Ran gofmt on all files; forgot to do that after merging.

crypt.go

@@ -126,7 +126,6 @@ func encrypt(args []string) {
 		}
 	}
 
-
 	err = en.Encrypt(infd, outfd)
 	if err != nil {
 		die("%s", err)
@@ -220,7 +219,6 @@ func decrypt(args []string) {
 		outfd = outf
 	}
 
-
 	d, err := sign.NewDecryptor(infd)
 	if err != nil {
 		die("%s", err)
@@ -237,7 +235,6 @@ func decrypt(args []string) {
 	}
 }
 
-
 func encryptUsage(fs *flag.FlagSet) {
 	fmt.Printf(`%s encrypt: Encrypt a file to one or more recipients.
 

sign/encrypt.go

@@ -14,22 +14,21 @@
 package sign
 
 import (
+	"bytes"
 	"crypto/aes"
 	"crypto/cipher"
 	"crypto/ed25519"
 	"crypto/sha256"
 	"crypto/sha512"
 	"crypto/subtle"
+	"encoding/binary"
 	"fmt"
 	"golang.org/x/crypto/curve25519"
 	"golang.org/x/crypto/hkdf"
 	"io"
 	"math/big"
-	"bytes"
-	"encoding/binary"
 )
 
-
 // Encryption chunk size = 4MB
 const chunkSize int = 4 * 1048576
 
@@ -37,7 +36,6 @@ const _Magic = "SigTool"
 const _MagicLen = len(_Magic)
 const _AEADNonceLen = 32
 
-
 // Encryptor holds the encryption context
 type Encryptor struct {
 	Header
@@ -81,7 +79,6 @@ func NewEncryptor(sk *PrivateKey) (*Encryptor, error) {
 	return e, nil
 }
 
-
 // Add a new recipient to this encryption context.
 func (e *Encryptor) AddRecipient(pk *PublicKey) error {
 	if e.started {
@@ -104,7 +101,6 @@ func (e *Encryptor) AddRecipient(pk *PublicKey) error {
 	return nil
 }
 
-
 // Begin the encryption process by writing the header
 func (e *Encryptor) start(wr io.Writer) error {
 	msize := e.Size()
@@ -161,7 +157,6 @@ func fullwrite(buf []byte, wr io.Writer) error {
 	return nil
 }
 
-
 // Encrypt the input stream 'rd' and write encrypted stream to 'wr'
 func (e *Encryptor) Encrypt(rd io.Reader, wr io.Writer) error {
 	if !e.started {
@@ -225,7 +220,6 @@ func (e *Encryptor) encrypt(buf []byte, wr io.Writer, i int) error {
 	return nil
 }
 
-
 // Decryptor holds the decryption context
 type Decryptor struct {
 	Header
@@ -238,7 +232,6 @@ type Decryptor struct {
 	key []byte
 }
 
-
 // Create a new decryption context and if 'pk' is given, check that it matches
 // the sender
 func NewDecryptor(rd io.Reader) (*Decryptor, error) {
@@ -343,7 +336,6 @@ func (d *Decryptor) SetPrivateKey(sk *PrivateKey, senderPk *PublicKey) error {
 
 	return fmt.Errorf("decrypt: Can't find any public key to match the given private key")
 
-
 havekey:
 	aes, err := aes.NewCipher(d.key)
 	if err != nil {
@@ -363,7 +355,6 @@ func (d *Decryptor) WrappedKeys() []*WrappedKey {
 	return d.Keys
 }
 
-
 // Decrypt the file and write to 'wr'
 func (d *Decryptor) Decrypt(wr io.Writer) error {
 	if d.key == nil {
@@ -403,8 +394,13 @@ func (d *Decryptor) decrypt(i int) ([]byte, error) {
 		return nil, fmt.Errorf("decrypt: can't read chunk %d length: %s", i, err)
 	}
 
-
 	chunklen := int(binary.BigEndian.Uint32(b[:4]))
+
+	// Sanity check - in case of corrupt header
+	if chunklen > (d.ae.Overhead()+chunkSize) {
+		return nil, fmt.Errorf("decrypt: chunksize is too large (%d)", chunklen)
+	}
+
 	binary.BigEndian.PutUint32(b[4:], uint32(i))
 	h := sha256.New()
 	h.Write(d.Salt)
@@ -448,7 +444,6 @@ func (sk *PrivateKey) WrapKey(pk *PublicKey, key []byte) (*WrappedKey, error) {
 	return wrapKey(pk, key, &ourSK)
 }
 
-
 func wrapKey(pk *PublicKey, k []byte, ourSK *[32]byte) (*WrappedKey, error) {
 	var curvePK, theirPK, shared [32]byte
 
@@ -469,8 +464,6 @@ func wrapKey(pk *PublicKey, k []byte, ourSK *[32]byte) (*WrappedKey, error) {
 	}, nil
 }
 
-
-
 // Unwrap a wrapped key using the private key 'sk'
 func (w *WrappedKey) UnwrapKey(sk *PrivateKey, senderPk *PublicKey) ([]byte, error) {
 	var shared, theirPK, ourSK [32]byte
@@ -501,7 +494,6 @@ func (w *WrappedKey) UnwrapKey(sk *PrivateKey, senderPk *PublicKey) ([]byte, err
 	return key, nil
 }
 
-
 // Convert an Ed25519 Private Key to Curve25519 Private key
 func (sk *PrivateKey) toCurve25519SK() []byte {
 	if sk.ck == nil {
@@ -565,7 +557,6 @@ func expand(shared, pk []byte) ([]byte, error) {
 	return kek, err
 }
 
-
 // seal the data via AEAD after suitably expanding 'shared'
 func aeadSeal(data, shared, pk []byte) ([]byte, []byte, error) {
 	kek, err := expand(shared[:], pk)
@@ -624,7 +615,6 @@ func aeadOpen(data, nonce, shared, pk []byte) ([]byte, error) {
 	return c, nil
 }
 
-
 func clamp(k []byte) []byte {
 	k[0] &= 248
 	k[31] &= 127

sign/sign.go

@@ -223,7 +223,6 @@ func MakePrivateKey(yml []byte, pw string) (*PrivateKey, error) {
 		return nil, fmt.Errorf("can't decode YAML:Verify: %s", err)
 	}
 
-
 	// We take short passwords and extend them
 	pwb := sha512.Sum512([]byte(pw))
 
@@ -250,7 +249,6 @@ func MakePrivateKey(yml []byte, pw string) (*PrivateKey, error) {
 	return PrivateKeyFromBytes(skb)
 }
 
-
 // Make a private key from 64-bytes of extended Ed25519 key
 func PrivateKeyFromBytes(skb []byte) (*PrivateKey, error) {
 	if len(skb) != 64 {
@@ -272,7 +270,6 @@ func PrivateKeyFromBytes(skb []byte) (*PrivateKey, error) {
 	return sk, nil
 }
 
-
 // Given a secret key, return the corresponding Public Key
 func (sk *PrivateKey) PublicKey() *PublicKey {
 	return sk.pk
@@ -481,7 +478,6 @@ func MakePublicKey(yml []byte) (*PublicKey, error) {
 	return PublicKeyFromBytes(pk)
 }
 
-
 // Make a public key from a byte string
 func PublicKeyFromBytes(b []byte) (*PublicKey, error) {
 	if len(b) != 32 {

sign/sign_test.go

@@ -90,7 +90,6 @@ r: 8
 p: 1
 `
 
-
 // #1. Create new key pair, and read them back.
 func Test0(t *testing.T) {
 	assert := newAsserter(t)

version

@@ -1 +1 @@
-0.2.0
+0.2.1