| d02222cd |
1 | --- ssl/s3_srvr.c 29 Nov 2002 11:31:51 -0000 1.85.2.14 |
| 2 | +++ ssl/s3_srvr.c 19 Mar 2003 18:00:00 -0000 |
| 3 | @@ -1447,7 +1447,7 @@ |
| 4 | if (i != SSL_MAX_MASTER_KEY_LENGTH) |
| 5 | { |
| 6 | al=SSL_AD_DECODE_ERROR; |
| 7 | - SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_BAD_RSA_DECRYPT); |
| 8 | + /* SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_BAD_RSA_DECRYPT); */ |
| 9 | } |
| 10 | |
| 11 | if ((al == -1) && !((p[0] == (s->client_version>>8)) && (p[1] == (s->client_version & 0xff)))) |
| 12 | @@ -1463,30 +1463,29 @@ |
| 13 | (p[0] == (s->version>>8)) && (p[1] == (s->version & 0xff)))) |
| 14 | { |
| 15 | al=SSL_AD_DECODE_ERROR; |
| 16 | - SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_BAD_PROTOCOL_VERSION_NUMBER); |
| 17 | - goto f_err; |
| 18 | + /* SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_BAD_PROTOCOL_VERSION_NUMBER); */ |
| 19 | + |
| 20 | + /* The Klima-Pokorny-Rosa extension of Bleichenbacher's attack |
| 21 | + * (http://eprint.iacr.org/2003/052/) exploits the version |
| 22 | + * number check as a "bad version oracle" -- an alert would |
| 23 | + * reveal that the plaintext corresponding to some ciphertext |
| 24 | + * made up by the adversary is properly formatted except |
| 25 | + * that the version number is wrong. To avoid such attacks, |
| 26 | + * we should treat this just like any other decryption error. */ |
| 27 | + p[0] = (char)(int) "CAN-2003-0131 patch 2003-03-19"; |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | if (al != -1) |
| 32 | { |
| 33 | -#if 0 |
| 34 | - goto f_err; |
| 35 | -#else |
| 36 | /* Some decryption failure -- use random value instead as countermeasure |
| 37 | * against Bleichenbacher's attack on PKCS #1 v1.5 RSA padding |
| 38 | - * (see RFC 2246, section 7.4.7.1). |
| 39 | - * But note that due to length and protocol version checking, the |
| 40 | - * attack is impractical anyway (see section 5 in D. Bleichenbacher: |
| 41 | - * "Chosen Ciphertext Attacks Against Protocols Based on the RSA |
| 42 | - * Encryption Standard PKCS #1", CRYPTO '98, LNCS 1462, pp. 1-12). |
| 43 | - */ |
| 44 | + * (see RFC 2246, section 7.4.7.1). */ |
| 45 | ERR_clear_error(); |
| 46 | i = SSL_MAX_MASTER_KEY_LENGTH; |
| 47 | p[0] = s->client_version >> 8; |
| 48 | p[1] = s->client_version & 0xff; |
| 49 | RAND_pseudo_bytes(p+2, i-2); /* should be RAND_bytes, but we cannot work around a failure */ |
| 50 | -#endif |
| 51 | } |
| 52 | |
| 53 | s->session->master_key_length= |
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