Inline ResourceKeyConverterAdapter

Closes gh-9689
Closes gh-9626

config/src/main/java/org/springframework/security/config/crypto/RsaKeyConversionServicePostProcessor.java

@@ -18,6 +18,12 @@ package org.springframework.security.config.crypto;
 
 import java.beans.PropertyEditor;
 import java.beans.PropertyEditorSupport;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
+import java.security.Key;
 import java.security.interfaces.RSAPrivateKey;
 import java.security.interfaces.RSAPublicKey;
 
@@ -27,8 +33,9 @@ import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.converter.ConverterRegistry;
+import org.springframework.core.io.DefaultResourceLoader;
+import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
-import org.springframework.security.converter.ResourceKeyConverterAdapter;
 import org.springframework.security.converter.RsaKeyConverters;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -104,4 +111,66 @@ public class RsaKeyConversionServicePostProcessor implements BeanFactoryPostProc
 
 	}
 
+	static class ResourceKeyConverterAdapter<T extends Key> implements Converter<String, T> {
+
+		private ResourceLoader resourceLoader = new DefaultResourceLoader();
+
+		private final Converter<String, T> delegate;
+
+		/**
+		 * Construct a {@link ResourceKeyConverterAdapter} with the provided parameters
+		 * @param delegate converts a stream of key material into a {@link Key}
+		 */
+		ResourceKeyConverterAdapter(Converter<InputStream, T> delegate) {
+			this.delegate = pemInputStreamConverter().andThen(autoclose(delegate));
+		}
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public T convert(String source) {
+			return this.delegate.convert(source);
+		}
+
+		/**
+		 * Use this {@link ResourceLoader} to read the key material
+		 * @param resourceLoader the {@link ResourceLoader} to use
+		 */
+		void setResourceLoader(ResourceLoader resourceLoader) {
+			Assert.notNull(resourceLoader, "resourceLoader cannot be null");
+			this.resourceLoader = resourceLoader;
+		}
+
+		private Converter<String, InputStream> pemInputStreamConverter() {
+			return (source) -> source.startsWith("-----") ? toInputStream(source)
+					: toInputStream(this.resourceLoader.getResource(source));
+		}
+
+		private InputStream toInputStream(String raw) {
+			return new ByteArrayInputStream(raw.getBytes(StandardCharsets.UTF_8));
+		}
+
+		private InputStream toInputStream(Resource resource) {
+			try {
+				return resource.getInputStream();
+			}
+			catch (IOException ex) {
+				throw new UncheckedIOException(ex);
+			}
+		}
+
+		private <T> Converter<InputStream, T> autoclose(Converter<InputStream, T> inputStreamKeyConverter) {
+			return (inputStream) -> {
+				try (InputStream is = inputStream) {
+					return inputStreamKeyConverter.convert(is);
+				}
+				catch (IOException ex) {
+					throw new UncheckedIOException(ex);
+				}
+			};
+		}
+
+	}
+
 }