WIP: go/common/crypto/sakg: Add ADR 0008 implementation

TODO: Add tests

go/common/crypto/sakg/sakg.go

@@ -0,0 +1,56 @@
+// Package sakg implements ADR 0008: Standard Account Key generation.
+package sakg
+
+import (
+	"fmt"
+
+	bip39 "github.com/tyler-smith/go-bip39"
+
+	"github.com/oasisprotocol/oasis-core/go/common/crypto/signature"
+	"github.com/oasisprotocol/oasis-core/go/common/crypto/slip10"
+)
+
+// MaxAccountKeyNumber is the maximum allowed key number when using ADR 0008.
+const MaxAccountKeyNumber = uint32(0x7fffffff)
+
+// BIP32PathPrefix is the Oasis Network's BIP-0032 path prefix as defined by
+// ADR 0008.
+var BIP32PathPrefix = "m/44'/474'"
+
+// Generate signer for the given mnemonic, passphrase and account according to
+// ADR 0008.
+func GetAccountSigner(
+	mnemonic string,
+	passphrase string,
+	number uint32,
+) (signature.Signer, BIP32Path, error) {
+	if number > MaxAccountKeyNumber {
+		return nil, nil, fmt.Errorf(
+			"sakg: invalid key number: %d (maximum: %d)",
+			number,
+			MaxAccountKeyNumber,
+		)
+	}
+
+	if !bip39.IsMnemonicValid(mnemonic) {
+		return nil, nil, fmt.Errorf("sakg: invalid mnemonic '%s'", mnemonic)
+	}
+
+	seed := bip39.NewSeed(mnemonic, passphrase)
+
+	signer, chainCode, err := slip10.NewMasterKey(seed)
+	if err != nil {
+		return nil, nil, fmt.Errorf("sakg: error deriving master key: %w", err)
+	}
+
+	path := NewBIP32Path(fmt.Sprintf("%s/%d'", BIP32PathPrefix, number))
+
+	for _, index := range path {
+		signer, chainCode, err = slip10.NewChildKey(signer, chainCode, index)
+		if err != nil {
+			return nil, nil, fmt.Errorf("sakg: error deriving child key: %w", err)
+		}
+	}
+
+	return signer, path, nil
+}

go/common/crypto/sakg/sakg_test.go

@@ -0,0 +1 @@
+package sakg

go/go.mod

@@ -51,6 +51,7 @@ require (
 	github.com/tendermint/tendermint v0.34.9
 	github.com/tendermint/tm-db v0.6.4
 	github.com/thepudds/fzgo v0.2.2
+	github.com/tyler-smith/go-bip39 v1.1.0
 	github.com/uber/jaeger-client-go v2.25.0+incompatible
 	github.com/uber/jaeger-lib v2.2.0+incompatible // indirect
 	github.com/whyrusleeping/go-logging v0.0.1

go/go.sum

@@ -946,6 +946,8 @@ github.com/tinylib/msgp v1.1.0 h1:9fQd+ICuRIu/ue4vxJZu6/LzxN0HwMds2nq/0cFvxHU=
 github.com/tinylib/msgp v1.1.0/go.mod h1:+d+yLhGm8mzTaHzB+wgMYrodPfmZrzkirds8fDWklFE=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
+github.com/tyler-smith/go-bip39 v1.1.0 h1:5eUemwrMargf3BSLRRCalXT93Ns6pQJIjYQN2nyfOP8=
+github.com/tyler-smith/go-bip39 v1.1.0/go.mod h1:gUYDtqQw1JS3ZJ8UWVcGTGqqr6YIN3CWg+kkNaLt55U=
 github.com/uber/jaeger-client-go v2.25.0+incompatible h1:IxcNZ7WRY1Y3G4poYlx24szfsn/3LvK9QHCq9oQw8+U=
 github.com/uber/jaeger-client-go v2.25.0+incompatible/go.mod h1:WVhlPFC8FDjOFMMWRy2pZqQJSXxYSwNYOkTr/Z6d3Kk=
 github.com/uber/jaeger-lib v2.2.0+incompatible h1:MxZXOiR2JuoANZ3J6DE/U0kSFv/eJ/GfSYVCjK7dyaw=