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 21 int 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 = tfm->authsize; 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 52 int 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 = tfm->authsize; 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 87 struct crypto_aead * 88 aead_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; 106 107 free_aead: 108 crypto_free_aead(tfm); 109 return ERR_PTR(err); 110 } 111 112 void aead_key_free(struct crypto_aead *tfm) 113 { 114 crypto_free_aead(tfm); 115 } 116