static unsigned char
nibble(char c)
{
c = PORT_Tolower(c);
return (c >= '0' && c <= '9') ? c - '0' : (c >=
'a' &&
c <=
'f')
? c - 'a' + 10
: -1;
}
SECStatus
SECU_SECItemHexStringToBinary(SECItem* srcdest)
{
int i;
if (!srcdest) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (srcdest->len < 4 || (srcdest->len % 2) ) {
/* too short to convert, or even number of characters */
PORT_SetError(SEC_ERROR_BAD_DATA);
return SECFailure;
}
if (PORT_Strncasecmp((const char*)srcdest->data, "0x", 2)) {
/* wrong prefix */
PORT_SetError(SEC_ERROR_BAD_DATA);
return SECFailure;
}
/* 1st pass to check for hex characters */
for (i=2; i<srcdest->len; i++) {
char c = PORT_Tolower(srcdest->data[i]);
if (! ( ( c >= '0' && c <= '9') ||
( c >= 'a' && c <= 'f')
) ) {
PORT_SetError(SEC_ERROR_BAD_DATA);
return SECFailure;
}
}
/* 2nd pass to convert */
for (i=2; i<srcdest->len; i+=2) {
srcdest->data[(i-2)/2] = (nibble(srcdest->data[i]) << 4) +
nibble(srcdest->data[i+1]);
}
/* adjust length */
srcdest->len -= 2;
srcdest->len /= 2;
return SECSuccess;
}
