initial encrypted zone support

aes.go

@@ -0,0 +1,68 @@
+package hdfs
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	// in FileWriter we use chunks upto aesChunkSize bytes to encrypt data
+	aesChunkSize = 1024 * 1024
+)
+
+// calculateIV `shifts` IV to given offset
+// based on calculateIV from AesCtrCryptoCodec.java
+func calculateIV(offset int64, initIV []byte) ([]byte, error) {
+	if len(initIV) != aes.BlockSize {
+		return nil, fmt.Errorf("calculateIV: invalid iv size: %v", len(initIV))
+	}
+
+	counter := offset / aes.BlockSize
+	iv := make([]byte, aes.BlockSize)
+
+	high := binary.BigEndian.Uint64(initIV[:8])
+	low := binary.BigEndian.Uint64(initIV[8:])
+	origLow := low
+
+	low += uint64(counter)
+	if low < origLow { // wrap
+		high += 1
+	}
+
+	binary.BigEndian.PutUint64(iv, high)
+	binary.BigEndian.PutUint64(iv[8:], low)
+
+	return iv, nil
+}
+
+// aesCtrStep perform AES-CTR XOR operation on given byte string.
+// Once encryption and decryption are exactly the same operation for CTR mode,
+// this function can be used to perform both.
+func aesCtrStep(offset int64, enc *TransparentEncryptionInfo, b []byte) ([]byte, error) {
+	iv, err := calculateIV(offset, enc.iv)
+	if err != nil {
+		return nil, err
+	}
+
+	if enc.cipher == nil {
+		cipher, err := aes.NewCipher(enc.key)
+		if err != nil {
+			return nil, err
+		}
+		enc.cipher = cipher
+	}
+
+	stream := cipher.NewCTR(enc.cipher, iv)
+
+	padding := offset % aes.BlockSize
+	if padding > 0 {
+		tmp := make([]byte, padding)
+		stream.XORKeyStream(tmp, tmp)
+	}
+
+	text := make([]byte, len(b))
+	stream.XORKeyStream(text, b)
+	return text, nil
+}

aes_test.go

@@ -0,0 +1,50 @@
+package hdfs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAesChunks(t *testing.T) {
+	originalText := []byte("some random plain text, nice to have it quite long")
+	key := []byte("0123456789abcdef")
+
+	// Choose iv to hit counter overflow.
+	iv := []byte("\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\xff\xf5")
+	enc := &TransparentEncryptionInfo{iv: iv, key: key}
+
+	// Ensure that we can decrypt text after encryption.
+	// In CTR mode, implementation for `encrypt` and `decrypt` actually the same
+	// since we just XOR on input.
+	encryptedText, err := aesCtrStep(0, enc, originalText)
+	assert.Equal(t, err, nil)
+	decryptedText, err := aesCtrStep(0, enc, encryptedText)
+	assert.Equal(t, err, nil)
+	assert.Equal(t, originalText, decryptedText)
+
+	// CTR mode allow us to encrypt/decrypt string by chunks
+	// (using correct offset from start of string).
+	// Ensure that result equal to one, produced in one step.
+	encryptedByChunks := make([]byte, 0)
+	var pos int64 = 0
+	for _, x := range []int{5, 7, 6, 4, 28} {
+		tmp, err := aesCtrStep(pos, enc, originalText[pos:pos+int64(x)])
+		assert.Equal(t, err, nil)
+		encryptedByChunks = append(encryptedByChunks, tmp...)
+		pos += int64(x)
+	}
+	assert.Equal(t, encryptedByChunks, encryptedText)
+
+	// Decrypt string by chunks.
+	// Ensure that result equal to one, produced in one step.
+	decryptedByChunks := make([]byte, 0)
+	pos = 0
+	for _, x := range []int{5, 7, 6, 4, 28} {
+		tmp, err := aesCtrStep(pos, enc, encryptedText[pos:pos+int64(x)])
+		assert.Equal(t, err, nil)
+		decryptedByChunks = append(decryptedByChunks, tmp...)
+		pos += int64(x)
+	}
+	assert.Equal(t, decryptedByChunks, originalText)
+}

client.go

@@ -6,6 +6,8 @@ import (
 	"io"
 	"io/ioutil"
 	"net"
+	"net/http"
+	"net/http/cookiejar"
 	"os"
 	"os/user"
 	"sort"
@@ -36,6 +38,8 @@ type Client struct {
 
 	defaults      *hdfs.FsServerDefaultsProto
 	encryptionKey *hdfs.DataEncryptionKeyProto
+
+	http *http.Client
 }
 
 // ClientOptions represents the configurable options for a client.
@@ -203,7 +207,16 @@ func NewClient(options ClientOptions) (*Client, error) {
 		return nil, err
 	}
 
-	return &Client{namenode: namenode, options: options}, nil
+	// We need cookies to access KMS (required for HDFS encrypted zone).
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, errors.New("cant create cookie jar")
+	}
+
+	// Not extending ClientOptions to preserve compatibility, so timeouts not configured.
+	http := &http.Client{Jar: jar}
+
+	return &Client{namenode: namenode, options: options, http: http}, nil
 }
 
 // New returns Client connected to the namenode(s) specified by address, or an

file_reader.go

@@ -1,6 +1,7 @@
 package hdfs
 
 import (
+	"crypto/cipher"
 	"crypto/md5"
 	"errors"
 	"fmt"
@@ -29,6 +30,16 @@ type FileReader struct {
 	readdirLast string
 
 	closed bool
+
+	// encryption
+	enc *TransparentEncryptionInfo
+}
+
+// A TransparentEncryptionInfo is a key and iv to encrypt or decrypt file data
+type TransparentEncryptionInfo struct {
+	key    []byte
+	iv     []byte
+	cipher cipher.Block
 }
 
 // Open returns an FileReader which can be used for reading.
@@ -38,11 +49,25 @@ func (c *Client) Open(name string) (*FileReader, error) {
 		return nil, &os.PathError{"open", name, interpretException(err)}
 	}
 
+	status, ok := info.Sys().(*FileStatus)
+	if !ok {
+		return nil, &os.PathError{"open", name, errors.New("internal error: fail to access file status")}
+	}
+
+	var enc *TransparentEncryptionInfo
+	if status.FileEncryptionInfo != nil {
+		enc, err = c.kmsGetKey(status.FileEncryptionInfo)
+		if err != nil {
+			return nil, &os.PathError{"open", name, err}
+		}
+	}
+
 	return &FileReader{
 		client: c,
 		name:   name,
 		info:   info,
 		closed: false,
+		enc:    enc,
 	}, nil
 }
 
@@ -184,6 +209,25 @@ func (f *FileReader) Read(b []byte) (int, error) {
 		return 0, io.ErrClosedPipe
 	}
 
+	offset := f.offset
+	n, err := f.readImpl(b)
+
+	// Decrypt data chunk if file from HDFS encrypted zone.
+	if f.enc != nil && n > 0 {
+		plaintext, err := aesCtrStep(offset, f.enc, b[:n])
+		if err != nil {
+			f.offset = offset
+			return 0, err
+		}
+		for i := 0; i < n; i++ {
+			b[i] = plaintext[i]
+		}
+	}
+
+	return n, err
+}
+
+func (f *FileReader) readImpl(b []byte) (int, error) {
 	if f.info.IsDir() {
 		return 0, &os.PathError{
 			"read",

file_writer.go

@@ -27,9 +27,13 @@ type FileWriter struct {
 	name        string
 	replication int
 	blockSize   int64
+	offset      int64
 
 	blockWriter *transfer.BlockWriter
 	deadline    time.Time
+
+	// Key and IV for transparent encryption support.
+	enc *TransparentEncryptionInfo
 }
 
 // Create opens a new file in HDFS with the default replication, block size,
@@ -62,13 +66,14 @@ func (c *Client) Create(name string) (*FileWriter, error) {
 // very important that Close is called after all data has been written.
 func (c *Client) CreateFile(name string, replication int, blockSize int64, perm os.FileMode) (*FileWriter, error) {
 	createReq := &hdfs.CreateRequestProto{
-		Src:          proto.String(name),
-		Masked:       &hdfs.FsPermissionProto{Perm: proto.Uint32(uint32(perm))},
-		ClientName:   proto.String(c.namenode.ClientName),
-		CreateFlag:   proto.Uint32(1),
-		CreateParent: proto.Bool(false),
-		Replication:  proto.Uint32(uint32(replication)),
-		BlockSize:    proto.Uint64(uint64(blockSize)),
+		Src:                   proto.String(name),
+		Masked:                &hdfs.FsPermissionProto{Perm: proto.Uint32(uint32(perm))},
+		ClientName:            proto.String(c.namenode.ClientName),
+		CreateFlag:            proto.Uint32(1),
+		CreateParent:          proto.Bool(false),
+		Replication:           proto.Uint32(uint32(replication)),
+		BlockSize:             proto.Uint64(uint64(blockSize)),
+		CryptoProtocolVersion: []hdfs.CryptoProtocolVersionProto{hdfs.CryptoProtocolVersionProto_ENCRYPTION_ZONES},
 	}
 	createResp := &hdfs.CreateResponseProto{}
 
@@ -77,11 +82,21 @@ func (c *Client) CreateFile(name string, replication int, blockSize int64, perm
 		return nil, &os.PathError{"create", name, interpretCreateException(err)}
 	}
 
+	var enc *TransparentEncryptionInfo
+	if createResp.GetFs().GetFileEncryptionInfo() != nil {
+		enc, err = c.kmsGetKey(createResp.GetFs().GetFileEncryptionInfo())
+		if err != nil {
+			c.Remove(name)
+			return nil, &os.PathError{"create", name, err}
+		}
+	}
+
 	return &FileWriter{
 		client:      c,
 		name:        name,
 		replication: replication,
 		blockSize:   blockSize,
+		enc:         enc,
 	}, nil
 }
 
@@ -106,11 +121,21 @@ func (c *Client) Append(name string) (*FileWriter, error) {
 		return nil, &os.PathError{"append", name, interpretException(err)}
 	}
 
+	var enc *TransparentEncryptionInfo
+	if appendResp.GetStat().GetFileEncryptionInfo() != nil {
+		enc, err = c.kmsGetKey(appendResp.GetStat().GetFileEncryptionInfo())
+		if err != nil {
+			return nil, &os.PathError{"append", name, err}
+		}
+	}
+
 	f := &FileWriter{
 		client:      c,
 		name:        name,
 		replication: int(appendResp.Stat.GetBlockReplication()),
 		blockSize:   int64(appendResp.Stat.GetBlocksize()),
+		offset:      int64(*appendResp.Stat.Length),
+		enc:         enc,
 	}
 
 	// This returns nil if there are no blocks (it's an empty file) or if the
@@ -176,6 +201,28 @@ func (f *FileWriter) SetDeadline(t time.Time) error {
 // of this, it is important that Close is called after all data has been
 // written.
 func (f *FileWriter) Write(b []byte) (int, error) {
+	// Encrypt data chunk if file in HDFS encrypted zone.
+	if f.enc != nil && len(b) > 0 {
+		var offset int
+		for offset < len(b) {
+			size := min(len(b)-offset, aesChunkSize)
+			ciphertext, err := aesCtrStep(f.offset, f.enc, b[offset:offset+size])
+			if err != nil {
+				return offset, err
+			}
+			writtenSize, err := f.writeImpl(ciphertext)
+			offset += writtenSize
+			if err != nil {
+				return offset, err
+			}
+		}
+		return offset, nil
+	} else {
+		return f.writeImpl(b)
+	}
+}
+
+func (f *FileWriter) writeImpl(b []byte) (int, error) {
 	if f.blockWriter == nil {
 		err := f.startNewBlock()
 		if err != nil {
@@ -187,6 +234,7 @@ func (f *FileWriter) Write(b []byte) (int, error) {
 	for off < len(b) {
 		n, err := f.blockWriter.Write(b[off:])
 		off += n
+		f.offset += int64(n)
 		if err == transfer.ErrEndOfBlock {
 			err = f.startNewBlock()
 		}
@@ -316,3 +364,10 @@ func (f *FileWriter) finalizeBlock() error {
 	f.blockWriter = nil
 	return nil
 }
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/jcmturner/gofork v1.0.0 // indirect
 	github.com/jcmturner/goidentity/v6 v6.0.1 // indirect
 	github.com/jcmturner/rpc/v2 v2.0.3 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/crypto v0.0.0-20201112155050-0c6587e931a9 // indirect
 	golang.org/x/net v0.0.0-20200114155413-6afb5195e5aa // indirect

go.sum

@@ -23,6 +23,8 @@ github.com/jcmturner/rpc/v2 v2.0.3 h1:7FXXj8Ti1IaVFpSAziCZWNzbNuZmnvw/i6CqLNdWfZ
 github.com/jcmturner/rpc/v2 v2.0.3/go.mod h1:VUJYCIDm3PVOEHw8sgt091/20OJjskO/YJki3ELg/Hc=
 github.com/pborman/getopt v1.1.0 h1:eJ3aFZroQqq0bWmraivjQNt6Dmm5M0h2JcDW38/Azb0=
 github.com/pborman/getopt v1.1.0/go.mod h1:FxXoW1Re00sQG/+KIkuSqRL/LwQgSkv7uyac+STFsbk=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=