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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /crypto/ctr.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'crypto/ctr.c')
-rw-r--r-- | crypto/ctr.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/crypto/ctr.c b/crypto/ctr.c new file mode 100644 index 000000000..23c698b22 --- /dev/null +++ b/crypto/ctr.c @@ -0,0 +1,362 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * CTR: Counter mode + * + * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com> + */ + +#include <crypto/algapi.h> +#include <crypto/ctr.h> +#include <crypto/internal/cipher.h> +#include <crypto/internal/skcipher.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> + +struct crypto_rfc3686_ctx { + struct crypto_skcipher *child; + u8 nonce[CTR_RFC3686_NONCE_SIZE]; +}; + +struct crypto_rfc3686_req_ctx { + u8 iv[CTR_RFC3686_BLOCK_SIZE]; + struct skcipher_request subreq CRYPTO_MINALIGN_ATTR; +}; + +static void crypto_ctr_crypt_final(struct skcipher_walk *walk, + struct crypto_cipher *tfm) +{ + unsigned int bsize = crypto_cipher_blocksize(tfm); + unsigned long alignmask = crypto_cipher_alignmask(tfm); + u8 *ctrblk = walk->iv; + u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK]; + u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1); + u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + unsigned int nbytes = walk->nbytes; + + crypto_cipher_encrypt_one(tfm, keystream, ctrblk); + crypto_xor_cpy(dst, keystream, src, nbytes); + + crypto_inc(ctrblk, bsize); +} + +static int crypto_ctr_crypt_segment(struct skcipher_walk *walk, + struct crypto_cipher *tfm) +{ + void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = + crypto_cipher_alg(tfm)->cia_encrypt; + unsigned int bsize = crypto_cipher_blocksize(tfm); + u8 *ctrblk = walk->iv; + u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + unsigned int nbytes = walk->nbytes; + + do { + /* create keystream */ + fn(crypto_cipher_tfm(tfm), dst, ctrblk); + crypto_xor(dst, src, bsize); + + /* increment counter in counterblock */ + crypto_inc(ctrblk, bsize); + + src += bsize; + dst += bsize; + } while ((nbytes -= bsize) >= bsize); + + return nbytes; +} + +static int crypto_ctr_crypt_inplace(struct skcipher_walk *walk, + struct crypto_cipher *tfm) +{ + void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = + crypto_cipher_alg(tfm)->cia_encrypt; + unsigned int bsize = crypto_cipher_blocksize(tfm); + unsigned long alignmask = crypto_cipher_alignmask(tfm); + unsigned int nbytes = walk->nbytes; + u8 *ctrblk = walk->iv; + u8 *src = walk->src.virt.addr; + u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK]; + u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1); + + do { + /* create keystream */ + fn(crypto_cipher_tfm(tfm), keystream, ctrblk); + crypto_xor(src, keystream, bsize); + + /* increment counter in counterblock */ + crypto_inc(ctrblk, bsize); + + src += bsize; + } while ((nbytes -= bsize) >= bsize); + + return nbytes; +} + +static int crypto_ctr_crypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); + const unsigned int bsize = crypto_cipher_blocksize(cipher); + struct skcipher_walk walk; + unsigned int nbytes; + int err; + + err = skcipher_walk_virt(&walk, req, false); + + while (walk.nbytes >= bsize) { + if (walk.src.virt.addr == walk.dst.virt.addr) + nbytes = crypto_ctr_crypt_inplace(&walk, cipher); + else + nbytes = crypto_ctr_crypt_segment(&walk, cipher); + + err = skcipher_walk_done(&walk, nbytes); + } + + if (walk.nbytes) { + crypto_ctr_crypt_final(&walk, cipher); + err = skcipher_walk_done(&walk, 0); + } + + return err; +} + +static int crypto_ctr_create(struct crypto_template *tmpl, struct rtattr **tb) +{ + struct skcipher_instance *inst; + struct crypto_alg *alg; + int err; + + inst = skcipher_alloc_instance_simple(tmpl, tb); + if (IS_ERR(inst)) + return PTR_ERR(inst); + + alg = skcipher_ialg_simple(inst); + + /* Block size must be >= 4 bytes. */ + err = -EINVAL; + if (alg->cra_blocksize < 4) + goto out_free_inst; + + /* If this is false we'd fail the alignment of crypto_inc. */ + if (alg->cra_blocksize % 4) + goto out_free_inst; + + /* CTR mode is a stream cipher. */ + inst->alg.base.cra_blocksize = 1; + + /* + * To simplify the implementation, configure the skcipher walk to only + * give a partial block at the very end, never earlier. + */ + inst->alg.chunksize = alg->cra_blocksize; + + inst->alg.encrypt = crypto_ctr_crypt; + inst->alg.decrypt = crypto_ctr_crypt; + + err = skcipher_register_instance(tmpl, inst); + if (err) { +out_free_inst: + inst->free(inst); + } + + return err; +} + +static int crypto_rfc3686_setkey(struct crypto_skcipher *parent, + const u8 *key, unsigned int keylen) +{ + struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent); + struct crypto_skcipher *child = ctx->child; + + /* the nonce is stored in bytes at end of key */ + if (keylen < CTR_RFC3686_NONCE_SIZE) + return -EINVAL; + + memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE), + CTR_RFC3686_NONCE_SIZE); + + keylen -= CTR_RFC3686_NONCE_SIZE; + + crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + return crypto_skcipher_setkey(child, key, keylen); +} + +static int crypto_rfc3686_crypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm); + struct crypto_skcipher *child = ctx->child; + unsigned long align = crypto_skcipher_alignmask(tfm); + struct crypto_rfc3686_req_ctx *rctx = + (void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1); + struct skcipher_request *subreq = &rctx->subreq; + u8 *iv = rctx->iv; + + /* set up counter block */ + memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE); + memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE); + + /* initialize counter portion of counter block */ + *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) = + cpu_to_be32(1); + + skcipher_request_set_tfm(subreq, child); + skcipher_request_set_callback(subreq, req->base.flags, + req->base.complete, req->base.data); + skcipher_request_set_crypt(subreq, req->src, req->dst, + req->cryptlen, iv); + + return crypto_skcipher_encrypt(subreq); +} + +static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm) +{ + struct skcipher_instance *inst = skcipher_alg_instance(tfm); + struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst); + struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm); + struct crypto_skcipher *cipher; + unsigned long align; + unsigned int reqsize; + + cipher = crypto_spawn_skcipher(spawn); + if (IS_ERR(cipher)) + return PTR_ERR(cipher); + + ctx->child = cipher; + + align = crypto_skcipher_alignmask(tfm); + align &= ~(crypto_tfm_ctx_alignment() - 1); + reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) + + crypto_skcipher_reqsize(cipher); + crypto_skcipher_set_reqsize(tfm, reqsize); + + return 0; +} + +static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm) +{ + struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm); + + crypto_free_skcipher(ctx->child); +} + +static void crypto_rfc3686_free(struct skcipher_instance *inst) +{ + struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst); + + crypto_drop_skcipher(spawn); + kfree(inst); +} + +static int crypto_rfc3686_create(struct crypto_template *tmpl, + struct rtattr **tb) +{ + struct skcipher_instance *inst; + struct skcipher_alg *alg; + struct crypto_skcipher_spawn *spawn; + u32 mask; + int err; + + err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask); + if (err) + return err; + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return -ENOMEM; + + spawn = skcipher_instance_ctx(inst); + + err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + + alg = crypto_spawn_skcipher_alg(spawn); + + /* We only support 16-byte blocks. */ + err = -EINVAL; + if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE) + goto err_free_inst; + + /* Not a stream cipher? */ + if (alg->base.cra_blocksize != 1) + goto err_free_inst; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "rfc3686(%s)", alg->base.cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + + inst->alg.base.cra_priority = alg->base.cra_priority; + inst->alg.base.cra_blocksize = 1; + inst->alg.base.cra_alignmask = alg->base.cra_alignmask; + + inst->alg.ivsize = CTR_RFC3686_IV_SIZE; + inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg); + inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) + + CTR_RFC3686_NONCE_SIZE; + inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) + + CTR_RFC3686_NONCE_SIZE; + + inst->alg.setkey = crypto_rfc3686_setkey; + inst->alg.encrypt = crypto_rfc3686_crypt; + inst->alg.decrypt = crypto_rfc3686_crypt; + + inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx); + + inst->alg.init = crypto_rfc3686_init_tfm; + inst->alg.exit = crypto_rfc3686_exit_tfm; + + inst->free = crypto_rfc3686_free; + + err = skcipher_register_instance(tmpl, inst); + if (err) { +err_free_inst: + crypto_rfc3686_free(inst); + } + return err; +} + +static struct crypto_template crypto_ctr_tmpls[] = { + { + .name = "ctr", + .create = crypto_ctr_create, + .module = THIS_MODULE, + }, { + .name = "rfc3686", + .create = crypto_rfc3686_create, + .module = THIS_MODULE, + }, +}; + +static int __init crypto_ctr_module_init(void) +{ + return crypto_register_templates(crypto_ctr_tmpls, + ARRAY_SIZE(crypto_ctr_tmpls)); +} + +static void __exit crypto_ctr_module_exit(void) +{ + crypto_unregister_templates(crypto_ctr_tmpls, + ARRAY_SIZE(crypto_ctr_tmpls)); +} + +subsys_initcall(crypto_ctr_module_init); +module_exit(crypto_ctr_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("CTR block cipher mode of operation"); +MODULE_ALIAS_CRYPTO("rfc3686"); +MODULE_ALIAS_CRYPTO("ctr"); +MODULE_IMPORT_NS(CRYPTO_INTERNAL); |