1 files changed, 63 insertions, 0 deletions
diff --git a/src/parabola_hackers/password.go b/src/parabola_hackers/password.go
new file mode 100644
index 0000000..4ea345f
--- /dev/null
+++ b/src/parabola_hackers/password.go
@@ -0,0 +1,63 @@
+// Copyright 2015-2016 Luke Shumaker <lukeshu@sbcglobal.net>.
+//
+// This is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public
+// License along with this manual; if not, see
+// <http://www.gnu.org/licenses/>.
+
+package parabola_hackers
+
+import (
+	"io/ioutil"
+	"lukeshu.com/git/go/libgnulinux.git/crypt"
+	"fmt"
+	"os"
+	"strings"
+)
+
+/* Note that the password hash value should be one of:
+   <empty> - no password set, allow login without password
+   !       - used to prevent logins
+   x       - "valid" encrypted password that does not match any valid password
+             often used to indicate that the password is defined elsewhere
+   other   - encrypted password, in crypt(3) format */
+
+func LoadUserPassword(filename string) (hash string, err error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return
+	}
+	contents, err := ioutil.ReadAll(file)
+	if err != nil {
+		return
+	}
+	lines := strings.Split(string(contents), "\n")
+	switch len(lines) {
+	case 1:
+		hash = lines[0]
+	case 2:
+		if lines[1] == "" {
+			hash = lines[0]
+		} else {
+			err = fmt.Errorf("Invalid password format in file: %q", filename)
+		}
+	default:
+		err = fmt.Errorf("Invalid password format in file (number of lines): %q", filename)
+		return
+	}
+	if hash != "!" && !crypt.SaltOk(hash) {
+		hash = "!"
+		err = fmt.Errorf("Invalid password format in file (invalid salt): %q", filename)
+		return
+	}
+	return
+}