fix(s3): allow wildcard in imported buckets

packages/@aws-cdk/aws-s3/lib/bucket.ts

@@ -1540,7 +1540,7 @@ export class Bucket extends BucketBase {
     if (!bucketName) {
       throw new Error('Bucket name is required');
     }
-    Bucket.validateBucketName(bucketName);
+    Bucket.validateBucketName(bucketName, true);
 
     const newUrlFormat = attrs.bucketWebsiteNewUrlFormat === undefined
       ? false
@@ -1585,7 +1585,7 @@ export class Bucket extends BucketBase {
    *
    * @param physicalName name of the bucket.
    */
-  public static validateBucketName(physicalName: string): void {
+  public static validateBucketName(physicalName: string, allowWildcard: boolean = false): void {
     const bucketName = physicalName;
     if (!bucketName || Token.isUnresolved(bucketName)) {
       // the name is a late-bound value, not a defined string,
@@ -1596,19 +1596,20 @@ export class Bucket extends BucketBase {
     const errors: string[] = [];
 
     // Rules codified from https://docs.aws.amazon.com/AmazonS3/latest/dev/BucketRestrictions.html
-    if (bucketName.length < 3 || bucketName.length > 63) {
+    if ((!allowWildcard || bucketName.indexOf('*') === -1) && (bucketName.length < 3 || bucketName.length > 63)) {
       errors.push('Bucket name must be at least 3 and no more than 63 characters');
     }
-    const charsetMatch = bucketName.match(/[^a-z0-9.-]/);
+    const charsetMatch = bucketName.match(/[^*a-z0-9.-]/);
     if (charsetMatch) {
       errors.push('Bucket name must only contain lowercase characters and the symbols, period (.) and dash (-) '
         + `(offset: ${charsetMatch.index})`);
     }
-    if (!/[a-z0-9]/.test(bucketName.charAt(0))) {
+    const allowedCharsStartEnd = allowWildcard ? /[*a-z0-9]/ : /[a-z0-9]/;
+    if (!allowedCharsStartEnd.test(bucketName.charAt(0))) {
       errors.push('Bucket name must start and end with a lowercase character or number '
         + '(offset: 0)');
     }
-    if (!/[a-z0-9]/.test(bucketName.charAt(bucketName.length - 1))) {
+    if (!allowedCharsStartEnd.test(bucketName.charAt(bucketName.length - 1))) {
       errors.push('Bucket name must start and end with a lowercase character or number '
         + `(offset: ${bucketName.length - 1})`);
     }

packages/@aws-cdk/aws-s3/test/bucket.test.ts

@@ -715,6 +715,34 @@ describe('bucket', () => {
     });
   });
 
+  test('import allows short bucket name with wild card', () => {
+    const stack = new cdk.Stack(undefined, undefined, {
+      env: { region: 'us-east-1' },
+    });
+
+    const bucket = s3.Bucket.fromBucketAttributes(stack, 'ImportedBucket', {
+      bucketName: 'm*',
+    });
+
+    expect(stack.resolve(bucket.bucketArn)).toEqual({
+      'Fn::Join': ['', ['arn:', { Ref: 'AWS::Partition' }, ':s3:::m*']],
+    });
+  });
+
+  test('import allows bucket name with wild card', () => {
+    const stack = new cdk.Stack(undefined, undefined, {
+      env: { region: 'us-east-1' },
+    });
+
+    const bucket = s3.Bucket.fromBucketAttributes(stack, 'ImportedBucket', {
+      bucketName: 'my-bucket*',
+    });
+
+    expect(stack.resolve(bucket.bucketArn)).toEqual({
+      'Fn::Join': ['', ['arn:', { Ref: 'AWS::Partition' }, ':s3:::my-bucket*']],
+    });
+  });
+
   test('grantRead', () => {
     const stack = new cdk.Stack();
     const reader = new iam.User(stack, 'Reader');