From 08558e5b46c4f7f642fb82c4f50e2ee32f9f0d5b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Tue, 4 Nov 2014 14:40:21 +0100 Subject: [PATCH] Fix for the RFC erratum --- library/ssl_tls.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/library/ssl_tls.c b/library/ssl_tls.c index f63550555..4132e47aa 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -1357,17 +1357,18 @@ static int ssl_encrypt_buf( ssl_context *ssl ) * MAC(MAC_write_key, seq_num + * TLSCipherText.type + * TLSCipherText.version + - * TLSCipherText.length + + * length_of( (IV +) ENC(...) ) + * IV + // except for TLS 1.0 * ENC(content + padding + padding_length)); */ - size_t final_len = ssl->out_msglen + ssl->transform_out->maclen; unsigned char pseudo_hdr[13]; memcpy( pseudo_hdr + 0, ssl->out_ctr, 8 ); memcpy( pseudo_hdr + 8, ssl->out_hdr, 3 ); - pseudo_hdr[11] = (unsigned char)( ( final_len >> 8 ) & 0xFF ); - pseudo_hdr[12] = (unsigned char)( ( final_len ) & 0xFF ); + pseudo_hdr[11] = (unsigned char)( ( ssl->out_msglen >> 8 ) & 0xFF ); + pseudo_hdr[12] = (unsigned char)( ( ssl->out_msglen ) & 0xFF ); + + SSL_DEBUG_BUF( 4, "MAC'd meta-data", pseudo_hdr, 13 ); md_hmac_update( &ssl->transform_out->md_ctx_enc, pseudo_hdr, 13 ); md_hmac_update( &ssl->transform_out->md_ctx_enc, @@ -1570,13 +1571,19 @@ static int ssl_decrypt_buf( ssl_context *ssl ) if( mac_order == MAC_CIPHERTEXT ) { unsigned char computed_mac[POLARSSL_SSL_MAX_MAC_SIZE]; + unsigned char pseudo_hdr[13]; dec_msglen -= ssl->transform_in->maclen; ssl->in_msglen -= ssl->transform_in->maclen; - // TODO: adjust for DTLS - md_hmac_update( &ssl->transform_in->md_ctx_dec, - ssl->in_ctr, 13 ); + memcpy( pseudo_hdr + 0, ssl->in_ctr, 8 ); + memcpy( pseudo_hdr + 8, ssl->in_hdr, 3 ); + pseudo_hdr[11] = (unsigned char)( ( ssl->in_msglen >> 8 ) & 0xFF ); + pseudo_hdr[12] = (unsigned char)( ( ssl->in_msglen ) & 0xFF ); + + SSL_DEBUG_BUF( 4, "MAC'd meta-data", pseudo_hdr, 13 ); + + md_hmac_update( &ssl->transform_in->md_ctx_dec, pseudo_hdr, 13 ); md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_iv, ssl->in_msglen ); md_hmac_finish( &ssl->transform_in->md_ctx_dec, computed_mac );