crypto: picoxcell - Forbid 2-key 3DES in FIPS mode

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

It also removes an unnecessary key length checks that are already
performed by the crypto API.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/picoxcell_crypto.c b/drivers/crypto/picoxcell_crypto.c
index 1b3acde..975582b 100644 (file)
--- a/drivers/crypto/picoxcell_crypto.c
+++ b/drivers/crypto/picoxcell_crypto.c
@@ -753,11 +753,6 @@ static int spacc_des_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
        struct spacc_ablk_ctx *ctx = crypto_tfm_ctx(tfm);
        u32 tmp[DES_EXPKEY_WORDS];
 
-       if (len > DES3_EDE_KEY_SIZE) {
-               crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN);
-               return -EINVAL;
-       }
-
        if (unlikely(!des_ekey(tmp, key)) &&
            (crypto_ablkcipher_get_flags(cipher) &
             CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) {
@@ -772,6 +767,30 @@ static int spacc_des_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
 }
 
 /*
+ * Set the 3DES key for a block cipher transform. This also performs weak key
+ * checking if the transform has requested it.
+ */
+static int spacc_des3_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
+                            unsigned int len)
+{
+       struct spacc_ablk_ctx *ctx = crypto_ablkcipher_ctx(cipher);
+       u32 flags;
+       int err;
+
+       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, len);
+       ctx->key_len = len;
+
+       return 0;
+}
+
+/*
  * Set the key for an AES block cipher. Some key lengths are not supported in
  * hardware so this must also check whether a fallback is needed.
  */
@@ -1353,7 +1372,7 @@ static struct spacc_alg ipsec_engine_algs[] = {
                        .cra_type = &crypto_ablkcipher_type,
                        .cra_module = THIS_MODULE,
                        .cra_ablkcipher = {
-                               .setkey = spacc_des_setkey,
+                               .setkey = spacc_des3_setkey,
                                .encrypt = spacc_ablk_encrypt,
                                .decrypt = spacc_ablk_decrypt,
                                .min_keysize = DES3_EDE_KEY_SIZE,
@@ -1380,7 +1399,7 @@ static struct spacc_alg ipsec_engine_algs[] = {
                        .cra_type = &crypto_ablkcipher_type,
                        .cra_module = THIS_MODULE,
                        .cra_ablkcipher = {
-                               .setkey = spacc_des_setkey,
+                               .setkey = spacc_des3_setkey,
                                .encrypt = spacc_ablk_encrypt,
                                .decrypt = spacc_ablk_decrypt,
                                .min_keysize = DES3_EDE_KEY_SIZE,