Ensure we never use a partially initialised CMAC_CTX
If the CMAC_CTX is partially initialised then we make a note of this so
that future operations will fail if the initialisation has not been
completed.
@@ -125,12 +125,18 @@ int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,
return 1;
}
/* Initialise context */
- if (cipher && !EVP_EncryptInit_ex(ctx->cctx, cipher, impl, NULL, NULL))
+ if (cipher != NULL) {
+ /* Ensure we can't use this ctx until we also have a key */
+ ctx->nlast_block = -1;
+ if (!EVP_EncryptInit_ex(ctx->cctx, cipher, impl, NULL, NULL))
return 0;
+ }
/* Non-NULL key means initialisation complete */
- if (key) {
+ if (key != NULL) {
int bl;
+ /* If anything fails then ensure we can't use this ctx */
+ ctx->nlast_block = -1;
if (!EVP_CIPHER_CTX_cipher(ctx->cctx))
return 0;
if (!EVP_CIPHER_CTX_set_key_length(ctx->cctx, keylen))
