1/*
  2 * Copyright 2003-2004, Instant802 Networks, Inc.
  3 * Copyright 2005-2006, Devicescape Software, Inc.
  4 * Copyright 2014-2015, Qualcomm Atheros, Inc.
  5 *
  6 * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License version 2 as
 10 * published by the Free Software Foundation.
 11 */
 12
 13#include <linux/kernel.h>
 14#include <linux/types.h>
 15#include <linux/err.h>
 16#include <linux/scatterlist.h>
 17#include <crypto/aead.h>
 18
 19#include "aead_api.h"
 20
 21int aead_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
 22		 u8 *data, size_t data_len, u8 *mic)
 23{
 24	size_t mic_len = crypto_aead_authsize(tfm);
 25	struct scatterlist sg[3];
 26	struct aead_request *aead_req;
 27	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
 28	u8 *__aad;
 29
 30	aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
 31	if (!aead_req)
 32		return -ENOMEM;
 33
 34	__aad = (u8 *)aead_req + reqsize;
 35	memcpy(__aad, aad, aad_len);
 36
 37	sg_init_table(sg, 3);
 38	sg_set_buf(&sg[0], __aad, aad_len);
 39	sg_set_buf(&sg[1], data, data_len);
 40	sg_set_buf(&sg[2], mic, mic_len);
 41
 42	aead_request_set_tfm(aead_req, tfm);
 43	aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
 44	aead_request_set_ad(aead_req, sg[0].length);
 45
 46	crypto_aead_encrypt(aead_req);
 47	kzfree(aead_req);
 48
 49	return 0;
 50}
 51
 52int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
 53		 u8 *data, size_t data_len, u8 *mic)
 54{
 55	size_t mic_len = crypto_aead_authsize(tfm);
 56	struct scatterlist sg[3];
 57	struct aead_request *aead_req;
 58	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
 59	u8 *__aad;
 60	int err;
 61
 62	if (data_len == 0)
 63		return -EINVAL;
 64
 65	aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
 66	if (!aead_req)
 67		return -ENOMEM;
 68
 69	__aad = (u8 *)aead_req + reqsize;
 70	memcpy(__aad, aad, aad_len);
 71
 72	sg_init_table(sg, 3);
 73	sg_set_buf(&sg[0], __aad, aad_len);
 74	sg_set_buf(&sg[1], data, data_len);
 75	sg_set_buf(&sg[2], mic, mic_len);
 76
 77	aead_request_set_tfm(aead_req, tfm);
 78	aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
 79	aead_request_set_ad(aead_req, sg[0].length);
 80
 81	err = crypto_aead_decrypt(aead_req);
 82	kzfree(aead_req);
 83
 84	return err;
 85}
 86
 87struct crypto_aead *
 88aead_key_setup_encrypt(const char *alg, const u8 key[],
 89		       size_t key_len, size_t mic_len)
 90{
 91	struct crypto_aead *tfm;
 92	int err;
 93
 94	tfm = crypto_alloc_aead(alg, 0, CRYPTO_ALG_ASYNC);
 95	if (IS_ERR(tfm))
 96		return tfm;
 97
 98	err = crypto_aead_setkey(tfm, key, key_len);
 99	if (err)
100		goto free_aead;
101	err = crypto_aead_setauthsize(tfm, mic_len);
102	if (err)
103		goto free_aead;
104
105	return tfm;
106
107free_aead:
108	crypto_free_aead(tfm);
109	return ERR_PTR(err);
110}
111
112void aead_key_free(struct crypto_aead *tfm)
113{
114	crypto_free_aead(tfm);
115}