added fs encryption overlay

vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305.go

@@ -0,0 +1,98 @@
+// Copyright 2016 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 chacha20poly1305 implements the ChaCha20-Poly1305 AEAD and its
+// extended nonce variant XChaCha20-Poly1305, as specified in RFC 8439 and
+// draft-irtf-cfrg-xchacha-01.
+package chacha20poly1305 // import "golang.org/x/crypto/chacha20poly1305"
+
+import (
+	"crypto/cipher"
+	"errors"
+)
+
+const (
+	// KeySize is the size of the key used by this AEAD, in bytes.
+	KeySize = 32
+
+	// NonceSize is the size of the nonce used with the standard variant of this
+	// AEAD, in bytes.
+	//
+	// Note that this is too short to be safely generated at random if the same
+	// key is reused more than 2³² times.
+	NonceSize = 12
+
+	// NonceSizeX is the size of the nonce used with the XChaCha20-Poly1305
+	// variant of this AEAD, in bytes.
+	NonceSizeX = 24
+
+	// Overhead is the size of the Poly1305 authentication tag, and the
+	// difference between a ciphertext length and its plaintext.
+	Overhead = 16
+)
+
+type chacha20poly1305 struct {
+	key [KeySize]byte
+}
+
+// New returns a ChaCha20-Poly1305 AEAD that uses the given 256-bit key.
+func New(key []byte) (cipher.AEAD, error) {
+	if len(key) != KeySize {
+		return nil, errors.New("chacha20poly1305: bad key length")
+	}
+	ret := new(chacha20poly1305)
+	copy(ret.key[:], key)
+	return ret, nil
+}
+
+func (c *chacha20poly1305) NonceSize() int {
+	return NonceSize
+}
+
+func (c *chacha20poly1305) Overhead() int {
+	return Overhead
+}
+
+func (c *chacha20poly1305) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
+	if len(nonce) != NonceSize {
+		panic("chacha20poly1305: bad nonce length passed to Seal")
+	}
+
+	if uint64(len(plaintext)) > (1<<38)-64 {
+		panic("chacha20poly1305: plaintext too large")
+	}
+
+	return c.seal(dst, nonce, plaintext, additionalData)
+}
+
+var errOpen = errors.New("chacha20poly1305: message authentication failed")
+
+func (c *chacha20poly1305) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	if len(nonce) != NonceSize {
+		panic("chacha20poly1305: bad nonce length passed to Open")
+	}
+	if len(ciphertext) < 16 {
+		return nil, errOpen
+	}
+	if uint64(len(ciphertext)) > (1<<38)-48 {
+		panic("chacha20poly1305: ciphertext too large")
+	}
+
+	return c.open(dst, nonce, ciphertext, additionalData)
+}
+
+// sliceForAppend takes a slice and a requested number of bytes. It returns a
+// slice with the contents of the given slice followed by that many bytes and a
+// second slice that aliases into it and contains only the extra bytes. If the
+// original slice has sufficient capacity then no allocation is performed.
+func sliceForAppend(in []byte, n int) (head, tail []byte) {
+	if total := len(in) + n; cap(in) >= total {
+		head = in[:total]
+	} else {
+		head = make([]byte, total)
+		copy(head, in)
+	}
+	tail = head[len(in):]
+	return
+}

vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go

@@ -0,0 +1,87 @@
+// Copyright 2016 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.
+
+//go:build gc && !purego
+// +build gc,!purego
+
+package chacha20poly1305
+
+import (
+	"encoding/binary"
+
+	"golang.org/x/crypto/internal/subtle"
+	"golang.org/x/sys/cpu"
+)
+
+//go:noescape
+func chacha20Poly1305Open(dst []byte, key []uint32, src, ad []byte) bool
+
+//go:noescape
+func chacha20Poly1305Seal(dst []byte, key []uint32, src, ad []byte)
+
+var (
+	useAVX2 = cpu.X86.HasAVX2 && cpu.X86.HasBMI2
+)
+
+// setupState writes a ChaCha20 input matrix to state. See
+// https://tools.ietf.org/html/rfc7539#section-2.3.
+func setupState(state *[16]uint32, key *[32]byte, nonce []byte) {
+	state[0] = 0x61707865
+	state[1] = 0x3320646e
+	state[2] = 0x79622d32
+	state[3] = 0x6b206574
+
+	state[4] = binary.LittleEndian.Uint32(key[0:4])
+	state[5] = binary.LittleEndian.Uint32(key[4:8])
+	state[6] = binary.LittleEndian.Uint32(key[8:12])
+	state[7] = binary.LittleEndian.Uint32(key[12:16])
+	state[8] = binary.LittleEndian.Uint32(key[16:20])
+	state[9] = binary.LittleEndian.Uint32(key[20:24])
+	state[10] = binary.LittleEndian.Uint32(key[24:28])
+	state[11] = binary.LittleEndian.Uint32(key[28:32])
+
+	state[12] = 0
+	state[13] = binary.LittleEndian.Uint32(nonce[0:4])
+	state[14] = binary.LittleEndian.Uint32(nonce[4:8])
+	state[15] = binary.LittleEndian.Uint32(nonce[8:12])
+}
+
+func (c *chacha20poly1305) seal(dst, nonce, plaintext, additionalData []byte) []byte {
+	if !cpu.X86.HasSSSE3 {
+		return c.sealGeneric(dst, nonce, plaintext, additionalData)
+	}
+
+	var state [16]uint32
+	setupState(&state, &c.key, nonce)
+
+	ret, out := sliceForAppend(dst, len(plaintext)+16)
+	if subtle.InexactOverlap(out, plaintext) {
+		panic("chacha20poly1305: invalid buffer overlap")
+	}
+	chacha20Poly1305Seal(out[:], state[:], plaintext, additionalData)
+	return ret
+}
+
+func (c *chacha20poly1305) open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	if !cpu.X86.HasSSSE3 {
+		return c.openGeneric(dst, nonce, ciphertext, additionalData)
+	}
+
+	var state [16]uint32
+	setupState(&state, &c.key, nonce)
+
+	ciphertext = ciphertext[:len(ciphertext)-16]
+	ret, out := sliceForAppend(dst, len(ciphertext))
+	if subtle.InexactOverlap(out, ciphertext) {
+		panic("chacha20poly1305: invalid buffer overlap")
+	}
+	if !chacha20Poly1305Open(out, state[:], ciphertext, additionalData) {
+		for i := range out {
+			out[i] = 0
+		}
+		return nil, errOpen
+	}
+
+	return ret, nil
+}

vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go

@@ -0,0 +1,81 @@
+// Copyright 2016 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 chacha20poly1305
+
+import (
+	"encoding/binary"
+
+	"golang.org/x/crypto/chacha20"
+	"golang.org/x/crypto/internal/poly1305"
+	"golang.org/x/crypto/internal/subtle"
+)
+
+func writeWithPadding(p *poly1305.MAC, b []byte) {
+	p.Write(b)
+	if rem := len(b) % 16; rem != 0 {
+		var buf [16]byte
+		padLen := 16 - rem
+		p.Write(buf[:padLen])
+	}
+}
+
+func writeUint64(p *poly1305.MAC, n int) {
+	var buf [8]byte
+	binary.LittleEndian.PutUint64(buf[:], uint64(n))
+	p.Write(buf[:])
+}
+
+func (c *chacha20poly1305) sealGeneric(dst, nonce, plaintext, additionalData []byte) []byte {
+	ret, out := sliceForAppend(dst, len(plaintext)+poly1305.TagSize)
+	ciphertext, tag := out[:len(plaintext)], out[len(plaintext):]
+	if subtle.InexactOverlap(out, plaintext) {
+		panic("chacha20poly1305: invalid buffer overlap")
+	}
+
+	var polyKey [32]byte
+	s, _ := chacha20.NewUnauthenticatedCipher(c.key[:], nonce)
+	s.XORKeyStream(polyKey[:], polyKey[:])
+	s.SetCounter(1) // set the counter to 1, skipping 32 bytes
+	s.XORKeyStream(ciphertext, plaintext)
+
+	p := poly1305.New(&polyKey)
+	writeWithPadding(p, additionalData)
+	writeWithPadding(p, ciphertext)
+	writeUint64(p, len(additionalData))
+	writeUint64(p, len(plaintext))
+	p.Sum(tag[:0])
+
+	return ret
+}
+
+func (c *chacha20poly1305) openGeneric(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	tag := ciphertext[len(ciphertext)-16:]
+	ciphertext = ciphertext[:len(ciphertext)-16]
+
+	var polyKey [32]byte
+	s, _ := chacha20.NewUnauthenticatedCipher(c.key[:], nonce)
+	s.XORKeyStream(polyKey[:], polyKey[:])
+	s.SetCounter(1) // set the counter to 1, skipping 32 bytes
+
+	p := poly1305.New(&polyKey)
+	writeWithPadding(p, additionalData)
+	writeWithPadding(p, ciphertext)
+	writeUint64(p, len(additionalData))
+	writeUint64(p, len(ciphertext))
+
+	ret, out := sliceForAppend(dst, len(ciphertext))
+	if subtle.InexactOverlap(out, ciphertext) {
+		panic("chacha20poly1305: invalid buffer overlap")
+	}
+	if !p.Verify(tag) {
+		for i := range out {
+			out[i] = 0
+		}
+		return nil, errOpen
+	}
+
+	s.XORKeyStream(out, ciphertext)
+	return ret, nil
+}

vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_noasm.go

@@ -0,0 +1,16 @@
+// Copyright 2016 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.
+
+//go:build !amd64 || !gc || purego
+// +build !amd64 !gc purego
+
+package chacha20poly1305
+
+func (c *chacha20poly1305) seal(dst, nonce, plaintext, additionalData []byte) []byte {
+	return c.sealGeneric(dst, nonce, plaintext, additionalData)
+}
+
+func (c *chacha20poly1305) open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	return c.openGeneric(dst, nonce, ciphertext, additionalData)
+}

vendor/golang.org/x/crypto/chacha20poly1305/xchacha20poly1305.go

@@ -0,0 +1,86 @@
+// Copyright 2018 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 chacha20poly1305
+
+import (
+	"crypto/cipher"
+	"errors"
+
+	"golang.org/x/crypto/chacha20"
+)
+
+type xchacha20poly1305 struct {
+	key [KeySize]byte
+}
+
+// NewX returns a XChaCha20-Poly1305 AEAD that uses the given 256-bit key.
+//
+// XChaCha20-Poly1305 is a ChaCha20-Poly1305 variant that takes a longer nonce,
+// suitable to be generated randomly without risk of collisions. It should be
+// preferred when nonce uniqueness cannot be trivially ensured, or whenever
+// nonces are randomly generated.
+func NewX(key []byte) (cipher.AEAD, error) {
+	if len(key) != KeySize {
+		return nil, errors.New("chacha20poly1305: bad key length")
+	}
+	ret := new(xchacha20poly1305)
+	copy(ret.key[:], key)
+	return ret, nil
+}
+
+func (*xchacha20poly1305) NonceSize() int {
+	return NonceSizeX
+}
+
+func (*xchacha20poly1305) Overhead() int {
+	return Overhead
+}
+
+func (x *xchacha20poly1305) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
+	if len(nonce) != NonceSizeX {
+		panic("chacha20poly1305: bad nonce length passed to Seal")
+	}
+
+	// XChaCha20-Poly1305 technically supports a 64-bit counter, so there is no
+	// size limit. However, since we reuse the ChaCha20-Poly1305 implementation,
+	// the second half of the counter is not available. This is unlikely to be
+	// an issue because the cipher.AEAD API requires the entire message to be in
+	// memory, and the counter overflows at 256 GB.
+	if uint64(len(plaintext)) > (1<<38)-64 {
+		panic("chacha20poly1305: plaintext too large")
+	}
+
+	c := new(chacha20poly1305)
+	hKey, _ := chacha20.HChaCha20(x.key[:], nonce[0:16])
+	copy(c.key[:], hKey)
+
+	// The first 4 bytes of the final nonce are unused counter space.
+	cNonce := make([]byte, NonceSize)
+	copy(cNonce[4:12], nonce[16:24])
+
+	return c.seal(dst, cNonce[:], plaintext, additionalData)
+}
+
+func (x *xchacha20poly1305) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	if len(nonce) != NonceSizeX {
+		panic("chacha20poly1305: bad nonce length passed to Open")
+	}
+	if len(ciphertext) < 16 {
+		return nil, errOpen
+	}
+	if uint64(len(ciphertext)) > (1<<38)-48 {
+		panic("chacha20poly1305: ciphertext too large")
+	}
+
+	c := new(chacha20poly1305)
+	hKey, _ := chacha20.HChaCha20(x.key[:], nonce[0:16])
+	copy(c.key[:], hKey)
+
+	// The first 4 bytes of the final nonce are unused counter space.
+	cNonce := make([]byte, NonceSize)
+	copy(cNonce[4:12], nonce[16:24])
+
+	return c.open(dst, cNonce[:], ciphertext, additionalData)
+}

vendor/golang.org/x/crypto/hkdf/hkdf.go

@@ -0,0 +1,93 @@
+// Copyright 2014 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 hkdf implements the HMAC-based Extract-and-Expand Key Derivation
+// Function (HKDF) as defined in RFC 5869.
+//
+// HKDF is a cryptographic key derivation function (KDF) with the goal of
+// expanding limited input keying material into one or more cryptographically
+// strong secret keys.
+package hkdf // import "golang.org/x/crypto/hkdf"
+
+import (
+	"crypto/hmac"
+	"errors"
+	"hash"
+	"io"
+)
+
+// Extract generates a pseudorandom key for use with Expand from an input secret
+// and an optional independent salt.
+//
+// Only use this function if you need to reuse the extracted key with multiple
+// Expand invocations and different context values. Most common scenarios,
+// including the generation of multiple keys, should use New instead.
+func Extract(hash func() hash.Hash, secret, salt []byte) []byte {
+	if salt == nil {
+		salt = make([]byte, hash().Size())
+	}
+	extractor := hmac.New(hash, salt)
+	extractor.Write(secret)
+	return extractor.Sum(nil)
+}
+
+type hkdf struct {
+	expander hash.Hash
+	size     int
+
+	info    []byte
+	counter byte
+
+	prev []byte
+	buf  []byte
+}
+
+func (f *hkdf) Read(p []byte) (int, error) {
+	// Check whether enough data can be generated
+	need := len(p)
+	remains := len(f.buf) + int(255-f.counter+1)*f.size
+	if remains < need {
+		return 0, errors.New("hkdf: entropy limit reached")
+	}
+	// Read any leftover from the buffer
+	n := copy(p, f.buf)
+	p = p[n:]
+
+	// Fill the rest of the buffer
+	for len(p) > 0 {
+		f.expander.Reset()
+		f.expander.Write(f.prev)
+		f.expander.Write(f.info)
+		f.expander.Write([]byte{f.counter})
+		f.prev = f.expander.Sum(f.prev[:0])
+		f.counter++
+
+		// Copy the new batch into p
+		f.buf = f.prev
+		n = copy(p, f.buf)
+		p = p[n:]
+	}
+	// Save leftovers for next run
+	f.buf = f.buf[n:]
+
+	return need, nil
+}
+
+// Expand returns a Reader, from which keys can be read, using the given
+// pseudorandom key and optional context info, skipping the extraction step.
+//
+// The pseudorandomKey should have been generated by Extract, or be a uniformly
+// random or pseudorandom cryptographically strong key. See RFC 5869, Section
+// 3.3. Most common scenarios will want to use New instead.
+func Expand(hash func() hash.Hash, pseudorandomKey, info []byte) io.Reader {
+	expander := hmac.New(hash, pseudorandomKey)
+	return &hkdf{expander, expander.Size(), info, 1, nil, nil}
+}
+
+// New returns a Reader, from which keys can be read, using the given hash,
+// secret, salt and context info. Salt and info can be nil.
+func New(hash func() hash.Hash, secret, salt, info []byte) io.Reader {
+	prk := Extract(hash, secret, salt)
+	return Expand(hash, prk, info)
+}

vendor/modules.txt

@@ -12,9 +12,11 @@ github.com/pkg/sftp/internal/encoding/ssh/filexfer
 ## explicit; go 1.17
 golang.org/x/crypto/blowfish
 golang.org/x/crypto/chacha20
+golang.org/x/crypto/chacha20poly1305
 golang.org/x/crypto/curve25519
 golang.org/x/crypto/curve25519/internal/field
 golang.org/x/crypto/ed25519
+golang.org/x/crypto/hkdf
 golang.org/x/crypto/internal/poly1305
 golang.org/x/crypto/internal/subtle
 golang.org/x/crypto/ssh