Move AES-GCM implementation into src/crypto
This is a generic AES GCM and GMAC implementation that can be used for other purposes than just implementing GCMP, so it fits better in a separate file in src/crypto. Signed-hostap: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen
parent
be87d3c345
commit
1cd7a5032a
4 changed files with 305 additions and 283 deletions
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@ -19,6 +19,7 @@ LIB_OBJS= \
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aes-ctr.o \
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aes-eax.o \
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aes-encblock.o \
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aes-gcm.o \
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aes-internal.o \
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aes-internal-dec.o \
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aes-internal-enc.o \
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291
src/crypto/aes-gcm.c
Normal file
291
src/crypto/aes-gcm.c
Normal file
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@ -0,0 +1,291 @@
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/*
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* Galois/Counter Mode (GCM) and GMAC with AES-128
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*
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* Copyright (c) 2012, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "aes.h"
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#include "aes_wrap.h"
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static void inc32(u8 *block)
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{
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u32 val;
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val = WPA_GET_BE32(block + AES_BLOCK_SIZE - 4);
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val++;
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WPA_PUT_BE32(block + AES_BLOCK_SIZE - 4, val);
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}
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static void xor_block(u8 *dst, const u8 *src)
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{
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u32 *d = (u32 *) dst;
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u32 *s = (u32 *) src;
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*d++ ^= *s++;
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*d++ ^= *s++;
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*d++ ^= *s++;
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*d++ ^= *s++;
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}
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static void shift_right_block(u8 *v)
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{
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u32 val;
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val = WPA_GET_BE32(v + 12);
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val >>= 1;
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if (v[11] & 0x01)
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val |= 0x80000000;
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WPA_PUT_BE32(v + 12, val);
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val = WPA_GET_BE32(v + 8);
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val >>= 1;
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if (v[7] & 0x01)
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val |= 0x80000000;
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WPA_PUT_BE32(v + 8, val);
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val = WPA_GET_BE32(v + 4);
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val >>= 1;
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if (v[3] & 0x01)
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val |= 0x80000000;
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WPA_PUT_BE32(v + 4, val);
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val = WPA_GET_BE32(v);
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val >>= 1;
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WPA_PUT_BE32(v, val);
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}
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/* Multiplication in GF(2^128) */
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static void gf_mult(const u8 *x, const u8 *y, u8 *z)
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{
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u8 v[16];
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int i, j;
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os_memset(z, 0, 16); /* Z_0 = 0^128 */
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os_memcpy(v, y, 16); /* V_0 = Y */
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for (i = 0; i < 16; i++) {
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for (j = 0; j < 8; j++) {
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if (x[i] & BIT(7 - j)) {
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/* Z_(i + 1) = Z_i XOR V_i */
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xor_block(z, v);
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} else {
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/* Z_(i + 1) = Z_i */
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}
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if (v[15] & 0x01) {
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/* V_(i + 1) = (V_i >> 1) XOR R */
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shift_right_block(v);
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/* R = 11100001 || 0^120 */
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v[0] ^= 0xe1;
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} else {
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/* V_(i + 1) = V_i >> 1 */
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shift_right_block(v);
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}
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}
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}
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}
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static void ghash_start(u8 *y)
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{
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/* Y_0 = 0^128 */
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os_memset(y, 0, 16);
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}
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static void ghash(const u8 *h, const u8 *x, size_t xlen, u8 *y)
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{
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size_t m, i;
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const u8 *xpos = x;
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u8 tmp[16];
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m = xlen / 16;
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for (i = 0; i < m; i++) {
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/* Y_i = (Y^(i-1) XOR X_i) dot H */
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xor_block(y, xpos);
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xpos += 16;
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/* dot operation:
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* multiplication operation for binary Galois (finite) field of
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* 2^128 elements */
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gf_mult(y, h, tmp);
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os_memcpy(y, tmp, 16);
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}
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if (x + xlen > xpos) {
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/* Add zero padded last block */
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size_t last = x + xlen - xpos;
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os_memcpy(tmp, xpos, last);
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os_memset(tmp + last, 0, sizeof(tmp) - last);
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/* Y_i = (Y^(i-1) XOR X_i) dot H */
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xor_block(y, tmp);
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/* dot operation:
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* multiplication operation for binary Galois (finite) field of
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* 2^128 elements */
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gf_mult(y, h, tmp);
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os_memcpy(y, tmp, 16);
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}
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/* Return Y_m */
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}
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static void aes_gctr(void *aes, const u8 *icb, const u8 *x, size_t xlen, u8 *y)
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{
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size_t i, n, last;
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u8 cb[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE];
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const u8 *xpos = x;
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u8 *ypos = y;
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if (xlen == 0)
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return;
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n = xlen / 16;
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os_memcpy(cb, icb, AES_BLOCK_SIZE);
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/* Full blocks */
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for (i = 0; i < n; i++) {
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aes_encrypt(aes, cb, ypos);
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xor_block(ypos, xpos);
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xpos += AES_BLOCK_SIZE;
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ypos += AES_BLOCK_SIZE;
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inc32(cb);
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}
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last = x + xlen - xpos;
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if (last) {
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/* Last, partial block */
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aes_encrypt(aes, cb, tmp);
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for (i = 0; i < last; i++)
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*ypos++ = *xpos++ ^ tmp[i];
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}
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}
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/**
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* aes_128_gcm_ae - GCM-AE_K(IV, P, A) with len(IV) = 96
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*/
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int aes_128_gcm_ae(const u8 *key, const u8 *iv,
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const u8 *plain, size_t plain_len,
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const u8 *aad, size_t aad_len, u8 *crypt, u8 *tag)
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{
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u8 H[AES_BLOCK_SIZE];
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u8 J0[AES_BLOCK_SIZE];
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u8 S[16], len_buf[16];
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void *aes;
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size_t iv_len = 12;
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aes = aes_encrypt_init(key, 16);
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if (aes == NULL)
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return -1;
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/* 1. Generate hash subkey H = AES_K(0^128) */
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os_memset(H, 0, sizeof(H));
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aes_encrypt(aes, H, H);
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wpa_hexdump_key(MSG_EXCESSIVE, "Hash subkey H for GHASH", H, sizeof(H));
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/* 2. Prepare block J_0 = IV || 0^31 || 1 [len(IV) = 96] */
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os_memcpy(J0, iv, iv_len);
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os_memset(J0 + iv_len, 0, AES_BLOCK_SIZE - iv_len);
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J0[AES_BLOCK_SIZE - 1] = 0x01;
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/* 3. C = GCTR_K(inc_32(J_0), P) */
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inc32(J0);
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aes_gctr(aes, J0, plain, plain_len, crypt);
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/*
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* 4. u = 128 * ceil[len(C)/128] - len(C)
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* v = 128 * ceil[len(A)/128] - len(A)
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* 5. S = GHASH_H(A || 0^v || C || 0^u || [len(A)]64 || [len(C)]64)
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* (i.e., zero padded to block size A || C and lengths of each in bits)
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*/
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ghash_start(S);
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ghash(H, aad, aad_len, S);
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ghash(H, crypt, plain_len, S);
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WPA_PUT_BE64(len_buf, aad_len * 8);
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WPA_PUT_BE64(len_buf + 8, plain_len * 8);
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ghash(H, len_buf, sizeof(len_buf), S);
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wpa_hexdump_key(MSG_EXCESSIVE, "S = GHASH_H(...)", S, 16);
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/* 6. T = MSB_t(GCTR_K(J_0, S)) */
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J0[AES_BLOCK_SIZE - 1] = 0x01;
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aes_gctr(aes, J0, S, sizeof(S), tag);
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/* 7. Return (C, T) */
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aes_encrypt_deinit(aes);
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return 0;
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}
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/**
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* aes_128_gcm_ad - GCM-AD_K(IV, C, A, T) with len(IV) = 96
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*/
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int aes_128_gcm_ad(const u8 *key, const u8 *iv,
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const u8 *crypt, size_t crypt_len,
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const u8 *aad, size_t aad_len, const u8 *tag, u8 *plain)
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{
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u8 H[AES_BLOCK_SIZE];
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u8 J0[AES_BLOCK_SIZE];
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u8 S[16], T[16], len_buf[16];
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void *aes;
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size_t iv_len = 12;
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aes = aes_encrypt_init(key, 16);
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if (aes == NULL)
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return -1;
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/* 2. Generate hash subkey H = AES_K(0^128) */
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os_memset(H, 0, sizeof(H));
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aes_encrypt(aes, H, H);
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wpa_hexdump_key(MSG_EXCESSIVE, "Hash subkey H for GHASH", H, sizeof(H));
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/* 3. Prepare block J_0 = IV || 0^31 || 1 [len(IV) = 96] */
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os_memcpy(J0, iv, iv_len);
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os_memset(J0 + iv_len, 0, AES_BLOCK_SIZE - iv_len);
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J0[AES_BLOCK_SIZE - 1] = 0x01;
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/* 4. C = GCTR_K(inc_32(J_0), C) */
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inc32(J0);
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aes_gctr(aes, J0, crypt, crypt_len, plain);
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/*
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* 5. u = 128 * ceil[len(C)/128] - len(C)
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* v = 128 * ceil[len(A)/128] - len(A)
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* 6. S = GHASH_H(A || 0^v || C || 0^u || [len(A)]64 || [len(C)]64)
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* (i.e., zero padded to block size A || C and lengths of each in bits)
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*/
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ghash_start(S);
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ghash(H, aad, aad_len, S);
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ghash(H, crypt, crypt_len, S);
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WPA_PUT_BE64(len_buf, aad_len * 8);
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WPA_PUT_BE64(len_buf + 8, crypt_len * 8);
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ghash(H, len_buf, sizeof(len_buf), S);
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wpa_hexdump_key(MSG_EXCESSIVE, "S = GHASH_H(...)", S, 16);
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/* 7. T' = MSB_t(GCTR_K(J_0, S)) */
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J0[AES_BLOCK_SIZE - 1] = 0x01;
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aes_gctr(aes, J0, S, sizeof(S), T);
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aes_encrypt_deinit(aes);
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if (os_memcmp(tag, T, 16) != 0) {
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wpa_printf(MSG_EXCESSIVE, "GCM: Tag mismatch");
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return -1;
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}
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return 0;
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}
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@ -6,8 +6,9 @@
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* - AES-128 CTR mode encryption
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* - AES-128 EAX mode encryption/decryption
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* - AES-128 CBC
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* - AES-128 GCM
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*
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* Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
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* Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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@ -38,5 +39,13 @@ int __must_check aes_128_cbc_encrypt(const u8 *key, const u8 *iv, u8 *data,
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size_t data_len);
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int __must_check aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data,
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size_t data_len);
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int __must_check aes_128_gcm_ae(const u8 *key, const u8 *iv,
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const u8 *plain, size_t plain_len,
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const u8 *aad, size_t aad_len,
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u8 *crypt, u8 *tag);
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int __must_check aes_128_gcm_ad(const u8 *key, const u8 *iv,
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const u8 *crypt, size_t crypt_len,
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const u8 *aad, size_t aad_len, const u8 *tag,
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u8 *plain);
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#endif /* AES_WRAP_H */
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285
wlantest/gcmp.c
285
wlantest/gcmp.c
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@ -11,289 +11,10 @@
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#include "utils/common.h"
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#include "common/ieee802_11_defs.h"
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#include "crypto/aes.h"
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#include "crypto/aes_wrap.h"
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#include "wlantest.h"
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static void inc32(u8 *block)
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{
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u32 val;
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val = WPA_GET_BE32(block + AES_BLOCK_SIZE - 4);
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val++;
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WPA_PUT_BE32(block + AES_BLOCK_SIZE - 4, val);
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}
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static void xor_block(u8 *dst, const u8 *src)
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{
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u32 *d = (u32 *) dst;
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u32 *s = (u32 *) src;
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*d++ ^= *s++;
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*d++ ^= *s++;
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*d++ ^= *s++;
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*d++ ^= *s++;
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}
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static void shift_right_block(u8 *v)
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{
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u32 val;
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val = WPA_GET_BE32(v + 12);
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val >>= 1;
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if (v[11] & 0x01)
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val |= 0x80000000;
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WPA_PUT_BE32(v + 12, val);
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val = WPA_GET_BE32(v + 8);
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val >>= 1;
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if (v[7] & 0x01)
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val |= 0x80000000;
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WPA_PUT_BE32(v + 8, val);
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val = WPA_GET_BE32(v + 4);
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val >>= 1;
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if (v[3] & 0x01)
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val |= 0x80000000;
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WPA_PUT_BE32(v + 4, val);
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val = WPA_GET_BE32(v);
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val >>= 1;
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WPA_PUT_BE32(v, val);
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}
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/* Multiplication in GF(2^128) */
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static void gf_mult(const u8 *x, const u8 *y, u8 *z)
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{
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u8 v[16];
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int i, j;
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os_memset(z, 0, 16); /* Z_0 = 0^128 */
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os_memcpy(v, y, 16); /* V_0 = Y */
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for (i = 0; i < 16; i++) {
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for (j = 0; j < 8; j++) {
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if (x[i] & BIT(7 - j)) {
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/* Z_(i + 1) = Z_i XOR V_i */
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xor_block(z, v);
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} else {
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/* Z_(i + 1) = Z_i */
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}
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if (v[15] & 0x01) {
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/* V_(i + 1) = (V_i >> 1) XOR R */
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shift_right_block(v);
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/* R = 11100001 || 0^120 */
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v[0] ^= 0xe1;
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} else {
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/* V_(i + 1) = V_i >> 1 */
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shift_right_block(v);
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}
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}
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}
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}
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static void ghash_start(u8 *y)
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{
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/* Y_0 = 0^128 */
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os_memset(y, 0, 16);
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}
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static void ghash(const u8 *h, const u8 *x, size_t xlen, u8 *y)
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{
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size_t m, i;
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const u8 *xpos = x;
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u8 tmp[16];
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m = xlen / 16;
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for (i = 0; i < m; i++) {
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/* Y_i = (Y^(i-1) XOR X_i) dot H */
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xor_block(y, xpos);
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xpos += 16;
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/* dot operation:
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* multiplication operation for binary Galois (finite) field of
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* 2^128 elements */
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gf_mult(y, h, tmp);
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os_memcpy(y, tmp, 16);
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}
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if (x + xlen > xpos) {
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/* Add zero padded last block */
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size_t last = x + xlen - xpos;
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os_memcpy(tmp, xpos, last);
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os_memset(tmp + last, 0, sizeof(tmp) - last);
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/* Y_i = (Y^(i-1) XOR X_i) dot H */
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xor_block(y, tmp);
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/* dot operation:
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* multiplication operation for binary Galois (finite) field of
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* 2^128 elements */
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gf_mult(y, h, tmp);
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os_memcpy(y, tmp, 16);
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}
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/* Return Y_m */
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}
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||||
|
||||
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];
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* aes_gcm_ae - GCM-AE_K(IV, P, A) with len(IV) = 96
|
||||
*/
|
||||
static int aes_gcm_ae(const u8 *key, const u8 *iv,
|
||||
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], len_buf[16];
|
||||
void *aes;
|
||||
size_t iv_len = 12;
|
||||
|
||||
aes = aes_encrypt_init(key, 16);
|
||||
if (aes == NULL)
|
||||
return -1;
|
||||
|
||||
/* 1. Generate hash subkey H = AES_K(0^128) */
|
||||
os_memset(H, 0, sizeof(H));
|
||||
aes_encrypt(aes, H, H);
|
||||
wpa_hexdump_key(MSG_EXCESSIVE, "Hash subkey H for GHASH", H, sizeof(H));
|
||||
|
||||
/* 2. 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;
|
||||
|
||||
/* 3. C = GCTR_K(inc_32(J_0), P) */
|
||||
inc32(J0);
|
||||
aes_gctr(aes, J0, plain, plain_len, crypt);
|
||||
|
||||
/*
|
||||
* 4. u = 128 * ceil[len(C)/128] - len(C)
|
||||
* v = 128 * ceil[len(A)/128] - len(A)
|
||||
* 5. 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, plain_len, S);
|
||||
WPA_PUT_BE64(len_buf, aad_len * 8);
|
||||
WPA_PUT_BE64(len_buf + 8, plain_len * 8);
|
||||
ghash(H, len_buf, sizeof(len_buf), S);
|
||||
|
||||
wpa_hexdump_key(MSG_EXCESSIVE, "S = GHASH_H(...)", S, 16);
|
||||
|
||||
/* 6. T = MSB_t(GCTR_K(J_0, S)) */
|
||||
J0[AES_BLOCK_SIZE - 1] = 0x01;
|
||||
aes_gctr(aes, J0, S, sizeof(S), tag);
|
||||
|
||||
/* 7. Return (C, T) */
|
||||
|
||||
aes_encrypt_deinit(aes);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* aes_gcm_ad - GCM-AD_K(IV, C, A, T) with len(IV) = 96
|
||||
*/
|
||||
static int aes_gcm_ad(const u8 *key, const u8 *iv,
|
||||
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], len_buf[16];
|
||||
void *aes;
|
||||
size_t iv_len = 12;
|
||||
|
||||
aes = aes_encrypt_init(key, 16);
|
||||
if (aes == NULL)
|
||||
return -1;
|
||||
|
||||
/* 2. Generate hash subkey H = AES_K(0^128) */
|
||||
os_memset(H, 0, sizeof(H));
|
||||
aes_encrypt(aes, H, H);
|
||||
wpa_hexdump_key(MSG_EXCESSIVE, "Hash subkey H for GHASH", H, sizeof(H));
|
||||
|
||||
/* 3. 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;
|
||||
|
||||
/* 4. C = GCTR_K(inc_32(J_0), C) */
|
||||
inc32(J0);
|
||||
aes_gctr(aes, J0, crypt, crypt_len, plain);
|
||||
|
||||
/*
|
||||
* 5. u = 128 * ceil[len(C)/128] - len(C)
|
||||
* v = 128 * ceil[len(A)/128] - len(A)
|
||||
* 6. 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);
|
||||
|
||||
/* 7. T' = MSB_t(GCTR_K(J_0, S)) */
|
||||
J0[AES_BLOCK_SIZE - 1] = 0x01;
|
||||
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;
|
||||
}
|
||||
|
||||
|
||||
static void gcmp_aad_nonce(const struct ieee80211_hdr *hdr, const u8 *data,
|
||||
u8 *aad, size_t *aad_len, u8 *nonce)
|
||||
{
|
||||
|
|
@ -374,7 +95,7 @@ u8 * gcmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
|
|||
wpa_hexdump(MSG_EXCESSIVE, "GCMP AAD", aad, aad_len);
|
||||
wpa_hexdump(MSG_EXCESSIVE, "GCMP nonce", nonce, sizeof(nonce));
|
||||
|
||||
if (aes_gcm_ad(tk, nonce, m, mlen, aad, aad_len, m + mlen, plain) <
|
||||
if (aes_128_gcm_ad(tk, nonce, m, mlen, aad, aad_len, m + mlen, plain) <
|
||||
0) {
|
||||
u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
|
||||
wpa_printf(MSG_INFO, "Invalid GCMP frame: A1=" MACSTR
|
||||
|
|
@ -425,7 +146,7 @@ u8 * gcmp_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
|
|||
wpa_hexdump(MSG_EXCESSIVE, "GCMP AAD", aad, aad_len);
|
||||
wpa_hexdump(MSG_EXCESSIVE, "GCMP nonce", nonce, sizeof(nonce));
|
||||
|
||||
if (aes_gcm_ae(tk, nonce, frame + hdrlen, plen, aad, aad_len,
|
||||
if (aes_128_gcm_ae(tk, nonce, frame + hdrlen, plen, aad, aad_len,
|
||||
pos, pos + plen) < 0) {
|
||||
os_free(crypt);
|
||||
return NULL;
|
||||
|
|
|
|||
Loading…
Reference in a new issue