1 files changed, 469 insertions, 0 deletions

diff --git a/crypto/authenc.c b/crypto/authenc.c
new file mode 100644
index 000000000..17f674a7c
--- /dev/null
+++ b/crypto/authenc.c
@@ -0,0 +1,469 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Authenc: Simple AEAD wrapper for IPsec
+ *
+ * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/internal/aead.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/authenc.h>
+#include <crypto/null.h>
+#include <crypto/scatterwalk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+struct authenc_instance_ctx {
+	struct crypto_ahash_spawn auth;
+	struct crypto_skcipher_spawn enc;
+	unsigned int reqoff;
+};
+
+struct crypto_authenc_ctx {
+	struct crypto_ahash *auth;
+	struct crypto_skcipher *enc;
+	struct crypto_sync_skcipher *null;
+};
+
+struct authenc_request_ctx {
+	struct scatterlist src[2];
+	struct scatterlist dst[2];
+	char tail[];
+};
+
+static void authenc_request_complete(struct aead_request *req, int err)
+{
+	if (err != -EINPROGRESS)
+		aead_request_complete(req, err);
+}
+
+int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
+			       unsigned int keylen)
+{
+	struct rtattr *rta = (struct rtattr *)key;
+	struct crypto_authenc_key_param *param;
+
+	if (!RTA_OK(rta, keylen))
+		return -EINVAL;
+	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
+		return -EINVAL;
+
+	/*
+	 * RTA_OK() didn't align the rtattr's payload when validating that it
+	 * fits in the buffer.  Yet, the keys should start on the next 4-byte
+	 * aligned boundary.  To avoid confusion, require that the rtattr
+	 * payload be exactly the param struct, which has a 4-byte aligned size.
+	 */
+	if (RTA_PAYLOAD(rta) != sizeof(*param))
+		return -EINVAL;
+	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
+
+	param = RTA_DATA(rta);
+	keys->enckeylen = be32_to_cpu(param->enckeylen);
+
+	key += rta->rta_len;
+	keylen -= rta->rta_len;
+
+	if (keylen < keys->enckeylen)
+		return -EINVAL;
+
+	keys->authkeylen = keylen - keys->enckeylen;
+	keys->authkey = key;
+	keys->enckey = key + keys->authkeylen;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
+
+static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
+				 unsigned int keylen)
+{
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+	struct crypto_ahash *auth = ctx->auth;
+	struct crypto_skcipher *enc = ctx->enc;
+	struct crypto_authenc_keys keys;
+	int err = -EINVAL;
+
+	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
+		goto out;
+
+	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
+	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
+				    CRYPTO_TFM_REQ_MASK);
+	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
+	if (err)
+		goto out;
+
+	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
+	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
+				       CRYPTO_TFM_REQ_MASK);
+	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
+out:
+	memzero_explicit(&keys, sizeof(keys));
+	return err;
+}
+
+static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	struct aead_instance *inst = aead_alg_instance(authenc);
+	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
+	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
+	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
+
+	if (err)
+		goto out;
+
+	scatterwalk_map_and_copy(ahreq->result, req->dst,
+				 req->assoclen + req->cryptlen,
+				 crypto_aead_authsize(authenc), 1);
+
+out:
+	aead_request_complete(req, err);
+}
+
+static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
+{
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	struct aead_instance *inst = aead_alg_instance(authenc);
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
+	struct crypto_ahash *auth = ctx->auth;
+	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
+	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
+	u8 *hash = areq_ctx->tail;
+	int err;
+
+	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
+			   crypto_ahash_alignmask(auth) + 1);
+
+	ahash_request_set_tfm(ahreq, auth);
+	ahash_request_set_crypt(ahreq, req->dst, hash,
+				req->assoclen + req->cryptlen);
+	ahash_request_set_callback(ahreq, flags,
+				   authenc_geniv_ahash_done, req);
+
+	err = crypto_ahash_digest(ahreq);
+	if (err)
+		return err;
+
+	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
+				 crypto_aead_authsize(authenc), 1);
+
+	return 0;
+}
+
+static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
+					int err)
+{
+	struct aead_request *areq = req->data;
+
+	if (err)
+		goto out;
+
+	err = crypto_authenc_genicv(areq, 0);
+
+out:
+	authenc_request_complete(areq, err);
+}
+
+static int crypto_authenc_copy_assoc(struct aead_request *req)
+{
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
+
+	skcipher_request_set_sync_tfm(skreq, ctx->null);
+	skcipher_request_set_callback(skreq, aead_request_flags(req),
+				      NULL, NULL);
+	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
+				   NULL);
+
+	return crypto_skcipher_encrypt(skreq);
+}
+
+static int crypto_authenc_encrypt(struct aead_request *req)
+{
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	struct aead_instance *inst = aead_alg_instance(authenc);
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
+	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
+	struct crypto_skcipher *enc = ctx->enc;
+	unsigned int cryptlen = req->cryptlen;
+	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
+						  ictx->reqoff);
+	struct scatterlist *src, *dst;
+	int err;
+
+	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
+	dst = src;
+
+	if (req->src != req->dst) {
+		err = crypto_authenc_copy_assoc(req);
+		if (err)
+			return err;
+
+		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
+	}
+
+	skcipher_request_set_tfm(skreq, enc);
+	skcipher_request_set_callback(skreq, aead_request_flags(req),
+				      crypto_authenc_encrypt_done, req);
+	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
+
+	err = crypto_skcipher_encrypt(skreq);
+	if (err)
+		return err;
+
+	return crypto_authenc_genicv(req, aead_request_flags(req));
+}
+
+static int crypto_authenc_decrypt_tail(struct aead_request *req,
+				       unsigned int flags)
+{
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	struct aead_instance *inst = aead_alg_instance(authenc);
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
+	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
+	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
+	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
+						  ictx->reqoff);
+	unsigned int authsize = crypto_aead_authsize(authenc);
+	u8 *ihash = ahreq->result + authsize;
+	struct scatterlist *src, *dst;
+
+	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
+
+	if (crypto_memneq(ihash, ahreq->result, authsize))
+		return -EBADMSG;
+
+	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
+	dst = src;
+
+	if (req->src != req->dst)
+		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
+
+	skcipher_request_set_tfm(skreq, ctx->enc);
+	skcipher_request_set_callback(skreq, flags,
+				      req->base.complete, req->base.data);
+	skcipher_request_set_crypt(skreq, src, dst,
+				   req->cryptlen - authsize, req->iv);
+
+	return crypto_skcipher_decrypt(skreq);
+}
+
+static void authenc_verify_ahash_done(struct crypto_async_request *areq,
+				      int err)
+{
+	struct aead_request *req = areq->data;
+
+	if (err)
+		goto out;
+
+	err = crypto_authenc_decrypt_tail(req, 0);
+
+out:
+	authenc_request_complete(req, err);
+}
+
+static int crypto_authenc_decrypt(struct aead_request *req)
+{
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	unsigned int authsize = crypto_aead_authsize(authenc);
+	struct aead_instance *inst = aead_alg_instance(authenc);
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
+	struct crypto_ahash *auth = ctx->auth;
+	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
+	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
+	u8 *hash = areq_ctx->tail;
+	int err;
+
+	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
+			   crypto_ahash_alignmask(auth) + 1);
+
+	ahash_request_set_tfm(ahreq, auth);
+	ahash_request_set_crypt(ahreq, req->src, hash,
+				req->assoclen + req->cryptlen - authsize);
+	ahash_request_set_callback(ahreq, aead_request_flags(req),
+				   authenc_verify_ahash_done, req);
+
+	err = crypto_ahash_digest(ahreq);
+	if (err)
+		return err;
+
+	return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
+}
+
+static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
+{
+	struct aead_instance *inst = aead_alg_instance(tfm);
+	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
+	struct crypto_ahash *auth;
+	struct crypto_skcipher *enc;
+	struct crypto_sync_skcipher *null;
+	int err;
+
+	auth = crypto_spawn_ahash(&ictx->auth);
+	if (IS_ERR(auth))
+		return PTR_ERR(auth);
+
+	enc = crypto_spawn_skcipher(&ictx->enc);
+	err = PTR_ERR(enc);
+	if (IS_ERR(enc))
+		goto err_free_ahash;
+
+	null = crypto_get_default_null_skcipher();
+	err = PTR_ERR(null);
+	if (IS_ERR(null))
+		goto err_free_skcipher;
+
+	ctx->auth = auth;
+	ctx->enc = enc;
+	ctx->null = null;
+
+	crypto_aead_set_reqsize(
+		tfm,
+		sizeof(struct authenc_request_ctx) +
+		ictx->reqoff +
+		max_t(unsigned int,
+		      crypto_ahash_reqsize(auth) +
+		      sizeof(struct ahash_request),
+		      sizeof(struct skcipher_request) +
+		      crypto_skcipher_reqsize(enc)));
+
+	return 0;
+
+err_free_skcipher:
+	crypto_free_skcipher(enc);
+err_free_ahash:
+	crypto_free_ahash(auth);
+	return err;
+}
+
+static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
+{
+	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
+
+	crypto_free_ahash(ctx->auth);
+	crypto_free_skcipher(ctx->enc);
+	crypto_put_default_null_skcipher();
+}
+
+static void crypto_authenc_free(struct aead_instance *inst)
+{
+	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
+
+	crypto_drop_skcipher(&ctx->enc);
+	crypto_drop_ahash(&ctx->auth);
+	kfree(inst);
+}
+
+static int crypto_authenc_create(struct crypto_template *tmpl,
+				 struct rtattr **tb)
+{
+	u32 mask;
+	struct aead_instance *inst;
+	struct authenc_instance_ctx *ctx;
+	struct hash_alg_common *auth;
+	struct crypto_alg *auth_base;
+	struct skcipher_alg *enc;
+	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->auth, aead_crypto_instance(inst),
+				crypto_attr_alg_name(tb[1]), 0, mask);
+	if (err)
+		goto err_free_inst;
+	auth = crypto_spawn_ahash_alg(&ctx->auth);
+	auth_base = &auth->base;
+
+	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
+				   crypto_attr_alg_name(tb[2]), 0, mask);
+	if (err)
+		goto err_free_inst;
+	enc = crypto_spawn_skcipher_alg(&ctx->enc);
+
+	ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
+			    auth_base->cra_alignmask + 1);
+
+	err = -ENAMETOOLONG;
+	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
+		     "authenc(%s,%s)", auth_base->cra_name,
+		     enc->base.cra_name) >=
+	    CRYPTO_MAX_ALG_NAME)
+		goto err_free_inst;
+
+	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+		     "authenc(%s,%s)", auth_base->cra_driver_name,
+		     enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
+		goto err_free_inst;
+
+	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
+				      auth_base->cra_priority;
+	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
+	inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
+				       enc->base.cra_alignmask;
+	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
+
+	inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
+	inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
+	inst->alg.maxauthsize = auth->digestsize;
+
+	inst->alg.init = crypto_authenc_init_tfm;
+	inst->alg.exit = crypto_authenc_exit_tfm;
+
+	inst->alg.setkey = crypto_authenc_setkey;
+	inst->alg.encrypt = crypto_authenc_encrypt;
+	inst->alg.decrypt = crypto_authenc_decrypt;
+
+	inst->free = crypto_authenc_free;
+
+	err = aead_register_instance(tmpl, inst);
+	if (err) {
+err_free_inst:
+		crypto_authenc_free(inst);
+	}
+	return err;
+}
+
+static struct crypto_template crypto_authenc_tmpl = {
+	.name = "authenc",
+	.create = crypto_authenc_create,
+	.module = THIS_MODULE,
+};
+
+static int __init crypto_authenc_module_init(void)
+{
+	return crypto_register_template(&crypto_authenc_tmpl);
+}
+
+static void __exit crypto_authenc_module_exit(void)
+{
+	crypto_unregister_template(&crypto_authenc_tmpl);
+}
+
+subsys_initcall(crypto_authenc_module_init);
+module_exit(crypto_authenc_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
+MODULE_ALIAS_CRYPTO("authenc");