Improve URI/query strings sanitization

spring-jdbc/src/main/java/org/springframework/jdbc/core/namedparam/NamedParameterUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -83,7 +83,7 @@ public abstract class NamedParameterUtils {
 		Assert.notNull(sql, "SQL must not be null");
 
 		Set<String> namedParameters = new HashSet<>();
-		String sqlToUse = sql;
+		StringBuilder sqlToUse = new StringBuilder(sql);
 		List<ParameterHolder> parameterList = new ArrayList<>();
 
 		char[] statement = sql.toCharArray();
@@ -155,7 +155,7 @@ public abstract class NamedParameterUtils {
 					int j = i + 1;
 					if (j < statement.length && statement[j] == ':') {
 						// escaped ":" should be skipped
-						sqlToUse = sqlToUse.substring(0, i - escapes) + sqlToUse.substring(i - escapes + 1);
+						sqlToUse.deleteCharAt(i - escapes);
 						escapes++;
 						i = i + 2;
 						continue;
@@ -174,7 +174,7 @@ public abstract class NamedParameterUtils {
 			}
 			i++;
 		}
-		ParsedSql parsedSql = new ParsedSql(sqlToUse);
+		ParsedSql parsedSql = new ParsedSql(sqlToUse.toString());
 		for (ParameterHolder ph : parameterList) {
 			parsedSql.addNamedParameter(ph.getParameterName(), ph.getStartIndex(), ph.getEndIndex());
 		}

spring-r2dbc/src/main/java/org/springframework/r2dbc/core/NamedParameterUtils.java

@@ -95,7 +95,7 @@ abstract class NamedParameterUtils {
 		Assert.notNull(sql, "SQL must not be null");
 
 		Set<String> namedParameters = new HashSet<>();
-		String sqlToUse = sql;
+		StringBuilder sqlToUse = new StringBuilder(sql);
 		List<ParameterHolder> parameterList = new ArrayList<>();
 
 		char[] statement = sql.toCharArray();
@@ -171,8 +171,7 @@ abstract class NamedParameterUtils {
 					int j = i + 1;
 					if (j < statement.length && statement[j] == ':') {
 						// escaped ":" should be skipped
-						sqlToUse = sqlToUse.substring(0, i - escapes)
-								+ sqlToUse.substring(i - escapes + 1);
+						sqlToUse.deleteCharAt(i - escapes);
 						escapes++;
 						i = i + 2;
 						continue;
@@ -181,7 +180,7 @@ abstract class NamedParameterUtils {
 			}
 			i++;
 		}
-		ParsedSql parsedSql = new ParsedSql(sqlToUse);
+		ParsedSql parsedSql = new ParsedSql(sqlToUse.toString());
 		for (ParameterHolder ph : parameterList) {
 			parsedSql.addNamedParameter(ph.getParameterName(), ph.getStartIndex(), ph.getEndIndex());
 		}

spring-web/src/main/java/org/springframework/web/util/UriComponentsBuilder.java

@@ -1023,15 +1023,21 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 			if (this.path.length() == 0) {
 				return null;
 			}
-			String path = this.path.toString();
-			while (true) {
-				int index = path.indexOf("//");
-				if (index == -1) {
-					break;
+			String sanitized = getSanitizedPath(this.path);
+			return new HierarchicalUriComponents.FullPathComponent(sanitized);
+		}
+
+		private static String getSanitizedPath(final StringBuilder path) {
+			int index = path.indexOf("//");
+			if (index >= 0) {
+				StringBuilder sanitized = new StringBuilder(path);
+				while (index != -1) {
+					sanitized.deleteCharAt(index);
+					index = sanitized.indexOf("//", index);
 				}
-				path = path.substring(0, index) + path.substring(index + 1);
+				return sanitized.toString();
 			}
-			return new HierarchicalUriComponents.FullPathComponent(path);
+			return path.toString();
 		}
 
 		public void removeTrailingSlash() {

spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java

@@ -401,18 +401,17 @@ public class UrlPathHelper {
 	 * <li>replace all "//" by "/"</li>
 	 * </ul>
 	 */
-	private String getSanitizedPath(final String path) {
-		String sanitized = path;
-		while (true) {
-			int index = sanitized.indexOf("//");
-			if (index < 0) {
-				break;
-			}
-			else {
-				sanitized = sanitized.substring(0, index) + sanitized.substring(index + 1);
+	private static String getSanitizedPath(final String path) {
+		int index = path.indexOf("//");
+		if (index >= 0) {
+			StringBuilder sanitized = new StringBuilder(path);
+			while (index != -1) {
+				sanitized.deleteCharAt(index);
+				index = sanitized.indexOf("//", index);
 			}
+			return sanitized.toString();
 		}
-		return sanitized;
+		return path;
 	}
 
 	/**
@@ -612,15 +611,20 @@ public class UrlPathHelper {
 				removeSemicolonContentInternal(requestUri) : removeJsessionid(requestUri));
 	}
 
-	private String removeSemicolonContentInternal(String requestUri) {
+	private static String removeSemicolonContentInternal(String requestUri) {
 		int semicolonIndex = requestUri.indexOf(';');
+		if (semicolonIndex == -1) {
+			return requestUri;
+		}
+		StringBuilder sb = new StringBuilder(requestUri);
 		while (semicolonIndex != -1) {
 			int slashIndex = requestUri.indexOf('/', semicolonIndex);
-			String start = requestUri.substring(0, semicolonIndex);
-			requestUri = (slashIndex != -1) ? start + requestUri.substring(slashIndex) : start;
-			semicolonIndex = requestUri.indexOf(';', semicolonIndex);
+			if (slashIndex >= 0) {
+				sb.delete(semicolonIndex, slashIndex);
+			}
+			semicolonIndex = sb.indexOf(";", semicolonIndex);
 		}
-		return requestUri;
+		return sb.toString();
 	}
 
 	private String removeJsessionid(String requestUri) {

spring-web/src/test/java/org/springframework/web/util/UriComponentsBuilderTests.java

@@ -1200,4 +1200,9 @@ class UriComponentsBuilderTests {
 		assertThat(UriComponentsBuilder.fromUriString("/path?q={asa}asa").toUriString()).isEqualTo("/path?q=%7Basa%7Dasa");
 	}
 
+	@Test
+	void verifyDoubleSlashReplacedWithSingleOne() {
+		String path = UriComponentsBuilder.fromPath("/home/").path("/path").build().getPath();
+		assertThat(path).isEqualTo("/home/path");
+	}
 }

spring-web/src/test/java/org/springframework/web/util/UrlPathHelperTests.java

@@ -104,6 +104,9 @@ public class UrlPathHelperTests {
 
 		request.setRequestURI("/foo+bar");
 		assertThat(helper.getRequestUri(request)).isEqualTo("/foo+bar");
+
+		request.setRequestURI("/home/" + "/path");
+		assertThat(helper.getRequestUri(request)).isEqualTo("/home/path");
 	}
 
 	@Test