crypto: testmgr - support checking skcipher output IV

Allow skcipher test vectors to declare the value the IV buffer should be
updated to at the end of the encryption or decryption operation.

(This check actually used to be supported in testmgr, but it was never
used and therefore got removed except for the AES-Keywrap special case.
But it will be used by CBC and CTR now, so re-add it.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/testmgr.c

@@ -1542,7 +1542,9 @@ static int test_skcipher_vec_cfg(const char *driver, int enc,
 	if (ivsize) {
 		if (WARN_ON(ivsize > MAX_IVLEN))
 			return -EINVAL;
-		if (vec->iv && !(vec->generates_iv && enc))
+		if (vec->generates_iv && !enc)
+			memcpy(iv, vec->iv_out, ivsize);
+		else if (vec->iv)
 			memcpy(iv, vec->iv, ivsize);
 		else
 			memset(iv, 0, ivsize);
@@ -1635,7 +1637,7 @@ static int test_skcipher_vec_cfg(const char *driver, int enc,
 	}
 
 	/* If applicable, check that the algorithm generated the correct IV */
-	if (vec->generates_iv && enc && memcmp(iv, vec->iv, ivsize) != 0) {
+	if (vec->iv_out && memcmp(iv, vec->iv_out, ivsize) != 0) {
 		pr_err("alg: skcipher: %s %s test failed (wrong output IV) on test vector %u, cfg=\"%s\"\n",
 		       driver, op, vec_num, cfg->name);
 		hexdump(iv, ivsize);

crypto/testmgr.h

@@ -47,7 +47,8 @@ struct hash_testvec {
  * cipher_testvec:	structure to describe a symmetric cipher test
  * @key:	Pointer to key
  * @klen:	Length of @key in bytes
- * @iv:		Pointer to IV (optional for some ciphers)
+ * @iv:		Pointer to IV.  If NULL, an all-zeroes IV is used.
+ * @iv_out:	Pointer to output IV, if applicable for the cipher.
  * @ptext:	Pointer to plaintext
  * @ctext:	Pointer to ciphertext
  * @len:	Length of @ptext and @ctext in bytes
@@ -55,12 +56,13 @@ struct hash_testvec {
  * @wk:		Does the test need CRYPTO_TFM_REQ_FORBID_WEAK_KEYS?
  * 		( e.g. test needs to fail due to a weak key )
  * @fips_skip:	Skip the test vector in FIPS mode
- * @generates_iv: Encryption should ignore the given IV, and output @iv.
- *		  Decryption takes @iv.  Needed for AES Keywrap ("kw(aes)").
+ * @generates_iv: Encryption should ignore the given IV, and output @iv_out.
+ *		  Decryption takes @iv_out.  Needed for AES Keywrap ("kw(aes)").
  */
 struct cipher_testvec {
 	const char *key;
 	const char *iv;
+	const char *iv_out;
 	const char *ptext;
 	const char *ctext;
 	bool fail;
@@ -21771,7 +21773,7 @@ static const struct cipher_testvec aes_kw_tv_template[] = {
 		.ctext	= "\xf6\x85\x94\x81\x6f\x64\xca\xa3"
 			  "\xf5\x6f\xab\xea\x25\x48\xf5\xfb",
 		.len	= 16,
-		.iv	= "\x03\x1f\x6b\xd7\xe6\x1e\x64\x3d",
+		.iv_out	= "\x03\x1f\x6b\xd7\xe6\x1e\x64\x3d",
 		.generates_iv = true,
 	}, {
 		.key	= "\x80\xaa\x99\x73\x27\xa4\x80\x6b"
@@ -21784,7 +21786,7 @@ static const struct cipher_testvec aes_kw_tv_template[] = {
 		.ctext	= "\xd3\x3d\x3d\x97\x7b\xf0\xa9\x15"
 			  "\x59\xf9\x9c\x8a\xcd\x29\x3d\x43",
 		.len	= 16,
-		.iv	= "\x42\x3c\x96\x0d\x8a\x2a\xc4\xc1",
+		.iv_out	= "\x42\x3c\x96\x0d\x8a\x2a\xc4\xc1",
 		.generates_iv = true,
 	},
 };