90 lines
1.9 KiB
C
90 lines
1.9 KiB
C
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include "secu_defs.h"
|
|
|
|
#include <openssl/aes.h>
|
|
#include <openssl/cmac.h>
|
|
#include <openssl/evp.h>
|
|
|
|
#include "assertions.h"
|
|
#include "conversions.h"
|
|
|
|
// #define SECU_DEBUG
|
|
|
|
/*!
|
|
* @brief Create integrity cmac t for a given message.
|
|
* @param[in] stream_cipher Structure containing various variables to setup encoding
|
|
* @param[out] out For EIA2 the output string is 32 bits long
|
|
*/
|
|
int nas_stream_encrypt_eia2(nas_stream_cipher_t *stream_cipher, uint8_t out[4])
|
|
{
|
|
uint8_t *m;
|
|
uint32_t local_count;
|
|
size_t size = 4;
|
|
|
|
uint8_t data[16];
|
|
|
|
CMAC_CTX *cmac_ctx;
|
|
|
|
uint32_t zero_bit = 0;
|
|
uint32_t m_length;
|
|
|
|
DevAssert(stream_cipher != NULL);
|
|
DevAssert(stream_cipher->key != NULL);
|
|
DevAssert(out != NULL);
|
|
|
|
memset(data, 0, 16);
|
|
|
|
zero_bit = stream_cipher->blength & 0x7;
|
|
|
|
m_length = stream_cipher->blength >> 3;
|
|
if (zero_bit > 0)
|
|
m_length += 1;
|
|
|
|
local_count = hton_int32(stream_cipher->count);
|
|
|
|
m = calloc(m_length + 8, sizeof(uint8_t));
|
|
|
|
memcpy(&m[0], &local_count, 4);
|
|
m[4] = ((stream_cipher->bearer & 0x1F) << 3) | ((stream_cipher->direction & 0x01) << 2);
|
|
|
|
memcpy(&m[8], stream_cipher->message, m_length);
|
|
|
|
#if defined(SECU_DEBUG)
|
|
{
|
|
int i;
|
|
printf("Byte length: %u, Zero bits: %u\nm: ", m_length + 8, zero_bit);
|
|
for (i = 0; i < m_length + 8; i++)
|
|
printf("%02x", m[i]);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
|
|
cmac_ctx = CMAC_CTX_new();
|
|
|
|
CMAC_Init(cmac_ctx, stream_cipher->key, stream_cipher->key_length, EVP_aes_128_cbc(), NULL);
|
|
CMAC_Update(cmac_ctx, m, m_length + 8);
|
|
|
|
CMAC_Final(cmac_ctx, data, &size);
|
|
|
|
CMAC_CTX_free(cmac_ctx);
|
|
|
|
#if defined(SECU_DEBUG)
|
|
{
|
|
int i;
|
|
printf("out: ");
|
|
for (i = 0; i < 16; i++)
|
|
printf("%02x", data[i]);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
|
|
memcpy(out, data, 4);
|
|
free(m);
|
|
|
|
return 0;
|
|
}
|