| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. |
| */ |
| |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdbool.h> |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <string.h> |
| #include <fcntl.h> |
| #ifdef __linux__ |
| #include <sys/syscall.h> |
| #endif |
| #ifdef __APPLE__ |
| #include <AvailabilityMacros.h> |
| #ifndef MAC_OS_X_VERSION_10_12 |
| #define MAC_OS_X_VERSION_10_12 101200 |
| #endif |
| #if MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_12 |
| #include <sys/random.h> |
| #endif |
| #endif |
| |
| #include "curve25519.h" |
| #include "encoding.h" |
| #include "subcommands.h" |
| |
| #ifndef _WIN32 |
| static inline bool __attribute__((__warn_unused_result__)) get_random_bytes(uint8_t *out, size_t len) |
| { |
| ssize_t ret = 0; |
| size_t i; |
| int fd; |
| |
| if (len > 256) { |
| errno = EOVERFLOW; |
| return false; |
| } |
| |
| #if defined(__OpenBSD__) || (defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_12) || (defined(__GLIBC__) && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25))) |
| if (!getentropy(out, len)) |
| return true; |
| #endif |
| |
| #if defined(__NR_getrandom) && defined(__linux__) |
| if (syscall(__NR_getrandom, out, len, 0) == (ssize_t)len) |
| return true; |
| #endif |
| |
| fd = open("/dev/urandom", O_RDONLY); |
| if (fd < 0) |
| return false; |
| for (errno = 0, i = 0; i < len; i += ret, ret = 0) { |
| ret = read(fd, out + i, len - i); |
| if (ret <= 0) { |
| ret = errno ? -errno : -EIO; |
| break; |
| } |
| } |
| close(fd); |
| errno = -ret; |
| return i == len; |
| } |
| #else |
| #include <ntsecapi.h> |
| static inline bool __attribute__((__warn_unused_result__)) get_random_bytes(uint8_t *out, size_t len) |
| { |
| return RtlGenRandom(out, len); |
| } |
| #endif |
| |
| int genkey_main(int argc, const char *argv[]) |
| { |
| uint8_t key[WG_KEY_LEN]; |
| char base64[WG_KEY_LEN_BASE64]; |
| struct stat stat; |
| |
| if (argc != 1) { |
| fprintf(stderr, "Usage: %s %s\n", PROG_NAME, argv[0]); |
| return 1; |
| } |
| |
| if (!fstat(STDOUT_FILENO, &stat) && S_ISREG(stat.st_mode) && stat.st_mode & S_IRWXO) |
| fputs("Warning: writing to world accessible file.\nConsider setting the umask to 077 and trying again.\n", stderr); |
| |
| if (!get_random_bytes(key, WG_KEY_LEN)) { |
| perror("getrandom"); |
| return 1; |
| } |
| if (!strcmp(argv[0], "genkey")) |
| curve25519_clamp_secret(key); |
| |
| key_to_base64(base64, key); |
| puts(base64); |
| return 0; |
| } |