Add some sanity checks for EVP_CIPHER_meth_new()

Ensure that the nid and key length are non-negative and that the block
size is one of the three sizes 1, 8, or 16 supported by the EVP subsystem.

ok joshua jsing

diff --git a/lib/libcrypto/evp/cipher_method_lib.c b/lib/libcrypto/evp/cipher_method_lib.c
index c3f510f..d393152 100644 (file)
--- a/lib/libcrypto/evp/cipher_method_lib.c
+++ b/lib/libcrypto/evp/cipher_method_lib.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: cipher_method_lib.c,v 1.10 2023/07/07 19:37:53 beck Exp $ */
+/*     $OpenBSD: cipher_method_lib.c,v 1.11 2023/12/20 14:05:58 tb Exp $ */
 /*
  * Written by Richard Levitte (levitte@openssl.org) for the OpenSSL project
  * 2015.
@@ -68,6 +68,13 @@ EVP_CIPHER_meth_new(int cipher_type, int block_size, int key_len)
 {
        EVP_CIPHER *cipher;
 
+       if (cipher_type < 0 || key_len < 0)
+               return NULL;
+
+       /* EVP_CipherInit() will fail for any other value. */
+       if (block_size != 1 && block_size != 8 && block_size != 16)
+               return NULL;
+
        if ((cipher = calloc(1, sizeof(*cipher))) == NULL)
                return NULL;