mirror of https://gitee.com/openkylin/linux.git
669 lines
21 KiB
C
669 lines
21 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Adiantum length-preserving encryption mode
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*
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* Copyright 2018 Google LLC
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*/
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/*
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* Adiantum is a tweakable, length-preserving encryption mode designed for fast
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* and secure disk encryption, especially on CPUs without dedicated crypto
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* instructions. Adiantum encrypts each sector using the XChaCha12 stream
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* cipher, two passes of an ε-almost-∆-universal (ε-∆U) hash function based on
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* NH and Poly1305, and an invocation of the AES-256 block cipher on a single
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* 16-byte block. See the paper for details:
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*
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* Adiantum: length-preserving encryption for entry-level processors
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* (https://eprint.iacr.org/2018/720.pdf)
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*
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* For flexibility, this implementation also allows other ciphers:
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*
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* - Stream cipher: XChaCha12 or XChaCha20
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* - Block cipher: any with a 128-bit block size and 256-bit key
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*
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* This implementation doesn't currently allow other ε-∆U hash functions, i.e.
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* HPolyC is not supported. This is because Adiantum is ~20% faster than HPolyC
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* but still provably as secure, and also the ε-∆U hash function of HBSH is
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* formally defined to take two inputs (tweak, message) which makes it difficult
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* to wrap with the crypto_shash API. Rather, some details need to be handled
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* here. Nevertheless, if needed in the future, support for other ε-∆U hash
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* functions could be added here.
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*/
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#include <crypto/b128ops.h>
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#include <crypto/chacha.h>
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#include <crypto/internal/hash.h>
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#include <crypto/internal/poly1305.h>
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#include <crypto/internal/skcipher.h>
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#include <crypto/nhpoly1305.h>
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#include <crypto/scatterwalk.h>
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#include <linux/module.h>
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#include "internal.h"
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/*
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* Size of right-hand part of input data, in bytes; also the size of the block
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* cipher's block size and the hash function's output.
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*/
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#define BLOCKCIPHER_BLOCK_SIZE 16
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/* Size of the block cipher key (K_E) in bytes */
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#define BLOCKCIPHER_KEY_SIZE 32
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/* Size of the hash key (K_H) in bytes */
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#define HASH_KEY_SIZE (POLY1305_BLOCK_SIZE + NHPOLY1305_KEY_SIZE)
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/*
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* The specification allows variable-length tweaks, but Linux's crypto API
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* currently only allows algorithms to support a single length. The "natural"
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* tweak length for Adiantum is 16, since that fits into one Poly1305 block for
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* the best performance. But longer tweaks are useful for fscrypt, to avoid
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* needing to derive per-file keys. So instead we use two blocks, or 32 bytes.
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*/
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#define TWEAK_SIZE 32
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struct adiantum_instance_ctx {
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struct crypto_skcipher_spawn streamcipher_spawn;
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struct crypto_spawn blockcipher_spawn;
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struct crypto_shash_spawn hash_spawn;
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};
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struct adiantum_tfm_ctx {
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struct crypto_skcipher *streamcipher;
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struct crypto_cipher *blockcipher;
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struct crypto_shash *hash;
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struct poly1305_key header_hash_key;
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};
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struct adiantum_request_ctx {
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/*
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* Buffer for right-hand part of data, i.e.
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*
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* P_L => P_M => C_M => C_R when encrypting, or
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* C_R => C_M => P_M => P_L when decrypting.
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*
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* Also used to build the IV for the stream cipher.
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*/
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union {
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u8 bytes[XCHACHA_IV_SIZE];
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__le32 words[XCHACHA_IV_SIZE / sizeof(__le32)];
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le128 bignum; /* interpret as element of Z/(2^{128}Z) */
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} rbuf;
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bool enc; /* true if encrypting, false if decrypting */
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/*
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* The result of the Poly1305 ε-∆U hash function applied to
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* (bulk length, tweak)
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*/
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le128 header_hash;
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/* Sub-requests, must be last */
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union {
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struct shash_desc hash_desc;
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struct skcipher_request streamcipher_req;
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} u;
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};
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/*
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* Given the XChaCha stream key K_S, derive the block cipher key K_E and the
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* hash key K_H as follows:
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*
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* K_E || K_H || ... = XChaCha(key=K_S, nonce=1||0^191)
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*
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* Note that this denotes using bits from the XChaCha keystream, which here we
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* get indirectly by encrypting a buffer containing all 0's.
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*/
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static int adiantum_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keylen)
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{
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struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
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struct {
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u8 iv[XCHACHA_IV_SIZE];
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u8 derived_keys[BLOCKCIPHER_KEY_SIZE + HASH_KEY_SIZE];
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struct scatterlist sg;
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struct crypto_wait wait;
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struct skcipher_request req; /* must be last */
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} *data;
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u8 *keyp;
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int err;
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/* Set the stream cipher key (K_S) */
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crypto_skcipher_clear_flags(tctx->streamcipher, CRYPTO_TFM_REQ_MASK);
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crypto_skcipher_set_flags(tctx->streamcipher,
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crypto_skcipher_get_flags(tfm) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_skcipher_setkey(tctx->streamcipher, key, keylen);
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crypto_skcipher_set_flags(tfm,
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crypto_skcipher_get_flags(tctx->streamcipher) &
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CRYPTO_TFM_RES_MASK);
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if (err)
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return err;
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/* Derive the subkeys */
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data = kzalloc(sizeof(*data) +
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crypto_skcipher_reqsize(tctx->streamcipher), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->iv[0] = 1;
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sg_init_one(&data->sg, data->derived_keys, sizeof(data->derived_keys));
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crypto_init_wait(&data->wait);
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skcipher_request_set_tfm(&data->req, tctx->streamcipher);
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skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
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CRYPTO_TFM_REQ_MAY_BACKLOG,
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crypto_req_done, &data->wait);
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skcipher_request_set_crypt(&data->req, &data->sg, &data->sg,
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sizeof(data->derived_keys), data->iv);
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err = crypto_wait_req(crypto_skcipher_encrypt(&data->req), &data->wait);
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if (err)
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goto out;
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keyp = data->derived_keys;
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/* Set the block cipher key (K_E) */
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crypto_cipher_clear_flags(tctx->blockcipher, CRYPTO_TFM_REQ_MASK);
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crypto_cipher_set_flags(tctx->blockcipher,
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crypto_skcipher_get_flags(tfm) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_cipher_setkey(tctx->blockcipher, keyp,
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BLOCKCIPHER_KEY_SIZE);
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crypto_skcipher_set_flags(tfm,
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crypto_cipher_get_flags(tctx->blockcipher) &
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CRYPTO_TFM_RES_MASK);
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if (err)
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goto out;
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keyp += BLOCKCIPHER_KEY_SIZE;
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/* Set the hash key (K_H) */
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poly1305_core_setkey(&tctx->header_hash_key, keyp);
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keyp += POLY1305_BLOCK_SIZE;
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crypto_shash_clear_flags(tctx->hash, CRYPTO_TFM_REQ_MASK);
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crypto_shash_set_flags(tctx->hash, crypto_skcipher_get_flags(tfm) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_shash_setkey(tctx->hash, keyp, NHPOLY1305_KEY_SIZE);
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crypto_skcipher_set_flags(tfm, crypto_shash_get_flags(tctx->hash) &
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CRYPTO_TFM_RES_MASK);
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keyp += NHPOLY1305_KEY_SIZE;
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WARN_ON(keyp != &data->derived_keys[ARRAY_SIZE(data->derived_keys)]);
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out:
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kzfree(data);
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return err;
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}
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/* Addition in Z/(2^{128}Z) */
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static inline void le128_add(le128 *r, const le128 *v1, const le128 *v2)
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{
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u64 x = le64_to_cpu(v1->b);
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u64 y = le64_to_cpu(v2->b);
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r->b = cpu_to_le64(x + y);
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r->a = cpu_to_le64(le64_to_cpu(v1->a) + le64_to_cpu(v2->a) +
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(x + y < x));
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}
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/* Subtraction in Z/(2^{128}Z) */
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static inline void le128_sub(le128 *r, const le128 *v1, const le128 *v2)
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{
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u64 x = le64_to_cpu(v1->b);
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u64 y = le64_to_cpu(v2->b);
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r->b = cpu_to_le64(x - y);
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r->a = cpu_to_le64(le64_to_cpu(v1->a) - le64_to_cpu(v2->a) -
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(x - y > x));
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}
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/*
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* Apply the Poly1305 ε-∆U hash function to (bulk length, tweak) and save the
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* result to rctx->header_hash. This is the calculation
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*
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* H_T ← Poly1305_{K_T}(bin_{128}(|L|) || T)
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*
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* from the procedure in section 6.4 of the Adiantum paper. The resulting value
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* is reused in both the first and second hash steps. Specifically, it's added
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* to the result of an independently keyed ε-∆U hash function (for equal length
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* inputs only) taken over the left-hand part (the "bulk") of the message, to
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* give the overall Adiantum hash of the (tweak, left-hand part) pair.
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*/
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static void adiantum_hash_header(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
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struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
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const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
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struct {
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__le64 message_bits;
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__le64 padding;
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} header = {
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.message_bits = cpu_to_le64((u64)bulk_len * 8)
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};
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struct poly1305_state state;
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poly1305_core_init(&state);
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BUILD_BUG_ON(sizeof(header) % POLY1305_BLOCK_SIZE != 0);
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poly1305_core_blocks(&state, &tctx->header_hash_key,
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&header, sizeof(header) / POLY1305_BLOCK_SIZE, 1);
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BUILD_BUG_ON(TWEAK_SIZE % POLY1305_BLOCK_SIZE != 0);
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poly1305_core_blocks(&state, &tctx->header_hash_key, req->iv,
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TWEAK_SIZE / POLY1305_BLOCK_SIZE, 1);
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poly1305_core_emit(&state, &rctx->header_hash);
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}
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/* Hash the left-hand part (the "bulk") of the message using NHPoly1305 */
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static int adiantum_hash_message(struct skcipher_request *req,
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struct scatterlist *sgl, le128 *digest)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
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struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
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const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
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struct shash_desc *hash_desc = &rctx->u.hash_desc;
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struct sg_mapping_iter miter;
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unsigned int i, n;
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int err;
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hash_desc->tfm = tctx->hash;
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err = crypto_shash_init(hash_desc);
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if (err)
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return err;
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sg_miter_start(&miter, sgl, sg_nents(sgl),
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SG_MITER_FROM_SG | SG_MITER_ATOMIC);
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for (i = 0; i < bulk_len; i += n) {
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sg_miter_next(&miter);
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n = min_t(unsigned int, miter.length, bulk_len - i);
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err = crypto_shash_update(hash_desc, miter.addr, n);
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if (err)
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break;
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}
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sg_miter_stop(&miter);
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if (err)
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return err;
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return crypto_shash_final(hash_desc, (u8 *)digest);
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}
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/* Continue Adiantum encryption/decryption after the stream cipher step */
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static int adiantum_finish(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
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struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
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const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
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le128 digest;
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int err;
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/* If decrypting, decrypt C_M with the block cipher to get P_M */
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if (!rctx->enc)
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crypto_cipher_decrypt_one(tctx->blockcipher, rctx->rbuf.bytes,
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rctx->rbuf.bytes);
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/*
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* Second hash step
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* enc: C_R = C_M - H_{K_H}(T, C_L)
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* dec: P_R = P_M - H_{K_H}(T, P_L)
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*/
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err = adiantum_hash_message(req, req->dst, &digest);
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if (err)
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return err;
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le128_add(&digest, &digest, &rctx->header_hash);
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le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
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scatterwalk_map_and_copy(&rctx->rbuf.bignum, req->dst,
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bulk_len, BLOCKCIPHER_BLOCK_SIZE, 1);
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return 0;
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}
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static void adiantum_streamcipher_done(struct crypto_async_request *areq,
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int err)
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{
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struct skcipher_request *req = areq->data;
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if (!err)
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err = adiantum_finish(req);
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skcipher_request_complete(req, err);
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}
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static int adiantum_crypt(struct skcipher_request *req, bool enc)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
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struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
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const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
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unsigned int stream_len;
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le128 digest;
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int err;
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if (req->cryptlen < BLOCKCIPHER_BLOCK_SIZE)
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return -EINVAL;
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rctx->enc = enc;
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/*
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* First hash step
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* enc: P_M = P_R + H_{K_H}(T, P_L)
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* dec: C_M = C_R + H_{K_H}(T, C_L)
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*/
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adiantum_hash_header(req);
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err = adiantum_hash_message(req, req->src, &digest);
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if (err)
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return err;
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le128_add(&digest, &digest, &rctx->header_hash);
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scatterwalk_map_and_copy(&rctx->rbuf.bignum, req->src,
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bulk_len, BLOCKCIPHER_BLOCK_SIZE, 0);
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le128_add(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
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/* If encrypting, encrypt P_M with the block cipher to get C_M */
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if (enc)
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crypto_cipher_encrypt_one(tctx->blockcipher, rctx->rbuf.bytes,
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rctx->rbuf.bytes);
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/* Initialize the rest of the XChaCha IV (first part is C_M) */
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BUILD_BUG_ON(BLOCKCIPHER_BLOCK_SIZE != 16);
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BUILD_BUG_ON(XCHACHA_IV_SIZE != 32); /* nonce || stream position */
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rctx->rbuf.words[4] = cpu_to_le32(1);
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rctx->rbuf.words[5] = 0;
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rctx->rbuf.words[6] = 0;
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rctx->rbuf.words[7] = 0;
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|
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/*
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* XChaCha needs to be done on all the data except the last 16 bytes;
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* for disk encryption that usually means 4080 or 496 bytes. But ChaCha
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* implementations tend to be most efficient when passed a whole number
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* of 64-byte ChaCha blocks, or sometimes even a multiple of 256 bytes.
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* And here it doesn't matter whether the last 16 bytes are written to,
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* as the second hash step will overwrite them. Thus, round the XChaCha
|
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* length up to the next 64-byte boundary if possible.
|
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*/
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stream_len = bulk_len;
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if (round_up(stream_len, CHACHA_BLOCK_SIZE) <= req->cryptlen)
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stream_len = round_up(stream_len, CHACHA_BLOCK_SIZE);
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|
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skcipher_request_set_tfm(&rctx->u.streamcipher_req, tctx->streamcipher);
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skcipher_request_set_crypt(&rctx->u.streamcipher_req, req->src,
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req->dst, stream_len, &rctx->rbuf);
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skcipher_request_set_callback(&rctx->u.streamcipher_req,
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req->base.flags,
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adiantum_streamcipher_done, req);
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return crypto_skcipher_encrypt(&rctx->u.streamcipher_req) ?:
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adiantum_finish(req);
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}
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|
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static int adiantum_encrypt(struct skcipher_request *req)
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{
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return adiantum_crypt(req, true);
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}
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|
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static int adiantum_decrypt(struct skcipher_request *req)
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{
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return adiantum_crypt(req, false);
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}
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|
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static int adiantum_init_tfm(struct crypto_skcipher *tfm)
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{
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struct skcipher_instance *inst = skcipher_alg_instance(tfm);
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struct adiantum_instance_ctx *ictx = skcipher_instance_ctx(inst);
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struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
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struct crypto_skcipher *streamcipher;
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struct crypto_cipher *blockcipher;
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struct crypto_shash *hash;
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unsigned int subreq_size;
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int err;
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|
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streamcipher = crypto_spawn_skcipher(&ictx->streamcipher_spawn);
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if (IS_ERR(streamcipher))
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return PTR_ERR(streamcipher);
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|
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blockcipher = crypto_spawn_cipher(&ictx->blockcipher_spawn);
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if (IS_ERR(blockcipher)) {
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err = PTR_ERR(blockcipher);
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goto err_free_streamcipher;
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}
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|
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hash = crypto_spawn_shash(&ictx->hash_spawn);
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if (IS_ERR(hash)) {
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err = PTR_ERR(hash);
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goto err_free_blockcipher;
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}
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|
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tctx->streamcipher = streamcipher;
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tctx->blockcipher = blockcipher;
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tctx->hash = hash;
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BUILD_BUG_ON(offsetofend(struct adiantum_request_ctx, u) !=
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sizeof(struct adiantum_request_ctx));
|
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subreq_size = max(sizeof_field(struct adiantum_request_ctx,
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u.hash_desc) +
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crypto_shash_descsize(hash),
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sizeof_field(struct adiantum_request_ctx,
|
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u.streamcipher_req) +
|
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crypto_skcipher_reqsize(streamcipher));
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|
|
|
crypto_skcipher_set_reqsize(tfm,
|
|
offsetof(struct adiantum_request_ctx, u) +
|
|
subreq_size);
|
|
return 0;
|
|
|
|
err_free_blockcipher:
|
|
crypto_free_cipher(blockcipher);
|
|
err_free_streamcipher:
|
|
crypto_free_skcipher(streamcipher);
|
|
return err;
|
|
}
|
|
|
|
static void adiantum_exit_tfm(struct crypto_skcipher *tfm)
|
|
{
|
|
struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
|
|
|
|
crypto_free_skcipher(tctx->streamcipher);
|
|
crypto_free_cipher(tctx->blockcipher);
|
|
crypto_free_shash(tctx->hash);
|
|
}
|
|
|
|
static void adiantum_free_instance(struct skcipher_instance *inst)
|
|
{
|
|
struct adiantum_instance_ctx *ictx = skcipher_instance_ctx(inst);
|
|
|
|
crypto_drop_skcipher(&ictx->streamcipher_spawn);
|
|
crypto_drop_spawn(&ictx->blockcipher_spawn);
|
|
crypto_drop_shash(&ictx->hash_spawn);
|
|
kfree(inst);
|
|
}
|
|
|
|
/*
|
|
* Check for a supported set of inner algorithms.
|
|
* See the comment at the beginning of this file.
|
|
*/
|
|
static bool adiantum_supported_algorithms(struct skcipher_alg *streamcipher_alg,
|
|
struct crypto_alg *blockcipher_alg,
|
|
struct shash_alg *hash_alg)
|
|
{
|
|
if (strcmp(streamcipher_alg->base.cra_name, "xchacha12") != 0 &&
|
|
strcmp(streamcipher_alg->base.cra_name, "xchacha20") != 0)
|
|
return false;
|
|
|
|
if (blockcipher_alg->cra_cipher.cia_min_keysize > BLOCKCIPHER_KEY_SIZE ||
|
|
blockcipher_alg->cra_cipher.cia_max_keysize < BLOCKCIPHER_KEY_SIZE)
|
|
return false;
|
|
if (blockcipher_alg->cra_blocksize != BLOCKCIPHER_BLOCK_SIZE)
|
|
return false;
|
|
|
|
if (strcmp(hash_alg->base.cra_name, "nhpoly1305") != 0)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
|
|
{
|
|
struct crypto_attr_type *algt;
|
|
const char *streamcipher_name;
|
|
const char *blockcipher_name;
|
|
const char *nhpoly1305_name;
|
|
struct skcipher_instance *inst;
|
|
struct adiantum_instance_ctx *ictx;
|
|
struct skcipher_alg *streamcipher_alg;
|
|
struct crypto_alg *blockcipher_alg;
|
|
struct crypto_alg *_hash_alg;
|
|
struct shash_alg *hash_alg;
|
|
int err;
|
|
|
|
algt = crypto_get_attr_type(tb);
|
|
if (IS_ERR(algt))
|
|
return PTR_ERR(algt);
|
|
|
|
if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
|
|
return -EINVAL;
|
|
|
|
streamcipher_name = crypto_attr_alg_name(tb[1]);
|
|
if (IS_ERR(streamcipher_name))
|
|
return PTR_ERR(streamcipher_name);
|
|
|
|
blockcipher_name = crypto_attr_alg_name(tb[2]);
|
|
if (IS_ERR(blockcipher_name))
|
|
return PTR_ERR(blockcipher_name);
|
|
|
|
nhpoly1305_name = crypto_attr_alg_name(tb[3]);
|
|
if (nhpoly1305_name == ERR_PTR(-ENOENT))
|
|
nhpoly1305_name = "nhpoly1305";
|
|
if (IS_ERR(nhpoly1305_name))
|
|
return PTR_ERR(nhpoly1305_name);
|
|
|
|
inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
|
|
if (!inst)
|
|
return -ENOMEM;
|
|
ictx = skcipher_instance_ctx(inst);
|
|
|
|
/* Stream cipher, e.g. "xchacha12" */
|
|
crypto_set_skcipher_spawn(&ictx->streamcipher_spawn,
|
|
skcipher_crypto_instance(inst));
|
|
err = crypto_grab_skcipher(&ictx->streamcipher_spawn, streamcipher_name,
|
|
0, crypto_requires_sync(algt->type,
|
|
algt->mask));
|
|
if (err)
|
|
goto out_free_inst;
|
|
streamcipher_alg = crypto_spawn_skcipher_alg(&ictx->streamcipher_spawn);
|
|
|
|
/* Block cipher, e.g. "aes" */
|
|
crypto_set_spawn(&ictx->blockcipher_spawn,
|
|
skcipher_crypto_instance(inst));
|
|
err = crypto_grab_spawn(&ictx->blockcipher_spawn, blockcipher_name,
|
|
CRYPTO_ALG_TYPE_CIPHER, CRYPTO_ALG_TYPE_MASK);
|
|
if (err)
|
|
goto out_drop_streamcipher;
|
|
blockcipher_alg = ictx->blockcipher_spawn.alg;
|
|
|
|
/* NHPoly1305 ε-∆U hash function */
|
|
_hash_alg = crypto_alg_mod_lookup(nhpoly1305_name,
|
|
CRYPTO_ALG_TYPE_SHASH,
|
|
CRYPTO_ALG_TYPE_MASK);
|
|
if (IS_ERR(_hash_alg)) {
|
|
err = PTR_ERR(_hash_alg);
|
|
goto out_drop_blockcipher;
|
|
}
|
|
hash_alg = __crypto_shash_alg(_hash_alg);
|
|
err = crypto_init_shash_spawn(&ictx->hash_spawn, hash_alg,
|
|
skcipher_crypto_instance(inst));
|
|
if (err)
|
|
goto out_put_hash;
|
|
|
|
/* Check the set of algorithms */
|
|
if (!adiantum_supported_algorithms(streamcipher_alg, blockcipher_alg,
|
|
hash_alg)) {
|
|
pr_warn("Unsupported Adiantum instantiation: (%s,%s,%s)\n",
|
|
streamcipher_alg->base.cra_name,
|
|
blockcipher_alg->cra_name, hash_alg->base.cra_name);
|
|
err = -EINVAL;
|
|
goto out_drop_hash;
|
|
}
|
|
|
|
/* Instance fields */
|
|
|
|
err = -ENAMETOOLONG;
|
|
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
|
|
"adiantum(%s,%s)", streamcipher_alg->base.cra_name,
|
|
blockcipher_alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
|
|
goto out_drop_hash;
|
|
if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
|
|
"adiantum(%s,%s,%s)",
|
|
streamcipher_alg->base.cra_driver_name,
|
|
blockcipher_alg->cra_driver_name,
|
|
hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
|
|
goto out_drop_hash;
|
|
|
|
inst->alg.base.cra_flags = streamcipher_alg->base.cra_flags &
|
|
CRYPTO_ALG_ASYNC;
|
|
inst->alg.base.cra_blocksize = BLOCKCIPHER_BLOCK_SIZE;
|
|
inst->alg.base.cra_ctxsize = sizeof(struct adiantum_tfm_ctx);
|
|
inst->alg.base.cra_alignmask = streamcipher_alg->base.cra_alignmask |
|
|
hash_alg->base.cra_alignmask;
|
|
/*
|
|
* The block cipher is only invoked once per message, so for long
|
|
* messages (e.g. sectors for disk encryption) its performance doesn't
|
|
* matter as much as that of the stream cipher and hash function. Thus,
|
|
* weigh the block cipher's ->cra_priority less.
|
|
*/
|
|
inst->alg.base.cra_priority = (4 * streamcipher_alg->base.cra_priority +
|
|
2 * hash_alg->base.cra_priority +
|
|
blockcipher_alg->cra_priority) / 7;
|
|
|
|
inst->alg.setkey = adiantum_setkey;
|
|
inst->alg.encrypt = adiantum_encrypt;
|
|
inst->alg.decrypt = adiantum_decrypt;
|
|
inst->alg.init = adiantum_init_tfm;
|
|
inst->alg.exit = adiantum_exit_tfm;
|
|
inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(streamcipher_alg);
|
|
inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(streamcipher_alg);
|
|
inst->alg.ivsize = TWEAK_SIZE;
|
|
|
|
inst->free = adiantum_free_instance;
|
|
|
|
err = skcipher_register_instance(tmpl, inst);
|
|
if (err)
|
|
goto out_drop_hash;
|
|
|
|
crypto_mod_put(_hash_alg);
|
|
return 0;
|
|
|
|
out_drop_hash:
|
|
crypto_drop_shash(&ictx->hash_spawn);
|
|
out_put_hash:
|
|
crypto_mod_put(_hash_alg);
|
|
out_drop_blockcipher:
|
|
crypto_drop_spawn(&ictx->blockcipher_spawn);
|
|
out_drop_streamcipher:
|
|
crypto_drop_skcipher(&ictx->streamcipher_spawn);
|
|
out_free_inst:
|
|
kfree(inst);
|
|
return err;
|
|
}
|
|
|
|
/* adiantum(streamcipher_name, blockcipher_name [, nhpoly1305_name]) */
|
|
static struct crypto_template adiantum_tmpl = {
|
|
.name = "adiantum",
|
|
.create = adiantum_create,
|
|
.module = THIS_MODULE,
|
|
};
|
|
|
|
static int __init adiantum_module_init(void)
|
|
{
|
|
return crypto_register_template(&adiantum_tmpl);
|
|
}
|
|
|
|
static void __exit adiantum_module_exit(void)
|
|
{
|
|
crypto_unregister_template(&adiantum_tmpl);
|
|
}
|
|
|
|
subsys_initcall(adiantum_module_init);
|
|
module_exit(adiantum_module_exit);
|
|
|
|
MODULE_DESCRIPTION("Adiantum length-preserving encryption mode");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
|
|
MODULE_ALIAS_CRYPTO("adiantum");
|