drive-by: unit tests had become much too slow, switch back to have a …

…special path to generate test keys and use a shorter length there

asserts/crypto.go

@@ -303,15 +303,19 @@ func OpenPGPPrivateKey(privk *packet.PrivateKey) PrivateKey {
 	return openpgpPrivateKey{privk}
 }
 
-// GenerateKey generates a private/public key pair.
-func GenerateKey() (PrivateKey, error) {
-	priv, err := rsa.GenerateKey(rand.Reader, 4096)
+func generateKey(bits int) (PrivateKey, error) {
+	priv, err := rsa.GenerateKey(rand.Reader, bits)
 	if err != nil {
 		return nil, err
 	}
 	return OpenPGPPrivateKey(packet.NewRSAPrivateKey(time.Now(), priv)), nil
 }
 
+// GenerateKey generates a private/public key pair.
+func GenerateKey() (PrivateKey, error) {
+	return generateKey(4096)
+}
+
 func encodePrivateKey(privKey PrivateKey) ([]byte, error) {
 	return encodeKey(privKey, "private key")
 }

asserts/export_test.go

@@ -28,6 +28,9 @@ import (
 
 // expose test-only things here
 
+// GenerateTestKey lets the test generate keys of given length
+var GenerateTestKey = generateKey
+
 // access internal openpgp lib packet
 func PrivateKeyPacket(pk PrivateKey) *packet.PrivateKey {
 	return pk.(openpgpPrivateKey).privk

asserts/privkeys_for_test.go

@@ -35,7 +35,11 @@ var (
 )
 
 func genTestPrivKey() asserts.PrivateKey {
-	privKey, err := asserts.GenerateKey()
+	// use a shorter key length here for test key because otherwise
+	// they take too long to generate;
+	// the ones that care use pregenerated keys of the right length
+	// or use GenerateKey directly
+	privKey, err := asserts.GenerateTestKey(752)
 	if err != nil {
 		panic(fmt.Errorf("failed to create priv key for tests: %v", err))
 	}