github.com/zntrio/harp/v2@v2.0.9/pkg/sdk/ioutil/copy.go (about)

     1  // Licensed to Elasticsearch B.V. under one or more contributor
     2  // license agreements. See the NOTICE file distributed with
     3  // this work for additional information regarding copyright
     4  // ownership. Elasticsearch B.V. licenses this file to you under
     5  // the Apache License, Version 2.0 (the "License"); you may
     6  // not use this file except in compliance with the License.
     7  // You may obtain a copy of the License at
     8  //
     9  //     http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing,
    12  // software distributed under the License is distributed on an
    13  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    14  // KIND, either express or implied.  See the License for the
    15  // specific language governing permissions and limitations
    16  // under the License.
    17  
    18  package ioutil
    19  
    20  import (
    21  	"errors"
    22  	"io"
    23  )
    24  
    25  // ErrTruncatedCopy is raised when the copy is larger than expected.
    26  var ErrTruncatedCopy = errors.New("truncated copy due to too large input")
    27  
    28  // Copy uses a buffered CopyN and a hardlimit to stop read from the reader when
    29  // the maxSize amount of data has been written to the given writer.
    30  func Copy(maxSize int64, w io.Writer, r io.Reader) error {
    31  	contentLength := int64(0)
    32  
    33  	// Chunked read with hard limit to prevent/reduce zipbomb vulnerability
    34  	// exploitation.
    35  	for {
    36  		written, err := io.CopyN(w, r, 1024)
    37  		if err != nil {
    38  			if errors.Is(err, io.EOF) {
    39  				break
    40  			}
    41  			return err
    42  		}
    43  
    44  		// Add to length
    45  		contentLength += written
    46  
    47  		// Check max size
    48  		if contentLength > maxSize {
    49  			return ErrTruncatedCopy
    50  		}
    51  	}
    52  
    53  	// No error
    54  	return nil
    55  }