Add SHA256 fingerprint utils and helpers (#41)

helper/key.go

@@ -46,3 +46,12 @@ func GenerateKey(name, email string, passphrase []byte, keyType string, bits int
 	key.ClearPrivateParams()
 	return locked.Armor()
 }
+
+func GetSHA256Fingerprints(publicKey string) ([]string, error) {
+	key, err := crypto.NewKeyFromArmored(publicKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return key.GetSHA256Fingerprints(), nil
+}

helper/key_test.go

@@ -0,0 +1,18 @@
+package helper
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetSHA256FingerprintsV4(t *testing.T) {
+	sha256Fingerprints, err := GetSHA256Fingerprints(readTestFile("keyring_publicKey", false))
+	if err != nil {
+		t.Fatal("Cannot unarmor key:", err)
+	}
+
+	assert.Len(t, sha256Fingerprints, 2)
+	assert.Exactly(t, "d9ac0b857da6d2c8be985b251a9e3db31e7a1d2d832d1f07ebe838a9edce9c24", sha256Fingerprints[0])
+	assert.Exactly(t, "203dfba1f8442c17e59214d9cd11985bfc5cc8721bb4a71740dd5507e58a1a0d", sha256Fingerprints[1])
+}

helper/mobile.go

@@ -1,6 +1,8 @@
 package helper
 
 import (
+	"encoding/json"
+
 	"github.com/ProtonMail/gopenpgp/v2/crypto"
 )
 
@@ -65,3 +67,12 @@ func EncryptAttachment(plainData []byte, fileName string, keyRing *crypto.KeyRin
 	}
 	return decrypted, nil
 }
+
+func GetJsonSHA256Fingerprints(publicKey string) ([]byte, error) {
+	key, err := crypto.NewKeyFromArmored(publicKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return json.Marshal(key.GetSHA256Fingerprints())
+}

helper/mobile_test.go

@@ -53,3 +53,12 @@ func TestMobileSignedMessageDecryption(t *testing.T) {
 	assert.NotNil(t, err)
 	assert.Nil(t, decrypted)
 }
+
+func TestGetJsonSHA256FingerprintsV4(t *testing.T) {
+	sha256Fingerprints, err := GetJsonSHA256Fingerprints(readTestFile("keyring_publicKey", false))
+	if err != nil {
+		t.Fatal("Cannot unarmor key:", err)
+	}
+
+	assert.Exactly(t, []byte("[\"d9ac0b857da6d2c8be985b251a9e3db31e7a1d2d832d1f07ebe838a9edce9c24\",\"203dfba1f8442c17e59214d9cd11985bfc5cc8721bb4a71740dd5507e58a1a0d\"]"), sha256Fingerprints)
+}