Use mattermost v5 module (#1192)

vendor/github.com/mattermost/ldap/compare.go

@@ -0,0 +1,80 @@
+// File contains Compare functionality
+//
+// https://tools.ietf.org/html/rfc4511
+//
+// CompareRequest ::= [APPLICATION 14] SEQUENCE {
+//              entry           LDAPDN,
+//              ava             AttributeValueAssertion }
+//
+// AttributeValueAssertion ::= SEQUENCE {
+//              attributeDesc   AttributeDescription,
+//              assertionValue  AssertionValue }
+//
+// AttributeDescription ::= LDAPString
+//                         -- Constrained to <attributedescription>
+//                         -- [RFC4512]
+//
+// AttributeValue ::= OCTET STRING
+//
+
+package ldap
+
+import (
+	"fmt"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// CompareRequest represents an LDAP CompareRequest operation.
+type CompareRequest struct {
+	DN        string
+	Attribute string
+	Value     string
+}
+
+func (req *CompareRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationCompareRequest, nil, "Compare Request")
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.DN, "DN"))
+
+	ava := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "AttributeValueAssertion")
+	ava.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Attribute, "AttributeDesc"))
+	ava.AppendChild(ber.Encode(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Value, "AssertionValue"))
+
+	pkt.AppendChild(ava)
+
+	envelope.AppendChild(pkt)
+
+	return nil
+}
+
+// Compare checks to see if the attribute of the dn matches value. Returns true if it does otherwise
+// false with any error that occurs if any.
+func (l *Conn) Compare(dn, attribute, value string) (bool, error) {
+	msgCtx, err := l.doRequest(&CompareRequest{
+		DN:        dn,
+		Attribute: attribute,
+		Value:     value})
+	if err != nil {
+		return false, err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return false, err
+	}
+
+	if packet.Children[1].Tag == ApplicationCompareResponse {
+		err := GetLDAPError(packet)
+
+		switch {
+		case IsErrorWithCode(err, LDAPResultCompareTrue):
+			return true, nil
+		case IsErrorWithCode(err, LDAPResultCompareFalse):
+			return false, nil
+		default:
+			return false, err
+		}
+	}
+	return false, fmt.Errorf("unexpected Response: %d", packet.Children[1].Tag)
+}