1 files changed, 199 insertions, 0 deletions
diff --git a/goldap/bytes.go b/goldap/bytes.go
new file mode 100644
index 0000000..92c63a2
--- /dev/null
+++ b/goldap/bytes.go
@@ -0,0 +1,199 @@
+package message
+
+import (
+	"fmt"
+)
+
+type Bytes struct {
+	offset int
+	bytes  []byte
+}
+
+func (bytes *Bytes) getBytes() []byte {
+	return bytes.bytes
+}
+func NewBytes(offset int, bytes []byte) (ret *Bytes) {
+	return &Bytes{offset: offset, bytes: bytes}
+}
+
+func (bytes Bytes) Debug() {
+	fmt.Printf("Offset: %d, Bytes: %+v\n", bytes.offset, bytes.bytes)
+}
+
+// Return a string with the hex dump of the bytes around the current offset
+// The current offset byte is put in brackets
+// Example: 0x01, [0x02], 0x03
+func (bytes *Bytes) DumpCurrentBytes() (ret string) {
+	var strings [3]string
+	for i := -1; i <= 1; i++ {
+		if bytes.offset+i >= 0 && bytes.offset+i < len(bytes.bytes) {
+			strings[i+1] = fmt.Sprintf("%#x", bytes.bytes[bytes.offset+i])
+		}
+	}
+	ret = fmt.Sprintf("%s, [%s], %s", strings[0], strings[1], strings[2])
+	return
+}
+
+func (bytes *Bytes) HasMoreData() bool {
+	return bytes.offset < len(bytes.bytes)
+}
+
+func (bytes *Bytes) ParseTagAndLength() (ret TagAndLength, err error) {
+	var offset int
+	ret, offset, err = ParseTagAndLength(bytes.bytes, bytes.offset)
+	if err != nil {
+		err = LdapError{fmt.Sprintf("ParseTagAndLength: %s", err.Error())}
+		return
+	} else {
+		bytes.offset = offset
+	}
+	return
+}
+
+func (bytes *Bytes) ReadSubBytes(class int, tag int, callback func(bytes *Bytes) error) (err error) {
+	// Check tag
+	tagAndLength, err := bytes.ParseTagAndLength()
+	if err != nil {
+		return LdapError{fmt.Sprintf("ReadSubBytes:\n%s", err.Error())}
+	}
+	err = tagAndLength.Expect(class, tag, isCompound)
+	if err != nil {
+		return LdapError{fmt.Sprintf("ReadSubBytes:\n%s", err.Error())}
+	}
+
+	start := bytes.offset
+	end := bytes.offset + tagAndLength.Length
+
+	// Check we got enough bytes to process
+	if end > len(bytes.bytes) {
+		return LdapError{fmt.Sprintf("ReadSubBytes: data truncated: expecting %d bytes at offset %d", tagAndLength.Length, bytes.offset)}
+	}
+	// Process sub-bytes
+	subBytes := Bytes{offset: 0, bytes: bytes.bytes[start:end]}
+	err = callback(&subBytes)
+	if err != nil {
+		bytes.offset += subBytes.offset
+		err = LdapError{fmt.Sprintf("ReadSubBytes:\n%s", err.Error())}
+		return
+	}
+	// Check we got no more bytes to process
+	if subBytes.HasMoreData() {
+		return LdapError{fmt.Sprintf("ReadSubBytes: data too long: %d more bytes to read at offset %d", end-bytes.offset, bytes.offset)}
+	}
+	// Move offset
+	bytes.offset = end
+	return
+}
+
+func SizeSubBytes(tag int, callback func() int) (size int) {
+	size = callback()
+	size += sizeTagAndLength(tag, size)
+	return
+}
+
+func (bytes *Bytes) WritePrimitiveSubBytes(class int, tag int, value interface{}) (size int) {
+	switch value.(type) {
+	case BOOLEAN:
+		size = writeBool(bytes, bool(value.(BOOLEAN)))
+	case INTEGER:
+		size = writeInt32(bytes, int32(value.(INTEGER)))
+	case ENUMERATED:
+		size = writeInt32(bytes, int32(value.(ENUMERATED)))
+	case OCTETSTRING:
+		size = writeOctetString(bytes, []byte(string(value.(OCTETSTRING))))
+	default:
+		panic(fmt.Sprintf("WritePrimitiveSubBytes: invalid value type %v", value))
+	}
+	size += bytes.WriteTagAndLength(class, isNotCompound, tag, size)
+	return
+}
+
+func (bytes *Bytes) WriteTagAndLength(class int, compound bool, tag int, length int) int {
+	return writeTagAndLength(bytes, TagAndLength{Class: class, IsCompound: compound, Tag: tag, Length: length})
+}
+
+func (bytes *Bytes) writeString(s string) (size int) {
+	size = len(s)
+	start := bytes.offset - size
+	if start < 0 {
+		panic("Not enough space for string")
+	}
+	copy(bytes.bytes[start:], s)
+	bytes.offset = start
+	return
+}
+
+func (bytes *Bytes) writeBytes(b []byte) (size int) {
+	size = len(b)
+	start := bytes.offset - size
+	if start < 0 {
+		panic("Not enough space for bytes")
+	}
+	copy(bytes.bytes[start:], b)
+	bytes.offset = start
+	return
+}
+
+//
+// Parse tag, length and read the a primitive value
+// Supported types are:
+// - boolean
+// - integer (parsed as int32)
+// - enumerated (parsed as int32)
+// - UTF8 string
+// - Octet string
+//
+// Parameters:
+// - class: the expected class value(classUniversal, classApplication, classContextSpecific)
+// - tag: the expected tag value
+// - typeTag: the real primitive type to parse (tagBoolean, tagInteger, tagEnym, tagUTF8String, tagOctetString)
+//
+func (bytes *Bytes) ReadPrimitiveSubBytes(class int, tag int, typeTag int) (value interface{}, err error) {
+	// Check tag
+	tagAndLength, err := bytes.ParseTagAndLength()
+	if err != nil {
+		err = LdapError{fmt.Sprintf("ReadPrimitiveSubBytes:\n%s", err.Error())}
+		return
+	}
+	err = tagAndLength.Expect(class, tag, isNotCompound)
+	if err != nil {
+		err = LdapError{fmt.Sprintf("ReadPrimitiveSubBytes:\n%s", err.Error())}
+		return
+	}
+
+	start := bytes.offset
+	end := bytes.offset + tagAndLength.Length
+
+	// Check we got enough bytes to process
+	if end > len(bytes.bytes) {
+		// err = LdapError{fmt.Sprintf("ReadPrimitiveSubBytes: data truncated: expecting %d bytes at offset %d but only %d bytes are remaining (start: %d, length: %d, end: %d, len(b): %d, bytes: %#+v)", tagAndLength.Length, *b.offset, len(b.bytes)-start, start, tagAndLength.Length, end, len(b.bytes), b.bytes)}
+		err = LdapError{fmt.Sprintf("ReadPrimitiveSubBytes: data truncated: expecting %d bytes at offset %d but only %d bytes are remaining", tagAndLength.Length, bytes.offset, len(bytes.bytes)-start)}
+		return
+	}
+	// Process sub-bytes
+	subBytes := bytes.bytes[start:end]
+	switch typeTag {
+	case tagBoolean:
+		value, err = parseBool(subBytes)
+	case tagInteger:
+		value, err = parseInt32(subBytes)
+	case tagEnum:
+		value, err = parseInt32(subBytes)
+	case tagOctetString:
+		value, err = parseOctetString(subBytes)
+	default:
+		err = LdapError{fmt.Sprintf("ReadPrimitiveSubBytes: invalid type tag value %d", typeTag)}
+		return
+	}
+	if err != nil {
+		err = LdapError{fmt.Sprintf("ReadPrimitiveSubBytes:\n%s", err.Error())}
+		return
+	}
+	// Move offset
+	bytes.offset = end
+	return
+}
+
+func (bytes *Bytes) Bytes() []byte {
+	return bytes.bytes
+}