Merge pull request #6 from algorand/maxj/add_mnemonic_type_support

Add mnemonic support for private keys/mdk

mnemonic/helpers.go

@@ -0,0 +1,44 @@
+package mnemonic
+
+import (
+	"golang.org/x/crypto/ed25519"
+
+	"github.com/algorand/go-algorand-sdk/types"
+)
+
+// FromPrivateKey is a helper that converts an ed25519 private key to a
+// human-readable mnemonic
+func FromPrivateKey(sk ed25519.PrivateKey) (string, error) {
+	seed := sk.Seed()
+	return FromKey(seed)
+}
+
+// ToPrivateKey is a helper that converts a mnemonic directly to an ed25519
+// private key
+func ToPrivateKey(mnemonic string) (sk ed25519.PrivateKey, err error) {
+	seedBytes, err := ToKey(mnemonic)
+	if err != nil {
+		return
+	}
+	return ed25519.NewKeyFromSeed(seedBytes), nil
+}
+
+// FromMasterDerivationKey is a helper that converts an MDK to a human-readable
+// mnemonic
+func FromMasterDerivationKey(mdk types.MasterDerivationKey) (string, error) {
+	return FromKey(mdk[:])
+}
+
+// ToMasterDerivationKey is a helper that converts a mnemonic directly to a
+// master derivation key
+func ToMasterDerivationKey(mnemonic string) (mdk types.MasterDerivationKey, err error) {
+	mdkBytes, err := ToKey(mnemonic)
+	if err != nil {
+		return
+	}
+	if len(mdkBytes) != len(mdk) {
+		panic("recovered mdk is wrong length")
+	}
+	copy(mdk[:], mdkBytes)
+	return
+}

mnemonic/mnemonic_test.go

@@ -6,6 +6,9 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+
+	"github.com/algorand/go-algorand-sdk/crypto"
+	"github.com/algorand/go-algorand-sdk/types"
 )
 
 func TestGenerateAndRecovery(t *testing.T) {
@@ -21,6 +24,31 @@ func TestGenerateAndRecovery(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, recovered, key)
 	}
+
+	var mdk types.MasterDerivationKey
+	for i := 0; i < 1000; i++ {
+		// Generate a mdk
+		_, err := rand.Read(key)
+		require.NoError(t, err)
+		copy(mdk[:], key)
+		// Go from mdk -> mnemonic
+		m, err := FromMasterDerivationKey(mdk)
+		// Go from mnemonic -> mdk
+		recovered, err := ToMasterDerivationKey(m)
+		require.NoError(t, err)
+		require.Equal(t, recovered, mdk)
+	}
+
+	for i := 0; i < 1000; i++ {
+		// Generate a private key
+		acct := crypto.GenerateAccount()
+		// Go from sk -> mnemonic
+		m, err := FromPrivateKey(acct.PrivateKey)
+		// Go from mnemonic -> sk
+		recovered, err := ToPrivateKey(m)
+		require.NoError(t, err)
+		require.Equal(t, recovered, acct.PrivateKey)
+	}
 }
 
 func TestZeroVector(t *testing.T) {