Add multisign command

Ref: #3198

Author: Alessio Treglia

cmd/gaia/cmd/gaiacli/main.go

@@ -136,6 +136,7 @@ func txCmd(cdc *amino.Codec, mc []sdk.ModuleClients) *cobra.Command {
 		bankcmd.SendTxCmd(cdc),
 		client.LineBreak,
 		authcmd.GetSignCommand(cdc),
+		authcmd.GetMultiSignCommand(cdc),
 		bankcmd.GetBroadcastCommand(cdc),
 		client.LineBreak,
 	)

x/auth/client/cli/multisign.go

@@ -0,0 +1,131 @@
+package cli
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	amino "github.com/tendermint/go-amino"
+	"github.com/tendermint/tendermint/crypto/multisig"
+	"github.com/tendermint/tendermint/libs/cli"
+
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/client/context"
+	"github.com/cosmos/cosmos-sdk/client/keys"
+	crkeys "github.com/cosmos/cosmos-sdk/crypto/keys"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+)
+
+// GetSignCommand returns the sign command
+func GetMultiSignCommand(codec *amino.Codec) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "multisign <file> <name> <<signature>...>",
+		Short: "Generate multisig signatures for transactions generated offline",
+		Long: `Sign transactions created with the --generate-only flag that require multisig signatures.
+
+Read signature(s) from <signature> file(s), generate a multisig signature compliant to the
+offline multisig key <name>, and attach it to the transaction read from <file>.
+
+The --offline flag makes sure that the client will not reach out to an external node.
+Thus account number or sequence number lookups will not be performed and it is
+recommended to set such parameters manually.`,
+		RunE: makeMultiSignCmd(codec),
+		Args: cobra.MinimumNArgs(3),
+	}
+	cmd.Flags().String(client.FlagName, "", "Name of multisig (offline) public key")
+	cmd.Flags().Bool(flagSigOnly, false, "Print only the generated signature, then exit.")
+	cmd.Flags().Bool(flagOffline, false, "Offline mode. Do not query a full node.")
+	cmd.Flags().String(flagOutfile, "",
+		"The document will be written to the given file instead of STDOUT")
+
+	// Add the flags here and return the command
+	return client.PostCommands(cmd)[0]
+}
+
+func makeMultiSignCmd(cdc *amino.Codec) func(cmd *cobra.Command, args []string) error {
+	return func(cmd *cobra.Command, args []string) (err error) {
+		stdTx, err := readAndUnmarshalStdTx(cdc, args[0])
+		if err != nil {
+			return
+		}
+
+		keybase, err := keys.GetKeyBaseFromDir(viper.GetString(cli.HomeFlag))
+		if err != nil {
+			return
+		}
+
+		multisigInfo, err := keybase.Get(args[1])
+		if err != nil {
+			return
+		}
+		if multisigInfo.GetType() != crkeys.TypeOffline {
+			return fmt.Errorf("%q must be of type offline: %s",
+				args[1], multisigInfo.GetType())
+		}
+
+		multisigPub := multisigInfo.GetPubKey().(*multisig.PubKeyMultisigThreshold)
+		multisigSig := multisig.NewMultisig(len(args) - 2)
+		for i := 2; i < len(args); i++ {
+			stdSig, err := readAndUnmarshalStdSignature(cdc, args[i])
+			if err != nil {
+				return err
+			}
+			multisigSig.AddSignatureFromPubKey(stdSig.Signature, stdSig.PubKey, multisigPub.PubKeys)
+		}
+
+		cliCtx := context.NewCLIContext().WithCodec(cdc).WithAccountDecoder(cdc)
+		newStdSig := auth.StdSignature{Signature: multisigSig.Marshal(), PubKey: multisigPub}
+		newTx := auth.NewStdTx(stdTx.GetMsgs(), stdTx.Fee, []auth.StdSignature{newStdSig}, stdTx.GetMemo())
+
+		var json []byte
+		switch viper.GetBool(flagSigOnly) {
+		case true:
+			switch cliCtx.Indent {
+			case true:
+				json, err = cdc.MarshalJSONIndent(newTx.Signatures[0], "", "  ")
+			default:
+				json, err = cdc.MarshalJSON(newTx.Signatures[0])
+			}
+		default:
+			switch cliCtx.Indent {
+			case true:
+				json, err = cdc.MarshalJSONIndent(newTx, "", "  ")
+			default:
+				json, err = cdc.MarshalJSON(newTx)
+			}
+		}
+		if err != nil {
+			return err
+		}
+
+		if viper.GetString(flagOutfile) == "" {
+			fmt.Printf("%s\n", json)
+			return
+		}
+
+		fp, err := os.OpenFile(
+			viper.GetString(flagOutfile), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644,
+		)
+		if err != nil {
+			return err
+		}
+		defer fp.Close()
+
+		fmt.Fprintf(fp, "%s\n", json)
+
+		return
+	}
+}
+
+func readAndUnmarshalStdSignature(cdc *amino.Codec, filename string) (stdSig auth.StdSignature, err error) {
+	var bytes []byte
+	if bytes, err = ioutil.ReadFile(filename); err != nil {
+		return
+	}
+	if err = cdc.UnmarshalJSON(bytes, &stdSig); err != nil {
+		return
+	}
+	return
+}