Commit a298765e authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: chacha20poly1305 - Use lib/crypto poly1305 



Since the poly1305 algorithm is fixed, there is no point in going
through the Crypto API for it.  Use the lib/crypto poly1305 interface
instead.

For compatiblity keep the poly1305 parameter in the algorithm name.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 318c53ae

crypto/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -784,8 +784,8 @@ config CRYPTO_AEGIS128_SIMD 
config CRYPTO_CHACHA20POLY1305

	tristate "ChaCha20-Poly1305"

	select CRYPTO_CHACHA20

	select CRYPTO_POLY1305

	select CRYPTO_AEAD

	select CRYPTO_LIB_POLY1305

	select CRYPTO_MANAGER

	help

	  ChaCha20 stream cipher and Poly1305 authenticator combined

crypto/chacha20poly1305.c

+64 −255
Original line number Diff line number Diff line
@@ -12,36 +12,23 @@ 
#include <crypto/chacha.h>

#include <crypto/poly1305.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/module.h>

#include <linux/string.h>



struct chachapoly_instance_ctx {

	struct crypto_skcipher_spawn chacha;

	struct crypto_ahash_spawn poly;

	unsigned int saltlen;

};



struct chachapoly_ctx {

	struct crypto_skcipher *chacha;

	struct crypto_ahash *poly;

	/* key bytes we use for the ChaCha20 IV */

	unsigned int saltlen;

	u8 salt[] __counted_by(saltlen);

};



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 {

	u8 iv[CHACHA_IV_SIZE];

	struct scatterlist src[1];
@@ -62,7 +49,6 @@ struct chachapoly_req_ctx { 
	/* request flags, with MAY_SLEEP cleared if needed */

	u32 flags;

	union {

		struct poly_req poly;

		struct chacha_req chacha;

	} u;

};
@@ -105,16 +91,6 @@ static int poly_verify_tag(struct aead_request *req) 
	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,

				 req->assoclen + rctx->cryptlen,

				 sizeof(rctx->tag), 1);

	return 0;

}



static void chacha_decrypt_done(void *data, int err)

{

	async_done_continue(data, err, poly_verify_tag);
@@ -151,210 +127,76 @@ static int chacha_decrypt(struct aead_request *req) 
	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(void *data, int err)

{

	async_done_continue(data, err, poly_tail_continue);

}



static int poly_tail(struct aead_request *req)

static int poly_hash(struct aead_request *req)

{

	struct crypto_aead *tfm = crypto_aead_reqtfm(req);

	struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);

	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);

	struct poly_req *preq = &rctx->u.poly;

	int err;



	preq->tail.assoclen = cpu_to_le64(rctx->assoclen);

	preq->tail.cryptlen = cpu_to_le64(rctx->cryptlen);

	sg_init_one(preq->src, &preq->tail, sizeof(preq->tail));



	ahash_request_set_callback(&preq->req, rctx->flags,

				   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(void *data, int err)

{

	async_done_continue(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;

	const void *zp = page_address(ZERO_PAGE(0));

	struct scatterlist *sg = req->src;

	struct poly1305_desc_ctx desc;

	struct scatter_walk walk;

	struct {

		union {

			struct {

				__le64 assoclen;

				__le64 cryptlen;

			};

			u8 u8[16];

		};

	} tail;

	unsigned int padlen;

	int err;



	padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE;

	memset(preq->pad, 0, sizeof(preq->pad));

	sg_init_one(preq->src, preq->pad, padlen);



	ahash_request_set_callback(&preq->req, rctx->flags,

				   poly_cipherpad_done, req);

	ahash_request_set_tfm(&preq->req, ctx->poly);

	ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);

	unsigned int total;



	err = crypto_ahash_update(&preq->req);

	if (err)

		return err;



	return poly_tail(req);

}



static void poly_cipher_done(void *data, int err)

{

	async_done_continue(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 (sg != req->dst)

		memcpy_sglist(req->dst, sg, req->assoclen);



	if (rctx->cryptlen == req->cryptlen) /* encrypting */

		crypt = req->dst;



	crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen);

		sg = req->dst;



	ahash_request_set_callback(&preq->req, rctx->flags,

				   poly_cipher_done, req);

	ahash_request_set_tfm(&preq->req, ctx->poly);

	ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);

	poly1305_init(&desc, rctx->key);

	scatterwalk_start(&walk, sg);



	err = crypto_ahash_update(&preq->req);

	if (err)

		return err;



	return poly_cipherpad(req);

}

	total = rctx->assoclen;

	while (total) {

		unsigned int n = scatterwalk_next(&walk, total);



static void poly_adpad_done(void *data, int err)

{

	async_done_continue(data, err, poly_cipher);

		poly1305_update(&desc, walk.addr, n);

		scatterwalk_done_src(&walk, n);

		total -= n;

	}



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;

	int err;



	padlen = -rctx->assoclen % POLY1305_BLOCK_SIZE;

	memset(preq->pad, 0, sizeof(preq->pad));

	sg_init_one(preq->src, preq->pad, padlen);



	ahash_request_set_callback(&preq->req, rctx->flags,

				   poly_adpad_done, req);

	ahash_request_set_tfm(&preq->req, ctx->poly);

	ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);

	poly1305_update(&desc, zp, padlen);



	err = crypto_ahash_update(&preq->req);

	if (err)

		return err;



	return poly_cipher(req);

}



static void poly_ad_done(void *data, int err)

{

	async_done_continue(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;

	scatterwalk_skip(&walk, req->assoclen - rctx->assoclen);



	ahash_request_set_callback(&preq->req, rctx->flags,

				   poly_ad_done, req);

	ahash_request_set_tfm(&preq->req, ctx->poly);

	ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen);

	total = rctx->cryptlen;

	while (total) {

		unsigned int n = scatterwalk_next(&walk, total);



	err = crypto_ahash_update(&preq->req);

	if (err)

		return err;



	return poly_adpad(req);

		poly1305_update(&desc, walk.addr, n);

		scatterwalk_done_src(&walk, n);

		total -= n;

	}



static void poly_setkey_done(void *data, int err)

{

	async_done_continue(data, err, poly_ad);

}



static int poly_setkey(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;



	sg_init_one(preq->src, rctx->key, sizeof(rctx->key));



	ahash_request_set_callback(&preq->req, rctx->flags,

				   poly_setkey_done, req);

	ahash_request_set_tfm(&preq->req, ctx->poly);

	ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));



	err = crypto_ahash_update(&preq->req);

	if (err)

		return err;



	return poly_ad(req);

}



static void poly_init_done(void *data, int err)

{

	async_done_continue(data, err, poly_setkey);

}



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;

	padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE;

	poly1305_update(&desc, zp, padlen);



	ahash_request_set_callback(&preq->req, rctx->flags,

				   poly_init_done, req);

	ahash_request_set_tfm(&preq->req, ctx->poly);

	tail.assoclen = cpu_to_le64(rctx->assoclen);

	tail.cryptlen = cpu_to_le64(rctx->cryptlen);

	poly1305_update(&desc, tail.u8, sizeof(tail));

	memzero_explicit(&tail, sizeof(tail));

	poly1305_final(&desc, rctx->tag);



	err = crypto_ahash_init(&preq->req);

	if (err)

		return err;

	if (rctx->cryptlen != req->cryptlen)

		return chacha_decrypt(req);



	return poly_setkey(req);

	memcpy_to_scatterwalk(&walk, rctx->tag, sizeof(rctx->tag));

	return 0;

}



static void poly_genkey_done(void *data, int err)

{

	async_done_continue(data, err, poly_init);

	async_done_continue(data, err, poly_hash);

}



static int poly_genkey(struct aead_request *req)
@@ -388,7 +230,7 @@ static int poly_genkey(struct aead_request *req) 
	if (err)

		return err;



	return poly_init(req);

	return poly_hash(req);

}



static void chacha_encrypt_done(void *data, int err)
@@ -437,14 +279,7 @@ static int chachapoly_encrypt(struct aead_request *req) 
	/* encrypt call chain:

	 * - chacha_encrypt/done()

	 * - poly_genkey/done()

	 * - poly_init/done()

	 * - poly_setkey/done()

	 * - poly_ad/done()

	 * - poly_adpad/done()

	 * - poly_cipher/done()

	 * - poly_cipherpad/done()

	 * - poly_tail/done/continue()

	 * - poly_copy_tag()

	 * - poly_hash()

	 */

	return chacha_encrypt(req);

}
@@ -458,13 +293,7 @@ static int chachapoly_decrypt(struct aead_request *req) 


	/* decrypt call chain:

	 * - poly_genkey/done()

	 * - poly_init/done()

	 * - poly_setkey/done()

	 * - poly_ad/done()

	 * - poly_adpad/done()

	 * - poly_cipher/done()

	 * - poly_cipherpad/done()

	 * - poly_tail/done/continue()

	 * - poly_hash()

	 * - chacha_decrypt/done()

	 * - poly_verify_tag()

	 */
@@ -503,21 +332,13 @@ static int chachapoly_init(struct crypto_aead *tfm) 
	struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst);

	struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);

	struct crypto_skcipher *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);

	if (IS_ERR(chacha))

		return PTR_ERR(chacha);

	}



	ctx->chacha = chacha;

	ctx->poly = poly;

	ctx->saltlen = ictx->saltlen;



	align = crypto_aead_alignmask(tfm);
@@ -525,12 +346,9 @@ static int chachapoly_init(struct crypto_aead *tfm) 
	crypto_aead_set_reqsize(

		tfm,

		align + offsetof(struct chachapoly_req_ctx, u) +

		max(offsetof(struct chacha_req, req) +

		offsetof(struct chacha_req, req) +

		sizeof(struct skcipher_request) +

		    crypto_skcipher_reqsize(chacha),

		    offsetof(struct poly_req, req) +

		    sizeof(struct ahash_request) +

		    crypto_ahash_reqsize(poly)));

		crypto_skcipher_reqsize(chacha));



	return 0;

}
@@ -539,7 +357,6 @@ static void chachapoly_exit(struct crypto_aead *tfm) 
{

	struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);



	crypto_free_ahash(ctx->poly);

	crypto_free_skcipher(ctx->chacha);

}
@@ -548,7 +365,6 @@ static void chachapoly_free(struct aead_instance *inst) 
	struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst);



	crypto_drop_skcipher(&ctx->chacha);

	crypto_drop_ahash(&ctx->poly);

	kfree(inst);

}
@@ -559,7 +375,6 @@ static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, 
	struct aead_instance *inst;

	struct chachapoly_instance_ctx *ctx;

	struct skcipher_alg_common *chacha;

	struct hash_alg_common *poly;

	int err;



	if (ivsize > CHACHAPOLY_IV_SIZE)
@@ -581,14 +396,9 @@ static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, 
		goto err_free_inst;

	chacha = crypto_spawn_skcipher_alg_common(&ctx->chacha);



	err = crypto_grab_ahash(&ctx->poly, aead_crypto_instance(inst),

				crypto_attr_alg_name(tb[2]), 0, mask);

	if (err)

		goto err_free_inst;

	poly = crypto_spawn_ahash_alg(&ctx->poly);



	err = -EINVAL;

	if (poly->digestsize != POLY1305_DIGEST_SIZE)

	if (strcmp(crypto_attr_alg_name(tb[2]), "poly1305") &&

	    strcmp(crypto_attr_alg_name(tb[2]), "poly1305-generic"))

		goto err_free_inst;

	/* Need 16-byte IV size, including Initial Block Counter value */

	if (chacha->ivsize != CHACHA_IV_SIZE)
@@ -599,16 +409,15 @@ static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, 


	err = -ENAMETOOLONG;

	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,

		     "%s(%s,%s)", name, chacha->base.cra_name,

		     poly->base.cra_name) >= CRYPTO_MAX_ALG_NAME)

		     "%s(%s,poly1305)", name,

		     chacha->base.cra_name) >= CRYPTO_MAX_ALG_NAME)

		goto err_free_inst;

	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,

		     "%s(%s,%s)", name, chacha->base.cra_driver_name,

		     poly->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)

		     "%s(%s,poly1305-generic)", name,

		     chacha->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)

		goto err_free_inst;



	inst->alg.base.cra_priority = (chacha->base.cra_priority +

				       poly->base.cra_priority) / 2;

	inst->alg.base.cra_priority = chacha->base.cra_priority;

	inst->alg.base.cra_blocksize = 1;

	inst->alg.base.cra_alignmask = chacha->base.cra_alignmask;

	inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +