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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm64/crypto/aes-ce-ccm-glue.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/crypto/aes-ce-ccm-glue.c')
-rw-r--r-- | arch/arm64/crypto/aes-ce-ccm-glue.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/arch/arm64/crypto/aes-ce-ccm-glue.c b/arch/arm64/crypto/aes-ce-ccm-glue.c new file mode 100644 index 0000000000..25cd3808ec --- /dev/null +++ b/arch/arm64/crypto/aes-ce-ccm-glue.c @@ -0,0 +1,295 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * aes-ccm-glue.c - AES-CCM transform for ARMv8 with Crypto Extensions + * + * Copyright (C) 2013 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org> + */ + +#include <asm/neon.h> +#include <asm/unaligned.h> +#include <crypto/aes.h> +#include <crypto/scatterwalk.h> +#include <crypto/internal/aead.h> +#include <crypto/internal/skcipher.h> +#include <linux/module.h> + +#include "aes-ce-setkey.h" + +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; +} + +asmlinkage u32 ce_aes_ccm_auth_data(u8 mac[], u8 const in[], u32 abytes, + u32 macp, u32 const rk[], u32 rounds); + +asmlinkage void ce_aes_ccm_encrypt(u8 out[], u8 const in[], u32 cbytes, + u32 const rk[], u32 rounds, u8 mac[], + u8 ctr[]); + +asmlinkage void ce_aes_ccm_decrypt(u8 out[], u8 const in[], u32 cbytes, + u32 const rk[], u32 rounds, u8 mac[], + u8 ctr[]); + +asmlinkage void ce_aes_ccm_final(u8 mac[], u8 const ctr[], u32 const rk[], + u32 rounds); + +static int ccm_setkey(struct crypto_aead *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct crypto_aes_ctx *ctx = crypto_aead_ctx(tfm); + + return ce_aes_expandkey(ctx, in_key, key_len); +} + +static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + if ((authsize & 1) || authsize < 4) + return -EINVAL; + return 0; +} + +static int ccm_init_mac(struct aead_request *req, u8 maciv[], u32 msglen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + __be32 *n = (__be32 *)&maciv[AES_BLOCK_SIZE - 8]; + u32 l = req->iv[0] + 1; + + /* verify that CCM dimension 'L' is set correctly in the IV */ + if (l < 2 || l > 8) + return -EINVAL; + + /* verify that msglen can in fact be represented in L bytes */ + if (l < 4 && msglen >> (8 * l)) + return -EOVERFLOW; + + /* + * Even if the CCM spec allows L values of up to 8, the Linux cryptoapi + * uses a u32 type to represent msglen so the top 4 bytes are always 0. + */ + n[0] = 0; + n[1] = cpu_to_be32(msglen); + + memcpy(maciv, req->iv, AES_BLOCK_SIZE - l); + + /* + * Meaning of byte 0 according to CCM spec (RFC 3610/NIST 800-38C) + * - bits 0..2 : max # of bytes required to represent msglen, minus 1 + * (already set by caller) + * - bits 3..5 : size of auth tag (1 => 4 bytes, 2 => 6 bytes, etc) + * - bit 6 : indicates presence of authenticate-only data + */ + maciv[0] |= (crypto_aead_authsize(aead) - 2) << 2; + if (req->assoclen) + maciv[0] |= 0x40; + + memset(&req->iv[AES_BLOCK_SIZE - l], 0, l); + return 0; +} + +static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[]) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead); + struct __packed { __be16 l; __be32 h; u16 len; } ltag; + struct scatter_walk walk; + u32 len = req->assoclen; + u32 macp = 0; + + /* prepend the AAD with a length tag */ + if (len < 0xff00) { + ltag.l = cpu_to_be16(len); + ltag.len = 2; + } else { + ltag.l = cpu_to_be16(0xfffe); + put_unaligned_be32(len, <ag.h); + ltag.len = 6; + } + + macp = ce_aes_ccm_auth_data(mac, (u8 *)<ag, ltag.len, macp, + ctx->key_enc, num_rounds(ctx)); + 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); + } + n = min_t(u32, n, SZ_4K); /* yield NEON at least every 4k */ + p = scatterwalk_map(&walk); + + macp = ce_aes_ccm_auth_data(mac, p, n, macp, ctx->key_enc, + num_rounds(ctx)); + + if (len / SZ_4K > (len - n) / SZ_4K) { + kernel_neon_end(); + kernel_neon_begin(); + } + len -= n; + + scatterwalk_unmap(p); + scatterwalk_advance(&walk, n); + scatterwalk_done(&walk, 0, len); + } while (len); +} + +static int ccm_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead); + struct skcipher_walk walk; + u8 __aligned(8) mac[AES_BLOCK_SIZE]; + u8 buf[AES_BLOCK_SIZE]; + u32 len = req->cryptlen; + int err; + + err = ccm_init_mac(req, mac, len); + if (err) + return err; + + /* preserve the original iv for the final round */ + memcpy(buf, req->iv, AES_BLOCK_SIZE); + + err = skcipher_walk_aead_encrypt(&walk, req, false); + + kernel_neon_begin(); + + if (req->assoclen) + ccm_calculate_auth_mac(req, mac); + + while (walk.nbytes) { + u32 tail = walk.nbytes % AES_BLOCK_SIZE; + bool final = walk.nbytes == walk.total; + + if (final) + tail = 0; + + ce_aes_ccm_encrypt(walk.dst.virt.addr, walk.src.virt.addr, + walk.nbytes - tail, ctx->key_enc, + num_rounds(ctx), mac, walk.iv); + + if (!final) + kernel_neon_end(); + err = skcipher_walk_done(&walk, tail); + if (!final) + kernel_neon_begin(); + } + + ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx)); + + kernel_neon_end(); + + /* copy authtag to end of dst */ + scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen, + crypto_aead_authsize(aead), 1); + + return err; +} + +static int ccm_decrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead); + unsigned int authsize = crypto_aead_authsize(aead); + struct skcipher_walk walk; + u8 __aligned(8) mac[AES_BLOCK_SIZE]; + u8 buf[AES_BLOCK_SIZE]; + u32 len = req->cryptlen - authsize; + int err; + + err = ccm_init_mac(req, mac, len); + if (err) + return err; + + /* preserve the original iv for the final round */ + memcpy(buf, req->iv, AES_BLOCK_SIZE); + + err = skcipher_walk_aead_decrypt(&walk, req, false); + + kernel_neon_begin(); + + if (req->assoclen) + ccm_calculate_auth_mac(req, mac); + + while (walk.nbytes) { + u32 tail = walk.nbytes % AES_BLOCK_SIZE; + bool final = walk.nbytes == walk.total; + + if (final) + tail = 0; + + ce_aes_ccm_decrypt(walk.dst.virt.addr, walk.src.virt.addr, + walk.nbytes - tail, ctx->key_enc, + num_rounds(ctx), mac, walk.iv); + + if (!final) + kernel_neon_end(); + err = skcipher_walk_done(&walk, tail); + if (!final) + kernel_neon_begin(); + } + + ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx)); + + kernel_neon_end(); + + if (unlikely(err)) + return err; + + /* 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(mac, buf, authsize)) + return -EBADMSG; + return 0; +} + +static struct aead_alg ccm_aes_alg = { + .base = { + .cra_name = "ccm(aes)", + .cra_driver_name = "ccm-aes-ce", + .cra_priority = 300, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct crypto_aes_ctx), + .cra_module = THIS_MODULE, + }, + .ivsize = AES_BLOCK_SIZE, + .chunksize = AES_BLOCK_SIZE, + .maxauthsize = AES_BLOCK_SIZE, + .setkey = ccm_setkey, + .setauthsize = ccm_setauthsize, + .encrypt = ccm_encrypt, + .decrypt = ccm_decrypt, +}; + +static int __init aes_mod_init(void) +{ + if (!cpu_have_named_feature(AES)) + return -ENODEV; + return crypto_register_aead(&ccm_aes_alg); +} + +static void __exit aes_mod_exit(void) +{ + crypto_unregister_aead(&ccm_aes_alg); +} + +module_init(aes_mod_init); +module_exit(aes_mod_exit); + +MODULE_DESCRIPTION("Synchronous AES in CCM mode using ARMv8 Crypto Extensions"); +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_CRYPTO("ccm(aes)"); |