all: expect go1.20

This is kind of a fixup of b95dbca3c3

Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>

@@ -1,5 +1,5 @@
 .POSIX:
-.SILENT:
+#.SILENT:

@@ -0,0 +11,4 @@
+
+// Intn returns, as an int, a non-negative random number in the half-open interval [0,n).
+// It panics if n <= 0.
+func Intn(n byte) int {

@@ -0,0 +1,13 @@
+//go:build go1.20

@@ -0,0 +6,4 @@
+
+package sce
+
+func clear_slice(a []byte) {

@@ -0,0 +21,4 @@
+)
+
+// SceProfileFlags one flag for each potential element of an XEP-0420 envelope
+type SceProfileFlags struct {

@@ -0,0 +36,4 @@
+	Time    time.Time `xml:"time"`
+	To      jid.JID   `xml:"to"`
+	From    jid.JID   `xml:"from"`
+	// Content is expected to be a xml.TokenReader on Marshaling

@@ -0,0 +13,4 @@
+	"io"
+	"time"
+
+	"github.com/andreburgaud/crypt2go/padding"

@@ -0,0 +57,4 @@
+	ErrSceNSMismatch = errors.New(`XML Namespace of encrypted element does not match`)
+)
+
+func (env Envelope) startElement() xml.StartElement {

@@ -0,0 +69,4 @@
+}
+
+// MarshalXML satisfies the xml package's Marshaler interface.
+func (env Envelope) MarshalXML(e *xml.Encoder, _ xml.StartElement) error {

@@ -0,0 +210,4 @@
+
+// SceCrypter is an interface to en-/decrypt data
+type SceCrypter interface {
+	Encrypt(p []byte) ([]byte, error)

@@ -0,0 +277,4 @@
+}
+
+// SceEnvelope binds together an Envelope, the required XML Namespace, a crypto method and an optional header
+type SceEnvelope struct {

@@ -0,0 +350,4 @@
+}
+
+// XSFOMEMO2SceEncryptedEnvelope is declaring the structure of the XML document
+type XSFOMEMO2SceEncryptedEnvelope struct {

@@ -0,0 +47,4 @@
+// A list of potential errors returned by this package
+var (
+	// ErrSceProfileMissingFrom the SCE Profile requires a 'from' element, but none is given
+	ErrSceProfileMissingFrom = errors.New(`SCE Profile requires a 'from' element, but none is given`)

@@ -0,0 +205,4 @@
+}
+
+// AuthedCrypter is an interface for authenticated encryption
+type AuthedCrypter interface {