.. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
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1 | 2 | /* |
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2 | 3 | * lib80211 crypt: host-based CCMP encryption implementation for lib80211 |
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3 | 4 | * |
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4 | 5 | * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi> |
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5 | 6 | * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com> |
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6 | | - * |
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7 | | - * This program is free software; you can redistribute it and/or modify |
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8 | | - * it under the terms of the GNU General Public License version 2 as |
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9 | | - * published by the Free Software Foundation. See README and COPYING for |
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10 | | - * more details. |
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11 | 7 | */ |
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12 | 8 | |
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13 | 9 | #include <linux/kernel.h> |
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.. | .. |
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26 | 22 | #include <linux/ieee80211.h> |
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27 | 23 | |
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28 | 24 | #include <linux/crypto.h> |
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| 25 | +#include <crypto/aead.h> |
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29 | 26 | |
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30 | 27 | #include <net/lib80211.h> |
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31 | 28 | |
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.. | .. |
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52 | 49 | |
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53 | 50 | int key_idx; |
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54 | 51 | |
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55 | | - struct crypto_cipher *tfm; |
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| 52 | + struct crypto_aead *tfm; |
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56 | 53 | |
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57 | 54 | /* scratch buffers for virt_to_page() (crypto API) */ |
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58 | | - u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN], |
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59 | | - tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN]; |
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60 | | - u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN]; |
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| 55 | + u8 tx_aad[2 * AES_BLOCK_LEN]; |
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| 56 | + u8 rx_aad[2 * AES_BLOCK_LEN]; |
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61 | 57 | }; |
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62 | | - |
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63 | | -static inline void lib80211_ccmp_aes_encrypt(struct crypto_cipher *tfm, |
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64 | | - const u8 pt[16], u8 ct[16]) |
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65 | | -{ |
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66 | | - crypto_cipher_encrypt_one(tfm, ct, pt); |
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67 | | -} |
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68 | 58 | |
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69 | 59 | static void *lib80211_ccmp_init(int key_idx) |
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70 | 60 | { |
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.. | .. |
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75 | 65 | goto fail; |
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76 | 66 | priv->key_idx = key_idx; |
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77 | 67 | |
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78 | | - priv->tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); |
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| 68 | + priv->tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC); |
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79 | 69 | if (IS_ERR(priv->tfm)) { |
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80 | 70 | priv->tfm = NULL; |
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81 | 71 | goto fail; |
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.. | .. |
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86 | 76 | fail: |
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87 | 77 | if (priv) { |
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88 | 78 | if (priv->tfm) |
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89 | | - crypto_free_cipher(priv->tfm); |
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| 79 | + crypto_free_aead(priv->tfm); |
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90 | 80 | kfree(priv); |
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91 | 81 | } |
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92 | 82 | |
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.. | .. |
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97 | 87 | { |
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98 | 88 | struct lib80211_ccmp_data *_priv = priv; |
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99 | 89 | if (_priv && _priv->tfm) |
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100 | | - crypto_free_cipher(_priv->tfm); |
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| 90 | + crypto_free_aead(_priv->tfm); |
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101 | 91 | kfree(priv); |
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102 | 92 | } |
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103 | 93 | |
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104 | | -static inline void xor_block(u8 * b, u8 * a, size_t len) |
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105 | | -{ |
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106 | | - int i; |
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107 | | - for (i = 0; i < len; i++) |
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108 | | - b[i] ^= a[i]; |
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109 | | -} |
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110 | | - |
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111 | | -static void ccmp_init_blocks(struct crypto_cipher *tfm, |
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112 | | - struct ieee80211_hdr *hdr, |
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113 | | - u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0) |
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| 94 | +static int ccmp_init_iv_and_aad(const struct ieee80211_hdr *hdr, |
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| 95 | + const u8 *pn, u8 *iv, u8 *aad) |
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114 | 96 | { |
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115 | 97 | u8 *pos, qc = 0; |
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116 | 98 | size_t aad_len; |
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117 | 99 | int a4_included, qc_included; |
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118 | | - u8 aad[2 * AES_BLOCK_LEN]; |
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119 | 100 | |
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120 | 101 | a4_included = ieee80211_has_a4(hdr->frame_control); |
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121 | 102 | qc_included = ieee80211_is_data_qos(hdr->frame_control); |
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.. | .. |
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131 | 112 | aad_len += 2; |
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132 | 113 | } |
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133 | 114 | |
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134 | | - /* CCM Initial Block: |
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135 | | - * Flag (Include authentication header, M=3 (8-octet MIC), |
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136 | | - * L=1 (2-octet Dlen)) |
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137 | | - * Nonce: 0x00 | A2 | PN |
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138 | | - * Dlen */ |
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139 | | - b0[0] = 0x59; |
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140 | | - b0[1] = qc; |
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141 | | - memcpy(b0 + 2, hdr->addr2, ETH_ALEN); |
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142 | | - memcpy(b0 + 8, pn, CCMP_PN_LEN); |
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143 | | - b0[14] = (dlen >> 8) & 0xff; |
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144 | | - b0[15] = dlen & 0xff; |
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| 115 | + /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC |
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| 116 | + * mode authentication are not allowed to collide, yet both are derived |
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| 117 | + * from the same vector. We only set L := 1 here to indicate that the |
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| 118 | + * data size can be represented in (L+1) bytes. The CCM layer will take |
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| 119 | + * care of storing the data length in the top (L+1) bytes and setting |
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| 120 | + * and clearing the other bits as is required to derive the two IVs. |
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| 121 | + */ |
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| 122 | + iv[0] = 0x1; |
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| 123 | + |
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| 124 | + /* Nonce: QC | A2 | PN */ |
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| 125 | + iv[1] = qc; |
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| 126 | + memcpy(iv + 2, hdr->addr2, ETH_ALEN); |
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| 127 | + memcpy(iv + 8, pn, CCMP_PN_LEN); |
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145 | 128 | |
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146 | 129 | /* AAD: |
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147 | 130 | * FC with bits 4..6 and 11..13 masked to zero; 14 is always one |
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.. | .. |
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151 | 134 | * QC (if present) |
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152 | 135 | */ |
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153 | 136 | pos = (u8 *) hdr; |
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154 | | - aad[0] = 0; /* aad_len >> 8 */ |
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155 | | - aad[1] = aad_len & 0xff; |
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156 | | - aad[2] = pos[0] & 0x8f; |
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157 | | - aad[3] = pos[1] & 0xc7; |
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158 | | - memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN); |
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| 137 | + aad[0] = pos[0] & 0x8f; |
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| 138 | + aad[1] = pos[1] & 0xc7; |
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| 139 | + memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN); |
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159 | 140 | pos = (u8 *) & hdr->seq_ctrl; |
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160 | | - aad[22] = pos[0] & 0x0f; |
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161 | | - aad[23] = 0; /* all bits masked */ |
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162 | | - memset(aad + 24, 0, 8); |
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| 141 | + aad[20] = pos[0] & 0x0f; |
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| 142 | + aad[21] = 0; /* all bits masked */ |
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| 143 | + memset(aad + 22, 0, 8); |
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163 | 144 | if (a4_included) |
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164 | | - memcpy(aad + 24, hdr->addr4, ETH_ALEN); |
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| 145 | + memcpy(aad + 22, hdr->addr4, ETH_ALEN); |
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165 | 146 | if (qc_included) { |
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166 | | - aad[a4_included ? 30 : 24] = qc; |
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| 147 | + aad[a4_included ? 28 : 22] = qc; |
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167 | 148 | /* rest of QC masked */ |
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168 | 149 | } |
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169 | | - |
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170 | | - /* Start with the first block and AAD */ |
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171 | | - lib80211_ccmp_aes_encrypt(tfm, b0, auth); |
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172 | | - xor_block(auth, aad, AES_BLOCK_LEN); |
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173 | | - lib80211_ccmp_aes_encrypt(tfm, auth, auth); |
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174 | | - xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); |
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175 | | - lib80211_ccmp_aes_encrypt(tfm, auth, auth); |
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176 | | - b0[0] &= 0x07; |
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177 | | - b0[14] = b0[15] = 0; |
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178 | | - lib80211_ccmp_aes_encrypt(tfm, b0, s0); |
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| 150 | + return aad_len; |
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179 | 151 | } |
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180 | 152 | |
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181 | 153 | static int lib80211_ccmp_hdr(struct sk_buff *skb, int hdr_len, |
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.. | .. |
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218 | 190 | static int lib80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv) |
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219 | 191 | { |
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220 | 192 | struct lib80211_ccmp_data *key = priv; |
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221 | | - int data_len, i, blocks, last, len; |
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222 | | - u8 *pos, *mic; |
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223 | 193 | struct ieee80211_hdr *hdr; |
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224 | | - u8 *b0 = key->tx_b0; |
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225 | | - u8 *b = key->tx_b; |
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226 | | - u8 *e = key->tx_e; |
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227 | | - u8 *s0 = key->tx_s0; |
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| 194 | + struct aead_request *req; |
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| 195 | + struct scatterlist sg[2]; |
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| 196 | + u8 *aad = key->tx_aad; |
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| 197 | + u8 iv[AES_BLOCK_LEN]; |
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| 198 | + int len, data_len, aad_len; |
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| 199 | + int ret; |
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228 | 200 | |
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229 | 201 | if (skb_tailroom(skb) < CCMP_MIC_LEN || skb->len < hdr_len) |
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230 | 202 | return -1; |
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.. | .. |
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234 | 206 | if (len < 0) |
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235 | 207 | return -1; |
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236 | 208 | |
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237 | | - pos = skb->data + hdr_len + CCMP_HDR_LEN; |
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| 209 | + req = aead_request_alloc(key->tfm, GFP_ATOMIC); |
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| 210 | + if (!req) |
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| 211 | + return -ENOMEM; |
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| 212 | + |
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238 | 213 | hdr = (struct ieee80211_hdr *)skb->data; |
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239 | | - ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0); |
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| 214 | + aad_len = ccmp_init_iv_and_aad(hdr, key->tx_pn, iv, aad); |
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240 | 215 | |
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241 | | - blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN); |
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242 | | - last = data_len % AES_BLOCK_LEN; |
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| 216 | + skb_put(skb, CCMP_MIC_LEN); |
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243 | 217 | |
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244 | | - for (i = 1; i <= blocks; i++) { |
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245 | | - len = (i == blocks && last) ? last : AES_BLOCK_LEN; |
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246 | | - /* Authentication */ |
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247 | | - xor_block(b, pos, len); |
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248 | | - lib80211_ccmp_aes_encrypt(key->tfm, b, b); |
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249 | | - /* Encryption, with counter */ |
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250 | | - b0[14] = (i >> 8) & 0xff; |
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251 | | - b0[15] = i & 0xff; |
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252 | | - lib80211_ccmp_aes_encrypt(key->tfm, b0, e); |
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253 | | - xor_block(pos, e, len); |
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254 | | - pos += len; |
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255 | | - } |
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| 218 | + sg_init_table(sg, 2); |
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| 219 | + sg_set_buf(&sg[0], aad, aad_len); |
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| 220 | + sg_set_buf(&sg[1], skb->data + hdr_len + CCMP_HDR_LEN, |
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| 221 | + data_len + CCMP_MIC_LEN); |
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256 | 222 | |
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257 | | - mic = skb_put(skb, CCMP_MIC_LEN); |
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258 | | - for (i = 0; i < CCMP_MIC_LEN; i++) |
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259 | | - mic[i] = b[i] ^ s0[i]; |
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| 223 | + aead_request_set_callback(req, 0, NULL, NULL); |
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| 224 | + aead_request_set_ad(req, aad_len); |
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| 225 | + aead_request_set_crypt(req, sg, sg, data_len, iv); |
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260 | 226 | |
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261 | | - return 0; |
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| 227 | + ret = crypto_aead_encrypt(req); |
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| 228 | + aead_request_free(req); |
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| 229 | + |
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| 230 | + return ret; |
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262 | 231 | } |
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263 | 232 | |
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264 | 233 | /* |
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.. | .. |
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287 | 256 | struct lib80211_ccmp_data *key = priv; |
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288 | 257 | u8 keyidx, *pos; |
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289 | 258 | struct ieee80211_hdr *hdr; |
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290 | | - u8 *b0 = key->rx_b0; |
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291 | | - u8 *b = key->rx_b; |
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292 | | - u8 *a = key->rx_a; |
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| 259 | + struct aead_request *req; |
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| 260 | + struct scatterlist sg[2]; |
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| 261 | + u8 *aad = key->rx_aad; |
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| 262 | + u8 iv[AES_BLOCK_LEN]; |
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293 | 263 | u8 pn[6]; |
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294 | | - int i, blocks, last, len; |
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295 | | - size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN; |
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296 | | - u8 *mic = skb->data + skb->len - CCMP_MIC_LEN; |
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| 264 | + int aad_len, ret; |
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| 265 | + size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN; |
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297 | 266 | |
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298 | 267 | if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) { |
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299 | 268 | key->dot11RSNAStatsCCMPFormatErrors++; |
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.. | .. |
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341 | 310 | return -4; |
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342 | 311 | } |
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343 | 312 | |
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344 | | - ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b); |
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345 | | - xor_block(mic, b, CCMP_MIC_LEN); |
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| 313 | + req = aead_request_alloc(key->tfm, GFP_ATOMIC); |
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| 314 | + if (!req) |
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| 315 | + return -ENOMEM; |
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346 | 316 | |
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347 | | - blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN); |
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348 | | - last = data_len % AES_BLOCK_LEN; |
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| 317 | + aad_len = ccmp_init_iv_and_aad(hdr, pn, iv, aad); |
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349 | 318 | |
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350 | | - for (i = 1; i <= blocks; i++) { |
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351 | | - len = (i == blocks && last) ? last : AES_BLOCK_LEN; |
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352 | | - /* Decrypt, with counter */ |
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353 | | - b0[14] = (i >> 8) & 0xff; |
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354 | | - b0[15] = i & 0xff; |
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355 | | - lib80211_ccmp_aes_encrypt(key->tfm, b0, b); |
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356 | | - xor_block(pos, b, len); |
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357 | | - /* Authentication */ |
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358 | | - xor_block(a, pos, len); |
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359 | | - lib80211_ccmp_aes_encrypt(key->tfm, a, a); |
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360 | | - pos += len; |
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361 | | - } |
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| 319 | + sg_init_table(sg, 2); |
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| 320 | + sg_set_buf(&sg[0], aad, aad_len); |
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| 321 | + sg_set_buf(&sg[1], pos, data_len); |
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362 | 322 | |
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363 | | - if (memcmp(mic, a, CCMP_MIC_LEN) != 0) { |
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364 | | - net_dbg_ratelimited("CCMP: decrypt failed: STA=%pM\n", |
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365 | | - hdr->addr2); |
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| 323 | + aead_request_set_callback(req, 0, NULL, NULL); |
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| 324 | + aead_request_set_ad(req, aad_len); |
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| 325 | + aead_request_set_crypt(req, sg, sg, data_len, iv); |
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| 326 | + |
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| 327 | + ret = crypto_aead_decrypt(req); |
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| 328 | + aead_request_free(req); |
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| 329 | + |
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| 330 | + if (ret) { |
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| 331 | + net_dbg_ratelimited("CCMP: decrypt failed: STA=%pM (%d)\n", |
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| 332 | + hdr->addr2, ret); |
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366 | 333 | key->dot11RSNAStatsCCMPDecryptErrors++; |
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367 | 334 | return -5; |
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368 | 335 | } |
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.. | .. |
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381 | 348 | { |
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382 | 349 | struct lib80211_ccmp_data *data = priv; |
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383 | 350 | int keyidx; |
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384 | | - struct crypto_cipher *tfm = data->tfm; |
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| 351 | + struct crypto_aead *tfm = data->tfm; |
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385 | 352 | |
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386 | 353 | keyidx = data->key_idx; |
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387 | 354 | memset(data, 0, sizeof(*data)); |
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.. | .. |
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398 | 365 | data->rx_pn[4] = seq[1]; |
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399 | 366 | data->rx_pn[5] = seq[0]; |
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400 | 367 | } |
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401 | | - crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN); |
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| 368 | + if (crypto_aead_setauthsize(data->tfm, CCMP_MIC_LEN) || |
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| 369 | + crypto_aead_setkey(data->tfm, data->key, CCMP_TK_LEN)) |
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| 370 | + return -1; |
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402 | 371 | } else if (len == 0) |
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403 | 372 | data->key_set = 0; |
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404 | 373 | else |
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