+++ /dev/null
-// Copyright 2017 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package cryptobyte implements building and parsing of byte strings for
-// DER-encoded ASN.1 and TLS messages. See the examples for the Builder and
-// String types to get started.
-package cryptobyte // import "golang.org/x/crypto/cryptobyte"
-
-// String represents a string of bytes. It provides methods for parsing
-// fixed-length and length-prefixed values from it.
-type String []byte
-
-// read advances a String by n bytes and returns them. If less than n bytes
-// remain, it returns nil.
-func (s *String) read(n int) []byte {
- if len(*s) < n {
- return nil
- }
- v := (*s)[:n]
- *s = (*s)[n:]
- return v
-}
-
-// Skip advances the String by n byte and reports whether it was successful.
-func (s *String) Skip(n int) bool {
- return s.read(n) != nil
-}
-
-// ReadUint8 decodes an 8-bit value into out and advances over it. It
-// returns true on success and false on error.
-func (s *String) ReadUint8(out *uint8) bool {
- v := s.read(1)
- if v == nil {
- return false
- }
- *out = uint8(v[0])
- return true
-}
-
-// ReadUint16 decodes a big-endian, 16-bit value into out and advances over it.
-// It returns true on success and false on error.
-func (s *String) ReadUint16(out *uint16) bool {
- v := s.read(2)
- if v == nil {
- return false
- }
- *out = uint16(v[0])<<8 | uint16(v[1])
- return true
-}
-
-// ReadUint24 decodes a big-endian, 24-bit value into out and advances over it.
-// It returns true on success and false on error.
-func (s *String) ReadUint24(out *uint32) bool {
- v := s.read(3)
- if v == nil {
- return false
- }
- *out = uint32(v[0])<<16 | uint32(v[1])<<8 | uint32(v[2])
- return true
-}
-
-// ReadUint32 decodes a big-endian, 32-bit value into out and advances over it.
-// It returns true on success and false on error.
-func (s *String) ReadUint32(out *uint32) bool {
- v := s.read(4)
- if v == nil {
- return false
- }
- *out = uint32(v[0])<<24 | uint32(v[1])<<16 | uint32(v[2])<<8 | uint32(v[3])
- return true
-}
-
-func (s *String) readUnsigned(out *uint32, length int) bool {
- v := s.read(length)
- if v == nil {
- return false
- }
- var result uint32
- for i := 0; i < length; i++ {
- result <<= 8
- result |= uint32(v[i])
- }
- *out = result
- return true
-}
-
-func (s *String) readLengthPrefixed(lenLen int, outChild *String) bool {
- lenBytes := s.read(lenLen)
- if lenBytes == nil {
- return false
- }
- var length uint32
- for _, b := range lenBytes {
- length = length << 8
- length = length | uint32(b)
- }
- if int(length) < 0 {
- // This currently cannot overflow because we read uint24 at most, but check
- // anyway in case that changes in the future.
- return false
- }
- v := s.read(int(length))
- if v == nil {
- return false
- }
- *outChild = v
- return true
-}
-
-// ReadUint8LengthPrefixed reads the content of an 8-bit length-prefixed value
-// into out and advances over it. It returns true on success and false on
-// error.
-func (s *String) ReadUint8LengthPrefixed(out *String) bool {
- return s.readLengthPrefixed(1, out)
-}
-
-// ReadUint16LengthPrefixed reads the content of a big-endian, 16-bit
-// length-prefixed value into out and advances over it. It returns true on
-// success and false on error.
-func (s *String) ReadUint16LengthPrefixed(out *String) bool {
- return s.readLengthPrefixed(2, out)
-}
-
-// ReadUint24LengthPrefixed reads the content of a big-endian, 24-bit
-// length-prefixed value into out and advances over it. It returns true on
-// success and false on error.
-func (s *String) ReadUint24LengthPrefixed(out *String) bool {
- return s.readLengthPrefixed(3, out)
-}
-
-// ReadBytes reads n bytes into out and advances over them. It returns true on
-// success and false and error.
-func (s *String) ReadBytes(out *[]byte, n int) bool {
- v := s.read(n)
- if v == nil {
- return false
- }
- *out = v
- return true
-}
-
-// CopyBytes copies len(out) bytes into out and advances over them. It returns
-// true on success and false on error.
-func (s *String) CopyBytes(out []byte) bool {
- n := len(out)
- v := s.read(n)
- if v == nil {
- return false
- }
- return copy(out, v) == n
-}
-
-// Empty reports whether the string does not contain any bytes.
-func (s String) Empty() bool {
- return len(s) == 0
-}
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