patterns: Added Password Safe Version 3 pattern (#266)

* Add password safe V3

* Added description pragma

---------

Co-authored-by: Nik <werwolv98@gmail.com>

patterns/psafe3.hexpat

@@ -0,0 +1,33 @@
+// Password Safe V3
+// Only a small part of the file is unencrypted.
+
+#pragma endian little
+#pragma description Password Safe V3
+
+import std.mem;
+import std.sys;
+
+struct Prologue {
+    u8 SALT[32];
+    u32 ITER;
+    u8 HPP[32] [[name("H(P')")]];
+    u8 B1[16];
+    u8 B2[16];
+    u8 B3[16];
+    u8 B4[16];
+    u8 IV[16];
+};
+
+struct EOF {
+    u8 HMAC[32];
+};
+
+char magic[4] @ 0x00;
+std::assert(magic == "PWS3", "Invalid file: bad tag!");
+char marker[16] @ std::mem::size() - 48;
+std::assert(marker == "PWS3-EOFPWS3-EOF", "Invalid file: bad end marker!");
+
+Prologue prologue @ 0x04;
+u8 HMAC[32] @ std::mem::size() - 32;
+
+EOF eof @ std::mem::size() - 48;