Replace Streams with Loops

First version of replacing streams

fix wwwAuthenticate and codestyle

fix errors in implementation to pass tests

Fix review notes

Remove uneccessary final to align with cb

Short circuit way to authorize

Simplify error message, make code readably

Return error while duplicate key found

Delete check for duplicate, checkstyle issues

Return duplicate error

Fixes gh-7154

core/src/main/java/org/springframework/security/authorization/AuthorityReactiveAuthorizationManager.java

@@ -22,7 +22,6 @@ import reactor.core.publisher.Mono;
 
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Stream;
 
 /**
  * A {@link ReactiveAuthorizationManager} that determines if the current user is
@@ -109,9 +108,14 @@ public class AuthorityReactiveAuthorizationManager<T> implements ReactiveAuthori
 			Assert.notNull(role, "role cannot be null");
 		}
 
-		return hasAnyAuthority(Stream.of(roles)
-				.map(r -> "ROLE_" + r)
-				.toArray(String[]::new)
-		);
+		return hasAnyAuthority(toNamedRolesArray(roles));
+	}
+
+	private static String[] toNamedRolesArray(String... roles) {
+		String[] result = new String[roles.length];
+		for (int i=0; i < roles.length; i++) {
+			result[i] = "ROLE_" + roles[i];
+		}
+		return result;
 	}
 }

core/src/main/java/org/springframework/security/converter/RsaKeyConverters.java

@@ -16,8 +16,8 @@
 
 package org.springframework.security.converter;
 
-import java.io.BufferedReader;
 import java.io.InputStream;
+import java.io.BufferedReader;
 import java.io.InputStreamReader;
 import java.security.KeyFactory;
 import java.security.NoSuchAlgorithmException;
@@ -25,8 +25,8 @@ import java.security.interfaces.RSAPrivateKey;
 import java.security.interfaces.RSAPublicKey;
 import java.security.spec.PKCS8EncodedKeySpec;
 import java.security.spec.X509EncodedKeySpec;
-import java.util.Base64;
 import java.util.List;
+import java.util.Base64;
 import java.util.stream.Collectors;
 
 import org.springframework.core.convert.converter.Converter;
@@ -66,10 +66,13 @@ public class RsaKeyConverters {
 			Assert.isTrue(!lines.isEmpty() && lines.get(0).startsWith(PKCS8_PEM_HEADER),
 					"Key is not in PEM-encoded PKCS#8 format, " +
 							"please check that the header begins with -----" + PKCS8_PEM_HEADER + "-----");
-			String base64Encoded = lines.stream()
-					.filter(RsaKeyConverters::isNotPkcs8Wrapper)
-					.collect(Collectors.joining());
-			byte[] pkcs8 = Base64.getDecoder().decode(base64Encoded);
+			StringBuilder base64Encoded = new StringBuilder();
+			for (String line : lines) {
+				if (RsaKeyConverters.isNotPkcs8Wrapper(line)) {
+					base64Encoded.append(line);
+				}
+			}
+			byte[] pkcs8 = Base64.getDecoder().decode(base64Encoded.toString());
 
 			try {
 				return (RSAPrivateKey) keyFactory.generatePrivate(
@@ -97,10 +100,13 @@ public class RsaKeyConverters {
 			Assert.isTrue(!lines.isEmpty() && lines.get(0).startsWith(X509_PEM_HEADER),
 					"Key is not in PEM-encoded X.509 format, " +
 							"please check that the header begins with -----" + X509_PEM_HEADER + "-----");
-			String base64Encoded = lines.stream()
-					.filter(RsaKeyConverters::isNotX509Wrapper)
-					.collect(Collectors.joining());
-			byte[] x509 = Base64.getDecoder().decode(base64Encoded);
+			StringBuilder base64Encoded = new StringBuilder();
+			for (String line : lines) {
+				if (RsaKeyConverters.isNotX509Wrapper(line)) {
+					base64Encoded.append(line);
+				}
+			}
+			byte[] x509 = Base64.getDecoder().decode(base64Encoded.toString());
 
 			try {
 				return (RSAPublicKey) keyFactory.generatePublic(

core/src/main/java/org/springframework/security/core/userdetails/MapReactiveUserDetailsService.java

@@ -19,8 +19,7 @@ package org.springframework.security.core.userdetails;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Map;
-import java.util.function.Function;
-import java.util.stream.Collectors;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.springframework.util.Assert;
 import reactor.core.publisher.Mono;
@@ -56,7 +55,10 @@ public class MapReactiveUserDetailsService implements ReactiveUserDetailsService
 	 */
 	public MapReactiveUserDetailsService(Collection<UserDetails> users) {
 		Assert.notEmpty(users, "users cannot be null or empty");
-		this.users = users.stream().collect(Collectors.toConcurrentMap( u -> getKey(u.getUsername()), Function.identity()));
+		this.users = new ConcurrentHashMap<>();
+		for (UserDetails user : users) {
+			this.users.put(getKey(user.getUsername()), user);
+		}
 	}
 
 	@Override

core/src/test/java/org/springframework/security/core/userdetails/MapReactiveUserDetailsServiceTests.java

@@ -46,6 +46,13 @@ public class MapReactiveUserDetailsServiceTests {
 		new MapReactiveUserDetailsService(users);
 	}
 
+	@Test
+	public void constructorCaseIntensiveKey() {
+		UserDetails userDetails = User.withUsername("USER").password("password").roles("USER").build();
+		MapReactiveUserDetailsService userDetailsService = new MapReactiveUserDetailsService(userDetails);
+		assertThat(userDetailsService.findByUsername("user").block()).isEqualTo(userDetails);
+	}
+
 	@Test
 	public void findByUsernameWhenFoundThenReturns() {
 		assertThat((users.findByUsername(USER_DETAILS.getUsername()).block())).isEqualTo(USER_DETAILS);