Files
openairinterface5g/openair2/UTIL/OSA/osa_stream_eea.c
T
2013-11-28 10:42:46 +00:00

140 lines
3.7 KiB
C

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <nettle/nettle-meta.h>
#include <nettle/aes.h>
#include <nettle/ctr.h>
#include "UTIL/LOG/log.h"
#include "assertions.h"
#include "osa_defs.h"
#include "osa_internal.h"
int stream_encrypt_eea0(stream_cipher_t *stream_cipher, uint8_t **out)
{
uint8_t *data = NULL;
uint32_t byte_length;
DevAssert(stream_cipher != NULL);
DevAssert(out != NULL);
LOG_D(OSA, "Entering stream_encrypt_eea0, bits length %u, bearer %u, "
"count %u, direction %s\n", stream_cipher->blength,
stream_cipher->bearer, stream_cipher->count, stream_cipher->direction == SECU_DIRECTION_DOWNLINK ?
"Downlink" : "Uplink");
byte_length = (stream_cipher->blength + 7) >> 3;
if (*out == NULL) {
/* User provided output buffer */
data = malloc(byte_length);
*out = data;
} else {
data = *out;
}
memcpy (data, stream_cipher->message, byte_length);
return 0;
}
int stream_encrypt_eea2(stream_cipher_t *stream_cipher, uint8_t **out)
{
uint8_t m[16];
uint32_t local_count;
void *ctx;
uint8_t *data = NULL;
uint32_t zero_bit = 0;
uint32_t byte_length;
DevAssert(stream_cipher != NULL);
DevAssert(out != NULL);
LOG_D(OSA, "Entering stream_encrypt_eea2, bits length %u, bearer %u, "
"count %u, direction %s\n", stream_cipher->blength,
stream_cipher->bearer, stream_cipher->count, stream_cipher->direction == SECU_DIRECTION_DOWNLINK ?
"Downlink" : "Uplink");
zero_bit = stream_cipher->blength & 0x7;
byte_length = stream_cipher->blength >> 3;
if (zero_bit > 0)
byte_length += 1;
ctx = malloc(nettle_aes128.context_size);
if (*out == NULL) {
/* User provided output buffer */
data = malloc(byte_length);
*out = data;
} else {
data = *out;
}
local_count = hton_int32(stream_cipher->count);
memset(m, 0, sizeof(m));
memcpy(&m[0], &local_count, 4);
m[4] = ((stream_cipher->bearer & 0x1F) << 3) |
((stream_cipher->direction & 0x01) << 2);
/* Other bits are 0 */
#if defined(SECU_DEBUG)
{
int i;
char payload[6 * byte_length + 1];
int index = 0;
for (i = 0; i < byte_length; i++)
index += sprintf(&payload[index], "0x%02x ", stream_cipher->message[i]);
LOG_D(OSA, "Original message: %s\n", payload);
}
#endif
nettle_aes128.set_encrypt_key(ctx, stream_cipher->key_length,
stream_cipher->key);
nettle_ctr_crypt(ctx, nettle_aes128.encrypt,
nettle_aes128.block_size, m,
byte_length, data, stream_cipher->message);
if (zero_bit > 0)
data[byte_length - 1] = data[byte_length - 1] & (uint8_t)(0xFF << (8 - zero_bit));
free(ctx);
#if defined(SECU_DEBUG)
{
int i;
char payload[6 * byte_length + 1];
int index = 0;
for (i = 0; i < byte_length; i++)
index += sprintf(&payload[index], "0x%02x ", data[i]);
LOG_D(OSA, "Encrypted message: %s\n", payload);
}
#endif
return 0;
}
int stream_encrypt(uint8_t algorithm, stream_cipher_t *stream_cipher, uint8_t **out)
{
if (algorithm == EEA0_ALG_ID) {
return stream_encrypt_eea0(stream_cipher, out);
} else if (algorithm == EEA1_128_ALG_ID) {
LOG_E(OSA, "SNOW-3G algorithms are currently not implemented for encryption\n");
return -1;
} else if (algorithm == EEA2_128_ALG_ID) {
return stream_encrypt_eea2(stream_cipher, out);
}
LOG_E(OSA, "Provided encryption algorithm is currently not supported = %u\n", algorithm);
return -1;
}