if (len < 4)
goto error;
- bytes = GET_32BIT(d);
- if (len < 4+bytes)
+ bytes = toint(GET_32BIT(d));
+ if (bytes < 0 || len-4 < bytes)
goto error;
ret->start = d + 4;
* Code to read and write OpenSSH private keys.
*/
-enum { OSSH_DSA, OSSH_RSA };
-enum { OSSH_ENC_3DES, OSSH_ENC_AES };
+typedef enum {
+ OSSH_DSA, OSSH_RSA, OSSH_ECDSA, OSSH_DUNNO_YET
+} openssh_keytype;
+typedef enum {
+ OSSH_FMT_OLD, OSSH_FMT_NEW
+} openssh_keyfmt;
+typedef enum {
+ OSSH_ENC_3DES, OSSH_ENC_AES
+} openssh_old_enc;
+typedef enum {
+ OSSH_E_NONE, OSSH_E_AES256CBC
+} openssh_new_cipher;
+typedef enum {
+ OSSH_K_NONE, OSSH_K_BCRYPT
+} openssh_new_kdf;
+
struct openssh_key {
- int type;
- int encrypted, encryption;
- char iv[32];
+ openssh_keytype keytype;
+ openssh_keyfmt keyfmt;
+ int encrypted;
+ union {
+ struct {
+ openssh_old_enc encryption;
+ char iv[32];
+ } old;
+ struct {
+ openssh_new_cipher cipher;
+ openssh_new_kdf kdf;
+ union {
+ struct {
+ int rounds;
+ /* This points to a position within keyblob, not a
+ * separately allocated thing */
+ const unsigned char *salt;
+ int saltlen;
+ } bcrypt;
+ } kdfopts;
+ int nkeys, key_wanted;
+ /* This too points to a position within keyblob */
+ unsigned char *privatestr;
+ int privatelen;
+ } new;
+ } u;
unsigned char *keyblob;
int keyblob_len, keyblob_size;
};
+static int decrypt_openssh_key(struct openssh_key *key,
+ const char *passphrase,
+ char **errmsg)
+{
+ assert(key->encrypted);
+ if (key->keyfmt == OSSH_FMT_OLD) {
+ /*
+ * Derive encryption key from passphrase and iv/salt:
+ *
+ * - let block A equal MD5(passphrase || iv)
+ * - let block B equal MD5(A || passphrase || iv)
+ * - block C would be MD5(B || passphrase || iv) and so on
+ * - encryption key is the first N bytes of A || B
+ *
+ * (Note that only 8 bytes of the iv are used for key
+ * derivation, even when the key is encrypted with AES and
+ * hence there are 16 bytes available.)
+ */
+ struct MD5Context md5c;
+ unsigned char keybuf[32];
+
+ MD5Init(&md5c);
+ MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
+ MD5Update(&md5c, (unsigned char *)key->u.old.iv, 8);
+ MD5Final(keybuf, &md5c);
+
+ MD5Init(&md5c);
+ MD5Update(&md5c, keybuf, 16);
+ MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
+ MD5Update(&md5c, (unsigned char *)key->u.old.iv, 8);
+ MD5Final(keybuf+16, &md5c);
+
+ /*
+ * Now decrypt the key blob.
+ */
+ if (key->u.old.encryption == OSSH_ENC_3DES)
+ des3_decrypt_pubkey_ossh(keybuf, (unsigned char *)key->u.old.iv,
+ key->keyblob, key->keyblob_len);
+ else {
+ void *ctx;
+ assert(key->u.old.encryption == OSSH_ENC_AES);
+ ctx = aes_make_context();
+ aes128_key(ctx, keybuf);
+ aes_iv(ctx, (unsigned char *)key->u.old.iv);
+ aes_ssh2_decrypt_blk(ctx, key->keyblob, key->keyblob_len);
+ aes_free_context(ctx);
+ }
+
+ smemclr(&md5c, sizeof(md5c));
+ smemclr(keybuf, sizeof(keybuf));
+
+ return TRUE;
+ }
+
+ if (key->keyfmt == OSSH_FMT_NEW) {
+ unsigned char keybuf[48];
+ int keysize;
+
+ /*
+ * Construct the decryption key, and decrypt the string.
+ */
+ switch (key->u.new.cipher) {
+ case OSSH_E_NONE:
+ keysize = 0;
+ break;
+ case OSSH_E_AES256CBC:
+ keysize = 48; /* 32 byte key + 16 byte IV */
+ break;
+ default:
+ assert(0 && "Bad cipher enumeration value");
+ }
+ assert(keysize <= sizeof(keybuf));
+ switch (key->u.new.kdf) {
+ case OSSH_K_NONE:
+ memset(keybuf, 0, keysize);
+ break;
+ case OSSH_K_BCRYPT:
+ openssh_bcrypt(passphrase,
+ key->u.new.kdfopts.bcrypt.salt,
+ key->u.new.kdfopts.bcrypt.saltlen,
+ key->u.new.kdfopts.bcrypt.rounds,
+ keybuf, keysize);
+ break;
+ default:
+ assert(0 && "Bad kdf enumeration value");
+ }
+ switch (key->u.new.cipher) {
+ case OSSH_E_NONE:
+ break;
+ case OSSH_E_AES256CBC:
+ if (key->u.new.privatelen % 16 != 0) {
+ *errmsg = "private key container length is not a"
+ " multiple of AES block size\n";
+ return FALSE;
+ }
+ {
+ void *ctx = aes_make_context();
+ aes256_key(ctx, keybuf);
+ aes_iv(ctx, keybuf + 32);
+ aes_ssh2_decrypt_blk(ctx, key->u.new.privatestr,
+ key->u.new.privatelen);
+ aes_free_context(ctx);
+ }
+ break;
+ default:
+ assert(0 && "Bad cipher enumeration value");
+ }
+ return TRUE;
+ }
+
+ assert(0 && "Bad key format in decrypt_openssh_key");
+}
+
static struct openssh_key *load_openssh_key(const Filename *filename,
const char **errmsg_p)
{
struct openssh_key *ret;
- FILE *fp;
+ FILE *fp = NULL;
char *line = NULL;
char *errmsg, *p;
int headers_done;
ret = snew(struct openssh_key);
ret->keyblob = NULL;
ret->keyblob_len = ret->keyblob_size = 0;
- ret->encrypted = 0;
- memset(ret->iv, 0, sizeof(ret->iv));
- fp = f_open(*filename, "r", FALSE);
+ fp = f_open(filename, "r", FALSE);
if (!fp) {
errmsg = "unable to open key file";
goto error;
errmsg = "file does not begin with OpenSSH key header";
goto error;
}
- if (!strcmp(line, "-----BEGIN RSA PRIVATE KEY-----"))
- ret->type = OSSH_RSA;
- else if (!strcmp(line, "-----BEGIN DSA PRIVATE KEY-----"))
- ret->type = OSSH_DSA;
- else {
+ /*
+ * Parse the BEGIN line. For old-format keys, this tells us the
+ * type of the key; for new-format keys, all it tells us is the
+ * format, and we'll find out the key type once we parse the
+ * base64.
+ */
+ if (!strcmp(line, "-----BEGIN RSA PRIVATE KEY-----")) {
+ ret->keyfmt = OSSH_FMT_OLD;
+ ret->keytype = OSSH_RSA;
+ } else if (!strcmp(line, "-----BEGIN DSA PRIVATE KEY-----")) {
+ ret->keyfmt = OSSH_FMT_OLD;
+ ret->keytype = OSSH_DSA;
+ } else if (!strcmp(line, "-----BEGIN EC PRIVATE KEY-----")) {
+ ret->keyfmt = OSSH_FMT_OLD;
+ ret->keytype = OSSH_ECDSA;
+ } else if (!strcmp(line, "-----BEGIN OPENSSH PRIVATE KEY-----")) {
+ ret->keyfmt = OSSH_FMT_NEW;
+ ret->keytype = OSSH_DUNNO_YET;
+ } else {
errmsg = "unrecognised key type";
goto error;
}
- memset(line, 0, strlen(line));
+ smemclr(line, strlen(line));
sfree(line);
line = NULL;
+ if (ret->keyfmt == OSSH_FMT_OLD) {
+ ret->encrypted = FALSE;
+ memset(ret->u.old.iv, 0, sizeof(ret->u.old.iv));
+ }
+
headers_done = 0;
while (1) {
if (!(line = fgetline(fp))) {
}
strip_crlf(line);
if (0 == strncmp(line, "-----END ", 9) &&
- 0 == strcmp(line+strlen(line)-16, "PRIVATE KEY-----"))
+ 0 == strcmp(line+strlen(line)-16, "PRIVATE KEY-----")) {
+ sfree(line);
+ line = NULL;
break; /* done */
+ }
if ((p = strchr(line, ':')) != NULL) {
+ if (ret->keyfmt != OSSH_FMT_OLD) {
+ errmsg = "expected no headers in new-style OpenSSH key format";
+ goto error;
+ }
if (headers_done) {
errmsg = "header found in body of key data";
goto error;
}
p += 2;
if (!strcmp(p, "ENCRYPTED"))
- ret->encrypted = 1;
+ ret->encrypted = TRUE;
} else if (!strcmp(line, "DEK-Info")) {
int i, j, ivlen;
if (!strncmp(p, "DES-EDE3-CBC,", 13)) {
- ret->encryption = OSSH_ENC_3DES;
+ ret->u.old.encryption = OSSH_ENC_3DES;
ivlen = 8;
} else if (!strncmp(p, "AES-128-CBC,", 12)) {
- ret->encryption = OSSH_ENC_AES;
+ ret->u.old.encryption = OSSH_ENC_AES;
ivlen = 16;
} else {
errmsg = "unsupported cipher";
errmsg = "expected more iv data in DEK-Info";
goto error;
}
- ret->iv[i] = j;
+ ret->u.old.iv[i] = j;
p += 2;
}
if (*p) {
memcpy(ret->keyblob + ret->keyblob_len, out, len);
ret->keyblob_len += len;
- memset(out, 0, sizeof(out));
+ smemclr(out, sizeof(out));
}
p++;
}
}
- memset(line, 0, strlen(line));
+ smemclr(line, strlen(line));
sfree(line);
line = NULL;
}
+ fclose(fp);
+ fp = NULL;
+
if (ret->keyblob_len == 0 || !ret->keyblob) {
errmsg = "key body not present";
goto error;
}
- if (ret->encrypted && ret->keyblob_len % 8 != 0) {
- errmsg = "encrypted key blob is not a multiple of cipher block size";
- goto error;
+ if (ret->keyfmt == OSSH_FMT_NEW) {
+ /*
+ * If we get here, then we haven't boiled down to a private
+ * key blob after all; we've merely stripped the base64
+ * wrapping from a new-style OpenSSH private key file. Now we
+ * have to parse that in turn, or at least get as far as the
+ * encrypted section.
+ */
+ const void *filedata = ret->keyblob;
+ int filelen = ret->keyblob_len;
+ const void *string, *kdfopts, *bcryptsalt, *pubkey;
+ int stringlen, kdfoptlen, bcryptsaltlen, pubkeylen;
+ unsigned bcryptrounds, nkeys, key_index;
+
+ if (filelen < 15 || 0 != memcmp(filedata, "openssh-key-v1\0", 15)) {
+ errmsg = "new-style OpenSSH magic number missing\n";
+ goto error;
+ }
+ filedata = (const char *)filedata + 15;
+ filelen -= 15;
+
+ if (!(string = get_ssh_string(&filelen, &filedata, &stringlen))) {
+ errmsg = "encountered EOF before cipher name\n";
+ goto error;
+ }
+ if (match_ssh_id(stringlen, string, "none")) {
+ ret->u.new.cipher = OSSH_E_NONE;
+ } else if (match_ssh_id(stringlen, string, "aes256-cbc")) {
+ ret->u.new.cipher = OSSH_E_AES256CBC;
+ } else {
+ errmsg = "unrecognised cipher name\n";
+ goto error;
+ }
+
+ if (!(string = get_ssh_string(&filelen, &filedata, &stringlen))) {
+ errmsg = "encountered EOF before kdf name\n";
+ goto error;
+ }
+ if (match_ssh_id(stringlen, string, "none")) {
+ ret->u.new.kdf = OSSH_K_NONE;
+ } else if (match_ssh_id(stringlen, string, "bcrypt")) {
+ ret->u.new.kdf = OSSH_K_BCRYPT;
+ } else {
+ errmsg = "unrecognised kdf name\n";
+ goto error;
+ }
+
+ if (!(kdfopts = get_ssh_string(&filelen, &filedata, &kdfoptlen))) {
+ errmsg = "encountered EOF before kdf options\n";
+ goto error;
+ }
+ switch (ret->u.new.kdf) {
+ case OSSH_K_NONE:
+ if (kdfoptlen != 0) {
+ errmsg = "expected empty options string for 'none' kdf";
+ goto error;
+ }
+ break;
+ case OSSH_K_BCRYPT:
+ if (!(bcryptsalt = get_ssh_string(&kdfoptlen, &kdfopts,
+ &bcryptsaltlen))) {
+ errmsg = "bcrypt options string did not contain salt\n";
+ goto error;
+ }
+ if (!get_ssh_uint32(&kdfoptlen, &kdfopts, &bcryptrounds)) {
+ errmsg = "bcrypt options string did not contain round count\n";
+ goto error;
+ }
+ ret->u.new.kdfopts.bcrypt.salt = bcryptsalt;
+ ret->u.new.kdfopts.bcrypt.saltlen = bcryptsaltlen;
+ ret->u.new.kdfopts.bcrypt.rounds = bcryptrounds;
+ break;
+ }
+
+ ret->encrypted = (ret->u.new.cipher != OSSH_E_NONE);
+
+ /*
+ * At this point we expect a uint32 saying how many keys are
+ * stored in this file. OpenSSH new-style key files can
+ * contain more than one. Currently we don't have any user
+ * interface to specify which one we're trying to extract, so
+ * we just bomb out with an error if more than one is found in
+ * the file. However, I've put in all the mechanism here to
+ * extract the nth one for a given n, in case we later connect
+ * up some UI to that mechanism. Just arrange that the
+ * 'key_wanted' field is set to a value in the range [0,
+ * nkeys) by some mechanism.
+ */
+ if (!get_ssh_uint32(&filelen, &filedata, &nkeys)) {
+ errmsg = "encountered EOF before key count\n";
+ goto error;
+ }
+ if (nkeys != 1) {
+ errmsg = "multiple keys in new-style OpenSSH key file "
+ "not supported\n";
+ goto error;
+ }
+ ret->u.new.nkeys = nkeys;
+ ret->u.new.key_wanted = 0;
+
+ for (key_index = 0; key_index < nkeys; key_index++) {
+ int this_keytype;
+ if (!(pubkey = get_ssh_string(&filelen, &filedata, &pubkeylen))) {
+ errmsg = "encountered EOF before kdf options\n";
+ goto error;
+ }
+ /*
+ * Check the key type, and make sure it's something we
+ * understand.
+ */
+ if (!(string = get_ssh_string(&pubkeylen, &pubkey,
+ &stringlen))) {
+ errmsg = "public key did not start with type string\n";
+ goto error;
+ }
+ if (match_ssh_id(stringlen, string, "ssh-rsa")) {
+ this_keytype = OSSH_RSA;
+ } else if (match_ssh_id(stringlen, string, "ssh-dss")) {
+ this_keytype = OSSH_DSA;
+ } else if (match_ssh_id(stringlen, string,
+ "ecdsa-sha2-nistp256") ||
+ match_ssh_id(stringlen, string,
+ "ecdsa-sha2-nistp384") ||
+ match_ssh_id(stringlen, string,
+ "ecdsa-sha2-nistp521")) {
+ this_keytype = OSSH_ECDSA;
+ } else {
+ errmsg = "public key did not start with type string\n";
+ goto error;
+ }
+ if (key_index == ret->u.new.key_wanted)
+ ret->keytype = this_keytype;
+ }
+
+ /*
+ * Now we expect a string containing the encrypted part of the
+ * key file.
+ */
+ if (!(string = get_ssh_string(&filelen, &filedata, &stringlen))) {
+ errmsg = "encountered EOF before private key container\n";
+ goto error;
+ }
+ ret->u.new.privatestr = (unsigned char *)string;
+ ret->u.new.privatelen = stringlen;
+
+ /*
+ * And now we're done, until asked to actually decrypt.
+ */
}
- memset(base64_bit, 0, sizeof(base64_bit));
+ if (ret->keyfmt == OSSH_FMT_OLD) {
+ if (ret->encrypted && ret->keyblob_len % 8 != 0) {
+ errmsg = "encrypted key blob is not a multiple of "
+ "cipher block size";
+ goto error;
+ }
+ }
+
+ smemclr(base64_bit, sizeof(base64_bit));
if (errmsg_p) *errmsg_p = NULL;
return ret;
error:
if (line) {
- memset(line, 0, strlen(line));
+ smemclr(line, strlen(line));
sfree(line);
line = NULL;
}
- memset(base64_bit, 0, sizeof(base64_bit));
+ smemclr(base64_bit, sizeof(base64_bit));
if (ret) {
if (ret->keyblob) {
- memset(ret->keyblob, 0, ret->keyblob_size);
+ smemclr(ret->keyblob, ret->keyblob_size);
sfree(ret->keyblob);
}
- memset(ret, 0, sizeof(*ret));
+ smemclr(ret, sizeof(*ret));
sfree(ret);
}
if (errmsg_p) *errmsg_p = errmsg;
+ if (fp) fclose(fp);
return NULL;
}
if (!key)
return 0;
ret = key->encrypted;
- memset(key->keyblob, 0, key->keyblob_size);
+ smemclr(key->keyblob, key->keyblob_size);
sfree(key->keyblob);
- memset(key, 0, sizeof(*key));
+ smemclr(key, sizeof(*key));
sfree(key);
return ret;
}
return NULL;
if (key->encrypted) {
- /*
- * Derive encryption key from passphrase and iv/salt:
- *
- * - let block A equal MD5(passphrase || iv)
- * - let block B equal MD5(A || passphrase || iv)
- * - block C would be MD5(B || passphrase || iv) and so on
- * - encryption key is the first N bytes of A || B
- *
- * (Note that only 8 bytes of the iv are used for key
- * derivation, even when the key is encrypted with AES and
- * hence there are 16 bytes available.)
- */
- struct MD5Context md5c;
- unsigned char keybuf[32];
+ if (!decrypt_openssh_key(key, passphrase, &errmsg))
+ goto error;
+ }
- MD5Init(&md5c);
- MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
- MD5Update(&md5c, (unsigned char *)key->iv, 8);
- MD5Final(keybuf, &md5c);
+ if (key->keyfmt == OSSH_FMT_OLD) {
+ /*
+ * Now we have a decrypted key blob, which contains an ASN.1
+ * encoded private key. We must now untangle the ASN.1.
+ *
+ * We expect the whole key blob to be formatted as a SEQUENCE
+ * (0x30 followed by a length code indicating that the rest of
+ * the blob is part of the sequence). Within that SEQUENCE we
+ * expect to see a bunch of INTEGERs. What those integers mean
+ * depends on the key type:
+ *
+ * - For RSA, we expect the integers to be 0, n, e, d, p, q,
+ * dmp1, dmq1, iqmp in that order. (The last three are d mod
+ * (p-1), d mod (q-1), inverse of q mod p respectively.)
+ *
+ * - For DSA, we expect them to be 0, p, q, g, y, x in that
+ * order.
+ *
+ * - In ECDSA the format is totally different: we see the
+ * SEQUENCE, but beneath is an INTEGER 1, OCTET STRING priv
+ * EXPLICIT [0] OID curve, EXPLICIT [1] BIT STRING pubPoint
+ */
+
+ p = key->keyblob;
+
+ /* Expect the SEQUENCE header. Take its absence as a failure to
+ * decrypt, if the key was encrypted. */
+ ret = ber_read_id_len(p, key->keyblob_len, &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 16) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
- MD5Init(&md5c);
- MD5Update(&md5c, keybuf, 16);
- MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
- MD5Update(&md5c, (unsigned char *)key->iv, 8);
- MD5Final(keybuf+16, &md5c);
+ /* Expect a load of INTEGERs. */
+ if (key->keytype == OSSH_RSA)
+ num_integers = 9;
+ else if (key->keytype == OSSH_DSA)
+ num_integers = 6;
+ else
+ num_integers = 0; /* placate compiler warnings */
+
+
+ if (key->keytype == OSSH_ECDSA) {
+ /* And now for something completely different */
+ unsigned char *priv;
+ int privlen;
+ struct ec_curve *curve;
+ /* Read INTEGER 1 */
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 2 || key->keyblob+key->keyblob_len-p < len ||
+ len != 1 || p[0] != 1) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
+ p += 1;
+ /* Read private key OCTET STRING */
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 4 || key->keyblob+key->keyblob_len-p < len) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
+ priv = p;
+ privlen = len;
+ p += len;
+ /* Read curve OID */
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 0 || key->keyblob+key->keyblob_len-p < len) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 6 || key->keyblob+key->keyblob_len-p < len) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
+ if (len == 8 && !memcmp(p, nistp256_oid, nistp256_oid_len)) {
+ curve = ec_p256();
+ } else if (len == 5 && !memcmp(p, nistp384_oid,
+ nistp384_oid_len)) {
+ curve = ec_p384();
+ } else if (len == 5 && !memcmp(p, nistp521_oid,
+ nistp521_oid_len)) {
+ curve = ec_p521();
+ } else {
+ errmsg = "Unsupported ECDSA curve.";
+ retval = NULL;
+ goto error;
+ }
+ p += len;
+ /* Read BIT STRING point */
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 1 || key->keyblob+key->keyblob_len-p < len) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 3 || key->keyblob+key->keyblob_len-p < len ||
+ len != ((((curve->fieldBits + 7) / 8) * 2) + 2)) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
+ p += 1; len -= 1; /* Skip 0x00 before point */
- /*
- * Now decrypt the key blob.
- */
- if (key->encryption == OSSH_ENC_3DES)
- des3_decrypt_pubkey_ossh(keybuf, (unsigned char *)key->iv,
- key->keyblob, key->keyblob_len);
- else {
- void *ctx;
- assert(key->encryption == OSSH_ENC_AES);
- ctx = aes_make_context();
- aes128_key(ctx, keybuf);
- aes_iv(ctx, (unsigned char *)key->iv);
- aes_ssh2_decrypt_blk(ctx, key->keyblob, key->keyblob_len);
- aes_free_context(ctx);
- }
+ /* Construct the key */
+ retkey = snew(struct ssh2_userkey);
+ if (!retkey) {
+ errmsg = "out of memory";
+ goto error;
+ }
+ if (curve->fieldBits == 256) {
+ retkey->alg = &ssh_ecdsa_nistp256;
+ } else if (curve->fieldBits == 384) {
+ retkey->alg = &ssh_ecdsa_nistp384;
+ } else {
+ retkey->alg = &ssh_ecdsa_nistp521;
+ }
+ blob = snewn((4+19 + 4+8 + 4+len) + (4+privlen), unsigned char);
+ if (!blob) {
+ sfree(retkey);
+ errmsg = "out of memory";
+ goto error;
+ }
+ PUT_32BIT(blob, 19);
+ sprintf((char*)blob+4, "ecdsa-sha2-nistp%d", curve->fieldBits);
+ PUT_32BIT(blob+4+19, 8);
+ sprintf((char*)blob+4+19+4, "nistp%d", curve->fieldBits);
+ PUT_32BIT(blob+4+19+4+8, len);
+ memcpy(blob+4+19+4+8+4, p, len);
+ PUT_32BIT(blob+4+19+4+8+4+len, privlen);
+ memcpy(blob+4+19+4+8+4+len+4, priv, privlen);
+ retkey->data = retkey->alg->createkey(blob, 4+19+4+8+4+len,
+ blob+4+19+4+8+4+len,
+ 4+privlen);
+ if (!retkey->data) {
+ sfree(retkey);
+ errmsg = "unable to create key data structure";
+ goto error;
+ }
- memset(&md5c, 0, sizeof(md5c));
- memset(keybuf, 0, sizeof(keybuf));
- }
+ } else if (key->keytype == OSSH_RSA || key->keytype == OSSH_DSA) {
- /*
- * Now we have a decrypted key blob, which contains an ASN.1
- * encoded private key. We must now untangle the ASN.1.
- *
- * We expect the whole key blob to be formatted as a SEQUENCE
- * (0x30 followed by a length code indicating that the rest of
- * the blob is part of the sequence). Within that SEQUENCE we
- * expect to see a bunch of INTEGERs. What those integers mean
- * depends on the key type:
- *
- * - For RSA, we expect the integers to be 0, n, e, d, p, q,
- * dmp1, dmq1, iqmp in that order. (The last three are d mod
- * (p-1), d mod (q-1), inverse of q mod p respectively.)
- *
- * - For DSA, we expect them to be 0, p, q, g, y, x in that
- * order.
- */
-
- p = key->keyblob;
-
- /* Expect the SEQUENCE header. Take its absence as a failure to decrypt. */
- ret = ber_read_id_len(p, key->keyblob_len, &id, &len, &flags);
- p += ret;
- if (ret < 0 || id != 16) {
- errmsg = "ASN.1 decoding failure";
- retval = SSH2_WRONG_PASSPHRASE;
- goto error;
- }
+ /*
+ * Space to create key blob in.
+ */
+ blobsize = 256+key->keyblob_len;
+ blob = snewn(blobsize, unsigned char);
+ PUT_32BIT(blob, 7);
+ if (key->keytype == OSSH_DSA)
+ memcpy(blob+4, "ssh-dss", 7);
+ else if (key->keytype == OSSH_RSA)
+ memcpy(blob+4, "ssh-rsa", 7);
+ blobptr = 4+7;
+ privptr = -1;
+
+ for (i = 0; i < num_integers; i++) {
+ ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+ &id, &len, &flags);
+ p += ret;
+ if (ret < 0 || id != 2 ||
+ key->keyblob+key->keyblob_len-p < len) {
+ errmsg = "ASN.1 decoding failure";
+ retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
+ goto error;
+ }
- /* Expect a load of INTEGERs. */
- if (key->type == OSSH_RSA)
- num_integers = 9;
- else if (key->type == OSSH_DSA)
- num_integers = 6;
- else
- num_integers = 0; /* placate compiler warnings */
+ if (i == 0) {
+ /*
+ * The first integer should be zero always (I think
+ * this is some sort of version indication).
+ */
+ if (len != 1 || p[0] != 0) {
+ errmsg = "version number mismatch";
+ goto error;
+ }
+ } else if (key->keytype == OSSH_RSA) {
+ /*
+ * Integers 1 and 2 go into the public blob but in the
+ * opposite order; integers 3, 4, 5 and 8 go into the
+ * private blob. The other two (6 and 7) are ignored.
+ */
+ if (i == 1) {
+ /* Save the details for after we deal with number 2. */
+ modptr = (char *)p;
+ modlen = len;
+ } else if (i != 6 && i != 7) {
+ PUT_32BIT(blob+blobptr, len);
+ memcpy(blob+blobptr+4, p, len);
+ blobptr += 4+len;
+ if (i == 2) {
+ PUT_32BIT(blob+blobptr, modlen);
+ memcpy(blob+blobptr+4, modptr, modlen);
+ blobptr += 4+modlen;
+ privptr = blobptr;
+ }
+ }
+ } else if (key->keytype == OSSH_DSA) {
+ /*
+ * Integers 1-4 go into the public blob; integer 5 goes
+ * into the private blob.
+ */
+ PUT_32BIT(blob+blobptr, len);
+ memcpy(blob+blobptr+4, p, len);
+ blobptr += 4+len;
+ if (i == 4)
+ privptr = blobptr;
+ }
- /*
- * Space to create key blob in.
- */
- blobsize = 256+key->keyblob_len;
- blob = snewn(blobsize, unsigned char);
- PUT_32BIT(blob, 7);
- if (key->type == OSSH_DSA)
- memcpy(blob+4, "ssh-dss", 7);
- else if (key->type == OSSH_RSA)
- memcpy(blob+4, "ssh-rsa", 7);
- blobptr = 4+7;
- privptr = -1;
-
- for (i = 0; i < num_integers; i++) {
- ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
- &id, &len, &flags);
- p += ret;
- if (ret < 0 || id != 2 ||
- key->keyblob+key->keyblob_len-p < len) {
- errmsg = "ASN.1 decoding failure";
- retval = SSH2_WRONG_PASSPHRASE;
- goto error;
- }
+ /* Skip past the number. */
+ p += len;
+ }
- if (i == 0) {
- /*
- * The first integer should be zero always (I think
- * this is some sort of version indication).
- */
- if (len != 1 || p[0] != 0) {
- errmsg = "version number mismatch";
- goto error;
- }
- } else if (key->type == OSSH_RSA) {
- /*
- * Integers 1 and 2 go into the public blob but in the
- * opposite order; integers 3, 4, 5 and 8 go into the
- * private blob. The other two (6 and 7) are ignored.
- */
- if (i == 1) {
- /* Save the details for after we deal with number 2. */
- modptr = (char *)p;
- modlen = len;
- } else if (i != 6 && i != 7) {
- PUT_32BIT(blob+blobptr, len);
- memcpy(blob+blobptr+4, p, len);
- blobptr += 4+len;
- if (i == 2) {
- PUT_32BIT(blob+blobptr, modlen);
- memcpy(blob+blobptr+4, modptr, modlen);
- blobptr += 4+modlen;
- privptr = blobptr;
- }
- }
- } else if (key->type == OSSH_DSA) {
- /*
- * Integers 1-4 go into the public blob; integer 5 goes
- * into the private blob.
- */
- PUT_32BIT(blob+blobptr, len);
- memcpy(blob+blobptr+4, p, len);
- blobptr += 4+len;
- if (i == 4)
- privptr = blobptr;
- }
+ /*
+ * Now put together the actual key. Simplest way to do this is
+ * to assemble our own key blobs and feed them to the createkey
+ * functions; this is a bit faffy but it does mean we get all
+ * the sanity checks for free.
+ */
+ assert(privptr > 0); /* should have bombed by now if not */
+ retkey = snew(struct ssh2_userkey);
+ retkey->alg = (key->keytype == OSSH_RSA ? &ssh_rsa : &ssh_dss);
+ retkey->data = retkey->alg->createkey(blob, privptr,
+ blob+privptr,
+ blobptr-privptr);
+ if (!retkey->data) {
+ sfree(retkey);
+ errmsg = "unable to create key data structure";
+ goto error;
+ }
- /* Skip past the number. */
- p += len;
- }
+ } else {
+ assert(0 && "Bad key type from load_openssh_key");
+ }
- /*
- * Now put together the actual key. Simplest way to do this is
- * to assemble our own key blobs and feed them to the createkey
- * functions; this is a bit faffy but it does mean we get all
- * the sanity checks for free.
- */
- assert(privptr > 0); /* should have bombed by now if not */
- retkey = snew(struct ssh2_userkey);
- retkey->alg = (key->type == OSSH_RSA ? &ssh_rsa : &ssh_dss);
- retkey->data = retkey->alg->createkey(blob, privptr,
- blob+privptr, blobptr-privptr);
- if (!retkey->data) {
- sfree(retkey);
- errmsg = "unable to create key data structure";
- goto error;
+ /*
+ * The old key format doesn't include a comment in the private
+ * key file.
+ */
+ retkey->comment = dupstr("imported-openssh-key");
+ } else if (key->keyfmt == OSSH_FMT_NEW) {
+ unsigned checkint0, checkint1;
+ const void *priv, *string;
+ int privlen, stringlen, key_index;
+ const struct ssh_signkey *alg;
+
+ /*
+ * OpenSSH's new key format. Here we must parse the entire
+ * encrypted section, and extract the key identified by
+ * key_wanted.
+ */
+ priv = key->u.new.privatestr;
+ privlen = key->u.new.privatelen;
+
+ if (!get_ssh_uint32(&privlen, &priv, &checkint0) ||
+ !get_ssh_uint32(&privlen, &priv, &checkint1) ||
+ checkint0 != checkint1) {
+ errmsg = "decryption check failed";
+ goto error;
+ }
+
+ retkey = NULL;
+ for (key_index = 0; key_index < key->u.new.nkeys; key_index++) {
+ unsigned char *thiskey;
+ openssh_keytype this_keytype;
+ int thiskeylen, npieces;
+
+ /*
+ * Read the key type, which will tell us how to scan over
+ * the key to get to the next one.
+ */
+ if (!(string = get_ssh_string(&privlen, &priv, &stringlen))) {
+ errmsg = "expected key type in private string";
+ goto error;
+ }
+
+ /*
+ * Preliminary key type identification, and decide how
+ * many pieces of key we expect to see. Currently
+ * (conveniently) all key types can be seen as some number
+ * of strings, so we just need to know how many of them to
+ * skip over. (The numbers below exclude the key comment.)
+ */
+ if (match_ssh_id(stringlen, string, "ssh-rsa")) {
+ this_keytype = OSSH_RSA;
+ alg = &ssh_rsa;
+ npieces = 6; /* n,e,d,iqmp,q,p */
+ } else if (match_ssh_id(stringlen, string, "ssh-dss")) {
+ this_keytype = OSSH_DSA;
+ alg = &ssh_dss;
+ npieces = 5; /* p,q,g,y,x */
+ } else if (match_ssh_id(stringlen, string,
+ "ecdsa-sha2-nistp256")) {
+ this_keytype = OSSH_ECDSA;
+ alg = &ssh_ecdsa_nistp256;
+ npieces = 3; /* curve name, point, private exponent */
+ } else if (match_ssh_id(stringlen, string,
+ "ecdsa-sha2-nistp384")) {
+ this_keytype = OSSH_ECDSA;
+ alg = &ssh_ecdsa_nistp384;
+ npieces = 3; /* curve name, point, private exponent */
+ } else if (match_ssh_id(stringlen, string,
+ "ecdsa-sha2-nistp521")) {
+ this_keytype = OSSH_ECDSA;
+ alg = &ssh_ecdsa_nistp521;
+ npieces = 3; /* curve name, point, private exponent */
+ } else {
+ errmsg = "private key did not start with type string\n";
+ goto error;
+ }
+
+ thiskey = (unsigned char *)priv;
+
+ /*
+ * Skip over the pieces of key.
+ */
+ for (i = 0; i < npieces; i++) {
+ if (!(string = get_ssh_string(&privlen, &priv, &stringlen))) {
+ errmsg = "ran out of data in mid-private-key";
+ goto error;
+ }
+ }
+
+ thiskeylen = (int)((const unsigned char *)priv -
+ (const unsigned char *)thiskey);
+ if (key_index == key->u.new.key_wanted) {
+ if (this_keytype != key->keytype) {
+ errmsg = "public and private key types did not match";
+ goto error;
+ }
+ retkey = snew(struct ssh2_userkey);
+ retkey->alg = alg;
+ retkey->data = alg->openssh_createkey(&thiskey, &thiskeylen);
+ if (!retkey->data) {
+ sfree(retkey);
+ errmsg = "unable to create key data structure";
+ goto error;
+ }
+ }
+
+ /*
+ * Read the key comment.
+ */
+ if (!(string = get_ssh_string(&privlen, &priv, &stringlen))) {
+ errmsg = "ran out of data at key comment";
+ goto error;
+ }
+ if (key_index == key->u.new.key_wanted) {
+ assert(retkey);
+ retkey->comment = dupprintf("%.*s", stringlen,
+ (const char *)string);
+ }
+ }
+
+ if (!retkey) {
+ errmsg = "key index out of range";
+ goto error;
+ }
+
+ /*
+ * Now we expect nothing left but padding.
+ */
+ for (i = 0; i < privlen; i++) {
+ if (((const unsigned char *)priv)[i] != (unsigned char)(i+1)) {
+ errmsg = "padding at end of private string did not match";
+ goto error;
+ }
+ }
+ } else {
+ assert(0 && "Bad key format from load_openssh_key");
}
- retkey->comment = dupstr("imported-openssh-key");
errmsg = NULL; /* no error */
retval = retkey;
error:
if (blob) {
- memset(blob, 0, blobsize);
+ smemclr(blob, blobsize);
sfree(blob);
}
- memset(key->keyblob, 0, key->keyblob_size);
+ smemclr(key->keyblob, key->keyblob_size);
sfree(key->keyblob);
- memset(key, 0, sizeof(*key));
+ smemclr(key, sizeof(*key));
sfree(key);
if (errmsg_p) *errmsg_p = errmsg;
return retval;
privblob = key->alg->private_blob(key->data, &privlen);
spareblob = outblob = NULL;
+ outblob = NULL;
+ len = 0;
+
/*
- * Find the sequence of integers to be encoded into the OpenSSH
- * key blob, and also decide on the header line.
+ * Encode the OpenSSH key blob, and also decide on the header
+ * line.
*/
- if (key->alg == &ssh_rsa) {
- int pos;
- struct mpint_pos n, e, d, p, q, iqmp, dmp1, dmq1;
- Bignum bd, bp, bq, bdmp1, bdmq1;
+ if (key->alg == &ssh_rsa || key->alg == &ssh_dss) {
+ /*
+ * The RSA and DSS handlers share some code because the two
+ * key types have very similar ASN.1 representations, as a
+ * plain SEQUENCE of big integers. So we set up a list of
+ * bignums per key type and then construct the actual blob in
+ * common code after that.
+ */
+ if (key->alg == &ssh_rsa) {
+ int pos;
+ struct mpint_pos n, e, d, p, q, iqmp, dmp1, dmq1;
+ Bignum bd, bp, bq, bdmp1, bdmq1;
- pos = 4 + GET_32BIT(pubblob);
- pos += ssh2_read_mpint(pubblob+pos, publen-pos, &e);
- pos += ssh2_read_mpint(pubblob+pos, publen-pos, &n);
- pos = 0;
- pos += ssh2_read_mpint(privblob+pos, privlen-pos, &d);
- pos += ssh2_read_mpint(privblob+pos, privlen-pos, &p);
- pos += ssh2_read_mpint(privblob+pos, privlen-pos, &q);
- pos += ssh2_read_mpint(privblob+pos, privlen-pos, &iqmp);
+ /*
+ * These blobs were generated from inside PuTTY, so we needn't
+ * treat them as untrusted.
+ */
+ pos = 4 + GET_32BIT(pubblob);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &e);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &n);
+ pos = 0;
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &d);
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &p);
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &q);
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &iqmp);
+
+ assert(e.start && iqmp.start); /* can't go wrong */
+
+ /* We also need d mod (p-1) and d mod (q-1). */
+ bd = bignum_from_bytes(d.start, d.bytes);
+ bp = bignum_from_bytes(p.start, p.bytes);
+ bq = bignum_from_bytes(q.start, q.bytes);
+ decbn(bp);
+ decbn(bq);
+ bdmp1 = bigmod(bd, bp);
+ bdmq1 = bigmod(bd, bq);
+ freebn(bd);
+ freebn(bp);
+ freebn(bq);
+
+ dmp1.bytes = (bignum_bitcount(bdmp1)+8)/8;
+ dmq1.bytes = (bignum_bitcount(bdmq1)+8)/8;
+ sparelen = dmp1.bytes + dmq1.bytes;
+ spareblob = snewn(sparelen, unsigned char);
+ dmp1.start = spareblob;
+ dmq1.start = spareblob + dmp1.bytes;
+ for (i = 0; i < dmp1.bytes; i++)
+ spareblob[i] = bignum_byte(bdmp1, dmp1.bytes-1 - i);
+ for (i = 0; i < dmq1.bytes; i++)
+ spareblob[i+dmp1.bytes] = bignum_byte(bdmq1, dmq1.bytes-1 - i);
+ freebn(bdmp1);
+ freebn(bdmq1);
+
+ numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
+ numbers[1] = n;
+ numbers[2] = e;
+ numbers[3] = d;
+ numbers[4] = p;
+ numbers[5] = q;
+ numbers[6] = dmp1;
+ numbers[7] = dmq1;
+ numbers[8] = iqmp;
+
+ nnumbers = 9;
+ header = "-----BEGIN RSA PRIVATE KEY-----\n";
+ footer = "-----END RSA PRIVATE KEY-----\n";
+ } else { /* ssh-dss */
+ int pos;
+ struct mpint_pos p, q, g, y, x;
- assert(e.start && iqmp.start); /* can't go wrong */
+ /*
+ * These blobs were generated from inside PuTTY, so we needn't
+ * treat them as untrusted.
+ */
+ pos = 4 + GET_32BIT(pubblob);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &p);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &q);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &g);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &y);
+ pos = 0;
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &x);
+
+ assert(y.start && x.start); /* can't go wrong */
+
+ numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
+ numbers[1] = p;
+ numbers[2] = q;
+ numbers[3] = g;
+ numbers[4] = y;
+ numbers[5] = x;
+
+ nnumbers = 6;
+ header = "-----BEGIN DSA PRIVATE KEY-----\n";
+ footer = "-----END DSA PRIVATE KEY-----\n";
+ }
- /* We also need d mod (p-1) and d mod (q-1). */
- bd = bignum_from_bytes(d.start, d.bytes);
- bp = bignum_from_bytes(p.start, p.bytes);
- bq = bignum_from_bytes(q.start, q.bytes);
- decbn(bp);
- decbn(bq);
- bdmp1 = bigmod(bd, bp);
- bdmq1 = bigmod(bd, bq);
- freebn(bd);
- freebn(bp);
- freebn(bq);
-
- dmp1.bytes = (bignum_bitcount(bdmp1)+8)/8;
- dmq1.bytes = (bignum_bitcount(bdmq1)+8)/8;
- sparelen = dmp1.bytes + dmq1.bytes;
- spareblob = snewn(sparelen, unsigned char);
- dmp1.start = spareblob;
- dmq1.start = spareblob + dmp1.bytes;
- for (i = 0; i < dmp1.bytes; i++)
- spareblob[i] = bignum_byte(bdmp1, dmp1.bytes-1 - i);
- for (i = 0; i < dmq1.bytes; i++)
- spareblob[i+dmp1.bytes] = bignum_byte(bdmq1, dmq1.bytes-1 - i);
- freebn(bdmp1);
- freebn(bdmq1);
-
- numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
- numbers[1] = n;
- numbers[2] = e;
- numbers[3] = d;
- numbers[4] = p;
- numbers[5] = q;
- numbers[6] = dmp1;
- numbers[7] = dmq1;
- numbers[8] = iqmp;
-
- nnumbers = 9;
- header = "-----BEGIN RSA PRIVATE KEY-----\n";
- footer = "-----END RSA PRIVATE KEY-----\n";
- } else if (key->alg == &ssh_dss) {
- int pos;
- struct mpint_pos p, q, g, y, x;
+ /*
+ * Now count up the total size of the ASN.1 encoded integers,
+ * so as to determine the length of the containing SEQUENCE.
+ */
+ len = 0;
+ for (i = 0; i < nnumbers; i++) {
+ len += ber_write_id_len(NULL, 2, numbers[i].bytes, 0);
+ len += numbers[i].bytes;
+ }
+ seqlen = len;
+ /* Now add on the SEQUENCE header. */
+ len += ber_write_id_len(NULL, 16, seqlen, ASN1_CONSTRUCTED);
- pos = 4 + GET_32BIT(pubblob);
- pos += ssh2_read_mpint(pubblob+pos, publen-pos, &p);
- pos += ssh2_read_mpint(pubblob+pos, publen-pos, &q);
- pos += ssh2_read_mpint(pubblob+pos, publen-pos, &g);
- pos += ssh2_read_mpint(pubblob+pos, publen-pos, &y);
+ /*
+ * Now we know how big outblob needs to be. Allocate it.
+ */
+ outblob = snewn(len, unsigned char);
+
+ /*
+ * And write the data into it.
+ */
pos = 0;
- pos += ssh2_read_mpint(privblob+pos, privlen-pos, &x);
+ pos += ber_write_id_len(outblob+pos, 16, seqlen, ASN1_CONSTRUCTED);
+ for (i = 0; i < nnumbers; i++) {
+ pos += ber_write_id_len(outblob+pos, 2, numbers[i].bytes, 0);
+ memcpy(outblob+pos, numbers[i].start, numbers[i].bytes);
+ pos += numbers[i].bytes;
+ }
+ } else if (key->alg == &ssh_ecdsa_nistp256 ||
+ key->alg == &ssh_ecdsa_nistp384 ||
+ key->alg == &ssh_ecdsa_nistp521) {
+ unsigned char *oid;
+ int oidlen;
+ int pointlen;
- assert(y.start && x.start); /* can't go wrong */
+ /*
+ * Structure of asn1:
+ * SEQUENCE
+ * INTEGER 1
+ * OCTET STRING (private key)
+ * [0]
+ * OID (curve)
+ * [1]
+ * BIT STRING (0x00 public key point)
+ */
+ switch (((struct ec_key *)key->data)->publicKey.curve->fieldBits) {
+ case 256:
+ /* OID: 1.2.840.10045.3.1.7 (ansiX9p256r1) */
+ oid = nistp256_oid;
+ oidlen = nistp256_oid_len;
+ pointlen = 32 * 2;
+ break;
+ case 384:
+ /* OID: 1.3.132.0.34 (secp384r1) */
+ oid = nistp384_oid;
+ oidlen = nistp384_oid_len;
+ pointlen = 48 * 2;
+ break;
+ case 521:
+ /* OID: 1.3.132.0.35 (secp521r1) */
+ oid = nistp521_oid;
+ oidlen = nistp521_oid_len;
+ pointlen = 66 * 2;
+ break;
+ default:
+ assert(0);
+ }
- numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
- numbers[1] = p;
- numbers[2] = q;
- numbers[3] = g;
- numbers[4] = y;
- numbers[5] = x;
+ len = ber_write_id_len(NULL, 2, 1, 0);
+ len += 1;
+ len += ber_write_id_len(NULL, 4, privlen - 4, 0);
+ len+= privlen - 4;
+ len += ber_write_id_len(NULL, 0, oidlen +
+ ber_write_id_len(NULL, 6, oidlen, 0),
+ ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
+ len += ber_write_id_len(NULL, 6, oidlen, 0);
+ len += oidlen;
+ len += ber_write_id_len(NULL, 1, 2 + pointlen +
+ ber_write_id_len(NULL, 3, 2 + pointlen, 0),
+ ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
+ len += ber_write_id_len(NULL, 3, 2 + pointlen, 0);
+ len += 2 + pointlen;
+
+ seqlen = len;
+ len += ber_write_id_len(NULL, 16, seqlen, ASN1_CONSTRUCTED);
+
+ outblob = snewn(len, unsigned char);
+ assert(outblob);
- nnumbers = 6;
- header = "-----BEGIN DSA PRIVATE KEY-----\n";
- footer = "-----END DSA PRIVATE KEY-----\n";
+ pos = 0;
+ pos += ber_write_id_len(outblob+pos, 16, seqlen, ASN1_CONSTRUCTED);
+ pos += ber_write_id_len(outblob+pos, 2, 1, 0);
+ outblob[pos++] = 1;
+ pos += ber_write_id_len(outblob+pos, 4, privlen - 4, 0);
+ memcpy(outblob+pos, privblob + 4, privlen - 4);
+ pos += privlen - 4;
+ pos += ber_write_id_len(outblob+pos, 0, oidlen +
+ ber_write_id_len(NULL, 6, oidlen, 0),
+ ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
+ pos += ber_write_id_len(outblob+pos, 6, oidlen, 0);
+ memcpy(outblob+pos, oid, oidlen);
+ pos += oidlen;
+ pos += ber_write_id_len(outblob+pos, 1, 2 + pointlen +
+ ber_write_id_len(NULL, 3, 2 + pointlen, 0),
+ ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
+ pos += ber_write_id_len(outblob+pos, 3, 2 + pointlen, 0);
+ outblob[pos++] = 0;
+ memcpy(outblob+pos, pubblob+39, 1 + pointlen);
+ pos += 1 + pointlen;
+
+ header = "-----BEGIN EC PRIVATE KEY-----\n";
+ footer = "-----END EC PRIVATE KEY-----\n";
} else {
assert(0); /* zoinks! */
exit(1); /* XXX: GCC doesn't understand assert() on some systems. */
}
- /*
- * Now count up the total size of the ASN.1 encoded integers,
- * so as to determine the length of the containing SEQUENCE.
- */
- len = 0;
- for (i = 0; i < nnumbers; i++) {
- len += ber_write_id_len(NULL, 2, numbers[i].bytes, 0);
- len += numbers[i].bytes;
- }
- seqlen = len;
- /* Now add on the SEQUENCE header. */
- len += ber_write_id_len(NULL, 16, seqlen, ASN1_CONSTRUCTED);
- /* Round up to the cipher block size, ensuring we have at least one
- * byte of padding (see below). */
- outlen = len;
- if (passphrase)
- outlen = (outlen+8) &~ 7;
-
- /*
- * Now we know how big outblob needs to be. Allocate it.
- */
- outblob = snewn(outlen, unsigned char);
-
- /*
- * And write the data into it.
- */
- pos = 0;
- pos += ber_write_id_len(outblob+pos, 16, seqlen, ASN1_CONSTRUCTED);
- for (i = 0; i < nnumbers; i++) {
- pos += ber_write_id_len(outblob+pos, 2, numbers[i].bytes, 0);
- memcpy(outblob+pos, numbers[i].start, numbers[i].bytes);
- pos += numbers[i].bytes;
- }
-
- /*
- * Padding on OpenSSH keys is deterministic. The number of
- * padding bytes is always more than zero, and always at most
- * the cipher block length. The value of each padding byte is
- * equal to the number of padding bytes. So a plaintext that's
- * an exact multiple of the block size will be padded with 08
- * 08 08 08 08 08 08 08 (assuming a 64-bit block cipher); a
- * plaintext one byte less than a multiple of the block size
- * will be padded with just 01.
- *
- * This enables the OpenSSL key decryption function to strip
- * off the padding algorithmically and return the unpadded
- * plaintext to the next layer: it looks at the final byte, and
- * then expects to find that many bytes at the end of the data
- * with the same value. Those are all removed and the rest is
- * returned.
- */
- assert(pos == len);
- while (pos < outlen) {
- outblob[pos++] = outlen - len;
- }
-
/*
* Encrypt the key.
*
* old-style 3DES.
*/
if (passphrase) {
+ struct MD5Context md5c;
+ unsigned char keybuf[32];
+
+ /*
+ * Round up to the cipher block size, ensuring we have at
+ * least one byte of padding (see below).
+ */
+ outlen = (len+8) &~ 7;
+ {
+ unsigned char *tmp = snewn(outlen, unsigned char);
+ memcpy(tmp, outblob, len);
+ smemclr(outblob, len);
+ sfree(outblob);
+ outblob = tmp;
+ }
+
+ /*
+ * Padding on OpenSSH keys is deterministic. The number of
+ * padding bytes is always more than zero, and always at most
+ * the cipher block length. The value of each padding byte is
+ * equal to the number of padding bytes. So a plaintext that's
+ * an exact multiple of the block size will be padded with 08
+ * 08 08 08 08 08 08 08 (assuming a 64-bit block cipher); a
+ * plaintext one byte less than a multiple of the block size
+ * will be padded with just 01.
+ *
+ * This enables the OpenSSL key decryption function to strip
+ * off the padding algorithmically and return the unpadded
+ * plaintext to the next layer: it looks at the final byte, and
+ * then expects to find that many bytes at the end of the data
+ * with the same value. Those are all removed and the rest is
+ * returned.
+ */
+ assert(pos == len);
+ while (pos < outlen) {
+ outblob[pos++] = outlen - len;
+ }
+
/*
* Invent an iv. Then derive encryption key from passphrase
* and iv/salt:
* - block C would be MD5(B || passphrase || iv) and so on
* - encryption key is the first N bytes of A || B
*/
- struct MD5Context md5c;
- unsigned char keybuf[32];
-
for (i = 0; i < 8; i++) iv[i] = random_byte();
MD5Init(&md5c);
*/
des3_encrypt_pubkey_ossh(keybuf, iv, outblob, outlen);
- memset(&md5c, 0, sizeof(md5c));
- memset(keybuf, 0, sizeof(keybuf));
+ smemclr(&md5c, sizeof(md5c));
+ smemclr(keybuf, sizeof(keybuf));
+ } else {
+ /*
+ * If no encryption, the blob has exactly its original
+ * cleartext size.
+ */
+ outlen = len;
}
/*
* And save it. We'll use Unix line endings just in case it's
* subsequently transferred in binary mode.
*/
- fp = f_open(*filename, "wb", TRUE); /* ensure Unix line endings */
+ fp = f_open(filename, "wb", TRUE); /* ensure Unix line endings */
if (!fp)
goto error;
fputs(header, fp);
error:
if (outblob) {
- memset(outblob, 0, outlen);
+ smemclr(outblob, outlen);
sfree(outblob);
}
if (spareblob) {
- memset(spareblob, 0, sparelen);
+ smemclr(spareblob, sparelen);
sfree(spareblob);
}
if (privblob) {
- memset(privblob, 0, privlen);
+ smemclr(privblob, privlen);
sfree(privblob);
}
if (pubblob) {
- memset(pubblob, 0, publen);
+ smemclr(pubblob, publen);
sfree(pubblob);
}
return ret;
ret->keyblob = NULL;
ret->keyblob_len = ret->keyblob_size = 0;
- fp = f_open(*filename, "r", FALSE);
+ fp = f_open(filename, "r", FALSE);
if (!fp) {
errmsg = "unable to open key file";
goto error;
errmsg = "file does not begin with ssh.com key header";
goto error;
}
- memset(line, 0, strlen(line));
+ smemclr(line, strlen(line));
sfree(line);
line = NULL;
goto error;
}
strip_crlf(line);
- if (!strcmp(line, "---- END SSH2 ENCRYPTED PRIVATE KEY ----"))
+ if (!strcmp(line, "---- END SSH2 ENCRYPTED PRIVATE KEY ----")) {
+ sfree(line);
+ line = NULL;
break; /* done */
+ }
if ((p = strchr(line, ':')) != NULL) {
if (headers_done) {
errmsg = "header found in body of key data";
len += line2len - 1;
assert(!line[len]);
- memset(line2, 0, strlen(line2));
+ smemclr(line2, strlen(line2));
sfree(line2);
line2 = NULL;
}
p++;
}
}
- memset(line, 0, strlen(line));
+ smemclr(line, strlen(line));
sfree(line);
line = NULL;
}
goto error;
}
+ fclose(fp);
if (errmsg_p) *errmsg_p = NULL;
return ret;
error:
+ if (fp)
+ fclose(fp);
+
if (line) {
- memset(line, 0, strlen(line));
+ smemclr(line, strlen(line));
sfree(line);
line = NULL;
}
if (ret) {
if (ret->keyblob) {
- memset(ret->keyblob, 0, ret->keyblob_size);
+ smemclr(ret->keyblob, ret->keyblob_size);
sfree(ret->keyblob);
}
- memset(ret, 0, sizeof(*ret));
+ smemclr(ret, sizeof(*ret));
sfree(ret);
}
if (errmsg_p) *errmsg_p = errmsg;
struct sshcom_key *key = load_sshcom_key(filename, NULL);
int pos, len, answer;
+ answer = 0;
+
*comment = NULL;
if (!key)
- return 0;
+ goto done;
/*
* Check magic number.
*/
- if (GET_32BIT(key->keyblob) != 0x3f6ff9eb)
- return 0; /* key is invalid */
+ if (GET_32BIT(key->keyblob) != 0x3f6ff9eb) {
+ goto done; /* key is invalid */
+ }
/*
* Find the cipher-type string.
*/
- answer = 0;
pos = 8;
if (key->keyblob_len < pos+4)
goto done; /* key is far too short */
- pos += 4 + GET_32BIT(key->keyblob + pos); /* skip key type */
- if (key->keyblob_len < pos+4)
+ len = toint(GET_32BIT(key->keyblob + pos));
+ if (len < 0 || len > key->keyblob_len - pos - 4)
goto done; /* key is far too short */
- len = GET_32BIT(key->keyblob + pos); /* find cipher-type length */
- if (key->keyblob_len < pos+4+len)
+ pos += 4 + len; /* skip key type */
+ len = toint(GET_32BIT(key->keyblob + pos)); /* find cipher-type length */
+ if (len < 0 || len > key->keyblob_len - pos - 4)
goto done; /* cipher type string is incomplete */
if (len != 4 || 0 != memcmp(key->keyblob + pos + 4, "none", 4))
answer = 1;
done:
- *comment = dupstr(key->comment);
- memset(key->keyblob, 0, key->keyblob_size);
- sfree(key->keyblob);
- memset(key, 0, sizeof(*key));
- sfree(key);
+ if (key) {
+ *comment = dupstr(key->comment);
+ smemclr(key->keyblob, key->keyblob_size);
+ sfree(key->keyblob);
+ smemclr(key, sizeof(*key));
+ sfree(key);
+ } else {
+ *comment = dupstr("");
+ }
return answer;
}
static int sshcom_read_mpint(void *data, int len, struct mpint_pos *ret)
{
- int bits;
- int bytes;
+ unsigned bits, bytes;
unsigned char *d = (unsigned char *) data;
if (len < 4)
*/
pos = 8;
if (key->keyblob_len < pos+4 ||
- (len = GET_32BIT(key->keyblob + pos)) > key->keyblob_len - pos - 4) {
+ (len = toint(GET_32BIT(key->keyblob + pos))) < 0 ||
+ len > key->keyblob_len - pos - 4) {
errmsg = "key blob does not contain a key type string";
goto error;
}
* Determine the cipher type.
*/
if (key->keyblob_len < pos+4 ||
- (len = GET_32BIT(key->keyblob + pos)) > key->keyblob_len - pos - 4) {
+ (len = toint(GET_32BIT(key->keyblob + pos))) < 0 ||
+ len > key->keyblob_len - pos - 4) {
errmsg = "key blob does not contain a cipher type string";
goto error;
}
* Get hold of the encrypted part of the key.
*/
if (key->keyblob_len < pos+4 ||
- (len = GET_32BIT(key->keyblob + pos)) > key->keyblob_len - pos - 4) {
+ (len = toint(GET_32BIT(key->keyblob + pos))) < 0 ||
+ len > key->keyblob_len - pos - 4) {
errmsg = "key blob does not contain actual key data";
goto error;
}
des3_decrypt_pubkey_ossh(keybuf, iv, (unsigned char *)ciphertext,
cipherlen);
- memset(&md5c, 0, sizeof(md5c));
- memset(keybuf, 0, sizeof(keybuf));
+ smemclr(&md5c, sizeof(md5c));
+ smemclr(keybuf, sizeof(keybuf));
/*
* Hereafter we return WRONG_PASSPHRASE for any parsing
/*
* Strip away the containing string to get to the real meat.
*/
- len = GET_32BIT(ciphertext);
+ len = toint(GET_32BIT(ciphertext));
if (len < 0 || len > cipherlen-4) {
errmsg = "containing string was ill-formed";
goto error;
pos += put_mp(blob+pos, p.start, p.bytes);
pos += put_mp(blob+pos, u.start, u.bytes);
privlen = pos - publen;
- } else if (type == DSA) {
+ } else {
struct mpint_pos p, q, g, x, y;
int pos = 4;
+
+ assert(type == DSA); /* the only other option from the if above */
+
if (GET_32BIT(ciphertext) != 0) {
errmsg = "predefined DSA parameters not supported";
goto error;
publen = pos;
pos += put_mp(blob+pos, x.start, x.bytes);
privlen = pos - publen;
- } else
- return NULL;
+ }
assert(privlen > 0); /* should have bombed by now if not */
error:
if (blob) {
- memset(blob, 0, blobsize);
+ smemclr(blob, blobsize);
sfree(blob);
}
- memset(key->keyblob, 0, key->keyblob_size);
+ smemclr(key->keyblob, key->keyblob_size);
sfree(key->keyblob);
- memset(key, 0, sizeof(*key));
+ smemclr(key, sizeof(*key));
sfree(key);
if (errmsg_p) *errmsg_p = errmsg;
return ret;
int pos;
struct mpint_pos n, e, d, p, q, iqmp;
+ /*
+ * These blobs were generated from inside PuTTY, so we needn't
+ * treat them as untrusted.
+ */
pos = 4 + GET_32BIT(pubblob);
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &e);
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &n);
int pos;
struct mpint_pos p, q, g, y, x;
+ /*
+ * These blobs were generated from inside PuTTY, so we needn't
+ * treat them as untrusted.
+ */
pos = 4 + GET_32BIT(pubblob);
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &p);
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &q);
des3_encrypt_pubkey_ossh(keybuf, iv, (unsigned char *)ciphertext,
cipherlen);
- memset(&md5c, 0, sizeof(md5c));
- memset(keybuf, 0, sizeof(keybuf));
+ smemclr(&md5c, sizeof(md5c));
+ smemclr(keybuf, sizeof(keybuf));
}
/*
* And save it. We'll use Unix line endings just in case it's
* subsequently transferred in binary mode.
*/
- fp = f_open(*filename, "wb", TRUE); /* ensure Unix line endings */
+ fp = f_open(filename, "wb", TRUE); /* ensure Unix line endings */
if (!fp)
goto error;
fputs("---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----\n", fp);
error:
if (outblob) {
- memset(outblob, 0, outlen);
+ smemclr(outblob, outlen);
sfree(outblob);
}
if (privblob) {
- memset(privblob, 0, privlen);
+ smemclr(privblob, privlen);
sfree(privblob);
}
if (pubblob) {
- memset(pubblob, 0, publen);
+ smemclr(pubblob, publen);
sfree(pubblob);
}
return ret;
projects / PuTTY.git / blobdiff