diff options
Diffstat (limited to 'arch/arm/crypto/aes-ce-glue.c')
-rw-r--r-- | arch/arm/crypto/aes-ce-glue.c | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/arch/arm/crypto/aes-ce-glue.c b/arch/arm/crypto/aes-ce-glue.c new file mode 100644 index 000000000..d0a9cec73 --- /dev/null +++ b/arch/arm/crypto/aes-ce-glue.c @@ -0,0 +1,451 @@ +/* + * aes-ce-glue.c - wrapper code for ARMv8 AES + * + * Copyright (C) 2015 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/hwcap.h> +#include <asm/neon.h> +#include <asm/hwcap.h> +#include <crypto/aes.h> +#include <crypto/internal/simd.h> +#include <crypto/internal/skcipher.h> +#include <linux/cpufeature.h> +#include <linux/module.h> +#include <crypto/xts.h> + +MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions"); +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); + +/* defined in aes-ce-core.S */ +asmlinkage u32 ce_aes_sub(u32 input); +asmlinkage void ce_aes_invert(void *dst, void *src); + +asmlinkage void ce_aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[], + int rounds, int blocks); +asmlinkage void ce_aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[], + int rounds, int blocks); + +asmlinkage void ce_aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[], + int rounds, int blocks, u8 iv[]); +asmlinkage void ce_aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], + int rounds, int blocks, u8 iv[]); + +asmlinkage void ce_aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], + int rounds, int blocks, u8 ctr[]); + +asmlinkage void ce_aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[], + int rounds, int blocks, u8 iv[], + u8 const rk2[], int first); +asmlinkage void ce_aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[], + int rounds, int blocks, u8 iv[], + u8 const rk2[], int first); + +struct aes_block { + u8 b[AES_BLOCK_SIZE]; +}; + +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 ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, + unsigned int key_len) +{ + /* + * The AES key schedule round constants + */ + static u8 const rcon[] = { + 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, + }; + + u32 kwords = key_len / sizeof(u32); + struct aes_block *key_enc, *key_dec; + int i, j; + + if (key_len != AES_KEYSIZE_128 && + key_len != AES_KEYSIZE_192 && + key_len != AES_KEYSIZE_256) + return -EINVAL; + + memcpy(ctx->key_enc, in_key, key_len); + ctx->key_length = key_len; + + kernel_neon_begin(); + for (i = 0; i < sizeof(rcon); i++) { + u32 *rki = ctx->key_enc + (i * kwords); + u32 *rko = rki + kwords; + +#ifndef CONFIG_CPU_BIG_ENDIAN + rko[0] = ror32(ce_aes_sub(rki[kwords - 1]), 8); + rko[0] = rko[0] ^ rki[0] ^ rcon[i]; +#else + rko[0] = rol32(ce_aes_sub(rki[kwords - 1]), 8); + rko[0] = rko[0] ^ rki[0] ^ (rcon[i] << 24); +#endif + rko[1] = rko[0] ^ rki[1]; + rko[2] = rko[1] ^ rki[2]; + rko[3] = rko[2] ^ rki[3]; + + if (key_len == AES_KEYSIZE_192) { + if (i >= 7) + break; + rko[4] = rko[3] ^ rki[4]; + rko[5] = rko[4] ^ rki[5]; + } else if (key_len == AES_KEYSIZE_256) { + if (i >= 6) + break; + rko[4] = ce_aes_sub(rko[3]) ^ rki[4]; + rko[5] = rko[4] ^ rki[5]; + rko[6] = rko[5] ^ rki[6]; + rko[7] = rko[6] ^ rki[7]; + } + } + + /* + * Generate the decryption keys for the Equivalent Inverse Cipher. + * This involves reversing the order of the round keys, and applying + * the Inverse Mix Columns transformation on all but the first and + * the last one. + */ + key_enc = (struct aes_block *)ctx->key_enc; + key_dec = (struct aes_block *)ctx->key_dec; + j = num_rounds(ctx); + + key_dec[0] = key_enc[j]; + for (i = 1, j--; j > 0; i++, j--) + ce_aes_invert(key_dec + i, key_enc + j); + key_dec[i] = key_enc[0]; + + kernel_neon_end(); + return 0; +} + +static int ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + int ret; + + ret = ce_aes_expandkey(ctx, in_key, key_len); + if (!ret) + return 0; + + crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; +} + +struct crypto_aes_xts_ctx { + struct crypto_aes_ctx key1; + struct crypto_aes_ctx __aligned(8) key2; +}; + +static int xts_set_key(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + int ret; + + ret = xts_verify_key(tfm, in_key, key_len); + if (ret) + return ret; + + ret = ce_aes_expandkey(&ctx->key1, in_key, key_len / 2); + if (!ret) + ret = ce_aes_expandkey(&ctx->key2, &in_key[key_len / 2], + key_len / 2); + if (!ret) + return 0; + + crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; +} + +static int ecb_encrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int blocks; + int err; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + ce_aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key_enc, num_rounds(ctx), blocks); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + kernel_neon_end(); + return err; +} + +static int ecb_decrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int blocks; + int err; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + ce_aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key_dec, num_rounds(ctx), blocks); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + kernel_neon_end(); + return err; +} + +static int cbc_encrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int blocks; + int err; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + ce_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key_enc, num_rounds(ctx), blocks, + walk.iv); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + kernel_neon_end(); + return err; +} + +static int cbc_decrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int blocks; + int err; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + ce_aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key_dec, num_rounds(ctx), blocks, + walk.iv); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + kernel_neon_end(); + return err; +} + +static int ctr_encrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + int err, blocks; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + ce_aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key_enc, num_rounds(ctx), blocks, + walk.iv); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + if (walk.nbytes) { + u8 __aligned(8) tail[AES_BLOCK_SIZE]; + unsigned int nbytes = walk.nbytes; + u8 *tdst = walk.dst.virt.addr; + u8 *tsrc = walk.src.virt.addr; + + /* + * Tell aes_ctr_encrypt() to process a tail block. + */ + blocks = -1; + + ce_aes_ctr_encrypt(tail, NULL, (u8 *)ctx->key_enc, + num_rounds(ctx), blocks, walk.iv); + crypto_xor_cpy(tdst, tsrc, tail, nbytes); + err = skcipher_walk_done(&walk, 0); + } + kernel_neon_end(); + + return err; +} + +static int xts_encrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + int err, first, rounds = num_rounds(&ctx->key1); + struct skcipher_walk walk; + unsigned int blocks; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) { + ce_aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key1.key_enc, rounds, blocks, + walk.iv, (u8 *)ctx->key2.key_enc, first); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + kernel_neon_end(); + + return err; +} + +static int xts_decrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + int err, first, rounds = num_rounds(&ctx->key1); + struct skcipher_walk walk; + unsigned int blocks; + + err = skcipher_walk_virt(&walk, req, true); + + kernel_neon_begin(); + for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) { + ce_aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr, + (u8 *)ctx->key1.key_dec, rounds, blocks, + walk.iv, (u8 *)ctx->key2.key_enc, first); + err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + } + kernel_neon_end(); + + return err; +} + +static struct skcipher_alg aes_algs[] = { { + .base = { + .cra_name = "__ecb(aes)", + .cra_driver_name = "__ecb-aes-ce", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_INTERNAL, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct crypto_aes_ctx), + .cra_module = THIS_MODULE, + }, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .setkey = ce_aes_setkey, + .encrypt = ecb_encrypt, + .decrypt = ecb_decrypt, +}, { + .base = { + .cra_name = "__cbc(aes)", + .cra_driver_name = "__cbc-aes-ce", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_INTERNAL, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct crypto_aes_ctx), + .cra_module = THIS_MODULE, + }, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = ce_aes_setkey, + .encrypt = cbc_encrypt, + .decrypt = cbc_decrypt, +}, { + .base = { + .cra_name = "__ctr(aes)", + .cra_driver_name = "__ctr-aes-ce", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_INTERNAL, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct crypto_aes_ctx), + .cra_module = THIS_MODULE, + }, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .chunksize = AES_BLOCK_SIZE, + .setkey = ce_aes_setkey, + .encrypt = ctr_encrypt, + .decrypt = ctr_encrypt, +}, { + .base = { + .cra_name = "__xts(aes)", + .cra_driver_name = "__xts-aes-ce", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_INTERNAL, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct crypto_aes_xts_ctx), + .cra_module = THIS_MODULE, + }, + .min_keysize = 2 * AES_MIN_KEY_SIZE, + .max_keysize = 2 * AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = xts_set_key, + .encrypt = xts_encrypt, + .decrypt = xts_decrypt, +} }; + +static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)]; + +static void aes_exit(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(aes_simd_algs) && aes_simd_algs[i]; i++) + simd_skcipher_free(aes_simd_algs[i]); + + crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs)); +} + +static int __init aes_init(void) +{ + struct simd_skcipher_alg *simd; + const char *basename; + const char *algname; + const char *drvname; + int err; + int i; + + err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs)); + if (err) + return err; + + for (i = 0; i < ARRAY_SIZE(aes_algs); i++) { + algname = aes_algs[i].base.cra_name + 2; + drvname = aes_algs[i].base.cra_driver_name + 2; + basename = aes_algs[i].base.cra_driver_name; + simd = simd_skcipher_create_compat(algname, drvname, basename); + err = PTR_ERR(simd); + if (IS_ERR(simd)) + goto unregister_simds; + + aes_simd_algs[i] = simd; + } + + return 0; + +unregister_simds: + aes_exit(); + return err; +} + +module_cpu_feature_match(AES, aes_init); +module_exit(aes_exit); |