diff options
Diffstat (limited to 'arch/arm64/crypto/ghash-ce-glue.c')
-rw-r--r-- | arch/arm64/crypto/ghash-ce-glue.c | 684 |
1 files changed, 684 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 000000000..1ed227bf6 --- /dev/null +++ b/arch/arm64/crypto/ghash-ce-glue.c @@ -0,0 +1,684 @@ +/* + * Accelerated GHASH implementation with ARMv8 PMULL instructions. + * + * Copyright (C) 2014 - 2018 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/simd.h> +#include <asm/unaligned.h> +#include <crypto/aes.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/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 GCM_IV_SIZE 12 + +struct ghash_key { + u64 h[2]; + u64 h2[2]; + u64 h3[2]; + u64 h4[2]; + + be128 k; +}; + +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; + struct ghash_key ghash_key; +}; + +asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src, + struct ghash_key const *k, + const char *head); + +asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src, + struct ghash_key const *k, + const char *head); + +static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src, + struct ghash_key const *k, + const char *head); + +asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[], + const u8 src[], struct ghash_key const *k, + u8 ctr[], u32 const rk[], int rounds, + u8 ks[]); + +asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[], + const u8 src[], struct ghash_key const *k, + u8 ctr[], u32 const rk[], int rounds); + +asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[], + u32 const rk[], int rounds); + +asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); + +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) +{ + if (likely(may_use_simd())) { + kernel_neon_begin(); + pmull_ghash_update(blocks, dg, src, key, head); + kernel_neon_end(); + } else { + 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); + } +} + +/* 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_update(chunk, ctx->digest, src, key, + partial ? ctx->buf : NULL); + + 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_update(1, ctx->digest, ctx->buf, key, NULL); + } + put_unaligned_be64(ctx->digest[1], dst); + put_unaligned_be64(ctx->digest[0], dst + 8); + + *ctx = (struct ghash_desc_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 ghash_key *key, + const u8 *inkey, unsigned int keylen) +{ + be128 h; + + /* needed for the fallback */ + memcpy(&key->k, inkey, GHASH_BLOCK_SIZE); + + ghash_reflect(key->h, &key->k); + + h = key->k; + gf128mul_lle(&h, &key->k); + ghash_reflect(key->h2, &h); + + gf128mul_lle(&h, &key->k); + ghash_reflect(key->h3, &h); + + gf128mul_lle(&h, &key->k); + ghash_reflect(key->h4, &h); + + return 0; +} + +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) { + crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; + } + + return __ghash_setkey(key, inkey, keylen); +} + +static struct shash_alg ghash_alg = { + .base.cra_name = "ghash", + .base.cra_driver_name = "ghash-ce", + .base.cra_priority = 200, + .base.cra_blocksize = GHASH_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct ghash_key), + .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_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]; + int ret; + + ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen); + if (ret) { + tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + __aes_arm64_encrypt(ctx->aes_key.key_enc, key, (u8[AES_BLOCK_SIZE]){}, + num_rounds(&ctx->aes_key)); + + return __ghash_setkey(&ctx->ghash_key, key, sizeof(be128)); +} + +static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + switch (authsize) { + case 4: + case 8: + case 12 ... 16: + break; + default: + return -EINVAL; + } + return 0; +} + +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_update(blocks, dg, src, &ctx->ghash_key, + *buf_count ? buf : NULL); + + 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[]) +{ + 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; + u32 len = req->assoclen; + 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_update(1, dg, buf, &ctx->ghash_key, NULL); + } +} + +static void gcm_final(struct aead_request *req, struct gcm_aes_ctx *ctx, + u64 dg[], u8 tag[], int cryptlen) +{ + u8 mac[AES_BLOCK_SIZE]; + u128 lengths; + + lengths.a = cpu_to_be64(req->assoclen * 8); + lengths.b = cpu_to_be64(cryptlen * 8); + + ghash_do_update(1, dg, (void *)&lengths, &ctx->ghash_key, NULL); + + put_unaligned_be64(dg[1], mac); + put_unaligned_be64(dg[0], mac + 8); + + crypto_xor(tag, mac, AES_BLOCK_SIZE); +} + +static int gcm_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + struct skcipher_walk walk; + u8 iv[AES_BLOCK_SIZE]; + u8 ks[2 * AES_BLOCK_SIZE]; + u8 tag[AES_BLOCK_SIZE]; + u64 dg[2] = {}; + int nrounds = num_rounds(&ctx->aes_key); + int err; + + if (req->assoclen) + gcm_calculate_auth_mac(req, dg); + + memcpy(iv, req->iv, GCM_IV_SIZE); + put_unaligned_be32(1, iv + GCM_IV_SIZE); + + err = skcipher_walk_aead_encrypt(&walk, req, false); + + if (likely(may_use_simd() && walk.total >= 2 * AES_BLOCK_SIZE)) { + u32 const *rk = NULL; + + kernel_neon_begin(); + pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); + put_unaligned_be32(2, iv + GCM_IV_SIZE); + pmull_gcm_encrypt_block(ks, iv, NULL, nrounds); + put_unaligned_be32(3, iv + GCM_IV_SIZE); + pmull_gcm_encrypt_block(ks + AES_BLOCK_SIZE, iv, NULL, nrounds); + put_unaligned_be32(4, iv + GCM_IV_SIZE); + + do { + int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; + + if (rk) + kernel_neon_begin(); + + pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr, + walk.src.virt.addr, &ctx->ghash_key, + iv, rk, nrounds, ks); + kernel_neon_end(); + + err = skcipher_walk_done(&walk, + walk.nbytes % (2 * AES_BLOCK_SIZE)); + + rk = ctx->aes_key.key_enc; + } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); + } else { + __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds); + put_unaligned_be32(2, iv + GCM_IV_SIZE); + + while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { + const int blocks = + walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; + u8 *dst = walk.dst.virt.addr; + u8 *src = walk.src.virt.addr; + int remaining = blocks; + + do { + __aes_arm64_encrypt(ctx->aes_key.key_enc, + ks, iv, nrounds); + crypto_xor_cpy(dst, src, ks, AES_BLOCK_SIZE); + crypto_inc(iv, AES_BLOCK_SIZE); + + dst += AES_BLOCK_SIZE; + src += AES_BLOCK_SIZE; + } while (--remaining > 0); + + ghash_do_update(blocks, dg, + walk.dst.virt.addr, &ctx->ghash_key, + NULL); + + err = skcipher_walk_done(&walk, + walk.nbytes % (2 * AES_BLOCK_SIZE)); + } + if (walk.nbytes) { + __aes_arm64_encrypt(ctx->aes_key.key_enc, ks, iv, + nrounds); + if (walk.nbytes > AES_BLOCK_SIZE) { + crypto_inc(iv, AES_BLOCK_SIZE); + __aes_arm64_encrypt(ctx->aes_key.key_enc, + ks + AES_BLOCK_SIZE, iv, + nrounds); + } + } + } + + /* handle the tail */ + if (walk.nbytes) { + u8 buf[GHASH_BLOCK_SIZE]; + unsigned int nbytes = walk.nbytes; + u8 *dst = walk.dst.virt.addr; + u8 *head = NULL; + + crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, ks, + walk.nbytes); + + if (walk.nbytes > GHASH_BLOCK_SIZE) { + head = dst; + dst += GHASH_BLOCK_SIZE; + nbytes %= GHASH_BLOCK_SIZE; + } + + memcpy(buf, dst, nbytes); + memset(buf + nbytes, 0, GHASH_BLOCK_SIZE - nbytes); + ghash_do_update(!!nbytes, dg, buf, &ctx->ghash_key, head); + + err = skcipher_walk_done(&walk, 0); + } + + if (err) + return err; + + gcm_final(req, ctx, dg, tag, req->cryptlen); + + /* 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) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); + unsigned int authsize = crypto_aead_authsize(aead); + struct skcipher_walk walk; + u8 iv[2 * AES_BLOCK_SIZE]; + u8 tag[AES_BLOCK_SIZE]; + u8 buf[2 * GHASH_BLOCK_SIZE]; + u64 dg[2] = {}; + int nrounds = num_rounds(&ctx->aes_key); + int err; + + if (req->assoclen) + gcm_calculate_auth_mac(req, dg); + + memcpy(iv, req->iv, GCM_IV_SIZE); + put_unaligned_be32(1, iv + GCM_IV_SIZE); + + err = skcipher_walk_aead_decrypt(&walk, req, false); + + if (likely(may_use_simd() && walk.total >= 2 * AES_BLOCK_SIZE)) { + u32 const *rk = NULL; + + kernel_neon_begin(); + pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); + put_unaligned_be32(2, iv + GCM_IV_SIZE); + + do { + int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; + int rem = walk.total - blocks * AES_BLOCK_SIZE; + + if (rk) + kernel_neon_begin(); + + pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr, + walk.src.virt.addr, &ctx->ghash_key, + iv, rk, nrounds); + + /* check if this is the final iteration of the loop */ + if (rem < (2 * AES_BLOCK_SIZE)) { + u8 *iv2 = iv + AES_BLOCK_SIZE; + + if (rem > AES_BLOCK_SIZE) { + memcpy(iv2, iv, AES_BLOCK_SIZE); + crypto_inc(iv2, AES_BLOCK_SIZE); + } + + pmull_gcm_encrypt_block(iv, iv, NULL, nrounds); + + if (rem > AES_BLOCK_SIZE) + pmull_gcm_encrypt_block(iv2, iv2, NULL, + nrounds); + } + + kernel_neon_end(); + + err = skcipher_walk_done(&walk, + walk.nbytes % (2 * AES_BLOCK_SIZE)); + + rk = ctx->aes_key.key_enc; + } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); + } else { + __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds); + put_unaligned_be32(2, iv + GCM_IV_SIZE); + + while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { + int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; + u8 *dst = walk.dst.virt.addr; + u8 *src = walk.src.virt.addr; + + ghash_do_update(blocks, dg, walk.src.virt.addr, + &ctx->ghash_key, NULL); + + do { + __aes_arm64_encrypt(ctx->aes_key.key_enc, + buf, iv, nrounds); + crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE); + crypto_inc(iv, AES_BLOCK_SIZE); + + dst += AES_BLOCK_SIZE; + src += AES_BLOCK_SIZE; + } while (--blocks > 0); + + err = skcipher_walk_done(&walk, + walk.nbytes % (2 * AES_BLOCK_SIZE)); + } + if (walk.nbytes) { + if (walk.nbytes > AES_BLOCK_SIZE) { + u8 *iv2 = iv + AES_BLOCK_SIZE; + + memcpy(iv2, iv, AES_BLOCK_SIZE); + crypto_inc(iv2, AES_BLOCK_SIZE); + + __aes_arm64_encrypt(ctx->aes_key.key_enc, iv2, + iv2, nrounds); + } + __aes_arm64_encrypt(ctx->aes_key.key_enc, iv, iv, + nrounds); + } + } + + /* handle the tail */ + if (walk.nbytes) { + const u8 *src = walk.src.virt.addr; + const u8 *head = NULL; + unsigned int nbytes = walk.nbytes; + + if (walk.nbytes > GHASH_BLOCK_SIZE) { + head = src; + src += GHASH_BLOCK_SIZE; + nbytes %= GHASH_BLOCK_SIZE; + } + + memcpy(buf, src, nbytes); + memset(buf + nbytes, 0, GHASH_BLOCK_SIZE - nbytes); + ghash_do_update(!!nbytes, dg, buf, &ctx->ghash_key, head); + + crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, iv, + walk.nbytes); + + err = skcipher_walk_done(&walk, 0); + } + + if (err) + return err; + + gcm_final(req, ctx, dg, tag, req->cryptlen - authsize); + + /* compare calculated auth tag with the stored one */ + scatterwalk_map_and_copy(buf, req->src, + req->assoclen + req->cryptlen - authsize, + authsize, 0); + + if (crypto_memneq(tag, buf, authsize)) + return -EBADMSG; + return 0; +} + +static struct aead_alg gcm_aes_alg = { + .ivsize = GCM_IV_SIZE, + .chunksize = 2 * AES_BLOCK_SIZE, + .maxauthsize = AES_BLOCK_SIZE, + .setkey = gcm_setkey, + .setauthsize = gcm_setauthsize, + .encrypt = gcm_encrypt, + .decrypt = gcm_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), + .base.cra_module = THIS_MODULE, +}; + +static int __init ghash_ce_mod_init(void) +{ + int ret; + + if (!(elf_hwcap & HWCAP_ASIMD)) + return -ENODEV; + + if (elf_hwcap & HWCAP_PMULL) + pmull_ghash_update = pmull_ghash_update_p64; + + else + pmull_ghash_update = pmull_ghash_update_p8; + + ret = crypto_register_shash(&ghash_alg); + if (ret) + return ret; + + if (elf_hwcap & HWCAP_PMULL) { + ret = crypto_register_aead(&gcm_aes_alg); + if (ret) + crypto_unregister_shash(&ghash_alg); + } + return ret; +} + +static void __exit ghash_ce_mod_exit(void) +{ + crypto_unregister_shash(&ghash_alg); + crypto_unregister_aead(&gcm_aes_alg); +} + +static const struct cpu_feature 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); |