osxkeychain: switch to github.com/keybase/go-keychain

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/keybase/go-keychain/util.go

@@ -0,0 +1,31 @@
+package keychain
+
+import (
+	"crypto/rand"
+	"encoding/base32"
+	"strings"
+)
+
+var randRead = rand.Read
+
+// RandomID returns random ID (base32) string with prefix, using 256 bits as
+// recommended by tptacek: https://gist.github.com/tqbf/be58d2d39690c3b366ad
+func RandomID(prefix string) (string, error) {
+	buf, err := RandBytes(32)
+	if err != nil {
+		return "", err
+	}
+	str := base32.StdEncoding.EncodeToString(buf)
+	str = strings.ReplaceAll(str, "=", "")
+	str = prefix + str
+	return str, nil
+}
+
+// RandBytes returns random bytes of length
+func RandBytes(length int) ([]byte, error) {
+	buf := make([]byte, length)
+	if _, err := randRead(buf); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}