I gave myself a 1Q2019 target to write proper READMEs for my Github repos. First up is PasswordCrypt. I reproduce the README here.
PasswordCrypt is a library for Pharo Smalltalk to handle passwords salted and hashed by SHA-256/SHA-512. Its primary components are PCPasswordCrypt, PCAuthenticator and PCBasicAuthenticator.
At its core, PCPasswordCrypt provides the following class-side messages:
PCPasswordCrypt sha256crypt: 'secret' withSalt: 'andPepperToo' "'$5$andPepperToo$5p0MWgRMT6l6EA6dYDlFhuQKi.tfCXNd35T99HxbsTD'"
The result is a string in modular crypt format (MFC).
$5 on the left of the
string indicates that the hashing algorithm is SHA-256. For SHA-512, the
On the instance side, PCPasswordCrypt generates the salt randomly if one is not supplied:
PCPasswordCrypt new sha256crypt: 'secret' "'$5$5bUAI5i2$iIdIXcQGhZfNF0HQFG592Ut1I6UtuO/smBPJkKBrRzC'"
PCAuthenticator builds on PCPasswordCrypt to provide username/password management. PCAuthenticator operates as a singleton object to persist its data in the Pharo image across restarts.
| appName auth newUser userToValidate | appName := 'myApp'. "Initialize the authenticator for my application." auth := PCAuthenticator uniqueInstance. auth initializeDatabaseFor: appName. "Add a user." newUser := PCUserCredential appname: appName; username: 'testuser'; password: 'secret'; yourself. auth insertUserCredential: newUser. "Create another user object and validate its password." userToValidate := PCUserCredential appname: appName; username: 'testuser'; password: 'secret'; yourself. auth validateUserCredential: userToValidate "If the passwords match, userToValidate is returned; otherwise, nil is returned."
PCAuthenticatorUI is a simple Spec-based user interface to upsert new usernames/passwords into PCAuthenticator. I wrote it because I simply abhor code snippets containing clear-text passwords, except for demonstration as above. To run PCAuthenticatorUI:
PCAuthenticatorUI new openWithSpec
PCBasicAuthenticator subclasses ZnBasicAuthenticator, the HTTP basic authentication handler in ZincHTTPComponents. It uses PCAuthenticator so that
To install the Pharo code:
Metacello new baseline: 'PasswordCrypt'; repository: 'github://PierceNg/PasswordCrypt/src-st'; load.
PCPasswordCrypt is an FFI to the C library
libshacrypt, built from the
shacrypt512.c in the directory
src-c. To build the C library:
% cd src-c % make
The generated shared library is
libshacrypt.so on Linux and
libshacrypt.dylib on OSX/macOS. It must be placed where the Pharo VM can
find it at run time. My practice is to place the shared library file together
with the Pharo VM's plugins. On macOS, suppose Pharo is installed in
libshacrypt.dylib goes into
sha512crypt.care public domain
I've just added RIPEMD160 to the EVP interface in OpenSSL-Pharo. This post serves as a HOWTO.
OpenSSL's C interface defines RIPEMD160 thusly:
Create LcLibCrypto>>apiEvpRIPEMD160 for it:
Next, create LcEvpRIPEMD160 as a subclass of LcEvpMessageDigest:
Add class-side accessors:
I've migrated OpenSSL-Pharo to Github.
OpenSSL-Pharo now works on Windows. Tested on Windows 10 with a fresh 32-bit Pharo 6.1 zip package downloaded from pharo.org. On Windows this library uses libeay.dll which is bundled with the Pharo VM.
I've put up the beginnings of a wrapper for OpenSSL on STH:
Verified on Pharo 6 32- and 64-bit.
My near term goal is to wrap enough libcrypto functionality to implement the client-side of Let's Encrypt.
I meant to put it up on GH, for the ease of forking and PRs, but I couldn't get Iceberg to work, and gitfiletree also failed to load, so STH it is for now.
In the GH repo, C source files are in the src-c directory. Compile with the Makefile there. Move the .so or .dylib file to where the VM can find it.
To load the Smalltalk code, in a Pharo playground:
Run the tests in TestRunner. Provided the Pharo VM can find the shared library, all 12 tests should pass.
This version adds an authentication database that uses in-image persistence, accessed programmatically via the PCAuthenticator uniqueInstance, and a very simple user interface invoked thusly:
Currently PCAuthenticator hardcodes to SHA256. It should be straightforward to make the hashing algorithm pluggable, including from other shared libraries. Hosting on GH makes it easier for forks and PRs.
SQLcipher "is an open source extension to SQLite that provides transparent 256-bit AES encryption of database files." SQLcipher provides the same API as the SQLite Encryption Extension (SEE) by D Richard Hipp, the original developer of SQLite.
I've added SQLcipher/SEE's API to NBSQLite3. By convention, on Unix, SQLcipher produces a shared library named libsqlcipher.so, while the SQLite shared library is named libsqlite3.so. NBSQLite3 switches between the two libraries based on the messages #beSQLcipher and #beSQLite to the NBSQLite3FFI class.
Here's a demonstration code snippet using the keying pragma in SQL:
NBSQLcipherExample class>>examplePragma contains a longer version of the above snippet that includes reopening the encrypted database file without the keying pragma and using the SQLite library.
Tested on Linux Mint. Code updated in Smalltalk Hub. Some refactoring to be expected, because the above snippet using the keying pragma is the only test I've done.
% openssl sha256 libsqlcipher.so SHA256(libsqlcipher.so)= 441cbc559a4f38a018121c6d86caa0cf0fb2c5b2a57c353cc09a4e048ec8ebe8 % ldd libsqlcipher.so linux-gate.so.1 => (0xf77da000) libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xf7569000) libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xf754d000) libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xf739e000) /lib/ld-linux.so.2 (0xf77dd000)
For good measure, I've also put up a copy of sqlcipher built at the same time. It requires readline.
% openssl sha256 sqlcipher SHA256(sqlcipher)= 4ccb3cf2064d41675406a55c8404a8877a40541dd9830009f4c0e203468e3d7b % ldd sqlcipher linux-gate.so.1 => (0xf770a000) libreadline.so.6 => /lib/i386-linux-gnu/libreadline.so.6 (0xf76a7000) libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xf76a2000) libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xf7685000) libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xf74d7000) libtinfo.so.5 => /lib/i386-linux-gnu/libtinfo.so.5 (0xf74b5000) /lib/ld-linux.so.2 (0xf770d000)
According to its documentation, on Unix, the Pharo VM's SSL plugin, libSqueakSSL.so, links into OpenSSL libraries dynamically. On my 64bit Ubuntu Trusty machine, OpenSSL is provided by the libssl1.0.0:i386 package.
(By the way, the SSH2 plugin libssh2.so.1.0.1 requires libcrypto too.)
According to packages.ubuntu.com, Trusty's libssl1.0.0 is built from openssl_1.0.1f.orig.tar.gz plus successive upstream patches.
From the OpenBSD developers, LibreSSL is "a version of the TLS/crypto stack forked from OpenSSL in 2014, with goals of modernizing the codebase, improving security, and applying best practice development processes." LibreSSL also comes with libtls, "a new TLS library, designed to make it easier to write foolproof applications".
Let's see how we go about linking libSqueakSSL.so with LibreSSL.
First, download and unpack LibreSSL. Modify the configure script at lines 2287 and 2289 so that LIBCRYPTO_VERSION and LIBSSL_VERSION both say 1:0:0 instead of 35:0:0. Then build LibreSSL:
I'm building on a 64bit OS, hence "-m32". Without "--disable-asm", the build fails. To get the assembler version, which is recommended for serious usage, either set up a 32bit build environment or muck around with autoconf/configure. I suspect the former is easier. :-)
The output files are $SRC/crypto/.libs/libcrypto.so.1.0.0 and $SRC/ssl/.libs/libssl.so.1.0.0. The shared object files have the "1.0.0" suffix because I modified configure above. Alternatively, I could've played around with autoconf, or built the shared objects with the "35.0.0" suffix and sym/hard-link them for the "1.0.0" versions. TIMTOWTDI.
Next, remove the OpenSSL package:
Finally, put the LibreSSL shared object files into the right place. Where this right place is depends on your environment. TIMTOWTDI. I choose to put them in the Pharo VM directory with its other plugins, and arrange to start Pharo with LD_LIBRARY_PATH set appropriately. Going by the output of ldd again, the following is required:
Launch the Pharo 4.0 image and run the Zodiac tests. All tests should pass. Well, except testGetPharoVersion, which looks for a file that apparently no longer exists.
Incidentally, Squeak 5.0-All-in-One's SSL plugin appears to have linked its crypto/SSL libraries in statically, so the only way to upgrade is to build a new plugin.
Here's an example Jx9 program:
And here's Smalltalk code to execute the above Jx9 program:
PunQLite supports extracting values from an executed Jx9 program, as in "exe @ 'sid'" above. PunQLite currently does not support UnQLite's APIs for exchanging JSON objects between Smalltalk and an Jx9 program which provide functionality similar to parameter binding in SQL APIs. That means Jx9 programs, including data to be stored, has to be constructed from strings... As OWASP says about NoSQL injection:
Because these NoSQL injection attacks may execute within a procedural language, rather than in the declarative SQL language, the potential impacts are greater than traditional SQL injection.
I bought a Yubikey device and am going to write a Pharo library for it. Meanwhile, I discovered that Richard Prinz has an implementation of RFC 6536 Time-based One Time Passwords for Pharo.
Recently, Adobe was hacked, resulting in, among other breakages, the loss of 130 million passwords. It was revealed that the passwords were encrypted using ECB, electronic cookbook mode, which is a rather poor way of securing passwords.
The MacRumors forum site was also hacked recently. The site runs the vBulletin forumware, which protects passwords using md5crypt.
md5crypt is a password hashing scheme devised by Poul-Henning Kamp in 1995. The hashed password takes the format $1$<salt>$<password-hash>. The hash is designed to be expensive to compute, to slow down attacks. In 2012, Poul-Henning announced that md5crypt was no longer considered safe, in view of advances in computing power.
sha-crypt, from Ulrich Depper, is a public domain implementation of SHA-256/512-based password hashing, which works similarly to md5crypt, using SHA-256/512 and allowing an arbitrary number of rounds through the hashing algorithm.
The following commands build and run sha(256|512)crypt.c as self-test programs:
Next, build shared library:
Move the .so or .dylib file to where your plugins are.
PCPasswordCrypt is a Smalltalk interface to libshacrypt using NativeBoost. It is very simple to use:
Tested on OSX (Mountain Lion) and Linux (Mint 14). The C programs work on FreeBSD, but my self-built FreeBSD Cog VM doesn't have NativeBoost.
NaCl (pronounced "salt") is a new, easy to use high-speed software library for network communication, encryption, decryption, signatures, etc. It uses elliptic curve cryptography. libsodium is a portable fork of NaCl. Crypto-Nacl is a Pharo/Squeak interface to libsodium. It uses FFI. As is, the library should be named liblibsodium.dylib when used with Crypto-Nacl on OSX.
SqueakSSL is a plugin to the platform-native SSL/TLS facility. The plugin is bundled with the Cog VM. Zodiac is an open source, cross-Smalltalk implementation of regular and secure socket streams. Zodiac uses SqueakSSL. Webclient also uses SqueakSSL to support HTTPS.
Online examples of SQL database APIs tend to go like this:
Perhaps fine for pedagogical material, and I do the same during development. However, I don't want that for production - hardcoding a database (or any) password in application code simply offends my sensibilities.
Secret splitting divides a message into a number of pieces. In the simplest scheme, all the pieces are required to reconstruct the message. To split the message into, say, 5 pieces, generate 4 random strings, each of the same length as the message, then XOR the message and the random strings together. Save the random strings and the final XOR output. To reconstruct the message, XOR the 5 pieces of saved data.
I've written a package called SpsSplitPasswordStore that implements the simple secret splitting scheme described above. The motivation is to avoid both hardcoding the database password in application code and saving the password in clear text in a file.
The following saves a password:
The file 'sps1.dat' doesn't particularly look like it contains a password. (Yes, security through obscurity, I know.)
This code reconstructs the password:
Thus the database connection preparation code becomes like this:
The security claim I make for SpsSplitPasswordStore is that it is more secure than hardcoding your database username/password pair in your application code.
While convenience usually trumps security in the real world, in this case, SpsSplitPasswordStore also makes it more convenient to change the application's database password without requiring changes to the application.
Edit: Available at http://ss3.gemtalksystems.com/ss/SpsSplitPasswordStore.html.
The OWASP Zed Attack Proxy, also known as ZAP, "is an easy to use integrated penetration testing tool for finding vulnerabilities in web applications."
Download, unpack, run "./zap.sh", and away we go attacking my blog search interface:
ZAP fuzzes the search parameter. And finds something interesting: "200 OK" is expected, as is "404 Not Found". But "500 Internal Server Error" isn't!
However, Pharo, Zinc and my blog server kept running though, so the 500 wasn't because the server crashed. Indeed, ZAP reports the response thusly:
Aha! This is an SQLite error: "The database file is locked". Here is one possible StackOverflow explanation. I'll have to verify if that is indeed the cause.
ZAP also offers an SQL injection fuzzer with even more attacks:
Through all this, the server kept running. Although attacks like "insert into mysql.user (u..." and "exec sp_addlogin 'name'..." returned "Successful", my backend is SQLite and these don't apply.
Still, some time ago while doodling with SQLite, I manage to lock up an image such that it crashes instantly upon re-opening. I haven't found the reason. My conjecture is that it is related to my code's not doing FFI properly, although at this time I have no idea how to test this. I'll probably keep banging on the SQLite interface to see if it eventually kills the image.
I've previously written about StackOverflow full text indexing using SQLite. I've now loaded this site's small body of content into an SQLite FTS database, and have implemented a search interface for it. Before opening up the search interface to the big bad Internet, I reckon some testing is required.
Fuzzing "is a black box software testing technique which basically consists of finding implementation bugs using malformed/semi-malformed data injection in an automated fashion." This site runs as a Zinc server delegate in Pharo Smalltalk. In fuzzing the search interface, I will be fuzzing Zinc's input handling, my server delegate's input handling including its susceptibility to SQL injection, and possibly the CogVM FFI that hooks Pharo up with SQLite.
Of course, the Smalltalk image is not a black box. While fuzzing I will be able to view Zinc's source code, explore live objects, and check behaviour.