feat: added cipher text decrypt function (#355)

client/decrypt/decrypt.go

@@ -0,0 +1,98 @@
+package decrypt
+
+import (
+	"encoding/hex"
+	"fmt"
+	"github.com/btcsuite/btcd/btcec"
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/client/flags"
+	"github.com/cosmos/cosmos-sdk/crypto/keyring"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"github.com/tendermint/tendermint/libs/cli"
+	"io/ioutil"
+)
+
+const (
+	FlagCipherText     = "cipher-text"
+	FlagCipherTextPath = "path"
+)
+
+func Command(defaultNodeHome string) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "decrypt [name] (--cipher-text [ciphertext] | --path [ciphertext-file])",
+		Short: "Decrypt and output the ciphertext file encrypted with ECDSA PublicKey.",
+		Long: `This command can decrypt ciphertext encrypted with ECDSA PublicKey. 
+And your key should be stored in the localStore.
+(According to the following command (panacead keys add ...)`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx := client.GetClientContextFromCmd(cmd)
+
+			privKeyHex, err := keyring.NewUnsafe(clientCtx.Keyring).UnsafeExportPrivKeyHex(args[0])
+			if err != nil {
+				return err
+			}
+
+			privKey, err := hex.DecodeString(privKeyHex)
+			if err != nil {
+				return err
+			}
+
+			content, err := getContent(cmd.Flags())
+
+			if err != nil {
+				return fmt.Errorf("failed read cipherText. %w", err)
+			}
+
+			ecdsaPrivKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), privKey)
+			if err != nil {
+				return err
+			}
+			plainText, err := btcec.Decrypt(ecdsaPrivKey, content)
+			if err != nil {
+				return err
+			}
+
+			cmd.Println(string(plainText))
+
+			return nil
+		},
+	}
+
+	cmd.PersistentFlags().String(flags.FlagHome, defaultNodeHome, "The application home directory")
+	cmd.PersistentFlags().String(flags.FlagKeyringDir, "", "The client Keyring directory; if omitted, the default 'home' directory will be used")
+	cmd.PersistentFlags().String(flags.FlagKeyringBackend, flags.DefaultKeyringBackend, "Select keyring's backend (os|file|test)")
+	cmd.PersistentFlags().String(cli.OutputFlag, "text", "Output format (text|json)")
+	cmd.Flags().String(FlagCipherText, "", "Cipher text in the form of a byte array")
+	cmd.Flags().String(FlagCipherTextPath, "", "Path to the file where the cipher text in the form of a byte array is stored")
+
+	return cmd
+}
+
+func getContent(flag *pflag.FlagSet) ([]byte, error) {
+	cipherText, err := flag.GetString(FlagCipherText)
+	if err != nil {
+		return nil, err
+	}
+	cipherTextPath, err := flag.GetString(FlagCipherTextPath)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(cipherText) == 0 && len(cipherTextPath) == 0 {
+		return nil, fmt.Errorf("either --text or --path should be required")
+	} else if len(cipherText) != 0 && len(cipherTextPath) != 0 {
+		return nil, fmt.Errorf("only one of --text or --path should be specified")
+	}
+
+	if len(cipherText) != 0 {
+		return []byte(cipherText), nil
+	}
+
+	content, err := ioutil.ReadFile(cipherTextPath)
+	if err != nil {
+		return nil, err
+	}
+	return content, nil
+}

cmd/panacead/cmd/root.go

@@ -37,6 +37,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/crisis"
 	genutilcli "github.com/cosmos/cosmos-sdk/x/genutil/client/cli"
 	"github.com/medibloc/panacea-core/v2/app"
+	"github.com/medibloc/panacea-core/v2/client/decrypt"
 
 	wasmkeeper "github.com/CosmWasm/wasmd/x/wasm/keeper"
 )
@@ -106,6 +107,7 @@ func initRootCmd(rootCmd *cobra.Command, encodingConfig params.EncodingConfig) {
 		queryCommand(),
 		txCommand(),
 		keys.Commands(app.DefaultNodeHome),
+		decrypt.Command(app.DefaultNodeHome),
 	)
 }
 

go.mod

@@ -4,6 +4,7 @@ go 1.15
 
 require (
 	github.com/CosmWasm/wasmd v0.21.0
+	github.com/btcsuite/btcd v0.22.0-beta
 	github.com/btcsuite/btcutil v1.0.3-0.20201208143702-a53e38424cce
 	github.com/cosmos/cosmos-sdk v0.42.11
 	github.com/cosmos/go-bip39 v1.0.0