1765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen/* 2765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen * AES-128-CMAC with TLen 16 for IEEE 802.11w BIP 3765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen * Copyright 2008, Jouni Malinen <j@w1.fi> 4765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen * 5765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen * This program is free software; you can redistribute it and/or modify 6765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen * it under the terms of the GNU General Public License version 2 as 7765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen * published by the Free Software Foundation. 8765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen */ 9765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 10765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include <linux/kernel.h> 11765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include <linux/types.h> 12765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include <linux/crypto.h> 134afebd6364903d9616073b1fb71a75291e55dfecEmmanuel Grumbach#include <linux/export.h> 14765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include <linux/err.h> 150cd20a278e1ef9da9f6a987942794c9d65af8c4dJohannes Berg#include <crypto/aes.h> 16765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 17765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include <net/mac80211.h> 18765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include "key.h" 19765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#include "aes_cmac.h" 20765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 21765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#define AES_CMAC_KEY_LEN 16 22765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */ 23765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen#define AAD_LEN 20 24765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 25765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 26765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinenstatic void gf_mulx(u8 *pad) 27765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen{ 28765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen int i, carry; 29765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 30765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen carry = pad[0] & 0x80; 31765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen for (i = 0; i < AES_BLOCK_SIZE - 1; i++) 32765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7); 33765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pad[AES_BLOCK_SIZE - 1] <<= 1; 34765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen if (carry) 35765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pad[AES_BLOCK_SIZE - 1] ^= 0x87; 36765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen} 37765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 38765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 3975396ae6d433b49482e377e6f8dbf1f42ad53f3aJohannes Bergstatic void aes_128_cmac_vector(struct crypto_cipher *tfm, size_t num_elem, 40765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen const u8 *addr[], const size_t *len, u8 *mac) 41765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen{ 42d348f69f59af769c405c2f43a2d326d7123ef75aJohannes Berg u8 cbc[AES_BLOCK_SIZE], pad[AES_BLOCK_SIZE]; 43765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen const u8 *pos, *end; 44765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen size_t i, e, left, total_len; 45765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 46765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen memset(cbc, 0, AES_BLOCK_SIZE); 47765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 48765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen total_len = 0; 49765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen for (e = 0; e < num_elem; e++) 50765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen total_len += len[e]; 51765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen left = total_len; 52765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 53765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen e = 0; 54765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pos = addr[0]; 55765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen end = pos + len[0]; 56765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 57765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen while (left >= AES_BLOCK_SIZE) { 58765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen for (i = 0; i < AES_BLOCK_SIZE; i++) { 59765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen cbc[i] ^= *pos++; 60765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen if (pos >= end) { 61765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen e++; 62765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pos = addr[e]; 63765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen end = pos + len[e]; 64765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen } 65765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen } 66765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen if (left > AES_BLOCK_SIZE) 67765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen crypto_cipher_encrypt_one(tfm, cbc, cbc); 68765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen left -= AES_BLOCK_SIZE; 69765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen } 70765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 71765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen memset(pad, 0, AES_BLOCK_SIZE); 72765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen crypto_cipher_encrypt_one(tfm, pad, pad); 73765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen gf_mulx(pad); 74765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 75765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen if (left || total_len == 0) { 76765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen for (i = 0; i < left; i++) { 77765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen cbc[i] ^= *pos++; 78765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen if (pos >= end) { 79765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen e++; 80765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pos = addr[e]; 81765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen end = pos + len[e]; 82765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen } 83765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen } 84765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen cbc[left] ^= 0x80; 85765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen gf_mulx(pad); 86765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen } 87765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 88765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen for (i = 0; i < AES_BLOCK_SIZE; i++) 89765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen pad[i] ^= cbc[i]; 90765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen crypto_cipher_encrypt_one(tfm, pad, pad); 91765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen memcpy(mac, pad, CMAC_TLEN); 92765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen} 93765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 94765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 9575396ae6d433b49482e377e6f8dbf1f42ad53f3aJohannes Bergvoid ieee80211_aes_cmac(struct crypto_cipher *tfm, const u8 *aad, 96765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen const u8 *data, size_t data_len, u8 *mic) 97765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen{ 98765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen const u8 *addr[3]; 99765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen size_t len[3]; 100765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen u8 zero[CMAC_TLEN]; 101765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 102765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen memset(zero, 0, CMAC_TLEN); 103765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen addr[0] = aad; 104765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen len[0] = AAD_LEN; 105765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen addr[1] = data; 106765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen len[1] = data_len - CMAC_TLEN; 107765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen addr[2] = zero; 108765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen len[2] = CMAC_TLEN; 109765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 11075396ae6d433b49482e377e6f8dbf1f42ad53f3aJohannes Berg aes_128_cmac_vector(tfm, 3, addr, len, mic); 111765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen} 112765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 113765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 114f359d3fe832e49eeec2232b2af5a9e3aee6b4862Weilong Chenstruct crypto_cipher *ieee80211_aes_cmac_key_setup(const u8 key[]) 115765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen{ 116765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen struct crypto_cipher *tfm; 117765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 118765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); 1191ac62ba7c985109868a18d959986425148481f47Ben Hutchings if (!IS_ERR(tfm)) 1201ac62ba7c985109868a18d959986425148481f47Ben Hutchings crypto_cipher_setkey(tfm, key, AES_CMAC_KEY_LEN); 121765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 122765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen return tfm; 123765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen} 124765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 125765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen 126765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinenvoid ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm) 127765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen{ 128ffa56e540c3949c4560dcce45eca247819e183c1Jesper Juhl crypto_free_cipher(tfm); 129765cb46a3fc856245ea68a7c961ac87c77e4ae2dJouni Malinen} 1305d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss 1315d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Kraussvoid ieee80211_aes_cmac_calculate_k1_k2(struct ieee80211_key_conf *keyconf, 1325d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss u8 *k1, u8 *k2) 1335d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss{ 1345d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss u8 l[AES_BLOCK_SIZE] = {}; 1355d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss struct ieee80211_key *key = 1365d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss container_of(keyconf, struct ieee80211_key, conf); 1375d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss 1385d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss crypto_cipher_encrypt_one(key->u.aes_cmac.tfm, l, l); 1395d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss 1405d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss memcpy(k1, l, AES_BLOCK_SIZE); 1415d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss gf_mulx(k1); 1425d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss 1435d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss memcpy(k2, k1, AES_BLOCK_SIZE); 1445d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss gf_mulx(k2); 1455d0d04e477c44993f995f35b728ce9dd57a4615eAssaf Krauss} 1465d0d04e477c44993f995f35b728ce9dd57a4615eAssaf KraussEXPORT_SYMBOL(ieee80211_aes_cmac_calculate_k1_k2); 147