crypto: x86/cast6 - drop CTR mode implementation

CAST6 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/cast6-avx-x86_64-asm_64.S b/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
index 0c1ea83..fbddcec 100644 (file)
--- a/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
+++ b/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
@@ -410,31 +410,3 @@ SYM_FUNC_START(cast6_cbc_dec_8way)
        FRAME_END
        ret;
 SYM_FUNC_END(cast6_cbc_dec_8way)
-
-SYM_FUNC_START(cast6_ctr_8way)
-       /* input:
-        *      %rdi: ctx, CTX
-        *      %rsi: dst
-        *      %rdx: src
-        *      %rcx: iv (little endian, 128bit)
-        */
-       FRAME_BEGIN
-       pushq %r12;
-       pushq %r15
-
-       movq %rdi, CTX;
-       movq %rsi, %r11;
-       movq %rdx, %r12;
-
-       load_ctr_8way(%rcx, .Lbswap128_mask, RA1, RB1, RC1, RD1, RA2, RB2, RC2,
-                     RD2, RX, RKR, RKM);
-
-       call __cast6_enc_blk8;
-
-       store_ctr_8way(%r12, %r11, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);
-
-       popq %r15;
-       popq %r12;
-       FRAME_END
-       ret;
-SYM_FUNC_END(cast6_ctr_8way)

diff --git a/arch/x86/crypto/cast6_avx_glue.c b/arch/x86/crypto/cast6_avx_glue.c
index 5a21d3e..790efcb 100644 (file)
--- a/arch/x86/crypto/cast6_avx_glue.c
+++ b/arch/x86/crypto/cast6_avx_glue.c
@@ -23,8 +23,6 @@ asmlinkage void cast6_ecb_enc_8way(const void *ctx, u8 *dst, const u8 *src);
 asmlinkage void cast6_ecb_dec_8way(const void *ctx, u8 *dst, const u8 *src);
 
 asmlinkage void cast6_cbc_dec_8way(const void *ctx, u8 *dst, const u8 *src);
-asmlinkage void cast6_ctr_8way(const void *ctx, u8 *dst, const u8 *src,
-                              le128 *iv);
 
 static int cast6_setkey_skcipher(struct crypto_skcipher *tfm,
                                 const u8 *key, unsigned int keylen)
@@ -32,19 +30,6 @@ static int cast6_setkey_skcipher(struct crypto_skcipher *tfm,
        return cast6_setkey(&tfm->base, key, keylen);
 }
 
-static void cast6_crypt_ctr(const void *ctx, u8 *d, const u8 *s, le128 *iv)
-{
-       be128 ctrblk;
-       u128 *dst = (u128 *)d;
-       const u128 *src = (const u128 *)s;
-
-       le128_to_be128(&ctrblk, iv);
-       le128_inc(iv);
-
-       __cast6_encrypt(ctx, (u8 *)&ctrblk, (u8 *)&ctrblk);
-       u128_xor(dst, src, (u128 *)&ctrblk);
-}
-
 static const struct common_glue_ctx cast6_enc = {
        .num_funcs = 2,
        .fpu_blocks_limit = CAST6_PARALLEL_BLOCKS,
@@ -58,19 +43,6 @@ static const struct common_glue_ctx cast6_enc = {
        } }
 };
 
-static const struct common_glue_ctx cast6_ctr = {
-       .num_funcs = 2,
-       .fpu_blocks_limit = CAST6_PARALLEL_BLOCKS,
-
-       .funcs = { {
-               .num_blocks = CAST6_PARALLEL_BLOCKS,
-               .fn_u = { .ctr = cast6_ctr_8way }
-       }, {
-               .num_blocks = 1,
-               .fn_u = { .ctr = cast6_crypt_ctr }
-       } }
-};
-
 static const struct common_glue_ctx cast6_dec = {
        .num_funcs = 2,
        .fpu_blocks_limit = CAST6_PARALLEL_BLOCKS,
@@ -117,11 +89,6 @@ static int cbc_decrypt(struct skcipher_request *req)
        return glue_cbc_decrypt_req_128bit(&cast6_dec_cbc, req);
 }
 
-static int ctr_crypt(struct skcipher_request *req)
-{
-       return glue_ctr_req_128bit(&cast6_ctr, req);
-}
-
 static struct skcipher_alg cast6_algs[] = {
        {
                .base.cra_name          = "__ecb(cast6)",
@@ -150,21 +117,6 @@ static struct skcipher_alg cast6_algs[] = {
                .setkey                 = cast6_setkey_skcipher,
                .encrypt                = cbc_encrypt,
                .decrypt                = cbc_decrypt,
-       }, {
-               .base.cra_name          = "__ctr(cast6)",
-               .base.cra_driver_name   = "__ctr-cast6-avx",
-               .base.cra_priority      = 200,
-               .base.cra_flags         = CRYPTO_ALG_INTERNAL,
-               .base.cra_blocksize     = 1,
-               .base.cra_ctxsize       = sizeof(struct cast6_ctx),
-               .base.cra_module        = THIS_MODULE,
-               .min_keysize            = CAST6_MIN_KEY_SIZE,
-               .max_keysize            = CAST6_MAX_KEY_SIZE,
-               .ivsize                 = CAST6_BLOCK_SIZE,
-               .chunksize              = CAST6_BLOCK_SIZE,
-               .setkey                 = cast6_setkey_skcipher,
-               .encrypt                = ctr_crypt,
-               .decrypt                = ctr_crypt,
        },
 };
 

diff --git a/crypto/Kconfig b/crypto/Kconfig
index fed73ff..3f51c5d 100644 (file)
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1397,6 +1397,7 @@ config CRYPTO_CAST6_AVX_X86_64
        select CRYPTO_GLUE_HELPER_X86
        select CRYPTO_SIMD
        imply CRYPTO_XTS
+       imply CRYPTO_CTR
        help
          The CAST6 encryption algorithm (synonymous with CAST-256) is
          described in RFC2612.