Improve encoding, closes echovl#37

* expose bech32 module for easy marshalling
* added convinient method to build stake credential from key hash

Signed-off-by: Marco Bardelli <[email protected]>

bech32/bech32.go

@@ -0,0 +1,122 @@
+package bech32
+
+import (
+	"fmt"
+
+	"github.com/echovl/cardano-go/bech32/prefixes"
+	"github.com/echovl/cardano-go/internal/bech32"
+)
+
+type Bech32Prefix = prefixes.Bech32Prefix
+
+var (
+	EncodeWithPrefix = bech32.Encode
+	Decode           = bech32.Decode
+	DecodeNoLimit    = bech32.DecodeNoLimit
+
+	EncodeFromBase256WithPrefix = bech32.EncodeFromBase256
+	DecodeToBase256             = bech32.DecodeToBase256
+)
+
+type (
+	Bech32Codec interface {
+		Prefix() string
+		Bytes() []byte
+		SetBytes([]byte)
+		Len() int
+	}
+	Bech32Encoder interface {
+		Prefix() string
+		Bytes() []byte
+	}
+)
+
+func Encode(args ...any) (string, error) {
+	var hrp string
+	var data []byte
+	switch len(args) {
+	case 1:
+		// the argument have to be a Bech32Codec
+		if c, ok := args[0].(Bech32Encoder); !ok {
+			return "", fmt.Errorf("Wrong parameter: %T is not a Bech32Encoder", c)
+		}
+		hrp = args[0].(Bech32Encoder).Prefix()
+		data = args[0].(Bech32Encoder).Bytes()
+	case 2:
+		// the argument haave to be a Bech32Codec or a string, and the second have to be a []byte
+		a1 := args[0]
+		a2 := args[1]
+
+		switch a1.(type) {
+		case Bech32Encoder:
+			hrp = a1.(Bech32Codec).Prefix()
+		case string:
+			hrp = a1.(string)
+		default:
+			return "", fmt.Errorf("Wrong 1st parameter: %T is not a string or Bech32Codec", a1)
+		}
+
+		if _, ok := a2.([]byte); !ok {
+			return "", fmt.Errorf("Wrong 2nd parameter: %T is not a []byte", a2)
+		}
+		data = a2.([]byte)
+	}
+	return bech32.Encode(hrp, data)
+}
+
+func EncodeFromBase256(args ...any) (string, error) {
+	var hrp string
+	var data []byte
+	switch len(args) {
+	case 1:
+		// the argument have to be a Bech32Codec
+		if c, ok := args[0].(Bech32Encoder); !ok {
+			return "", fmt.Errorf("Wrong parameter: %T is not a Bech32Encoder", c)
+		}
+		hrp = args[0].(Bech32Encoder).Prefix()
+		if converted, err := bech32.ConvertBits(args[0].(Bech32Encoder).Bytes(), 8, 5, true); err != nil {
+			return "", err
+		} else {
+			data = converted
+		}
+	case 2:
+		// the argument haave to be a Bech32Codec or a string, and the second have to be a []byte
+		a1 := args[0]
+		a2 := args[1]
+
+		switch a1.(type) {
+		case Bech32Encoder:
+			hrp = a1.(Bech32Encoder).Prefix()
+		case string:
+			hrp = a1.(string)
+		default:
+			return "", fmt.Errorf("Wrong 1st parameter: %T is not a string or Bech32Codec", a1)
+		}
+
+		if _, ok := a2.([]byte); !ok {
+			return "", fmt.Errorf("Wrong 2nd parameter: %T is not a []byte", a2)
+		}
+		if converted, err := bech32.ConvertBits(a2.([]byte), 8, 5, true); err != nil {
+		} else {
+			data = converted
+		}
+	}
+	return bech32.Encode(hrp, data)
+}
+
+func DecodeInto(be32 string, codec Bech32Codec) error {
+	expectedLen := codec.Len()
+	expectedPrefix := codec.Prefix()
+	hrp, data, err := bech32.DecodeToBase256(be32)
+	if err != nil {
+		return err
+	}
+	if hrp != expectedPrefix {
+		return fmt.Errorf("Wrong prefix: want %s got %s", expectedPrefix, hrp)
+	}
+	codec.SetBytes(data)
+	if len(codec.Bytes()) != expectedLen || string(codec.Bytes()) != string(data) {
+		return fmt.Errorf("Set bytes failed")
+	}
+	return nil
+}

bech32/prefixes/cip5.go

@@ -0,0 +1,91 @@
+package prefixes
+
+// As specified in [CIP-5](https://github.com/cardano-foundation/CIPs/tree/master/CIP5)
+//
+// copied from cardano-addresses core/lib/Cardano/Codec/Bech32/Prefixes.hs
+
+type Bech32Prefix = string
+
+const (
+	// -- * Addresses
+
+	Addr      Bech32Prefix = "addr"
+	AddrTest  Bech32Prefix = "addr_test"
+	Script    Bech32Prefix = "script"
+	Stake     Bech32Prefix = "stake"
+	StakeTest Bech32Prefix = "stake_test"
+
+	// -- * Hashes
+
+	AddrPublicKeyHash        Bech32Prefix = "addr_vkh"
+	StakePublicKeyHash       Bech32Prefix = "stake_vkh"
+	AddrSharedPublicKeyHash  Bech32Prefix = "addr_shared_vkh"
+	StakeSharedPublicKeyHash Bech32Prefix = "stake_shared_vkh"
+
+	// -- * Keys for 1852H
+	AddrPublicKey          Bech32Prefix = "addr_vk"
+	AddrPrivateKey         Bech32Prefix = "addr_sk"
+	AddrXPub               Bech32Prefix = "addr_xvk"
+	AddrXPrv               Bech32Prefix = "addr_xsk"
+	AddrExtendedPublicKey               = AddrXPub
+	AddrExtendedPrivateKey              = AddrXPrv
+
+	AcctPublicKey          Bech32Prefix = "acct_vk"
+	AcctPrivateKey         Bech32Prefix = "acct_sk"
+	AcctXPub               Bech32Prefix = "acct_xvk"
+	AcctXPrv               Bech32Prefix = "acct_xsk"
+	AcctExtendedPublicKey               = AcctXPub
+	AcctExtendedPrivateKey              = AcctXPrv
+
+	RootPublicKey          Bech32Prefix = "root_vk"
+	RootPrivateKey         Bech32Prefix = "root_sk"
+	RootXPub               Bech32Prefix = "root_xvk"
+	RootXPrv               Bech32Prefix = "root_xsk"
+	RootExtendedPublicKey               = RootXPub
+	RootExtendedPrivateKey              = RootXPrv
+
+	StakePublicKey          Bech32Prefix = "stake_vk"
+	StakePrivateKey         Bech32Prefix = "stake_sk"
+	StakeXPub               Bech32Prefix = "stake_xvk"
+	StakeXPrv               Bech32Prefix = "stake_xsk"
+	StakeExtendedPublicKey               = StakeXPub
+	StakeExtendedPrivateKey              = StakeXPrv
+
+	// -- * Keys for 1854H
+
+	AddrSharedPublicKey          Bech32Prefix = "addr_shared_vk"
+	AddrSharedPrivateKey         Bech32Prefix = "addr_shared_sk"
+	AddrSharedXPub               Bech32Prefix = "addr_shared_xvk"
+	AddrSharedXPrv               Bech32Prefix = "addr_shared_xsk"
+	AddrSharedExtendedPublicKey               = AddrSharedXPub
+	AddrSharedExtendedPrivateKey              = AddrSharedXPrv
+
+	AcctSharedPublicKey          Bech32Prefix = "acct_shared_vk"
+	AcctSharedPrivateKey         Bech32Prefix = "acct_shared_sk"
+	AcctSharedXPub               Bech32Prefix = "acct_shared_xvk"
+	AcctSharedXPrv               Bech32Prefix = "acct_shared_xsk"
+	AcctSharedExtendedPublicKey               = AcctSharedXPub
+	AcctSharedExtendedPrivateKey              = AcctSharedXPrv
+
+	RootSharedPublicKey          Bech32Prefix = "root_shared_vk"
+	RootSharedPrivateKey         Bech32Prefix = "root_shared_sk"
+	RootSharedXPub               Bech32Prefix = "root_shared_xvk"
+	RootSharedXPrv               Bech32Prefix = "root_shared_xsk"
+	RootSharedExtendedPublicKey               = RootSharedXPub
+	RootSharedExtendedPrivateKey              = RootSharedXPrv
+
+	StakeSharedPublicKey          Bech32Prefix = "stake_shared_vk"
+	StakeSharedPrivateKey         Bech32Prefix = "stake_shared_sk"
+	StakeSharedXPub               Bech32Prefix = "stake_shared_xvk"
+	StakeSharedXPrv               Bech32Prefix = "stake_shared_xsk"
+	StakeSharedExtendedPublicKey               = StakeSharedXPub
+	StakeSharedExtendedPrivateKey              = StakeSharedXPrv
+
+	// -- * Keys for 1855H
+	PolicyPublicKey          Bech32Prefix = "policy_vk"
+	PolicyPrivateKey         Bech32Prefix = "policy_sk"
+	PolicyXPub               Bech32Prefix = "policy_xvk"
+	PolicyXPrv               Bech32Prefix = "policy_xsk"
+	PolicyExtendedPublicKey               = PolicyXPub
+	PolicyExtendedPrivateKey              = PolicyXPrv
+)

credential.go

@@ -50,6 +50,14 @@ func NewKeyCredential(publicKey crypto.PubKey) (StakeCredential, error) {
 	return StakeCredential{Type: KeyCredential, KeyHash: keyHash}, nil
 }
 
+// NewKeyCredential creates a Key Credential from an AddrKeyHash (28 bytes key hash).
+func NewKeyCredentialFromHash(keyHash AddrKeyHash) (StakeCredential, error) {
+	if len(keyHash) < 28 {
+		return StakeCredential{}, fmt.Errorf("Wrong argument: expected 28 bytes key hash")
+	}
+	return StakeCredential{Type: KeyCredential, KeyHash: keyHash[:28]}, nil
+}
+
 // NewKeyCredential creates a Script Credential.
 func NewScriptCredential(script []byte) (StakeCredential, error) {
 	scriptHash, err := Blake224Hash(script)