Remove key length field from ssl_transform
The `ssl_transform` security parameter structure contains opaque
cipher contexts for use by the record encryption/decryption functions
`ssl_decrypt_buf`/`ssl_encrypt_buf`, while the underlying key material
is configured once in `ssl_derive_keys` and is not explicitly dealt with
anymore afterwards. In particular, the key length is not needed
explicitly by the encryption/decryption functions but is nonetheless
stored in an explicit yet superfluous `keylen` field in `ssl_transform`.
This commit removes this field.
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 5dde239..d1eeda0 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -465,7 +465,6 @@
*/
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
/*!< Chosen cipersuite_info */
- unsigned int keylen; /*!< symmetric key length (bytes) */
size_t minlen; /*!< min. ciphertext length */
size_t ivlen; /*!< IV length */
size_t fixed_ivlen; /*!< Fixed part of IV (AEAD) */
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index abe2450..ad8f024 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -739,6 +739,7 @@
size_t mac_key_len;
size_t iv_copy_len;
size_t taglen = 0;
+ unsigned keylen;
const mbedtls_cipher_info_t *cipher_info;
const mbedtls_md_info_t *md_info;
@@ -992,7 +993,7 @@
* Determine the appropriate key, IV and MAC length.
*/
- transform->keylen = cipher_info->key_bitlen / 8;
+ keylen = cipher_info->key_bitlen / 8;
if( cipher_info->mode == MBEDTLS_MODE_GCM ||
cipher_info->mode == MBEDTLS_MODE_CCM ||
@@ -1104,9 +1105,11 @@
}
}
- MBEDTLS_SSL_DEBUG_MSG( 3, ( "keylen: %d, minlen: %d, ivlen: %d, maclen: %d",
- transform->keylen, transform->minlen, transform->ivlen,
- transform->maclen ) );
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "keylen: %u, minlen: %u, ivlen: %u, maclen: %u",
+ (unsigned) keylen,
+ (unsigned) transform->minlen,
+ (unsigned) transform->ivlen,
+ (unsigned) transform->maclen ) );
/*
* Finally setup the cipher contexts, IVs and MAC secrets.
@@ -1115,7 +1118,7 @@
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
{
key1 = keyblk + mac_key_len * 2;
- key2 = keyblk + mac_key_len * 2 + transform->keylen;
+ key2 = keyblk + mac_key_len * 2 + keylen;
mac_enc = keyblk;
mac_dec = keyblk + mac_key_len;
@@ -1125,8 +1128,8 @@
*/
iv_copy_len = ( transform->fixed_ivlen ) ?
transform->fixed_ivlen : transform->ivlen;
- memcpy( transform->iv_enc, key2 + transform->keylen, iv_copy_len );
- memcpy( transform->iv_dec, key2 + transform->keylen + iv_copy_len,
+ memcpy( transform->iv_enc, key2 + keylen, iv_copy_len );
+ memcpy( transform->iv_dec, key2 + keylen + iv_copy_len,
iv_copy_len );
}
else
@@ -1134,7 +1137,7 @@
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
{
- key1 = keyblk + mac_key_len * 2 + transform->keylen;
+ key1 = keyblk + mac_key_len * 2 + keylen;
key2 = keyblk + mac_key_len * 2;
mac_enc = keyblk + mac_key_len;
@@ -1145,8 +1148,8 @@
*/
iv_copy_len = ( transform->fixed_ivlen ) ?
transform->fixed_ivlen : transform->ivlen;
- memcpy( transform->iv_dec, key1 + transform->keylen, iv_copy_len );
- memcpy( transform->iv_enc, key1 + transform->keylen + iv_copy_len,
+ memcpy( transform->iv_dec, key1 + keylen, iv_copy_len );
+ memcpy( transform->iv_enc, key1 + keylen + iv_copy_len,
iv_copy_len );
}
else
@@ -1196,7 +1199,7 @@
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_init()" ) );
- if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, transform->keylen,
+ if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, keylen,
transform->iv_enc, transform->iv_dec,
iv_copy_len,
mac_enc, mac_dec,
@@ -1213,7 +1216,7 @@
{
ssl->conf->f_export_keys( ssl->conf->p_export_keys,
session->master, keyblk,
- mac_key_len, transform->keylen,
+ mac_key_len, keylen,
iv_copy_len );
}
#endif
