Skip to main content

Integrating OpenSSL crypto functions with Go

In a previous post I pointed to my go-openssl project that provides alternative implementations of crypto/rc4, crypto/md5 and crypto/sha1 based on OpenSSL's libcrypto. To make these easy to use (and to allow Go itself to use them for crypto/tls) I've added a bootstrapping Makefile to the project that builds Go itself with the OpenSSL implementations integrated.

To use it just do make in the integrate directory. It will create a go subdirectory with a full build of the latest version of Go form Mercurial incorporating the OpenSSL implementations. Doing make tester will build a small tester program that exercises the new hash and cipher implementations.

Since this was a slightly complex task (requiring the assistance of minux) I wrote a large comment in the Makefile. If anyone else needs to patch Go itself they might run into similar things: 
# This target modifies the Go installation in the following ways:                     
#                                                                                     
# 1. Copies the native Go md5 implementation and calls it crypto/gomd5                
#                                                                                     
# 2. Alters cgo so that it uses crypto/gomd5 and fixes gomd5 so that                  
#    it doesn't reference crypto/md5                                                     
#                                                                                     
# 3. Alters the deps_test.go to recognize that the OpenSSL-linked                     
#    versions of md5, sha1 and rc4 are dependent on the C include.                    
#                                                                                     
# 4. Modifies the api/except.txt list to cause the change in signature                
#    on the md5, sha1 and rc4 packages to be ignored when testing API                 
#    compatibility (this is necessary because using cgo changes the                   
#    signature even though they are compatible with the existing                      
#    packages)                                                                        
#                                                                                     
# 5. Deletes the md5block.go and sha1block.go implementations since                   
#    they are not needed.                                                             
#                                                                                     
# 6. Copies in the OpenSSL md5, sha1 and rc4.

Comments

Post a Comment

Popular posts from this blog

How to write a successful blog post

First, a quick clarification of 'successful'. In this instance, I mean a blog post that receives a large number of page views. For my, little blog the most successful post ever got almost 57,000 page views. Not a lot by some other standards, but I was pretty happy about it. Looking at the top 10 blog posts (by page views) on my site, I've tried to distill some wisdom about what made them successful. Your blog posting mileage may vary. 1. Avoid using the passive voice The Microsoft Word grammar checker has probably been telling you this for years, but the passive voice excludes the people involved in your blog post. And that includes you, the author, and the reader. By using personal pronouns like I, you and we, you will include the reader in your blog post. When I first started this blog I avoid using "I" because I thought I was being narcissistic. But we all like to read about other people, people help anchor a story in reality. Without people your bl
9 comments
Read more

Your last name contains invalid characters

My last name is "Graham-Cumming". But here's a typical form response when I enter it: Does the web site have any idea how rude it is to claim that my last name contains invalid characters? Clearly not. What they actually meant is: our web site will not accept that hyphen in your last name. But do they say that? No, of course not. They decide to shove in my face the claim that there's something wrong with my name. There's nothing wrong with my name, just as there's nothing wrong with someone whose first name is Jean-Marie, or someone whose last name is O'Reilly. What is wrong is that way this is being handled. If the system can't cope with non-letters and spaces it needs to say that. How about the following error message: Our system is unable to process last names that contain non-letters, please replace them with spaces. Don't blame me for having a last name that your system doesn't like, whose fault is that? Saying "Your
63 comments
Read more

The Elevator Button Problem

User interface design is hard. It's hard because people perceive apparently simple things very differently. For example, take a look at this interface to an elevator: From flickr Now imagine the following situation. You are on the third floor of this building and you wish to go to the tenth. The elevator is on the fifth floor and there's an indicator that tells you where it is. Which button do you press? Most people probably say: "press up" since they want to go up. Not long ago I watched someone do the opposite and questioned them about their behavior. They said: "well the elevator is on the fifth floor and I am on the third, so I want it to come down to me". Much can be learnt about the design of user interfaces by considering this, apparently, simple interface. If you think about the elevator button problem you'll find that something so simple has hidden depths. How do people learn about elevator calling? What's the right amount of
54 comments
Read more