diff options
| author | Dr. Stephen Henson <steve@openssl.org> | 2013-03-22 21:12:33 +0400 |
|---|---|---|
| committer | Dr. Stephen Henson <steve@openssl.org> | 2013-09-08 16:14:03 +0400 |
| commit | 5e3ff62c345c976cd1ffbcc5e6042f55264977f5 (patch) | |
| tree | 16c9ffcc2468e21f5ee445e440c835857ed94c81 /ssl/s3_pkt.c | |
| parent | 226751ae4a1f3e00021c43399d7bb51a99c22c17 (diff) | |
Experimental encrypt-then-mac support.
Experimental support for encrypt then mac from
draft-gutmann-tls-encrypt-then-mac-02.txt
To enable it set the appropriate extension number (0x10 for the test server)
using e.g. -DTLSEXT_TYPE_encrypt_then_mac=0x10
For non-compliant peers (i.e. just about everything) this should have no
effect.
Diffstat (limited to 'ssl/s3_pkt.c')
| -rw-r--r-- | ssl/s3_pkt.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c index 65b742c119..3f936c0905 100644 --- a/ssl/s3_pkt.c +++ b/ssl/s3_pkt.c @@ -408,6 +408,30 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); /* decrypt in place in 'rr->input' */ rr->data=rr->input; rr->orig_len=rr->length; + /* If in encrypt-then-mac mode calculate mac from encrypted record. + * All the details below are public so no timing details can leak. + */ + if (SSL_USE_ETM(s) && s->read_hash) + { + unsigned char *mac; + mac_size=EVP_MD_CTX_size(s->read_hash); + OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); + if (rr->length < mac_size) + { + al=SSL_AD_DECODE_ERROR; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); + goto f_err; + } + rr->length -= mac_size; + mac = rr->data + rr->length; + i=s->method->ssl3_enc->mac(s,md,0 /* not send */); + if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) + { + al=SSL_AD_BAD_RECORD_MAC; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); + goto f_err; + } + } enc_err = s->method->ssl3_enc->enc(s,0); /* enc_err is: @@ -430,7 +454,7 @@ printf("\n"); /* r->length is now the compressed data plus mac */ if ((sess != NULL) && (s->enc_read_ctx != NULL) && - (EVP_MD_CTX_md(s->read_hash) != NULL)) + (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) { /* s->read_hash != NULL => mac_size != -1 */ unsigned char *mac = NULL; @@ -820,7 +844,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, * from wr->input. Length should be wr->length. * wr->data still points in the wb->buf */ - if (mac_size != 0) + if (!SSL_USE_ETM(s) && mac_size != 0) { if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0) goto err; @@ -840,6 +864,13 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, /* ssl3_enc can only have an error on read */ s->method->ssl3_enc->enc(s,1); + if (SSL_USE_ETM(s) && mac_size != 0) + { + if (s->method->ssl3_enc->mac(s,p + wr->length,1) < 0) + goto err; + wr->length+=mac_size; + } + /* record length after mac and block padding */ s2n(wr->length,plen); |