
Copyright (c) 2003-2020 Rony Shapiro <ronys@pwsafe.org>.
All rights reserved. Use of the code is allowed under the Artistic
License terms, as specified in the LICENSE file distributed with this
code, or available from
http://www.opensource.org/licenses/artistic-license-2.0.php 

Following is a description of the "v1.9" file format. For v2 and v3
formats, see the formatv2.txt and formatv3.txt files, respectively.

v1.9 files are arranged as follows:

RND|H(RND)|SALT|IP|Name1|Password1|Notes1|...|NameN|PasswordN|NotesN

Where:

RND is an 8 byte random value, used along with H(RND) to quickly
verify the password.

H(RND) is SHA1_init_state_zero(Cipher(RND)|{0x00,0x00});
       tempSalt = SHA1(RND|{0x00,0x00}|password);
       Cipher(RND) is 1000 encryptions of RND, with tempSalt as the
       encryption key. In short, a kind of HMAC dependant on the
       password. Written before the HMAC RFC came out, no good reason
       to change. (If it ain't broke...)

SHA1_init_state_zero() is the same as the normal SHA1 but the initial
state of the hash is all zero's instead of the proscribed initial
values (0x67452301, 0xEFCDAB89 and so forth). This (as well as the two
zero bytes passed to SHA1) is an apparent artifact (bug?) of the
original implementation. Changing it now would break all existing
databases...

[Thanks to Nicolas Dade for refining the above description - see
https://sourceforge.net/forum/message.php?msg_id=2387939]
[Thanks again to Jason Diamond for correcting my correction (private
correspondence)]

SALT is the salt used for encrypting the data (you know, to protect
against dictionary attacks)

IP is the initial initialization vector value

Name, Password & Notes are stored sequentially as 8 byte blocks, with
the first block holding an int with the length (in bytes) of the
actual value, which follows immediately.

Apparently as a hack to upgrade from previous versions, the Name field
is actually two fields, "Title" and "Username", separated by
SPLTCHR. Furthermore, if the Username is DEFUSERCHR, then it is
replaced by the user's "default user name", as specified in
options. It works, but is not a pretty sight.

End of Format description.
