This AEAD uses a chacha20 ablkcipher and a poly1305 ahash to construct the
ChaCha20-Poly1305 AEAD as defined in RFC7539. It supports both synchronous and
asynchronous operations, even if we currently have no async chacha20 or poly1305
drivers.
Signed-off-by: Martin Willi <martin@xxxxxxxxxxxxxx>
---
crypto/Kconfig | 12 +
crypto/Makefile | 1 +
crypto/chacha20poly1305.c | 663 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 676 insertions(+)
create mode 100644 crypto/chacha20poly1305.c
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 5fef005..ce53ab1a 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -217,6 +217,18 @@ config CRYPTO_GCM
Support for Galois/Counter Mode (GCM) and Galois Message
Authentication Code (GMAC). Required for IPSec.
+config CRYPTO_CHACHA20POLY1305
+ tristate "ChaCha20-Poly1305 AEAD support"
+ select CRYPTO_CHACHA20
+ select CRYPTO_POLY1305
+ select CRYPTO_AEAD
+ help
+ ChaCha20-Poly1305 AEAD support, RFC7539.
+
+ Support for the AEAD wrapper using the ChaCha20 stream cipher combined
+ with the Poly1305 authenticator. It is defined in RFC7539 for use in
+ IETF protocols.
+
config CRYPTO_SEQIV
tristate "Sequence Number IV Generator"
select CRYPTO_AEAD
diff --git a/crypto/Makefile b/crypto/Makefile
index 2424c81..e6cf6a5 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_CRYPTO_XTS) += xts.o
obj-$(CONFIG_CRYPTO_CTR) += ctr.o
obj-$(CONFIG_CRYPTO_GCM) += gcm.o
obj-$(CONFIG_CRYPTO_CCM) += ccm.o
+obj-$(CONFIG_CRYPTO_CHACHA20POLY1305) += chacha20poly1305.o
obj-$(CONFIG_CRYPTO_PCRYPT) += pcrypt.o
obj-$(CONFIG_CRYPTO_CRYPTD) += cryptd.o
obj-$(CONFIG_CRYPTO_MCRYPTD) += mcryptd.o
diff --git a/crypto/chacha20poly1305.c b/crypto/chacha20poly1305.c
new file mode 100644
index 0000000..6171cf1
--- /dev/null
+++ b/crypto/chacha20poly1305.c
@@ -0,0 +1,663 @@
+/*
+ * ChaCha20-Poly1305 AEAD, RFC7539
+ *
+ * Copyright (C) 2015 Martin Willi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <crypto/internal/aead.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+#define POLY1305_BLOCK_SIZE 16
+#define POLY1305_DIGEST_SIZE 16
+#define POLY1305_KEY_SIZE 32
+#define CHACHA20_KEY_SIZE 32
+#define CHACHA20_IV_SIZE 16
+#define CHACHAPOLY_IV_SIZE 12
+
+struct chachapoly_instance_ctx {
+ struct crypto_skcipher_spawn chacha;
+ struct crypto_ahash_spawn poly;
+ unsigned int saltlen;
+};
+
+struct chachapoly_ctx {
+ struct crypto_ablkcipher *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 {
+ /* the key we generate for Poly1305 using Chacha20 */
+ u8 key[POLY1305_KEY_SIZE];
+ u8 iv[CHACHA20_IV_SIZE];
+ struct scatterlist src[1];
+ struct ablkcipher_request req; /* must be last member */
+};
+
+struct chachapoly_req_ctx {
+ /* calculated Poly1305 tag */
+ u8 tag[POLY1305_DIGEST_SIZE];
+ /* length of data to en/decrypt, without ICV */
+ unsigned int cryptlen;
+ 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)
+ 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,
+ CHACHA20_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, 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, rctx->cryptlen,
+ sizeof(rctx->tag), 1);
+ return 0;
+}
+
+static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->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;
+ int err;
+
+ chacha_iv(creq->iv, req, 1);
+
+ ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
+ chacha_decrypt_done, req);
+ ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
+ ablkcipher_request_set_crypt(&creq->req, req->src, req->dst,
+ rctx->cryptlen, creq->iv);
+ err = crypto_ablkcipher_decrypt(&creq->req);
+ if (err)
+ return err;
+
+ 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(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->data, err, poly_tail_continue);
+}
+
+static int poly_tail(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;
+ __le64 len;
+ int err;
+
+ sg_init_table(preq->src, 1);
+ len = cpu_to_le64(req->assoclen);
+ memcpy(&preq->tail.assoclen, &len, sizeof(len));
+ len = cpu_to_le64(rctx->cryptlen);
+ memcpy(&preq->tail.cryptlen, &len, sizeof(len));
+ sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail));
+
+ ahash_request_set_callback(&preq->req, aead_request_flags(req),
+ 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(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->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, bs = POLY1305_BLOCK_SIZE;
+ int err;
+
+ padlen = (bs - (rctx->cryptlen % bs)) % bs;
+ memset(preq->pad, 0, sizeof(preq->pad));
+ sg_init_table(preq->src, 1);
+ sg_set_buf(preq->src, &preq->pad, padlen);
+
+ ahash_request_set_callback(&preq->req, aead_request_flags(req),
+ 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(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->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;
+
+ ahash_request_set_callback(&preq->req, aead_request_flags(req),
+ 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(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->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, bs = POLY1305_BLOCK_SIZE;
+ int err;
+
+ padlen = (bs - (req->assoclen % bs)) % bs;
+ memset(preq->pad, 0, sizeof(preq->pad));
+ sg_init_table(preq->src, 1);
+ sg_set_buf(preq->src, preq->pad, padlen);
+
+ ahash_request_set_callback(&preq->req, aead_request_flags(req),
+ 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(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->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, aead_request_flags(req),
+ poly_ad_done, req);
+ ahash_request_set_tfm(&preq->req, ctx->poly);
+ ahash_request_set_crypt(&preq->req, req->assoc, NULL, req->assoclen);
+
+ err = crypto_ahash_update(&preq->req);
+ if (err)
+ return err;
+
+ return poly_adpad(req);
+}
+
+static void poly_init_done(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->data, err, poly_ad);
+}
+
+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, aead_request_flags(req),
+ poly_init_done, req);
+ ahash_request_set_tfm(&preq->req, ctx->poly);
+
+ err = crypto_ahash_init(&preq->req);
+ if (err)
+ return err;
+
+ return poly_ad(req);
+}
+
+static int poly_genkey_continue(struct aead_request *req)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
+ struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
+ struct chacha_req *creq = &rctx->u.chacha;
+ int err;
+
+ crypto_ahash_clear_flags(ctx->poly, CRYPTO_TFM_REQ_MASK);
+ crypto_ahash_set_flags(ctx->poly, crypto_aead_get_flags(aead) &
+ CRYPTO_TFM_REQ_MASK);
+
+ err = crypto_ahash_setkey(ctx->poly, creq->key, sizeof(creq->key));
+ crypto_aead_set_flags(aead, crypto_ahash_get_flags(ctx->poly) &
+ CRYPTO_TFM_RES_MASK);
+ if (err)
+ return err;
+
+ return poly_init(req);
+}
+
+static void poly_genkey_done(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->data, err, poly_genkey_continue);
+}
+
+static int poly_genkey(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;
+ int err;
+
+ sg_init_table(creq->src, 1);
+ memset(creq->key, 0, sizeof(creq->key));
+ sg_set_buf(creq->src, creq->key, sizeof(creq->key));
+
+ chacha_iv(creq->iv, req, 0);
+
+ ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
+ poly_genkey_done, req);
+ ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
+ ablkcipher_request_set_crypt(&creq->req, creq->src, creq->src,
+ POLY1305_KEY_SIZE, creq->iv);
+
+ err = crypto_ablkcipher_decrypt(&creq->req);
+ if (err)
+ return err;
+
+ return poly_genkey_continue(req);
+}
+
+static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
+{
+ async_done_continue(areq->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;
+ int err;
+
+ chacha_iv(creq->iv, req, 1);
+
+ ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
+ chacha_encrypt_done, req);
+ ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
+ ablkcipher_request_set_crypt(&creq->req, req->src, req->dst,
+ req->cryptlen, creq->iv);
+ err = crypto_ablkcipher_encrypt(&creq->req);
+ if (err)
+ return err;
+
+ 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;
+
+ /* encrypt call chain:
+ * - chacha_encrypt/done()
+ * - poly_genkey/done/continue()
+ * - poly_init/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);
+
+ if (req->cryptlen < POLY1305_DIGEST_SIZE)
+ return -EINVAL;
+ rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
+
+ /* decrypt call chain:
+ * - poly_genkey/done/continue()
+ * - poly_init/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);
+ int err;
+
+ if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE)
+ return -EINVAL;
+
+ keylen -= ctx->saltlen;
+ memcpy(ctx->salt, key + keylen, ctx->saltlen);
+
+ crypto_ablkcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
+ crypto_ablkcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
+ CRYPTO_TFM_REQ_MASK);
+
+ err = crypto_ablkcipher_setkey(ctx->chacha, key, keylen);
+ crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctx->chacha) &
+ CRYPTO_TFM_RES_MASK);
+ return err;
+}
+
+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_tfm *tfm)
+{
+ struct crypto_instance *inst = (void *)tfm->__crt_alg;
+ struct chachapoly_instance_ctx *ictx = crypto_instance_ctx(inst);
+ struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct crypto_ablkcipher *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_tfm_alg_alignmask(tfm);
+ align &= ~(crypto_tfm_ctx_alignment() - 1);
+ crypto_aead_set_reqsize(__crypto_aead_cast(tfm),
+ align + offsetof(struct chachapoly_req_ctx, u) +
+ max(offsetof(struct chacha_req, req) +
+ sizeof(struct ablkcipher_request) +
+ crypto_ablkcipher_reqsize(chacha),
+ offsetof(struct poly_req, req) +
+ sizeof(struct ahash_request) +
+ crypto_ahash_reqsize(poly)));
+
+ return 0;
+}
+
+static void chachapoly_exit(struct crypto_tfm *tfm)
+{
+ struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_ahash(ctx->poly);
+ crypto_free_ablkcipher(ctx->chacha);
+}
+
+static struct crypto_instance *chachapoly_alloc(struct rtattr **tb,
+ const char *name,
+ unsigned int ivsize)
+{
+ struct crypto_attr_type *algt;
+ struct crypto_instance *inst;
+ struct crypto_alg *chacha;
+ struct crypto_alg *poly;
+ struct ahash_alg *poly_ahash;
+ struct chachapoly_instance_ctx *ctx;
+ const char *chacha_name, *poly_name;
+ int err;
+
+ if (ivsize > CHACHAPOLY_IV_SIZE)
+ return ERR_PTR(-EINVAL);
+
+ algt = crypto_get_attr_type(tb);
+ if (IS_ERR(algt))
+ return ERR_CAST(algt);
+
+ if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
+ return ERR_PTR(-EINVAL);
+
+ chacha_name = crypto_attr_alg_name(tb[1]);
+ if (IS_ERR(chacha_name))
+ return ERR_CAST(chacha_name);
+ poly_name = crypto_attr_alg_name(tb[2]);
+ if (IS_ERR(poly_name))
+ return ERR_CAST(poly_name);
+
+ poly = crypto_find_alg(poly_name, &crypto_ahash_type,
+ CRYPTO_ALG_TYPE_HASH,
+ CRYPTO_ALG_TYPE_AHASH_MASK);
+ if (IS_ERR(poly))
+ return ERR_CAST(poly);
+
+ err = -ENOMEM;
+ inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+ if (!inst)
+ goto out_put_poly;
+
+ ctx = crypto_instance_ctx(inst);
+ ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
+ poly_ahash = container_of(poly, struct ahash_alg, halg.base);
+ err = crypto_init_ahash_spawn(&ctx->poly, &poly_ahash->halg, inst);
+ if (err)
+ goto err_free_inst;
+
+ crypto_set_skcipher_spawn(&ctx->chacha, inst);
+ err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0,
+ crypto_requires_sync(algt->type,
+ algt->mask));
+ if (err)
+ goto err_drop_poly;
+
+ chacha = crypto_skcipher_spawn_alg(&ctx->chacha);
+
+ err = -EINVAL;
+ /* Need 16-byte IV size, including Initial Block Counter value */
+ if (chacha->cra_ablkcipher.ivsize != CHACHA20_IV_SIZE)
+ goto out_drop_chacha;
+ /* Not a stream cipher? */
+ if (chacha->cra_blocksize != 1)
+ goto out_drop_chacha;
+
+ err = -ENAMETOOLONG;
+ if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
+ "%s(%s,%s)", name, chacha_name,
+ poly_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_drop_chacha;
+ if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+ "%s(%s,%s)", name, chacha->cra_driver_name,
+ poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_drop_chacha;
+
+ inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
+ inst->alg.cra_flags |= (chacha->cra_flags |
+ poly->cra_flags) & CRYPTO_ALG_ASYNC;
+ inst->alg.cra_priority = (chacha->cra_priority +
+ poly->cra_priority) / 2;
+ inst->alg.cra_blocksize = 1;
+ inst->alg.cra_alignmask = chacha->cra_alignmask | poly->cra_alignmask;
+ inst->alg.cra_type = &crypto_nivaead_type;
+ inst->alg.cra_aead.ivsize = ivsize;
+ inst->alg.cra_aead.maxauthsize = POLY1305_DIGEST_SIZE;
+ inst->alg.cra_ctxsize = sizeof(struct chachapoly_ctx) + ctx->saltlen;
+ inst->alg.cra_init = chachapoly_init;
+ inst->alg.cra_exit = chachapoly_exit;
+ inst->alg.cra_aead.encrypt = chachapoly_encrypt;
+ inst->alg.cra_aead.decrypt = chachapoly_decrypt;
+ inst->alg.cra_aead.setkey = chachapoly_setkey;
+ inst->alg.cra_aead.setauthsize = chachapoly_setauthsize;
+ inst->alg.cra_aead.geniv = "seqiv";
+
+out:
+ crypto_mod_put(poly);
+ return inst;
+
+out_drop_chacha:
+ crypto_drop_skcipher(&ctx->chacha);
+err_drop_poly:
+ crypto_drop_ahash(&ctx->poly);
+err_free_inst:
+ kfree(inst);
+out_put_poly:
+ inst = ERR_PTR(err);
+ goto out;
+}
+
+static struct crypto_instance *rfc7539_alloc(struct rtattr **tb)
+{
+ return chachapoly_alloc(tb, "rfc7539", 12);
+}
+
+static void chachapoly_free(struct crypto_instance *inst)
+{
+ struct chachapoly_instance_ctx *ctx = crypto_instance_ctx(inst);
+
+ crypto_drop_skcipher(&ctx->chacha);
+ crypto_drop_ahash(&ctx->poly);
+ kfree(inst);
+}
+
+static struct crypto_template rfc7539_tmpl = {
+ .name = "rfc7539",
+ .alloc = rfc7539_alloc,
+ .free = chachapoly_free,
+ .module = THIS_MODULE,
+};
+
+static int __init chacha20poly1305_module_init(void)
+{
+ return crypto_register_template(&rfc7539_tmpl);
+}
+
+static void __exit chacha20poly1305_module_exit(void)
+{
+ crypto_unregister_template(&rfc7539_tmpl);
+}
+
+module_init(chacha20poly1305_module_init);
+module_exit(chacha20poly1305_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Willi <martin@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
+MODULE_ALIAS_CRYPTO("chacha20poly1305");
+MODULE_ALIAS_CRYPTO("rfc7539");
--
1.9.1
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