From c4a190bb0f3f21d3a5747a5171af0067ae0cc5eb Mon Sep 17 00:00:00 2001
From: Hanno Becker <hanno.becker@arm.com>
Date: Wed, 8 May 2019 18:15:21 +0100
Subject: [PATCH] Add length of CID to additional data used for record
protection
Quoting the CID draft 04:
- Block Ciphers:
MAC(MAC_write_key, seq_num +
tls12_cid + // New input
DTLSPlaintext.version +
cid + // New input
cid_length + // New input
length_of_DTLSInnerPlaintext + // New input
DTLSInnerPlaintext.content + // New input
DTLSInnerPlaintext.real_type + // New input
DTLSInnerPlaintext.zeros // New input
)
And similar for AEAD and Encrypt-then-MAC.
---
library/ssl_tls.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 187c28a9d..385631a23 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2050,7 +2050,7 @@ static int ssl_cid_parse_inner_plaintext( unsigned char const *content,
#endif /* MBEDTLS_SSL_CID */
/* `add_data` must have size 13 Bytes if the CID extension is disabled,
- * and 13 + CID-length Bytes if the CID extension is enabled. */
+ * and 13 + 1 + CID-length Bytes if the CID extension is enabled. */
static void ssl_extract_add_data_from_record( unsigned char* add_data,
size_t *add_data_len,
mbedtls_record *rec )
@@ -2077,9 +2077,10 @@ static void ssl_extract_add_data_from_record( unsigned char* add_data,
#if defined(MBEDTLS_SSL_CID)
memcpy( add_data + 11, rec->cid, rec->cid_len );
- add_data[11 + rec->cid_len + 0] = ( rec->data_len >> 8 ) & 0xFF;
- add_data[11 + rec->cid_len + 1] = ( rec->data_len >> 0 ) & 0xFF;
- *add_data_len = 13 + rec->cid_len;
+ add_data[11 + rec->cid_len + 0] = rec->cid_len;
+ add_data[11 + rec->cid_len + 1] = ( rec->data_len >> 8 ) & 0xFF;
+ add_data[11 + rec->cid_len + 2] = ( rec->data_len >> 0 ) & 0xFF;
+ *add_data_len = 13 + 1 + rec->cid_len;
#else /* MBEDTLS_SSL_CID */
add_data[11 + 0] = ( rec->data_len >> 8 ) & 0xFF;
add_data[11 + 1] = ( rec->data_len >> 0 ) & 0xFF;
@@ -2096,7 +2097,7 @@ int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_cipher_mode_t mode;
int auth_done = 0;
unsigned char * data;
- unsigned char add_data[13 + MBEDTLS_SSL_CID_LEN_MAX ];
+ unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_LEN_MAX ];
size_t add_data_len;
size_t post_avail;
@@ -2536,7 +2537,7 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context *ssl,
size_t padlen = 0, correct = 1;
#endif
unsigned char* data;
- unsigned char add_data[13 + MBEDTLS_SSL_CID_LEN_MAX ];
+ unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_LEN_MAX ];
size_t add_data_len;
#if !defined(MBEDTLS_DEBUG_C)