/* 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 <stdio.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.empty() && 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[16 + 1] = "0123456789abcdef";
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;
}