dotnet/Documentation/compatibility/rsacng-now-correctly-loads-rsa-keys-of-non-standard-keysize.md

RSACng now correctly loads RSA keys of non-standard key size

Scope

Edge

Version Introduced

4.6.2

Source Analyzer Status

Planned

Change Description

In .NET Framework versions prior to 4.6.2, customers with non-standard key sizes for RSA certificates are unable to access those keys via the GetRSAPublicKey() and GetRSAPrivateKey() extension methods. A CryptographicException with the message "The requested key size is not supported" is thrown. In .NET Framework 4.6.2 this issue has been fixed. Similarly, RSA.ImportParameters() and RSACng.ImportParameters() now work with non-standard key sizes without throwing CryptographicException's.

• Quirked
• Build-time break

Recommended Action

If there is any exception handling logic that relies on the previous behavior where a CryptographicException is thrown when non-standard key sizes are used, consider removing the logic.

Affected APIs

• M:System.Security.Cryptography.RSA.ImportParameters(System.Security.Cryptography.RSAParameters)
• M:System.Security.Cryptography.RSACng.ImportParameters(System.Security.Cryptography.RSAParameters)
• M:System.Security.Cryptography.X509Certificates.RSACertificateExtensions.GetRSAPrivateKey(System.Security.Cryptography.X509Certificates.X509Certificate2)
• M:System.Security.Cryptography.X509Certificates.RSACertificateExtensions.GetRSAPublicKey(System.Security.Cryptography.X509Certificates.X509Certificate2)

Category

Security