add a didtest package for easier testing of DID based systems

Author: MichaelMure

didtest/didtest.go

@@ -0,0 +1,131 @@
+// Package didtest provides Personas that can be used for testing.  Each
+// Persona has a name, crypto.PrivKey and associated crypto.PubKey and
+// did.DID.
+package didtest
+
+import (
+	"encoding/base64"
+	"fmt"
+
+	"github.com/MetaMask/go-did-it"
+	didkeyctl "github.com/MetaMask/go-did-it/controller/did-key"
+	"github.com/MetaMask/go-did-it/crypto"
+	"github.com/MetaMask/go-did-it/crypto/ed25519"
+)
+
+const (
+	// all are ed25519 as base64
+	alicePrivKeyB64 = "zth/9cTSUVwlLzfEWwLCcOkaEmjrRGPOI6mOJksWAYZ3Toe7ymxAzDeiseyxbmEpJ81qYM3dZ8XrXqgonnTTEw=="
+	bobPrivKeyB64   = "+p1REV3MkUnLhUMbFe9RcSsmo33TT/FO85yaV+c6fiYJCBsdiwfMwodlkzSAG3sHQIuZj8qnJ678oJucYy7WEg=="
+	carolPrivKeyB64 = "aSu3vTwE7z3pXaTaAhVLeizuqnZUJZQHTCSLMLxyZh5LDoZQn80uoQgMEdsbOhR+zIqrjBn5WviGurDkKYVfug=="
+	danPrivKeyB64   = "s1zM1av6og3o0UMNbEs/RyezS7Nk/jbSYL2Z+xPEw9Cho/KuEAa75Sf4yJHclLwpKXNucbrZ2scE8Iy8K05KWQ=="
+	erinPrivKeyB64  = "+qHpaAR3iivWMEl+pkXmq+uJeHtqFiY++XOXtZ9Tu/WPABCO+eRFrTCLJykJEzAPGFmkJF8HQ7DMwOH7Ry3Aqw=="
+	frankPrivKeyB64 = "4k/1N0+Fq73DxmNbGis9PY2KgKxWmtDWhmi1E6sBLuGd7DS0TWjCn1Xa3lXkY49mFszMjhWC+V6DCBf7R68u4Q=="
+)
+
+// Persona is a generic participant used for cryptographic testing.
+type Persona int
+
+// The provided Personas were selected from the first few generic
+// participants listed in this [table].
+//
+// [table]: https://en.wikipedia.org/wiki/Alice_and_Bob#Cryptographic_systems
+const (
+	PersonaAlice Persona = iota + 1
+	PersonaBob
+	PersonaCarol
+	PersonaDan
+	PersonaErin
+	PersonaFrank
+)
+
+var privKeys map[Persona]crypto.PrivateKeySigningBytes
+
+func init() {
+	privKeys = make(map[Persona]crypto.PrivateKeySigningBytes, 6)
+	for persona, pB64 := range privKeyB64() {
+		privBytes, err := base64.StdEncoding.DecodeString(pB64)
+		if err != nil {
+			return
+		}
+
+		privKey, err := ed25519.PrivateKeyFromBytes(privBytes)
+		if err != nil {
+			return
+		}
+
+		privKeys[persona] = privKey
+	}
+}
+
+// DID returns a did.DID based on the Persona's Ed25519 public key.
+func (p Persona) DID() did.DID {
+	return didkeyctl.FromPrivateKey(p.PrivKey())
+}
+
+// Name returns the username of the Persona.
+func (p Persona) Name() string {
+	name, ok := map[Persona]string{
+		PersonaAlice: "Alice",
+		PersonaBob:   "Bob",
+		PersonaCarol: "Carol",
+		PersonaDan:   "Dan",
+		PersonaErin:  "Erin",
+		PersonaFrank: "Frank",
+	}[p]
+	if !ok {
+		panic(fmt.Sprintf("Unknown persona: %v", p))
+	}
+
+	return name
+}
+
+// PrivKey returns the Ed25519 private key for the Persona.
+func (p Persona) PrivKey() crypto.PrivateKeySigningBytes {
+	res, ok := privKeys[p]
+	if !ok {
+		panic(fmt.Sprintf("Unknown persona: %v", p))
+	}
+	return res
+}
+
+// PubKey returns the Ed25519 public key for the Persona.
+func (p Persona) PubKey() crypto.PublicKey {
+	return p.PrivKey().Public()
+}
+
+func privKeyB64() map[Persona]string {
+	return map[Persona]string{
+		PersonaAlice: alicePrivKeyB64,
+		PersonaBob:   bobPrivKeyB64,
+		PersonaCarol: carolPrivKeyB64,
+		PersonaDan:   danPrivKeyB64,
+		PersonaErin:  erinPrivKeyB64,
+		PersonaFrank: frankPrivKeyB64,
+	}
+}
+
+// Personas returns an (alphabetically) ordered list of the defined
+// Persona values.
+func Personas() []Persona {
+	return []Persona{
+		PersonaAlice,
+		PersonaBob,
+		PersonaCarol,
+		PersonaDan,
+		PersonaErin,
+		PersonaFrank,
+	}
+}
+
+// DidToName retrieve the persona's name from its DID.
+func DidToName(d did.DID) string {
+	return map[did.DID]string{
+		PersonaAlice.DID(): "Alice",
+		PersonaBob.DID():   "Bob",
+		PersonaCarol.DID(): "Carol",
+		PersonaDan.DID():   "Dan",
+		PersonaErin.DID():  "Erin",
+		PersonaFrank.DID(): "Frank",
+	}[d]
+}