#include "asn1_get.h"
asn1_error_code
asn1_get_tag_2(asn1buf *buf, taginfo *t)
{
asn1_error_code retval;
if (buf == NULL || buf->base == NULL ||
buf->bound - buf->next + 1 <= 0) {
t->tagnum = ASN1_TAGNUM_CEILING;
t->asn1class = UNIVERSAL;
t->construction = PRIMITIVE;
t->length = 0;
t->indef = 0;
return 0;
}
{
asn1_tagnum tn=0;
asn1_octet o;
#define ASN1_CLASS_MASK 0xC0
#define ASN1_CONSTRUCTION_MASK 0x20
#define ASN1_TAG_NUMBER_MASK 0x1F
retval = asn1buf_remove_octet(buf,&o);
if (retval)
return retval;
t->asn1class = (asn1_class)(o&ASN1_CLASS_MASK);
t->construction = (asn1_construction)(o&ASN1_CONSTRUCTION_MASK);
if ((o&ASN1_TAG_NUMBER_MASK) != ASN1_TAG_NUMBER_MASK){
t->tagnum = (asn1_tagnum)(o&ASN1_TAG_NUMBER_MASK);
} else {
do {
retval = asn1buf_remove_octet(buf,&o);
if (retval) return retval;
tn = (tn<<7) + (asn1_tagnum)(o&0x7F);
}while(tn&0x80);
t->tagnum = tn;
}
}
{
asn1_octet o;
t->indef = 0;
retval = asn1buf_remove_octet(buf,&o);
if (retval) return retval;
if ((o&0x80) == 0) {
t->length = (int)(o&0x7F);
} else {
int num;
int len=0;
for (num = (int)(o&0x7F); num>0; num--) {
retval = asn1buf_remove_octet(buf,&o);
if(retval) return retval;
len = (len<<8) + (int)o;
}
if (len < 0)
return ASN1_OVERRUN;
if (!len)
t->indef = 1;
t->length = len;
}
}
if (t->indef && t->construction != CONSTRUCTED)
return ASN1_MISMATCH_INDEF;
return 0;
}
asn1_error_code asn1_get_sequence(asn1buf *buf, unsigned int *retlen, int *indef)
{
taginfo t;
asn1_error_code retval;
retval = asn1_get_tag_2(buf, &t);
if (retval)
return retval;
if (t.asn1class != UNIVERSAL || t.construction != CONSTRUCTED ||
t.tagnum != ASN1_SEQUENCE)
return ASN1_BAD_ID;
if (retlen)
*retlen = t.length;
if (indef)
*indef = t.indef;
return 0;
}