240 lines
6.8 KiB
C
240 lines
6.8 KiB
C
/*
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* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The OpenAirInterface Software Alliance licenses this file to You under
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* the OAI Public License, Version 1.1 (the "License"); you may not use this file
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* except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.openairinterface.org/?page_id=698
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*-------------------------------------------------------------------------------
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* For more information about the OpenAirInterface (OAI) Software Alliance:
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* contact@openairinterface.org
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <string.h>
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#include <nettle/nettle-meta.h>
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#include <nettle/aes.h>
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#include <nettle/ctr.h>
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#include "common/utils/LOG/log.h"
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#include "assertions.h"
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#include "osa_defs.h"
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#include "osa_snow3g.h"
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#include "osa_internal.h"
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int stream_encrypt_eea0(stream_cipher_t *stream_cipher, uint8_t **out)
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{
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uint8_t *data = NULL;
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uint32_t byte_length;
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DevAssert(stream_cipher != NULL);
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DevAssert(out != NULL);
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LOG_D(OSA, "Entering stream_encrypt_eea0, bits length %u, bearer %u, "
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"count %u, direction %s\n", stream_cipher->blength,
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stream_cipher->bearer, stream_cipher->count, stream_cipher->direction == SECU_DIRECTION_DOWNLINK ?
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"Downlink" : "Uplink");
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byte_length = (stream_cipher->blength + 7) >> 3;
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if (*out == NULL) {
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/* User did not provide output buffer */
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data = malloc(byte_length);
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*out = data;
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} else {
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data = *out;
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}
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memcpy (data, stream_cipher->message, byte_length);
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return 0;
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}
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int stream_encrypt_eea1(stream_cipher_t *stream_cipher, uint8_t **out)
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{
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osa_snow_3g_context_t snow_3g_context;
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int n ;
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int i = 0;
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uint32_t zero_bit = 0;
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uint32_t *KS;
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uint32_t K[4],IV[4];
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DevAssert(stream_cipher != NULL);
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DevAssert(stream_cipher->key != NULL);
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DevAssert(stream_cipher->key_length == 16);
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DevAssert(out != NULL);
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n = ( stream_cipher->blength + 31 ) / 32;
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zero_bit = stream_cipher->blength & 0x7;
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memset(&snow_3g_context, 0, sizeof(snow_3g_context));
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/*Initialisation*/
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/* Load the confidentiality key for SNOW 3G initialization as in section
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3.4. */
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memcpy(K+3,stream_cipher->key+0,4); /*K[3] = key[0]; we assume
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K[3]=key[0]||key[1]||...||key[31] , with key[0] the
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* most important bit of key*/
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memcpy(K+2,stream_cipher->key+4,4); /*K[2] = key[1];*/
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memcpy(K+1,stream_cipher->key+8,4); /*K[1] = key[2];*/
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memcpy(K+0,stream_cipher->key+12,4); /*K[0] = key[3]; we assume
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K[0]=key[96]||key[97]||...||key[127] , with key[127] the
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* least important bit of key*/
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K[3] = hton_int32(K[3]);
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K[2] = hton_int32(K[2]);
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K[1] = hton_int32(K[1]);
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K[0] = hton_int32(K[0]);
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/* Prepare the initialization vector (IV) for SNOW 3G initialization as in
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section 3.4. */
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IV[3] = stream_cipher->count;
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IV[2] = ((((uint32_t)stream_cipher->bearer) << 3) | ((((uint32_t)stream_cipher->direction) & 0x1) << 2)) << 24;
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IV[1] = IV[3];
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IV[0] = IV[2];
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/* Run SNOW 3G algorithm to generate sequence of key stream bits KS*/
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osa_snow3g_initialize(K, IV, &snow_3g_context);
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KS = (uint32_t *)malloc(4*n);
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osa_snow3g_generate_key_stream(n,(uint32_t*)KS, &snow_3g_context);
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if (zero_bit > 0) {
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KS[n - 1] = KS[n - 1] & (uint32_t)(0xFFFFFFFF << (8 - zero_bit));
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}
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for (i=0; i<n; i++) {
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KS[i] = hton_int32(KS[i]);
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}
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/* Exclusive-OR the input data with keystream to generate the output bit
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stream */
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for (i=0; i<n*4; i++) {
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stream_cipher->message[i] ^= *(((uint8_t*)KS)+i);
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}
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if (zero_bit > 0) {
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int ceil_index = (stream_cipher->blength+7) >> 3;
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stream_cipher->message[ceil_index - 1] = stream_cipher->message[ceil_index - 1] & (uint8_t)(0xFF << (8 - zero_bit));
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}
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free(KS);
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*out = stream_cipher->message;
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return 0;
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}
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int stream_encrypt_eea2(stream_cipher_t *stream_cipher, uint8_t **out)
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{
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uint8_t m[16];
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uint32_t local_count;
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void *ctx;
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uint8_t *data = NULL;
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uint32_t zero_bit = 0;
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uint32_t byte_length;
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DevAssert(stream_cipher != NULL);
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DevAssert(out != NULL);
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LOG_D(OSA, "Entering stream_encrypt_eea2, bits length %u, bearer %u, "
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"count %u, direction %s\n", stream_cipher->blength,
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stream_cipher->bearer, stream_cipher->count, stream_cipher->direction == SECU_DIRECTION_DOWNLINK ?
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"Downlink" : "Uplink");
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zero_bit = stream_cipher->blength & 0x7;
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byte_length = stream_cipher->blength >> 3;
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if (zero_bit > 0)
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byte_length += 1;
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ctx = malloc(nettle_aes128.context_size);
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if (*out == NULL) {
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/* User provided output buffer */
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data = malloc(byte_length);
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*out = data;
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} else {
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data = *out;
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}
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local_count = hton_int32(stream_cipher->count);
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memset(m, 0, sizeof(m));
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memcpy(&m[0], &local_count, 4);
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m[4] = ((stream_cipher->bearer & 0x1F) << 3) |
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((stream_cipher->direction & 0x01) << 2);
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/* Other bits are 0 */
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#if defined(SECU_DEBUG)
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{
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int i;
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char payload[6 * byte_length + 1];
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int index = 0;
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for (i = 0; i < byte_length; i++)
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index += sprintf(&payload[index], "0x%02x ", stream_cipher->message[i]);
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LOG_D(OSA, "Original message: %s\n", payload);
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}
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#endif
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#if NETTLE_VERSION_MAJOR < 3
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nettle_aes128.set_encrypt_key(ctx, stream_cipher->key_length,
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stream_cipher->key);
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#else
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nettle_aes128.set_encrypt_key(ctx,
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stream_cipher->key);
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#endif
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nettle_ctr_crypt(ctx, nettle_aes128.encrypt,
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nettle_aes128.block_size, m,
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byte_length, data, stream_cipher->message);
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if (zero_bit > 0)
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data[byte_length - 1] = data[byte_length - 1] & (uint8_t)(0xFF << (8 - zero_bit));
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free(ctx);
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#if defined(SECU_DEBUG)
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{
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int i;
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char payload[6 * byte_length + 1];
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int index = 0;
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for (i = 0; i < byte_length; i++)
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index += sprintf(&payload[index], "0x%02x ", data[i]);
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LOG_D(OSA, "Encrypted message: %s\n", payload);
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}
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#endif
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return 0;
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}
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int stream_encrypt(uint8_t algorithm, stream_cipher_t *stream_cipher, uint8_t **out)
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{
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if (algorithm == EEA0_ALG_ID) {
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return stream_encrypt_eea0(stream_cipher, out);
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} else if (algorithm == EEA1_128_ALG_ID) {
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return stream_encrypt_eea1(stream_cipher, out);
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} else if (algorithm == EEA2_128_ALG_ID) {
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return stream_encrypt_eea2(stream_cipher, out);
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}
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LOG_E(OSA, "Provided encryption algorithm is currently not supported = %u\n", algorithm);
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return -1;
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}
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