1 files changed, 67 insertions, 40 deletions

diff --git a/vendor/github.com/rs/xid/id.go b/vendor/github.com/rs/xid/id.go
index 466faf262..1f536b415 100644
--- a/vendor/github.com/rs/xid/id.go
+++ b/vendor/github.com/rs/xid/id.go
@@ -47,7 +47,6 @@ import (
 	"crypto/rand"
 	"database/sql/driver"
 	"encoding/binary"
-	"errors"
 	"fmt"
 	"hash/crc32"
 	"io/ioutil"
@@ -55,6 +54,7 @@ import (
 	"sort"
 	"sync/atomic"
 	"time"
+	"unsafe"
 )
 
 // Code inspired from mgo/bson ObjectId
@@ -72,9 +72,6 @@ const (
 )
 
 var (
-	// ErrInvalidID is returned when trying to unmarshal an invalid ID
-	ErrInvalidID = errors.New("xid: invalid ID")
-
 	// objectIDCounter is atomically incremented when generating a new ObjectId
 	// using NewObjectId() function. It's used as a counter part of an id.
 	// This id is initialized with a random value.
@@ -177,7 +174,13 @@ func FromString(id string) (ID, error) {
 func (id ID) String() string {
 	text := make([]byte, encodedLen)
 	encode(text, id[:])
-	return string(text)
+	return *(*string)(unsafe.Pointer(&text))
+}
+
+// Encode encodes the id using base32 encoding, writing 20 bytes to dst and return it.
+func (id ID) Encode(dst []byte) []byte {
+	encode(dst, id[:])
+	return dst
 }
 
 // MarshalText implements encoding/text TextMarshaler interface
@@ -192,32 +195,37 @@ func (id ID) MarshalJSON() ([]byte, error) {
 	if id.IsNil() {
 		return []byte("null"), nil
 	}
-	text, err := id.MarshalText()
-	return []byte(`"` + string(text) + `"`), err
+	text := make([]byte, encodedLen+2)
+	encode(text[1:encodedLen+1], id[:])
+	text[0], text[encodedLen+1] = '"', '"'
+	return text, nil
 }
 
 // encode by unrolling the stdlib base32 algorithm + removing all safe checks
 func encode(dst, id []byte) {
-	dst[0] = encoding[id[0]>>3]
-	dst[1] = encoding[(id[1]>>6)&0x1F|(id[0]<<2)&0x1F]
-	dst[2] = encoding[(id[1]>>1)&0x1F]
-	dst[3] = encoding[(id[2]>>4)&0x1F|(id[1]<<4)&0x1F]
-	dst[4] = encoding[id[3]>>7|(id[2]<<1)&0x1F]
-	dst[5] = encoding[(id[3]>>2)&0x1F]
-	dst[6] = encoding[id[4]>>5|(id[3]<<3)&0x1F]
-	dst[7] = encoding[id[4]&0x1F]
-	dst[8] = encoding[id[5]>>3]
-	dst[9] = encoding[(id[6]>>6)&0x1F|(id[5]<<2)&0x1F]
-	dst[10] = encoding[(id[6]>>1)&0x1F]
-	dst[11] = encoding[(id[7]>>4)&0x1F|(id[6]<<4)&0x1F]
-	dst[12] = encoding[id[8]>>7|(id[7]<<1)&0x1F]
-	dst[13] = encoding[(id[8]>>2)&0x1F]
-	dst[14] = encoding[(id[9]>>5)|(id[8]<<3)&0x1F]
-	dst[15] = encoding[id[9]&0x1F]
-	dst[16] = encoding[id[10]>>3]
-	dst[17] = encoding[(id[11]>>6)&0x1F|(id[10]<<2)&0x1F]
-	dst[18] = encoding[(id[11]>>1)&0x1F]
+	_ = dst[19]
+	_ = id[11]
+
 	dst[19] = encoding[(id[11]<<4)&0x1F]
+	dst[18] = encoding[(id[11]>>1)&0x1F]
+	dst[17] = encoding[(id[11]>>6)&0x1F|(id[10]<<2)&0x1F]
+	dst[16] = encoding[id[10]>>3]
+	dst[15] = encoding[id[9]&0x1F]
+	dst[14] = encoding[(id[9]>>5)|(id[8]<<3)&0x1F]
+	dst[13] = encoding[(id[8]>>2)&0x1F]
+	dst[12] = encoding[id[8]>>7|(id[7]<<1)&0x1F]
+	dst[11] = encoding[(id[7]>>4)&0x1F|(id[6]<<4)&0x1F]
+	dst[10] = encoding[(id[6]>>1)&0x1F]
+	dst[9] = encoding[(id[6]>>6)&0x1F|(id[5]<<2)&0x1F]
+	dst[8] = encoding[id[5]>>3]
+	dst[7] = encoding[id[4]&0x1F]
+	dst[6] = encoding[id[4]>>5|(id[3]<<3)&0x1F]
+	dst[5] = encoding[(id[3]>>2)&0x1F]
+	dst[4] = encoding[id[3]>>7|(id[2]<<1)&0x1F]
+	dst[3] = encoding[(id[2]>>4)&0x1F|(id[1]<<4)&0x1F]
+	dst[2] = encoding[(id[1]>>1)&0x1F]
+	dst[1] = encoding[(id[1]>>6)&0x1F|(id[0]<<2)&0x1F]
+	dst[0] = encoding[id[0]>>3]
 }
 
 // UnmarshalText implements encoding/text TextUnmarshaler interface
@@ -230,7 +238,9 @@ func (id *ID) UnmarshalText(text []byte) error {
 			return ErrInvalidID
 		}
 	}
-	decode(id, text)
+	if !decode(id, text) {
+		return ErrInvalidID
+	}
 	return nil
 }
 
@@ -241,23 +251,40 @@ func (id *ID) UnmarshalJSON(b []byte) error {
 		*id = nilID
 		return nil
 	}
+	// Check the slice length to prevent panic on passing it to UnmarshalText()
+	if len(b) < 2 {
+		return ErrInvalidID
+	}
 	return id.UnmarshalText(b[1 : len(b)-1])
 }
 
-// decode by unrolling the stdlib base32 algorithm + removing all safe checks
-func decode(id *ID, src []byte) {
-	id[0] = dec[src[0]]<<3 | dec[src[1]]>>2
-	id[1] = dec[src[1]]<<6 | dec[src[2]]<<1 | dec[src[3]]>>4
-	id[2] = dec[src[3]]<<4 | dec[src[4]]>>1
-	id[3] = dec[src[4]]<<7 | dec[src[5]]<<2 | dec[src[6]]>>3
-	id[4] = dec[src[6]]<<5 | dec[src[7]]
-	id[5] = dec[src[8]]<<3 | dec[src[9]]>>2
-	id[6] = dec[src[9]]<<6 | dec[src[10]]<<1 | dec[src[11]]>>4
-	id[7] = dec[src[11]]<<4 | dec[src[12]]>>1
-	id[8] = dec[src[12]]<<7 | dec[src[13]]<<2 | dec[src[14]]>>3
-	id[9] = dec[src[14]]<<5 | dec[src[15]]
-	id[10] = dec[src[16]]<<3 | dec[src[17]]>>2
+// decode by unrolling the stdlib base32 algorithm + customized safe check.
+func decode(id *ID, src []byte) bool {
+	_ = src[19]
+	_ = id[11]
+
 	id[11] = dec[src[17]]<<6 | dec[src[18]]<<1 | dec[src[19]]>>4
+	id[10] = dec[src[16]]<<3 | dec[src[17]]>>2
+	id[9] = dec[src[14]]<<5 | dec[src[15]]
+	id[8] = dec[src[12]]<<7 | dec[src[13]]<<2 | dec[src[14]]>>3
+	id[7] = dec[src[11]]<<4 | dec[src[12]]>>1
+	id[6] = dec[src[9]]<<6 | dec[src[10]]<<1 | dec[src[11]]>>4
+	id[5] = dec[src[8]]<<3 | dec[src[9]]>>2
+	id[4] = dec[src[6]]<<5 | dec[src[7]]
+	id[3] = dec[src[4]]<<7 | dec[src[5]]<<2 | dec[src[6]]>>3
+	id[2] = dec[src[3]]<<4 | dec[src[4]]>>1
+	id[1] = dec[src[1]]<<6 | dec[src[2]]<<1 | dec[src[3]]>>4
+	id[0] = dec[src[0]]<<3 | dec[src[1]]>>2
+
+	// Validate that there are no discarer bits (padding) in src that would
+	// cause the string-encoded id not to equal src.
+	var check [4]byte
+
+	check[3] = encoding[(id[11]<<4)&0x1F]
+	check[2] = encoding[(id[11]>>1)&0x1F]
+	check[1] = encoding[(id[11]>>6)&0x1F|(id[10]<<2)&0x1F]
+	check[0] = encoding[id[10]>>3]
+	return bytes.Equal([]byte(src[16:20]), check[:])
 }
 
 // Time returns the timestamp part of the id.