/*
utils.c -- gathering of some stupid small functions
Copyright (C) 1999-2005 Ivo Timmermans
- 2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2014 Guus Sliepen <guus@tinc-vpn.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
static const char hexadecimals[] = "0123456789ABCDEF";
static int charhex2bin(char c) {
- if(isdigit(c))
+ if(isdigit(c)) {
return c - '0';
- else
+ } else {
return toupper(c) - 'A' + 10;
+ }
}
bool hex2bin(char *src, char *dst, int length) {
for(int i = 0; i < length; i++) {
- if(!isxdigit(src[i * 2]) || !isxdigit(src[i * 2 + 1]))
+ if(!isxdigit(src[i * 2]) || !isxdigit(src[i * 2 + 1])) {
return false;
+ }
+
dst[i] = charhex2bin(src[i * 2]) * 16 + charhex2bin(src[i * 2 + 1]);
}
+
return true;
}
void bin2hex(char *src, char *dst, int length) {
int i;
+
for(i = length - 1; i >= 0; i--) {
dst[i * 2 + 1] = hexadecimals[(unsigned char) src[i] & 15];
dst[i * 2] = hexadecimals[(unsigned char) src[i] >> 4];
ptr = buf + sprintf(buf, "(%d) ", err);
- if (!FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
- NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL), ptr, sizeof(buf) - (ptr - buf), NULL)) {
+ if(!FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+ NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL), ptr, sizeof(buf) - (ptr - buf), NULL)) {
strcpy(ptr, "(unable to format errormessage)");
};
- if((ptr = strchr(buf, '\r')))
+ if((ptr = strchr(buf, '\r'))) {
*ptr = '\0';
+ }
return buf;
}
unsigned int bitfield_to_int(const void *bitfield, size_t size) {
unsigned int value = 0;
- if(size > sizeof value)
- size = sizeof value;
+
+ if(size > sizeof(value)) {
+ size = sizeof(value);
+ }
+
memcpy(&value, bitfield, size);
return value;
}
+
+/**
+ * As memcmp(), but constant-time.
+ * Returns 0 when data is equal, non-zero otherwise.
+ */
+int memcmp_constant_time(const void *a, const void *b, size_t size) {
+ const uint8_t *a1 = a, *b1 = b;
+ int ret = 0;
+ size_t i;
+
+ for(i = 0; i < size; i++) {
+ ret |= *a1++ ^ *b1++;
+ }
+
+ return ret;
+}