| Jouni Malinen | 00b9cfa | 2015-01-24 19:52:06 +0200 | [diff] [blame] | 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 | |
| 19 | void 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 | |
| 44 | int 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 | |
| 72 | struct 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 | err = crypto_aead_setauthsize(tfm, IEEE80211_GCMP_MIC_LEN); |
| 85 | if (!err) |
| 86 | return tfm; |
| 87 | |
| 88 | crypto_free_aead(tfm); |
| 89 | return ERR_PTR(err); |
| 90 | } |
| 91 | |
| 92 | void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm) |
| 93 | { |
| 94 | crypto_free_aead(tfm); |
| 95 | } |