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	 e57121d08c
			
		
	
	
		e57121d08c
		
	
	
	
	
		
			
			If the rfc7539 template was instantiated with a hash algorithm with
digest size larger than 16 bytes (POLY1305_DIGEST_SIZE), then the digest
overran the 'tag' buffer in 'struct chachapoly_req_ctx', corrupting the
subsequent memory, including 'cryptlen'.  This caused a crash during
crypto_skcipher_decrypt().
Fix it by, when instantiating the template, requiring that the
underlying hash algorithm has the digest size expected for Poly1305.
Reproducer:
    #include <linux/if_alg.h>
    #include <sys/socket.h>
    #include <unistd.h>
    int main()
    {
            int algfd, reqfd;
            struct sockaddr_alg addr = {
                    .salg_type = "aead",
                    .salg_name = "rfc7539(chacha20,sha256)",
            };
            unsigned char buf[32] = { 0 };
            algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(algfd, (void *)&addr, sizeof(addr));
            setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, sizeof(buf));
            reqfd = accept(algfd, 0, 0);
            write(reqfd, buf, 16);
            read(reqfd, buf, 16);
    }
Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 71ebc4d1b2 ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
		
	
			
		
			
				
	
	
		
			747 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			747 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * 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 <crypto/chacha20.h>
 | |
| #include <crypto/poly1305.h>
 | |
| #include <linux/err.h>
 | |
| #include <linux/init.h>
 | |
| #include <linux/kernel.h>
 | |
| #include <linux/module.h>
 | |
| 
 | |
| #include "internal.h"
 | |
| 
 | |
| #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_skcipher *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 {
 | |
| 	u8 iv[CHACHA20_IV_SIZE];
 | |
| 	struct scatterlist src[1];
 | |
| 	struct skcipher_request req; /* must be last member */
 | |
| };
 | |
| 
 | |
| struct chachapoly_req_ctx {
 | |
| 	struct scatterlist src[2];
 | |
| 	struct scatterlist dst[2];
 | |
| 	/* the key we generate for Poly1305 using Chacha20 */
 | |
| 	u8 key[POLY1305_KEY_SIZE];
 | |
| 	/* calculated Poly1305 tag */
 | |
| 	u8 tag[POLY1305_DIGEST_SIZE];
 | |
| 	/* length of data to en/decrypt, without ICV */
 | |
| 	unsigned int cryptlen;
 | |
| 	/* Actual AD, excluding IV */
 | |
| 	unsigned int assoclen;
 | |
| 	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,
 | |
| 				 req->assoclen + 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,
 | |
| 				 req->assoclen + 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;
 | |
| 	struct scatterlist *src, *dst;
 | |
| 	int err;
 | |
| 
 | |
| 	if (rctx->cryptlen == 0)
 | |
| 		goto skip;
 | |
| 
 | |
| 	chacha_iv(creq->iv, req, 1);
 | |
| 
 | |
| 	sg_init_table(rctx->src, 2);
 | |
| 	src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
 | |
| 	dst = src;
 | |
| 
 | |
| 	if (req->src != req->dst) {
 | |
| 		sg_init_table(rctx->dst, 2);
 | |
| 		dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
 | |
| 	}
 | |
| 
 | |
| 	skcipher_request_set_callback(&creq->req, aead_request_flags(req),
 | |
| 				      chacha_decrypt_done, req);
 | |
| 	skcipher_request_set_tfm(&creq->req, ctx->chacha);
 | |
| 	skcipher_request_set_crypt(&creq->req, src, dst,
 | |
| 				   rctx->cryptlen, creq->iv);
 | |
| 	err = crypto_skcipher_decrypt(&creq->req);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| skip:
 | |
| 	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 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;
 | |
| 	__le64 len;
 | |
| 	int err;
 | |
| 
 | |
| 	sg_init_table(preq->src, 1);
 | |
| 	len = cpu_to_le64(rctx->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;
 | |
| 
 | |
| 	sg_init_table(rctx->src, 2);
 | |
| 	crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen);
 | |
| 
 | |
| 	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 - (rctx->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->src, NULL, rctx->assoclen);
 | |
| 
 | |
| 	err = crypto_ahash_update(&preq->req);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| 	return poly_adpad(req);
 | |
| }
 | |
| 
 | |
| static void poly_setkey_done(struct crypto_async_request *areq, int err)
 | |
| {
 | |
| 	async_done_continue(areq->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_table(preq->src, 1);
 | |
| 	sg_set_buf(preq->src, rctx->key, sizeof(rctx->key));
 | |
| 
 | |
| 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
 | |
| 				   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(struct crypto_async_request *areq, int err)
 | |
| {
 | |
| 	async_done_continue(areq->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;
 | |
| 
 | |
| 	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_setkey(req);
 | |
| }
 | |
| 
 | |
| static void poly_genkey_done(struct crypto_async_request *areq, int err)
 | |
| {
 | |
| 	async_done_continue(areq->data, err, poly_init);
 | |
| }
 | |
| 
 | |
| static int poly_genkey(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 chacha_req *creq = &rctx->u.chacha;
 | |
| 	int err;
 | |
| 
 | |
| 	rctx->assoclen = req->assoclen;
 | |
| 
 | |
| 	if (crypto_aead_ivsize(tfm) == 8) {
 | |
| 		if (rctx->assoclen < 8)
 | |
| 			return -EINVAL;
 | |
| 		rctx->assoclen -= 8;
 | |
| 	}
 | |
| 
 | |
| 	sg_init_table(creq->src, 1);
 | |
| 	memset(rctx->key, 0, sizeof(rctx->key));
 | |
| 	sg_set_buf(creq->src, rctx->key, sizeof(rctx->key));
 | |
| 
 | |
| 	chacha_iv(creq->iv, req, 0);
 | |
| 
 | |
| 	skcipher_request_set_callback(&creq->req, aead_request_flags(req),
 | |
| 				      poly_genkey_done, req);
 | |
| 	skcipher_request_set_tfm(&creq->req, ctx->chacha);
 | |
| 	skcipher_request_set_crypt(&creq->req, creq->src, creq->src,
 | |
| 				   POLY1305_KEY_SIZE, creq->iv);
 | |
| 
 | |
| 	err = crypto_skcipher_decrypt(&creq->req);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| 	return poly_init(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;
 | |
| 	struct scatterlist *src, *dst;
 | |
| 	int err;
 | |
| 
 | |
| 	if (req->cryptlen == 0)
 | |
| 		goto skip;
 | |
| 
 | |
| 	chacha_iv(creq->iv, req, 1);
 | |
| 
 | |
| 	sg_init_table(rctx->src, 2);
 | |
| 	src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
 | |
| 	dst = src;
 | |
| 
 | |
| 	if (req->src != req->dst) {
 | |
| 		sg_init_table(rctx->dst, 2);
 | |
| 		dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
 | |
| 	}
 | |
| 
 | |
| 	skcipher_request_set_callback(&creq->req, aead_request_flags(req),
 | |
| 				      chacha_encrypt_done, req);
 | |
| 	skcipher_request_set_tfm(&creq->req, ctx->chacha);
 | |
| 	skcipher_request_set_crypt(&creq->req, src, dst,
 | |
| 				   req->cryptlen, creq->iv);
 | |
| 	err = crypto_skcipher_encrypt(&creq->req);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| skip:
 | |
| 	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()
 | |
| 	 * - 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()
 | |
| 	 */
 | |
| 	return chacha_encrypt(req);
 | |
| }
 | |
| 
 | |
| static int chachapoly_decrypt(struct aead_request *req)
 | |
| {
 | |
| 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 | |
| 
 | |
| 	rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
 | |
| 
 | |
| 	/* 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()
 | |
| 	 * - 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_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
 | |
| 	crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
 | |
| 					       CRYPTO_TFM_REQ_MASK);
 | |
| 
 | |
| 	err = crypto_skcipher_setkey(ctx->chacha, key, keylen);
 | |
| 	crypto_aead_set_flags(aead, crypto_skcipher_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_aead *tfm)
 | |
| {
 | |
| 	struct aead_instance *inst = aead_alg_instance(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);
 | |
| 		return PTR_ERR(chacha);
 | |
| 	}
 | |
| 
 | |
| 	ctx->chacha = chacha;
 | |
| 	ctx->poly = poly;
 | |
| 	ctx->saltlen = ictx->saltlen;
 | |
| 
 | |
| 	align = crypto_aead_alignmask(tfm);
 | |
| 	align &= ~(crypto_tfm_ctx_alignment() - 1);
 | |
| 	crypto_aead_set_reqsize(
 | |
| 		tfm,
 | |
| 		align + offsetof(struct chachapoly_req_ctx, u) +
 | |
| 		max(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)));
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| 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);
 | |
| }
 | |
| 
 | |
| 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);
 | |
| }
 | |
| 
 | |
| static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
 | |
| 			     const char *name, unsigned int ivsize)
 | |
| {
 | |
| 	struct crypto_attr_type *algt;
 | |
| 	struct aead_instance *inst;
 | |
| 	struct skcipher_alg *chacha;
 | |
| 	struct crypto_alg *poly;
 | |
| 	struct hash_alg_common *poly_hash;
 | |
| 	struct chachapoly_instance_ctx *ctx;
 | |
| 	const char *chacha_name, *poly_name;
 | |
| 	int err;
 | |
| 
 | |
| 	if (ivsize > CHACHAPOLY_IV_SIZE)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	algt = crypto_get_attr_type(tb);
 | |
| 	if (IS_ERR(algt))
 | |
| 		return PTR_ERR(algt);
 | |
| 
 | |
| 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	chacha_name = crypto_attr_alg_name(tb[1]);
 | |
| 	if (IS_ERR(chacha_name))
 | |
| 		return PTR_ERR(chacha_name);
 | |
| 	poly_name = crypto_attr_alg_name(tb[2]);
 | |
| 	if (IS_ERR(poly_name))
 | |
| 		return PTR_ERR(poly_name);
 | |
| 
 | |
| 	poly = crypto_find_alg(poly_name, &crypto_ahash_type,
 | |
| 			       CRYPTO_ALG_TYPE_HASH,
 | |
| 			       CRYPTO_ALG_TYPE_AHASH_MASK |
 | |
| 			       crypto_requires_sync(algt->type,
 | |
| 						    algt->mask));
 | |
| 	if (IS_ERR(poly))
 | |
| 		return PTR_ERR(poly);
 | |
| 	poly_hash = __crypto_hash_alg_common(poly);
 | |
| 
 | |
| 	err = -EINVAL;
 | |
| 	if (poly_hash->digestsize != POLY1305_DIGEST_SIZE)
 | |
| 		goto out_put_poly;
 | |
| 
 | |
| 	err = -ENOMEM;
 | |
| 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 | |
| 	if (!inst)
 | |
| 		goto out_put_poly;
 | |
| 
 | |
| 	ctx = aead_instance_ctx(inst);
 | |
| 	ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
 | |
| 	err = crypto_init_ahash_spawn(&ctx->poly, poly_hash,
 | |
| 				      aead_crypto_instance(inst));
 | |
| 	if (err)
 | |
| 		goto err_free_inst;
 | |
| 
 | |
| 	crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(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_spawn_skcipher_alg(&ctx->chacha);
 | |
| 
 | |
| 	err = -EINVAL;
 | |
| 	/* Need 16-byte IV size, including Initial Block Counter value */
 | |
| 	if (crypto_skcipher_alg_ivsize(chacha) != CHACHA20_IV_SIZE)
 | |
| 		goto out_drop_chacha;
 | |
| 	/* Not a stream cipher? */
 | |
| 	if (chacha->base.cra_blocksize != 1)
 | |
| 		goto out_drop_chacha;
 | |
| 
 | |
| 	err = -ENAMETOOLONG;
 | |
| 	if (snprintf(inst->alg.base.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.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 | |
| 		     "%s(%s,%s)", name, chacha->base.cra_driver_name,
 | |
| 		     poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 | |
| 		goto out_drop_chacha;
 | |
| 
 | |
| 	inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) &
 | |
| 				   CRYPTO_ALG_ASYNC;
 | |
| 	inst->alg.base.cra_priority = (chacha->base.cra_priority +
 | |
| 				       poly->cra_priority) / 2;
 | |
| 	inst->alg.base.cra_blocksize = 1;
 | |
| 	inst->alg.base.cra_alignmask = chacha->base.cra_alignmask |
 | |
| 				       poly->cra_alignmask;
 | |
| 	inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +
 | |
| 				     ctx->saltlen;
 | |
| 	inst->alg.ivsize = ivsize;
 | |
| 	inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha);
 | |
| 	inst->alg.maxauthsize = POLY1305_DIGEST_SIZE;
 | |
| 	inst->alg.init = chachapoly_init;
 | |
| 	inst->alg.exit = chachapoly_exit;
 | |
| 	inst->alg.encrypt = chachapoly_encrypt;
 | |
| 	inst->alg.decrypt = chachapoly_decrypt;
 | |
| 	inst->alg.setkey = chachapoly_setkey;
 | |
| 	inst->alg.setauthsize = chachapoly_setauthsize;
 | |
| 
 | |
| 	inst->free = chachapoly_free;
 | |
| 
 | |
| 	err = aead_register_instance(tmpl, inst);
 | |
| 	if (err)
 | |
| 		goto out_drop_chacha;
 | |
| 
 | |
| out_put_poly:
 | |
| 	crypto_mod_put(poly);
 | |
| 	return err;
 | |
| 
 | |
| out_drop_chacha:
 | |
| 	crypto_drop_skcipher(&ctx->chacha);
 | |
| err_drop_poly:
 | |
| 	crypto_drop_ahash(&ctx->poly);
 | |
| err_free_inst:
 | |
| 	kfree(inst);
 | |
| 	goto out_put_poly;
 | |
| }
 | |
| 
 | |
| static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
 | |
| {
 | |
| 	return chachapoly_create(tmpl, tb, "rfc7539", 12);
 | |
| }
 | |
| 
 | |
| static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
 | |
| {
 | |
| 	return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
 | |
| }
 | |
| 
 | |
| static struct crypto_template rfc7539_tmpl = {
 | |
| 	.name = "rfc7539",
 | |
| 	.create = rfc7539_create,
 | |
| 	.module = THIS_MODULE,
 | |
| };
 | |
| 
 | |
| static struct crypto_template rfc7539esp_tmpl = {
 | |
| 	.name = "rfc7539esp",
 | |
| 	.create = rfc7539esp_create,
 | |
| 	.module = THIS_MODULE,
 | |
| };
 | |
| 
 | |
| static int __init chacha20poly1305_module_init(void)
 | |
| {
 | |
| 	int err;
 | |
| 
 | |
| 	err = crypto_register_template(&rfc7539_tmpl);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| 	err = crypto_register_template(&rfc7539esp_tmpl);
 | |
| 	if (err)
 | |
| 		crypto_unregister_template(&rfc7539_tmpl);
 | |
| 
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| static void __exit chacha20poly1305_module_exit(void)
 | |
| {
 | |
| 	crypto_unregister_template(&rfc7539esp_tmpl);
 | |
| 	crypto_unregister_template(&rfc7539_tmpl);
 | |
| }
 | |
| 
 | |
| module_init(chacha20poly1305_module_init);
 | |
| module_exit(chacha20poly1305_module_exit);
 | |
| 
 | |
| MODULE_LICENSE("GPL");
 | |
| MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
 | |
| MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
 | |
| MODULE_ALIAS_CRYPTO("rfc7539");
 | |
| MODULE_ALIAS_CRYPTO("rfc7539esp");
 |