diff options
Diffstat (limited to 'arch/arm64/crypto/ghash-ce-glue.c')
-rw-r--r-- | arch/arm64/crypto/ghash-ce-glue.c | 586 |
1 files changed, 586 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 0000000000..97331b454e --- /dev/null +++ b/arch/arm64/crypto/ghash-ce-glue.c @@ -0,0 +1,586 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Accelerated GHASH implementation with ARMv8 PMULL instructions. + * + * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org> + */ + +#include <asm/neon.h> +#include <asm/simd.h> +#include <asm/unaligned.h> +#include <crypto/aes.h> +#include <crypto/gcm.h> +#include <crypto/algapi.h> +#include <crypto/b128ops.h> +#include <crypto/gf128mul.h> +#include <crypto/internal/aead.h> +#include <crypto/internal/hash.h> +#include <crypto/internal/simd.h> +#include <crypto/internal/skcipher.h> +#include <crypto/scatterwalk.h> +#include <linux/cpufeature.h> +#include <linux/crypto.h> +#include <linux/module.h> + +MODULE_DESCRIPTION("GHASH and AES-GCM using ARMv8 Crypto Extensions"); +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_CRYPTO("ghash"); + +#define GHASH_BLOCK_SIZE 16 +#define GHASH_DIGEST_SIZE 16 + +#define RFC4106_NONCE_SIZE 4 + +struct ghash_key { + be128 k; + u64 h[][2]; +}; + +struct ghash_desc_ctx { + u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; + u8 buf[GHASH_BLOCK_SIZE]; + u32 count; +}; + +struct gcm_aes_ctx { + struct crypto_aes_ctx aes_key; + u8 nonce[RFC4106_NONCE_SIZE]; + struct ghash_key ghash_key; +}; + +asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src, + u64 const h[][2], const char *head); + +asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src, + u64 const h[][2], const char *head); + +asmlinkage void pmull_gcm_encrypt(int bytes, u8 dst[], const u8 src[], + u64 const h[][2], u64 dg[], u8 ctr[], + u32 const rk[], int rounds, u8 tag[]); +asmlinkage int pmull_gcm_decrypt(int bytes, u8 dst[], const u8 src[], + u64 const h[][2], u64 dg[], u8 ctr[], + u32 const rk[], int rounds, const u8 l[], + const u8 tag[], u64 authsize); + +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 void ghash_do_update(int blocks, u64 dg[], const char *src, + struct ghash_key *key, const char *head) +{ + be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) }; + + do { + const u8 *in = src; + + if (head) { + in = head; + blocks++; + head = NULL; + } else { + src += GHASH_BLOCK_SIZE; + } + + crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE); + gf128mul_lle(&dst, &key->k); + } while (--blocks); + + dg[0] = be64_to_cpu(dst.b); + dg[1] = be64_to_cpu(dst.a); +} + +static __always_inline +void ghash_do_simd_update(int blocks, u64 dg[], const char *src, + struct ghash_key *key, const char *head, + void (*simd_update)(int blocks, u64 dg[], + const char *src, + u64 const h[][2], + const char *head)) +{ + if (likely(crypto_simd_usable())) { + kernel_neon_begin(); + simd_update(blocks, dg, src, key->h, head); + kernel_neon_end(); + } else { + ghash_do_update(blocks, dg, src, key, head); + } +} + +/* avoid hogging the CPU for too long */ +#define MAX_BLOCKS (SZ_64K / GHASH_BLOCK_SIZE) + +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; + + do { + int chunk = min(blocks, MAX_BLOCKS); + + ghash_do_simd_update(chunk, ctx->digest, src, key, + partial ? ctx->buf : NULL, + pmull_ghash_update_p8); + + blocks -= chunk; + src += chunk * GHASH_BLOCK_SIZE; + partial = 0; + } while (unlikely(blocks > 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); + + ghash_do_simd_update(1, ctx->digest, ctx->buf, key, NULL, + pmull_ghash_update_p8); + } + put_unaligned_be64(ctx->digest[1], dst); + put_unaligned_be64(ctx->digest[0], dst + 8); + + memzero_explicit(ctx, sizeof(*ctx)); + return 0; +} + +static void ghash_reflect(u64 h[], const be128 *k) +{ + u64 carry = be64_to_cpu(k->a) & BIT(63) ? 1 : 0; + + h[0] = (be64_to_cpu(k->b) << 1) | carry; + h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63); + + if (carry) + h[1] ^= 0xc200000000000000UL; +} + +static int ghash_setkey(struct crypto_shash *tfm, + const u8 *inkey, unsigned int keylen) +{ + struct ghash_key *key = crypto_shash_ctx(tfm); + + if (keylen != GHASH_BLOCK_SIZE) + return -EINVAL; + + /* needed for the fallback */ + memcpy(&key->k, inkey, GHASH_BLOCK_SIZE); + + ghash_reflect(key->h[0], &key->k); + return 0; +} + +static struct shash_alg ghash_alg = { + .base.cra_name = "ghash", + .base.cra_driver_name = "ghash-neon", + .base.cra_priority = 150, + .base.cra_blocksize = GHASH_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct ghash_key) + sizeof(u64[2]), + .base.cra_module = THIS_MODULE, + + .digestsize = GHASH_DIGEST_SIZE, + .init = ghash_init, + .update = ghash_update, + .final = ghash_final, + .setkey = ghash_setkey, + .descsize = sizeof(struct ghash_desc_ctx), +}; + +static int num_rounds(struct crypto_aes_ctx *ctx) +{ + /* + * # of rounds specified by AES: + * 128 bit key 10 rounds + * 192 bit key 12 rounds + * 256 bit key 14 rounds + * => n byte key => 6 + (n/4) rounds + */ + return 6 + ctx->key_length / 4; +} + +static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *inkey, + unsigned int keylen) +{ + struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm); + u8 key[GHASH_BLOCK_SIZE]; + be128 h; + int ret; + + ret = aes_expandkey(&ctx->aes_key, inkey, keylen); + if (ret) + return -EINVAL; + + aes_encrypt(&ctx->aes_key, key, (u8[AES_BLOCK_SIZE]){}); + + /* needed for the fallback */ + memcpy(&ctx->ghash_key.k, key, GHASH_BLOCK_SIZE); + + ghash_reflect(ctx->ghash_key.h[0], &ctx->ghash_key.k); + + h = ctx->ghash_key.k; + gf128mul_lle(&h, &ctx->ghash_key.k); + ghash_reflect(ctx->ghash_key.h[1], &h); + + gf128mul_lle(&h, &ctx->ghash_key.k); + ghash_reflect(ctx->ghash_key.h[2], &h); + + gf128mul_lle(&h, &ctx->ghash_key.k); + ghash_reflect(ctx->ghash_key.h[3], &h); + + return 0; +} + +static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + return crypto_gcm_check_authsize(authsize); +} + +static void gcm_update_mac(u64 dg[], const u8 *src, int count, u8 buf[], + int *buf_count, struct gcm_aes_ctx *ctx) +{ + if (*buf_count > 0) { + int buf_added = min(count, GHASH_BLOCK_SIZE - *buf_count); + + memcpy(&buf[*buf_count], src, buf_added); + + *buf_count += buf_added; + src += buf_added; + count -= buf_added; + } + + if (count >= GHASH_BLOCK_SIZE || *buf_count == GHASH_BLOCK_SIZE) { + int blocks = count / GHASH_BLOCK_SIZE; + + ghash_do_simd_update(blocks, dg, src, &ctx->ghash_key, + *buf_count ? buf : NULL, + pmull_ghash_update_p64); + + src += blocks * GHASH_BLOCK_SIZE; + count %= GHASH_BLOCK_SIZE; + *buf_count = 0; + } + + if (count > 0) { + memcpy(buf, src, count); + *buf_count = count; + } +} + +static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[], u32 len) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + u8 buf[GHASH_BLOCK_SIZE]; + struct scatter_walk walk; + int buf_count = 0; + + scatterwalk_start(&walk, req->src); + + do { + u32 n = scatterwalk_clamp(&walk, len); + u8 *p; + + if (!n) { + scatterwalk_start(&walk, sg_next(walk.sg)); + n = scatterwalk_clamp(&walk, len); + } + p = scatterwalk_map(&walk); + + gcm_update_mac(dg, p, n, buf, &buf_count, ctx); + len -= n; + + scatterwalk_unmap(p); + scatterwalk_advance(&walk, n); + scatterwalk_done(&walk, 0, len); + } while (len); + + if (buf_count) { + memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count); + ghash_do_simd_update(1, dg, buf, &ctx->ghash_key, NULL, + pmull_ghash_update_p64); + } +} + +static int gcm_encrypt(struct aead_request *req, char *iv, int assoclen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + int nrounds = num_rounds(&ctx->aes_key); + struct skcipher_walk walk; + u8 buf[AES_BLOCK_SIZE]; + u64 dg[2] = {}; + be128 lengths; + u8 *tag; + int err; + + lengths.a = cpu_to_be64(assoclen * 8); + lengths.b = cpu_to_be64(req->cryptlen * 8); + + if (assoclen) + gcm_calculate_auth_mac(req, dg, assoclen); + + put_unaligned_be32(2, iv + GCM_AES_IV_SIZE); + + err = skcipher_walk_aead_encrypt(&walk, req, false); + + do { + const u8 *src = walk.src.virt.addr; + u8 *dst = walk.dst.virt.addr; + int nbytes = walk.nbytes; + + tag = (u8 *)&lengths; + + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) { + src = dst = memcpy(buf + sizeof(buf) - nbytes, + src, nbytes); + } else if (nbytes < walk.total) { + nbytes &= ~(AES_BLOCK_SIZE - 1); + tag = NULL; + } + + kernel_neon_begin(); + pmull_gcm_encrypt(nbytes, dst, src, ctx->ghash_key.h, + dg, iv, ctx->aes_key.key_enc, nrounds, + tag); + kernel_neon_end(); + + if (unlikely(!nbytes)) + break; + + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) + memcpy(walk.dst.virt.addr, + buf + sizeof(buf) - nbytes, nbytes); + + err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + } while (walk.nbytes); + + if (err) + return err; + + /* copy authtag to end of dst */ + scatterwalk_map_and_copy(tag, req->dst, req->assoclen + req->cryptlen, + crypto_aead_authsize(aead), 1); + + return 0; +} + +static int gcm_decrypt(struct aead_request *req, char *iv, int assoclen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + unsigned int authsize = crypto_aead_authsize(aead); + int nrounds = num_rounds(&ctx->aes_key); + struct skcipher_walk walk; + u8 otag[AES_BLOCK_SIZE]; + u8 buf[AES_BLOCK_SIZE]; + u64 dg[2] = {}; + be128 lengths; + u8 *tag; + int ret; + int err; + + lengths.a = cpu_to_be64(assoclen * 8); + lengths.b = cpu_to_be64((req->cryptlen - authsize) * 8); + + if (assoclen) + gcm_calculate_auth_mac(req, dg, assoclen); + + put_unaligned_be32(2, iv + GCM_AES_IV_SIZE); + + scatterwalk_map_and_copy(otag, req->src, + req->assoclen + req->cryptlen - authsize, + authsize, 0); + + err = skcipher_walk_aead_decrypt(&walk, req, false); + + do { + const u8 *src = walk.src.virt.addr; + u8 *dst = walk.dst.virt.addr; + int nbytes = walk.nbytes; + + tag = (u8 *)&lengths; + + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) { + src = dst = memcpy(buf + sizeof(buf) - nbytes, + src, nbytes); + } else if (nbytes < walk.total) { + nbytes &= ~(AES_BLOCK_SIZE - 1); + tag = NULL; + } + + kernel_neon_begin(); + ret = pmull_gcm_decrypt(nbytes, dst, src, ctx->ghash_key.h, + dg, iv, ctx->aes_key.key_enc, + nrounds, tag, otag, authsize); + kernel_neon_end(); + + if (unlikely(!nbytes)) + break; + + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) + memcpy(walk.dst.virt.addr, + buf + sizeof(buf) - nbytes, nbytes); + + err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + } while (walk.nbytes); + + if (err) + return err; + + return ret ? -EBADMSG : 0; +} + +static int gcm_aes_encrypt(struct aead_request *req) +{ + u8 iv[AES_BLOCK_SIZE]; + + memcpy(iv, req->iv, GCM_AES_IV_SIZE); + return gcm_encrypt(req, iv, req->assoclen); +} + +static int gcm_aes_decrypt(struct aead_request *req) +{ + u8 iv[AES_BLOCK_SIZE]; + + memcpy(iv, req->iv, GCM_AES_IV_SIZE); + return gcm_decrypt(req, iv, req->assoclen); +} + +static int rfc4106_setkey(struct crypto_aead *tfm, const u8 *inkey, + unsigned int keylen) +{ + struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm); + int err; + + keylen -= RFC4106_NONCE_SIZE; + err = gcm_aes_setkey(tfm, inkey, keylen); + if (err) + return err; + + memcpy(ctx->nonce, inkey + keylen, RFC4106_NONCE_SIZE); + return 0; +} + +static int rfc4106_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + return crypto_rfc4106_check_authsize(authsize); +} + +static int rfc4106_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + u8 iv[AES_BLOCK_SIZE]; + + memcpy(iv, ctx->nonce, RFC4106_NONCE_SIZE); + memcpy(iv + RFC4106_NONCE_SIZE, req->iv, GCM_RFC4106_IV_SIZE); + + return crypto_ipsec_check_assoclen(req->assoclen) ?: + gcm_encrypt(req, iv, req->assoclen - GCM_RFC4106_IV_SIZE); +} + +static int rfc4106_decrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + u8 iv[AES_BLOCK_SIZE]; + + memcpy(iv, ctx->nonce, RFC4106_NONCE_SIZE); + memcpy(iv + RFC4106_NONCE_SIZE, req->iv, GCM_RFC4106_IV_SIZE); + + return crypto_ipsec_check_assoclen(req->assoclen) ?: + gcm_decrypt(req, iv, req->assoclen - GCM_RFC4106_IV_SIZE); +} + +static struct aead_alg gcm_aes_algs[] = {{ + .ivsize = GCM_AES_IV_SIZE, + .chunksize = AES_BLOCK_SIZE, + .maxauthsize = AES_BLOCK_SIZE, + .setkey = gcm_aes_setkey, + .setauthsize = gcm_aes_setauthsize, + .encrypt = gcm_aes_encrypt, + .decrypt = gcm_aes_decrypt, + + .base.cra_name = "gcm(aes)", + .base.cra_driver_name = "gcm-aes-ce", + .base.cra_priority = 300, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct gcm_aes_ctx) + + 4 * sizeof(u64[2]), + .base.cra_module = THIS_MODULE, +}, { + .ivsize = GCM_RFC4106_IV_SIZE, + .chunksize = AES_BLOCK_SIZE, + .maxauthsize = AES_BLOCK_SIZE, + .setkey = rfc4106_setkey, + .setauthsize = rfc4106_setauthsize, + .encrypt = rfc4106_encrypt, + .decrypt = rfc4106_decrypt, + + .base.cra_name = "rfc4106(gcm(aes))", + .base.cra_driver_name = "rfc4106-gcm-aes-ce", + .base.cra_priority = 300, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct gcm_aes_ctx) + + 4 * sizeof(u64[2]), + .base.cra_module = THIS_MODULE, +}}; + +static int __init ghash_ce_mod_init(void) +{ + if (!cpu_have_named_feature(ASIMD)) + return -ENODEV; + + if (cpu_have_named_feature(PMULL)) + return crypto_register_aeads(gcm_aes_algs, + ARRAY_SIZE(gcm_aes_algs)); + + return crypto_register_shash(&ghash_alg); +} + +static void __exit ghash_ce_mod_exit(void) +{ + if (cpu_have_named_feature(PMULL)) + crypto_unregister_aeads(gcm_aes_algs, ARRAY_SIZE(gcm_aes_algs)); + else + crypto_unregister_shash(&ghash_alg); +} + +static const struct cpu_feature __maybe_unused ghash_cpu_feature[] = { + { cpu_feature(PMULL) }, { } +}; +MODULE_DEVICE_TABLE(cpu, ghash_cpu_feature); + +module_init(ghash_ce_mod_init); +module_exit(ghash_ce_mod_exit); |