diff options
Diffstat (limited to 'crypto/openssl/ssl/s2_srvr.c')
| -rw-r--r-- | crypto/openssl/ssl/s2_srvr.c | 58 |
1 files changed, 47 insertions, 11 deletions
diff --git a/crypto/openssl/ssl/s2_srvr.c b/crypto/openssl/ssl/s2_srvr.c index 59ced3f..18e2813 100644 --- a/crypto/openssl/ssl/s2_srvr.c +++ b/crypto/openssl/ssl/s2_srvr.c @@ -454,9 +454,6 @@ static int get_client_master_key(SSL *s) SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_NO_PRIVATEKEY); return(-1); } - i=ssl_rsa_private_decrypt(s->cert,s->s2->tmp.enc, - &(p[s->s2->tmp.clear]),&(p[s->s2->tmp.clear]), - (s->s2->ssl2_rollback)?RSA_SSLV23_PADDING:RSA_PKCS1_PADDING); is_export=SSL_C_IS_EXPORT(s->session->cipher); @@ -475,23 +472,61 @@ static int get_client_master_key(SSL *s) else ek=5; + /* + * The format of the CLIENT-MASTER-KEY message is + * 1 byte message type + * 3 bytes cipher + * 2-byte clear key length (stored in s->s2->tmp.clear) + * 2-byte encrypted key length (stored in s->s2->tmp.enc) + * 2-byte key args length (IV etc) + * clear key + * encrypted key + * key args + * + * If the cipher is an export cipher, then the encrypted key bytes + * are a fixed portion of the total key (5 or 8 bytes). The size of + * this portion is in |ek|. If the cipher is not an export cipher, + * then the entire key material is encrypted (i.e., clear key length + * must be zero). + */ + if ((!is_export && s->s2->tmp.clear != 0) || + (is_export && s->s2->tmp.clear + ek != EVP_CIPHER_key_length(c))) { + ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR); + SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_BAD_LENGTH); + return -1; + } + /* + * The encrypted blob must decrypt to the encrypted portion of the key. + * Decryption can't be expanding, so if we don't have enough encrypted + * bytes to fit the key in the buffer, stop now. + */ + if ((is_export && s->s2->tmp.enc < ek) || + (!is_export && s->s2->tmp.enc < EVP_CIPHER_key_length(c))) { + ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR); + SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_LENGTH_TOO_SHORT); + return -1; + } + + i = ssl_rsa_private_decrypt(s->cert, s->s2->tmp.enc, + &(p[s->s2->tmp.clear]), + &(p[s->s2->tmp.clear]), + (s->s2->ssl2_rollback) ? RSA_SSLV23_PADDING : + RSA_PKCS1_PADDING); + /* bad decrypt */ #if 1 /* If a bad decrypt, continue with protocol but with a * random master secret (Bleichenbacher attack) */ - if ((i < 0) || - ((!is_export && (i != EVP_CIPHER_key_length(c))) - || (is_export && ((i != ek) || (s->s2->tmp.clear+(unsigned int)i != - (unsigned int)EVP_CIPHER_key_length(c)))))) - { + if ((i < 0) || ((!is_export && i != EVP_CIPHER_key_length(c)) + || (is_export && i != ek))) { ERR_clear_error(); if (is_export) i=ek; else i=EVP_CIPHER_key_length(c); - if (RAND_pseudo_bytes(p,i) <= 0) + if (RAND_pseudo_bytes(&p[s->s2->tmp.clear], i) <= 0) return 0; - } + } #else if (i < 0) { @@ -513,7 +548,8 @@ static int get_client_master_key(SSL *s) } #endif - if (is_export) i+=s->s2->tmp.clear; + if (is_export) + i = EVP_CIPHER_key_length(c); if (i > SSL_MAX_MASTER_KEY_LENGTH) { |
