Fix gcc -O3 warnings
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/cmac.c b/library/cmac.c
index cd3bd3a..c4f0b54 100644
--- a/library/cmac.c
+++ b/library/cmac.c
@@ -224,6 +224,10 @@
block_size = mbedtls_cipher_info_get_block_size(ctx->cipher_info);
state = ctx->cmac_ctx->state;
+ /* Without the MBEDTLS_ASSUME below, gcc -O3 will generate a warning of the form
+ * error: writing 16 bytes into a region of size 0 [-Werror=stringop-overflow=] */
+ MBEDTLS_ASSUME(block_size <= MBEDTLS_CMAC_MAX_BLOCK_SIZE);
+
/* Is there data still to process from the last call, that's greater in
* size than a block? */
if (cmac_ctx->unprocessed_len > 0 &&
@@ -291,6 +295,7 @@
cmac_ctx = ctx->cmac_ctx;
block_size = mbedtls_cipher_info_get_block_size(ctx->cipher_info);
+ MBEDTLS_ASSUME(block_size <= MBEDTLS_CMAC_MAX_BLOCK_SIZE); // silence GCC warning
state = cmac_ctx->state;
mbedtls_platform_zeroize(K1, sizeof(K1));