1package ldap
2
3import (
4	"fmt"
5
6	ber "github.com/go-asn1-ber/asn1-ber"
7)
8
9// CompareRequest represents an LDAP CompareRequest operation.
10type CompareRequest struct {
11	DN        string
12	Attribute string
13	Value     string
14}
15
16func (req *CompareRequest) appendTo(envelope *ber.Packet) error {
17	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationCompareRequest, nil, "Compare Request")
18	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.DN, "DN"))
19
20	ava := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "AttributeValueAssertion")
21	ava.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Attribute, "AttributeDesc"))
22	ava.AppendChild(ber.Encode(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Value, "AssertionValue"))
23
24	pkt.AppendChild(ava)
25
26	envelope.AppendChild(pkt)
27
28	return nil
29}
30
31// Compare checks to see if the attribute of the dn matches value. Returns true if it does otherwise
32// false with any error that occurs if any.
33func (l *Conn) Compare(dn, attribute, value string) (bool, error) {
34	msgCtx, err := l.doRequest(&CompareRequest{
35		DN:        dn,
36		Attribute: attribute,
37		Value:     value})
38	if err != nil {
39		return false, err
40	}
41	defer l.finishMessage(msgCtx)
42
43	packet, err := l.readPacket(msgCtx)
44	if err != nil {
45		return false, err
46	}
47
48	if packet.Children[1].Tag == ApplicationCompareResponse {
49		err := GetLDAPError(packet)
50
51		switch {
52		case IsErrorWithCode(err, LDAPResultCompareTrue):
53			return true, nil
54		case IsErrorWithCode(err, LDAPResultCompareFalse):
55			return false, nil
56		default:
57			return false, err
58		}
59	}
60	return false, fmt.Errorf("unexpected Response: %d", packet.Children[1].Tag)
61}
62