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/*
* Copyright (c) 2000-2002 by Solar Designer. See LICENSE.
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include "passwdqc.h"
#define SEPARATORS "_,.;:-!&"
static int read_loop(int fd, char *buffer, int count)
{
int offset, block;
offset = 0;
while (count > 0) {
block = read(fd, &buffer[offset], count);
if (block < 0) {
if (errno == EINTR) continue;
return block;
}
if (!block) return offset;
offset += block;
count -= block;
}
return offset;
}
char *_passwdqc_random(passwdqc_params_t *params)
{
static char output[0x100];
int bits;
int use_separators, count, i;
unsigned int length;
char *start, *end;
int fd;
unsigned char bytes[2];
if (!(bits = params->random_bits))
return NULL;
count = 1 + ((bits - 12) + 14) / 15;
use_separators = ((bits + 11) / 12 != count);
length = count * 7 - 1;
if (length >= sizeof(output) || (int)length > params->max)
return NULL;
if ((fd = open("/dev/urandom", O_RDONLY)) < 0) return NULL;
length = 0;
do {
if (read_loop(fd, bytes, sizeof(bytes)) != sizeof(bytes)) {
close(fd);
return NULL;
}
i = (((int)bytes[1] & 0x0f) << 8) | (int)bytes[0];
start = _passwdqc_wordset_4k[i];
end = memchr(start, '\0', 6);
if (!end) end = start + 6;
if (length + (end - start) >= sizeof(output) - 1) {
close(fd);
return NULL;
}
memcpy(&output[length], start, end - start);
length += end - start;
bits -= 12;
if (use_separators && bits > 3) {
i = ((int)bytes[1] & 0x70) >> 4;
output[length++] = SEPARATORS[i];
bits -= 3;
} else
if (bits > 0)
output[length++] = ' ';
} while (bits > 0);
memset(bytes, 0, sizeof(bytes));
output[length] = '\0';
close(fd);
return output;
}
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