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| author | Dmitry Shmidt <dimitrysh@google.com> | 2012-09-11 15:06:38 -0700 |
|---|---|---|
| committer | Dmitry Shmidt <dimitrysh@google.com> | 2012-09-13 16:20:52 -0700 |
| commit | 9bce59c7fef20e34a05f04d1e33a4076083dca0c (patch) | |
| tree | 900c0d9f8897097769b1d4fd4e642d22e832cb79 /src/crypto/aes-gcm.c | |
| parent | 2b380488c6b5d21e54e98397c7a8d6a9f16dd8b5 (diff) | |
| download | android_external_wpa_supplicant_8-9bce59c7fef20e34a05f04d1e33a4076083dca0c.tar.gz android_external_wpa_supplicant_8-9bce59c7fef20e34a05f04d1e33a4076083dca0c.tar.bz2 android_external_wpa_supplicant_8-9bce59c7fef20e34a05f04d1e33a4076083dca0c.zip | |
wpa_supplicant: Update to 10-Sep-2012 TOT
commit 762b99db7a76803d1ad274e87caa6fe870d47441
Author: Jouni Malinen <j@w1.fi>
Date: Mon Sep 10 12:33:29 2012 +0200
Fix last_scan_res update existing BSS entry is update
Change-Id: I03f933bf6d7f7e36b0f8ac410fbc37990f127c18
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Diffstat (limited to 'src/crypto/aes-gcm.c')
| -rw-r--r-- | src/crypto/aes-gcm.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/src/crypto/aes-gcm.c b/src/crypto/aes-gcm.c new file mode 100644 index 00000000..3d91c71d --- /dev/null +++ b/src/crypto/aes-gcm.c @@ -0,0 +1,327 @@ +/* + * Galois/Counter Mode (GCM) and GMAC with AES + * + * Copyright (c) 2012, Jouni Malinen <j@w1.fi> + * + * This software may be distributed under the terms of the BSD license. + * See README for more details. + */ + +#include "includes.h" + +#include "common.h" +#include "aes.h" +#include "aes_wrap.h" + +static void inc32(u8 *block) +{ + u32 val; + val = WPA_GET_BE32(block + AES_BLOCK_SIZE - 4); + val++; + WPA_PUT_BE32(block + AES_BLOCK_SIZE - 4, val); +} + + +static void xor_block(u8 *dst, const u8 *src) +{ + u32 *d = (u32 *) dst; + u32 *s = (u32 *) src; + *d++ ^= *s++; + *d++ ^= *s++; + *d++ ^= *s++; + *d++ ^= *s++; +} + + +static void shift_right_block(u8 *v) +{ + u32 val; + + val = WPA_GET_BE32(v + 12); + val >>= 1; + if (v[11] & 0x01) + val |= 0x80000000; + WPA_PUT_BE32(v + 12, val); + + val = WPA_GET_BE32(v + 8); + val >>= 1; + if (v[7] & 0x01) + val |= 0x80000000; + WPA_PUT_BE32(v + 8, val); + + val = WPA_GET_BE32(v + 4); + val >>= 1; + if (v[3] & 0x01) + val |= 0x80000000; + WPA_PUT_BE32(v + 4, val); + + val = WPA_GET_BE32(v); + val >>= 1; + WPA_PUT_BE32(v, val); +} + + +/* Multiplication in GF(2^128) */ +static void gf_mult(const u8 *x, const u8 *y, u8 *z) +{ + u8 v[16]; + int i, j; + + os_memset(z, 0, 16); /* Z_0 = 0^128 */ + os_memcpy(v, y, 16); /* V_0 = Y */ + + for (i = 0; i < 16; i++) { + for (j = 0; j < 8; j++) { + if (x[i] & BIT(7 - j)) { + /* Z_(i + 1) = Z_i XOR V_i */ + xor_block(z, v); + } else { + /* Z_(i + 1) = Z_i */ + } + + if (v[15] & 0x01) { + /* V_(i + 1) = (V_i >> 1) XOR R */ + shift_right_block(v); + /* R = 11100001 || 0^120 */ + v[0] ^= 0xe1; + } else { + /* V_(i + 1) = V_i >> 1 */ + shift_right_block(v); + } + } + } +} + + +static void ghash_start(u8 *y) +{ + /* Y_0 = 0^128 */ + os_memset(y, 0, 16); +} + + +static void ghash(const u8 *h, const u8 *x, size_t xlen, u8 *y) +{ + size_t m, i; + const u8 *xpos = x; + u8 tmp[16]; + + m = xlen / 16; + + for (i = 0; i < m; i++) { + /* Y_i = (Y^(i-1) XOR X_i) dot H */ + xor_block(y, xpos); + xpos += 16; + + /* dot operation: + * multiplication operation for binary Galois (finite) field of + * 2^128 elements */ + gf_mult(y, h, tmp); + os_memcpy(y, tmp, 16); + } + + if (x + xlen > xpos) { + /* Add zero padded last block */ + size_t last = x + xlen - xpos; + os_memcpy(tmp, xpos, last); + os_memset(tmp + last, 0, sizeof(tmp) - last); + + /* Y_i = (Y^(i-1) XOR X_i) dot H */ + xor_block(y, tmp); + + /* dot operation: + * multiplication operation for binary Galois (finite) field of + * 2^128 elements */ + gf_mult(y, h, tmp); + os_memcpy(y, tmp, 16); + } + + /* Return Y_m */ +} + + +static void aes_gctr(void *aes, const u8 *icb, const u8 *x, size_t xlen, u8 *y) +{ + size_t i, n, last; + u8 cb[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE]; + const u8 *xpos = x; + u8 *ypos = y; + + if (xlen == 0) + return; + + n = xlen / 16; + + os_memcpy(cb, icb, AES_BLOCK_SIZE); + /* Full blocks */ + for (i = 0; i < n; i++) { + aes_encrypt(aes, cb, ypos); + xor_block(ypos, xpos); + xpos += AES_BLOCK_SIZE; + ypos += AES_BLOCK_SIZE; + inc32(cb); + } + + last = x + xlen - xpos; + if (last) { + /* Last, partial block */ + aes_encrypt(aes, cb, tmp); + for (i = 0; i < last; i++) + *ypos++ = *xpos++ ^ tmp[i]; + } +} + + +static void * aes_gcm_init_hash_subkey(const u8 *key, size_t key_len, u8 *H) +{ + void *aes; + + aes = aes_encrypt_init(key, key_len); + if (aes == NULL) + return NULL; + + /* Generate hash subkey H = AES_K(0^128) */ + os_memset(H, 0, AES_BLOCK_SIZE); + aes_encrypt(aes, H, H); + wpa_hexdump_key(MSG_EXCESSIVE, "Hash subkey H for GHASH", + H, AES_BLOCK_SIZE); + return aes; +} + + +static void aes_gcm_prepare_j0(const u8 *iv, size_t iv_len, const u8 *H, u8 *J0) +{ + u8 len_buf[16]; + + if (iv_len == 12) { + /* Prepare block J_0 = IV || 0^31 || 1 [len(IV) = 96] */ + os_memcpy(J0, iv, iv_len); + os_memset(J0 + iv_len, 0, AES_BLOCK_SIZE - iv_len); + J0[AES_BLOCK_SIZE - 1] = 0x01; + } else { + /* + * s = 128 * ceil(len(IV)/128) - len(IV) + * J_0 = GHASH_H(IV || 0^(s+64) || [len(IV)]_64) + */ + ghash_start(J0); + ghash(H, iv, iv_len, J0); + WPA_PUT_BE64(len_buf, 0); + WPA_PUT_BE64(len_buf + 8, iv_len * 8); + ghash(H, len_buf, sizeof(len_buf), J0); + } +} + + +static void aes_gcm_gctr(void *aes, const u8 *J0, const u8 *in, size_t len, + u8 *out) +{ + u8 J0inc[AES_BLOCK_SIZE]; + + if (len == 0) + return; + + os_memcpy(J0inc, J0, AES_BLOCK_SIZE); + inc32(J0inc); + aes_gctr(aes, J0inc, in, len, out); +} + + +static void aes_gcm_ghash(const u8 *H, const u8 *aad, size_t aad_len, + const u8 *crypt, size_t crypt_len, u8 *S) +{ + u8 len_buf[16]; + + /* + * u = 128 * ceil[len(C)/128] - len(C) + * v = 128 * ceil[len(A)/128] - len(A) + * S = GHASH_H(A || 0^v || C || 0^u || [len(A)]64 || [len(C)]64) + * (i.e., zero padded to block size A || C and lengths of each in bits) + */ + ghash_start(S); + ghash(H, aad, aad_len, S); + ghash(H, crypt, crypt_len, S); + WPA_PUT_BE64(len_buf, aad_len * 8); + WPA_PUT_BE64(len_buf + 8, crypt_len * 8); + ghash(H, len_buf, sizeof(len_buf), S); + + wpa_hexdump_key(MSG_EXCESSIVE, "S = GHASH_H(...)", S, 16); +} + + +/** + * aes_gcm_ae - GCM-AE_K(IV, P, A) + */ +int aes_gcm_ae(const u8 *key, size_t key_len, const u8 *iv, size_t iv_len, + const u8 *plain, size_t plain_len, + const u8 *aad, size_t aad_len, u8 *crypt, u8 *tag) +{ + u8 H[AES_BLOCK_SIZE]; + u8 J0[AES_BLOCK_SIZE]; + u8 S[16]; + void *aes; + + aes = aes_gcm_init_hash_subkey(key, key_len, H); + if (aes == NULL) + return -1; + + aes_gcm_prepare_j0(iv, iv_len, H, J0); + + /* C = GCTR_K(inc_32(J_0), P) */ + aes_gcm_gctr(aes, J0, plain, plain_len, crypt); + + aes_gcm_ghash(H, aad, aad_len, crypt, plain_len, S); + + /* T = MSB_t(GCTR_K(J_0, S)) */ + aes_gctr(aes, J0, S, sizeof(S), tag); + + /* Return (C, T) */ + + aes_encrypt_deinit(aes); + + return 0; +} + + +/** + * aes_gcm_ad - GCM-AD_K(IV, C, A, T) + */ +int aes_gcm_ad(const u8 *key, size_t key_len, const u8 *iv, size_t iv_len, + const u8 *crypt, size_t crypt_len, + const u8 *aad, size_t aad_len, const u8 *tag, u8 *plain) +{ + u8 H[AES_BLOCK_SIZE]; + u8 J0[AES_BLOCK_SIZE]; + u8 S[16], T[16]; + void *aes; + + aes = aes_gcm_init_hash_subkey(key, key_len, H); + if (aes == NULL) + return -1; + + aes_gcm_prepare_j0(iv, iv_len, H, J0); + + /* P = GCTR_K(inc_32(J_0), C) */ + aes_gcm_gctr(aes, J0, crypt, crypt_len, plain); + + aes_gcm_ghash(H, aad, aad_len, crypt, crypt_len, S); + + /* T' = MSB_t(GCTR_K(J_0, S)) */ + aes_gctr(aes, J0, S, sizeof(S), T); + + aes_encrypt_deinit(aes); + + if (os_memcmp(tag, T, 16) != 0) { + wpa_printf(MSG_EXCESSIVE, "GCM: Tag mismatch"); + return -1; + } + + return 0; +} + + +int aes_gmac(const u8 *key, size_t key_len, const u8 *iv, size_t iv_len, + const u8 *aad, size_t aad_len, u8 *tag) +{ + return aes_gcm_ae(key, key_len, iv, iv_len, NULL, 0, aad, aad_len, NULL, + tag); +} |
