CTR_DRBG: add mbedtls_ctr_drbg_update_ret
Deprecate mbedtls_ctr_drbg_update (which returns void) in favor of a
new function mbedtls_ctr_drbg_update_ret which reports error. The old
function is not officially marked as deprecated in this branch because
this is a stable maintenance branch.
diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index fc3188e..d7a9484 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -303,22 +303,36 @@
return( ret );
}
-void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
- const unsigned char *additional, size_t add_len )
+int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
+ const unsigned char *additional,
+ size_t add_len )
{
unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
+ int ret;
- if( add_len > 0 )
- {
- /* MAX_INPUT would be more logical here, but we have to match
- * block_cipher_df()'s limits since we can't propagate errors */
- if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
- add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
+ if( add_len == 0 )
+ return( 0 );
- block_cipher_df( add_input, additional, add_len );
- ctr_drbg_update_internal( ctx, add_input );
- mbedtls_zeroize( add_input, sizeof( add_input ) );
- }
+ if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
+ goto exit;
+ if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
+ goto exit;
+
+exit:
+ mbedtls_zeroize( add_input, sizeof( add_input ) );
+ return( ret );
+}
+
+/* Deprecated function, kept for backward compatibility. */
+void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
+ const unsigned char *additional,
+ size_t add_len )
+{
+ /* MAX_INPUT would be more logical here, but we have to match
+ * block_cipher_df()'s limits since we can't propagate errors */
+ if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
+ add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
+ (void) mbedtls_ctr_drbg_update_ret( ctx, additional, add_len );
}
int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
@@ -514,7 +528,7 @@
if( fread( buf, 1, n, f ) != n )
ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
else
- mbedtls_ctr_drbg_update( ctx, buf, n );
+ ret = mbedtls_ctr_drbg_update_ret( ctx, buf, n );
fclose( f );