EncryptedXml uses obsolete Rijndael* types

[ViktorHofer]

C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(549,17): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(549,44): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(598,32): error SYSLIB0022: 'Rijndael' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(624,13): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(624,40): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(871,44): error SYSLIB0022: 'Rijndael' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(915,44): error SYSLIB0022: 'Rijndael' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]

runtime/src/libraries/System.Security.Cryptography.Xml/src/System.Security.Cryptography.Xml.csproj

Lines 9 to 10 in 9d771a2

	<!-- RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead. https://github.com/dotnet/runtime/issues/54145. -->
	<NoWarn Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETCoreApp'">$(NoWarn);SYSLIB0022</NoWarn>

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Issue Details

---

C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(549,17): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(549,44): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(598,32): error SYSLIB0022: 'Rijndael' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(624,13): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(624,40): error SYSLIB0022: 'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(871,44): error SYSLIB0022: 'Rijndael' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]
C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System\Security\Cryptography\Xml\EncryptedXml.cs(915,44): error SYSLIB0022: 'Rijndael' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' [C:\git\runtime2\src\libraries\System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj]

cc @bartonjs @GrabYourPitchforks

Author:	ViktorHofer
Assignees:	-
Labels:	area-System.Security
Milestone:	-

[vcsjones]

Just for my own understanding, how did you trigger these build errors? Why didn't these appear during CI, or when I build locally?

[ViktorHofer]

Ah forgot to mention that. That error appears when adding a net6.0 tfm to the project.

[ViktorHofer]

@vcsjones would you like to take a stab on resolving the warnings? The changes are now in main.

[vcsjones]

A question for @bartonjs though... do we want to fix the Rijndael usages in S.S.Cryptography.Xml or are we happy with the NoWarn for SYSLIB0022? My understanding is that this package is trying to churn as little as possible.

[bartonjs]

Since new RijndaelManaged() just returns an object shimming into an object returned from Aes.Create() we can probably just replace the usage and make the warnings go away.