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- /* Copyright (c) 2015, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
- #include <string>
- #include <vector>
-
- #include <stdint.h>
- #include <stdlib.h>
-
- #include <openssl/rand.h>
-
- #include "internal.h"
-
-
- static const struct argument kArguments[] = {
- {
- "-hex", kBooleanArgument,
- "Hex encoded output."
- },
- {
- "", kOptionalArgument, "",
- },
- };
-
- bool Rand(const std::vector<std::string> &args) {
- bool forever = true, hex = false;
- size_t len = 0;
-
- if (!args.empty()) {
- std::vector<std::string> args_copy(args);
- const std::string &last_arg = args.back();
-
- if (last_arg.size() > 0 && last_arg[0] != '-') {
- char *endptr;
- unsigned long long num = strtoull(last_arg.c_str(), &endptr, 10);
- if (*endptr == 0) {
- len = num;
- forever = false;
- args_copy.pop_back();
- }
- }
-
- std::map<std::string, std::string> args_map;
- if (!ParseKeyValueArguments(&args_map, args_copy, kArguments)) {
- PrintUsage(kArguments);
- return false;
- }
-
- hex = args_map.count("-hex") > 0;
- }
-
- uint8_t buf[4096];
- uint8_t hex_buf[8192];
-
- size_t done = 0;
- while (forever || done < len) {
- size_t todo = sizeof(buf);
- if (!forever && todo > len - done) {
- todo = len - done;
- }
- RAND_bytes(buf, todo);
- if (hex) {
- static const char hextable[] = "0123456789abdef";
- for (unsigned i = 0; i < todo; i++) {
- hex_buf[i*2] = hextable[buf[i] >> 4];
- hex_buf[i*2 + 1] = hextable[buf[i] & 0xf];
- }
- if (fwrite(hex_buf, todo*2, 1, stdout) != 1) {
- return false;
- }
- } else {
- if (fwrite(buf, todo, 1, stdout) != 1) {
- return false;
- }
- }
- done += todo;
- }
-
- if (hex && fwrite("\n", 1, 1, stdout) != 1) {
- return false;
- }
-
- return true;
- }
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