Make cipher used in ssl tickets configurable
diff --git a/include/mbedtls/ssl_ticket.h b/include/mbedtls/ssl_ticket.h
index 42842c5..3612a92 100644
--- a/include/mbedtls/ssl_ticket.h
+++ b/include/mbedtls/ssl_ticket.h
@@ -70,13 +70,20 @@
* \param ctx Context to be set up
* \param f_rng RNG callback function
* \param p_rng RNG callback context
+ * \param cipher AEAD cipher to use for ticket protection, eg
+ * MBEDTLS_CIPHER_AES_256_GCM or MBEDTLS_CIPHER_AES_256_CCM.
* \param lifetime Tickets lifetime in seconds
*
+ * \note It is highly recommended to select a cipher that is at
+ * least as strong as the the strongest ciphersuite
+ * supported. Usually that means a 256-bit key.
+ *
* \return 0 is successful,
* or a specific MBEDTLS_ERR_XXX error code
*/
int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
+ mbedtls_cipher_type_t cipher,
uint32_t lifetime );
/**
diff --git a/library/ssl_ticket.c b/library/ssl_ticket.c
index 9955060..8994cef 100644
--- a/library/ssl_ticket.c
+++ b/library/ssl_ticket.c
@@ -61,10 +61,13 @@
*/
int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
+ mbedtls_cipher_type_t cipher,
uint32_t lifetime )
{
int ret;
unsigned char buf[32];
+ mbedtls_cipher_mode_t mode;
+ size_t key_bits;
ctx->f_rng = f_rng;
ctx->p_rng = p_rng;
@@ -72,19 +75,32 @@
ctx->ticket_lifetime = lifetime;
if( ( ret = mbedtls_cipher_setup( &ctx->cipher,
- mbedtls_cipher_info_from_type(
- MBEDTLS_CIPHER_AES_256_GCM ) ) ) != 0 )
+ mbedtls_cipher_info_from_type( cipher) ) ) != 0 )
{
goto cleanup;
}
+ mode = mbedtls_cipher_get_cipher_mode( &ctx->cipher );
+ if( mode != MBEDTLS_MODE_GCM && mode != MBEDTLS_MODE_CCM )
+ {
+ ret = MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
+ goto cleanup;
+ }
+
+ key_bits = mbedtls_cipher_get_key_size( &ctx->cipher );
+ if( key_bits > 8 * sizeof( buf ) )
+ {
+ ret = MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
+ goto cleanup;
+ }
+
if( ( ret = f_rng( p_rng, buf, sizeof( buf ) ) != 0 ) )
{
goto cleanup;
}
/* With GCM and CCM, same context can encrypt & decrypt */
- if( ( ret = mbedtls_cipher_setkey( &ctx->cipher, buf, 256,
+ if( ( ret = mbedtls_cipher_setkey( &ctx->cipher, buf, key_bits,
MBEDTLS_ENCRYPT ) ) != 0 )
{
goto cleanup;
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 5f66d51..390450b 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -1598,6 +1598,7 @@
{
if( ( ret = mbedtls_ssl_ticket_setup( &ticket_ctx,
mbedtls_ctr_drbg_random, &ctr_drbg,
+ MBEDTLS_CIPHER_AES_256_GCM,
opt.ticket_timeout ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_ticket_setup returned %d\n\n", ret );