static size_t decode_len(const uint8_t **ptr, const uint8_t *end)
{
const uint8_t *tmp = *ptr;
size_t ret;
if ( ber_len_form_short(*tmp) ) {
ret = ber_len_short(*tmp);
tmp++;
}else{
size_t i, l;
l = ber_len_short(*tmp);
if ( l > 4 || tmp + l > end ) {
*ptr = end;
return 1;
}
tmp++;
for(ret = i = 0; i < l; i++, tmp++) {
ret <<= 8;
ret |= *tmp;
}
}
*ptr = tmp;
return ret;
}
static const uint8_t *do_decode_tag(struct gber_tag *tag,
const uint8_t *ptr, size_t len)
{
const uint8_t *end = ptr + len;
if ( len < 2 ) {
printf("block too small\n");
return NULL;
}
tag->ber_id = *(ptr++);
tag->ber_tag = tag->ber_id;
if ( (tag->ber_id & 0x1f) == 0x1f ) {
if ( (*ptr & 0x80) ) {
printf("bad id\n");
return NULL;
}
tag->ber_tag <<= 8;
tag->ber_tag |= *(ptr++);
if ( ptr >= end ) {
printf("tag too big\n");
return NULL;
}
}
if ( ber_len_form_short(*ptr) ) {
tag->ber_len = ber_len_short(*ptr);
ptr++;
}else{
unsigned int i;
uint8_t ll;
ll = ber_len_short(*(ptr++));
if ( ptr + ll > end || ll > 4 ) {
printf("tag past end\n");
return NULL;
}
for(tag->ber_len = 0, i = 0; i < ll; i++, ptr++) {
tag->ber_len <<= 8;
tag->ber_len |= *ptr;
}
}
return ptr;
}
static const uint8_t *do_decode_tag(struct gber_tag *tag,
const uint8_t *ptr, size_t len)
{
const uint8_t *end = ptr + len;
if ( len < 2 )
return NULL;
tag->ber_id = *(ptr++);
tag->ber_tag = tag->ber_id;
if ( (tag->ber_id & 0x1f) == 0x1f ) {
if ( (*ptr & 0x80) )
return NULL;
tag->ber_tag <<= 8;
tag->ber_tag |= *(ptr++);
if ( ptr >= end )
return NULL;
}
if ( ber_len_form_short(*ptr) ) {
tag->ber_len = ber_len_short(*ptr);
ptr++;
}else{
unsigned int i;
uint8_t ll;
ll = ber_len_short(*(ptr++));
if ( ptr + ll > end || ll > 4 )
return NULL;
for(tag->ber_len = 0, i = 0; i < ll; i++, ptr++) {
tag->ber_len <<= 8;
tag->ber_len |= *ptr;
}
}
return ptr;
}
void ber_dump(const uint8_t *buf, size_t len, unsigned int depth)
{
const uint8_t *end = buf + len;
uint32_t clen, num, i;
uint8_t idb;
#if 0
const char * const clsname[]={
"universal",
"application",
"context-specific",
"private",
};
#endif
again:
if ( buf >= end )
return;
idb = *buf;
num = ber_id_octet_tag(*buf);
buf++;
/* FIXME: if ( tag == 0x1f ) get rest of type... */
if ( num >= 0x1f ) {
for(num = 0, i = 0; buf < end; i++) {
num <<= 7;
num |= *buf & 0x7f;
buf++;
if ( !(*buf & 0x80) )
break;
}
}
printf("%*c.tag = %u (0x%x)\n", depth, ' ', num, num);
if ( buf >= end )
return;
if ( ber_len_form_short(*buf) ) {
clen = ber_len_short(*buf);
buf++;
}else{
uint32_t l;
l = ber_len_short(*buf);
if ( l > 4 || buf + l > end )
return;
buf++;
for(clen = i = 0; i < l; i++, buf++) {
clen <<= 8;
clen |= *buf;
}
}
if ( buf + clen > end )
return;
printf("%*c.len = %zu (0x%zx)",
depth, ' ', len, len);
if ( ber_id_octet_constructed(idb) ) {
printf(" {\n");
ber_dump(buf, clen, depth + 2);
printf("%*c}\n", depth, ' ');
}else{
printf("\n");
hex_dump(buf, clen, 16, depth);
}
buf += clen;
goto again;
}