Azure API Management | SHA 256

Question

Hi

I want to hash in SHA256 in Azure APIM

Answer 1

Hi Abhay Chandramouli

Thanks for reaching out on Microsoft Q&A!

The following code snippet allows you to SHA256 hash a string in the Azure API Management policy, where you can replace <signing-key> with your own signing key, and <string-to-sign> with the value you want to hash:

  @{  
       System.Security.Cryptography.HMACSHA256 hasher = new System.Security.Cryptography.HMACSHA256(<signing-key>);  
       return Convert.ToBase64String(hasher.ComputeHash(System.Text.Encoding.UTF8.GetBytes(<string-to-sign>)));  
   }  

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Feel free to drop additional queries in the comments below!

Kind regards,

Sonny

Answer 2

Hi @Sonny Gillissen Is there any way to set the calculated Hash in an APIM variable using set-variable policy, I am trying to compare the hash sent by front end and calculated by APIM.

or is there any way to create the hash and compare the same with the one sent in header of the request.

Whenever I a m trying to set value using set-variable APIM policy I am getting error "cannot convert from 'string' to 'byte[]'". I tried methods given here to convert byte array to string but Its always giving the same error.

Best regards,

Abhishek