cmd/age: add a prototype of the command line tool

internal/age/age.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age
 
 import (

internal/age/age_test.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age_test
 
 import (

internal/age/primitives.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age
 
 import (

internal/age/recipients_test.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age_test
 
 import (

internal/age/scrypt.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age
 
 import (

internal/age/ssh.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age
 
 import (

internal/age/x25519.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package age
 
 import (
@@ -6,6 +12,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 
 	"github.com/FiloSottile/age/internal/format"
 	"golang.org/x/crypto/chacha20poly1305"
@@ -32,6 +39,22 @@ func NewX25519Recipient(publicKey []byte) (*X25519Recipient, error) {
 	return r, nil
 }
 
+func ParseX25519Recipient(s string) (*X25519Recipient, error) {
+	if !strings.HasPrefix(s, "pubkey:") {
+		return nil, fmt.Errorf("malformed recipient: %s", s)
+	}
+	pubKey := strings.TrimPrefix(s, "pubkey:")
+	k, err := format.DecodeString(pubKey)
+	if err != nil {
+		return nil, fmt.Errorf("malformed recipient: %s", s)
+	}
+	r, err := NewX25519Recipient(k)
+	if err != nil {
+		return nil, fmt.Errorf("malformed recipient: %s", s)
+	}
+	return r, nil
+}
+
 func (r *X25519Recipient) Wrap(fileKey []byte) (*format.Recipient, error) {
 	var ephemeral, ourPublicKey [32]byte
 	if _, err := rand.Read(ephemeral[:]); err != nil {
@@ -65,6 +88,10 @@ func (r *X25519Recipient) Wrap(fileKey []byte) (*format.Recipient, error) {
 	return l, nil
 }
 
+func (r *X25519Recipient) String() string {
+	return "pubkey:" + format.EncodeToString(r.theirPublicKey[:])
+}
+
 type X25519Identity struct {
 	secretKey, ourPublicKey [32]byte
 }
@@ -83,6 +110,22 @@ func NewX25519Identity(secretKey []byte) (*X25519Identity, error) {
 	return i, nil
 }
 
+func ParseX25519Identity(s string) (*X25519Identity, error) {
+	if !strings.HasPrefix(s, "AGE_SECRET_KEY_") {
+		return nil, fmt.Errorf("malformed secret key: %s", s)
+	}
+	privKey := strings.TrimPrefix(s, "AGE_SECRET_KEY_")
+	k, err := format.DecodeString(privKey)
+	if err != nil {
+		return nil, fmt.Errorf("malformed secret key: %s", s)
+	}
+	r, err := NewX25519Identity(k)
+	if err != nil {
+		return nil, fmt.Errorf("malformed secret key: %s", s)
+	}
+	return r, nil
+}
+
 func (i *X25519Identity) Unwrap(block *format.Recipient) ([]byte, error) {
 	if block.Type != "X25519" {
 		return nil, errors.New("wrong recipient block type")
@@ -121,3 +164,13 @@ func (i *X25519Identity) Unwrap(block *format.Recipient) ([]byte, error) {
 	}
 	return fileKey, nil
 }
+
+func (i *X25519Identity) Recipient() *X25519Recipient {
+	r := &X25519Recipient{}
+	r.theirPublicKey = i.ourPublicKey
+	return r
+}
+
+func (i *X25519Identity) String() string {
+	return "AGE_SECRET_KEY_" + format.EncodeToString(i.secretKey[:])
+}

internal/format/format.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package format
 
 import (

internal/stream/stream.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package stream
 
 import (
@@ -156,8 +162,7 @@ func (w *Writer) Write(p []byte) (n int, err error) {
 
 	total := len(p)
 	for len(p) > 0 {
-		free := ChunkSize - len(w.unwritten)
-		freeBuf := w.buf[len(w.unwritten) : len(w.unwritten)+free]
+		freeBuf := w.buf[len(w.unwritten):ChunkSize]
 		n := copy(freeBuf, p)
 		p = p[n:]
 		w.unwritten = w.unwritten[:len(w.unwritten)+n]

internal/stream/stream_test.go

@@ -1,3 +1,9 @@
+// Copyright 2019 Google LLC
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
 package stream_test
 
 import (