Support 12- and 18-word mnemonics with passphrases.

Allow single-world (no whitespace) passphrases for 12- and 18-word
mnemonics.

Fixes #87

CHANGELOG.md

@@ -2,6 +2,7 @@ dev:
   - initial support for deneb
   - add "--generate-keystore" option for "account derive"
   - update "validator exit" command to be able to generate multiple exits
+  - support for 12-word and 18-word mnemonics with single-word (no whitespace) passphrases
 
 1.30.0:
   - add "chain spec" command

util/mnemonic.go

@@ -40,13 +40,23 @@ var mnemonicWordLists = [][]string{
 
 // SeedFromMnemonic creates a seed from a mnemonic.
 func SeedFromMnemonic(mnemonic string) ([]byte, error) {
-	// If there are more than 24 words we treat the additional characters as the passphrase.
+	// Handle situations where there may be a passphrase with the mnemonic.
 	mnemonicParts := strings.Split(mnemonic, " ")
 	mnemonicPassphrase := ""
-	if len(mnemonicParts) > 24 {
+	switch {
+	case len(mnemonicParts) == 13:
+		// Assume that passphrase is a single word here.
+		mnemonic = strings.Join(mnemonicParts[:12], " ")
+		mnemonicPassphrase = mnemonicParts[12]
+	case len(mnemonicParts) == 19:
+		// Assume that passphrase is a single word here.
+		mnemonic = strings.Join(mnemonicParts[:18], " ")
+		mnemonicPassphrase = mnemonicParts[18]
+	case len(mnemonicParts) > 24:
 		mnemonic = strings.Join(mnemonicParts[:24], " ")
 		mnemonicPassphrase = strings.Join(mnemonicParts[24:], " ")
 	}
+
 	// Normalise the input.
 	mnemonic = string(norm.NFKD.Bytes([]byte(mnemonic)))
 	mnemonicPassphrase = string(norm.NFKD.Bytes([]byte(mnemonicPassphrase)))

util/mnemonic_test.go

@@ -42,10 +42,35 @@ func TestSeedFromMnemonic(t *testing.T) {
 			err:  "mnemonic is invalid",
 		},
 		{
-			name:     "Default",
+			name:     "Twelve",
+			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about",
+			seed:     bytesStr("0x5eb00bbddcf069084889a8ab9155568165f5c453ccb85e70811aaed6f6da5fc19a5ac40b389cd370d086206dec8aa6c43daea6690f20ad3d8d48b2d2ce9e38e4"),
+		},
+		{
+			name:     "TwelvePlusPassphrase",
+			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about passphrase",
+			seed:     bytesStr("0x4865438d10636e1453b2d3c06444c669b80fb1ae77111f1f91b64278ed4d493465276d2e00f93be2a8e82c2f72555370a4bf31bcf1f9addaf0a31499a3baeeae"),
+		},
+		{
+			name:     "Eighteen",
+			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon agent",
+			seed:     bytesStr("0x4975bb3d1faf5308c86a30893ee903a976296609db223fd717e227da5a813a34dc1428b71c84a787fc51f3b9f9dc28e9459f48c08bd9578e9d1b170f2d7ea506"),
+		},
+		{
+			name:     "EighteenPlusPassphrase",
+			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon agent passphrase",
+			seed:     bytesStr("0xbea1dd48440f3a8a7c02d0f7977fe03ba1dd409dda1ce971e80adc38f750c51d0959bd15c48cca2649cbcba8160d8a6c4026f2ee22dd387aa9b005041a5b8ea2"),
+		},
+		{
+			name:     "TwentyFour",
 			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon art",
 			seed:     bytesStr("0x408b285c123836004f4b8842c89324c1f01382450c0d439af345ba7fc49acf705489c6fc77dbd4e3dc1dd8cc6bc9f043db8ada1e243c4a0eafb290d399480840"),
 		},
+		{
+			name:     "TwentyFourPlusPassphrase",
+			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon art passphrase",
+			seed:     bytesStr("0x3b9096d658962052e9e778a18e7fddb8f530cbf783f38b26cf3e89fff6bf385728028ea0e906d47c24f88b666d61a59bdb88a7fc11b9e302ae75482c9562c282"),
+		},
 		{
 			name:     "English",
 			mnemonic: "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon art",