diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/gcm.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/crypto/gcm.c b/crypto/gcm.c index c654713..2f5fbba 100644 --- a/crypto/gcm.c +++ b/crypto/gcm.c @@ -37,6 +37,19 @@ struct crypto_rfc4106_ctx { u8 nonce[4]; }; +struct crypto_rfc4543_ctx { + struct crypto_aead *child; + u8 nonce[4]; +}; + +struct crypto_rfc4543_req_ctx { + u8 auth_tag[16]; + struct scatterlist cipher[1]; + struct scatterlist payload[2]; + struct scatterlist assoc[2]; + struct aead_request subreq; +}; + struct crypto_gcm_ghash_ctx { unsigned int cryptlen; struct scatterlist *src; @@ -1047,6 +1060,272 @@ static struct crypto_template crypto_rfc4106_tmpl = { .module = THIS_MODULE, }; +static inline struct crypto_rfc4543_req_ctx *crypto_rfc4543_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_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; + int err; + + 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); + err = crypto_aead_setkey(child, key, keylen); + crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & + CRYPTO_TFM_RES_MASK); + + return err; +} + +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); +} + +/* this is the same as crypto_authenc_chain */ +static void crypto_rfc4543_chain(struct scatterlist *head, + struct scatterlist *sg, int chain) +{ + if (chain) { + head->length += sg->length; + sg = scatterwalk_sg_next(sg); + } + + if (sg) + scatterwalk_sg_chain(head, 2, sg); + else + sg_mark_end(head); +} + +static struct aead_request *crypto_rfc4543_crypt(struct aead_request *req, + int enc) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req); + struct aead_request *subreq = &rctx->subreq; + struct scatterlist *dst = req->dst; + struct scatterlist *cipher = rctx->cipher; + struct scatterlist *payload = rctx->payload; + struct scatterlist *assoc = rctx->assoc; + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int assoclen = req->assoclen; + struct page *dstp; + u8 *vdst; + u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child), + crypto_aead_alignmask(ctx->child) + 1); + + memcpy(iv, ctx->nonce, 4); + memcpy(iv + 4, req->iv, 8); + + /* construct cipher/plaintext */ + if (enc) + memset(rctx->auth_tag, 0, authsize); + else + scatterwalk_map_and_copy(rctx->auth_tag, dst, + req->cryptlen - authsize, + authsize, 0); + + sg_init_one(cipher, rctx->auth_tag, authsize); + + /* construct the aad */ + dstp = sg_page(dst); + vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset; + + sg_init_table(payload, 2); + sg_set_buf(payload, req->iv, 8); + crypto_rfc4543_chain(payload, dst, vdst == req->iv + 8); + assoclen += 8 + req->cryptlen - (enc ? 0 : authsize); + + sg_init_table(assoc, 2); + sg_set_page(assoc, sg_page(req->assoc), req->assoc->length, + req->assoc->offset); + crypto_rfc4543_chain(assoc, payload, 0); + + 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, cipher, cipher, enc ? 0 : authsize, iv); + aead_request_set_assoc(subreq, assoc, assoclen); + + return subreq; +} + +static int crypto_rfc4543_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req); + struct aead_request *subreq; + int err; + + subreq = crypto_rfc4543_crypt(req, 1); + err = crypto_aead_encrypt(subreq); + if (err) + return err; + + scatterwalk_map_and_copy(rctx->auth_tag, req->dst, req->cryptlen, + crypto_aead_authsize(aead), 1); + + return 0; +} + +static int crypto_rfc4543_decrypt(struct aead_request *req) +{ + req = crypto_rfc4543_crypt(req, 0); + + return crypto_aead_decrypt(req); +} + +static int crypto_rfc4543_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst); + struct crypto_rfc4543_ctx *ctx = crypto_tfm_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); + tfm->crt_aead.reqsize = sizeof(struct crypto_rfc4543_req_ctx) + + ALIGN(crypto_aead_reqsize(aead), + crypto_tfm_ctx_alignment()) + + align + 16; + + return 0; +} + +static void crypto_rfc4543_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_rfc4543_ctx *ctx = crypto_tfm_ctx(tfm); + + crypto_free_aead(ctx->child); +} + +static struct crypto_instance *crypto_rfc4543_alloc(struct rtattr **tb) +{ + struct crypto_attr_type *algt; + struct crypto_instance *inst; + struct crypto_aead_spawn *spawn; + struct crypto_alg *alg; + const char *ccm_name; + int err; + + algt = crypto_get_attr_type(tb); + err = PTR_ERR(algt); + if (IS_ERR(algt)) + return ERR_PTR(err); + + if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) + return ERR_PTR(-EINVAL); + + ccm_name = crypto_attr_alg_name(tb[1]); + err = PTR_ERR(ccm_name); + if (IS_ERR(ccm_name)) + return ERR_PTR(err); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + + spawn = crypto_instance_ctx(inst); + crypto_set_aead_spawn(spawn, inst); + err = crypto_grab_aead(spawn, ccm_name, 0, + crypto_requires_sync(algt->type, algt->mask)); + if (err) + goto out_free_inst; + + alg = crypto_aead_spawn_alg(spawn); + + err = -EINVAL; + + /* We only support 16-byte blocks. */ + if (alg->cra_aead.ivsize != 16) + goto out_drop_alg; + + /* Not a stream cipher? */ + if (alg->cra_blocksize != 1) + goto out_drop_alg; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, + "rfc4543(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME || + snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "rfc4543(%s)", alg->cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto out_drop_alg; + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; + inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; + inst->alg.cra_priority = alg->cra_priority; + inst->alg.cra_blocksize = 1; + inst->alg.cra_alignmask = alg->cra_alignmask; + inst->alg.cra_type = &crypto_nivaead_type; + + inst->alg.cra_aead.ivsize = 8; + inst->alg.cra_aead.maxauthsize = 16; + + inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx); + + inst->alg.cra_init = crypto_rfc4543_init_tfm; + inst->alg.cra_exit = crypto_rfc4543_exit_tfm; + + inst->alg.cra_aead.setkey = crypto_rfc4543_setkey; + inst->alg.cra_aead.setauthsize = crypto_rfc4543_setauthsize; + inst->alg.cra_aead.encrypt = crypto_rfc4543_encrypt; + inst->alg.cra_aead.decrypt = crypto_rfc4543_decrypt; + + inst->alg.cra_aead.geniv = "seqiv"; + +out: + return inst; + +out_drop_alg: + crypto_drop_aead(spawn); +out_free_inst: + kfree(inst); + inst = ERR_PTR(err); + goto out; +} + +static void crypto_rfc4543_free(struct crypto_instance *inst) +{ + crypto_drop_spawn(crypto_instance_ctx(inst)); + kfree(inst); +} + +static struct crypto_template crypto_rfc4543_tmpl = { + .name = "rfc4543", + .alloc = crypto_rfc4543_alloc, + .free = crypto_rfc4543_free, + .module = THIS_MODULE, +}; + static int __init crypto_gcm_module_init(void) { int err; @@ -1067,8 +1346,14 @@ static int __init crypto_gcm_module_init(void) if (err) goto out_undo_gcm; + err = crypto_register_template(&crypto_rfc4543_tmpl); + if (err) + goto out_undo_rfc4106; + return 0; +out_undo_rfc4106: + crypto_unregister_template(&crypto_rfc4106_tmpl); out_undo_gcm: crypto_unregister_template(&crypto_gcm_tmpl); out_undo_base: @@ -1081,6 +1366,7 @@ out: static void __exit crypto_gcm_module_exit(void) { kfree(gcm_zeroes); + crypto_unregister_template(&crypto_rfc4543_tmpl); crypto_unregister_template(&crypto_rfc4106_tmpl); crypto_unregister_template(&crypto_gcm_tmpl); crypto_unregister_template(&crypto_gcm_base_tmpl); @@ -1094,3 +1380,4 @@ MODULE_DESCRIPTION("Galois/Counter Mode"); MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); MODULE_ALIAS("gcm_base"); MODULE_ALIAS("rfc4106"); +MODULE_ALIAS("rfc4543"); |
