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00016 #include "includes.h"
00017
00018 #include "common.h"
00019 #include "aes.h"
00020 #include "aes_wrap.h"
00021
00022 static void gf_mulx(u8 *pad)
00023 {
00024 int i, carry;
00025
00026 carry = pad[0] & 0x80;
00027 for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
00028 pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
00029 pad[AES_BLOCK_SIZE - 1] <<= 1;
00030 if (carry)
00031 pad[AES_BLOCK_SIZE - 1] ^= 0x87;
00032 }
00033
00034
00048 int omac1_aes_128_vector(const u8 *key, size_t num_elem,
00049 const u8 *addr[], const size_t *len, u8 *mac)
00050 {
00051 void *ctx;
00052 u8 cbc[AES_BLOCK_SIZE], pad[AES_BLOCK_SIZE];
00053 const u8 *pos, *end;
00054 size_t i, e, left, total_len;
00055
00056 ctx = aes_encrypt_init(key, 16);
00057 if (ctx == NULL)
00058 return -1;
00059 os_memset(cbc, 0, AES_BLOCK_SIZE);
00060
00061 total_len = 0;
00062 for (e = 0; e < num_elem; e++)
00063 total_len += len[e];
00064 left = total_len;
00065
00066 e = 0;
00067 pos = addr[0];
00068 end = pos + len[0];
00069
00070 while (left >= AES_BLOCK_SIZE) {
00071 for (i = 0; i < AES_BLOCK_SIZE; i++) {
00072 cbc[i] ^= *pos++;
00073 if (pos >= end) {
00074 e++;
00075 pos = addr[e];
00076 end = pos + len[e];
00077 }
00078 }
00079 if (left > AES_BLOCK_SIZE)
00080 aes_encrypt(ctx, cbc, cbc);
00081 left -= AES_BLOCK_SIZE;
00082 }
00083
00084 os_memset(pad, 0, AES_BLOCK_SIZE);
00085 aes_encrypt(ctx, pad, pad);
00086 gf_mulx(pad);
00087
00088 if (left || total_len == 0) {
00089 for (i = 0; i < left; i++) {
00090 cbc[i] ^= *pos++;
00091 if (pos >= end) {
00092 e++;
00093 pos = addr[e];
00094 end = pos + len[e];
00095 }
00096 }
00097 cbc[left] ^= 0x80;
00098 gf_mulx(pad);
00099 }
00100
00101 for (i = 0; i < AES_BLOCK_SIZE; i++)
00102 pad[i] ^= cbc[i];
00103 aes_encrypt(ctx, pad, mac);
00104 aes_encrypt_deinit(ctx);
00105 return 0;
00106 }
00107
00108
00121 int omac1_aes_128(const u8 *key, const u8 *data, size_t data_len, u8 *mac)
00122 {
00123 return omac1_aes_128_vector(key, 1, &data, &data_len, mac);
00124 }