Compat doc: GetECDsaPublicKey correctly handles brainpool curves (microsoft#1018)

krwq · Ron Petrusha · commit 3394bafc282a · 2019-04-29T12:07:07.000-07:00
* Create GetECDsaPublicKey-correctly-handles-brainpool-curves.md

* Update Documentation/compatibility/GetECDsaPublicKey-correctly-handles-brainpool-curves.md

Co-Authored-By: krwq &lt;mordotymoja@gmail.com&gt;

* Update Documentation/compatibility/GetECDsaPublicKey-correctly-handles-brainpool-curves.md

Co-Authored-By: krwq &lt;mordotymoja@gmail.com&gt;

* Update GetECDsaPublicKey-correctly-handles-brainpool-curves.md
diff --git a/Documentation/compatibility/GetECDsaPublicKey-correctly-handles-brainpool-curves.md b/Documentation/compatibility/GetECDsaPublicKey-correctly-handles-brainpool-curves.md
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+## ECDsaCertificateExtensions.GetECDsaPublicKey correctly handles Brainpool curves
+
+### Scope
+Edge case
+
+### Version Introduced
+4.8
+
+### Source Analyzer Status
+NotPlanned
+
+### Change Description
+Starting with .NET Framework 4.8, the <xref:System.Security.Cryptography.X509Certificates.ECDsaCertificateExtensions.GetECDsaPublicKey%2A?displayProperty=nameWithtype> method correctly handles all named curves supported by the OS, including the Brainpool elliptic curves.
+
+### Recommended Action
+If you encounter compatibility issues with this change on the .NET Framework 4.8 or a later version, you can opt-out of it by adding the following line to the \<runtime> section of the app.config file:
+
+```xml
+<appSettings>
+    <add key="Switch.System.Security.Cryptography.X509Certificates.ECDsaCertificateExtensions.UseLegacyPublicKeyReader" value="true" />
+</appSettings>
+```
+
+### Affected APIs
+
+* `M:System.Security.Cryptography.X509Certificates.ECDsaCertificateExtensions.GetECDsaPublicKey(System.Security.Cryptography.X509Certificates.X509Certificate2)`
+
+### Category
+Security
