1/* 2 * Copyright 2014-2015, Qualcomm Atheros, Inc. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 9#include <linux/kernel.h> 10#include <linux/types.h> 11#include <linux/crypto.h> 12#include <linux/err.h> 13#include <crypto/aes.h> 14 15#include <net/mac80211.h> 16#include "key.h" 17#include "aes_gcm.h" 18 19void ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad, 20 u8 *data, size_t data_len, u8 *mic) 21{ 22 struct scatterlist assoc, pt, ct[2]; 23 24 char aead_req_data[sizeof(struct aead_request) + 25 crypto_aead_reqsize(tfm)] 26 __aligned(__alignof__(struct aead_request)); 27 struct aead_request *aead_req = (void *)aead_req_data; 28 29 memset(aead_req, 0, sizeof(aead_req_data)); 30 31 sg_init_one(&pt, data, data_len); 32 sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad)); 33 sg_init_table(ct, 2); 34 sg_set_buf(&ct[0], data, data_len); 35 sg_set_buf(&ct[1], mic, IEEE80211_GCMP_MIC_LEN); 36 37 aead_request_set_tfm(aead_req, tfm); 38 aead_request_set_assoc(aead_req, &assoc, assoc.length); 39 aead_request_set_crypt(aead_req, &pt, ct, data_len, j_0); 40 41 crypto_aead_encrypt(aead_req); 42} 43 44int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad, 45 u8 *data, size_t data_len, u8 *mic) 46{ 47 struct scatterlist assoc, pt, ct[2]; 48 char aead_req_data[sizeof(struct aead_request) + 49 crypto_aead_reqsize(tfm)] 50 __aligned(__alignof__(struct aead_request)); 51 struct aead_request *aead_req = (void *)aead_req_data; 52 53 if (data_len == 0) 54 return -EINVAL; 55 56 memset(aead_req, 0, sizeof(aead_req_data)); 57 58 sg_init_one(&pt, data, data_len); 59 sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad)); 60 sg_init_table(ct, 2); 61 sg_set_buf(&ct[0], data, data_len); 62 sg_set_buf(&ct[1], mic, IEEE80211_GCMP_MIC_LEN); 63 64 aead_request_set_tfm(aead_req, tfm); 65 aead_request_set_assoc(aead_req, &assoc, assoc.length); 66 aead_request_set_crypt(aead_req, ct, &pt, 67 data_len + IEEE80211_GCMP_MIC_LEN, j_0); 68 69 return crypto_aead_decrypt(aead_req); 70} 71 72struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(const u8 key[], 73 size_t key_len) 74{ 75 struct crypto_aead *tfm; 76 int err; 77 78 tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC); 79 if (IS_ERR(tfm)) 80 return tfm; 81 82 err = crypto_aead_setkey(tfm, key, key_len); 83 if (err) 84 goto free_aead; 85 err = crypto_aead_setauthsize(tfm, IEEE80211_GCMP_MIC_LEN); 86 if (err) 87 goto free_aead; 88 89 return tfm; 90 91free_aead: 92 crypto_free_aead(tfm); 93 return ERR_PTR(err); 94} 95 96void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm) 97{ 98 crypto_free_aead(tfm); 99} 100