crypto: x86/cast5 - drop CTR mode implementation

CAST5 in CTR mode is never used by the kernel directly, and is highly
unlikely to be relied upon by dm-crypt or algif_skcipher. So let's drop
the accelerated CTR mode implementation, and instead, rely on the CTR
template and the bare cipher.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c
index 384ccb0..e0d1c79 100644 (file)
--- a/arch/x86/crypto/cast5_avx_glue.c
+++ b/arch/x86/crypto/cast5_avx_glue.c
@@ -23,8 +23,6 @@ asmlinkage void cast5_ecb_dec_16way(struct cast5_ctx *ctx, u8 *dst,
                                    const u8 *src);
 asmlinkage void cast5_cbc_dec_16way(struct cast5_ctx *ctx, u8 *dst,
                                    const u8 *src);
-asmlinkage void cast5_ctr_16way(struct cast5_ctx *ctx, u8 *dst, const u8 *src,
-                               __be64 *iv);
 
 static int cast5_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
                                 unsigned int keylen)
@@ -214,92 +212,6 @@ static int cbc_decrypt(struct skcipher_request *req)
        return err;
 }
 
-static void ctr_crypt_final(struct skcipher_walk *walk, struct cast5_ctx *ctx)
-{
-       u8 *ctrblk = walk->iv;
-       u8 keystream[CAST5_BLOCK_SIZE];
-       u8 *src = walk->src.virt.addr;
-       u8 *dst = walk->dst.virt.addr;
-       unsigned int nbytes = walk->nbytes;
-
-       __cast5_encrypt(ctx, keystream, ctrblk);
-       crypto_xor_cpy(dst, keystream, src, nbytes);
-
-       crypto_inc(ctrblk, CAST5_BLOCK_SIZE);
-}
-
-static unsigned int __ctr_crypt(struct skcipher_walk *walk,
-                               struct cast5_ctx *ctx)
-{
-       const unsigned int bsize = CAST5_BLOCK_SIZE;
-       unsigned int nbytes = walk->nbytes;
-       u64 *src = (u64 *)walk->src.virt.addr;
-       u64 *dst = (u64 *)walk->dst.virt.addr;
-
-       /* Process multi-block batch */
-       if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
-               do {
-                       cast5_ctr_16way(ctx, (u8 *)dst, (u8 *)src,
-                                       (__be64 *)walk->iv);
-
-                       src += CAST5_PARALLEL_BLOCKS;
-                       dst += CAST5_PARALLEL_BLOCKS;
-                       nbytes -= bsize * CAST5_PARALLEL_BLOCKS;
-               } while (nbytes >= bsize * CAST5_PARALLEL_BLOCKS);
-
-               if (nbytes < bsize)
-                       goto done;
-       }
-
-       /* Handle leftovers */
-       do {
-               u64 ctrblk;
-
-               if (dst != src)
-                       *dst = *src;
-
-               ctrblk = *(u64 *)walk->iv;
-               be64_add_cpu((__be64 *)walk->iv, 1);
-
-               __cast5_encrypt(ctx, (u8 *)&ctrblk, (u8 *)&ctrblk);
-               *dst ^= ctrblk;
-
-               src += 1;
-               dst += 1;
-               nbytes -= bsize;
-       } while (nbytes >= bsize);
-
-done:
-       return nbytes;
-}
-
-static int ctr_crypt(struct skcipher_request *req)
-{
-       struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-       struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
-       bool fpu_enabled = false;
-       struct skcipher_walk walk;
-       unsigned int nbytes;
-       int err;
-
-       err = skcipher_walk_virt(&walk, req, false);
-
-       while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) {
-               fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
-               nbytes = __ctr_crypt(&walk, ctx);
-               err = skcipher_walk_done(&walk, nbytes);
-       }
-
-       cast5_fpu_end(fpu_enabled);
-
-       if (walk.nbytes) {
-               ctr_crypt_final(&walk, ctx);
-               err = skcipher_walk_done(&walk, 0);
-       }
-
-       return err;
-}
-
 static struct skcipher_alg cast5_algs[] = {
        {
                .base.cra_name          = "__ecb(cast5)",
@@ -328,21 +240,6 @@ static struct skcipher_alg cast5_algs[] = {
                .setkey                 = cast5_setkey_skcipher,
                .encrypt                = cbc_encrypt,
                .decrypt                = cbc_decrypt,
-       }, {
-               .base.cra_name          = "__ctr(cast5)",
-               .base.cra_driver_name   = "__ctr-cast5-avx",
-               .base.cra_priority      = 200,
-               .base.cra_flags         = CRYPTO_ALG_INTERNAL,
-               .base.cra_blocksize     = 1,
-               .base.cra_ctxsize       = sizeof(struct cast5_ctx),
-               .base.cra_module        = THIS_MODULE,
-               .min_keysize            = CAST5_MIN_KEY_SIZE,
-               .max_keysize            = CAST5_MAX_KEY_SIZE,
-               .ivsize                 = CAST5_BLOCK_SIZE,
-               .chunksize              = CAST5_BLOCK_SIZE,
-               .setkey                 = cast5_setkey_skcipher,
-               .encrypt                = ctr_crypt,
-               .decrypt                = ctr_crypt,
        }
 };
 

diff --git a/crypto/Kconfig b/crypto/Kconfig
index dd48c3b..fed73ff 100644 (file)
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1372,6 +1372,7 @@ config CRYPTO_CAST5_AVX_X86_64
        select CRYPTO_CAST5
        select CRYPTO_CAST_COMMON
        select CRYPTO_SIMD
+       imply CRYPTO_CTR
        help
          The CAST5 encryption algorithm (synonymous with CAST-128) is
          described in RFC2144.