diff options
author | Ben Laurie <ben@links.org> | 2013-01-28 17:33:18 +0000 |
---|---|---|
committer | Ben Laurie <ben@links.org> | 2013-01-28 17:33:18 +0000 |
commit | 6cb19b7681f600b2f165e4adc57547b097b475fd (patch) | |
tree | f0bf30e675c0bbaa29be28db7febd92f1a678936 | |
parent | e130841bccfc0bb9da254dc84e23bc6a1c78a64e (diff) |
Don't crash when processing a zero-length, TLS >= 1.1 record.
The previous CBC patch was bugged in that there was a path through enc()
in s3_pkt.c/d1_pkt.c which didn't set orig_len. orig_len would be left
at the previous value which could suggest that the packet was a
sufficient length when it wasn't.
-rw-r--r-- | ssl/d1_enc.c | 1 | ||||
-rw-r--r-- | ssl/d1_pkt.c | 1 | ||||
-rw-r--r-- | ssl/s3_enc.c | 11 | ||||
-rw-r--r-- | ssl/s3_pkt.c | 5 | ||||
-rw-r--r-- | ssl/t1_enc.c | 13 |
5 files changed, 24 insertions, 7 deletions
diff --git a/ssl/d1_enc.c b/ssl/d1_enc.c index c13b495a08..da42348b3d 100644 --- a/ssl/d1_enc.c +++ b/ssl/d1_enc.c @@ -245,7 +245,6 @@ int dtls1_enc(SSL *s, int send) } #endif /* KSSL_DEBUG */ - rec->orig_len = rec->length; if ((bs != 1) && !send) return tls1_cbc_remove_padding(s, rec, bs, mac_size); } diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c index 5e2c56c983..4763d5cd1f 100644 --- a/ssl/d1_pkt.c +++ b/ssl/d1_pkt.c @@ -414,6 +414,7 @@ dtls1_process_record(SSL *s) /* decrypt in place in 'rr->input' */ rr->data=rr->input; + rr->orig_len=rr->length; enc_err = s->method->ssl3_enc->enc(s,0); if (enc_err <= 0) diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c index 33a6d5264c..e963efd47f 100644 --- a/ssl/s3_enc.c +++ b/ssl/s3_enc.c @@ -466,6 +466,15 @@ void ssl3_cleanup_key_block(SSL *s) s->s3->tmp.key_block_length=0; } +/* ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. + * + * Returns: + * 0: (in non-constant time) if the record is publically invalid (i.e. too + * short etc). + * 1: if the record's padding is valid / the encryption was successful. + * -1: if the record's padding is invalid or, if sending, an internal error + * occured. + */ int ssl3_enc(SSL *s, int send) { SSL3_RECORD *rec; @@ -532,8 +541,6 @@ int ssl3_enc(SSL *s, int send) EVP_Cipher(ds,rec->data,rec->input,l); - rec->orig_len = rec->length; - if (EVP_MD_CTX_md(s->read_hash) != NULL) mac_size = EVP_MD_CTX_size(s->read_hash); if ((bs != 1) && !send) diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c index 57a0b74556..dd98e698bf 100644 --- a/ssl/s3_pkt.c +++ b/ssl/s3_pkt.c @@ -399,8 +399,13 @@ 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; enc_err = s->method->ssl3_enc->enc(s,0); + /* enc_err is: + * 0: (in non-constant time) if the record is publically invalid. + * 1: if the padding is valid + * -1: if the padding is invalid */ if (enc_err == 0) { /* SSLerr() and ssl3_send_alert() have been called */ diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c index a46c42143c..67a1fea887 100644 --- a/ssl/t1_enc.c +++ b/ssl/t1_enc.c @@ -667,6 +667,15 @@ err: return(ret); } +/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. + * + * Returns: + * 0: (in non-constant time) if the record is publically invalid (i.e. too + * short etc). + * 1: if the record's padding is valid / the encryption was successful. + * -1: if the record's padding/AEAD-authenticator is invalid or, if sending, + * an internal error occured. + */ int tls1_enc(SSL *s, int send) { SSL3_RECORD *rec; @@ -817,8 +826,6 @@ int tls1_enc(SSL *s, int send) { if (l == 0 || l%bs != 0) { - if (s->version >= TLS1_1_VERSION) - return -1; SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED); return 0; @@ -846,8 +853,6 @@ int tls1_enc(SSL *s, int send) } #endif /* KSSL_DEBUG */ - rec->orig_len = rec->length; - ret = 1; if (EVP_MD_CTX_md(s->read_hash) != NULL) mac_size = EVP_MD_CTX_size(s->read_hash); |