[PATCH 17/24] crypto: omap - Forbid 2-key 3DES in FIPS mode

[Herbert Xu <herbert@gondor.apana.org.au>]

This patch forbids the use of 2-key 3DES (K1 == K3) in FIPS mode.

It also removes a couple of unnecessary key length checks that
are already performed by the crypto API.
   
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

 drivers/crypto/omap-des.c |   29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/omap-des.c b/drivers/crypto/omap-des.c
index 1ba2633e90d6..3d82d18ff810 100644
--- a/drivers/crypto/omap-des.c
+++ b/drivers/crypto/omap-des.c
@@ -656,9 +656,6 @@ static int omap_des_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
 	struct omap_des_ctx *ctx = crypto_ablkcipher_ctx(cipher);
 	struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
 
-	if (keylen != DES_KEY_SIZE && keylen != (3*DES_KEY_SIZE))
-		return -EINVAL;
-
 	pr_debug("enter, keylen: %d\n", keylen);
 
 	/* Do we need to test against weak key? */
@@ -678,6 +675,28 @@ static int omap_des_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
 	return 0;
 }
 
+static int omap_des3_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
+			   unsigned int keylen)
+{
+	struct omap_des_ctx *ctx = crypto_ablkcipher_ctx(cipher);
+	u32 flags;
+	int err;
+
+	pr_debug("enter, keylen: %d\n", keylen);
+
+	flags = crypto_ablkcipher_get_flags(cipher);
+	err = __des3_verify_key(&flags, key);
+	if (unlikely(err)) {
+		crypto_ablkcipher_set_flags(cipher, flags);
+		return err;
+	}
+
+	memcpy(ctx->key, key, keylen);
+	ctx->keylen = keylen;
+
+	return 0;
+}
+
 static int omap_des_ecb_encrypt(struct ablkcipher_request *req)
 {
 	return omap_des_crypt(req, FLAGS_ENCRYPT);
@@ -788,7 +807,7 @@ static struct crypto_alg algs_ecb_cbc[] = {
 	.cra_u.ablkcipher = {
 		.min_keysize	= 3*DES_KEY_SIZE,
 		.max_keysize	= 3*DES_KEY_SIZE,
-		.setkey		= omap_des_setkey,
+		.setkey		= omap_des3_setkey,
 		.encrypt	= omap_des_ecb_encrypt,
 		.decrypt	= omap_des_ecb_decrypt,
 	}
@@ -811,7 +830,7 @@ static struct crypto_alg algs_ecb_cbc[] = {
 		.min_keysize	= 3*DES_KEY_SIZE,
 		.max_keysize	= 3*DES_KEY_SIZE,
 		.ivsize		= DES_BLOCK_SIZE,
-		.setkey		= omap_des_setkey,
+		.setkey		= omap_des3_setkey,
 		.encrypt	= omap_des_cbc_encrypt,
 		.decrypt	= omap_des_cbc_decrypt,
 	}