crypto: arm - AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions
This implements the ECB, CBC, CTR and XTS asynchronous block ciphers
using the AArch32 versions of the ARMv8 Crypto Extensions for AES.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/arm/crypto/aes-ce-glue.c b/arch/arm/crypto/aes-ce-glue.c
new file mode 100644
index 0000000..d2ee591
--- /dev/null
+++ b/arch/arm/crypto/aes-ce-glue.c
@@ -0,0 +1,520 @@
+/*
+ * 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/ablk_helper.h>
+#include <crypto/algapi.h>
+#include <linux/module.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;
+
+ rko[0] = ror32(ce_aes_sub(rki[kwords - 1]), 8);
+ rko[0] = rko[0] ^ rki[0] ^ rcon[i];
+ 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_tfm *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+ int ret;
+
+ ret = ce_aes_expandkey(ctx, in_key, key_len);
+ if (!ret)
+ return 0;
+
+ tfm->crt_flags |= 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_tfm *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct crypto_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
+ int 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;
+
+ tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+ return -EINVAL;
+}
+
+static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ struct blkcipher_walk walk;
+ unsigned int blocks;
+ int err;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ 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 = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ kernel_neon_end();
+ return err;
+}
+
+static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ struct blkcipher_walk walk;
+ unsigned int blocks;
+ int err;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ 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 = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ kernel_neon_end();
+ return err;
+}
+
+static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ struct blkcipher_walk walk;
+ unsigned int blocks;
+ int err;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ 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 = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ kernel_neon_end();
+ return err;
+}
+
+static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ struct blkcipher_walk walk;
+ unsigned int blocks;
+ int err;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ 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 = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ kernel_neon_end();
+ return err;
+}
+
+static int ctr_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ struct blkcipher_walk walk;
+ int err, blocks;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
+
+ 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);
+ nbytes -= blocks * AES_BLOCK_SIZE;
+ if (nbytes && nbytes == walk.nbytes % AES_BLOCK_SIZE)
+ break;
+ err = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ if (nbytes) {
+ u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
+ u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
+ u8 __aligned(8) tail[AES_BLOCK_SIZE];
+
+ /*
+ * Minimum alignment is 8 bytes, so if nbytes is <= 8, we need
+ * to tell aes_ctr_encrypt() to only read half a block.
+ */
+ blocks = (nbytes <= 8) ? -1 : 1;
+
+ ce_aes_ctr_encrypt(tail, tsrc, (u8 *)ctx->key_enc,
+ num_rounds(ctx), blocks, walk.iv);
+ memcpy(tdst, tail, nbytes);
+ err = blkcipher_walk_done(desc, &walk, 0);
+ }
+ kernel_neon_end();
+
+ return err;
+}
+
+static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ int err, first, rounds = num_rounds(&ctx->key1);
+ struct blkcipher_walk walk;
+ unsigned int blocks;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ 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 = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ kernel_neon_end();
+
+ return err;
+}
+
+static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct crypto_aes_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ int err, first, rounds = num_rounds(&ctx->key1);
+ struct blkcipher_walk walk;
+ unsigned int blocks;
+
+ desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt(desc, &walk);
+
+ 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 = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % AES_BLOCK_SIZE);
+ }
+ kernel_neon_end();
+
+ return err;
+}
+
+static struct crypto_alg aes_algs[] = { {
+ .cra_name = "__ecb-aes-ce",
+ .cra_driver_name = "__driver-ecb-aes-ce",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct crypto_aes_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_blkcipher = {
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ce_aes_setkey,
+ .encrypt = ecb_encrypt,
+ .decrypt = ecb_decrypt,
+ },
+}, {
+ .cra_name = "__cbc-aes-ce",
+ .cra_driver_name = "__driver-cbc-aes-ce",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct crypto_aes_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_blkcipher = {
+ .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,
+ },
+}, {
+ .cra_name = "__ctr-aes-ce",
+ .cra_driver_name = "__driver-ctr-aes-ce",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct crypto_aes_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_blkcipher = {
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ce_aes_setkey,
+ .encrypt = ctr_encrypt,
+ .decrypt = ctr_encrypt,
+ },
+}, {
+ .cra_name = "__xts-aes-ce",
+ .cra_driver_name = "__driver-xts-aes-ce",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct crypto_aes_xts_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_blkcipher = {
+ .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,
+ },
+}, {
+ .cra_name = "ecb(aes)",
+ .cra_driver_name = "ecb-aes-ce",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct async_helper_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_init = ablk_init,
+ .cra_exit = ablk_exit,
+ .cra_ablkcipher = {
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ablk_set_key,
+ .encrypt = ablk_encrypt,
+ .decrypt = ablk_decrypt,
+ }
+}, {
+ .cra_name = "cbc(aes)",
+ .cra_driver_name = "cbc-aes-ce",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct async_helper_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_init = ablk_init,
+ .cra_exit = ablk_exit,
+ .cra_ablkcipher = {
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ablk_set_key,
+ .encrypt = ablk_encrypt,
+ .decrypt = ablk_decrypt,
+ }
+}, {
+ .cra_name = "ctr(aes)",
+ .cra_driver_name = "ctr-aes-ce",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct async_helper_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_init = ablk_init,
+ .cra_exit = ablk_exit,
+ .cra_ablkcipher = {
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ablk_set_key,
+ .encrypt = ablk_encrypt,
+ .decrypt = ablk_decrypt,
+ }
+}, {
+ .cra_name = "xts(aes)",
+ .cra_driver_name = "xts-aes-ce",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
+ .cra_blocksize = AES_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct async_helper_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_init = ablk_init,
+ .cra_exit = ablk_exit,
+ .cra_ablkcipher = {
+ .min_keysize = 2 * AES_MIN_KEY_SIZE,
+ .max_keysize = 2 * AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ablk_set_key,
+ .encrypt = ablk_encrypt,
+ .decrypt = ablk_decrypt,
+ }
+} };
+
+static int __init aes_init(void)
+{
+ if (!(elf_hwcap2 & HWCAP2_AES))
+ return -ENODEV;
+ return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
+}
+
+static void __exit aes_exit(void)
+{
+ crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
+}
+
+module_init(aes_init);
+module_exit(aes_exit);