1 files changed, 284 insertions, 0 deletions
diff --git a/vendor/github.com/minio/minio-go/pkg/encrypt/cbc.go b/vendor/github.com/minio/minio-go/pkg/encrypt/cbc.go
new file mode 100644
index 000000000..7670e68f4
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/pkg/encrypt/cbc.go
@@ -0,0 +1,284 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package encrypt
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"io"
+)
+
+// Crypt mode - encryption or decryption
+type cryptMode int
+
+const (
+	encryptMode cryptMode = iota
+	decryptMode
+)
+
+// CBCSecureMaterials encrypts/decrypts data using AES CBC algorithm
+type CBCSecureMaterials struct {
+
+	// Data stream to encrypt/decrypt
+	stream io.Reader
+
+	// Last internal error
+	err error
+
+	// End of file reached
+	eof bool
+
+	// Holds initial data
+	srcBuf *bytes.Buffer
+
+	// Holds transformed data (encrypted or decrypted)
+	dstBuf *bytes.Buffer
+
+	// Encryption algorithm
+	encryptionKey Key
+
+	// Key to encrypts/decrypts data
+	contentKey []byte
+
+	// Encrypted form of contentKey
+	cryptedKey []byte
+
+	// Initialization vector
+	iv []byte
+
+	// matDesc - currently unused
+	matDesc []byte
+
+	// Indicate if we are going to encrypt or decrypt
+	cryptMode cryptMode
+
+	// Helper that encrypts/decrypts data
+	blockMode cipher.BlockMode
+}
+
+// NewCBCSecureMaterials builds new CBC crypter module with
+// the specified encryption key (symmetric or asymmetric)
+func NewCBCSecureMaterials(key Key) (*CBCSecureMaterials, error) {
+	if key == nil {
+		return nil, errors.New("Unable to recognize empty encryption properties")
+	}
+	return &CBCSecureMaterials{
+		srcBuf:        bytes.NewBuffer([]byte{}),
+		dstBuf:        bytes.NewBuffer([]byte{}),
+		encryptionKey: key,
+		matDesc:       []byte("{}"),
+	}, nil
+
+}
+
+// SetupEncryptMode - tells CBC that we are going to encrypt data
+func (s *CBCSecureMaterials) SetupEncryptMode(stream io.Reader) error {
+	// Set mode to encrypt
+	s.cryptMode = encryptMode
+
+	// Set underlying reader
+	s.stream = stream
+
+	s.eof = false
+	s.srcBuf.Reset()
+	s.dstBuf.Reset()
+
+	var err error
+
+	// Generate random content key
+	s.contentKey = make([]byte, aes.BlockSize*2)
+	if _, err := rand.Read(s.contentKey); err != nil {
+		return err
+	}
+	// Encrypt content key
+	s.cryptedKey, err = s.encryptionKey.Encrypt(s.contentKey)
+	if err != nil {
+		return err
+	}
+	// Generate random IV
+	s.iv = make([]byte, aes.BlockSize)
+	if _, err = rand.Read(s.iv); err != nil {
+		return err
+	}
+	// New cipher
+	encryptContentBlock, err := aes.NewCipher(s.contentKey)
+	if err != nil {
+		return err
+	}
+
+	s.blockMode = cipher.NewCBCEncrypter(encryptContentBlock, s.iv)
+
+	return nil
+}
+
+// SetupDecryptMode - tells CBC that we are going to decrypt data
+func (s *CBCSecureMaterials) SetupDecryptMode(stream io.Reader, iv string, key string) error {
+	// Set mode to decrypt
+	s.cryptMode = decryptMode
+
+	// Set underlying reader
+	s.stream = stream
+
+	// Reset
+	s.eof = false
+	s.srcBuf.Reset()
+	s.dstBuf.Reset()
+
+	var err error
+
+	// Get IV
+	s.iv, err = base64.StdEncoding.DecodeString(iv)
+	if err != nil {
+		return err
+	}
+
+	// Get encrypted content key
+	s.cryptedKey, err = base64.StdEncoding.DecodeString(key)
+	if err != nil {
+		return err
+	}
+
+	// Decrypt content key
+	s.contentKey, err = s.encryptionKey.Decrypt(s.cryptedKey)
+	if err != nil {
+		return err
+	}
+
+	// New cipher
+	decryptContentBlock, err := aes.NewCipher(s.contentKey)
+	if err != nil {
+		return err
+	}
+
+	s.blockMode = cipher.NewCBCDecrypter(decryptContentBlock, s.iv)
+	return nil
+}
+
+// GetIV - return randomly generated IV (per S3 object), base64 encoded.
+func (s *CBCSecureMaterials) GetIV() string {
+	return base64.StdEncoding.EncodeToString(s.iv)
+}
+
+// GetKey - return content encrypting key (cek) in encrypted form, base64 encoded.
+func (s *CBCSecureMaterials) GetKey() string {
+	return base64.StdEncoding.EncodeToString(s.cryptedKey)
+}
+
+// GetDesc - user provided encryption material description in JSON (UTF8) format.
+func (s *CBCSecureMaterials) GetDesc() string {
+	return string(s.matDesc)
+}
+
+// Fill buf with encrypted/decrypted data
+func (s *CBCSecureMaterials) Read(buf []byte) (n int, err error) {
+	// Always fill buf from bufChunk at the end of this function
+	defer func() {
+		if s.err != nil {
+			n, err = 0, s.err
+		} else {
+			n, err = s.dstBuf.Read(buf)
+		}
+	}()
+
+	// Return
+	if s.eof {
+		return
+	}
+
+	// Fill dest buffer if its length is less than buf
+	for !s.eof && s.dstBuf.Len() < len(buf) {
+
+		srcPart := make([]byte, aes.BlockSize)
+		dstPart := make([]byte, aes.BlockSize)
+
+		// Fill src buffer
+		for s.srcBuf.Len() < aes.BlockSize*2 {
+			_, err = io.CopyN(s.srcBuf, s.stream, aes.BlockSize)
+			if err != nil {
+				break
+			}
+		}
+
+		// Quit immediately for errors other than io.EOF
+		if err != nil && err != io.EOF {
+			s.err = err
+			return
+		}
+
+		// Mark current encrypting/decrypting as finished
+		s.eof = (err == io.EOF)
+
+		if s.eof && s.cryptMode == encryptMode {
+			if srcPart, err = pkcs5Pad(s.srcBuf.Bytes(), aes.BlockSize); err != nil {
+				s.err = err
+				return
+			}
+		} else {
+			_, _ = s.srcBuf.Read(srcPart)
+		}
+
+		// Crypt srcPart content
+		for len(srcPart) > 0 {
+
+			// Crypt current part
+			s.blockMode.CryptBlocks(dstPart, srcPart[:aes.BlockSize])
+
+			// Unpad when this is the last part and we are decrypting
+			if s.eof && s.cryptMode == decryptMode {
+				dstPart, err = pkcs5Unpad(dstPart, aes.BlockSize)
+				if err != nil {
+					s.err = err
+					return
+				}
+			}
+
+			// Send crypted data to dstBuf
+			if _, wErr := s.dstBuf.Write(dstPart); wErr != nil {
+				s.err = wErr
+				return
+			}
+			// Move to the next part
+			srcPart = srcPart[aes.BlockSize:]
+		}
+	}
+	return
+}
+
+// Unpad a set of bytes following PKCS5 algorithm
+func pkcs5Unpad(buf []byte, blockSize int) ([]byte, error) {
+	len := len(buf)
+	if len == 0 {
+		return nil, errors.New("buffer is empty")
+	}
+	pad := int(buf[len-1])
+	if pad > len || pad > blockSize {
+		return nil, errors.New("invalid padding size")
+	}
+	return buf[:len-pad], nil
+}
+
+// Pad a set of bytes following PKCS5 algorithm
+func pkcs5Pad(buf []byte, blockSize int) ([]byte, error) {
+	len := len(buf)
+	pad := blockSize - (len % blockSize)
+	padText := bytes.Repeat([]byte{byte(pad)}, pad)
+	return append(buf, padText...), nil
+}