# Amazon Product API hmac signature? **URL:** \ **Category:** Ruby\ **Created:** [May 11, 2009, 3:54am UTC](https://www.ruby-forum.com/t/amazon-product-api-hmac-signature/167650 "2009-05-11T03:54:18Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [May 11, 2009, 3:54am UTC](https://www.ruby-forum.com/t/amazon-product-api-hmac-signature/167650/1 "2009-05-11T03:54:18Z")
So, starting August 15th, the Amazon product web service API (the one where you can get info about amazon products, manipulate wishlists and shopping carts, etc), is going to require a form of cryptographic signature on all requests. [http://docs.amazonwebservices.com/AWSECommerceService/latest/DG/](http://docs.amazonwebservices.com/AWSECommerceService/latest/DG/) I think I can put everything together from various gems. But it’s kind of picky (for instance, you have to make sure to CGI-escape in exactly the right way and not over-escape at certain points). I’m wondering if anyone knows if anyone’s already tackled this, and maybe has a gem with tests that’ll do it for you? Maybe part of some larger amazon-interaction gem or something? This authentication method has been used with other AWS apis for a while now I think. But I can’t find anything. If not, and I write it, do you all think it would be a good thing to distribute as a gem? It probably won’t be very many lines of code, but making sure you’ve got the _right_ few lines of code that don’t have any bugs in them is the trick. Thanks for any advice, Jonathan ---
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [May 11, 2009, 4:18am UTC](https://www.ruby-forum.com/t/amazon-product-api-hmac-signature/167650/2 "2009-05-11T04:18:41Z")
On Sun, May 10, 2009 at 6:54 PM, Jonathan R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > I’m wondering if anyone knows if anyone’s already tackled this, and > maybe has a gem with tests that’ll do it for you? Maybe part of some > larger amazon-interaction gem or something? This authentication method > has been used with other AWS apis for a while now I think. But I can’t > find anything. Both RightAWS and AWS::S3 have code to sign requests. I’d start there. Ben ---
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [August 10, 2009, 10:54am UTC](https://www.ruby-forum.com/t/amazon-product-api-hmac-signature/167650/3 "2009-08-10T10:54:46Z")
Hi Jonathan, Have you found some solution to this issue? I am using ruby/aws and I have received that my requests are not signed. I would appreciate any help to solve this problem. Thank you. Jonathan R. wrote: > So, starting August 15th, the Amazon product web service API (the one > where you can get info about amazon products, manipulate wishlists and > shopping carts, etc), is going to require a form of cryptographic > signature on all requests. > > [http://docs.amazonwebservices.com/AWSECommerceService/latest/DG/](http://docs.amazonwebservices.com/AWSECommerceService/latest/DG/) > > I think I can put everything together from various gems. But it’s kind > of picky (for instance, you have to make sure to CGI-escape in exactly > the right way and not over-escape at certain points). > > I’m wondering if anyone knows if anyone’s already tackled this, and > maybe has a gem with tests that’ll do it for you? Maybe part of some > larger amazon-interaction gem or something? This authentication method > has been used with other AWS apis for a while now I think. But I can’t > find anything. > > If not, and I write it, do you all think it would be a good thing to > distribute as a gem? It probably won’t be very many lines of code, but > making sure you’ve got the _right_ few lines of code that don’t have any > bugs in them is the trick. > > Thanks for any advice, > Jonathan ---
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [September 1, 2009, 4:17pm UTC](https://www.ruby-forum.com/t/amazon-product-api-hmac-signature/167650/4 "2009-09-01T16:17:33Z")
César Díaz wrote: > Hi Jonathan, > > Have you found some solution to this issue? [signing Amazon Product API requests]. > I am using ruby/aws and I > have received that my requests are not signed. I would appreciate any > help to solve this problem. Yes, I found and adapted some code from Chris R… See my version here: > **[Authenticating to Amazon Product API in ruby](https://bibwild.wordpress.com/2009/05/18/authenticating-to-amazon-product-api-in-ruby/)** > > So, the Amazon Product Advertising API (formerly known as Amazon E-Commerce API, formerly known as just Amazon Web Services back when it was the only one) will require a cryptographic signature on … I am not using ruby/aws, however. I guess ruby/aws needs to be updated to do signing; talk to the developer of that gem, or try to figure out how to do it yourself (perhaps guided by the code pointed to above). Or stop using ruby/aws and do it yourself manually using the code pointed to above. Jonathan