Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Ard Biesheuvel | 3455 | 98.97% | 21 | 77.78% |
Eric Biggers | 12 | 0.34% | 2 | 7.41% |
Andrew Murray | 12 | 0.34% | 1 | 3.70% |
Arvind Sankar | 8 | 0.23% | 1 | 3.70% |
Thomas Gleixner | 2 | 0.06% | 1 | 3.70% |
Herbert Xu | 2 | 0.06% | 1 | 3.70% |
Total | 3491 | 27 |
// 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/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 GCM_IV_SIZE 12 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; 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_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_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_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[]) { 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_simd_update(1, dg, buf, &ctx->ghash_key, NULL, pmull_ghash_update_p64); } } 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); int nrounds = num_rounds(&ctx->aes_key); struct skcipher_walk walk; u8 buf[AES_BLOCK_SIZE]; u8 iv[AES_BLOCK_SIZE]; u64 dg[2] = {}; be128 lengths; u8 *tag; int err; lengths.a = cpu_to_be64(req->assoclen * 8); lengths.b = cpu_to_be64(req->cryptlen * 8); if (req->assoclen) gcm_calculate_auth_mac(req, dg); memcpy(iv, req->iv, GCM_IV_SIZE); put_unaligned_be32(2, iv + GCM_IV_SIZE); err = skcipher_walk_aead_encrypt(&walk, req, false); if (likely(crypto_simd_usable())) { 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); } else { while (walk.nbytes >= AES_BLOCK_SIZE) { int blocks = walk.nbytes / AES_BLOCK_SIZE; const u8 *src = walk.src.virt.addr; u8 *dst = walk.dst.virt.addr; int remaining = blocks; do { aes_encrypt(&ctx->aes_key, buf, iv); crypto_xor_cpy(dst, src, buf, 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 % AES_BLOCK_SIZE); } /* handle the tail */ if (walk.nbytes) { aes_encrypt(&ctx->aes_key, buf, iv); crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, buf, walk.nbytes); memcpy(buf, walk.dst.virt.addr, walk.nbytes); memset(buf + walk.nbytes, 0, sizeof(buf) - walk.nbytes); } tag = (u8 *)&lengths; ghash_do_update(1, dg, tag, &ctx->ghash_key, walk.nbytes ? buf : NULL); if (walk.nbytes) err = skcipher_walk_done(&walk, 0); put_unaligned_be64(dg[1], tag); put_unaligned_be64(dg[0], tag + 8); put_unaligned_be32(1, iv + GCM_IV_SIZE); aes_encrypt(&ctx->aes_key, iv, iv); crypto_xor(tag, iv, AES_BLOCK_SIZE); } 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) { 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]; u8 iv[AES_BLOCK_SIZE]; u64 dg[2] = {}; be128 lengths; u8 *tag; int err; lengths.a = cpu_to_be64(req->assoclen * 8); lengths.b = cpu_to_be64((req->cryptlen - authsize) * 8); if (req->assoclen) gcm_calculate_auth_mac(req, dg); memcpy(iv, req->iv, GCM_IV_SIZE); put_unaligned_be32(2, iv + GCM_IV_SIZE); scatterwalk_map_and_copy(otag, req->src, req->assoclen + req->cryptlen - authsize, authsize, 0); err = skcipher_walk_aead_decrypt(&walk, req, false); if (likely(crypto_simd_usable())) { int ret; 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; if (ret) return -EBADMSG; } else { while (walk.nbytes >= AES_BLOCK_SIZE) { int blocks = walk.nbytes / AES_BLOCK_SIZE; const u8 *src = walk.src.virt.addr; u8 *dst = walk.dst.virt.addr; ghash_do_update(blocks, dg, walk.src.virt.addr, &ctx->ghash_key, NULL); do { aes_encrypt(&ctx->aes_key, buf, iv); 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 % AES_BLOCK_SIZE); } /* handle the tail */ if (walk.nbytes) { memcpy(buf, walk.src.virt.addr, walk.nbytes); memset(buf + walk.nbytes, 0, sizeof(buf) - walk.nbytes); } tag = (u8 *)&lengths; ghash_do_update(1, dg, tag, &ctx->ghash_key, walk.nbytes ? buf : NULL); if (walk.nbytes) { aes_encrypt(&ctx->aes_key, buf, iv); crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, buf, walk.nbytes); err = skcipher_walk_done(&walk, 0); } if (err) return err; put_unaligned_be64(dg[1], tag); put_unaligned_be64(dg[0], tag + 8); put_unaligned_be32(1, iv + GCM_IV_SIZE); aes_encrypt(&ctx->aes_key, iv, iv); crypto_xor(tag, iv, AES_BLOCK_SIZE); if (crypto_memneq(tag, otag, authsize)) { memzero_explicit(tag, AES_BLOCK_SIZE); return -EBADMSG; } } return 0; } static struct aead_alg gcm_aes_alg = { .ivsize = GCM_IV_SIZE, .chunksize = 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) + 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_aead(&gcm_aes_alg); return crypto_register_shash(&ghash_alg); } static void __exit ghash_ce_mod_exit(void) { if (cpu_have_named_feature(PMULL)) crypto_unregister_aead(&gcm_aes_alg); else crypto_unregister_shash(&ghash_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);
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