Describe the bug
The class JwtDecoderProviderConfigurationUtils is instanciating the RestTemplate instead of using the bean, making impossible to customise the SSL context.
https://github.com/spring-projects/spring-security/blob/master/oauth2/oauth2-jose/src/main/java/org/springframework/security/oauth2/jwt/JwtDecoderProviderConfigurationUtils.java#L42
To Reproduce
Try to setup a sample project as an OAuth2 resource server pointing to an AS exposed with a self signed certificate for example. This would throw a SSLHandshakeException.
Expected behavior
Use the bean.
Comment From: jgrandja
Closing as duplicate of #8882. Please see JwtDecoders and provide any additional feedback there.