Major refactoring: Split up "cryptfs" into several internal packages

"git status" for reference:

deleted:    cryptfs/cryptfs.go
deleted:    cryptfs/names_core.go
modified:   integration_tests/cli_test.go
modified:   integration_tests/helpers.go
renamed:    cryptfs/config_file.go -> internal/configfile/config_file.go
renamed:    cryptfs/config_test.go -> internal/configfile/config_test.go
renamed:    cryptfs/config_test/.gitignore -> internal/configfile/config_test/.gitignore
renamed:    cryptfs/config_test/PlaintextNames.conf -> internal/configfile/config_test/PlaintextNames.conf
renamed:    cryptfs/config_test/StrangeFeature.conf -> internal/configfile/config_test/StrangeFeature.conf
renamed:    cryptfs/config_test/v1.conf -> internal/configfile/config_test/v1.conf
renamed:    cryptfs/config_test/v2.conf -> internal/configfile/config_test/v2.conf
renamed:    cryptfs/kdf.go -> internal/configfile/kdf.go
renamed:    cryptfs/kdf_test.go -> internal/configfile/kdf_test.go
renamed:    cryptfs/cryptfs_content.go -> internal/contentenc/content.go
new file:   internal/contentenc/content_api.go
renamed:    cryptfs/content_test.go -> internal/contentenc/content_test.go
renamed:    cryptfs/file_header.go -> internal/contentenc/file_header.go
renamed:    cryptfs/intrablock.go -> internal/contentenc/intrablock.go
renamed:    cryptfs/address_translation.go -> internal/contentenc/offsets.go
new file:   internal/cryptocore/crypto_api.go
renamed:    cryptfs/gcm_go1.4.go -> internal/cryptocore/gcm_go1.4.go
renamed:    cryptfs/gcm_go1.5.go -> internal/cryptocore/gcm_go1.5.go
renamed:    cryptfs/nonce.go -> internal/cryptocore/nonce.go
renamed:    cryptfs/openssl_aead.go -> internal/cryptocore/openssl_aead.go
renamed:    cryptfs/openssl_benchmark.bash -> internal/cryptocore/openssl_benchmark.bash
renamed:    cryptfs/openssl_test.go -> internal/cryptocore/openssl_test.go
new file:   internal/nametransform/name_api.go
new file:   internal/nametransform/names_core.go
renamed:    cryptfs/names_diriv.go -> internal/nametransform/names_diriv.go
renamed:    cryptfs/names_noiv.go -> internal/nametransform/names_noiv.go
renamed:    cryptfs/names_test.go -> internal/nametransform/names_test.go
new file:   internal/nametransform/pad16.go
renamed:    cryptfs/log.go -> internal/toggledlog/log.go
renamed:    cryptfs/log_go1.4.go -> internal/toggledlog/log_go1.4.go
renamed:    cryptfs/log_go1.5.go -> internal/toggledlog/log_go1.5.go
modified:   main.go
modified:   masterkey.go
modified:   pathfs_frontend/file.go
modified:   pathfs_frontend/file_holes.go
modified:   pathfs_frontend/fs.go
modified:   pathfs_frontend/fs_dir.go
modified:   pathfs_frontend/names.go
modified:   test.bash

1 files changed, 0 insertions, 134 deletions

diff --git a/cryptfs/names_core.go b/cryptfs/names_core.go
deleted file mode 100644
index 0f2e5b3..0000000
--- a/cryptfs/names_core.go
+++ /dev/null
@@ -1,134 +0,0 @@
-package cryptfs
-
-// Filename encryption / decryption functions
-
-import (
-	"crypto/aes"
-	"crypto/cipher"
-	"encoding/base64"
-	"errors"
-	"fmt"
-
-	"github.com/rfjakob/eme"
-)
-
-// DecryptName - decrypt base64-encoded encrypted filename "cipherName"
-// The used encryption is either CBC or EME, depending on the "EMENames" argument.
-//
-// This function is exported because it allows for a very efficient readdir
-// implementation (read IV once, decrypt all names using this function).
-func (be *CryptFS) DecryptName(cipherName string, iv []byte, EMENames bool) (string, error) {
-	return be.decryptName(cipherName, iv, EMENames)
-}
-
-// decryptName - decrypt base64-encoded encrypted filename "cipherName".
-// The used encryption is either CBC or EME, depending on the "EMENames" argument.
-func (be *CryptFS) decryptName(cipherName string, iv []byte, EMENames bool) (string, error) {
-
-	// Make sure relative symlinks still work after encryption
-	// by passing these through unchanged
-	if cipherName == "." || cipherName == ".." {
-		return cipherName, nil
-	}
-
-	bin, err := base64.URLEncoding.DecodeString(cipherName)
-	if err != nil {
-		return "", err
-	}
-
-	if len(bin)%aes.BlockSize != 0 {
-		return "", fmt.Errorf("Decoded length %d is not a multiple of the AES block size", len(bin))
-	}
-
-	if EMENames {
-		bin = eme.Transform(be.blockCipher, iv, bin, eme.DirectionDecrypt)
-	} else {
-		cbc := cipher.NewCBCDecrypter(be.blockCipher, iv)
-		cbc.CryptBlocks(bin, bin)
-	}
-
-	bin, err = be.unPad16(bin)
-	if err != nil {
-		return "", err
-	}
-
-	plain := string(bin)
-	return plain, err
-}
-
-// encryptName - encrypt "plainName", return base64-encoded "cipherName64"
-// The used encryption is either CBC or EME, depending on the "EMENames" argument.
-func (be *CryptFS) encryptName(plainName string, iv []byte, EMENames bool) (cipherName64 string) {
-
-	// Make sure relative symlinks still work after encryption
-	// by passing these trough unchanged
-	if plainName == "." || plainName == ".." {
-		return plainName
-	}
-
-	bin := []byte(plainName)
-	bin = be.pad16(bin)
-
-	if EMENames {
-		bin = eme.Transform(be.blockCipher, iv, bin, eme.DirectionEncrypt)
-	} else {
-		cbc := cipher.NewCBCEncrypter(be.blockCipher, iv)
-		cbc.CryptBlocks(bin, bin)
-	}
-
-	cipherName64 = base64.URLEncoding.EncodeToString(bin)
-	return cipherName64
-}
-
-// pad16 - pad filename to 16 byte blocks using standard PKCS#7 padding
-// https://tools.ietf.org/html/rfc5652#section-6.3
-func (be *CryptFS) pad16(orig []byte) (padded []byte) {
-	oldLen := len(orig)
-	if oldLen == 0 {
-		panic("Padding zero-length string makes no sense")
-	}
-	padLen := aes.BlockSize - oldLen%aes.BlockSize
-	if padLen == 0 {
-		padLen = aes.BlockSize
-	}
-	newLen := oldLen + padLen
-	padded = make([]byte, newLen)
-	copy(padded, orig)
-	padByte := byte(padLen)
-	for i := oldLen; i < newLen; i++ {
-		padded[i] = padByte
-	}
-	return padded
-}
-
-// unPad16 - remove padding
-func (be *CryptFS) unPad16(orig []byte) ([]byte, error) {
-	oldLen := len(orig)
-	if oldLen%aes.BlockSize != 0 {
-		return nil, errors.New("Unaligned size")
-	}
-	// The last byte is always a padding byte
-	padByte := orig[oldLen-1]
-	// The padding byte's value is the padding length
-	padLen := int(padByte)
-	// Padding must be at least 1 byte
-	if padLen <= 0 {
-		return nil, errors.New("Padding cannot be zero-length")
-	}
-	// Larger paddings make no sense
-	if padLen > aes.BlockSize {
-		return nil, errors.New("Padding cannot be larger than 16")
-	}
-	// All padding bytes must be identical
-	for i := oldLen - padLen; i < oldLen; i++ {
-		if orig[i] != padByte {
-			return nil, errors.New(fmt.Sprintf("Padding byte at i=%d is invalid", i))
-		}
-	}
-	newLen := oldLen - padLen
-	// Padding an empty string makes no sense
-	if newLen == 0 {
-		return nil, errors.New("Unpadded length is zero")
-	}
-	return orig[0:newLen], nil
-}