[CRYPTO] ctr: Refactor into ctr and rfc3686

As discussed previously, this patch moves the basic CTR functionality
into a chainable algorithm called ctr.  The IPsec-specific variant of
it is now placed on top with the name rfc3686.

So ctr(aes) gives a chainable cipher with IV size 16 while the IPsec
variant will be called rfc3686(ctr(aes)).  This patch also adjusts
gcm accordingly.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/gcm.c

@@ -160,7 +160,7 @@ static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx,
 
 static inline void crypto_gcm_set_counter(u8 *counterblock, u32 value)
 {
-	*((u32 *)&counterblock[12]) = cpu_to_be32(value);
+	*((u32 *)&counterblock[12]) = cpu_to_be32(value + 1);
 }
 
 static int crypto_gcm_encrypt_counter(struct crypto_aead *aead, u8 *block,
@@ -400,9 +400,8 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
 		return inst;
 
 	inst = ERR_PTR(ENAMETOOLONG);
-	if (snprintf(
-		    ctr_name, CRYPTO_MAX_ALG_NAME,
-		    "ctr(%s,0,16,4)", cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
+	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
+		     cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
 		return inst;
 
 	ctr = crypto_alg_mod_lookup(ctr_name, CRYPTO_ALG_TYPE_BLKCIPHER,

crypto/tcrypt.c

@@ -1193,9 +1193,9 @@ static void do_test(void)
 			    AES_XTS_ENC_TEST_VECTORS);
 		test_cipher("xts(aes)", DECRYPT, aes_xts_dec_tv_template,
 			    AES_XTS_DEC_TEST_VECTORS);
-		test_cipher("ctr(aes,4,8,4)", ENCRYPT, aes_ctr_enc_tv_template,
+		test_cipher("rfc3686(ctr(aes))", ENCRYPT, aes_ctr_enc_tv_template,
 			    AES_CTR_ENC_TEST_VECTORS);
-		test_cipher("ctr(aes,4,8,4)", DECRYPT, aes_ctr_dec_tv_template,
+		test_cipher("rfc3686(ctr(aes))", DECRYPT, aes_ctr_dec_tv_template,
 			    AES_CTR_DEC_TEST_VECTORS);
 		test_aead("gcm(aes)", ENCRYPT, aes_gcm_enc_tv_template,
 			  AES_GCM_ENC_TEST_VECTORS);
@@ -1394,9 +1394,9 @@ static void do_test(void)
 			    AES_XTS_ENC_TEST_VECTORS);
 		test_cipher("xts(aes)", DECRYPT, aes_xts_dec_tv_template,
 			    AES_XTS_DEC_TEST_VECTORS);
-		test_cipher("ctr(aes,4,8,4)", ENCRYPT, aes_ctr_enc_tv_template,
+		test_cipher("rfc3686(ctr(aes))", ENCRYPT, aes_ctr_enc_tv_template,
 			    AES_CTR_ENC_TEST_VECTORS);
-		test_cipher("ctr(aes,4,8,4)", DECRYPT, aes_ctr_dec_tv_template,
+		test_cipher("rfc3686(ctr(aes))", DECRYPT, aes_ctr_dec_tv_template,
 			    AES_CTR_DEC_TEST_VECTORS);
 		break;
 

include/crypto/ctr.h

+/*
+ * CTR: Counter mode
+ *
+ * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _CRYPTO_CTR_H
+#define _CRYPTO_CTR_H
+
+#define CTR_RFC3686_NONCE_SIZE 4
+#define CTR_RFC3686_IV_SIZE 8
+#define CTR_RFC3686_BLOCK_SIZE 16
+
+#endif  /* _CRYPTO_CTR_H */