diff options
Diffstat (limited to 'arch/arm64/crypto/ghash-ce-glue.c')
| -rw-r--r-- | arch/arm64/crypto/ghash-ce-glue.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c new file mode 100644 index 000000000000..833ec1e3f3e9 --- /dev/null +++ b/arch/arm64/crypto/ghash-ce-glue.c @@ -0,0 +1,156 @@ +/* + * Accelerated GHASH implementation with ARMv8 PMULL instructions. + * + * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <asm/neon.h> +#include <asm/unaligned.h> +#include <crypto/internal/hash.h> +#include <linux/cpufeature.h> +#include <linux/crypto.h> +#include <linux/module.h> + +MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions"); +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); + +#define GHASH_BLOCK_SIZE 16 +#define GHASH_DIGEST_SIZE 16 + +struct ghash_key { + u64 a; + u64 b; +}; + +struct ghash_desc_ctx { + u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; + u8 buf[GHASH_BLOCK_SIZE]; + u32 count; +}; + +asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src, + struct ghash_key const *k, const char *head); + +static int ghash_init(struct shash_desc *desc) +{ + struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); + + *ctx = (struct ghash_desc_ctx){}; + return 0; +} + +static int ghash_update(struct shash_desc *desc, const u8 *src, + unsigned int len) +{ + struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); + unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; + + ctx->count += len; + + if ((partial + len) >= GHASH_BLOCK_SIZE) { + struct ghash_key *key = crypto_shash_ctx(desc->tfm); + int blocks; + + if (partial) { + int p = GHASH_BLOCK_SIZE - partial; + + memcpy(ctx->buf + partial, src, p); + src += p; + len -= p; + } + + blocks = len / GHASH_BLOCK_SIZE; + len %= GHASH_BLOCK_SIZE; + + kernel_neon_begin_partial(8); + pmull_ghash_update(blocks, ctx->digest, src, key, + partial ? ctx->buf : NULL); + kernel_neon_end(); + src += blocks * GHASH_BLOCK_SIZE; + partial = 0; + } + if (len) + memcpy(ctx->buf + partial, src, len); + return 0; +} + +static int ghash_final(struct shash_desc *desc, u8 *dst) +{ + struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); + unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; + + if (partial) { + struct ghash_key *key = crypto_shash_ctx(desc->tfm); + + memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); + + kernel_neon_begin_partial(8); + pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL); + kernel_neon_end(); + } + put_unaligned_be64(ctx->digest[1], dst); + put_unaligned_be64(ctx->digest[0], dst + 8); + + *ctx = (struct ghash_desc_ctx){}; + return 0; +} + +static int ghash_setkey(struct crypto_shash *tfm, + const u8 *inkey, unsigned int keylen) +{ + struct ghash_key *key = crypto_shash_ctx(tfm); + u64 a, b; + + if (keylen != GHASH_BLOCK_SIZE) { + crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; + } + + /* perform multiplication by 'x' in GF(2^128) */ + b = get_unaligned_be64(inkey); + a = get_unaligned_be64(inkey + 8); + + key->a = (a << 1) | (b >> 63); + key->b = (b << 1) | (a >> 63); + + if (b >> 63) + key->b ^= 0xc200000000000000UL; + + return 0; +} + +static struct shash_alg ghash_alg = { + .digestsize = GHASH_DIGEST_SIZE, + .init = ghash_init, + .update = ghash_update, + .final = ghash_final, + .setkey = ghash_setkey, + .descsize = sizeof(struct ghash_desc_ctx), + .base = { + .cra_name = "ghash", + .cra_driver_name = "ghash-ce", + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_TYPE_SHASH, + .cra_blocksize = GHASH_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct ghash_key), + .cra_module = THIS_MODULE, + }, +}; + +static int __init ghash_ce_mod_init(void) +{ + return crypto_register_shash(&ghash_alg); +} + +static void __exit ghash_ce_mod_exit(void) +{ + crypto_unregister_shash(&ghash_alg); +} + +module_cpu_feature_match(PMULL, ghash_ce_mod_init); +module_exit(ghash_ce_mod_exit); |