R4R: Improve crypto/keys and add keys mnemonic and keys new commands

Gopkg.toml

@@ -59,22 +59,51 @@
   name = "github.com/tendermint/tendermint"
   version = "=0.25.0"
 
+## deps without releases:
+
+[[constraint]]
+  name = "golang.org/x/crypto"
+  source = "https://github.com/tendermint/crypto"
+  revision = "3764759f34a542a3aef74d6b02e35be7ab893bba"
+
 [[constraint]]
-  name = "github.com/bartekn/go-bip39"
-  revision = "a05967ea095d81c8fe4833776774cfaff8e5036c"
+  name = "github.com/cosmos/go-bip39"
+  revision = "52158e4697b87de16ed390e1bdaf813e581008fa"
 
 [[constraint]]
   name = "github.com/zondax/ledger-goclient"
   version = "=v0.1.0"
 
+## transitive deps, with releases:
+
+[[override]]
+  name = "github.com/davecgh/go-spew"
+  version = "=v1.1.0"
+
 [[constraint]]
   name = "github.com/rakyll/statik"
   version = "=v0.1.4"
 
+[[constraint]]
+  name = "github.com/mitchellh/go-homedir"
+  version = "1.0.0"
+
+## transitive deps, without releases:
+#
+
+[[override]]
+  name = "github.com/syndtr/goleveldb"
+  revision = "c4c61651e9e37fa117f53c5a906d3b63090d8445"
+
+[[override]]
+  name = "golang.org/x/sys"
+  revision = "4e1fef5609515ec7a2cee7b5de30ba6d9b438cbf"
+
+[[override]]
+  name = "google.golang.org/genproto"
+  revision = "383e8b2c3b9e36c4076b235b32537292176bae20"
+
 [prune]
   go-tests = true
   unused-packages = true
 
-[[constraint]]
-  name = "github.com/mitchellh/go-homedir"
-  version = "1.0.0"

client/input.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/bgentry/speakeasy"
-	isatty "github.com/mattn/go-isatty"
+	"github.com/mattn/go-isatty"
 	"github.com/pkg/errors"
 )
 
@@ -44,13 +44,8 @@ func GetPassword(prompt string, buf *bufio.Reader) (pass string, err error) {
 
 // GetSeed will request a seed phrase from stdin and trims off
 // leading/trailing spaces
-func GetSeed(prompt string, buf *bufio.Reader) (seed string, err error) {
-	if inputIsTty() {
-		fmt.Println(prompt)
-	}
-	seed, err = readLineFromBuf(buf)
-	seed = strings.TrimSpace(seed)
-	return
+func GetSeed(prompt string, buf *bufio.Reader) (string, error) {
+	return GetString(prompt, buf)
 }
 
 // GetCheckPassword will prompt for a password twice to verify they
@@ -133,5 +128,6 @@ func readLineFromBuf(buf *bufio.Reader) (string, error) {
 
 // PrintPrefixed prints a string with > prefixed for use in prompts.
 func PrintPrefixed(msg string) {
-	fmt.Printf("> %s\n", msg)
+	msg = fmt.Sprintf("> %s\n", msg)
+	fmt.Fprint(os.Stderr, msg)
 }

client/keys/mnemonic.go

@@ -0,0 +1,78 @@
+package keys
+
+import (
+	"crypto/sha256"
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/spf13/cobra"
+
+	bip39 "github.com/bartekn/go-bip39"
+)
+
+const (
+	flagUserEntropy = "unsafe-entropy"
+
+	mnemonicEntropySize = 256
+)
+
+func mnemonicKeyCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "mnemonic",
+		Short: "Compute the bip39 mnemonic for some input entropy",
+		Long:  "Create a bip39 mnemonic, sometimes called a seed phrase, by reading from the system entropy. To pass your own entropy, use --unsafe-entropy",
+		RunE:  runMnemonicCmd,
+	}
+	cmd.Flags().Bool(flagUserEntropy, false, "Prompt the user to supply their own entropy, instead of relying on the system")
+	return cmd
+}
+
+func runMnemonicCmd(cmd *cobra.Command, args []string) error {
+	flags := cmd.Flags()
+
+	userEntropy, _ := flags.GetBool(flagUserEntropy)
+
+	var entropySeed []byte
+
+	if userEntropy {
+		// prompt the user to enter some entropy
+		buf := client.BufferStdin()
+		inputEntropy, err := client.GetString("> WARNING: Generate at least 256-bits of entropy and enter the results here:", buf)
+		if err != nil {
+			return err
+		}
+		if len(inputEntropy) < 43 {
+			return fmt.Errorf("256-bits is 43 characters in Base-64, and 100 in Base-6. You entered %v, and probably want more", len(inputEntropy))
+		}
+		conf, err := client.GetConfirmation(
+			fmt.Sprintf("> Input length: %d", len(inputEntropy)),
+			buf)
+		if err != nil {
+			return err
+		}
+		if !conf {
+			return nil
+		}
+
+		// hash input entropy to get entropy seed
+		hashedEntropy := sha256.Sum256([]byte(inputEntropy))
+		entropySeed = hashedEntropy[:]
+		printStep()
+	} else {
+		// read entropy seed straight from crypto.Rand
+		var err error
+		entropySeed, err = bip39.NewEntropy(mnemonicEntropySize)
+		if err != nil {
+			return err
+		}
+	}
+
+	mnemonic, err := bip39.NewMnemonic(entropySeed[:])
+	if err != nil {
+		return err
+	}
+
+	fmt.Println(mnemonic)
+
+	return nil
+}