CngKey System.Security.Cryptography.CryptographicException The system cannot find the file specified on Azure

Question

I try to generate key from this code

CngKey key = CngKey.Import(Convert.FromBase64String(privateKey), CngKeyBlobFormat.Pkcs8PrivateBlob);

it works fine locally but when I deploy in my Azure app service. it gives me this error:

System.Security.Cryptography.CryptographicException: The system cannot find the file specified. at System.Security.Cryptography.NCryptNative.ImportKey(SafeNCryptProviderHandle provider, Byte[] keyBlob, String format) at System.Security.Cryptography.CngKey.Import(Byte[] keyBlob, String curveName, CngKeyBlobFormat format, CngProvider provider)

I add WEBSITE_LOAD_USER_PROFILE In Configuration with value '1' but it didn't make any difference.

Thanks

Answer 1

I upgraded the plan service from free to basic with adding WEBSITE_LOAD_USER_PROFILE = 1 in Azure Configuration.

The issue was when the app service was free it use a shared VM but when upgrading my app service pricing into basic it use a private VM.

Answer 2

If WEBSITE_LOAD_USER_PROFILE = 1 does not work for you. Here is a workaround for this same issue:

• Open your Azure App Service (Azure Website) blade in portal.azure.com
• Go to the Application settings page
• Scroll to App settings
• Add a new entry key: WEBSITE_LOAD_CERTIFICATES, and provide a dummy (fake, made-up, randomly-generated) value for it.

Check out the below links for the similar issue for reference:

• X509Certificate2 on Azure App Services (Azure Websites) since mid-2017?
• GH issue #16