#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> // test #include <openssl/ssl.h> #include <openssl/err.h> #include <openssl/bio.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 = NULL; uint32_t local_count; size_t size = 4; uint8_t data[16]; CMAC_CTX *cmac_ctx = NULL; const EVP_CIPHER *cipher = EVP_aes_128_cbc(); uint32_t zero_bit = 0; uint32_t m_length; int ret; DevAssert(stream_cipher != NULL); DevAssert(stream_cipher->key != NULL); DevAssert(stream_cipher->key_length > 0); 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("\nKey:"); for (i = 0; i < stream_cipher->key_length; i++) printf("%02x", stream_cipher->key[i]); printf("\nMessage:"); for (i = 0; i < m_length; i++) printf("%02x", stream_cipher->message[i]); printf("\n"); } #endif cmac_ctx = CMAC_CTX_new(); ret = CMAC_Init(cmac_ctx, stream_cipher->key, stream_cipher->key_length, cipher, NULL); ret = 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 < size; i++) printf("%02x", data[i]); printf("\n"); } #endif memcpy(out, data, 4); free(m); return 0; }