From d235e2c6a5788ec4a6cff15a16f56b38a3876a0d Mon Sep 17 00:00:00 2001 From: Determinant Date: Sun, 28 Jun 2020 14:47:41 -0400 Subject: ... --- accounts/keystore/passphrase.go | 356 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 356 insertions(+) create mode 100644 accounts/keystore/passphrase.go (limited to 'accounts/keystore/passphrase.go') diff --git a/accounts/keystore/passphrase.go b/accounts/keystore/passphrase.go new file mode 100644 index 0000000..fa5a09d --- /dev/null +++ b/accounts/keystore/passphrase.go @@ -0,0 +1,356 @@ +// Copyright 2014 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +/* + +This key store behaves as KeyStorePlain with the difference that +the private key is encrypted and on disk uses another JSON encoding. + +The crypto is documented at https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition + +*/ + +package keystore + +import ( + "bytes" + "crypto/aes" + "crypto/rand" + "crypto/sha256" + "encoding/hex" + "encoding/json" + "fmt" + "io" + "io/ioutil" + "os" + "path/filepath" + + "github.com/ava-labs/coreth/accounts" + "github.com/ava-labs/go-ethereum/common" + "github.com/ava-labs/go-ethereum/common/math" + "github.com/ava-labs/go-ethereum/crypto" + "github.com/pborman/uuid" + "golang.org/x/crypto/pbkdf2" + "golang.org/x/crypto/scrypt" +) + +const ( + keyHeaderKDF = "scrypt" + + // StandardScryptN is the N parameter of Scrypt encryption algorithm, using 256MB + // memory and taking approximately 1s CPU time on a modern processor. + StandardScryptN = 1 << 18 + + // StandardScryptP is the P parameter of Scrypt encryption algorithm, using 256MB + // memory and taking approximately 1s CPU time on a modern processor. + StandardScryptP = 1 + + // LightScryptN is the N parameter of Scrypt encryption algorithm, using 4MB + // memory and taking approximately 100ms CPU time on a modern processor. + LightScryptN = 1 << 12 + + // LightScryptP is the P parameter of Scrypt encryption algorithm, using 4MB + // memory and taking approximately 100ms CPU time on a modern processor. + LightScryptP = 6 + + scryptR = 8 + scryptDKLen = 32 +) + +type keyStorePassphrase struct { + keysDirPath string + scryptN int + scryptP int + // skipKeyFileVerification disables the security-feature which does + // reads and decrypts any newly created keyfiles. This should be 'false' in all + // cases except tests -- setting this to 'true' is not recommended. + skipKeyFileVerification bool +} + +func (ks keyStorePassphrase) GetKey(addr common.Address, filename, auth string) (*Key, error) { + // Load the key from the keystore and decrypt its contents + keyjson, err := ioutil.ReadFile(filename) + if err != nil { + return nil, err + } + key, err := DecryptKey(keyjson, auth) + if err != nil { + return nil, err + } + // Make sure we're really operating on the requested key (no swap attacks) + if key.Address != addr { + return nil, fmt.Errorf("key content mismatch: have account %x, want %x", key.Address, addr) + } + return key, nil +} + +// StoreKey generates a key, encrypts with 'auth' and stores in the given directory +func StoreKey(dir, auth string, scryptN, scryptP int) (accounts.Account, error) { + _, a, err := storeNewKey(&keyStorePassphrase{dir, scryptN, scryptP, false}, rand.Reader, auth) + return a, err +} + +func (ks keyStorePassphrase) StoreKey(filename string, key *Key, auth string) error { + keyjson, err := EncryptKey(key, auth, ks.scryptN, ks.scryptP) + if err != nil { + return err + } + // Write into temporary file + tmpName, err := writeTemporaryKeyFile(filename, keyjson) + if err != nil { + return err + } + if !ks.skipKeyFileVerification { + // Verify that we can decrypt the file with the given password. + _, err = ks.GetKey(key.Address, tmpName, auth) + if err != nil { + msg := "An error was encountered when saving and verifying the keystore file. \n" + + "This indicates that the keystore is corrupted. \n" + + "The corrupted file is stored at \n%v\n" + + "Please file a ticket at:\n\n" + + "https://github.com/ethereum/go-ethereum/issues." + + "The error was : %s" + return fmt.Errorf(msg, tmpName, err) + } + } + return os.Rename(tmpName, filename) +} + +func (ks keyStorePassphrase) JoinPath(filename string) string { + if filepath.IsAbs(filename) { + return filename + } + return filepath.Join(ks.keysDirPath, filename) +} + +// Encryptdata encrypts the data given as 'data' with the password 'auth'. +func EncryptDataV3(data, auth []byte, scryptN, scryptP int) (CryptoJSON, error) { + + salt := make([]byte, 32) + if _, err := io.ReadFull(rand.Reader, salt); err != nil { + panic("reading from crypto/rand failed: " + err.Error()) + } + derivedKey, err := scrypt.Key(auth, salt, scryptN, scryptR, scryptP, scryptDKLen) + if err != nil { + return CryptoJSON{}, err + } + encryptKey := derivedKey[:16] + + iv := make([]byte, aes.BlockSize) // 16 + if _, err := io.ReadFull(rand.Reader, iv); err != nil { + panic("reading from crypto/rand failed: " + err.Error()) + } + cipherText, err := aesCTRXOR(encryptKey, data, iv) + if err != nil { + return CryptoJSON{}, err + } + mac := crypto.Keccak256(derivedKey[16:32], cipherText) + + scryptParamsJSON := make(map[string]interface{}, 5) + scryptParamsJSON["n"] = scryptN + scryptParamsJSON["r"] = scryptR + scryptParamsJSON["p"] = scryptP + scryptParamsJSON["dklen"] = scryptDKLen + scryptParamsJSON["salt"] = hex.EncodeToString(salt) + cipherParamsJSON := cipherparamsJSON{ + IV: hex.EncodeToString(iv), + } + + cryptoStruct := CryptoJSON{ + Cipher: "aes-128-ctr", + CipherText: hex.EncodeToString(cipherText), + CipherParams: cipherParamsJSON, + KDF: keyHeaderKDF, + KDFParams: scryptParamsJSON, + MAC: hex.EncodeToString(mac), + } + return cryptoStruct, nil +} + +// EncryptKey encrypts a key using the specified scrypt parameters into a json +// blob that can be decrypted later on. +func EncryptKey(key *Key, auth string, scryptN, scryptP int) ([]byte, error) { + keyBytes := math.PaddedBigBytes(key.PrivateKey.D, 32) + cryptoStruct, err := EncryptDataV3(keyBytes, []byte(auth), scryptN, scryptP) + if err != nil { + return nil, err + } + encryptedKeyJSONV3 := encryptedKeyJSONV3{ + hex.EncodeToString(key.Address[:]), + cryptoStruct, + key.Id.String(), + version, + } + return json.Marshal(encryptedKeyJSONV3) +} + +// DecryptKey decrypts a key from a json blob, returning the private key itself. +func DecryptKey(keyjson []byte, auth string) (*Key, error) { + // Parse the json into a simple map to fetch the key version + m := make(map[string]interface{}) + if err := json.Unmarshal(keyjson, &m); err != nil { + return nil, err + } + // Depending on the version try to parse one way or another + var ( + keyBytes, keyId []byte + err error + ) + if version, ok := m["version"].(string); ok && version == "1" { + k := new(encryptedKeyJSONV1) + if err := json.Unmarshal(keyjson, k); err != nil { + return nil, err + } + keyBytes, keyId, err = decryptKeyV1(k, auth) + } else { + k := new(encryptedKeyJSONV3) + if err := json.Unmarshal(keyjson, k); err != nil { + return nil, err + } + keyBytes, keyId, err = decryptKeyV3(k, auth) + } + // Handle any decryption errors and return the key + if err != nil { + return nil, err + } + key := crypto.ToECDSAUnsafe(keyBytes) + + return &Key{ + Id: uuid.UUID(keyId), + Address: crypto.PubkeyToAddress(key.PublicKey), + PrivateKey: key, + }, nil +} + +func DecryptDataV3(cryptoJson CryptoJSON, auth string) ([]byte, error) { + if cryptoJson.Cipher != "aes-128-ctr" { + return nil, fmt.Errorf("Cipher not supported: %v", cryptoJson.Cipher) + } + mac, err := hex.DecodeString(cryptoJson.MAC) + if err != nil { + return nil, err + } + + iv, err := hex.DecodeString(cryptoJson.CipherParams.IV) + if err != nil { + return nil, err + } + + cipherText, err := hex.DecodeString(cryptoJson.CipherText) + if err != nil { + return nil, err + } + + derivedKey, err := getKDFKey(cryptoJson, auth) + if err != nil { + return nil, err + } + + calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText) + if !bytes.Equal(calculatedMAC, mac) { + return nil, ErrDecrypt + } + + plainText, err := aesCTRXOR(derivedKey[:16], cipherText, iv) + if err != nil { + return nil, err + } + return plainText, err +} + +func decryptKeyV3(keyProtected *encryptedKeyJSONV3, auth string) (keyBytes []byte, keyId []byte, err error) { + if keyProtected.Version != version { + return nil, nil, fmt.Errorf("Version not supported: %v", keyProtected.Version) + } + keyId = uuid.Parse(keyProtected.Id) + plainText, err := DecryptDataV3(keyProtected.Crypto, auth) + if err != nil { + return nil, nil, err + } + return plainText, keyId, err +} + +func decryptKeyV1(keyProtected *encryptedKeyJSONV1, auth string) (keyBytes []byte, keyId []byte, err error) { + keyId = uuid.Parse(keyProtected.Id) + mac, err := hex.DecodeString(keyProtected.Crypto.MAC) + if err != nil { + return nil, nil, err + } + + iv, err := hex.DecodeString(keyProtected.Crypto.CipherParams.IV) + if err != nil { + return nil, nil, err + } + + cipherText, err := hex.DecodeString(keyProtected.Crypto.CipherText) + if err != nil { + return nil, nil, err + } + + derivedKey, err := getKDFKey(keyProtected.Crypto, auth) + if err != nil { + return nil, nil, err + } + + calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText) + if !bytes.Equal(calculatedMAC, mac) { + return nil, nil, ErrDecrypt + } + + plainText, err := aesCBCDecrypt(crypto.Keccak256(derivedKey[:16])[:16], cipherText, iv) + if err != nil { + return nil, nil, err + } + return plainText, keyId, err +} + +func getKDFKey(cryptoJSON CryptoJSON, auth string) ([]byte, error) { + authArray := []byte(auth) + salt, err := hex.DecodeString(cryptoJSON.KDFParams["salt"].(string)) + if err != nil { + return nil, err + } + dkLen := ensureInt(cryptoJSON.KDFParams["dklen"]) + + if cryptoJSON.KDF == keyHeaderKDF { + n := ensureInt(cryptoJSON.KDFParams["n"]) + r := ensureInt(cryptoJSON.KDFParams["r"]) + p := ensureInt(cryptoJSON.KDFParams["p"]) + return scrypt.Key(authArray, salt, n, r, p, dkLen) + + } else if cryptoJSON.KDF == "pbkdf2" { + c := ensureInt(cryptoJSON.KDFParams["c"]) + prf := cryptoJSON.KDFParams["prf"].(string) + if prf != "hmac-sha256" { + return nil, fmt.Errorf("Unsupported PBKDF2 PRF: %s", prf) + } + key := pbkdf2.Key(authArray, salt, c, dkLen, sha256.New) + return key, nil + } + + return nil, fmt.Errorf("Unsupported KDF: %s", cryptoJSON.KDF) +} + +// TODO: can we do without this when unmarshalling dynamic JSON? +// why do integers in KDF params end up as float64 and not int after +// unmarshal? +func ensureInt(x interface{}) int { + res, ok := x.(int) + if !ok { + res = int(x.(float64)) + } + return res +} -- cgit v1.2.3-70-g09d2