, "aes256-cbc"))
975 int base64_lines(int datalen)
977 /* When encoding, we use 64 chars/line, which equals 48 real chars. */
978 return (datalen + 47) / 48;
981 void base64_encode(FILE * fp, unsigned char *data, int datalen, int cpl)
987 while (datalen > 0) {
988 n = (datalen < 3 ? datalen : 3);
989 base64_encode_atom(data, n, out);
992 for (i = 0; i < 4; i++) {
993 if (linelen >= cpl) {
1004 int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key,
1008 unsigned char *pub_blob, *priv_blob, *priv_blob_encrypted;
1009 int pub_blob_len, priv_blob_len, priv_encrypted_len;
1014 unsigned char priv_mac[20];
1017 * Fetch the key component blobs.
1019 pub_blob = key->alg->public_blob(key->data, &pub_blob_len);
1020 priv_blob = key->alg->private_blob(key->data, &priv_blob_len);
1021 if (!pub_blob || !priv_blob) {
1028 * Determine encryption details, and encrypt the private blob.
1031 cipherstr = "aes256-cbc";
1037 priv_encrypted_len = priv_blob_len + cipherblk - 1;
1038 priv_encrypted_len -= priv_encrypted_len % cipherblk;
1039 priv_blob_encrypted = snewn(priv_encrypted_len, unsigned char);
1040 memset(priv_blob_encrypted, 0, priv_encrypted_len);
1041 memcpy(priv_blob_encrypted, priv_blob, priv_blob_len);
1042 /* Create padding based on the SHA hash of the unpadded blob. This prevents
1043 * too easy a known-plaintext attack on the last block. */
1044 SHA_Simple(priv_blob, priv_blob_len, priv_mac);
1045 assert(priv_encrypted_len - priv_blob_len < 20);
1046 memcpy(priv_blob_encrypted + priv_blob_len, priv_mac,
1047 priv_encrypted_len - priv_blob_len);
1049 /* Now create the MAC. */
1051 unsigned char *macdata;
1054 int namelen = strlen(key->alg->name);
1055 int enclen = strlen(cipherstr);
1056 int commlen = strlen(key->comment);
1058 unsigned char mackey[20];
1059 char header[] = "putty-private-key-file-mac-key";
1061 maclen = (4 + namelen +
1065 4 + priv_encrypted_len);
1066 macdata = snewn(maclen, unsigned char);
1068 #define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len)
1069 DO_STR(key->alg->name, namelen);
1070 DO_STR(cipherstr, enclen);
1071 DO_STR(key->comment, commlen);
1072 DO_STR(pub_blob, pub_blob_len);
1073 DO_STR(priv_blob_encrypted, priv_encrypted_len);
1076 SHA_Bytes(&s, header, sizeof(header)-1);
1078 SHA_Bytes(&s, passphrase, strlen(passphrase));
1079 SHA_Final(&s, mackey);
1080 hmac_sha1_simple(mackey, 20, macdata, maclen, priv_mac);
1081 smemclr(macdata, maclen);
1083 smemclr(mackey, sizeof(mackey));
1084 smemclr(&s, sizeof(s));
1088 unsigned char key[40];
1091 passlen = strlen(passphrase);
1094 SHA_Bytes(&s, "\0\0\0\0", 4);
1095 SHA_Bytes(&s, passphrase, passlen);
1096 SHA_Final(&s, key + 0);
1098 SHA_Bytes(&s, "\0\0\0\1", 4);
1099 SHA_Bytes(&s, passphrase, passlen);
1100 SHA_Final(&s, key + 20);
1101 aes256_encrypt_pubkey(key, priv_blob_encrypted,
1102 priv_encrypted_len);
1104 smemclr(key, sizeof(key));
1105 smemclr(&s, sizeof(s));
1108 fp = f_open(filename, "w", TRUE);
1111 fprintf(fp, "PuTTY-User-Key-File-2: %s\n", key->alg->name);
1112 fprintf(fp, "Encryption: %s\n", cipherstr);
1113 fprintf(fp, "Comment: %s\n", key->comment);
1114 fprintf(fp, "Public-Lines: %d\n", base64_lines(pub_blob_len));
1115 base64_encode(fp, pub_blob, pub_blob_len, 64);
1116 fprintf(fp, "Private-Lines: %d\n", base64_lines(priv_encrypted_len));
1117 base64_encode(fp, priv_blob_encrypted, priv_encrypted_len, 64);
1118 fprintf(fp, "Private-MAC: ");
1119 for (i = 0; i < 20; i++)
1120 fprintf(fp, "%02x", priv_mac[i]);
1125 smemclr(priv_blob, priv_blob_len);
1127 sfree(priv_blob_encrypted);
1131 /* ----------------------------------------------------------------------
1132 * A function to determine the type of a private key file. Returns
1133 * 0 on failure, 1 or 2 on success.
1135 int key_type(const Filename *filename)
1139 const char putty2_sig[] = "PuTTY-User-Key-File-";
1140 const char sshcom_sig[] = "---- BEGIN SSH2 ENCRYPTED PRIVAT";
1141 const char openssh_sig[] = "-----BEGIN ";
1144 fp = f_open(filename, "r", FALSE);
1146 return SSH_KEYTYPE_UNOPENABLE;
1147 i = fread(buf, 1, sizeof(buf), fp);
1150 return SSH_KEYTYPE_UNOPENABLE;
1152 return SSH_KEYTYPE_UNKNOWN;
1153 if (!memcmp(buf, rsa_signature, sizeof(rsa_signature)-1))
1154 return SSH_KEYTYPE_SSH1;
1155 if (!memcmp(buf, putty2_sig, sizeof(putty2_sig)-1))
1156 return SSH_KEYTYPE_SSH2;
1157 if (!memcmp(buf, openssh_sig, sizeof(openssh_sig)-1))
1158 return SSH_KEYTYPE_OPENSSH;
1159 if (!memcmp(buf, sshcom_sig, sizeof(sshcom_sig)-1))
1160 return SSH_KEYTYPE_SSHCOM;
1161 return SSH_KEYTYPE_UNKNOWN; /* unrecognised or EOF */
1165 * Convert the type word to a string, for `wrong type' error
1168 char *key_type_to_str(int type)
1171 case SSH_KEYTYPE_UNOPENABLE: return "unable to open file"; break;
1172 case SSH_KEYTYPE_UNKNOWN: return "not a private key"; break;
1173 case SSH_KEYTYPE_SSH1: return "SSH-1 private key"; break;
1174 case SSH_KEYTYPE_SSH2: return "PuTTY SSH-2 private key"; break;
1175 case SSH_KEYTYPE_OPENSSH: return "OpenSSH SSH-2 private key"; break;
1176 case SSH_KEYTYPE_SSHCOM: return "ssh.com SSH-2 private key"; break;
1177 default: return "INTERNAL ERROR"; break;