From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- crypto/chacha20poly1305.c | 678 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 678 insertions(+) create mode 100644 crypto/chacha20poly1305.c (limited to 'crypto/chacha20poly1305.c') diff --git a/crypto/chacha20poly1305.c b/crypto/chacha20poly1305.c new file mode 100644 index 000000000..3a905c5d8 --- /dev/null +++ b/crypto/chacha20poly1305.c @@ -0,0 +1,678 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ChaCha20-Poly1305 AEAD, RFC7539 + * + * Copyright (C) 2015 Martin Willi + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct chachapoly_instance_ctx { + struct crypto_skcipher_spawn chacha; + struct crypto_ahash_spawn poly; + unsigned int saltlen; +}; + +struct chachapoly_ctx { + struct crypto_skcipher *chacha; + struct crypto_ahash *poly; + /* key bytes we use for the ChaCha20 IV */ + unsigned int saltlen; + u8 salt[]; +}; + +struct poly_req { + /* zero byte padding for AD/ciphertext, as needed */ + u8 pad[POLY1305_BLOCK_SIZE]; + /* tail data with AD/ciphertext lengths */ + struct { + __le64 assoclen; + __le64 cryptlen; + } tail; + struct scatterlist src[1]; + struct ahash_request req; /* must be last member */ +}; + +struct chacha_req { + u8 iv[CHACHA_IV_SIZE]; + struct scatterlist src[1]; + struct skcipher_request req; /* must be last member */ +}; + +struct chachapoly_req_ctx { + struct scatterlist src[2]; + struct scatterlist dst[2]; + /* the key we generate for Poly1305 using Chacha20 */ + u8 key[POLY1305_KEY_SIZE]; + /* calculated Poly1305 tag */ + u8 tag[POLY1305_DIGEST_SIZE]; + /* length of data to en/decrypt, without ICV */ + unsigned int cryptlen; + /* Actual AD, excluding IV */ + unsigned int assoclen; + /* request flags, with MAY_SLEEP cleared if needed */ + u32 flags; + union { + struct poly_req poly; + struct chacha_req chacha; + } u; +}; + +static inline void async_done_continue(struct aead_request *req, int err, + int (*cont)(struct aead_request *)) +{ + if (!err) { + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + + rctx->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + err = cont(req); + } + + if (err != -EINPROGRESS && err != -EBUSY) + aead_request_complete(req, err); +} + +static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + __le32 leicb = cpu_to_le32(icb); + + memcpy(iv, &leicb, sizeof(leicb)); + memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen); + memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv, + CHACHA_IV_SIZE - sizeof(leicb) - ctx->saltlen); +} + +static int poly_verify_tag(struct aead_request *req) +{ + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + u8 tag[sizeof(rctx->tag)]; + + scatterwalk_map_and_copy(tag, req->src, + req->assoclen + rctx->cryptlen, + sizeof(tag), 0); + if (crypto_memneq(tag, rctx->tag, sizeof(tag))) + return -EBADMSG; + return 0; +} + +static int poly_copy_tag(struct aead_request *req) +{ + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + + scatterwalk_map_and_copy(rctx->tag, req->dst, + req->assoclen + rctx->cryptlen, + sizeof(rctx->tag), 1); + return 0; +} + +static void chacha_decrypt_done(void *data, int err) +{ + async_done_continue(data, err, poly_verify_tag); +} + +static int chacha_decrypt(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct chacha_req *creq = &rctx->u.chacha; + struct scatterlist *src, *dst; + int err; + + if (rctx->cryptlen == 0) + goto skip; + + chacha_iv(creq->iv, req, 1); + + src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); + dst = src; + if (req->src != req->dst) + dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); + + skcipher_request_set_callback(&creq->req, rctx->flags, + chacha_decrypt_done, req); + skcipher_request_set_tfm(&creq->req, ctx->chacha); + skcipher_request_set_crypt(&creq->req, src, dst, + rctx->cryptlen, creq->iv); + err = crypto_skcipher_decrypt(&creq->req); + if (err) + return err; + +skip: + return poly_verify_tag(req); +} + +static int poly_tail_continue(struct aead_request *req) +{ + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + + if (rctx->cryptlen == req->cryptlen) /* encrypting */ + return poly_copy_tag(req); + + return chacha_decrypt(req); +} + +static void poly_tail_done(void *data, int err) +{ + async_done_continue(data, err, poly_tail_continue); +} + +static int poly_tail(struct aead_request *req) +{ + struct crypto_aead *tfm = crypto_aead_reqtfm(req); + struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + int err; + + preq->tail.assoclen = cpu_to_le64(rctx->assoclen); + preq->tail.cryptlen = cpu_to_le64(rctx->cryptlen); + sg_init_one(preq->src, &preq->tail, sizeof(preq->tail)); + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_tail_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + ahash_request_set_crypt(&preq->req, preq->src, + rctx->tag, sizeof(preq->tail)); + + err = crypto_ahash_finup(&preq->req); + if (err) + return err; + + return poly_tail_continue(req); +} + +static void poly_cipherpad_done(void *data, int err) +{ + async_done_continue(data, err, poly_tail); +} + +static int poly_cipherpad(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + unsigned int padlen; + int err; + + padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE; + memset(preq->pad, 0, sizeof(preq->pad)); + sg_init_one(preq->src, preq->pad, padlen); + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_cipherpad_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); + + err = crypto_ahash_update(&preq->req); + if (err) + return err; + + return poly_tail(req); +} + +static void poly_cipher_done(void *data, int err) +{ + async_done_continue(data, err, poly_cipherpad); +} + +static int poly_cipher(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + struct scatterlist *crypt = req->src; + int err; + + if (rctx->cryptlen == req->cryptlen) /* encrypting */ + crypt = req->dst; + + crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen); + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_cipher_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen); + + err = crypto_ahash_update(&preq->req); + if (err) + return err; + + return poly_cipherpad(req); +} + +static void poly_adpad_done(void *data, int err) +{ + async_done_continue(data, err, poly_cipher); +} + +static int poly_adpad(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + unsigned int padlen; + int err; + + padlen = -rctx->assoclen % POLY1305_BLOCK_SIZE; + memset(preq->pad, 0, sizeof(preq->pad)); + sg_init_one(preq->src, preq->pad, padlen); + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_adpad_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); + + err = crypto_ahash_update(&preq->req); + if (err) + return err; + + return poly_cipher(req); +} + +static void poly_ad_done(void *data, int err) +{ + async_done_continue(data, err, poly_adpad); +} + +static int poly_ad(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + int err; + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_ad_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen); + + err = crypto_ahash_update(&preq->req); + if (err) + return err; + + return poly_adpad(req); +} + +static void poly_setkey_done(void *data, int err) +{ + async_done_continue(data, err, poly_ad); +} + +static int poly_setkey(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + int err; + + sg_init_one(preq->src, rctx->key, sizeof(rctx->key)); + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_setkey_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key)); + + err = crypto_ahash_update(&preq->req); + if (err) + return err; + + return poly_ad(req); +} + +static void poly_init_done(void *data, int err) +{ + async_done_continue(data, err, poly_setkey); +} + +static int poly_init(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct poly_req *preq = &rctx->u.poly; + int err; + + ahash_request_set_callback(&preq->req, rctx->flags, + poly_init_done, req); + ahash_request_set_tfm(&preq->req, ctx->poly); + + err = crypto_ahash_init(&preq->req); + if (err) + return err; + + return poly_setkey(req); +} + +static void poly_genkey_done(void *data, int err) +{ + async_done_continue(data, err, poly_init); +} + +static int poly_genkey(struct aead_request *req) +{ + struct crypto_aead *tfm = crypto_aead_reqtfm(req); + struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct chacha_req *creq = &rctx->u.chacha; + int err; + + rctx->assoclen = req->assoclen; + + if (crypto_aead_ivsize(tfm) == 8) { + if (rctx->assoclen < 8) + return -EINVAL; + rctx->assoclen -= 8; + } + + memset(rctx->key, 0, sizeof(rctx->key)); + sg_init_one(creq->src, rctx->key, sizeof(rctx->key)); + + chacha_iv(creq->iv, req, 0); + + skcipher_request_set_callback(&creq->req, rctx->flags, + poly_genkey_done, req); + skcipher_request_set_tfm(&creq->req, ctx->chacha); + skcipher_request_set_crypt(&creq->req, creq->src, creq->src, + POLY1305_KEY_SIZE, creq->iv); + + err = crypto_skcipher_decrypt(&creq->req); + if (err) + return err; + + return poly_init(req); +} + +static void chacha_encrypt_done(void *data, int err) +{ + async_done_continue(data, err, poly_genkey); +} + +static int chacha_encrypt(struct aead_request *req) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + struct chacha_req *creq = &rctx->u.chacha; + struct scatterlist *src, *dst; + int err; + + if (req->cryptlen == 0) + goto skip; + + chacha_iv(creq->iv, req, 1); + + src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); + dst = src; + if (req->src != req->dst) + dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); + + skcipher_request_set_callback(&creq->req, rctx->flags, + chacha_encrypt_done, req); + skcipher_request_set_tfm(&creq->req, ctx->chacha); + skcipher_request_set_crypt(&creq->req, src, dst, + req->cryptlen, creq->iv); + err = crypto_skcipher_encrypt(&creq->req); + if (err) + return err; + +skip: + return poly_genkey(req); +} + +static int chachapoly_encrypt(struct aead_request *req) +{ + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + + rctx->cryptlen = req->cryptlen; + rctx->flags = aead_request_flags(req); + + /* encrypt call chain: + * - chacha_encrypt/done() + * - poly_genkey/done() + * - poly_init/done() + * - poly_setkey/done() + * - poly_ad/done() + * - poly_adpad/done() + * - poly_cipher/done() + * - poly_cipherpad/done() + * - poly_tail/done/continue() + * - poly_copy_tag() + */ + return chacha_encrypt(req); +} + +static int chachapoly_decrypt(struct aead_request *req) +{ + struct chachapoly_req_ctx *rctx = aead_request_ctx(req); + + rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; + rctx->flags = aead_request_flags(req); + + /* decrypt call chain: + * - poly_genkey/done() + * - poly_init/done() + * - poly_setkey/done() + * - poly_ad/done() + * - poly_adpad/done() + * - poly_cipher/done() + * - poly_cipherpad/done() + * - poly_tail/done/continue() + * - chacha_decrypt/done() + * - poly_verify_tag() + */ + return poly_genkey(req); +} + +static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key, + unsigned int keylen) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); + + if (keylen != ctx->saltlen + CHACHA_KEY_SIZE) + return -EINVAL; + + keylen -= ctx->saltlen; + memcpy(ctx->salt, key + keylen, ctx->saltlen); + + crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) & + CRYPTO_TFM_REQ_MASK); + return crypto_skcipher_setkey(ctx->chacha, key, keylen); +} + +static int chachapoly_setauthsize(struct crypto_aead *tfm, + unsigned int authsize) +{ + if (authsize != POLY1305_DIGEST_SIZE) + return -EINVAL; + + return 0; +} + +static int chachapoly_init(struct crypto_aead *tfm) +{ + struct aead_instance *inst = aead_alg_instance(tfm); + struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst); + struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); + struct crypto_skcipher *chacha; + struct crypto_ahash *poly; + unsigned long align; + + poly = crypto_spawn_ahash(&ictx->poly); + if (IS_ERR(poly)) + return PTR_ERR(poly); + + chacha = crypto_spawn_skcipher(&ictx->chacha); + if (IS_ERR(chacha)) { + crypto_free_ahash(poly); + return PTR_ERR(chacha); + } + + ctx->chacha = chacha; + ctx->poly = poly; + ctx->saltlen = ictx->saltlen; + + align = crypto_aead_alignmask(tfm); + align &= ~(crypto_tfm_ctx_alignment() - 1); + crypto_aead_set_reqsize( + tfm, + align + offsetof(struct chachapoly_req_ctx, u) + + max(offsetof(struct chacha_req, req) + + sizeof(struct skcipher_request) + + crypto_skcipher_reqsize(chacha), + offsetof(struct poly_req, req) + + sizeof(struct ahash_request) + + crypto_ahash_reqsize(poly))); + + return 0; +} + +static void chachapoly_exit(struct crypto_aead *tfm) +{ + struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); + + crypto_free_ahash(ctx->poly); + crypto_free_skcipher(ctx->chacha); +} + +static void chachapoly_free(struct aead_instance *inst) +{ + struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst); + + crypto_drop_skcipher(&ctx->chacha); + crypto_drop_ahash(&ctx->poly); + kfree(inst); +} + +static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, + const char *name, unsigned int ivsize) +{ + u32 mask; + struct aead_instance *inst; + struct chachapoly_instance_ctx *ctx; + struct skcipher_alg *chacha; + struct hash_alg_common *poly; + int err; + + if (ivsize > CHACHAPOLY_IV_SIZE) + return -EINVAL; + + err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); + if (err) + return err; + + inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); + if (!inst) + return -ENOMEM; + ctx = aead_instance_ctx(inst); + ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; + + err = crypto_grab_skcipher(&ctx->chacha, aead_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + chacha = crypto_spawn_skcipher_alg(&ctx->chacha); + + err = crypto_grab_ahash(&ctx->poly, aead_crypto_instance(inst), + crypto_attr_alg_name(tb[2]), 0, mask); + if (err) + goto err_free_inst; + poly = crypto_spawn_ahash_alg(&ctx->poly); + + err = -EINVAL; + if (poly->digestsize != POLY1305_DIGEST_SIZE) + goto err_free_inst; + /* Need 16-byte IV size, including Initial Block Counter value */ + if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE) + goto err_free_inst; + /* Not a stream cipher? */ + if (chacha->base.cra_blocksize != 1) + goto err_free_inst; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "%s(%s,%s)", name, chacha->base.cra_name, + poly->base.cra_name) >= CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "%s(%s,%s)", name, chacha->base.cra_driver_name, + poly->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + + inst->alg.base.cra_priority = (chacha->base.cra_priority + + poly->base.cra_priority) / 2; + inst->alg.base.cra_blocksize = 1; + inst->alg.base.cra_alignmask = chacha->base.cra_alignmask | + poly->base.cra_alignmask; + inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) + + ctx->saltlen; + inst->alg.ivsize = ivsize; + inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha); + inst->alg.maxauthsize = POLY1305_DIGEST_SIZE; + inst->alg.init = chachapoly_init; + inst->alg.exit = chachapoly_exit; + inst->alg.encrypt = chachapoly_encrypt; + inst->alg.decrypt = chachapoly_decrypt; + inst->alg.setkey = chachapoly_setkey; + inst->alg.setauthsize = chachapoly_setauthsize; + + inst->free = chachapoly_free; + + err = aead_register_instance(tmpl, inst); + if (err) { +err_free_inst: + chachapoly_free(inst); + } + return err; +} + +static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb) +{ + return chachapoly_create(tmpl, tb, "rfc7539", 12); +} + +static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb) +{ + return chachapoly_create(tmpl, tb, "rfc7539esp", 8); +} + +static struct crypto_template rfc7539_tmpls[] = { + { + .name = "rfc7539", + .create = rfc7539_create, + .module = THIS_MODULE, + }, { + .name = "rfc7539esp", + .create = rfc7539esp_create, + .module = THIS_MODULE, + }, +}; + +static int __init chacha20poly1305_module_init(void) +{ + return crypto_register_templates(rfc7539_tmpls, + ARRAY_SIZE(rfc7539_tmpls)); +} + +static void __exit chacha20poly1305_module_exit(void) +{ + crypto_unregister_templates(rfc7539_tmpls, + ARRAY_SIZE(rfc7539_tmpls)); +} + +subsys_initcall(chacha20poly1305_module_init); +module_exit(chacha20poly1305_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Martin Willi "); +MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); +MODULE_ALIAS_CRYPTO("rfc7539"); +MODULE_ALIAS_CRYPTO("rfc7539esp"); -- cgit v1.2.3