3 files changed, 0 insertions, 595 deletions
diff --git a/internal/cryptoutil/cryptoutil.go b/internal/cryptoutil/cryptoutil.go
deleted file mode 100644
index 0429b02..0000000
--- a/internal/cryptoutil/cryptoutil.go
+++ /dev/null
@@ -1,139 +0,0 @@
-// Package cryptoutil contains friendly wrappers around the algorithms from the
-// standard library's crypto package.
-package cryptoutil
-
-import (
-	"crypto/hkdf"
-	"crypto/hmac"
-	"crypto/pbkdf2"
-	"crypto/rand"
-	"crypto/sha512"
-	"crypto/subtle"
-	"encoding/binary"
-	"encoding/hex"
-	"errors"
-	"io"
-)
-
-const (
-	defaultIterations = 4718580 // from cmd/finditers
-
-	oneSaltSize = 64
-	hashSize    = 64
-	certSize    = sha512.Size
-)
-
-// SaltSize is the expected salt length for HashIter.
-const SaltSize = 2 * oneSaltSize
-
-// A PasswordHash must be PasswordHashSize bytes.
-const PasswordHashSize = SaltSize + hashSize
-
-// A PasswordHash is derived from the user's password and can be passed to
-// CheckPassword to verify if two passwords match. A PasswordHash must be
-// PasswordHashSize bytes.
-type PasswordHash []byte
-
-func (h PasswordHash) String() string { return hex.EncodeToString(h) }
-
-// A RawKey is generated from a password hash and can be used to derive further
-// key material.
-type RawKey struct {
-	key []byte
-}
-
-// An HMACKey must be HMACKeySize bytes.
-const HMACKeySize = sha512.BlockSize
-
-// An HMAC key can be used to symmetrically sign and verify messages
-// using HMAC-SHA512. An HMACKey must be HMACKeyLen bytes.
-type HMACKey []byte
-
-// A SignedMessage is a message that has been cryptographically signed
-// with HMAC-SHA512.
-type SignedMessage []byte
-
-// An EncryptedMessage is encrypted with AES-256-CTR-HMAC-SHA512.
-type EncryptedMessage []byte
-
-// HashIter runs PBKDF2-SHA512 for iter iterations. Useful for benchmarking. The
-// salt must be SaltSize bytes.
-func HashIter(password string, salt []byte, iter int) ([]byte, error) {
-	return pbkdf2.Key(sha512.New, password, salt, iter, sha512.Size)
-}
-
-func hashWithSalt(password string, salt []byte) (RawKey, []byte, error) {
-	hash, err := HashIter(password, salt[:oneSaltSize], defaultIterations)
-	if err != nil {
-		return RawKey{}, nil, err
-	}
-	key, err := hkdf.Extract(sha512.New, hash, salt[oneSaltSize:])
-	if err != nil {
-		return RawKey{}, nil, err
-	}
-	pwHash, err := hkdf.Expand(sha512.New, key, "pwhash", hashSize)
-	if err != nil {
-		return RawKey{}, nil, err
-	}
-	return RawKey{key}, pwHash, nil
-}
-
-// Hash hashes a user password using PBKDF2-SHA512.
-func Hash(password string) (PasswordHash, error) {
-	salt := make([]byte, SaltSize, SaltSize+hashSize)
-	rand.Read(salt)
-	_, pwHash, err := hashWithSalt(password, salt)
-	if err != nil {
-		return nil, err
-	}
-	return append(salt, pwHash...), nil
-}
-
-// CheckPassword verifies password against a PasswordHash and returns an
-// EncryptionKey derived from the password if successful.
-func (h PasswordHash) CheckPassword(password string) (RawKey, error) {
-	salt, expectedHash := h[:SaltSize], h[SaltSize:]
-	key, pwHash, err := hashWithSalt(password, salt)
-	if err != nil {
-		return RawKey{}, err
-	}
-	if subtle.ConstantTimeCompare(pwHash, expectedHash) == 0 {
-		return RawKey{}, errors.New("incorrect password")
-	}
-	return key, nil
-}
-
-func (k HMACKey) mac(out, msg []byte, info string) []byte {
-	mac := hmac.New(sha512.New, k)
-	buf := make([]byte, 0, binary.MaxVarintLen64)
-	mac.Write(binary.AppendUvarint(buf, uint64(len(info))))
-	io.WriteString(mac, info)
-	mac.Write(msg)
-	return mac.Sum(out)
-}
-
-// Sign generates an HMAC-SHA512 signature and appends it to msg. The info and
-// additionalData are also authenticated, but are not included in the returned
-// signed message.
-func (k HMACKey) Sign(msg []byte, info string) SignedMessage {
-	return k.mac(msg, msg, info)
-}
-
-// Verify checks whether the given message has a valid signature, and returns
-// the raw message if it does. The additionalData must match the data passed
-// to Sign.
-func (k HMACKey) Verify(msg SignedMessage, info string) ([]byte, bool) {
-	if len(msg) < certSize {
-		return nil, false
-	}
-	msg, sig := msg[:len(msg)-certSize], msg[len(msg)-certSize:]
-	if !hmac.Equal(sig, k.mac(nil, msg, info)) {
-		return nil, false
-	}
-	return msg, true
-}
-
-// EncryptionKey derives an EncryptionKey.
-func (k RawKey) EncryptionKey() (EncryptionKey, error) {
-	return hkdf.Expand(sha512.New, k.key, "encrypt", sha512.Size)
-}
diff --git a/internal/cryptoutil/cryptoutil_test.go b/internal/cryptoutil/cryptoutil_test.go
deleted file mode 100644
index 059a9e1..0000000
--- a/internal/cryptoutil/cryptoutil_test.go
+++ /dev/null
@@ -1,159 +0,0 @@
-package cryptoutil
-
-import (
-	"bytes"
-	"encoding/hex"
-	"io"
-	"testing"
-)
-
-func mustHex(t testing.TB, s string) []byte {
-	t.Helper()
-	bytes, err := hex.DecodeString(s)
-	if err != nil {
-		t.Fatalf("Bad hex %q: %s", s, err)
-	}
-	return bytes
-}
-
-func TestPassword(t *testing.T) {
-	const password = "eclair scroll gliding sled shining removed ascend android cheer confetti"
-	hash, err := Hash(password)
-	if err != nil {
-		t.Fatalf("Hash(%q) failed: %s", password, err)
-	}
-	_, err = hash.CheckPassword(password)
-	if err != nil {
-		t.Errorf("%x.CheckPassword(%q) failed: %s", hash, password, err)
-	}
-}
-
-func TestSignature(t *testing.T) {
-	key := HMACKey(mustHex(t, "669e06ec457778b9a8133edb0a87ea82c6b141ffbbc63c038da96258175eb35c"))
-	msg := []byte("test message")
-	signedMsg := key.Sign(msg, "info")
-	got, ok := key.Verify(signedMsg, "info")
-	if !ok {
-		t.Fatalf("Verify(%x) rejected the message", signedMsg)
-	}
-	if !bytes.Equal(got, msg) {
-		t.Errorf("Verify(%x) = %x, want %x", signedMsg, got, msg)
-	}
-}
-
-func TestEncrypt(t *testing.T) {
-	key := EncryptionKey(mustHex(t, "b6de26860e0a39aa134732e58055c06ba028675453f73a6912bc932e58d5743d0e423217f06487d3e96a59980301fcc97dfcc4c6b19765f2947de3c33ab7ef9e"))
-	for _, tc := range []struct {
-		desc string
-		msg  []byte
-	}{{
-		desc: "empty",
-		msg:  nil,
-	}, {
-		desc: "short",
-		msg:  []byte("test message"),
-	}, {
-		desc: "long",
-		msg: func() []byte {
-			msg := make([]byte, 1024*1024)
-			for i := range msg {
-				msg[i] = byte(i)
-			}
-			return msg
-		}(),
-	}} {
-		t.Run(tc.desc, func(t *testing.T) {
-			encryptedMsg := new(bytes.Buffer)
-			w := key.NewWriter(encryptedMsg, WithAdditionalData([]byte("additional data")))
-			if _, err := w.Write(tc.msg); err != nil {
-				t.Fatalf("EncryptingWriter.Write(%q) failed: %s", tc.msg, err)
-			}
-			if err := w.Close(); err != nil {
-				t.Fatalf("EncryptingWriter.Close() failed: %s", err)
-			}
-			got, err := io.ReadAll(key.NewReader(bytes.NewReader(encryptedMsg.Bytes()), WithAdditionalData([]byte("additional data"))))
-			if err != nil {
-				t.Fatalf("DecryptingReader.Read(%x) failed: %s", encryptedMsg, err)
-			}
-			if !bytes.Equal(got, tc.msg) {
-				t.Errorf("DecryptingReader.Read(%x) = %x, want %x", encryptedMsg, got, tc.msg)
-			}
-		})
-	}
-}
-
-func TestDeriveKey(t *testing.T) {
-	const password = "automaker moisture botch tubular kelp rinse rule giggly donated stock"
-	hash, err := Hash(password)
-	if err != nil {
-		t.Fatalf("Hash(%q) failed: %s", password, err)
-	}
-	rawKey, err := hash.CheckPassword(password)
-	if err != nil {
-		t.Fatalf("%x.CheckPassword(%q) failed: %s", hash, password, err)
-	}
-	key, err := rawKey.EncryptionKey()
-	if err != nil {
-		t.Fatalf("EncryptionKey() failed: %s", err)
-	}
-	msg := []byte("test message")
-	encryptedMsg := new(bytes.Buffer)
-	w := key.NewWriter(encryptedMsg, WithAdditionalData([]byte("additional data")))
-	if _, err := w.Write(msg); err != nil {
-		t.Fatalf("EncryptingWriter.Write(%q) failed: %s", msg, err)
-	}
-	if err := w.Close(); err != nil {
-		t.Fatalf("EncryptingWriter.Close() failed: %s", err)
-	}
-	got, err := io.ReadAll(key.NewReader(encryptedMsg, WithAdditionalData([]byte("additional data"))))
-	if err != nil {
-		t.Fatalf("DecryptingReader.Read(%x) failed: %s", encryptedMsg, err)
-	}
-	if !bytes.Equal(got, msg) {
-		t.Errorf("DecryptingReader.Read(%x) = %x, want %x", encryptedMsg, got, msg)
-	}
-}
-
-func BenchmarkEncrypt(b *testing.B) {
-	key := EncryptionKey(mustHex(b, "b6de26860e0a39aa134732e58055c06ba028675453f73a6912bc932e58d5743d0e423217f06487d3e96a59980301fcc97dfcc4c6b19765f2947de3c33ab7ef9e"))
-	msg := make([]byte, 1024*1024)
-	for i := range msg {
-		msg[i] = byte(i)
-	}
-	encryptedMsg := bytes.NewBuffer(make([]byte, 0, 35+len(msg)+16*(len(msg)+defaultOpts.segmentSize-1)/defaultOpts.segmentSize /* ?? */))
-	additionalData := []byte("additional data")
-	for b.Loop() {
-		w := key.NewWriter(encryptedMsg, WithAdditionalData(additionalData))
-		if _, err := w.Write(msg); err != nil {
-			b.Fatal(err)
-		}
-		if err := w.Close(); err != nil {
-			b.Fatal(err)
-		}
-		encryptedMsg.Reset()
-	}
-}
-
-func BenchmarkDecrypt(b *testing.B) {
-	key := EncryptionKey(mustHex(b, "b6de26860e0a39aa134732e58055c06ba028675453f73a6912bc932e58d5743d0e423217f06487d3e96a59980301fcc97dfcc4c6b19765f2947de3c33ab7ef9e"))
-	msg := make([]byte, 1024*1024)
-	for i := range msg {
-		msg[i] = byte(i)
-	}
-	encryptedMsg := new(bytes.Buffer)
-	additionalData := []byte("additional data")
-	w := key.NewWriter(encryptedMsg, WithAdditionalData(additionalData))
-	if _, err := w.Write(msg); err != nil {
-		b.Fatal(err)
-	}
-	if err := w.Close(); err != nil {
-		b.Fatal(err)
-	}
-	decryptedMsg := make([]byte, len(msg))
-	for b.Loop() {
-		r := key.NewReader(bytes.NewReader(encryptedMsg.Bytes()), WithAdditionalData(additionalData))
-		if _, err := io.ReadFull(r, decryptedMsg); err != nil {
-			b.Fatal(err)
-		}
-	}
-}
diff --git a/internal/cryptoutil/oae2.go b/internal/cryptoutil/oae2.go
deleted file mode 100644
index bc8f53e..0000000
--- a/internal/cryptoutil/oae2.go
+++ /dev/null
@@ -1,297 +0,0 @@
-package cryptoutil
-
-import (
-	"bufio"
-	"bytes"
-	"crypto/aes"
-	"crypto/cipher"
-	"crypto/hkdf"
-	"crypto/rand"
-	"crypto/sha512"
-	"encoding/binary"
-	"errors"
-	"io"
-)
-
-// Online Authenticated Encryption from https://eprint.iacr.org/2015/189.pdf
-
-const (
-	aeadOverhead    = 16
-	aesKeySize      = 32
-	noncePrefixSize = 3
-	gcmNonceSize    = 12
-	headerSize      = aesKeySize + noncePrefixSize
-)
-
-// An EncryptionKey is used for encrypting and decrypting data. A key can be any
-// length, but at least 64 bytes would be recommended.
-type EncryptionKey []byte
-
-type oae2 struct {
-	key            EncryptionKey
-	additionalData []byte
-
-	aead        cipher.AEAD
-	i           int64
-	noncePrefix [noncePrefixSize]byte
-}
-
-func (o *oae2) initialize(header []byte) error {
-	o.i = 1
-	copy(o.noncePrefix[:], header[aesKeySize:])
-	derivedKey, err := hkdf.Key(sha512.New, o.key, header[:aesKeySize], "", aesKeySize)
-	if err != nil {
-		return err
-	}
-	block, err := aes.NewCipher(derivedKey)
-	if err != nil {
-		return err
-	}
-	o.aead, err = cipher.NewGCM(block)
-	return err
-}
-
-func (o *oae2) nonce(nonce []byte, lastBlock bool) error {
-	copy(nonce, o.noncePrefix[:])
-	if o.i < 0 {
-		return errors.New("counter overflowed (64 bits??)")
-	}
-	binary.BigEndian.PutUint64(nonce[noncePrefixSize:], uint64(o.i))
-	if lastBlock {
-		nonce[gcmNonceSize-1] = 1
-	}
-	return nil
-}
-
-func (o *oae2) encryptBlock(out, block []byte, lastBlock bool) ([]byte, error) {
-	nonce := make([]byte, gcmNonceSize)
-	if err := o.nonce(nonce, lastBlock); err != nil {
-		return nil, err
-	}
-	encrypted := o.aead.Seal(out, nonce, block, o.additionalData)
-	o.i++
-	o.additionalData = nil
-	return encrypted, nil
-}
-
-func (o *oae2) decryptBlock(out, block []byte, lastBlock bool) ([]byte, error) {
-	nonce := make([]byte, gcmNonceSize)
-	if err := o.nonce(nonce, lastBlock); err != nil {
-		return nil, err
-	}
-	decrypted, err := o.aead.Open(out, nonce, block, o.additionalData)
-	if err != nil {
-		return nil, err
-	}
-	o.i++
-	o.additionalData = nil
-	return decrypted, nil
-}
-
-// An EncryptingWriter encrypts data in segments using the STREAM construction
-// described in https://eprint.iacr.org/2015/189.pdf. The writer buffers data up
-// to the segment size, so it's important to call Close to flush the
-// final segment.
-type EncryptingWriter struct {
-	w           io.Writer
-	oae2        oae2
-	segmentSize int
-
-	initialized bool
-	err         error
-	buf         []byte
-}
-
-type opts struct {
-	additionalData []byte
-	segmentSize    int
-}
-
-var defaultOpts = opts{segmentSize: 192*1024 - 1 - aeadOverhead}
-
-type Option func(*opts)
-
-func WithAdditionalData(ad []byte) Option {
-	return func(opts *opts) {
-		opts.additionalData = ad
-	}
-}
-
-func WithSegmentSize(segmentSize int) Option {
-	return func(opts *opts) {
-		opts.segmentSize = segmentSize
-	}
-}
-
-// NewWriter returns a new EncryptingWriter that writes to w. The additionalData
-// will be authenticated with the first segment, but is not written to w. The
-// same additional data must be provided when decrypting.
-func (k EncryptionKey) NewWriter(w io.Writer, options ...Option) *EncryptingWriter {
-	opts := defaultOpts
-	for _, o := range options {
-		o(&opts)
-	}
-	return &EncryptingWriter{
-		w: w,
-		oae2: oae2{
-			key:            k,
-			additionalData: opts.additionalData,
-		},
-		segmentSize: opts.segmentSize,
-	}
-}
-
-func (w *EncryptingWriter) initialize() error {
-	w.initialized = true
-	w.buf = make([]byte, 0, w.segmentSize+aeadOverhead)
-	header := make([]byte, headerSize)
-	rand.Read(header)
-	if w.err = w.oae2.initialize(header); w.err != nil {
-		return w.err
-	}
-	_, w.err = w.w.Write(header)
-	return w.err
-}
-
-func (w *EncryptingWriter) writeBuf() error {
-	var encrypted []byte
-	if encrypted, w.err = w.oae2.encryptBlock(w.buf[:0], w.buf, false); w.err != nil {
-		return w.err
-	}
-	if _, w.err = w.w.Write(encrypted); w.err != nil {
-		return w.err
-	}
-	w.buf = w.buf[:0]
-	return nil
-}
-
-func (w *EncryptingWriter) Write(buf []byte) (int, error) {
-	if !w.initialized {
-		if err := w.initialize(); err != nil {
-			return 0, err
-		}
-	}
-	if w.err != nil {
-		return 0, w.err
-	}
-	r := bytes.NewReader(buf)
-	nn := 0
-	for r.Len() > 0 {
-		if len(w.buf) == w.segmentSize {
-			if err := w.writeBuf(); err != nil {
-				return nn, err
-			}
-		}
-		n, _ := r.Read(w.buf[len(w.buf):w.segmentSize])
-		w.buf = w.buf[:len(w.buf)+n]
-		nn += n
-	}
-	return nn, nil
-}
-
-var errClosed = errors.New("closed")
-
-// Close encrypts writes the final segment. It does not close the
-// underlying writer.
-func (w *EncryptingWriter) Close() error {
-	if !w.initialized {
-		if err := w.initialize(); err != nil {
-			return err
-		}
-	}
-	if w.err == errClosed {
-		return nil
-	}
-	if w.err != nil {
-		return w.err
-	}
-	var encrypted []byte
-	if encrypted, w.err = w.oae2.encryptBlock(w.buf[:0], w.buf, true); w.err != nil {
-		return w.err
-	}
-	if _, w.err = w.w.Write(encrypted); w.err != nil {
-		return w.err
-	}
-	w.err = errClosed
-	return nil
-}
-
-// A DecryptingReader decrypts data using the STREAM construction.
-type DecryptingReader struct {
-	r           *bufio.Reader
-	oae2        oae2
-	segmentSize int
-
-	initialized bool
-	buf         bytes.Buffer
-}
-
-// NewReader returns a new DecryptingWriter that decrypts data from r. The
-// additionaData must be the same that was provided when encrypting.
-func (k EncryptionKey) NewReader(r io.Reader, options ...Option) *DecryptingReader {
-	opts := defaultOpts
-	for _, o := range options {
-		o(&opts)
-	}
-	return &DecryptingReader{
-		r: bufio.NewReaderSize(r, headerSize),
-		oae2: oae2{
-			key:            k,
-			additionalData: opts.additionalData,
-		},
-		segmentSize: opts.segmentSize,
-	}
-}
-
-func (r *DecryptingReader) initialize() error {
-	header, err := r.r.Peek(headerSize)
-	if err != nil {
-		return err
-	}
-	if err := r.oae2.initialize(header); err != nil {
-		return err
-	}
-	r.r.Discard(len(header))
-	r.buf = *bytes.NewBuffer(make([]byte, 0, r.segmentSize+aeadOverhead))
-	r.initialized = true
-	return nil
-}
-
-func (r *DecryptingReader) fillBuf() error {
-	r.buf.Reset()
-	buf := r.buf.AvailableBuffer()
-	buf = buf[:cap(buf)]
-	n, err := io.ReadFull(r.r, buf)
-	if n == 0 {
-		if err == io.ErrUnexpectedEOF {
-			return io.EOF
-		}
-		return err
-	}
-	buf = buf[:n]
-	if n > 0 {
-		// Peek one extra byte to check if this is the last segment
-		_, readErr := r.r.Peek(1)
-		result, err := r.oae2.decryptBlock(buf[:0], buf, readErr == io.EOF)
-		if err != nil {
-			return err
-		}
-		r.buf.Write(result)
-	}
-	return nil
-}
-
-func (r *DecryptingReader) Read(buf []byte) (int, error) {
-	if !r.initialized {
-		if err := r.initialize(); err != nil {
-			return 0, err
-		}
-	}
-	if r.buf.Len() == 0 {
-		if err := r.fillBuf(); err != nil {
-			return 0, err
-		}
-	}
-	n, _ := r.buf.Read(buf)
-	return n, nil
-}