2 * Code for PuTTY to import and export private key files in other
3 * SSH clients' formats.
14 #define PUT_32BIT(cp, value) do { \
16 (cp)[2] = (value) >> 8; \
17 (cp)[1] = (value) >> 16; \
18 (cp)[0] = (value) >> 24; } while (0)
20 #define GET_32BIT(cp) \
21 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
22 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
23 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
24 ((unsigned long)(unsigned char)(cp)[3]))
26 int openssh_encrypted(char *filename);
27 struct ssh2_userkey *openssh_read(char *filename, char *passphrase);
29 int sshcom_encrypted(char *filename, char **comment);
30 struct ssh2_userkey *sshcom_read(char *filename, char *passphrase);
33 * Given a key type, determine whether we know how to import it.
35 int import_possible(int type)
37 if (type == SSH_KEYTYPE_OPENSSH)
39 if (type == SSH_KEYTYPE_SSHCOM)
45 * Given a key type, determine what native key type
46 * (SSH_KEYTYPE_SSH1 or SSH_KEYTYPE_SSH2) it will come out as once
49 int import_target_type(int type)
52 * There are no known foreign SSH1 key formats.
54 return SSH_KEYTYPE_SSH2;
58 * Determine whether a foreign key is encrypted.
60 int import_encrypted(char *filename, int type, char **comment)
62 if (type == SSH_KEYTYPE_OPENSSH) {
63 *comment = filename; /* OpenSSH doesn't do key comments */
64 return openssh_encrypted(filename);
66 if (type == SSH_KEYTYPE_SSHCOM) {
67 return sshcom_encrypted(filename, comment);
75 int import_ssh1(char *filename, int type, struct RSAKey *key, char *passphrase)
83 struct ssh2_userkey *import_ssh2(char *filename, int type, char *passphrase)
85 if (type == SSH_KEYTYPE_OPENSSH)
86 return openssh_read(filename, passphrase);
87 if (type == SSH_KEYTYPE_SSHCOM)
88 return sshcom_read(filename, passphrase);
92 /* ----------------------------------------------------------------------
93 * Helper routines. (The base64 ones are defined in sshpubk.c.)
96 #define isbase64(c) ( ((c) >= 'A' && (c) <= 'Z') || \
97 ((c) >= 'a' && (c) <= 'z') || \
98 ((c) >= '0' && (c) <= '9') || \
99 (c) == '+' || (c) == '/' || (c) == '=' \
102 extern int base64_decode_atom(char *atom, unsigned char *out);
103 extern int base64_lines(int datalen);
104 extern void base64_encode_atom(unsigned char *data, int n, char *out);
105 extern void base64_encode(FILE * fp, unsigned char *data, int datalen);
108 * Read an ASN.1/BER identifier and length pair.
110 * Flags are a combination of the #defines listed below.
112 * Returns -1 if unsuccessful; otherwise returns the number of
113 * bytes used out of the source data.
116 /* ASN.1 tag classes. */
117 #define ASN1_CLASS_UNIVERSAL (0 << 6)
118 #define ASN1_CLASS_APPLICATION (1 << 6)
119 #define ASN1_CLASS_CONTEXT_SPECIFIC (2 << 6)
120 #define ASN1_CLASS_PRIVATE (3 << 6)
121 #define ASN1_CLASS_MASK (3 << 6)
123 /* Primitive versus constructed bit. */
124 #define ASN1_CONSTRUCTED (1 << 5)
126 int ber_read_id_len(void *source, int sourcelen,
127 int *id, int *length, int *flags)
129 unsigned char *p = (unsigned char *) source;
134 *flags = (*p & 0xE0);
135 if ((*p & 0x1F) == 0x1F) {
138 *id = (*id << 7) | (*p & 0x7F);
143 *id = (*id << 7) | (*p & 0x7F);
160 *length = (*length << 8) | (*p++);
167 return p - (unsigned char *) source;
170 static int put_string(void *target, void *data, int len)
172 unsigned char *d = (unsigned char *)target;
175 memcpy(d+4, data, len);
179 static int put_mp(void *target, void *data, int len)
181 unsigned char *d = (unsigned char *)target;
182 unsigned char *i = (unsigned char *)data;
187 memcpy(d+5, data, len);
191 memcpy(d+4, data, len);
196 /* ----------------------------------------------------------------------
197 * Code to read OpenSSH private keys.
200 enum { OSSH_DSA, OSSH_RSA };
205 unsigned char *keyblob;
206 int keyblob_len, keyblob_size;
209 struct openssh_key *load_openssh_key(char *filename)
211 struct openssh_key *ret;
217 int base64_chars = 0;
219 ret = smalloc(sizeof(*ret));
221 ret->keyblob_len = ret->keyblob_size = 0;
223 memset(ret->iv, 0, sizeof(ret->iv));
225 fp = fopen(filename, "r");
227 errmsg = "Unable to open key file";
230 if (!fgets(buffer, sizeof(buffer), fp) ||
231 0 != strncmp(buffer, "-----BEGIN ", 11) ||
232 0 != strcmp(buffer+strlen(buffer)-17, "PRIVATE KEY-----\n")) {
233 errmsg = "File does not begin with OpenSSH key header";
236 if (!strcmp(buffer, "-----BEGIN RSA PRIVATE KEY-----\n"))
237 ret->type = OSSH_RSA;
238 else if (!strcmp(buffer, "-----BEGIN DSA PRIVATE KEY-----\n"))
239 ret->type = OSSH_DSA;
241 errmsg = "Unrecognised key type";
247 if (!fgets(buffer, sizeof(buffer), fp)) {
248 errmsg = "Unexpected end of file";
251 if (0 == strncmp(buffer, "-----END ", 9) &&
252 0 == strcmp(buffer+strlen(buffer)-17, "PRIVATE KEY-----\n"))
254 if ((p = strchr(buffer, ':')) != NULL) {
256 errmsg = "Header found in body of key data";
260 while (*p && isspace((unsigned char)*p)) p++;
261 if (!strcmp(buffer, "Proc-Type")) {
262 if (p[0] != '4' || p[1] != ',') {
263 errmsg = "Proc-Type is not 4 (only 4 is supported)";
267 if (!strcmp(p, "ENCRYPTED\n"))
269 } else if (!strcmp(buffer, "DEK-Info")) {
272 if (strncmp(p, "DES-EDE3-CBC,", 13)) {
273 errmsg = "Ciphers other than DES-EDE3-CBC not supported";
277 for (i = 0; i < 8; i++) {
278 if (1 != sscanf(p, "%2x", &j))
284 errmsg = "Expected 16-digit iv in DEK-Info";
292 while (isbase64(*p)) {
293 base64_bit[base64_chars++] = *p;
294 if (base64_chars == 4) {
295 unsigned char out[3];
300 len = base64_decode_atom(base64_bit, out);
303 errmsg = "Invalid base64 encoding";
307 if (ret->keyblob_len + len > ret->keyblob_size) {
308 ret->keyblob_size = ret->keyblob_len + len + 256;
309 ret->keyblob = srealloc(ret->keyblob, ret->keyblob_size);
312 memcpy(ret->keyblob + ret->keyblob_len, out, len);
313 ret->keyblob_len += len;
315 memset(out, 0, sizeof(out));
323 if (ret->keyblob_len == 0 || !ret->keyblob) {
324 errmsg = "Key body not present";
328 if (ret->encrypted && ret->keyblob_len % 8 != 0) {
329 errmsg = "Encrypted key blob is not a multiple of cipher block size";
333 memset(buffer, 0, sizeof(buffer));
334 memset(base64_bit, 0, sizeof(base64_bit));
338 memset(buffer, 0, sizeof(buffer));
339 memset(base64_bit, 0, sizeof(base64_bit));
342 memset(ret->keyblob, 0, ret->keyblob_size);
345 memset(&ret, 0, sizeof(ret));
351 int openssh_encrypted(char *filename)
353 struct openssh_key *key = load_openssh_key(filename);
358 ret = key->encrypted;
359 memset(key->keyblob, 0, key->keyblob_size);
361 memset(&key, 0, sizeof(key));
366 struct ssh2_userkey *openssh_read(char *filename, char *passphrase)
368 struct openssh_key *key = load_openssh_key(filename);
369 struct ssh2_userkey *retkey;
371 int ret, id, len, flags;
373 struct ssh2_userkey *retval = NULL;
376 int blobsize, blobptr, privptr;
383 if (key->encrypted) {
385 * Derive encryption key from passphrase and iv/salt:
387 * - let block A equal MD5(passphrase || iv)
388 * - let block B equal MD5(A || passphrase || iv)
389 * - block C would be MD5(B || passphrase || iv) and so on
390 * - encryption key is the first N bytes of A || B
392 struct MD5Context md5c;
393 unsigned char keybuf[32];
396 MD5Update(&md5c, passphrase, strlen(passphrase));
397 MD5Update(&md5c, key->iv, 8);
398 MD5Final(keybuf, &md5c);
401 MD5Update(&md5c, keybuf, 16);
402 MD5Update(&md5c, passphrase, strlen(passphrase));
403 MD5Update(&md5c, key->iv, 8);
404 MD5Final(keybuf+16, &md5c);
407 * Now decrypt the key blob.
409 des3_decrypt_pubkey_ossh(keybuf, key->iv,
410 key->keyblob, key->keyblob_len);
412 memset(&md5c, 0, sizeof(md5c));
413 memset(keybuf, 0, sizeof(keybuf));
417 * Now we have a decrypted key blob, which contains an ASN.1
418 * encoded private key. We must now untangle the ASN.1.
420 * We expect the whole key blob to be formatted as a SEQUENCE
421 * (0x30 followed by a length code indicating that the rest of
422 * the blob is part of the sequence). Within that SEQUENCE we
423 * expect to see a bunch of INTEGERs. What those integers mean
424 * depends on the key type:
426 * - For RSA, we expect the integers to be 0, n, e, d, p, q,
427 * dmp1, dmq1, iqmp in that order. (The last three are d mod
428 * (p-1), d mod (q-1), inverse of q mod p respectively.)
430 * - For DSA, we expect them to be 0, p, q, g, y, x in that
436 /* Expect the SEQUENCE header. Take its absence as a failure to decrypt. */
437 ret = ber_read_id_len(p, key->keyblob_len, &id, &len, &flags);
439 if (ret < 0 || id != 16) {
440 errmsg = "ASN.1 decoding failure";
441 retval = SSH2_WRONG_PASSPHRASE;
445 /* Expect a load of INTEGERs. */
446 if (key->type == OSSH_RSA)
448 else if (key->type == OSSH_DSA)
452 * Space to create key blob in.
454 blobsize = 256+key->keyblob_len;
455 blob = smalloc(blobsize);
457 if (key->type == OSSH_DSA)
458 memcpy(blob+4, "ssh-dss", 7);
459 else if (key->type == OSSH_RSA)
460 memcpy(blob+4, "ssh-rsa", 7);
464 for (i = 0; i < num_integers; i++) {
465 ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
468 if (ret < 0 || id != 2 ||
469 key->keyblob+key->keyblob_len-p < len) {
470 errmsg = "ASN.1 decoding failure";
476 * The first integer should be zero always (I think
477 * this is some sort of version indication).
479 if (len != 1 || p[0] != 0) {
480 errmsg = "Version number mismatch";
483 } else if (key->type == OSSH_RSA) {
485 * Integers 1 and 2 go into the public blob but in the
486 * opposite order; integers 3, 4, 5 and 8 go into the
487 * private blob. The other two (6 and 7) are ignored.
490 /* Save the details for after we deal with number 2. */
493 } else if (i != 6 && i != 7) {
494 PUT_32BIT(blob+blobptr, len);
495 memcpy(blob+blobptr+4, p, len);
498 PUT_32BIT(blob+blobptr, modlen);
499 memcpy(blob+blobptr+4, modptr, modlen);
504 } else if (key->type == OSSH_DSA) {
506 * Integers 1-4 go into the public blob; integer 5 goes
507 * into the private blob.
509 PUT_32BIT(blob+blobptr, len);
510 memcpy(blob+blobptr+4, p, len);
516 /* Skip past the number. */
521 * Now put together the actual key. Simplest way to do this is
522 * to assemble our own key blobs and feed them to the createkey
523 * functions; this is a bit faffy but it does mean we get all
524 * the sanity checks for free.
526 assert(privptr > 0); /* should have bombed by now if not */
527 retkey = smalloc(sizeof(struct ssh2_userkey));
528 retkey->alg = (key->type == OSSH_RSA ? &ssh_rsa : &ssh_dss);
529 retkey->data = retkey->alg->createkey(blob, privptr,
530 blob+privptr, blobptr-privptr);
533 errmsg = "unable to create key data structure";
537 retkey->comment = dupstr("imported-openssh-key");
538 errmsg = NULL; /* no error */
543 memset(blob, 0, blobsize);
546 memset(key->keyblob, 0, key->keyblob_size);
548 memset(&key, 0, sizeof(key));
553 /* ----------------------------------------------------------------------
554 * Code to read ssh.com private keys.
558 * The format of the base64 blob is largely ssh2-packet-formatted,
559 * except that mpints are a bit different: they're more like the
560 * old ssh1 mpint. You have a 32-bit bit count N, followed by
561 * (N+7)/8 bytes of data.
563 * So. The blob contains:
565 * - uint32 0x3f6ff9eb (magic number)
566 * - uint32 size (total blob size)
567 * - string key-type (see below)
568 * - string cipher-type (tells you if key is encrypted)
569 * - string encrypted-blob
571 * (The first size field includes the size field itself and the
572 * magic number before it. All other size fields are ordinary ssh2
573 * strings, so the size field indicates how much data is to
576 * The encrypted blob, once decrypted, contains a single string
577 * which in turn contains the payload. (This allows padding to be
578 * added after that string while still making it clear where the
579 * real payload ends. Also it probably makes for a reasonable
582 * The payload blob, for an RSA key, contains:
585 * - mpint n (yes, the public and private stuff is intermixed)
586 * - mpint u (presumably inverse of p mod q)
587 * - mpint p (p is the smaller prime)
588 * - mpint q (q is the larger)
590 * For a DSA key, the payload blob contains:
598 * Alternatively, if the parameters are `predefined', that
599 * (0,p,g,q) sequence can be replaced by a uint32 1 and a string
600 * containing some predefined parameter specification. *shudder*,
601 * but I doubt we'll encounter this in real life.
603 * The key type strings are ghastly. The RSA key I looked at had a
606 * `if-modn{sign{rsa-pkcs1-sha1},encrypt{rsa-pkcs1v2-oaep}}'
608 * and the DSA key wasn't much better:
610 * `dl-modp{sign{dsa-nist-sha1},dh{plain}}'
612 * It isn't clear that these will always be the same. I think it
613 * might be wise just to look at the `if-modn{sign{rsa' and
614 * `dl-modp{sign{dsa' prefixes.
616 * Finally, the encryption. The cipher-type string appears to be
617 * either `none' or `3des-cbc'. Looks as if this is SSH2-style
618 * 3des-cbc (i.e. outer cbc rather than inner). The key is created
619 * from the passphrase by means of yet another hashing faff:
621 * - first 16 bytes are MD5(passphrase)
622 * - next 16 bytes are MD5(passphrase || first 16 bytes)
623 * - if there were more, they'd be MD5(passphrase || first 32),
628 char comment[256]; /* allowing any length is overkill */
629 unsigned char *keyblob;
630 int keyblob_len, keyblob_size;
633 struct sshcom_key *load_sshcom_key(char *filename)
635 struct sshcom_key *ret;
642 int base64_chars = 0;
644 ret = smalloc(sizeof(*ret));
645 ret->comment[0] = '\0';
647 ret->keyblob_len = ret->keyblob_size = 0;
649 fp = fopen(filename, "r");
651 errmsg = "Unable to open key file";
654 if (!fgets(buffer, sizeof(buffer), fp) ||
655 0 != strcmp(buffer, "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----\n")) {
656 errmsg = "File does not begin with ssh.com key header";
662 if (!fgets(buffer, sizeof(buffer), fp)) {
663 errmsg = "Unexpected end of file";
666 if (!strcmp(buffer, "---- END SSH2 ENCRYPTED PRIVATE KEY ----\n"))
668 if ((p = strchr(buffer, ':')) != NULL) {
670 errmsg = "Header found in body of key data";
674 while (*p && isspace((unsigned char)*p)) p++;
676 * Header lines can end in a trailing backslash for
679 while ((len = strlen(p)) > sizeof(buffer) - (p-buffer) -1 ||
680 p[len-1] != '\n' || p[len-2] == '\\') {
681 if (len > (p-buffer) + sizeof(buffer)-2) {
682 errmsg = "Header line too long to deal with";
685 if (!fgets(p+len-2, sizeof(buffer)-(p-buffer)-(len-2), fp)) {
686 errmsg = "Unexpected end of file";
690 p[strcspn(p, "\n")] = '\0';
691 if (!strcmp(buffer, "Comment")) {
692 /* Strip quotes in comment if present. */
693 if (p[0] == '"' && p[strlen(p)-1] == '"') {
695 p[strlen(p)-1] = '\0';
697 strncpy(ret->comment, p, sizeof(ret->comment));
698 ret->comment[sizeof(ret->comment)-1] = '\0';
704 while (isbase64(*p)) {
705 base64_bit[base64_chars++] = *p;
706 if (base64_chars == 4) {
707 unsigned char out[3];
711 len = base64_decode_atom(base64_bit, out);
714 errmsg = "Invalid base64 encoding";
718 if (ret->keyblob_len + len > ret->keyblob_size) {
719 ret->keyblob_size = ret->keyblob_len + len + 256;
720 ret->keyblob = srealloc(ret->keyblob, ret->keyblob_size);
723 memcpy(ret->keyblob + ret->keyblob_len, out, len);
724 ret->keyblob_len += len;
732 if (ret->keyblob_len == 0 || !ret->keyblob) {
733 errmsg = "Key body not present";
742 memset(ret->keyblob, 0, ret->keyblob_size);
745 memset(&ret, 0, sizeof(ret));
751 int sshcom_encrypted(char *filename, char **comment)
753 struct sshcom_key *key = load_sshcom_key(filename);
754 int pos, len, answer;
761 * Check magic number.
763 if (GET_32BIT(key->keyblob) != 0x3f6ff9eb)
764 return 0; /* key is invalid */
767 * Find the cipher-type string.
771 if (key->keyblob_len < pos+4)
772 goto done; /* key is far too short */
773 pos += 4 + GET_32BIT(key->keyblob + pos); /* skip key type */
774 if (key->keyblob_len < pos+4)
775 goto done; /* key is far too short */
776 len = GET_32BIT(key->keyblob + pos); /* find cipher-type length */
777 if (key->keyblob_len < pos+4+len)
778 goto done; /* cipher type string is incomplete */
779 if (len != 4 || 0 != memcmp(key->keyblob + pos + 4, "none", 4))
783 *comment = dupstr(key->comment);
784 memset(key->keyblob, 0, key->keyblob_size);
786 memset(&key, 0, sizeof(key));
791 struct mpint_pos { void *start; int bytes; };
793 int sshcom_read_mpint(void *data, int len, struct mpint_pos *ret)
797 unsigned char *d = (unsigned char *) data;
803 bytes = (bits + 7) / 8;
814 return len; /* ensure further calls fail as well */
817 struct ssh2_userkey *sshcom_read(char *filename, char *passphrase)
819 struct sshcom_key *key = load_sshcom_key(filename);
822 const char prefix_rsa[] = "if-modn{sign{rsa";
823 const char prefix_dsa[] = "dl-modp{sign{dsa";
824 enum { RSA, DSA } type;
828 struct ssh2_userkey *ret = NULL, *retkey;
829 const struct ssh_signkey *alg;
830 unsigned char *blob = NULL;
831 int blobsize, publen, privlen;
837 * Check magic number.
839 if (GET_32BIT(key->keyblob) != 0x3f6ff9eb) {
840 errmsg = "Key does not begin with magic number";
845 * Determine the key type.
848 if (key->keyblob_len < pos+4 ||
849 (len = GET_32BIT(key->keyblob + pos)) > key->keyblob_len - pos - 4) {
850 errmsg = "Key blob does not contain a key type string";
853 if (len > sizeof(prefix_rsa) - 1 &&
854 !memcmp(key->keyblob+pos+4, prefix_rsa, sizeof(prefix_rsa) - 1)) {
856 } else if (len > sizeof(prefix_dsa) - 1 &&
857 !memcmp(key->keyblob+pos+4, prefix_dsa, sizeof(prefix_dsa) - 1)) {
860 errmsg = "Key is of unknown type";
866 * Determine the cipher type.
868 if (key->keyblob_len < pos+4 ||
869 (len = GET_32BIT(key->keyblob + pos)) > key->keyblob_len - pos - 4) {
870 errmsg = "Key blob does not contain a cipher type string";
873 if (len == 4 && !memcmp(key->keyblob+pos+4, "none", 4))
875 else if (len == 8 && !memcmp(key->keyblob+pos+4, "3des-cbc", 8))
878 errmsg = "Key encryption is of unknown type";
884 * Get hold of the encrypted part of the key.
886 if (key->keyblob_len < pos+4 ||
887 (len = GET_32BIT(key->keyblob + pos)) > key->keyblob_len - pos - 4) {
888 errmsg = "Key blob does not contain actual key data";
891 ciphertext = key->keyblob + pos + 4;
893 if (cipherlen == 0) {
894 errmsg = "Length of key data is zero";
899 * Decrypt it if necessary.
903 * Derive encryption key from passphrase and iv/salt:
905 * - let block A equal MD5(passphrase)
906 * - let block B equal MD5(passphrase || A)
907 * - block C would be MD5(passphrase || A || B) and so on
908 * - encryption key is the first N bytes of A || B
910 struct MD5Context md5c;
911 unsigned char keybuf[32], iv[8];
913 if (cipherlen % 8 != 0) {
914 errmsg = "Encrypted part of key is not a multiple of cipher block"
920 MD5Update(&md5c, passphrase, strlen(passphrase));
921 MD5Final(keybuf, &md5c);
924 MD5Update(&md5c, passphrase, strlen(passphrase));
925 MD5Update(&md5c, keybuf, 16);
926 MD5Final(keybuf+16, &md5c);
929 * Now decrypt the key blob.
931 memset(iv, 0, sizeof(iv));
932 des3_decrypt_pubkey_ossh(keybuf, iv, ciphertext, cipherlen);
934 memset(&md5c, 0, sizeof(md5c));
935 memset(keybuf, 0, sizeof(keybuf));
938 * Hereafter we return WRONG_PASSPHRASE for any parsing
939 * error. (But only if we've just tried to decrypt it!
940 * Returning WRONG_PASSPHRASE for an unencrypted key is
944 ret = SSH2_WRONG_PASSPHRASE;
948 * Strip away the containing string to get to the real meat.
950 len = GET_32BIT(ciphertext);
951 if (len > cipherlen-4) {
952 errmsg = "containing string was ill-formed";
959 * Now we break down into RSA versus DSA. In either case we'll
960 * construct public and private blobs in our own format, and
961 * end up feeding them to alg->createkey().
963 blobsize = cipherlen + 256;
964 blob = smalloc(blobsize);
967 struct mpint_pos n, e, d, u, p, q;
969 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &e);
970 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &d);
971 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &n);
972 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &u);
973 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &p);
974 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &q);
976 errmsg = "key data did not contain six integers";
982 pos += put_string(blob+pos, "ssh-rsa", 7);
983 pos += put_mp(blob+pos, e.start, e.bytes);
984 pos += put_mp(blob+pos, n.start, n.bytes);
986 pos += put_string(blob+pos, d.start, d.bytes);
987 pos += put_mp(blob+pos, q.start, q.bytes);
988 pos += put_mp(blob+pos, p.start, p.bytes);
989 pos += put_mp(blob+pos, u.start, u.bytes);
990 privlen = pos - publen;
991 } else if (type == DSA) {
992 struct mpint_pos p, q, g, x, y;
994 if (GET_32BIT(ciphertext) != 0) {
995 errmsg = "predefined DSA parameters not supported";
998 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &p);
999 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &g);
1000 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &q);
1001 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &y);
1002 pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &x);
1004 errmsg = "key data did not contain five integers";
1010 pos += put_string(blob+pos, "ssh-dss", 7);
1011 pos += put_mp(blob+pos, p.start, p.bytes);
1012 pos += put_mp(blob+pos, q.start, q.bytes);
1013 pos += put_mp(blob+pos, g.start, g.bytes);
1014 pos += put_mp(blob+pos, y.start, y.bytes);
1016 pos += put_mp(blob+pos, x.start, x.bytes);
1017 privlen = pos - publen;
1020 assert(privlen > 0); /* should have bombed by now if not */
1022 retkey = smalloc(sizeof(struct ssh2_userkey));
1024 retkey->data = alg->createkey(blob, publen, blob+publen, privlen);
1025 if (!retkey->data) {
1027 errmsg = "unable to create key data structure";
1030 retkey->comment = dupstr(key->comment);
1032 errmsg = NULL; /* no error */
1037 memset(blob, 0, blobsize);
1040 memset(key->keyblob, 0, key->keyblob_size);
1041 sfree(key->keyblob);
1042 memset(&key, 0, sizeof(key));