diff options
Diffstat (limited to 'crypto/gcm.c')
| -rw-r--r-- | crypto/gcm.c | 1166 |
1 files changed, 1166 insertions, 0 deletions
diff --git a/crypto/gcm.c b/crypto/gcm.c new file mode 100644 index 000000000..4ba624450 --- /dev/null +++ b/crypto/gcm.c @@ -0,0 +1,1166 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * GCM: Galois/Counter Mode. + * + * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi> + */ + +#include <crypto/gf128mul.h> +#include <crypto/internal/aead.h> +#include <crypto/internal/skcipher.h> +#include <crypto/internal/hash.h> +#include <crypto/null.h> +#include <crypto/scatterwalk.h> +#include <crypto/gcm.h> +#include <crypto/hash.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> + +struct gcm_instance_ctx { + struct crypto_skcipher_spawn ctr; + struct crypto_ahash_spawn ghash; +}; + +struct crypto_gcm_ctx { + struct crypto_skcipher *ctr; + struct crypto_ahash *ghash; +}; + +struct crypto_rfc4106_ctx { + struct crypto_aead *child; + u8 nonce[4]; +}; + +struct crypto_rfc4106_req_ctx { + struct scatterlist src[3]; + struct scatterlist dst[3]; + struct aead_request subreq; +}; + +struct crypto_rfc4543_instance_ctx { + struct crypto_aead_spawn aead; +}; + +struct crypto_rfc4543_ctx { + struct crypto_aead *child; + struct crypto_sync_skcipher *null; + u8 nonce[4]; +}; + +struct crypto_rfc4543_req_ctx { + struct aead_request subreq; +}; + +struct crypto_gcm_ghash_ctx { + unsigned int cryptlen; + struct scatterlist *src; + int (*complete)(struct aead_request *req, u32 flags); +}; + +struct crypto_gcm_req_priv_ctx { + u8 iv[16]; + u8 auth_tag[16]; + u8 iauth_tag[16]; + struct scatterlist src[3]; + struct scatterlist dst[3]; + struct scatterlist sg; + struct crypto_gcm_ghash_ctx ghash_ctx; + union { + struct ahash_request ahreq; + struct skcipher_request skreq; + } u; +}; + +static struct { + u8 buf[16]; + struct scatterlist sg; +} *gcm_zeroes; + +static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc); + +static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( + struct aead_request *req) +{ + unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); + + return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); +} + +static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, + unsigned int keylen) +{ + struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_ahash *ghash = ctx->ghash; + struct crypto_skcipher *ctr = ctx->ctr; + struct { + be128 hash; + u8 iv[16]; + + struct crypto_wait wait; + + struct scatterlist sg[1]; + struct skcipher_request req; + } *data; + int err; + + crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) & + CRYPTO_TFM_REQ_MASK); + err = crypto_skcipher_setkey(ctr, key, keylen); + if (err) + return err; + + data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + crypto_init_wait(&data->wait); + sg_init_one(data->sg, &data->hash, sizeof(data->hash)); + skcipher_request_set_tfm(&data->req, ctr); + skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP | + CRYPTO_TFM_REQ_MAY_BACKLOG, + crypto_req_done, + &data->wait); + skcipher_request_set_crypt(&data->req, data->sg, data->sg, + sizeof(data->hash), data->iv); + + err = crypto_wait_req(crypto_skcipher_encrypt(&data->req), + &data->wait); + + if (err) + goto out; + + crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK); + crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) & + CRYPTO_TFM_REQ_MASK); + err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128)); +out: + kfree_sensitive(data); + return err; +} + +static int crypto_gcm_setauthsize(struct crypto_aead *tfm, + unsigned int authsize) +{ + return crypto_gcm_check_authsize(authsize); +} + +static void crypto_gcm_init_common(struct aead_request *req) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + __be32 counter = cpu_to_be32(1); + struct scatterlist *sg; + + memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag)); + memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE); + memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4); + + sg_init_table(pctx->src, 3); + sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag)); + sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen); + if (sg != pctx->src + 1) + sg_chain(pctx->src, 2, sg); + + if (req->src != req->dst) { + sg_init_table(pctx->dst, 3); + sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag)); + sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen); + if (sg != pctx->dst + 1) + sg_chain(pctx->dst, 2, sg); + } +} + +static void crypto_gcm_init_crypt(struct aead_request *req, + unsigned int cryptlen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct skcipher_request *skreq = &pctx->u.skreq; + struct scatterlist *dst; + + dst = req->src == req->dst ? pctx->src : pctx->dst; + + skcipher_request_set_tfm(skreq, ctx->ctr); + skcipher_request_set_crypt(skreq, pctx->src, dst, + cryptlen + sizeof(pctx->auth_tag), + pctx->iv); +} + +static inline unsigned int gcm_remain(unsigned int len) +{ + len &= 0xfU; + return len ? 16 - len : 0; +} + +static void gcm_hash_len_done(void *data, int err); + +static int gcm_hash_update(struct aead_request *req, + crypto_completion_t compl, + struct scatterlist *src, + unsigned int len, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct ahash_request *ahreq = &pctx->u.ahreq; + + ahash_request_set_callback(ahreq, flags, compl, req); + ahash_request_set_crypt(ahreq, src, NULL, len); + + return crypto_ahash_update(ahreq); +} + +static int gcm_hash_remain(struct aead_request *req, + unsigned int remain, + crypto_completion_t compl, u32 flags) +{ + return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags); +} + +static int gcm_hash_len(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct ahash_request *ahreq = &pctx->u.ahreq; + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + be128 lengths; + + lengths.a = cpu_to_be64(req->assoclen * 8); + lengths.b = cpu_to_be64(gctx->cryptlen * 8); + memcpy(pctx->iauth_tag, &lengths, 16); + sg_init_one(&pctx->sg, pctx->iauth_tag, 16); + ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req); + ahash_request_set_crypt(ahreq, &pctx->sg, + pctx->iauth_tag, sizeof(lengths)); + + return crypto_ahash_finup(ahreq); +} + +static int gcm_hash_len_continue(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + + return gctx->complete(req, flags); +} + +static void gcm_hash_len_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_hash_len_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags) +{ + return gcm_hash_len(req, flags) ?: + gcm_hash_len_continue(req, flags); +} + +static void gcm_hash_crypt_remain_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_hash_crypt_remain_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + unsigned int remain; + + remain = gcm_remain(gctx->cryptlen); + if (remain) + return gcm_hash_remain(req, remain, + gcm_hash_crypt_remain_done, flags) ?: + gcm_hash_crypt_remain_continue(req, flags); + + return gcm_hash_crypt_remain_continue(req, flags); +} + +static void gcm_hash_crypt_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_hash_crypt_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + + if (gctx->cryptlen) + return gcm_hash_update(req, gcm_hash_crypt_done, + gctx->src, gctx->cryptlen, flags) ?: + gcm_hash_crypt_continue(req, flags); + + return gcm_hash_crypt_remain_continue(req, flags); +} + +static void gcm_hash_assoc_remain_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_hash_assoc_remain_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags) +{ + unsigned int remain; + + remain = gcm_remain(req->assoclen); + if (remain) + return gcm_hash_remain(req, remain, + gcm_hash_assoc_remain_done, flags) ?: + gcm_hash_assoc_remain_continue(req, flags); + + return gcm_hash_assoc_remain_continue(req, flags); +} + +static void gcm_hash_assoc_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_hash_assoc_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int gcm_hash_init_continue(struct aead_request *req, u32 flags) +{ + if (req->assoclen) + return gcm_hash_update(req, gcm_hash_assoc_done, + req->src, req->assoclen, flags) ?: + gcm_hash_assoc_continue(req, flags); + + return gcm_hash_assoc_remain_continue(req, flags); +} + +static void gcm_hash_init_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_hash_init_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int gcm_hash(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct ahash_request *ahreq = &pctx->u.ahreq; + struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + + ahash_request_set_tfm(ahreq, ctx->ghash); + + ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req); + return crypto_ahash_init(ahreq) ?: + gcm_hash_init_continue(req, flags); +} + +static int gcm_enc_copy_hash(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_aead *aead = crypto_aead_reqtfm(req); + u8 *auth_tag = pctx->auth_tag; + + crypto_xor(auth_tag, pctx->iauth_tag, 16); + scatterwalk_map_and_copy(auth_tag, req->dst, + req->assoclen + req->cryptlen, + crypto_aead_authsize(aead), 1); + return 0; +} + +static int gcm_encrypt_continue(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + + gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst); + gctx->cryptlen = req->cryptlen; + gctx->complete = gcm_enc_copy_hash; + + return gcm_hash(req, flags); +} + +static void gcm_encrypt_done(void *data, int err) +{ + struct aead_request *req = data; + + if (err) + goto out; + + err = gcm_encrypt_continue(req, 0); + if (err == -EINPROGRESS) + return; + +out: + aead_request_complete(req, err); +} + +static int crypto_gcm_encrypt(struct aead_request *req) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct skcipher_request *skreq = &pctx->u.skreq; + u32 flags = aead_request_flags(req); + + crypto_gcm_init_common(req); + crypto_gcm_init_crypt(req, req->cryptlen); + skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req); + + return crypto_skcipher_encrypt(skreq) ?: + gcm_encrypt_continue(req, flags); +} + +static int crypto_gcm_verify(struct aead_request *req) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_aead *aead = crypto_aead_reqtfm(req); + u8 *auth_tag = pctx->auth_tag; + u8 *iauth_tag = pctx->iauth_tag; + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int cryptlen = req->cryptlen - authsize; + + crypto_xor(auth_tag, iauth_tag, 16); + scatterwalk_map_and_copy(iauth_tag, req->src, + req->assoclen + cryptlen, authsize, 0); + return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; +} + +static void gcm_decrypt_done(void *data, int err) +{ + struct aead_request *req = data; + + if (!err) + err = crypto_gcm_verify(req); + + aead_request_complete(req, err); +} + +static int gcm_dec_hash_continue(struct aead_request *req, u32 flags) +{ + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct skcipher_request *skreq = &pctx->u.skreq; + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + + crypto_gcm_init_crypt(req, gctx->cryptlen); + skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req); + return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req); +} + +static int crypto_gcm_decrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int cryptlen = req->cryptlen; + u32 flags = aead_request_flags(req); + + cryptlen -= authsize; + + crypto_gcm_init_common(req); + + gctx->src = sg_next(pctx->src); + gctx->cryptlen = cryptlen; + gctx->complete = gcm_dec_hash_continue; + + return gcm_hash(req, flags); +} + +static int crypto_gcm_init_tfm(struct crypto_aead *tfm) +{ + struct aead_instance *inst = aead_alg_instance(tfm); + struct gcm_instance_ctx *ictx = aead_instance_ctx(inst); + struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); + struct crypto_skcipher *ctr; + struct crypto_ahash *ghash; + unsigned long align; + int err; + + ghash = crypto_spawn_ahash(&ictx->ghash); + if (IS_ERR(ghash)) + return PTR_ERR(ghash); + + ctr = crypto_spawn_skcipher(&ictx->ctr); + err = PTR_ERR(ctr); + if (IS_ERR(ctr)) + goto err_free_hash; + + ctx->ctr = ctr; + ctx->ghash = ghash; + + align = crypto_aead_alignmask(tfm); + align &= ~(crypto_tfm_ctx_alignment() - 1); + crypto_aead_set_reqsize(tfm, + align + offsetof(struct crypto_gcm_req_priv_ctx, u) + + max(sizeof(struct skcipher_request) + + crypto_skcipher_reqsize(ctr), + sizeof(struct ahash_request) + + crypto_ahash_reqsize(ghash))); + + return 0; + +err_free_hash: + crypto_free_ahash(ghash); + return err; +} + +static void crypto_gcm_exit_tfm(struct crypto_aead *tfm) +{ + struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); + + crypto_free_ahash(ctx->ghash); + crypto_free_skcipher(ctx->ctr); +} + +static void crypto_gcm_free(struct aead_instance *inst) +{ + struct gcm_instance_ctx *ctx = aead_instance_ctx(inst); + + crypto_drop_skcipher(&ctx->ctr); + crypto_drop_ahash(&ctx->ghash); + kfree(inst); +} + +static int crypto_gcm_create_common(struct crypto_template *tmpl, + struct rtattr **tb, + const char *ctr_name, + const char *ghash_name) +{ + u32 mask; + struct aead_instance *inst; + struct gcm_instance_ctx *ctx; + struct skcipher_alg *ctr; + struct hash_alg_common *ghash; + int err; + + 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); + + err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst), + ghash_name, 0, mask); + if (err) + goto err_free_inst; + ghash = crypto_spawn_ahash_alg(&ctx->ghash); + + err = -EINVAL; + if (strcmp(ghash->base.cra_name, "ghash") != 0 || + ghash->digestsize != 16) + goto err_free_inst; + + err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst), + ctr_name, 0, mask); + if (err) + goto err_free_inst; + ctr = crypto_spawn_skcipher_alg(&ctx->ctr); + + /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */ + err = -EINVAL; + if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 || + crypto_skcipher_alg_ivsize(ctr) != 16 || + ctr->base.cra_blocksize != 1) + goto err_free_inst; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + + if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "gcm_base(%s,%s)", ctr->base.cra_driver_name, + ghash->base.cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + + inst->alg.base.cra_priority = (ghash->base.cra_priority + + ctr->base.cra_priority) / 2; + inst->alg.base.cra_blocksize = 1; + inst->alg.base.cra_alignmask = ghash->base.cra_alignmask | + ctr->base.cra_alignmask; + inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx); + inst->alg.ivsize = GCM_AES_IV_SIZE; + inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr); + inst->alg.maxauthsize = 16; + inst->alg.init = crypto_gcm_init_tfm; + inst->alg.exit = crypto_gcm_exit_tfm; + inst->alg.setkey = crypto_gcm_setkey; + inst->alg.setauthsize = crypto_gcm_setauthsize; + inst->alg.encrypt = crypto_gcm_encrypt; + inst->alg.decrypt = crypto_gcm_decrypt; + + inst->free = crypto_gcm_free; + + err = aead_register_instance(tmpl, inst); + if (err) { +err_free_inst: + crypto_gcm_free(inst); + } + return err; +} + +static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb) +{ + const char *cipher_name; + char ctr_name[CRYPTO_MAX_ALG_NAME]; + + cipher_name = crypto_attr_alg_name(tb[1]); + if (IS_ERR(cipher_name)) + return PTR_ERR(cipher_name); + + if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >= + CRYPTO_MAX_ALG_NAME) + return -ENAMETOOLONG; + + return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash"); +} + +static int crypto_gcm_base_create(struct crypto_template *tmpl, + struct rtattr **tb) +{ + const char *ctr_name; + const char *ghash_name; + + ctr_name = crypto_attr_alg_name(tb[1]); + if (IS_ERR(ctr_name)) + return PTR_ERR(ctr_name); + + ghash_name = crypto_attr_alg_name(tb[2]); + if (IS_ERR(ghash_name)) + return PTR_ERR(ghash_name); + + return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name); +} + +static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key, + unsigned int keylen) +{ + struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); + struct crypto_aead *child = ctx->child; + + if (keylen < 4) + return -EINVAL; + + keylen -= 4; + memcpy(ctx->nonce, key + keylen, 4); + + crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); + crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + return crypto_aead_setkey(child, key, keylen); +} + +static int crypto_rfc4106_setauthsize(struct crypto_aead *parent, + unsigned int authsize) +{ + struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); + int err; + + err = crypto_rfc4106_check_authsize(authsize); + if (err) + return err; + + return crypto_aead_setauthsize(ctx->child, authsize); +} + +static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req) +{ + struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req); + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead); + struct aead_request *subreq = &rctx->subreq; + struct crypto_aead *child = ctx->child; + struct scatterlist *sg; + u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), + crypto_aead_alignmask(child) + 1); + + scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0); + + memcpy(iv, ctx->nonce, 4); + memcpy(iv + 4, req->iv, 8); + + sg_init_table(rctx->src, 3); + sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8); + sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen); + if (sg != rctx->src + 1) + sg_chain(rctx->src, 2, sg); + + if (req->src != req->dst) { + sg_init_table(rctx->dst, 3); + sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8); + sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen); + if (sg != rctx->dst + 1) + sg_chain(rctx->dst, 2, sg); + } + + aead_request_set_tfm(subreq, child); + aead_request_set_callback(subreq, req->base.flags, req->base.complete, + req->base.data); + aead_request_set_crypt(subreq, rctx->src, + req->src == req->dst ? rctx->src : rctx->dst, + req->cryptlen, iv); + aead_request_set_ad(subreq, req->assoclen - 8); + + return subreq; +} + +static int crypto_rfc4106_encrypt(struct aead_request *req) +{ + int err; + + err = crypto_ipsec_check_assoclen(req->assoclen); + if (err) + return err; + + req = crypto_rfc4106_crypt(req); + + return crypto_aead_encrypt(req); +} + +static int crypto_rfc4106_decrypt(struct aead_request *req) +{ + int err; + + err = crypto_ipsec_check_assoclen(req->assoclen); + if (err) + return err; + + req = crypto_rfc4106_crypt(req); + + return crypto_aead_decrypt(req); +} + +static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm) +{ + struct aead_instance *inst = aead_alg_instance(tfm); + struct crypto_aead_spawn *spawn = aead_instance_ctx(inst); + struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); + struct crypto_aead *aead; + unsigned long align; + + aead = crypto_spawn_aead(spawn); + if (IS_ERR(aead)) + return PTR_ERR(aead); + + ctx->child = aead; + + align = crypto_aead_alignmask(aead); + align &= ~(crypto_tfm_ctx_alignment() - 1); + crypto_aead_set_reqsize( + tfm, + sizeof(struct crypto_rfc4106_req_ctx) + + ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + + align + 24); + + return 0; +} + +static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm) +{ + struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); + + crypto_free_aead(ctx->child); +} + +static void crypto_rfc4106_free(struct aead_instance *inst) +{ + crypto_drop_aead(aead_instance_ctx(inst)); + kfree(inst); +} + +static int crypto_rfc4106_create(struct crypto_template *tmpl, + struct rtattr **tb) +{ + u32 mask; + struct aead_instance *inst; + struct crypto_aead_spawn *spawn; + struct aead_alg *alg; + int err; + + err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); + if (err) + return err; + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return -ENOMEM; + + spawn = aead_instance_ctx(inst); + err = crypto_grab_aead(spawn, aead_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + + alg = crypto_spawn_aead_alg(spawn); + + err = -EINVAL; + + /* Underlying IV size must be 12. */ + if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_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, + "rfc4106(%s)", alg->base.cra_name) >= + CRYPTO_MAX_ALG_NAME || + snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "rfc4106(%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.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx); + + inst->alg.ivsize = GCM_RFC4106_IV_SIZE; + inst->alg.chunksize = crypto_aead_alg_chunksize(alg); + inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); + + inst->alg.init = crypto_rfc4106_init_tfm; + inst->alg.exit = crypto_rfc4106_exit_tfm; + + inst->alg.setkey = crypto_rfc4106_setkey; + inst->alg.setauthsize = crypto_rfc4106_setauthsize; + inst->alg.encrypt = crypto_rfc4106_encrypt; + inst->alg.decrypt = crypto_rfc4106_decrypt; + + inst->free = crypto_rfc4106_free; + + err = aead_register_instance(tmpl, inst); + if (err) { +err_free_inst: + crypto_rfc4106_free(inst); + } + return err; +} + +static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key, + unsigned int keylen) +{ + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); + struct crypto_aead *child = ctx->child; + + if (keylen < 4) + return -EINVAL; + + keylen -= 4; + memcpy(ctx->nonce, key + keylen, 4); + + crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); + crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + return crypto_aead_setkey(child, key, keylen); +} + +static int crypto_rfc4543_setauthsize(struct crypto_aead *parent, + unsigned int authsize) +{ + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); + + if (authsize != 16) + return -EINVAL; + + return crypto_aead_setauthsize(ctx->child, authsize); +} + +static int crypto_rfc4543_crypt(struct aead_request *req, bool enc) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req); + struct aead_request *subreq = &rctx->subreq; + unsigned int authsize = crypto_aead_authsize(aead); + u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child), + crypto_aead_alignmask(ctx->child) + 1); + int err; + + if (req->src != req->dst) { + err = crypto_rfc4543_copy_src_to_dst(req, enc); + if (err) + return err; + } + + memcpy(iv, ctx->nonce, 4); + memcpy(iv + 4, req->iv, 8); + + aead_request_set_tfm(subreq, ctx->child); + aead_request_set_callback(subreq, req->base.flags, + req->base.complete, req->base.data); + aead_request_set_crypt(subreq, req->src, req->dst, + enc ? 0 : authsize, iv); + aead_request_set_ad(subreq, req->assoclen + req->cryptlen - + subreq->cryptlen); + + return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq); +} + +static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int nbytes = req->assoclen + req->cryptlen - + (enc ? 0 : authsize); + SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null); + + skcipher_request_set_sync_tfm(nreq, ctx->null); + skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL); + skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL); + + return crypto_skcipher_encrypt(nreq); +} + +static int crypto_rfc4543_encrypt(struct aead_request *req) +{ + return crypto_ipsec_check_assoclen(req->assoclen) ?: + crypto_rfc4543_crypt(req, true); +} + +static int crypto_rfc4543_decrypt(struct aead_request *req) +{ + return crypto_ipsec_check_assoclen(req->assoclen) ?: + crypto_rfc4543_crypt(req, false); +} + +static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm) +{ + struct aead_instance *inst = aead_alg_instance(tfm); + struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst); + struct crypto_aead_spawn *spawn = &ictx->aead; + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); + struct crypto_aead *aead; + struct crypto_sync_skcipher *null; + unsigned long align; + int err = 0; + + aead = crypto_spawn_aead(spawn); + if (IS_ERR(aead)) + return PTR_ERR(aead); + + null = crypto_get_default_null_skcipher(); + err = PTR_ERR(null); + if (IS_ERR(null)) + goto err_free_aead; + + ctx->child = aead; + ctx->null = null; + + align = crypto_aead_alignmask(aead); + align &= ~(crypto_tfm_ctx_alignment() - 1); + crypto_aead_set_reqsize( + tfm, + sizeof(struct crypto_rfc4543_req_ctx) + + ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + + align + GCM_AES_IV_SIZE); + + return 0; + +err_free_aead: + crypto_free_aead(aead); + return err; +} + +static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm) +{ + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); + + crypto_free_aead(ctx->child); + crypto_put_default_null_skcipher(); +} + +static void crypto_rfc4543_free(struct aead_instance *inst) +{ + struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst); + + crypto_drop_aead(&ctx->aead); + + kfree(inst); +} + +static int crypto_rfc4543_create(struct crypto_template *tmpl, + struct rtattr **tb) +{ + u32 mask; + struct aead_instance *inst; + struct aead_alg *alg; + struct crypto_rfc4543_instance_ctx *ctx; + int err; + + 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); + err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + + alg = crypto_spawn_aead_alg(&ctx->aead); + + err = -EINVAL; + + /* Underlying IV size must be 12. */ + if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_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, + "rfc4543(%s)", alg->base.cra_name) >= + CRYPTO_MAX_ALG_NAME || + snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "rfc4543(%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.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx); + + inst->alg.ivsize = GCM_RFC4543_IV_SIZE; + inst->alg.chunksize = crypto_aead_alg_chunksize(alg); + inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); + + inst->alg.init = crypto_rfc4543_init_tfm; + inst->alg.exit = crypto_rfc4543_exit_tfm; + + inst->alg.setkey = crypto_rfc4543_setkey; + inst->alg.setauthsize = crypto_rfc4543_setauthsize; + inst->alg.encrypt = crypto_rfc4543_encrypt; + inst->alg.decrypt = crypto_rfc4543_decrypt; + + inst->free = crypto_rfc4543_free; + + err = aead_register_instance(tmpl, inst); + if (err) { +err_free_inst: + crypto_rfc4543_free(inst); + } + return err; +} + +static struct crypto_template crypto_gcm_tmpls[] = { + { + .name = "gcm_base", + .create = crypto_gcm_base_create, + .module = THIS_MODULE, + }, { + .name = "gcm", + .create = crypto_gcm_create, + .module = THIS_MODULE, + }, { + .name = "rfc4106", + .create = crypto_rfc4106_create, + .module = THIS_MODULE, + }, { + .name = "rfc4543", + .create = crypto_rfc4543_create, + .module = THIS_MODULE, + }, +}; + +static int __init crypto_gcm_module_init(void) +{ + int err; + + gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL); + if (!gcm_zeroes) + return -ENOMEM; + + sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf)); + + err = crypto_register_templates(crypto_gcm_tmpls, + ARRAY_SIZE(crypto_gcm_tmpls)); + if (err) + kfree(gcm_zeroes); + + return err; +} + +static void __exit crypto_gcm_module_exit(void) +{ + kfree(gcm_zeroes); + crypto_unregister_templates(crypto_gcm_tmpls, + ARRAY_SIZE(crypto_gcm_tmpls)); +} + +subsys_initcall(crypto_gcm_module_init); +module_exit(crypto_gcm_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Galois/Counter Mode"); +MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); +MODULE_ALIAS_CRYPTO("gcm_base"); +MODULE_ALIAS_CRYPTO("rfc4106"); +MODULE_ALIAS_CRYPTO("rfc4543"); +MODULE_ALIAS_CRYPTO("gcm"); |