/* initialize an rc4 key. If possible a cryptographically secure random key
is generated using a suitable function (for example win32's RtlGenRandom as
described in
http://blogs.msdn.com/michael_howard/archive/2005/01/14/353379.aspx
otherwise the code defaults to cross-platform albeit less secure mechanism
using rand
*/
static void randomize_key(unsigned char* key,int key_data_len)
{
int randomized = 0;
int counter=0;
#ifdef WIN32
BOOLEAN res;
if (ares_fpSystemFunction036)
{
res = (*ares_fpSystemFunction036) (key, key_data_len);
if (res)
randomized = 1;
}
#else /* !WIN32 */
#ifdef RANDOM_FILE
FILE *f = fopen(RANDOM_FILE, "rb");
if(f) {
counter = aresx_uztosi(fread(key, 1, key_data_len, f));
fclose(f);
}
#endif
#endif /* WIN32 */
if ( !randomized ) {
for (;counter<key_data_len;counter++)
key[counter]=(unsigned char)(rand() % 256);
}
}
/* This is an internal function. Its contract is to read a line from
* a file into a dynamically allocated buffer, zeroing the trailing
* newline if there is one. The calling routine may call
* ares__read_line multiple times with the same buf and bufsize
* pointers; *buf will be reallocated and *bufsize adjusted as
* appropriate. The initial value of *buf should be NULL. After the
* calling routine is done reading lines, it should free *buf.
*/
int ares__read_line(FILE *fp, char **buf, size_t *bufsize)
{
char *newbuf;
size_t offset = 0;
size_t len;
if (*buf == NULL)
{
*buf = malloc(128);
if (!*buf)
return ARES_ENOMEM;
*bufsize = 128;
}
for (;;)
{
int bytestoread = aresx_uztosi(*bufsize - offset);
if (!fgets(*buf + offset, bytestoread, fp))
return (offset != 0) ? 0 : (ferror(fp)) ? ARES_EFILE : ARES_EOF;
len = offset + strlen(*buf + offset);
if ((*buf)[len - 1] == '\n')
{
(*buf)[len - 1] = 0;
break;
}
offset = len;
if(len < *bufsize - 1)
continue;
/* Allocate more space. */
newbuf = realloc(*buf, *bufsize * 2);
if (!newbuf)
return ARES_ENOMEM;
*buf = newbuf;
*bufsize *= 2;
}
return ARES_SUCCESS;
}
