// Validate a single UTF-8 character according to RFC 3629.
static int utf8proc_valid(const uint8_t *str, int str_len)
{
int length = utf8proc_charlen(str, str_len);
if (length <= 0)
return length;
switch (length) {
case 1:
if (str[0] == 0x00) {
// ASCII NUL is technically valid but rejected
// for security reasons.
return -length;
}
break;
case 2:
if (str[0] < 0xC2) {
// Overlong
return -length;
}
break;
case 3:
if (str[0] == 0xE0) {
if (str[1] < 0xA0) {
// Overlong
return -length;
}
}
else if (str[0] == 0xED) {
if (str[1] >= 0xA0) {
// Surrogate
return -length;
}
}
break;
case 4:
if (str[0] == 0xF0) {
if (str[1] < 0x90) {
// Overlong
return -length;
}
}
else if (str[0] >= 0xF4) {
if (str[0] > 0xF4 || str[1] >= 0x90) {
// Above 0x10FFFF
return -length;
}
}
break;
}
return length;
}
void utf8proc_detab(strbuf *ob, const uint8_t *line, size_t size)
{
static const uint8_t whitespace[] = " ";
size_t i = 0, tab = 0;
while (i < size) {
size_t org = i;
while (i < size && line[i] != '\t' && line[i] <= 0x80) {
i++; tab++;
}
if (i > org)
strbuf_put(ob, line + org, i - org);
if (i >= size)
break;
if (line[i] == '\t') {
int numspaces = 4 - (tab % 4);
strbuf_put(ob, whitespace, numspaces);
i += 1;
tab += numspaces;
} else {
int charlen = utf8proc_charlen(line + i, size - i);
if (charlen >= 0) {
strbuf_put(ob, line + i, charlen);
} else {
encode_unknown(ob);
charlen = -charlen;
}
i += charlen;
tab += 1;
}
}
}
int utf8proc_iterate(const uint8_t *str, int str_len, int32_t *dst)
{
int length;
int32_t uc = -1;
*dst = -1;
length = utf8proc_charlen(str, str_len);
if (length < 0)
return -1;
switch (length) {
case 1:
uc = str[0];
break;
case 2:
uc = ((str[0] & 0x1F) << 6) + (str[1] & 0x3F);
if (uc < 0x80) uc = -1;
break;
case 3:
uc = ((str[0] & 0x0F) << 12) + ((str[1] & 0x3F) << 6)
+ (str[2] & 0x3F);
if (uc < 0x800 || (uc >= 0xD800 && uc < 0xE000) ||
(uc >= 0xFDD0 && uc < 0xFDF0)) uc = -1;
break;
case 4:
uc = ((str[0] & 0x07) << 18) + ((str[1] & 0x3F) << 12)
+ ((str[2] & 0x3F) << 6) + (str[3] & 0x3F);
if (uc < 0x10000 || uc >= 0x110000) uc = -1;
break;
}
if (uc < 0 || ((uc & 0xFFFF) >= 0xFFFE))
return -1;
*dst = uc;
return length;
}
