1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256 4 * Copyright 2015, Qualcomm Atheros, Inc. 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/types.h> 9 #include <linux/err.h> 10 #include <crypto/aead.h> 11 #include <crypto/aes.h> 12 13 #include <net/mac80211.h> 14 #include "key.h" 15 #include "aes_gmac.h" 16 17 int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce, 18 const u8 *data, size_t data_len, u8 *mic) 19 { 20 struct scatterlist sg[4]; 21 u8 *zero, *__aad, iv[AES_BLOCK_SIZE]; 22 struct aead_request *aead_req; 23 int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm); 24 25 if (data_len < GMAC_MIC_LEN) 26 return -EINVAL; 27 28 aead_req = kzalloc(reqsize + GMAC_MIC_LEN + GMAC_AAD_LEN, GFP_ATOMIC); 29 if (!aead_req) 30 return -ENOMEM; 31 32 zero = (u8 *)aead_req + reqsize; 33 __aad = zero + GMAC_MIC_LEN; 34 memcpy(__aad, aad, GMAC_AAD_LEN); 35 36 sg_init_table(sg, 4); 37 sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN); 38 sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN); 39 sg_set_buf(&sg[2], zero, GMAC_MIC_LEN); 40 sg_set_buf(&sg[3], mic, GMAC_MIC_LEN); 41 42 memcpy(iv, nonce, GMAC_NONCE_LEN); 43 memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN); 44 iv[AES_BLOCK_SIZE - 1] = 0x01; 45 46 aead_request_set_tfm(aead_req, tfm); 47 aead_request_set_crypt(aead_req, sg, sg, 0, iv); 48 aead_request_set_ad(aead_req, GMAC_AAD_LEN + data_len); 49 50 crypto_aead_encrypt(aead_req); 51 kzfree(aead_req); 52 53 return 0; 54 } 55 56 struct crypto_aead *ieee80211_aes_gmac_key_setup(const u8 key[], 57 size_t key_len) 58 { 59 struct crypto_aead *tfm; 60 int err; 61 62 tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC); 63 if (IS_ERR(tfm)) 64 return tfm; 65 66 err = crypto_aead_setkey(tfm, key, key_len); 67 if (!err) 68 err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN); 69 if (!err) 70 return tfm; 71 72 crypto_free_aead(tfm); 73 return ERR_PTR(err); 74 } 75 76 void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm) 77 { 78 crypto_free_aead(tfm); 79 } 80