removed uber zap from vendor and switched to dep from glide (#6)

This commit is contained in:
Steve Brunton
2017-11-29 22:48:49 -05:00
committed by GitHub
parent be3ca4608c
commit c37abb638f
514 changed files with 25671 additions and 44097 deletions

View File

@@ -5,40 +5,30 @@
package cryptobyte
import (
"encoding/asn1"
encoding_asn1 "encoding/asn1"
"fmt"
"math/big"
"reflect"
"time"
"golang.org/x/crypto/cryptobyte/asn1"
)
// This file contains ASN.1-related methods for String and Builder.
// Tag represents an ASN.1 tag number and class (together also referred to as
// identifier octets). Methods in this package only support the low-tag-number
// form, i.e. a single identifier octet with bits 7-8 encoding the class and
// bits 1-6 encoding the tag number.
type Tag uint8
// Contructed returns t with the context-specific class bit set.
func (t Tag) ContextSpecific() Tag { return t | 0x80 }
// Contructed returns t with the constructed class bit set.
func (t Tag) Constructed() Tag { return t | 0x20 }
// Builder
// AddASN1Int64 appends a DER-encoded ASN.1 INTEGER.
func (b *Builder) AddASN1Int64(v int64) {
b.addASN1Signed(asn1.TagInteger, v)
b.addASN1Signed(asn1.INTEGER, v)
}
// AddASN1Enum appends a DER-encoded ASN.1 ENUMERATION.
func (b *Builder) AddASN1Enum(v int64) {
b.addASN1Signed(asn1.TagEnum, v)
b.addASN1Signed(asn1.ENUM, v)
}
func (b *Builder) addASN1Signed(tag Tag, v int64) {
func (b *Builder) addASN1Signed(tag asn1.Tag, v int64) {
b.AddASN1(tag, func(c *Builder) {
length := 1
for i := v; i >= 0x80 || i < -0x80; i >>= 8 {
@@ -54,7 +44,7 @@ func (b *Builder) addASN1Signed(tag Tag, v int64) {
// AddASN1Uint64 appends a DER-encoded ASN.1 INTEGER.
func (b *Builder) AddASN1Uint64(v uint64) {
b.AddASN1(asn1.TagInteger, func(c *Builder) {
b.AddASN1(asn1.INTEGER, func(c *Builder) {
length := 1
for i := v; i >= 0x80; i >>= 8 {
length++
@@ -73,7 +63,7 @@ func (b *Builder) AddASN1BigInt(n *big.Int) {
return
}
b.AddASN1(asn1.TagInteger, func(c *Builder) {
b.AddASN1(asn1.INTEGER, func(c *Builder) {
if n.Sign() < 0 {
// A negative number has to be converted to two's-complement form. So we
// invert and subtract 1. If the most-significant-bit isn't set then
@@ -103,7 +93,7 @@ func (b *Builder) AddASN1BigInt(n *big.Int) {
// AddASN1OctetString appends a DER-encoded ASN.1 OCTET STRING.
func (b *Builder) AddASN1OctetString(bytes []byte) {
b.AddASN1(asn1.TagOctetString, func(c *Builder) {
b.AddASN1(asn1.OCTET_STRING, func(c *Builder) {
c.AddBytes(bytes)
})
}
@@ -116,27 +106,97 @@ func (b *Builder) AddASN1GeneralizedTime(t time.Time) {
b.err = fmt.Errorf("cryptobyte: cannot represent %v as a GeneralizedTime", t)
return
}
b.AddASN1(asn1.TagGeneralizedTime, func(c *Builder) {
b.AddASN1(asn1.GeneralizedTime, func(c *Builder) {
c.AddBytes([]byte(t.Format(generalizedTimeFormatStr)))
})
}
// AddASN1BitString appends a DER-encoded ASN.1 BIT STRING.
func (b *Builder) AddASN1BitString(s asn1.BitString) {
// TODO(martinkr): Implement.
b.MarshalASN1(s)
// AddASN1BitString appends a DER-encoded ASN.1 BIT STRING. This does not
// support BIT STRINGs that are not a whole number of bytes.
func (b *Builder) AddASN1BitString(data []byte) {
b.AddASN1(asn1.BIT_STRING, func(b *Builder) {
b.AddUint8(0)
b.AddBytes(data)
})
}
// MarshalASN1 calls asn1.Marshal on its input and appends the result if
func (b *Builder) addBase128Int(n int64) {
var length int
if n == 0 {
length = 1
} else {
for i := n; i > 0; i >>= 7 {
length++
}
}
for i := length - 1; i >= 0; i-- {
o := byte(n >> uint(i*7))
o &= 0x7f
if i != 0 {
o |= 0x80
}
b.add(o)
}
}
func isValidOID(oid encoding_asn1.ObjectIdentifier) bool {
if len(oid) < 2 {
return false
}
if oid[0] > 2 || (oid[0] <= 1 && oid[1] >= 40) {
return false
}
for _, v := range oid {
if v < 0 {
return false
}
}
return true
}
func (b *Builder) AddASN1ObjectIdentifier(oid encoding_asn1.ObjectIdentifier) {
b.AddASN1(asn1.OBJECT_IDENTIFIER, func(b *Builder) {
if !isValidOID(oid) {
b.err = fmt.Errorf("cryptobyte: invalid OID: %v", oid)
return
}
b.addBase128Int(int64(oid[0])*40 + int64(oid[1]))
for _, v := range oid[2:] {
b.addBase128Int(int64(v))
}
})
}
func (b *Builder) AddASN1Boolean(v bool) {
b.AddASN1(asn1.BOOLEAN, func(b *Builder) {
if v {
b.AddUint8(0xff)
} else {
b.AddUint8(0)
}
})
}
func (b *Builder) AddASN1NULL() {
b.add(uint8(asn1.NULL), 0)
}
// MarshalASN1 calls encoding_asn1.Marshal on its input and appends the result if
// successful or records an error if one occurred.
func (b *Builder) MarshalASN1(v interface{}) {
// NOTE(martinkr): This is somewhat of a hack to allow propagation of
// asn1.Marshal errors into Builder.err. N.B. if you call MarshalASN1 with a
// encoding_asn1.Marshal errors into Builder.err. N.B. if you call MarshalASN1 with a
// value embedded into a struct, its tag information is lost.
if b.err != nil {
return
}
bytes, err := asn1.Marshal(v)
bytes, err := encoding_asn1.Marshal(v)
if err != nil {
b.err = err
return
@@ -148,7 +208,7 @@ func (b *Builder) MarshalASN1(v interface{}) {
// Tags greater than 30 are not supported and result in an error (i.e.
// low-tag-number form only). The child builder passed to the
// BuilderContinuation can be used to build the content of the ASN.1 object.
func (b *Builder) AddASN1(tag Tag, f BuilderContinuation) {
func (b *Builder) AddASN1(tag asn1.Tag, f BuilderContinuation) {
if b.err != nil {
return
}
@@ -164,6 +224,24 @@ func (b *Builder) AddASN1(tag Tag, f BuilderContinuation) {
// String
func (s *String) ReadASN1Boolean(out *bool) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.INTEGER) || len(bytes) != 1 {
return false
}
switch bytes[0] {
case 0:
*out = false
case 0xff:
*out = true
default:
return false
}
return true
}
var bigIntType = reflect.TypeOf((*big.Int)(nil)).Elem()
// ReadASN1Integer decodes an ASN.1 INTEGER into out and advances. If out does
@@ -215,7 +293,7 @@ var bigOne = big.NewInt(1)
func (s *String) readASN1BigInt(out *big.Int) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.TagInteger) || !checkASN1Integer(bytes) {
if !s.ReadASN1(&bytes, asn1.INTEGER) || !checkASN1Integer(bytes) {
return false
}
if bytes[0]&0x80 == 0x80 {
@@ -235,7 +313,7 @@ func (s *String) readASN1BigInt(out *big.Int) bool {
func (s *String) readASN1Int64(out *int64) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.TagInteger) || !checkASN1Integer(bytes) || !asn1Signed(out, bytes) {
if !s.ReadASN1(&bytes, asn1.INTEGER) || !checkASN1Integer(bytes) || !asn1Signed(out, bytes) {
return false
}
return true
@@ -258,7 +336,7 @@ func asn1Signed(out *int64, n []byte) bool {
func (s *String) readASN1Uint64(out *uint64) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.TagInteger) || !checkASN1Integer(bytes) || !asn1Unsigned(out, bytes) {
if !s.ReadASN1(&bytes, asn1.INTEGER) || !checkASN1Integer(bytes) || !asn1Unsigned(out, bytes) {
return false
}
return true
@@ -286,7 +364,7 @@ func asn1Unsigned(out *uint64, n []byte) bool {
func (s *String) ReadASN1Enum(out *int) bool {
var bytes String
var i int64
if !s.ReadASN1(&bytes, asn1.TagEnum) || !checkASN1Integer(bytes) || !asn1Signed(&i, bytes) {
if !s.ReadASN1(&bytes, asn1.ENUM) || !checkASN1Integer(bytes) || !asn1Signed(&i, bytes) {
return false
}
if int64(int(i)) != i {
@@ -315,9 +393,9 @@ func (s *String) readBase128Int(out *int) bool {
// ReadASN1ObjectIdentifier decodes an ASN.1 OBJECT IDENTIFIER into out and
// advances. It returns true on success and false on error.
func (s *String) ReadASN1ObjectIdentifier(out *asn1.ObjectIdentifier) bool {
func (s *String) ReadASN1ObjectIdentifier(out *encoding_asn1.ObjectIdentifier) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.TagOID) || len(bytes) == 0 {
if !s.ReadASN1(&bytes, asn1.OBJECT_IDENTIFIER) || len(bytes) == 0 {
return false
}
@@ -356,7 +434,7 @@ func (s *String) ReadASN1ObjectIdentifier(out *asn1.ObjectIdentifier) bool {
// advances. It returns true on success and false on error.
func (s *String) ReadASN1GeneralizedTime(out *time.Time) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.TagGeneralizedTime) {
if !s.ReadASN1(&bytes, asn1.GeneralizedTime) {
return false
}
t := string(bytes)
@@ -373,9 +451,9 @@ func (s *String) ReadASN1GeneralizedTime(out *time.Time) bool {
// ReadASN1BitString decodes an ASN.1 BIT STRING into out and advances. It
// returns true on success and false on error.
func (s *String) ReadASN1BitString(out *asn1.BitString) bool {
func (s *String) ReadASN1BitString(out *encoding_asn1.BitString) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.TagBitString) || len(bytes) == 0 {
if !s.ReadASN1(&bytes, asn1.BIT_STRING) || len(bytes) == 0 {
return false
}
@@ -392,10 +470,27 @@ func (s *String) ReadASN1BitString(out *asn1.BitString) bool {
return true
}
// ReadASN1BitString decodes an ASN.1 BIT STRING into out and advances. It is
// an error if the BIT STRING is not a whole number of bytes. This function
// returns true on success and false on error.
func (s *String) ReadASN1BitStringAsBytes(out *[]byte) bool {
var bytes String
if !s.ReadASN1(&bytes, asn1.BIT_STRING) || len(bytes) == 0 {
return false
}
paddingBits := uint8(bytes[0])
if paddingBits != 0 {
return false
}
*out = bytes[1:]
return true
}
// ReadASN1Bytes reads the contents of a DER-encoded ASN.1 element (not including
// tag and length bytes) into out, and advances. The element must match the
// given tag. It returns true on success and false on error.
func (s *String) ReadASN1Bytes(out *[]byte, tag Tag) bool {
func (s *String) ReadASN1Bytes(out *[]byte, tag asn1.Tag) bool {
return s.ReadASN1((*String)(out), tag)
}
@@ -404,8 +499,8 @@ func (s *String) ReadASN1Bytes(out *[]byte, tag Tag) bool {
// given tag. It returns true on success and false on error.
//
// Tags greater than 30 are not supported (i.e. low-tag-number format only).
func (s *String) ReadASN1(out *String, tag Tag) bool {
var t Tag
func (s *String) ReadASN1(out *String, tag asn1.Tag) bool {
var t asn1.Tag
if !s.ReadAnyASN1(out, &t) || t != tag {
return false
}
@@ -417,8 +512,8 @@ func (s *String) ReadASN1(out *String, tag Tag) bool {
// given tag. It returns true on success and false on error.
//
// Tags greater than 30 are not supported (i.e. low-tag-number format only).
func (s *String) ReadASN1Element(out *String, tag Tag) bool {
var t Tag
func (s *String) ReadASN1Element(out *String, tag asn1.Tag) bool {
var t asn1.Tag
if !s.ReadAnyASN1Element(out, &t) || t != tag {
return false
}
@@ -430,7 +525,7 @@ func (s *String) ReadASN1Element(out *String, tag Tag) bool {
// returns true on success and false on error.
//
// Tags greater than 30 are not supported (i.e. low-tag-number format only).
func (s *String) ReadAnyASN1(out *String, outTag *Tag) bool {
func (s *String) ReadAnyASN1(out *String, outTag *asn1.Tag) bool {
return s.readASN1(out, outTag, true /* skip header */)
}
@@ -439,24 +534,30 @@ func (s *String) ReadAnyASN1(out *String, outTag *Tag) bool {
// advances. It returns true on success and false on error.
//
// Tags greater than 30 are not supported (i.e. low-tag-number format only).
func (s *String) ReadAnyASN1Element(out *String, outTag *Tag) bool {
func (s *String) ReadAnyASN1Element(out *String, outTag *asn1.Tag) bool {
return s.readASN1(out, outTag, false /* include header */)
}
// PeekASN1Tag returns true if the next ASN.1 value on the string starts with
// the given tag.
func (s String) PeekASN1Tag(tag Tag) bool {
func (s String) PeekASN1Tag(tag asn1.Tag) bool {
if len(s) == 0 {
return false
}
return Tag(s[0]) == tag
return asn1.Tag(s[0]) == tag
}
// ReadOptionalASN1 attempts to read the contents of a DER-encoded ASN.Element
// (not including tag and length bytes) tagged with the given tag into out. It
// stores whether an element with the tag was found in outPresent, unless
// outPresent is nil. It returns true on success and false on error.
func (s *String) ReadOptionalASN1(out *String, outPresent *bool, tag Tag) bool {
// SkipASN1 reads and discards an ASN.1 element with the given tag.
func (s *String) SkipASN1(tag asn1.Tag) bool {
var unused String
return s.ReadASN1(&unused, tag)
}
// ReadOptionalASN1 attempts to read the contents of a DER-encoded ASN.1
// element (not including tag and length bytes) tagged with the given tag into
// out. It stores whether an element with the tag was found in outPresent,
// unless outPresent is nil. It returns true on success and false on error.
func (s *String) ReadOptionalASN1(out *String, outPresent *bool, tag asn1.Tag) bool {
present := s.PeekASN1Tag(tag)
if outPresent != nil {
*outPresent = present
@@ -467,12 +568,22 @@ func (s *String) ReadOptionalASN1(out *String, outPresent *bool, tag Tag) bool {
return true
}
// SkipOptionalASN1 advances s over an ASN.1 element with the given tag, or
// else leaves s unchanged.
func (s *String) SkipOptionalASN1(tag asn1.Tag) bool {
if !s.PeekASN1Tag(tag) {
return true
}
var unused String
return s.ReadASN1(&unused, tag)
}
// ReadOptionalASN1Integer attempts to read an optional ASN.1 INTEGER
// explicitly tagged with tag into out and advances. If no element with a
// matching tag is present, it writes defaultValue into out instead. If out
// does not point to an integer or to a big.Int, it panics. It returns true on
// success and false on error.
func (s *String) ReadOptionalASN1Integer(out interface{}, tag Tag, defaultValue interface{}) bool {
func (s *String) ReadOptionalASN1Integer(out interface{}, tag asn1.Tag, defaultValue interface{}) bool {
if reflect.TypeOf(out).Kind() != reflect.Ptr {
panic("out is not a pointer")
}
@@ -510,7 +621,7 @@ func (s *String) ReadOptionalASN1Integer(out interface{}, tag Tag, defaultValue
// explicitly tagged with tag into out and advances. If no element with a
// matching tag is present, it writes defaultValue into out instead. It returns
// true on success and false on error.
func (s *String) ReadOptionalASN1OctetString(out *[]byte, outPresent *bool, tag Tag) bool {
func (s *String) ReadOptionalASN1OctetString(out *[]byte, outPresent *bool, tag asn1.Tag) bool {
var present bool
var child String
if !s.ReadOptionalASN1(&child, &present, tag) {
@@ -521,7 +632,7 @@ func (s *String) ReadOptionalASN1OctetString(out *[]byte, outPresent *bool, tag
}
if present {
var oct String
if !child.ReadASN1(&oct, asn1.TagOctetString) || !child.Empty() {
if !child.ReadASN1(&oct, asn1.OCTET_STRING) || !child.Empty() {
return false
}
*out = oct
@@ -531,7 +642,24 @@ func (s *String) ReadOptionalASN1OctetString(out *[]byte, outPresent *bool, tag
return true
}
func (s *String) readASN1(out *String, outTag *Tag, skipHeader bool) bool {
// ReadOptionalASN1Boolean sets *out to the value of the next ASN.1 BOOLEAN or,
// if the next bytes are not an ASN.1 BOOLEAN, to the value of defaultValue.
func (s *String) ReadOptionalASN1Boolean(out *bool, defaultValue bool) bool {
var present bool
var child String
if !s.ReadOptionalASN1(&child, &present, asn1.BOOLEAN) {
return false
}
if !present {
*out = defaultValue
return true
}
return s.ReadASN1Boolean(out)
}
func (s *String) readASN1(out *String, outTag *asn1.Tag, skipHeader bool) bool {
if len(*s) < 2 {
return false
}
@@ -547,7 +675,7 @@ func (s *String) readASN1(out *String, outTag *Tag, skipHeader bool) bool {
}
if outTag != nil {
*outTag = Tag(tag)
*outTag = asn1.Tag(tag)
}
// ITU-T X.690 section 8.1.3

46
vendor/golang.org/x/crypto/cryptobyte/asn1/asn1.go generated vendored Normal file
View File

@@ -0,0 +1,46 @@
// 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 asn1 contains supporting types for parsing and building ASN.1
// messages with the cryptobyte package.
package asn1 // import "golang.org/x/crypto/cryptobyte/asn1"
// Tag represents an ASN.1 identifier octet, consisting of a tag number
// (indicating a type) and class (such as context-specific or constructed).
//
// Methods in the cryptobyte package only support the low-tag-number form, i.e.
// a single identifier octet with bits 7-8 encoding the class and bits 1-6
// encoding the tag number.
type Tag uint8
const (
classConstructed = 0x20
classContextSpecific = 0x80
)
// Constructed returns t with the constructed class bit set.
func (t Tag) Constructed() Tag { return t | classConstructed }
// ContextSpecific returns t with the context-specific class bit set.
func (t Tag) ContextSpecific() Tag { return t | classContextSpecific }
// The following is a list of standard tag and class combinations.
const (
BOOLEAN = Tag(1)
INTEGER = Tag(2)
BIT_STRING = Tag(3)
OCTET_STRING = Tag(4)
NULL = Tag(5)
OBJECT_IDENTIFIER = Tag(6)
ENUM = Tag(10)
UTF8String = Tag(12)
SEQUENCE = Tag(16 | classConstructed)
SET = Tag(17 | classConstructed)
PrintableString = Tag(19)
T61String = Tag(20)
IA5String = Tag(22)
UTCTime = Tag(23)
GeneralizedTime = Tag(24)
GeneralString = Tag(27)
)

View File

@@ -6,17 +6,19 @@ package cryptobyte
import (
"bytes"
"encoding/asn1"
encoding_asn1 "encoding/asn1"
"math/big"
"reflect"
"testing"
"time"
"golang.org/x/crypto/cryptobyte/asn1"
)
type readASN1Test struct {
name string
in []byte
tag Tag
tag asn1.Tag
ok bool
out interface{}
}
@@ -194,7 +196,7 @@ func TestReadASN1IntegerInvalid(t *testing.T) {
}
}
func TestReadASN1ObjectIdentifier(t *testing.T) {
func TestASN1ObjectIdentifier(t *testing.T) {
testData := []struct {
in []byte
ok bool
@@ -212,10 +214,23 @@ func TestReadASN1ObjectIdentifier(t *testing.T) {
for i, test := range testData {
in := String(test.in)
var out asn1.ObjectIdentifier
var out encoding_asn1.ObjectIdentifier
ok := in.ReadASN1ObjectIdentifier(&out)
if ok != test.ok || ok && !out.Equal(test.out) {
t.Errorf("#%d: in.ReadASN1ObjectIdentifier() = %v, want %v; out = %v, want %v", i, ok, test.ok, out, test.out)
continue
}
var b Builder
b.AddASN1ObjectIdentifier(out)
result, err := b.Bytes()
if builderOk := err == nil; test.ok != builderOk {
t.Errorf("#%d: error from Builder.Bytes: %s", i, err)
continue
}
if test.ok && !bytes.Equal(result, test.in) {
t.Errorf("#%d: reserialisation didn't match, got %x, want %x", i, result, test.in)
continue
}
}
}
@@ -250,7 +265,7 @@ func TestReadASN1GeneralizedTime(t *testing.T) {
{"201001020304-10Z", false, time.Time{}},
}
for i, test := range testData {
in := String(append([]byte{asn1.TagGeneralizedTime, byte(len(test.in))}, test.in...))
in := String(append([]byte{byte(asn1.GeneralizedTime), byte(len(test.in))}, test.in...))
var out time.Time
ok := in.ReadASN1GeneralizedTime(&out)
if ok != test.ok || ok && !reflect.DeepEqual(out, test.out) {
@@ -263,20 +278,20 @@ func TestReadASN1BitString(t *testing.T) {
testData := []struct {
in []byte
ok bool
out asn1.BitString
out encoding_asn1.BitString
}{
{[]byte{}, false, asn1.BitString{}},
{[]byte{0x00}, true, asn1.BitString{}},
{[]byte{0x07, 0x00}, true, asn1.BitString{Bytes: []byte{0}, BitLength: 1}},
{[]byte{0x07, 0x01}, false, asn1.BitString{}},
{[]byte{0x07, 0x40}, false, asn1.BitString{}},
{[]byte{0x08, 0x00}, false, asn1.BitString{}},
{[]byte{0xff}, false, asn1.BitString{}},
{[]byte{0xfe, 0x00}, false, asn1.BitString{}},
{[]byte{}, false, encoding_asn1.BitString{}},
{[]byte{0x00}, true, encoding_asn1.BitString{}},
{[]byte{0x07, 0x00}, true, encoding_asn1.BitString{Bytes: []byte{0}, BitLength: 1}},
{[]byte{0x07, 0x01}, false, encoding_asn1.BitString{}},
{[]byte{0x07, 0x40}, false, encoding_asn1.BitString{}},
{[]byte{0x08, 0x00}, false, encoding_asn1.BitString{}},
{[]byte{0xff}, false, encoding_asn1.BitString{}},
{[]byte{0xfe, 0x00}, false, encoding_asn1.BitString{}},
}
for i, test := range testData {
in := String(append([]byte{3, byte(len(test.in))}, test.in...))
var out asn1.BitString
var out encoding_asn1.BitString
ok := in.ReadASN1BitString(&out)
if ok != test.ok || ok && (!bytes.Equal(out.Bytes, test.out.Bytes) || out.BitLength != test.out.BitLength) {
t.Errorf("#%d: in.ReadASN1BitString() = %v, want %v; out = %v, want %v", i, ok, test.ok, out, test.out)

View File

@@ -10,15 +10,25 @@ import (
)
// A Builder builds byte strings from fixed-length and length-prefixed values.
// Builders either allocate space as needed, or are fixed, which means that
// they write into a given buffer and produce an error if it's exhausted.
//
// The zero value is a usable Builder that allocates space as needed.
//
// Simple values are marshaled and appended to a Builder using methods on the
// Builder. Length-prefixed values are marshaled by providing a
// BuilderContinuation, which is a function that writes the inner contents of
// the value to a given Builder. See the documentation for BuilderContinuation
// for details.
type Builder struct {
err error
result []byte
fixedSize bool
child *Builder
offset int
pendingLenLen int
pendingIsASN1 bool
err error
result []byte
fixedSize bool
child *Builder
offset int
pendingLenLen int
pendingIsASN1 bool
inContinuation *bool
}
// NewBuilder creates a Builder that appends its output to the given buffer.
@@ -86,9 +96,9 @@ func (b *Builder) AddBytes(v []byte) {
// BuilderContinuation is continuation-passing interface for building
// length-prefixed byte sequences. Builder methods for length-prefixed
// sequences (AddUint8LengthPrefixed etc.) will invoke the BuilderContinuation
// sequences (AddUint8LengthPrefixed etc) will invoke the BuilderContinuation
// supplied to them. The child builder passed to the continuation can be used
// to build the content of the length-prefixed sequence. Example:
// to build the content of the length-prefixed sequence. For example:
//
// parent := cryptobyte.NewBuilder()
// parent.AddUint8LengthPrefixed(func (child *Builder) {
@@ -102,8 +112,19 @@ func (b *Builder) AddBytes(v []byte) {
// length prefix. After the continuation returns, the child must be considered
// invalid, i.e. users must not store any copies or references of the child
// that outlive the continuation.
//
// If the continuation panics with a value of type BuildError then the inner
// error will be returned as the error from Bytes. If the child panics
// otherwise then Bytes will repanic with the same value.
type BuilderContinuation func(child *Builder)
// BuildError wraps an error. If a BuilderContinuation panics with this value,
// the panic will be recovered and the inner error will be returned from
// Builder.Bytes.
type BuildError struct {
Err error
}
// AddUint8LengthPrefixed adds a 8-bit length-prefixed byte sequence.
func (b *Builder) AddUint8LengthPrefixed(f BuilderContinuation) {
b.addLengthPrefixed(1, false, f)
@@ -119,6 +140,34 @@ func (b *Builder) AddUint24LengthPrefixed(f BuilderContinuation) {
b.addLengthPrefixed(3, false, f)
}
// AddUint32LengthPrefixed adds a big-endian, 32-bit length-prefixed byte sequence.
func (b *Builder) AddUint32LengthPrefixed(f BuilderContinuation) {
b.addLengthPrefixed(4, false, f)
}
func (b *Builder) callContinuation(f BuilderContinuation, arg *Builder) {
if !*b.inContinuation {
*b.inContinuation = true
defer func() {
*b.inContinuation = false
r := recover()
if r == nil {
return
}
if buildError, ok := r.(BuildError); ok {
b.err = buildError.Err
} else {
panic(r)
}
}()
}
f(arg)
}
func (b *Builder) addLengthPrefixed(lenLen int, isASN1 bool, f BuilderContinuation) {
// Subsequent writes can be ignored if the builder has encountered an error.
if b.err != nil {
@@ -128,15 +177,20 @@ func (b *Builder) addLengthPrefixed(lenLen int, isASN1 bool, f BuilderContinuati
offset := len(b.result)
b.add(make([]byte, lenLen)...)
b.child = &Builder{
result: b.result,
fixedSize: b.fixedSize,
offset: offset,
pendingLenLen: lenLen,
pendingIsASN1: isASN1,
if b.inContinuation == nil {
b.inContinuation = new(bool)
}
f(b.child)
b.child = &Builder{
result: b.result,
fixedSize: b.fixedSize,
offset: offset,
pendingLenLen: lenLen,
pendingIsASN1: isASN1,
inContinuation: b.inContinuation,
}
b.callContinuation(f, b.child)
b.flushChild()
if b.child != nil {
panic("cryptobyte: internal error")

View File

@@ -6,6 +6,7 @@ package cryptobyte
import (
"bytes"
"errors"
"fmt"
"testing"
)
@@ -18,6 +19,54 @@ func builderBytesEq(b *Builder, want ...byte) error {
return nil
}
func TestContinuationError(t *testing.T) {
const errorStr = "TestContinuationError"
var b Builder
b.AddUint8LengthPrefixed(func(b *Builder) {
b.AddUint8(1)
panic(BuildError{Err: errors.New(errorStr)})
})
ret, err := b.Bytes()
if ret != nil {
t.Error("expected nil result")
}
if err == nil {
t.Fatal("unexpected nil error")
}
if s := err.Error(); s != errorStr {
t.Errorf("expected error %q, got %v", errorStr, s)
}
}
func TestContinuationNonError(t *testing.T) {
defer func() {
recover()
}()
var b Builder
b.AddUint8LengthPrefixed(func(b *Builder) {
b.AddUint8(1)
panic(1)
})
t.Error("Builder did not panic")
}
func TestGeneratedPanic(t *testing.T) {
defer func() {
recover()
}()
var b Builder
b.AddUint8LengthPrefixed(func(b *Builder) {
var p *byte
*p = 0
})
t.Error("Builder did not panic")
}
func TestBytes(t *testing.T) {
var b Builder
v := []byte("foobarbaz")

View File

@@ -5,9 +5,11 @@
package cryptobyte_test
import (
"encoding/asn1"
"errors"
"fmt"
"golang.org/x/crypto/cryptobyte"
"golang.org/x/crypto/cryptobyte/asn1"
)
func ExampleString_lengthPrefixed() {
@@ -37,7 +39,7 @@ func ExampleString_lengthPrefixed() {
fmt.Printf("%#v\n", result)
}
func ExampleString_asn1() {
func ExampleString_aSN1() {
// This is an example of parsing ASN.1 data that looks like:
// Foo ::= SEQUENCE {
// version [6] INTEGER DEFAULT 0
@@ -51,12 +53,12 @@ func ExampleString_asn1() {
data, inner, versionBytes cryptobyte.String
haveVersion bool
)
if !input.ReadASN1(&inner, cryptobyte.Tag(asn1.TagSequence).Constructed()) ||
if !input.ReadASN1(&inner, asn1.SEQUENCE) ||
!input.Empty() ||
!inner.ReadOptionalASN1(&versionBytes, &haveVersion, cryptobyte.Tag(6).Constructed().ContextSpecific()) ||
!inner.ReadOptionalASN1(&versionBytes, &haveVersion, asn1.Tag(6).Constructed().ContextSpecific()) ||
(haveVersion && !versionBytes.ReadASN1Integer(&version)) ||
(haveVersion && !versionBytes.Empty()) ||
!inner.ReadASN1(&data, asn1.TagOctetString) ||
!inner.ReadASN1(&data, asn1.OCTET_STRING) ||
!inner.Empty() {
panic("bad format")
}
@@ -65,7 +67,7 @@ func ExampleString_asn1() {
fmt.Printf("haveVersion: %t, version: %d, data: %s\n", haveVersion, version, string(data))
}
func ExampleBuilder_asn1() {
func ExampleBuilder_aSN1() {
// This is an example of building ASN.1 data that looks like:
// Foo ::= SEQUENCE {
// version [6] INTEGER DEFAULT 0
@@ -77,9 +79,9 @@ func ExampleBuilder_asn1() {
const defaultVersion = 0
var b cryptobyte.Builder
b.AddASN1(cryptobyte.Tag(asn1.TagSequence).Constructed(), func(b *cryptobyte.Builder) {
b.AddASN1(asn1.SEQUENCE, func(b *cryptobyte.Builder) {
if version != defaultVersion {
b.AddASN1(cryptobyte.Tag(6).Constructed().ContextSpecific(), func(b *cryptobyte.Builder) {
b.AddASN1(asn1.Tag(6).Constructed().ContextSpecific(), func(b *cryptobyte.Builder) {
b.AddASN1Int64(version)
})
}
@@ -118,3 +120,35 @@ func ExampleBuilder_lengthPrefixed() {
// Output: 000c0568656c6c6f05776f726c64
fmt.Printf("%x\n", result)
}
func ExampleBuilder_lengthPrefixOverflow() {
// Writing more data that can be expressed by the length prefix results
// in an error from Bytes().
tooLarge := make([]byte, 256)
var b cryptobyte.Builder
b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) {
b.AddBytes(tooLarge)
})
result, err := b.Bytes()
fmt.Printf("len=%d err=%s\n", len(result), err)
// Output: len=0 err=cryptobyte: pending child length 256 exceeds 1-byte length prefix
}
func ExampleBuilderContinuation_errorHandling() {
var b cryptobyte.Builder
// Continuations that panic with a BuildError will cause Bytes to
// return the inner error.
b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) {
b.AddUint32(0)
panic(cryptobyte.BuildError{Err: errors.New("example error")})
})
result, err := b.Bytes()
fmt.Printf("len=%d err=%s\n", len(result), err)
// Output: len=0 err=example error
}

View File

@@ -2,9 +2,19 @@
// 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 contains types that help with parsing and constructing
// length-prefixed, binary messages, including ASN.1 DER. (The asn1 subpackage
// contains useful ASN.1 constants.)
//
// The String type is for parsing. It wraps a []byte slice and provides helper
// functions for consuming structures, value by value.
//
// The Builder type is for constructing messages. It providers helper functions
// for appending values and also for appending length-prefixed submessages
// without having to worry about calculating the length prefix ahead of time.
//
// See the documentation and 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