crypto: arm64/chacha - remove the skcipher algorithms
authorEric Biggers <ebiggers@google.com>
Sat, 5 Apr 2025 18:26:04 +0000 (11:26 -0700)
committerHerbert Xu <herbert@gondor.apana.org.au>
Mon, 7 Apr 2025 05:22:28 +0000 (13:22 +0800)
Since crypto/chacha.c now registers chacha20-$(ARCH), xchacha20-$(ARCH),
and xchacha12-$(ARCH) skcipher algorithms that use the architecture's
ChaCha and HChaCha library functions, individual architectures no longer
need to do the same.  Therefore, remove the redundant skcipher
algorithms and leave just the library functions.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
arch/arm64/crypto/Kconfig
arch/arm64/crypto/chacha-neon-core.S
arch/arm64/crypto/chacha-neon-glue.c

index 3418c8d..ce655da 100644 (file)
@@ -189,16 +189,9 @@ config CRYPTO_AES_ARM64_NEON_BLK
 config CRYPTO_CHACHA20_NEON
        tristate
        depends on KERNEL_MODE_NEON
-       select CRYPTO_SKCIPHER
        select CRYPTO_LIB_CHACHA_GENERIC
        select CRYPTO_ARCH_HAVE_LIB_CHACHA
        default CRYPTO_LIB_CHACHA_INTERNAL
-       help
-         Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12
-         stream cipher algorithms
-
-         Architecture: arm64 using:
-         - NEON (Advanced SIMD) extensions
 
 config CRYPTO_AES_ARM64_BS
        tristate "Ciphers: AES, modes: ECB/CBC/CTR/XCTR/XTS modes (bit-sliced NEON)"
index b70ac76..8007958 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * ChaCha/XChaCha NEON helper functions
+ * ChaCha/HChaCha NEON helper functions
  *
  * Copyright (C) 2016-2018 Linaro, Ltd. <ard.biesheuvel@linaro.org>
  *
index bb9b523..a0c336b 100644 (file)
@@ -1,6 +1,5 @@
 /*
- * ARM NEON and scalar accelerated ChaCha and XChaCha stream ciphers,
- * including ChaCha20 (RFC7539)
+ * ChaCha and HChaCha functions (ARM64 optimized)
  *
  * Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
  *
  * (at your option) any later version.
  */
 
-#include <crypto/algapi.h>
-#include <crypto/internal/chacha.h>
+#include <crypto/chacha.h>
 #include <crypto/internal/simd.h>
-#include <crypto/internal/skcipher.h>
 #include <linux/jump_label.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -95,117 +92,6 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
 }
 EXPORT_SYMBOL(chacha_crypt_arch);
 
-static int chacha_neon_stream_xor(struct skcipher_request *req,
-                                 const struct chacha_ctx *ctx, const u8 *iv)
-{
-       struct skcipher_walk walk;
-       u32 state[16];
-       int err;
-
-       err = skcipher_walk_virt(&walk, req, false);
-
-       chacha_init(state, ctx->key, iv);
-
-       while (walk.nbytes > 0) {
-               unsigned int nbytes = walk.nbytes;
-
-               if (nbytes < walk.total)
-                       nbytes = rounddown(nbytes, walk.stride);
-
-               if (!static_branch_likely(&have_neon) ||
-                   !crypto_simd_usable()) {
-                       chacha_crypt_generic(state, walk.dst.virt.addr,
-                                            walk.src.virt.addr, nbytes,
-                                            ctx->nrounds);
-               } else {
-                       kernel_neon_begin();
-                       chacha_doneon(state, walk.dst.virt.addr,
-                                     walk.src.virt.addr, nbytes, ctx->nrounds);
-                       kernel_neon_end();
-               }
-               err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
-       }
-
-       return err;
-}
-
-static int chacha_neon(struct skcipher_request *req)
-{
-       struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-       struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
-
-       return chacha_neon_stream_xor(req, ctx, req->iv);
-}
-
-static int xchacha_neon(struct skcipher_request *req)
-{
-       struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-       struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
-       struct chacha_ctx subctx;
-       u32 state[16];
-       u8 real_iv[16];
-
-       chacha_init(state, ctx->key, req->iv);
-       hchacha_block_arch(state, subctx.key, ctx->nrounds);
-       subctx.nrounds = ctx->nrounds;
-
-       memcpy(&real_iv[0], req->iv + 24, 8);
-       memcpy(&real_iv[8], req->iv + 16, 8);
-       return chacha_neon_stream_xor(req, &subctx, real_iv);
-}
-
-static struct skcipher_alg algs[] = {
-       {
-               .base.cra_name          = "chacha20",
-               .base.cra_driver_name   = "chacha20-neon",
-               .base.cra_priority      = 300,
-               .base.cra_blocksize     = 1,
-               .base.cra_ctxsize       = sizeof(struct chacha_ctx),
-               .base.cra_module        = THIS_MODULE,
-
-               .min_keysize            = CHACHA_KEY_SIZE,
-               .max_keysize            = CHACHA_KEY_SIZE,
-               .ivsize                 = CHACHA_IV_SIZE,
-               .chunksize              = CHACHA_BLOCK_SIZE,
-               .walksize               = 5 * CHACHA_BLOCK_SIZE,
-               .setkey                 = chacha20_setkey,
-               .encrypt                = chacha_neon,
-               .decrypt                = chacha_neon,
-       }, {
-               .base.cra_name          = "xchacha20",
-               .base.cra_driver_name   = "xchacha20-neon",
-               .base.cra_priority      = 300,
-               .base.cra_blocksize     = 1,
-               .base.cra_ctxsize       = sizeof(struct chacha_ctx),
-               .base.cra_module        = THIS_MODULE,
-
-               .min_keysize            = CHACHA_KEY_SIZE,
-               .max_keysize            = CHACHA_KEY_SIZE,
-               .ivsize                 = XCHACHA_IV_SIZE,
-               .chunksize              = CHACHA_BLOCK_SIZE,
-               .walksize               = 5 * CHACHA_BLOCK_SIZE,
-               .setkey                 = chacha20_setkey,
-               .encrypt                = xchacha_neon,
-               .decrypt                = xchacha_neon,
-       }, {
-               .base.cra_name          = "xchacha12",
-               .base.cra_driver_name   = "xchacha12-neon",
-               .base.cra_priority      = 300,
-               .base.cra_blocksize     = 1,
-               .base.cra_ctxsize       = sizeof(struct chacha_ctx),
-               .base.cra_module        = THIS_MODULE,
-
-               .min_keysize            = CHACHA_KEY_SIZE,
-               .max_keysize            = CHACHA_KEY_SIZE,
-               .ivsize                 = XCHACHA_IV_SIZE,
-               .chunksize              = CHACHA_BLOCK_SIZE,
-               .walksize               = 5 * CHACHA_BLOCK_SIZE,
-               .setkey                 = chacha12_setkey,
-               .encrypt                = xchacha_neon,
-               .decrypt                = xchacha_neon,
-       }
-};
-
 bool chacha_is_arch_optimized(void)
 {
        return static_key_enabled(&have_neon);
@@ -214,30 +100,12 @@ EXPORT_SYMBOL(chacha_is_arch_optimized);
 
 static int __init chacha_simd_mod_init(void)
 {
-       if (!cpu_have_named_feature(ASIMD))
-               return 0;
-
-       static_branch_enable(&have_neon);
-
-       return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
-               crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
+       if (cpu_have_named_feature(ASIMD))
+               static_branch_enable(&have_neon);
+       return 0;
 }
-
-static void __exit chacha_simd_mod_fini(void)
-{
-       if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && cpu_have_named_feature(ASIMD))
-               crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
-}
-
 arch_initcall(chacha_simd_mod_init);
-module_exit(chacha_simd_mod_fini);
 
-MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (NEON accelerated)");
+MODULE_DESCRIPTION("ChaCha and HChaCha functions (ARM64 optimized)");
 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_LICENSE("GPL v2");
-MODULE_ALIAS_CRYPTO("chacha20");
-MODULE_ALIAS_CRYPTO("chacha20-neon");
-MODULE_ALIAS_CRYPTO("xchacha20");
-MODULE_ALIAS_CRYPTO("xchacha20-neon");
-MODULE_ALIAS_CRYPTO("xchacha12");
-MODULE_ALIAS_CRYPTO("xchacha12-neon");