860 lines
30 KiB
C
860 lines
30 KiB
C
/* secure_channel.c - Secure Channel library implementation using TinyCrypt or OpenSSL */
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#define OPENSSL_API_COMPAT 0x10100000L
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#include "secure_channel.h"
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#include "../lib/debug_config.h"
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#include "../lib/platform_compat.h"
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#include <string.h>
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#include <stddef.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <sys/time.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include "crc32.h"
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#include "../lib/sha256.h"
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// To switch between implementations, define USE_OPENSSL before including/compiling.
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// If USE_OPENSSL is defined, use OpenSSL; otherwise, use TinyCrypt (original logic).
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// The core logic (e.g., nonce building, CRC, session key derivation as memcpy, counters, etc.) remains unchanged.
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#ifdef USE_OPENSSL
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#include <openssl/bn.h>
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#include <openssl/evp.h>
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#include <openssl/ec.h>
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#include <openssl/rand.h>
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#include <openssl/sha.h>
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#include <openssl/err.h>
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#else
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#include "../tinycrypt/lib/include/tinycrypt/ecc.h"
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#include "../tinycrypt/lib/include/tinycrypt/ecc_dh.h"
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#include "../tinycrypt/lib/include/tinycrypt/aes.h"
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#include "../tinycrypt/lib/include/tinycrypt/ccm_mode.h"
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#include "../tinycrypt/lib/include/tinycrypt/constants.h"
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#include "../tinycrypt/lib/include/tinycrypt/ecc_platform_specific.h"
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#include "../tinycrypt/lib/include/tinycrypt/sha256.h"
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#endif
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#include "../lib/platform_compat.h"
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static uint8_t sc_urandom_seed[8] = {0};
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static int sc_urandom_initialized = 0;
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static void sc_init_random_seed(void)
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{
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if (random_bytes(sc_urandom_seed, 8) == 0) {
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sc_urandom_initialized = 1;
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}
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}
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// Конвертация hex строки в бинарный формат (common)
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static int hex_to_binary(const char *hex_str, uint8_t *binary, size_t binary_len) {
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if (!hex_str || !binary || strlen(hex_str) != binary_len * 2) return -1;
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for (size_t i = 0; i < binary_len; i++) {
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unsigned int byte;
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if (sscanf(hex_str + i * 2, "%2x", &byte) != 1) return -1;
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binary[i] = (uint8_t)byte;
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}
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return 0;
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}
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sc_status_t sc_init_ctx(sc_context_t *ctx, struct SC_MYKEYS *mykeys) {
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ctx->pk = mykeys;
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ctx->initialized = 1;
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ctx->peer_key_set = 0;
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ctx->session_ready = 0;
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ctx->tx_counter = 0;
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ctx->rx_counter = 0;
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return SC_OK;
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}
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// Common helper functions for input validation and CRC handling
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static sc_status_t validate_encrypt_inputs(sc_context_t *ctx, const uint8_t *plaintext,
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const uint8_t *ciphertext, const size_t *ciphertext_len,
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size_t plaintext_len) {
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if (!ctx || !plaintext || !ciphertext || !ciphertext_len) {
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return SC_ERR_INVALID_ARG;
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}
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if (!ctx->session_ready) {
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return SC_ERR_NOT_INITIALIZED;
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}
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if (plaintext_len == 0) {
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return SC_ERR_INVALID_ARG;
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}
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return SC_OK;
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}
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static sc_status_t validate_decrypt_inputs(sc_context_t *ctx, const uint8_t *ciphertext,
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const uint8_t *plaintext, const size_t *plaintext_len,
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size_t ciphertext_len) {
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if (!ctx || !ciphertext || !plaintext || !plaintext_len) {
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return SC_ERR_INVALID_ARG;
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}
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if (!ctx->session_ready) {
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return SC_ERR_NOT_INITIALIZED;
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}
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if (ciphertext_len < SC_NONCE_SIZE + SC_TAG_SIZE + SC_CRC32_SIZE) {
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return SC_ERR_INVALID_ARG;
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}
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return SC_OK;
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}
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static void append_crc32(const uint8_t *plaintext, size_t plaintext_len, uint8_t *output) {
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memcpy(output, plaintext, plaintext_len);
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uint32_t crc = crc32_calc(plaintext, plaintext_len);
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output[plaintext_len] = (crc >> 0) & 0xFF;
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output[plaintext_len + 1] = (crc >> 8) & 0xFF;
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output[plaintext_len + 2] = (crc >> 16) & 0xFF;
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output[plaintext_len + 3] = (crc >> 24) & 0xFF;
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}
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static sc_status_t verify_and_strip_crc32(uint8_t *plaintext_with_crc, size_t total_len,
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uint8_t *plaintext, size_t *plaintext_len) {
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size_t data_len = total_len - SC_CRC32_SIZE;
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uint32_t received_crc = ((uint32_t)plaintext_with_crc[data_len]) |
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((uint32_t)plaintext_with_crc[data_len + 1] << 8) |
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((uint32_t)plaintext_with_crc[data_len + 2] << 16) |
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((uint32_t)plaintext_with_crc[data_len + 3] << 24);
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uint32_t calc_crc = crc32_calc(plaintext_with_crc, data_len);
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if (received_crc != calc_crc) {
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return SC_ERR_CRC_FAILED;
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}
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memcpy(plaintext, plaintext_with_crc, data_len);
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*plaintext_len = data_len;
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return SC_OK;
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}
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static void sc_derive_session_key(const uint8_t *shared_secret, uint8_t *session_key) {
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SC_SHA256_CTX sha_ctx;
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uint8_t hash[SC_HASH_SIZE];
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sc_sha256_init(&sha_ctx);
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sc_sha256_update(&sha_ctx, shared_secret, SC_SHARED_SECRET_SIZE);
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sc_sha256_update(&sha_ctx, (const uint8_t *)"uTun-v3-session", 15);
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sc_sha256_final(&sha_ctx, hash);
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memcpy(session_key, hash, SC_SESSION_KEY_SIZE);
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}
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#ifdef USE_OPENSSL
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// OpenSSL-specific implementations
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static int sc_rng(uint8_t *dest, unsigned size) {
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if (random_bytes(dest, size) != 0) {
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return 0;
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}
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/* Mix in PID and microtime for additional entropy */
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#ifdef _WIN32
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DWORD pid = GetCurrentProcessId();
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#else
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pid_t pid = getpid();
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#endif
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struct timeval tv;
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utun_gettimeofday(&tv, NULL);
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for (unsigned i = 0; i < size; i++) {
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dest[i] ^= ((pid >> (i % (sizeof(pid) * 8))) & 0xFF);
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dest[i] ^= ((tv.tv_sec >> (i % (sizeof(tv.tv_sec) * 8))) & 0xFF);
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dest[i] ^= ((tv.tv_usec >> (i % (sizeof(tv.tv_usec) * 8))) & 0xFF);
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}
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return 1;
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}
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static int sc_validate_key(const uint8_t *public_key) {
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EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
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if (!group) return -1;
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EC_POINT *point = EC_POINT_new(group);
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if (!point) {
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EC_GROUP_free(group);
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return -1;
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}
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BIGNUM *x = BN_bin2bn(public_key, 32, NULL);
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BIGNUM *y = BN_bin2bn(public_key + 32, 32, NULL);
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if (!x || !y || EC_POINT_set_affine_coordinates(group, point, x, y, NULL) != 1) {
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BN_free(x);
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BN_free(y);
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EC_POINT_free(point);
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EC_GROUP_free(group);
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return -1;
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}
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int result = EC_POINT_is_on_curve(group, point, NULL);
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BN_free(x);
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BN_free(y);
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EC_POINT_free(point);
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EC_GROUP_free(group);
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// To match TinyCrypt return convention in the provided code (0 valid, !=0 invalid)
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return (result == 1) ? 0 : -1;
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}
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sc_status_t sc_generate_keypair(struct SC_MYKEYS *pk) {
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if (!pk) {
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return SC_ERR_INVALID_ARG;
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}
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EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
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if (!group) return SC_ERR_CRYPTO;
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EC_KEY *key = EC_KEY_new();
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if (!key) {
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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if (EC_KEY_set_group(key, group) != 1) {
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EC_KEY_free(key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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// Use custom RNG if needed, but OpenSSL RAND is fine; for consistency, seed if necessary
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if (EC_KEY_generate_key(key) != 1) {
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EC_KEY_free(key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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const BIGNUM *priv = EC_KEY_get0_private_key(key);
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if (BN_bn2binpad(priv, pk->private_key, SC_PRIVKEY_SIZE) != SC_PRIVKEY_SIZE) {
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EC_KEY_free(key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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const EC_POINT *pub_point = EC_KEY_get0_public_key(key);
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uint8_t pub_buf[65];
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if (EC_POINT_point2oct(group, pub_point, POINT_CONVERSION_UNCOMPRESSED, pub_buf, 65, NULL) != 65) {
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EC_KEY_free(key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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memcpy(pk->public_key, pub_buf + 1, SC_PUBKEY_SIZE); // Skip 0x04 prefix
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EC_KEY_free(key);
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EC_GROUP_free(group);
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return SC_OK;
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}
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sc_status_t sc_init_local_keys(struct SC_MYKEYS *mykeys, const char *public_key, const char *private_key) {
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if (!mykeys || !public_key || !private_key) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: invalid arguments");
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return SC_ERR_INVALID_ARG;
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}
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DEBUG_INFO(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: public_key len=%zu, private_key len=%zu",
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strlen(public_key), strlen(private_key));
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if (hex_to_binary(public_key, mykeys->public_key, SC_PUBKEY_SIZE)) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: failed to convert public key from hex");
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return SC_ERR_INVALID_ARG;
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}
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if (hex_to_binary(private_key, mykeys->private_key, SC_PRIVKEY_SIZE)) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: failed to convert private key from hex");
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return SC_ERR_INVALID_ARG;
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}
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if (sc_validate_key(mykeys->public_key) != 0) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: public key validation failed");
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return SC_ERR_INVALID_ARG;
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}
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DEBUG_INFO(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: keys initialized successfully");
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return SC_OK;
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}
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sc_status_t sc_set_peer_public_key(sc_context_t *ctx, const uint8_t *peer_public_key_h, int mode) {
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uint8_t peer_public_key[SC_PUBKEY_SIZE];
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if (mode) {
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if (hex_to_binary((const char*)peer_public_key_h, peer_public_key, SC_PUBKEY_SIZE)) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: invalid hex key format");
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return SC_ERR_INVALID_ARG;
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}
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} else {
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memcpy(peer_public_key, peer_public_key_h, SC_PUBKEY_SIZE);
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}
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if (!ctx) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: invalid ctx");
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return SC_ERR_INVALID_ARG;
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}
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if (!ctx->initialized) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: ctx not initialized");
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return SC_ERR_NOT_INITIALIZED;
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}
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if (sc_validate_key(peer_public_key) != 0) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: invalid key");
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return SC_ERR_INVALID_ARG;
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}
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if (!ctx->pk) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: no private key");
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return SC_ERR_NOT_INITIALIZED;
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}
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EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
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if (!group) return SC_ERR_CRYPTO;
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EC_KEY *my_key = EC_KEY_new();
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if (!my_key) {
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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if (EC_KEY_set_group(my_key, group) != 1) {
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EC_KEY_free(my_key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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BIGNUM *my_priv = BN_bin2bn(ctx->pk->private_key, SC_PRIVKEY_SIZE, NULL);
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if (!my_priv || EC_KEY_set_private_key(my_key, my_priv) != 1) {
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BN_free(my_priv);
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EC_KEY_free(my_key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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EC_POINT *peer_point = EC_POINT_new(group);
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if (!peer_point) {
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BN_free(my_priv);
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EC_KEY_free(my_key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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BIGNUM *x = BN_bin2bn(peer_public_key, 32, NULL);
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BIGNUM *y = BN_bin2bn(peer_public_key + 32, 32, NULL);
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if (!x || !y || EC_POINT_set_affine_coordinates(group, peer_point, x, y, NULL) != 1) {
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BN_free(x);
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BN_free(y);
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BN_free(my_priv);
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EC_POINT_free(peer_point);
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EC_KEY_free(my_key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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uint8_t shared_secret[SC_SHARED_SECRET_SIZE];
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int len = ECDH_compute_key(shared_secret, SC_SHARED_SECRET_SIZE, peer_point, my_key, NULL);
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if (len != SC_SHARED_SECRET_SIZE) {
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DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: shared secret error");
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BN_free(x);
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BN_free(y);
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BN_free(my_priv);
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EC_POINT_free(peer_point);
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EC_KEY_free(my_key);
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EC_GROUP_free(group);
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return SC_ERR_CRYPTO;
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}
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sc_derive_session_key(shared_secret, ctx->session_key);
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memcpy(ctx->peer_public_key, peer_public_key, SC_PUBKEY_SIZE);
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ctx->peer_key_set = 1;
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ctx->session_ready = 1;
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BN_free(x);
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BN_free(y);
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BN_free(my_priv);
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EC_POINT_free(peer_point);
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EC_KEY_free(my_key);
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EC_GROUP_free(group);
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return SC_OK;
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}
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static void sc_build_nonce(uint64_t counter, uint8_t *nonce_out) {
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SHA256_CTX sha_ctx;
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uint8_t hash[32];
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struct timeval tv;
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uint8_t data[24];
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if (!sc_urandom_initialized) {
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sc_init_random_seed();
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}
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utun_gettimeofday(&tv, NULL);
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memcpy(data, sc_urandom_seed, 8);
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data[8] = (counter >> 0) & 0xFF;
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data[9] = (counter >> 8) & 0xFF;
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data[10] = (counter >> 16) & 0xFF;
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data[11] = (counter >> 24) & 0xFF;
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data[12] = (counter >> 32) & 0xFF;
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data[13] = (counter >> 40) & 0xFF;
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data[14] = (counter >> 48) & 0xFF;
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data[15] = (counter >> 56) & 0xFF;
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data[16] = (tv.tv_sec >> 0) & 0xFF;
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data[17] = (tv.tv_sec >> 8) & 0xFF;
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data[18] = (tv.tv_sec >> 16) & 0xFF;
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data[19] = (tv.tv_sec >> 24) & 0xFF;
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data[20] = (tv.tv_usec >> 0) & 0xFF;
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data[21] = (tv.tv_usec >> 8) & 0xFF;
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data[22] = (tv.tv_usec >> 16) & 0xFF;
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data[23] = (tv.tv_usec >> 24) & 0xFF;
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SHA256_Init(&sha_ctx);
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SHA256_Update(&sha_ctx, data, 24);
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SHA256_Final(hash, &sha_ctx);
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memcpy(nonce_out, hash, SC_NONCE_SIZE);
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}
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sc_status_t sc_encrypt(sc_context_t *ctx, const uint8_t *plaintext, size_t plaintext_len, uint8_t *ciphertext, size_t *ciphertext_len) {
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sc_status_t status = validate_encrypt_inputs(ctx, plaintext, ciphertext, ciphertext_len, plaintext_len);
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if (status != SC_OK) return status;
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uint8_t plaintext_with_crc[plaintext_len + SC_CRC32_SIZE];
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append_crc32(plaintext, plaintext_len, plaintext_with_crc);
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size_t total_plaintext_len = plaintext_len + SC_CRC32_SIZE;
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uint8_t nonce[SC_NONCE_SIZE];
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sc_build_nonce(ctx->tx_counter, nonce);
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EVP_CIPHER_CTX *ectx = EVP_CIPHER_CTX_new();
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if (!ectx) return SC_ERR_CRYPTO;
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if (EVP_EncryptInit_ex(ectx, EVP_aes_128_ccm(), NULL, NULL, NULL) != 1) {
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EVP_CIPHER_CTX_free(ectx);
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return SC_ERR_CRYPTO;
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}
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if (EVP_CIPHER_CTX_ctrl(ectx, EVP_CTRL_AEAD_SET_IVLEN, SC_NONCE_SIZE, NULL) != 1) {
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EVP_CIPHER_CTX_free(ectx);
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return SC_ERR_CRYPTO;
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}
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if (EVP_CIPHER_CTX_ctrl(ectx, EVP_CTRL_AEAD_SET_TAG, SC_TAG_SIZE, NULL) != 1) {
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EVP_CIPHER_CTX_free(ectx);
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return SC_ERR_CRYPTO;
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}
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if (EVP_EncryptInit_ex(ectx, NULL, NULL, ctx->session_key, nonce) != 1) {
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EVP_CIPHER_CTX_free(ectx);
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return SC_ERR_CRYPTO;
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}
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int outlen;
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uint8_t outbuf[total_plaintext_len];
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if (EVP_EncryptUpdate(ectx, outbuf, &outlen, plaintext_with_crc, total_plaintext_len) != 1 ||
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outlen != (int)total_plaintext_len) {
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EVP_CIPHER_CTX_free(ectx);
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return SC_ERR_CRYPTO;
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}
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int tmp;
|
||
if (EVP_EncryptFinal_ex(ectx, outbuf + outlen, &tmp) != 1) {
|
||
EVP_CIPHER_CTX_free(ectx);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
uint8_t tag[SC_TAG_SIZE];
|
||
if (EVP_CIPHER_CTX_ctrl(ectx, EVP_CTRL_AEAD_GET_TAG, SC_TAG_SIZE, tag) != 1) {
|
||
EVP_CIPHER_CTX_free(ectx);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
memcpy(ciphertext, nonce, SC_NONCE_SIZE);
|
||
memcpy(ciphertext + SC_NONCE_SIZE, outbuf, total_plaintext_len);
|
||
memcpy(ciphertext + SC_NONCE_SIZE + total_plaintext_len, tag, SC_TAG_SIZE);
|
||
*ciphertext_len = SC_NONCE_SIZE + total_plaintext_len + SC_TAG_SIZE;
|
||
ctx->tx_counter++;
|
||
EVP_CIPHER_CTX_free(ectx);
|
||
return SC_OK;
|
||
}
|
||
|
||
sc_status_t sc_decrypt(sc_context_t *ctx, const uint8_t *ciphertext, size_t ciphertext_len, uint8_t *plaintext, size_t *plaintext_len) {
|
||
sc_status_t status = validate_decrypt_inputs(ctx, ciphertext, plaintext, plaintext_len, ciphertext_len);
|
||
if (status != SC_OK) return status;
|
||
|
||
uint8_t nonce[SC_NONCE_SIZE];
|
||
memcpy(nonce, ciphertext, SC_NONCE_SIZE);
|
||
const uint8_t *encrypted_data = ciphertext + SC_NONCE_SIZE;
|
||
size_t encrypted_len = ciphertext_len - SC_NONCE_SIZE;
|
||
size_t total_plaintext_len = encrypted_len - SC_TAG_SIZE;
|
||
uint8_t plaintext_with_crc[total_plaintext_len];
|
||
EVP_CIPHER_CTX *dctx = EVP_CIPHER_CTX_new();
|
||
if (!dctx) return SC_ERR_CRYPTO;
|
||
if (EVP_DecryptInit_ex(dctx, EVP_aes_128_ccm(), NULL, NULL, NULL) != 1) {
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
if (EVP_CIPHER_CTX_ctrl(dctx, EVP_CTRL_AEAD_SET_IVLEN, SC_NONCE_SIZE, NULL) != 1) {
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
if (EVP_CIPHER_CTX_ctrl(dctx, EVP_CTRL_AEAD_SET_TAG, SC_TAG_SIZE, (void *)(encrypted_data + total_plaintext_len)) != 1) {
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
if (EVP_DecryptInit_ex(dctx, NULL, NULL, ctx->session_key, nonce) != 1) {
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
int outlen;
|
||
if (EVP_DecryptUpdate(dctx, plaintext_with_crc, &outlen, encrypted_data, total_plaintext_len) != 1 ||
|
||
outlen != (int)total_plaintext_len) {
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
return SC_ERR_AUTH_FAILED;
|
||
}
|
||
int tmp;
|
||
if (EVP_DecryptFinal_ex(dctx, plaintext_with_crc + outlen, &tmp) != 1) {
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
return SC_ERR_AUTH_FAILED;
|
||
}
|
||
EVP_CIPHER_CTX_free(dctx);
|
||
sc_status_t result = verify_and_strip_crc32(plaintext_with_crc, total_plaintext_len, plaintext, plaintext_len);
|
||
if (result == SC_OK) {
|
||
ctx->rx_counter++;
|
||
}
|
||
return result;
|
||
}
|
||
|
||
sc_status_t sc_compute_public_key_from_private(const uint8_t *private_key, uint8_t *public_key) {
|
||
if (!private_key || !public_key) {
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
|
||
if (!group) return SC_ERR_CRYPTO;
|
||
BIGNUM *priv = BN_bin2bn(private_key, SC_PRIVKEY_SIZE, NULL);
|
||
if (!priv) {
|
||
EC_GROUP_free(group);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
EC_POINT *pub_point = EC_POINT_new(group);
|
||
if (!pub_point) {
|
||
BN_free(priv);
|
||
EC_GROUP_free(group);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
if (EC_POINT_mul(group, pub_point, priv, NULL, NULL, NULL) != 1) {
|
||
EC_POINT_free(pub_point);
|
||
BN_free(priv);
|
||
EC_GROUP_free(group);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
uint8_t pub_buf[65];
|
||
if (EC_POINT_point2oct(group, pub_point, POINT_CONVERSION_UNCOMPRESSED, pub_buf, 65, NULL) != 65) {
|
||
EC_POINT_free(pub_point);
|
||
BN_free(priv);
|
||
EC_GROUP_free(group);
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
memcpy(public_key, pub_buf + 1, SC_PUBKEY_SIZE);
|
||
EC_POINT_free(pub_point);
|
||
BN_free(priv);
|
||
EC_GROUP_free(group);
|
||
return SC_OK;
|
||
}
|
||
|
||
#else
|
||
|
||
// Original TinyCrypt implementations (unchanged logic)
|
||
|
||
static const struct uECC_Curve_t *curve = NULL;
|
||
|
||
static int sc_rng(uint8_t *dest, unsigned size)
|
||
{
|
||
if (random_bytes(dest, size) != 0) {
|
||
return 0;
|
||
}
|
||
/* Mix in PID and microtime for additional entropy */
|
||
#ifdef _WIN32
|
||
DWORD pid = GetCurrentProcessId();
|
||
#else
|
||
pid_t pid = getpid();
|
||
#endif
|
||
struct timeval tv;
|
||
utun_gettimeofday(&tv, NULL);
|
||
for (unsigned i = 0; i < size; i++) {
|
||
dest[i] ^= ((pid >> (i % (sizeof(pid) * 8))) & 0xFF);
|
||
dest[i] ^= ((tv.tv_sec >> (i % (sizeof(tv.tv_sec) * 8))) & 0xFF);
|
||
dest[i] ^= ((tv.tv_usec >> (i % (sizeof(tv.tv_usec) * 8))) & 0xFF);
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
static int sc_validate_key(const uint8_t *public_key)
|
||
{
|
||
if (!curve) {
|
||
curve = uECC_secp256r1();
|
||
}
|
||
int result = uECC_valid_public_key(public_key, curve);
|
||
DEBUG_INFO(DEBUG_CATEGORY_CRYPTO, "sc_validate_key: uECC_valid_public_key returned %d", result);
|
||
return result;
|
||
}
|
||
|
||
sc_status_t sc_generate_keypair(struct SC_MYKEYS *pk)
|
||
{
|
||
if (!pk) {
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
if (!curve) {
|
||
curve = uECC_secp256r1();
|
||
}
|
||
|
||
/* Set custom RNG function */
|
||
uECC_set_rng(sc_rng);
|
||
|
||
/* Try to generate valid key pair (max 10 attempts) */
|
||
for (int attempt = 0; attempt < 10; attempt++) {
|
||
if (!uECC_make_key(pk->public_key, pk->private_key, curve)) {
|
||
continue;
|
||
}
|
||
/* Validate generated public key immediately */
|
||
if (sc_validate_key(pk->public_key) == 0) {
|
||
DEBUG_INFO(DEBUG_CATEGORY_CRYPTO, "sc_generate_keypair: generated valid keypair on attempt %d", attempt + 1);
|
||
return SC_OK;
|
||
}
|
||
DEBUG_WARN(DEBUG_CATEGORY_CRYPTO, "sc_generate_keypair: generated invalid key on attempt %d, retrying...", attempt + 1);
|
||
}
|
||
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_generate_keypair: failed to generate valid keypair after 10 attempts");
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
sc_status_t sc_init_local_keys(struct SC_MYKEYS *mykeys, const char *public_key, const char *private_key) {
|
||
if (!mykeys || !public_key || !private_key) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: invalid arguments");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
if (!curve) {
|
||
curve = uECC_secp256r1();
|
||
}
|
||
|
||
/* Set RNG function for TinyCrypt - must be done before any ECC operations */
|
||
uECC_set_rng(sc_rng);
|
||
|
||
DEBUG_INFO(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: public_key len=%zu, private_key len=%zu",
|
||
strlen(public_key), strlen(private_key));
|
||
|
||
/* Convert hex to binary first */
|
||
if (hex_to_binary(public_key, mykeys->public_key, SC_PUBKEY_SIZE)) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: failed to convert public key from hex");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
if (hex_to_binary(private_key, mykeys->private_key, SC_PRIVKEY_SIZE)) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: failed to convert private key from hex");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
/* Validate the converted binary public key */
|
||
if (sc_validate_key(mykeys->public_key) != 0) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: public key validation failed");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
DEBUG_INFO(DEBUG_CATEGORY_CRYPTO, "sc_init_local_keys: keys initialized successfully");
|
||
return SC_OK;
|
||
}
|
||
|
||
sc_status_t sc_set_peer_public_key(sc_context_t *ctx, const uint8_t *peer_public_key_h, int mode) {
|
||
uint8_t shared_secret[SC_SHARED_SECRET_SIZE];
|
||
uint8_t peer_public_key[SC_PUBKEY_SIZE];
|
||
|
||
if (mode) {
|
||
if (hex_to_binary((const char*)peer_public_key_h, peer_public_key, SC_PUBKEY_SIZE)) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: invalid hex key format");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
}
|
||
else memcpy(peer_public_key, peer_public_key_h, SC_PUBKEY_SIZE);
|
||
|
||
if (!ctx) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: invalid ctx");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
if (!ctx->initialized) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: ctx not initialized");
|
||
return SC_ERR_NOT_INITIALIZED;
|
||
}
|
||
|
||
if (!curve) {
|
||
curve = uECC_secp256r1();
|
||
}
|
||
|
||
/* Validate peer public key */
|
||
if (sc_validate_key(peer_public_key) != 0) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: invalid key");
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
/* Compute shared secret using ECDH */
|
||
if (!ctx->pk) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: no private key");
|
||
return SC_ERR_NOT_INITIALIZED;
|
||
}
|
||
if (!uECC_shared_secret(peer_public_key, ctx->pk->private_key,
|
||
shared_secret, curve)) {
|
||
DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "sc_set_peer_public_key: shared secret error");
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
sc_derive_session_key(shared_secret, ctx->session_key);
|
||
|
||
/* Store peer public key */
|
||
memcpy(ctx->peer_public_key, peer_public_key, SC_PUBKEY_SIZE);
|
||
ctx->peer_key_set = 1;
|
||
|
||
ctx->session_ready = 1;
|
||
|
||
return SC_OK;
|
||
}
|
||
|
||
static void sc_build_nonce(uint64_t counter, uint8_t *nonce_out)
|
||
{
|
||
struct tc_sha256_state_struct sha_ctx;
|
||
uint8_t hash[32];
|
||
struct timeval tv;
|
||
uint8_t data[8 + 8 + 8];
|
||
|
||
if (!sc_urandom_initialized) {
|
||
sc_init_random_seed();
|
||
}
|
||
|
||
utun_gettimeofday(&tv, NULL);
|
||
|
||
memcpy(data, sc_urandom_seed, 8);
|
||
data[8] = (counter >> 0) & 0xFF;
|
||
data[9] = (counter >> 8) & 0xFF;
|
||
data[10] = (counter >> 16) & 0xFF;
|
||
data[11] = (counter >> 24) & 0xFF;
|
||
data[12] = (counter >> 32) & 0xFF;
|
||
data[13] = (counter >> 40) & 0xFF;
|
||
data[14] = (counter >> 48) & 0xFF;
|
||
data[15] = (counter >> 56) & 0xFF;
|
||
data[16] = (tv.tv_sec >> 0) & 0xFF;
|
||
data[17] = (tv.tv_sec >> 8) & 0xFF;
|
||
data[18] = (tv.tv_sec >> 16) & 0xFF;
|
||
data[19] = (tv.tv_sec >> 24) & 0xFF;
|
||
data[20] = (tv.tv_usec >> 0) & 0xFF;
|
||
data[21] = (tv.tv_usec >> 8) & 0xFF;
|
||
data[22] = (tv.tv_usec >> 16) & 0xFF;
|
||
data[23] = (tv.tv_usec >> 24) & 0xFF;
|
||
|
||
tc_sha256_init(&sha_ctx);
|
||
tc_sha256_update(&sha_ctx, data, 24);
|
||
tc_sha256_final(hash, &sha_ctx);
|
||
|
||
memcpy(nonce_out, hash, SC_NONCE_SIZE);
|
||
}
|
||
|
||
sc_status_t sc_encrypt(sc_context_t *ctx, const uint8_t *plaintext, size_t plaintext_len, uint8_t *ciphertext, size_t *ciphertext_len) {
|
||
sc_status_t status = validate_encrypt_inputs(ctx, plaintext, ciphertext, ciphertext_len, plaintext_len);
|
||
if (status != SC_OK) return status;
|
||
|
||
uint8_t nonce[SC_NONCE_SIZE];
|
||
uint8_t plaintext_with_crc[plaintext_len + SC_CRC32_SIZE];
|
||
size_t total_plaintext_len = plaintext_len + SC_CRC32_SIZE;
|
||
uint8_t combined_output[total_plaintext_len + SC_TAG_SIZE];
|
||
struct tc_aes_key_sched_struct sched;
|
||
struct tc_ccm_mode_struct ccm_state;
|
||
|
||
/* Добавляем CRC32 к данным */
|
||
append_crc32(plaintext, plaintext_len, plaintext_with_crc);
|
||
|
||
/* Генерируем nonce с таймером */
|
||
sc_build_nonce(ctx->tx_counter, nonce);
|
||
|
||
/* Initialize AES key schedule */
|
||
if (tc_aes128_set_encrypt_key(&sched, ctx->session_key) != TC_CRYPTO_SUCCESS) {
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
/* Configure CCM mode */
|
||
if (tc_ccm_config(&ccm_state, &sched, nonce, SC_NONCE_SIZE, SC_TAG_SIZE) != TC_CRYPTO_SUCCESS) {
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
/* Encrypt and generate tag */
|
||
if (tc_ccm_generation_encryption(combined_output, sizeof(combined_output),
|
||
NULL, 0, /* no associated data */
|
||
plaintext_with_crc, total_plaintext_len,
|
||
&ccm_state) != TC_CRYPTO_SUCCESS) {
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
/* Copy nonce + ciphertext + tag to output buffer */
|
||
memcpy(ciphertext, nonce, SC_NONCE_SIZE);
|
||
memcpy(ciphertext + SC_NONCE_SIZE, combined_output, total_plaintext_len + SC_TAG_SIZE);
|
||
*ciphertext_len = SC_NONCE_SIZE + total_plaintext_len + SC_TAG_SIZE;
|
||
|
||
ctx->tx_counter++;
|
||
|
||
return SC_OK;
|
||
}
|
||
|
||
sc_status_t sc_decrypt(sc_context_t *ctx,
|
||
const uint8_t *ciphertext,
|
||
size_t ciphertext_len,
|
||
uint8_t *plaintext,
|
||
size_t *plaintext_len)
|
||
{
|
||
sc_status_t status = validate_decrypt_inputs(ctx, ciphertext, plaintext, plaintext_len, ciphertext_len);
|
||
if (status != SC_OK) return status;
|
||
|
||
uint8_t nonce[SC_NONCE_SIZE];
|
||
struct tc_aes_key_sched_struct sched;
|
||
struct tc_ccm_mode_struct ccm_state;
|
||
size_t total_plaintext_len = ciphertext_len - SC_NONCE_SIZE - SC_TAG_SIZE;
|
||
uint8_t plaintext_with_crc[total_plaintext_len];
|
||
|
||
/* Извлекаем nonce из начала ciphertext */
|
||
memcpy(nonce, ciphertext, SC_NONCE_SIZE);
|
||
|
||
/* Ciphertext для расшифровки начинается после nonce */
|
||
const uint8_t *encrypted_data = ciphertext + SC_NONCE_SIZE;
|
||
size_t encrypted_len = ciphertext_len - SC_NONCE_SIZE;
|
||
|
||
/* Initialize AES key schedule */
|
||
if (tc_aes128_set_encrypt_key(&sched, ctx->session_key) != TC_CRYPTO_SUCCESS) {
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
/* Configure CCM mode с извлечённым nonce */
|
||
if (tc_ccm_config(&ccm_state, &sched, nonce, SC_NONCE_SIZE, SC_TAG_SIZE) != TC_CRYPTO_SUCCESS) {
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
|
||
/* Decrypt and verify tag */
|
||
if (tc_ccm_decryption_verification(plaintext_with_crc, total_plaintext_len,
|
||
NULL, 0, /* no associated data */
|
||
encrypted_data, encrypted_len,
|
||
&ccm_state) != TC_CRYPTO_SUCCESS) {
|
||
return SC_ERR_AUTH_FAILED;
|
||
}
|
||
|
||
/* Проверяем CRC32 используя helper-функцию */
|
||
sc_status_t result = verify_and_strip_crc32(plaintext_with_crc, total_plaintext_len, plaintext, plaintext_len);
|
||
if (result == SC_OK) {
|
||
ctx->rx_counter++;
|
||
}
|
||
return result;
|
||
}
|
||
|
||
sc_status_t sc_compute_public_key_from_private(const uint8_t *private_key, uint8_t *public_key) {
|
||
if (!private_key || !public_key) {
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
if (!curve) {
|
||
curve = uECC_secp256r1();
|
||
}
|
||
|
||
if (!uECC_compute_public_key(private_key, public_key, curve)) {
|
||
return SC_ERR_CRYPTO;
|
||
}
|
||
return SC_OK;
|
||
}
|
||
|
||
#endif
|
||
|
||
sc_status_t sc_sha_transcode(const uint8_t *key, size_t key_len, uint8_t *data, size_t data_len) {
|
||
if (!key || !data || key_len == 0 || data_len == 0) {
|
||
return SC_ERR_INVALID_ARG;
|
||
}
|
||
|
||
uint8_t sha_hash[SC_HASH_SIZE];
|
||
SC_SHA256_CTX ctx;
|
||
|
||
sc_sha256_init(&ctx);
|
||
sc_sha256_update(&ctx, key, key_len);
|
||
sc_sha256_final(&ctx, sha_hash);
|
||
|
||
for (size_t i = 0; i < data_len; i++) {
|
||
data[i] ^= sha_hash[i % SC_HASH_SIZE];
|
||
}
|
||
|
||
return SC_OK;
|
||
}
|
||
|
||
sc_status_t sc_obfuscate_pubkey(const uint8_t *salt, const uint8_t *peer_pubkey, const uint8_t *pubkey, uint8_t *output) {
|
||
if (!salt || !peer_pubkey || !pubkey || !output) return SC_ERR_INVALID_ARG;
|
||
|
||
uint8_t sha[SC_HASH_SIZE*2];
|
||
SC_SHA256_CTX ctx;
|
||
|
||
sc_sha256_init(&ctx);
|
||
sc_sha256_update(&ctx, salt, SC_PUBKEY_ENC_SALT_SIZE);
|
||
sc_sha256_update(&ctx, peer_pubkey, SC_PUBKEY_SIZE);
|
||
sc_sha256_final(&ctx, sha);
|
||
|
||
sc_sha256_init(&ctx);
|
||
sc_sha256_update(&ctx, peer_pubkey, SC_PUBKEY_SIZE);
|
||
sc_sha256_update(&ctx, salt, SC_PUBKEY_ENC_SALT_SIZE);
|
||
sc_sha256_final(&ctx, sha+SC_HASH_SIZE);
|
||
|
||
for (size_t i = 0; i < SC_PUBKEY_SIZE; i++) output[i] = pubkey[i] ^ sha[i];
|
||
|
||
return SC_OK;
|
||
}
|