lib: MTPpasswordResetToken

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/rng.go b/lib/rng.go
index c1038f4..c48f719 100644
--- a/lib/rng.go
+++ b/lib/rng.go
@@ -142,3 +142,25 @@ func MTXORStream(stream, seed []byte) []byte {
 	}
 	return s
 }
+
+func MTPasswordResetToken(seed uint32, length int) string {
+	if length < 16 {
+		length = 16 // Default length.
+	}
+
+	// Init MT19937.
+	mtR := new(MTRand)
+	mtR.Seed(seed)
+
+	n := uint32(0)
+	t := make([]byte, 0) // Token in bytes.
+	for i := 0; i < length; i++ {
+		if n == uint32(0) {
+			n = mtR.Extract()
+		}
+		t = append(t, byte(n&0xFF)) // Extract last 8 bits.
+		n = n >> 8                  // Get rid of the last 8 bits.
+	}
+
+	return BytesToHexStr(t) // Return token as a hex string.
+}