Readme

README.md

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+# Introduction
+CryptCheck is a Ruby toolbox that help anybody to check for cryptography security
+level and best practices compliance.
+
+CryptCheck is released under
+[AGPLv3+](https://www.gnu.org/licenses/agpl-3.0.en.html) license.
+
+# Preliminary warning
+**/!\ This tool use custom weak builds of OpenSSL library and OpenSSL Ruby extension /!\**.
+
+Those builds are cryptographically weaken to be able to test for (very) weak and
+today totally deprecated ciphers.
+
+Don’t deploy it on production machine to avoid any security troubles, or use VM
+to isolate them !
+
+# Setup
+## Ruby
+You need a fully operationnal Ruby stack.
+Because of the warning above, don’t use your system Ruby.
+
+I recommend to use [RBEnv](https://github.com/sstephenson/rbenv) and it
+[Ruby-build](https://github.com/sstephenson/ruby-build) plugin to build a new
+ruby environment instead of your system one.
+
+Currently supported Ruby stack is v2.2.2.
+
+## OpenSSL library and Ruby extension
+To be able to test for (very) weak ciphers and to have access to DH parameters,
+CryptCheck need custom build of OpenSSL library and patched build of OpenSSL Ruby
+extension.
+
+
+Once you have cloned CryptCheck repository, just run `make` inside to
+build the needed libraries.
+
+If `make` fails with the following error :
+```
+make: *** No rule to make target 'lib/libssl.so.1.0.0', needed by 'libs'.  Stop.
+```
+just run again `make` (if you understand this problem, contact me !).
+
+The built libraries (*libcrypto.so*, *libssl.so* and *openssl.so*) are located
+under the *lib* directory.<br/>
+CryptCheck use *LD_LIBRARY_PATH* and Ruby load path hack to inject those weaken
+libraries instead of the system ones.
+
+## Ruby dependencies
+CryptCheck relies on few Ruby libraries, managed with [Bundler](http://bundler.io/).
+
+To fetch and install them, just run `bundle install`.
+
+# Usage
+Simply run the corresponding runner of what you want to test :
+
+ * HTTPS : ```bin/check_https example.org```
+ * XMPP : ```bin/check_xmpp example.org```
+ * SMTP : ```bin/check_smtp example.org```
+
+If you want more information of what is going on under the hood, run the command
+with debug enabled, like ```bin/check_https example.org debug```
+
+## Understanding results
+Rank goes from "A+" (perfect) to "F" (very weak).<br/>
+"M" means your certificate and your hostname mismatch.<br/>
+"T" means your certificate is not issued by a valid root certificate authority.
+
+Only a perfect setup gets a perfect score and a "A" rank :).<br/>
+"A" score is based on [RFC 7525](https://tools.ietf.org/html/rfc7525) recommandations.
+
+ * Protocol
+   * SSL (v2 and v3) are totally [deprecated](https://tools.ietf.org/html/rfc7568)
+     now, because of very serious known vulnerabilities
+     ([Poodle](https://www.openssl.org/~bodo/ssl-poodle.pdf)…).
+     Using one of them cap your rank to "F".
+   * TLSv1 and TLSv1.1 suffer of the
+     [Poodle TLS](https://community.qualys.com/blogs/securitylabs/2014/12/08/poodle-bites-tls)
+     vulnerability.
+   * TLSv1.2 is the only remaining protocol with no known vulnerabilities, so if
+     you don’t support it, your rank is cap to "B".
+ * Key size
+   * If you use certificate key less than 2048 bits, your rank is cap to "B".
+ * Ciphers
+   * Very weak ciphers, including MD5 hash, anonymous DH parameters, NULL ciphers 
+     (yes, it exits…), export ciphers ([Freak](https://freakattack.com/)) or weak 
+     ciphers (RC4, DES…) cap your rank to "F".
+   * 3DES is considered weak and must be avoided, using it cap your score to "C".
+
+ * Score
+   * Protocol score is based on the **weakest** protocol you support :<br/>
+     SSLv2 = 0, SSLv3 = 20, TLSv1 = 60, TLSv1.1 = 80, TLSv1.2 = 100.
+   * Key score is based on your certificate key size :<br/>
+     <512 = 10, <1024 = 20, <2048 = 50, <4096 = 90, ≥4096 = 100.
+   * Cipher score is based on the **weakest** cipher you support :<br/>
+     0 = 0, <112 = 10, <128 = 50, <256 = 90, ≥256 = 100.
+   * Overall score is based on the other scores :<br/>
+     overall = 0.3 * protocol + 0.3 * key + 0.4 * cipher
+
+ * Best practices
+   * PFS : you gain this flag when you support **only**
+     [perfect forward secrecy](https://en.wikipedia.org/wiki/Forward_secrecy)
+     ciphers (DHE or ECDHE)
+   * HSTS : you gain this flag when you protect yourself with
+     [HTTP Strict Transport Security](https://tools.ietf.org/html/rfc6797).
+   * Long HSTS : you gain this flag when you support HSTS with a duration of at
+     least 6 monthes.
+
+ * Rank
+   * Rank is based on your overall score and above caps :<br/>
+     <20 = F, <35 = E, <50 = D, <65 = C, <80 = B, ≥80 = A.
+   * If you get an "A" and you have all the best practices above, you get "A+".