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IDX10720

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BrentSchmaltz edited this page Nov 30, 2023 · 12 revisions

IDX10720

If you receive the following exception such as: `"IDX10720: Unable to create KeyedHashAlgorithm for algorithm 'SHA256', the key size must be greater than: '256' bits, key has '128' bits. See https://aka.ms/IdentityModel/UnsafeRelaxHmacKeySizeValidation".

This means that you have specified to use HMAC256 as a crypto algorithm, but you have provided a key for this algorithm that is shorter than required. This means that you are less secure than you think!.

The numbers and name of the algorithm can vary. See: https://datatracker.ietf.org/doc/html/rfc7518#section-3.2 for details.

In Microsoft.IdentityModel 6.x we have fixed this security issue to ensure security is at the desired level. This ensures you conform with the specification.

If you receive this exception the best practice is to increase the size of your key with the suggested number of bits.

If you really cannot act immediately, you can set a feature flag to bypass this security check. We encourage you to address the root cause as soon as possible. To set this feature flag:



              


          



  
          

            

              

                

                  

                    
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