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/* * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. * A copy of the License is located at * * http://aws.amazon.com/apache2.0 * * or in the "license" file accompanying this file. This file is distributed * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either * express or implied. See the License for the specific language governing * permissions and limitations under the License. */ package com.amazonaws.services.s3.internal; import java.util.regex.Pattern; /** * Utilities for working with Amazon S3 bucket names, such as validation and * checked to see if they are compatible with DNS addressing. */ public enum BucketNameUtils { ; private static final int MIN_BUCKET_NAME_LENGTH = 3; private static final int MAX_BUCKET_NAME_LENGTH = 63; private static final Pattern ipAddressPattern = Pattern.compile("(\\d+\\.){3}\\d+"); /** * Validates that the specified bucket name is valid for Amazon S3 V2 naming * (i.e. DNS addressable in virtual host style). Throws an * IllegalArgumentException if the bucket name is not valid. * <p> * S3 bucket naming guidelines are specified in <a href="http://docs.amazonwebservices.com/AmazonS3/latest/dev/index.html?BucketRestrictions.html" * > http://docs.amazonwebservices.com/AmazonS3/latest/dev/index.html? * BucketRestrictions.html</a> * * @param bucketName * The bucket name to validate. * * @throws IllegalArgumentException * If the specified bucket name doesn't follow Amazon S3's * guidelines. */ public static void validateBucketName(final String bucketName) { isValidV2BucketName(bucketName, true); } /** * Returns true if the specified bucket name can be addressed using V2, * virtual host style, addressing. Otherwise, returns false indicating that * the bucket must be addressed using V1, path style, addressing. * * @param bucketName * The name of the bucket to check. * * @return True if the specified bucket name can be addressed in V2, virtual * host style, addressing otherwise false if V1, path style, * addressing is required. */ public static boolean isValidV2BucketName(String bucketName) { return isValidV2BucketName(bucketName, false); } /** * Convience method that allows the DNS rules to be altered for different SDKs. */ public static boolean isDNSBucketName(String bucketName) { return isValidV2BucketName(bucketName); } /** * Validate whether the given input is a valid bucket name. If throwOnError * is true, throw an IllegalArgumentException if validation fails. If * false, simply return 'false'. * * @param bucketName the name of the bucket * @param throwOnError true to throw exceptions on failure * @return true if the name is valid, false if not */ private static boolean isValidV2BucketName(final String bucketName, final boolean throwOnError) { if (bucketName == null) { return exception(throwOnError, "Bucket name cannot be null"); } if (bucketName.length() < MIN_BUCKET_NAME_LENGTH || bucketName.length() > MAX_BUCKET_NAME_LENGTH) { return exception(throwOnError, "Bucket name should be between " + MIN_BUCKET_NAME_LENGTH + " and " + MAX_BUCKET_NAME_LENGTH + " characters long"); } if (ipAddressPattern.matcher(bucketName).matches()) { return exception(throwOnError, "Bucket name must not be formatted as an IP Address"); } char previous = '\0'; for (int i = 0; i < bucketName.length(); ++i) { char next = bucketName.charAt(i); if (next >= 'A' && next <= 'Z') { return exception(throwOnError, "Bucket name should not contain uppercase characters"); } if (next == ' ' || next == '\t' || next == '\r' || next == '\n') { return exception(throwOnError, "Bucket name should not contain white space"); } if (next == '.') { if (previous == '\0') { return exception(throwOnError, "Bucket name should not begin with a period"); } if (previous == '.') { return exception(throwOnError, "Bucket name should not contain two adjacent periods"); } if (previous == '-') { return exception(throwOnError, "Bucket name should not contain dashes next to periods"); } } else if (next == '-') { if (previous == '.') { return exception(throwOnError, "Bucket name should not contain dashes next to periods"); } if (previous == '\0') { return exception(throwOnError, "Bucket name should not begin with a '-'"); } } else if ((next < '0') || (next > '9' && next < 'a') || (next > 'z')) { return exception(throwOnError, "Bucket name should not contain '" + next + "'"); } previous = next; } if (previous == '.' || previous == '-') { return exception(throwOnError, "Bucket name should not end with '-' or '.'"); } return true; } /** * If 'exception' is true, throw an IllegalArgumentException with the given * message. Otherwise, silently return false. * * @param exception true to throw an exception * @param message the message for the exception * @return false if 'exception' is false */ private static boolean exception(final boolean exception, final String message) { if (exception) { throw new IllegalArgumentException(message); } return false; } }