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 <ebigg...@google.com>
Signed-off-by: Ard Biesheuvel <a...@kernel.org>
---
arch/x86/crypto/cast5_avx_glue.c | 103 --------------------
crypto/Kconfig | 1 +
2 files changed, 1 insertion(+), 103 deletions(-)
diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c
index 384ccb00f9e1..e0d1c7903b29 100644
--- 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 dd48c3bab3f5..fed73fff5a65 100644
--- 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.
--
2.17.1
