From 543fdbb9bcd4fa65e4c9b5192426f6f0a99e2d76 Mon Sep 17 00:00:00 2001
From: Eugene Kim <ek@harmony.one>
Date: Wed, 19 Jun 2019 14:32:56 -0700
Subject: [PATCH] Try to decode BLS key as hex and binary forms

If both forms fail, return the error from the hexadecimal attempt,
because hexadecimal is the canonical form and binary is only a fallback.
---
 internal/blsgen/lib.go | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/internal/blsgen/lib.go b/internal/blsgen/lib.go
index d145d809d..c1a946a2a 100644
--- a/internal/blsgen/lib.go
+++ b/internal/blsgen/lib.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	ffi_bls "github.com/harmony-one/bls/ffi/go/bls"
+
 	"github.com/harmony-one/harmony/crypto/bls"
 )
 
@@ -83,8 +84,7 @@ func LoadBlsKeyWithPassPhrase(fileName, passphrase string) (*ffi_bls.SecretKey,
 	for len(passphrase) > 0 && passphrase[len(passphrase)-1] == '\n' {
 		passphrase = passphrase[:len(passphrase)-1]
 	}
-	encryptedPrivateKeyStr := string(encryptedPrivateKeyBytes)
-	decryptedBytes, err := decrypt(encryptedPrivateKeyStr, passphrase)
+	decryptedBytes, err := decrypt(encryptedPrivateKeyBytes, passphrase)
 	if err != nil {
 		return nil, err
 	}
@@ -114,7 +114,24 @@ func encrypt(data []byte, passphrase string) (string, error) {
 	return hex.EncodeToString(ciphertext), nil
 }
 
-func decrypt(encryptedStr string, passphrase string) ([]byte, error) {
+func decrypt(encrypted []byte, passphrase string) (decrypted []byte, err error) {
+	unhexed := make([]byte, hex.DecodedLen(len(encrypted)))
+	if _, err = hex.Decode(unhexed, encrypted); err == nil {
+		if decrypted, err = decryptRaw(unhexed, passphrase); err == nil {
+			return decrypted, nil
+		}
+	}
+	// At this point err != nil, either from hex decode or from decryptRaw.
+	decrypted, binErr := decryptRaw(encrypted, passphrase)
+	if binErr != nil {
+		// Disregard binary decryption error and return the original error,
+		// because our canonical form is hex and not binary.
+		return nil, err
+	}
+	return decrypted, nil
+}
+
+func decryptRaw(data []byte, passphrase string) ([]byte, error) {
 	var err error
 	key := []byte(createHash(passphrase))
 	block, err := aes.NewCipher(key)
@@ -125,11 +142,6 @@ func decrypt(encryptedStr string, passphrase string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	data, err := hex.DecodeString(encryptedStr)
-	if err != nil {
-		return nil, err
-	}
-
 	nonceSize := gcm.NonceSize()
 	nonce, ciphertext := data[:nonceSize], data[nonceSize:]
 	plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)