/* * AES-based functions * * - AES Key Wrap Algorithm (128-bit KEK) (RFC3394) * - One-Key CBC MAC (OMAC1) hash with AES-128 * - AES-128 CTR mode encryption * - AES-128 EAX mode encryption/decryption * - AES-128 CBC * * Copyright (c) 2003-2005, Jouni Malinen * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Alternatively, this software may be distributed under the terms of BSD * license. * * See README and COPYING for more details. */ #include #include #include #include "common.h" #include "aes_wrap.h" #include "crypto.h" #ifndef EAP_TLS_FUNCS #include "aes.c" #endif /* EAP_TLS_FUNCS */ /** * aes_wrap - Wrap keys with AES Key Wrap Algorithm (128-bit KEK) (RFC3394) * @kek: Key encryption key (KEK) * @n: Length of the wrapped key in 64-bit units; e.g., 2 = 128-bit = 16 bytes * @plain: Plaintext key to be wrapped, n * 64 bit * @cipher: Wrapped key, (n + 1) * 64 bit * Returns: 0 on success, -1 on failure */ int aes_wrap(const u8 *kek, int n, const u8 *plain, u8 *cipher) { u8 *a, *r, b[16]; int i, j; void *ctx; a = cipher; r = cipher + 8; /* 1) Initialize variables. */ memset(a, 0xa6, 8); memcpy(r, plain, 8 * n); ctx = aes_encrypt_init(kek, 16); if (ctx == NULL) return -1; /* 2) Calculate intermediate values. * For j = 0 to 5 * For i=1 to n * B = AES(K, A | R[i]) * A = MSB(64, B) ^ t where t = (n*j)+i * R[i] = LSB(64, B) */ for (j = 0; j <= 5; j++) { r = cipher + 8; for (i = 1; i <= n; i++) { memcpy(b, a, 8); memcpy(b + 8, r, 8); aes_encrypt(ctx, b, b); memcpy(a, b, 8); a[7] ^= n * j + i; memcpy(r, b + 8, 8); r += 8; } } aes_encrypt_deinit(ctx); /* 3) Output the results. * * These are already in @cipher due to the location of temporary * variables. */ return 0; } /** * aes_unwrap - Unwrap key with AES Key Wrap Algorithm (128-bit KEK) (RFC3394) * @kek: Key encryption key (KEK) * @n: Length of the wrapped key in 64-bit units; e.g., 2 = 128-bit = 16 bytes * @cipher: Wrapped key to be unwrapped, (n + 1) * 64 bit * @plain: Plaintext key, n * 64 bit * Returns: 0 on success, -1 on failure (e.g., integrity verification failed) */ int aes_unwrap(const u8 *kek, int n, const u8 *cipher, u8 *plain) { u8 a[8], *r, b[16]; int i, j; void *ctx; /* 1) Initialize variables. */ memcpy(a, cipher, 8); r = plain; memcpy(r, cipher + 8, 8 * n); ctx = aes_decrypt_init(kek, 16); if (ctx == NULL) return -1; /* 2) Compute intermediate values. * For j = 5 to 0 * For i = n to 1 * B = AES-1(K, (A ^ t) | R[i]) where t = n*j+i * A = MSB(64, B) * R[i] = LSB(64, B) */ for (j = 5; j >= 0; j--) { r = plain + (n - 1) * 8; for (i = n; i >= 1; i--) { memcpy(b, a, 8); b[7] ^= n * j + i; memcpy(b + 8, r, 8); aes_decrypt(ctx, b, b); memcpy(a, b, 8); memcpy(r, b + 8, 8); r -= 8; } } aes_decrypt_deinit(ctx); /* 3) Output results. * * These are already in @plain due to the location of temporary * variables. Just verify that the IV matches with the expected value. */ for (i = 0; i < 8; i++) { if (a[i] != 0xa6) return -1; } return 0; } #define BLOCK_SIZE 16 static void gf_mulx(u8 *pad) { int i, carry; carry = pad[0] & 0x80; for (i = 0; i < BLOCK_SIZE - 1; i++) pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7); pad[BLOCK_SIZE - 1] <<= 1; if (carry) pad[BLOCK_SIZE - 1] ^= 0x87; } /** * omac1_aes_128 - One-Key CBC MAC (OMAC1) hash with AES-128 * @key: Key for the hash operation * @data: Data buffer for which a MAC is determined * @data: Length of data buffer in bytes * @mac: Buffer for MAC (128 bits, i.e., 16 bytes) * Returns: 0 on success, -1 on failure */ int omac1_aes_128(const u8 *key, const u8 *data, size_t data_len, u8 *mac) { void *ctx; u8 cbc[BLOCK_SIZE], pad[BLOCK_SIZE]; const u8 *pos = data; int i; size_t left = data_len; ctx = aes_encrypt_init(key, 16); if (ctx == NULL) return -1; memset(cbc, 0, BLOCK_SIZE); while (left >= BLOCK_SIZE) { for (i = 0; i < BLOCK_SIZE; i++) cbc[i] ^= *pos++; if (left > BLOCK_SIZE) aes_encrypt(ctx, cbc, cbc); left -= BLOCK_SIZE; } memset(pad, 0, BLOCK_SIZE); aes_encrypt(ctx, pad, pad); gf_mulx(pad); if (left || data_len == 0) { for (i = 0; i < left; i++) cbc[i] ^= *pos++; cbc[left] ^= 0x80; gf_mulx(pad); } for (i = 0; i < BLOCK_SIZE; i++) pad[i] ^= cbc[i]; aes_encrypt(ctx, pad, mac); aes_encrypt_deinit(ctx); return 0; } /** * aes_128_encrypt_block - Perform one AES 128-bit block operation * @key: Key for AES * @in: Input data (16 bytes) * @out: Output of the AES block operation (16 bytes) * Returns: 0 on success, -1 on failure */ int aes_128_encrypt_block(const u8 *key, const u8 *in, u8 *out) { void *ctx; ctx = aes_encrypt_init(key, 16); if (ctx == NULL) return -1; aes_encrypt(ctx, in, out); aes_encrypt_deinit(ctx); return 0; } /** * aes_128_ctr_encrypt - AES-128 CTR mode encryption * @key: Key for encryption (16 bytes) * @nonce: Nonce for counter mode (16 bytes) * @data: Data to encrypt in-place * @data_len: Length of data in bytes * Returns: 0 on success, -1 on failure */ int aes_128_ctr_encrypt(const u8 *key, const u8 *nonce, u8 *data, size_t data_len) { void *ctx; size_t len, left = data_len; int i; u8 *pos = data; u8 counter[BLOCK_SIZE], buf[BLOCK_SIZE]; ctx = aes_encrypt_init(key, 16); if (ctx == NULL) return -1; memcpy(counter, nonce, BLOCK_SIZE); while (left > 0) { aes_encrypt(ctx, counter, buf); len = (left < BLOCK_SIZE) ? left : BLOCK_SIZE; for (i = 0; i < len; i++) pos[i] ^= buf[i]; pos += len; left -= len; for (i = BLOCK_SIZE - 1; i >= 0; i--) { counter[i]++; if (counter[i]) break; } } aes_encrypt_deinit(ctx); return 0; } /** * aes_128_eax_encrypt - AES-128 EAX mode encryption * @key: Key for encryption (16 bytes) * @nonce: Nonce for counter mode * @nonce_len: Nonce length in bytes * @hdr: Header data to be authenticity protected * @hdr_len: Length of the header data bytes * @data: Data to encrypt in-place * @data_len: Length of data in bytes * @tag: 16-byte tag value * Returns: 0 on success, -1 on failure */ int aes_128_eax_encrypt(const u8 *key, const u8 *nonce, size_t nonce_len, const u8 *hdr, size_t hdr_len, u8 *data, size_t data_len, u8 *tag) { u8 *buf; size_t buf_len; u8 nonce_mac[BLOCK_SIZE], hdr_mac[BLOCK_SIZE], data_mac[BLOCK_SIZE]; int i; if (nonce_len > data_len) buf_len = nonce_len; else buf_len = data_len; if (hdr_len > buf_len) buf_len = hdr_len; buf_len += 16; buf = malloc(buf_len); if (buf == NULL) return -1; memset(buf, 0, 15); buf[15] = 0; memcpy(buf + 16, nonce, nonce_len); omac1_aes_128(key, buf, 16 + nonce_len, nonce_mac); buf[15] = 1; memcpy(buf + 16, hdr, hdr_len); omac1_aes_128(key, buf, 16 + hdr_len, hdr_mac); aes_128_ctr_encrypt(key, nonce_mac, data, data_len); buf[15] = 2; memcpy(buf + 16, data, data_len); omac1_aes_128(key, buf, 16 + data_len, data_mac); free(buf); for (i = 0; i < BLOCK_SIZE; i++) tag[i] = nonce_mac[i] ^ data_mac[i] ^ hdr_mac[i]; return 0; } /** * aes_128_eax_decrypt - AES-128 EAX mode decryption * @key: Key for decryption (16 bytes) * @nonce: Nonce for counter mode * @nonce_len: Nonce length in bytes * @hdr: Header data to be authenticity protected * @hdr_len: Length of the header data bytes * @data: Data to encrypt in-place * @data_len: Length of data in bytes * @tag: 16-byte tag value * Returns: 0 on success, -1 on failure, -2 if tag does not match */ int aes_128_eax_decrypt(const u8 *key, const u8 *nonce, size_t nonce_len, const u8 *hdr, size_t hdr_len, u8 *data, size_t data_len, const u8 *tag) { u8 *buf; size_t buf_len; u8 nonce_mac[BLOCK_SIZE], hdr_mac[BLOCK_SIZE], data_mac[BLOCK_SIZE]; int i; if (nonce_len > data_len) buf_len = nonce_len; else buf_len = data_len; if (hdr_len > buf_len) buf_len = hdr_len; buf_len += 16; buf = malloc(buf_len); if (buf == NULL) return -1; memset(buf, 0, 15); buf[15] = 0; memcpy(buf + 16, nonce, nonce_len); omac1_aes_128(key, buf, 16 + nonce_len, nonce_mac); buf[15] = 1; memcpy(buf + 16, hdr, hdr_len); omac1_aes_128(key, buf, 16 + hdr_len, hdr_mac); buf[15] = 2; memcpy(buf + 16, data, data_len); omac1_aes_128(key, buf, 16 + data_len, data_mac); free(buf); for (i = 0; i < BLOCK_SIZE; i++) { if (tag[i] != (nonce_mac[i] ^ data_mac[i] ^ hdr_mac[i])) return -2; } aes_128_ctr_encrypt(key, nonce_mac, data, data_len); return 0; } /** * aes_128_cbc_encrypt - AES-128 CBC encryption * @key: Encryption key * @iv: Encryption IV for CBC mode (16 bytes) * @data: Data to encrypt in-place * @data_len: Length of data in bytes (must be divisible by 16) * Returns: 0 on success, -1 on failure */ int aes_128_cbc_encrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len) { void *ctx; u8 cbc[BLOCK_SIZE]; u8 *pos = data; int i, j, blocks; ctx = aes_encrypt_init(key, 16); if (ctx == NULL) return -1; memcpy(cbc, iv, BLOCK_SIZE); blocks = data_len / BLOCK_SIZE; for (i = 0; i < blocks; i++) { for (j = 0; j < BLOCK_SIZE; j++) cbc[j] ^= pos[j]; aes_encrypt(ctx, cbc, cbc); memcpy(pos, cbc, BLOCK_SIZE); pos += BLOCK_SIZE; } aes_encrypt_deinit(ctx); return 0; } /** * aes_128_cbc_decrypt - AES-128 CBC decryption * @key: Decryption key * @iv: Decryption IV for CBC mode (16 bytes) * @data: Data to decrypt in-place * @data_len: Length of data in bytes (must be divisible by 16) * Returns: 0 on success, -1 on failure */ int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len) { void *ctx; u8 cbc[BLOCK_SIZE], tmp[BLOCK_SIZE]; u8 *pos = data; int i, j, blocks; ctx = aes_decrypt_init(key, 16); if (ctx == NULL) return -1; memcpy(cbc, iv, BLOCK_SIZE); blocks = data_len / BLOCK_SIZE; for (i = 0; i < blocks; i++) { memcpy(tmp, pos, BLOCK_SIZE); aes_decrypt(ctx, pos, pos); for (j = 0; j < BLOCK_SIZE; j++) pos[j] ^= cbc[j]; memcpy(cbc, tmp, BLOCK_SIZE); pos += BLOCK_SIZE; } aes_decrypt_deinit(ctx); return 0; } #ifdef TEST_MAIN #ifdef __i386__ #define rdtscll(val) \ __asm__ __volatile__("rdtsc" : "=A" (val)) static void test_aes_perf(void) { const int num_iters = 10; int i; unsigned int start, end; u8 key[16], pt[16], ct[16]; void *ctx; printf("keySetupEnc:"); for (i = 0; i < num_iters; i++) { rdtscll(start); ctx = aes_encrypt_init(key, 16); rdtscll(end); aes_encrypt_deinit(ctx); printf(" %d", end - start); } printf("\n"); printf("Encrypt:"); ctx = aes_encrypt_init(key, 16); for (i = 0; i < num_iters; i++) { rdtscll(start); aes_encrypt(ctx, pt, ct); rdtscll(end); printf(" %d", end - start); } aes_encrypt_deinit(ctx); printf("\n"); } #endif /* __i386__ */ static int test_eax(void) { u8 msg[] = { 0xF7, 0xFB }; u8 key[] = { 0x91, 0x94, 0x5D, 0x3F, 0x4D, 0xCB, 0xEE, 0x0B, 0xF4, 0x5E, 0xF5, 0x22, 0x55, 0xF0, 0x95, 0xA4 }; u8 nonce[] = { 0xBE, 0xCA, 0xF0, 0x43, 0xB0, 0xA2, 0x3D, 0x84, 0x31, 0x94, 0xBA, 0x97, 0x2C, 0x66, 0xDE, 0xBD }; u8 hdr[] = { 0xFA, 0x3B, 0xFD, 0x48, 0x06, 0xEB, 0x53, 0xFA }; u8 cipher[] = { 0x19, 0xDD, 0x5C, 0x4C, 0x93, 0x31, 0x04, 0x9D, 0x0B, 0xDA, 0xB0, 0x27, 0x74, 0x08, 0xF6, 0x79, 0x67, 0xE5 }; u8 data[sizeof(msg)], tag[BLOCK_SIZE]; memcpy(data, msg, sizeof(msg)); if (aes_128_eax_encrypt(key, nonce, sizeof(nonce), hdr, sizeof(hdr), data, sizeof(data), tag)) { printf("AES-128 EAX mode encryption failed\n"); return 1; } if (memcmp(data, cipher, sizeof(data)) != 0) { printf("AES-128 EAX mode encryption returned invalid cipher " "text\n"); return 1; } if (memcmp(tag, cipher + sizeof(data), BLOCK_SIZE) != 0) { printf("AES-128 EAX mode encryption returned invalid tag\n"); return 1; } if (aes_128_eax_decrypt(key, nonce, sizeof(nonce), hdr, sizeof(hdr), data, sizeof(data), tag)) { printf("AES-128 EAX mode decryption failed\n"); return 1; } if (memcmp(data, msg, sizeof(data)) != 0) { printf("AES-128 EAX mode decryption returned invalid plain " "text\n"); return 1; } return 0; } static int test_cbc(void) { struct cbc_test_vector { u8 key[16]; u8 iv[16]; u8 plain[32]; u8 cipher[32]; size_t len; } vectors[] = { { { 0x06, 0xa9, 0x21, 0x40, 0x36, 0xb8, 0xa1, 0x5b, 0x51, 0x2e, 0x03, 0xd5, 0x34, 0x12, 0x00, 0x06 }, { 0x3d, 0xaf, 0xba, 0x42, 0x9d, 0x9e, 0xb4, 0x30, 0xb4, 0x22, 0xda, 0x80, 0x2c, 0x9f, 0xac, 0x41 }, "Single block msg", { 0xe3, 0x53, 0x77, 0x9c, 0x10, 0x79, 0xae, 0xb8, 0x27, 0x08, 0x94, 0x2d, 0xbe, 0x77, 0x18, 0x1a }, 16 }, { { 0xc2, 0x86, 0x69, 0x6d, 0x88, 0x7c, 0x9a, 0xa0, 0x61, 0x1b, 0xbb, 0x3e, 0x20, 0x25, 0xa4, 0x5a }, { 0x56, 0x2e, 0x17, 0x99, 0x6d, 0x09, 0x3d, 0x28, 0xdd, 0xb3, 0xba, 0x69, 0x5a, 0x2e, 0x6f, 0x58 }, { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f }, { 0xd2, 0x96, 0xcd, 0x94, 0xc2, 0xcc, 0xcf, 0x8a, 0x3a, 0x86, 0x30, 0x28, 0xb5, 0xe1, 0xdc, 0x0a, 0x75, 0x86, 0x60, 0x2d, 0x25, 0x3c, 0xff, 0xf9, 0x1b, 0x82, 0x66, 0xbe, 0xa6, 0xd6, 0x1a, 0xb1 }, 32 } }; int i, ret = 0; u8 *buf; for (i = 0; i < sizeof(vectors) / sizeof(vectors[0]); i++) { struct cbc_test_vector *tv = &vectors[i]; buf = malloc(tv->len); if (buf == NULL) { ret++; break; } memcpy(buf, tv->plain, tv->len); aes_128_cbc_encrypt(tv->key, tv->iv, buf, tv->len); if (memcmp(buf, tv->cipher, tv->len) != 0) { printf("AES-CBC encrypt %d failed\n", i); ret++; } memcpy(buf, tv->cipher, tv->len); aes_128_cbc_decrypt(tv->key, tv->iv, buf, tv->len); if (memcmp(buf, tv->plain, tv->len) != 0) { printf("AES-CBC decrypt %d failed\n", i); ret++; } free(buf); } return ret; } /* OMAC1 AES-128 test vectors from * http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/omac/omac-ad.pdf */ struct omac1_test_vector { u8 k[16]; u8 msg[64]; int msg_len; u8 tag[16]; }; static struct omac1_test_vector test_vectors[] = { { { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c }, { }, 0, { 0xbb, 0x1d, 0x69, 0x29, 0xe9, 0x59, 0x37, 0x28, 0x7f, 0xa3, 0x7d, 0x12, 0x9b, 0x75, 0x67, 0x46 } }, { { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c }, { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a}, 16, { 0x07, 0x0a, 0x16, 0xb4, 0x6b, 0x4d, 0x41, 0x44, 0xf7, 0x9b, 0xdd, 0x9d, 0xd0, 0x4a, 0x28, 0x7c } }, { { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c }, { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a, 0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51, 0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11 }, 40, { 0xdf, 0xa6, 0x67, 0x47, 0xde, 0x9a, 0xe6, 0x30, 0x30, 0xca, 0x32, 0x61, 0x14, 0x97, 0xc8, 0x27 } }, { { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c }, { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a, 0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51, 0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef, 0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 }, 64, { 0x51, 0xf0, 0xbe, 0xbf, 0x7e, 0x3b, 0x9d, 0x92, 0xfc, 0x49, 0x74, 0x17, 0x79, 0x36, 0x3c, 0xfe } }, }; int main(int argc, char *argv[]) { u8 kek[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }; u8 plain[] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff }; u8 crypt[] = { 0x1F, 0xA6, 0x8B, 0x0A, 0x81, 0x12, 0xB4, 0x47, 0xAE, 0xF3, 0x4B, 0xD8, 0xFB, 0x5A, 0x7B, 0x82, 0x9D, 0x3E, 0x86, 0x23, 0x71, 0xD2, 0xCF, 0xE5 }; u8 result[24]; int ret = 0, i; struct omac1_test_vector *tv; if (aes_wrap(kek, 2, plain, result)) { printf("AES-WRAP-128-128 reported failure\n"); ret++; } if (memcmp(result, crypt, 24) != 0) { printf("AES-WRAP-128-128 failed\n"); ret++; } if (aes_unwrap(kek, 2, crypt, result)) { printf("AES-UNWRAP-128-128 reported failure\n"); ret++; } if (memcmp(result, plain, 16) != 0) { int i; printf("AES-UNWRAP-128-128 failed\n"); ret++; for (i = 0; i < 16; i++) printf(" %02x", result[i]); printf("\n"); } #ifdef __i386__ test_aes_perf(); #endif /* __i386__ */ for (i = 0; i < sizeof(test_vectors) / sizeof(test_vectors[0]); i++) { tv = &test_vectors[i]; omac1_aes_128(tv->k, tv->msg, tv->msg_len, result); if (memcmp(result, tv->tag, 16) != 0) { printf("OMAC1-AES-128 test vector %d failed\n", i); ret++; } } ret += test_eax(); ret += test_cbc(); if (ret) printf("FAILED!\n"); return ret; } #endif /* TEST_MAIN */