1 files changed, 247 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/ldap/dn.go b/vendor/github.com/mattermost/ldap/dn.go
new file mode 100644
index 00000000..9d32e7fa
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/dn.go
@@ -0,0 +1,247 @@
+// File contains DN parsing functionality
+//
+// https://tools.ietf.org/html/rfc4514
+//
+//   distinguishedName = [ relativeDistinguishedName
+//         *( COMMA relativeDistinguishedName ) ]
+//     relativeDistinguishedName = attributeTypeAndValue
+//         *( PLUS attributeTypeAndValue )
+//     attributeTypeAndValue = attributeType EQUALS attributeValue
+//     attributeType = descr / numericoid
+//     attributeValue = string / hexstring
+//
+//     ; The following characters are to be escaped when they appear
+//     ; in the value to be encoded: ESC, one of <escaped>, leading
+//     ; SHARP or SPACE, trailing SPACE, and NULL.
+//     string =   [ ( leadchar / pair ) [ *( stringchar / pair )
+//        ( trailchar / pair ) ] ]
+//
+//     leadchar = LUTF1 / UTFMB
+//     LUTF1 = %x01-1F / %x21 / %x24-2A / %x2D-3A /
+//        %x3D / %x3F-5B / %x5D-7F
+//
+//     trailchar  = TUTF1 / UTFMB
+//     TUTF1 = %x01-1F / %x21 / %x23-2A / %x2D-3A /
+//        %x3D / %x3F-5B / %x5D-7F
+//
+//     stringchar = SUTF1 / UTFMB
+//     SUTF1 = %x01-21 / %x23-2A / %x2D-3A /
+//        %x3D / %x3F-5B / %x5D-7F
+//
+//     pair = ESC ( ESC / special / hexpair )
+//     special = escaped / SPACE / SHARP / EQUALS
+//     escaped = DQUOTE / PLUS / COMMA / SEMI / LANGLE / RANGLE
+//     hexstring = SHARP 1*hexpair
+//     hexpair = HEX HEX
+//
+//  where the productions <descr>, <numericoid>, <COMMA>, <DQUOTE>,
+//  <EQUALS>, <ESC>, <HEX>, <LANGLE>, <NULL>, <PLUS>, <RANGLE>, <SEMI>,
+//  <SPACE>, <SHARP>, and <UTFMB> are defined in [RFC4512].
+//
+
+package ldap
+
+import (
+	"bytes"
+	enchex "encoding/hex"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/go-asn1-ber/asn1-ber"
+)
+
+// AttributeTypeAndValue represents an attributeTypeAndValue from https://tools.ietf.org/html/rfc4514
+type AttributeTypeAndValue struct {
+	// Type is the attribute type
+	Type string
+	// Value is the attribute value
+	Value string
+}
+
+// RelativeDN represents a relativeDistinguishedName from https://tools.ietf.org/html/rfc4514
+type RelativeDN struct {
+	Attributes []*AttributeTypeAndValue
+}
+
+// DN represents a distinguishedName from https://tools.ietf.org/html/rfc4514
+type DN struct {
+	RDNs []*RelativeDN
+}
+
+// ParseDN returns a distinguishedName or an error
+func ParseDN(str string) (*DN, error) {
+	dn := new(DN)
+	dn.RDNs = make([]*RelativeDN, 0)
+	rdn := new(RelativeDN)
+	rdn.Attributes = make([]*AttributeTypeAndValue, 0)
+	buffer := bytes.Buffer{}
+	attribute := new(AttributeTypeAndValue)
+	escaping := false
+
+	unescapedTrailingSpaces := 0
+	stringFromBuffer := func() string {
+		s := buffer.String()
+		s = s[0 : len(s)-unescapedTrailingSpaces]
+		buffer.Reset()
+		unescapedTrailingSpaces = 0
+		return s
+	}
+
+	for i := 0; i < len(str); i++ {
+		char := str[i]
+		switch {
+		case escaping:
+			unescapedTrailingSpaces = 0
+			escaping = false
+			switch char {
+			case ' ', '"', '#', '+', ',', ';', '<', '=', '>', '\\':
+				buffer.WriteByte(char)
+				continue
+			}
+			// Not a special character, assume hex encoded octet
+			if len(str) == i+1 {
+				return nil, errors.New("got corrupted escaped character")
+			}
+
+			dst := []byte{0}
+			n, err := enchex.Decode([]byte(dst), []byte(str[i:i+2]))
+			if err != nil {
+				return nil, fmt.Errorf("failed to decode escaped character: %s", err)
+			} else if n != 1 {
+				return nil, fmt.Errorf("expected 1 byte when un-escaping, got %d", n)
+			}
+			buffer.WriteByte(dst[0])
+			i++
+		case char == '\\':
+			unescapedTrailingSpaces = 0
+			escaping = true
+		case char == '=':
+			attribute.Type = stringFromBuffer()
+			// Special case: If the first character in the value is # the
+			// following data is BER encoded so we can just fast forward
+			// and decode.
+			if len(str) > i+1 && str[i+1] == '#' {
+				i += 2
+				index := strings.IndexAny(str[i:], ",+")
+				data := str
+				if index > 0 {
+					data = str[i : i+index]
+				} else {
+					data = str[i:]
+				}
+				rawBER, err := enchex.DecodeString(data)
+				if err != nil {
+					return nil, fmt.Errorf("failed to decode BER encoding: %s", err)
+				}
+				packet, err := ber.DecodePacketErr(rawBER)
+				if err != nil {
+					return nil, fmt.Errorf("failed to decode BER packet: %s", err)
+				}
+				buffer.WriteString(packet.Data.String())
+				i += len(data) - 1
+			}
+		case char == ',' || char == '+':
+			// We're done with this RDN or value, push it
+			if len(attribute.Type) == 0 {
+				return nil, errors.New("incomplete type, value pair")
+			}
+			attribute.Value = stringFromBuffer()
+			rdn.Attributes = append(rdn.Attributes, attribute)
+			attribute = new(AttributeTypeAndValue)
+			if char == ',' {
+				dn.RDNs = append(dn.RDNs, rdn)
+				rdn = new(RelativeDN)
+				rdn.Attributes = make([]*AttributeTypeAndValue, 0)
+			}
+		case char == ' ' && buffer.Len() == 0:
+			// ignore unescaped leading spaces
+			continue
+		default:
+			if char == ' ' {
+				// Track unescaped spaces in case they are trailing and we need to remove them
+				unescapedTrailingSpaces++
+			} else {
+				// Reset if we see a non-space char
+				unescapedTrailingSpaces = 0
+			}
+			buffer.WriteByte(char)
+		}
+	}
+	if buffer.Len() > 0 {
+		if len(attribute.Type) == 0 {
+			return nil, errors.New("DN ended with incomplete type, value pair")
+		}
+		attribute.Value = stringFromBuffer()
+		rdn.Attributes = append(rdn.Attributes, attribute)
+		dn.RDNs = append(dn.RDNs, rdn)
+	}
+	return dn, nil
+}
+
+// Equal returns true if the DNs are equal as defined by rfc4517 4.2.15 (distinguishedNameMatch).
+// Returns true if they have the same number of relative distinguished names
+// and corresponding relative distinguished names (by position) are the same.
+func (d *DN) Equal(other *DN) bool {
+	if len(d.RDNs) != len(other.RDNs) {
+		return false
+	}
+	for i := range d.RDNs {
+		if !d.RDNs[i].Equal(other.RDNs[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// AncestorOf returns true if the other DN consists of at least one RDN followed by all the RDNs of the current DN.
+// "ou=widgets,o=acme.com" is an ancestor of "ou=sprockets,ou=widgets,o=acme.com"
+// "ou=widgets,o=acme.com" is not an ancestor of "ou=sprockets,ou=widgets,o=foo.com"
+// "ou=widgets,o=acme.com" is not an ancestor of "ou=widgets,o=acme.com"
+func (d *DN) AncestorOf(other *DN) bool {
+	if len(d.RDNs) >= len(other.RDNs) {
+		return false
+	}
+	// Take the last `len(d.RDNs)` RDNs from the other DN to compare against
+	otherRDNs := other.RDNs[len(other.RDNs)-len(d.RDNs):]
+	for i := range d.RDNs {
+		if !d.RDNs[i].Equal(otherRDNs[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if the RelativeDNs are equal as defined by rfc4517 4.2.15 (distinguishedNameMatch).
+// Relative distinguished names are the same if and only if they have the same number of AttributeTypeAndValues
+// and each attribute of the first RDN is the same as the attribute of the second RDN with the same attribute type.
+// The order of attributes is not significant.
+// Case of attribute types is not significant.
+func (r *RelativeDN) Equal(other *RelativeDN) bool {
+	if len(r.Attributes) != len(other.Attributes) {
+		return false
+	}
+	return r.hasAllAttributes(other.Attributes) && other.hasAllAttributes(r.Attributes)
+}
+
+func (r *RelativeDN) hasAllAttributes(attrs []*AttributeTypeAndValue) bool {
+	for _, attr := range attrs {
+		found := false
+		for _, myattr := range r.Attributes {
+			if myattr.Equal(attr) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if the AttributeTypeAndValue is equivalent to the specified AttributeTypeAndValue
+// Case of the attribute type is not significant
+func (a *AttributeTypeAndValue) Equal(other *AttributeTypeAndValue) bool {
+	return strings.EqualFold(a.Type, other.Type) && a.Value == other.Value
+}