[CRYPTO]: Add setkey operation for digests.

From Jouni Malinen <jkmaline@cc.hut.fi>

Added support for using keyed digest with an optional dit_setkey handler.
This does not change the behavior of the existing digest algorithms, but
allows new ones to add setkey handler that can be used to initialize the
algorithm with a key or seed. setkey is to be called after init, but before
any of the update call(s).

crypto/digest.c

@@ -42,6 +42,15 @@ static void final(struct crypto_tfm *tfm, u8 *out)
 	tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
 }
 
+static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
+{
+	u32 flags;
+	if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
+		return -ENOSYS;
+	return tfm->__crt_alg->cra_digest.dia_setkey(crypto_tfm_ctx(tfm),
+						     key, keylen, &flags);
+}
+
 static void digest(struct crypto_tfm *tfm,
                    struct scatterlist *sg, unsigned int nsg, u8 *out)
 {
@@ -72,6 +81,7 @@ int crypto_init_digest_ops(struct crypto_tfm *tfm)
 	ops->dit_update	= update;
 	ops->dit_final	= final;
 	ops->dit_digest	= digest;
+	ops->dit_setkey	= setkey;
 	
 	return crypto_alloc_hmac_block(tfm);
 }

crypto/tcrypt.c

@@ -112,6 +112,10 @@ test_hash (char * algo, struct hash_testvec * template, unsigned int tcount)
 		sg[0].length = hash_tv[i].psize;
 
 		crypto_digest_init (tfm);
+		if (tfm->crt_u.digest.dit_setkey) {
+			crypto_digest_setkey (tfm, hash_tv[i].key,
+					      hash_tv[i].ksize);
+		}
 		crypto_digest_update (tfm, sg, 1);
 		crypto_digest_final (tfm, result);
 

crypto/tcrypt.h

@@ -30,6 +30,8 @@ struct hash_testvec {
 	char digest[MAX_DIGEST_SIZE];
 	unsigned char np;
 	unsigned char tap[MAX_TAP];		
+	char key[128]; /* only used with keyed hash algorithms */
+	unsigned char ksize;
 };
 
 struct hmac_testvec {	

include/linux/crypto.h

@@ -76,6 +76,8 @@ struct digest_alg {
 	void (*dia_init)(void *ctx);
 	void (*dia_update)(void *ctx, const u8 *data, unsigned int len);
 	void (*dia_final)(void *ctx, u8 *out);
+	int (*dia_setkey)(void *ctx, const u8 *key,
+	                  unsigned int keylen, u32 *flags);
 };
 
 struct compress_alg {
@@ -157,6 +159,8 @@ struct digest_tfm {
 	void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 	void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 	                   unsigned int nsg, u8 *out);
+	int (*dit_setkey)(struct crypto_tfm *tfm,
+	                  const u8 *key, unsigned int keylen);
 #ifdef CONFIG_CRYPTO_HMAC
 	void *dit_hmac_block;
 #endif
@@ -282,6 +286,15 @@ static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 	tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 }
 
+static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
+                                       const u8 *key, unsigned int keylen)
+{
+	BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
+	if (tfm->crt_digest.dit_setkey == NULL)
+		return -ENOSYS;
+	return tfm->crt_digest.dit_setkey(tfm, key, keylen);
+}
+
 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
                                        const u8 *key, unsigned int keylen)
 {