diff options
author | Jakob Unterwurzacher | 2016-02-06 19:20:54 +0100 |
---|---|---|
committer | Jakob Unterwurzacher | 2016-02-06 19:22:35 +0100 |
commit | 2b8cbd944149afe51fadddbd67ee4499d1d86250 (patch) | |
tree | 76361984cc4394bbb9b19ae987aeaff71fb6073b /internal/nametransform/names_core.go | |
parent | adcfbd79a8b8bb85cbee25996ab622a05de0dbc1 (diff) |
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
Diffstat (limited to 'internal/nametransform/names_core.go')
-rw-r--r-- | internal/nametransform/names_core.go | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/internal/nametransform/names_core.go b/internal/nametransform/names_core.go new file mode 100644 index 0000000..452ab45 --- /dev/null +++ b/internal/nametransform/names_core.go @@ -0,0 +1,63 @@ +package nametransform + +// Filename encryption / decryption functions + +import ( + "crypto/aes" + "crypto/cipher" + "encoding/base64" + "fmt" + + "github.com/rfjakob/eme" +) + +// DecryptName - decrypt base64-encoded encrypted filename "cipherName" +// The used encryption is either CBC or EME, depending on "useEME". +// +// This function is exported because it allows for a very efficient readdir +// implementation (read IV once, decrypt all names using this function). +func (n *NameTransform) DecryptName(cipherName string, iv []byte) (string, error) { + + 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 n.useEME { + bin = eme.Transform(n.cryptoCore.BlockCipher, iv, bin, eme.DirectionDecrypt) + } else { + cbc := cipher.NewCBCDecrypter(n.cryptoCore.BlockCipher, iv) + cbc.CryptBlocks(bin, bin) + } + + bin, err = 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 "useEME". +func (n *NameTransform) encryptName(plainName string, iv []byte) (cipherName64 string) { + + bin := []byte(plainName) + bin = pad16(bin) + + if n.useEME { + bin = eme.Transform(n.cryptoCore.BlockCipher, iv, bin, eme.DirectionEncrypt) + } else { + cbc := cipher.NewCBCEncrypter(n.cryptoCore.BlockCipher, iv) + cbc.CryptBlocks(bin, bin) + } + + cipherName64 = base64.URLEncoding.EncodeToString(bin) + return cipherName64 +} + |