Release 4.11 crypto/chacha20poly1305.c

Directory: crypto
/*
 * 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);
}

Contributors
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Martin Willi 57 100.00% 1 100.00%
Total 57 100.00% 1 100.00%



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);
}

Contributors
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Martin Willi 99 100.00% 1 100.00%
Total 99 100.00% 1 100.00%



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;
}

Contributors
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Martin Willi 75 94.94% 1 50.00%
Herbert Xu 4 5.06% 1 50.00%
Total 79 100.00% 2 100.00%



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;
}

Contributors
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Martin Willi 48 92.31% 1 50.00%
Herbert Xu 4 7.69% 1 50.00%
Total 52 100.00% 2 100.00%



static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_verify_tag);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 128 57.92% 1 25.00%
Herbert Xu 80 36.20% 2 50.00%
Jason A. Donenfeld 13 5.88% 1 25.00%
Total 221 100.00% 4 100.00%



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);
}

Contributors
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Martin Willi 44 100.00% 1 100.00%
Total 44 100.00% 1 100.00%



static void poly_tail_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_tail_continue);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
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Martin Willi 204 94.44% 1 50.00%
Herbert Xu 12 5.56% 1 50.00%
Total 216 100.00% 2 100.00%



static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_tail);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
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Martin Willi 180 100.00% 1 100.00%
Total 180 100.00% 1 100.00%



static void poly_cipher_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_cipherpad);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 143 85.63% 1 50.00%
Herbert Xu 24 14.37% 1 50.00%
Total 167 100.00% 2 100.00%



static void poly_adpad_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_cipher);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 178 99.44% 1 50.00%
Herbert Xu 1 0.56% 1 50.00%
Total 179 100.00% 2 100.00%



static void poly_ad_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_adpad);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 117 98.32% 1 50.00%
Herbert Xu 2 1.68% 1 50.00%
Total 119 100.00% 2 100.00%



static void poly_setkey_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_ad);
}

Contributors
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Martin Willi 25 100.00% 2 100.00%
Total 25 100.00% 2 100.00%



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);
}

Contributors
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Martin Willi 149 100.00% 2 100.00%
Total 149 100.00% 2 100.00%



static void poly_init_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_setkey);
}

Contributors
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Martin Willi 25 100.00% 2 100.00%
Total 25 100.00% 2 100.00%



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);
}

Contributors
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Martin Willi 101 100.00% 2 100.00%
Total 101 100.00% 2 100.00%



static void poly_genkey_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_init);
}

Contributors
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Martin Willi 25 100.00% 2 100.00%
Total 25 100.00% 2 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 169 76.47% 2 50.00%
Herbert Xu 52 23.53% 2 50.00%
Total 221 100.00% 4 100.00%



static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
{
	async_done_continue(areq->data, err, poly_genkey);
}

Contributors
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Martin Willi 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 109 49.32% 1 25.00%
Herbert Xu 99 44.80% 2 50.00%
Jason A. Donenfeld 13 5.88% 1 25.00%
Total 221 100.00% 4 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 36 100.00% 2 100.00%
Total 36 100.00% 2 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 38 100.00% 2 100.00%
Total 38 100.00% 2 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 117 96.69% 1 50.00%
Herbert Xu 4 3.31% 1 50.00%
Total 121 100.00% 2 100.00%



static int chachapoly_setauthsize(struct crypto_aead *tfm,
				  unsigned int authsize)
{
	if (authsize != POLY1305_DIGEST_SIZE)
		return -EINVAL;

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Martin Willi 28 100.00% 1 100.00%
Total 28 100.00% 1 100.00%



static
Person	Tokens	Prop	Commits	CommitProp
Martin Willi	57	100.00%	1	100.00%
Total	57	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.11 crypto/chacha20poly1305.c

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