S3 PutObject with ChecksumAlgorithm Sets Empty Content-Encoding Header

[giacomorebecchi]

Describe the bug

When calling the method put_object in the S3 client, if the request has a ChecksumAlgorithm specified, the ContentEncoding argument gets overwritten and set to an empty string.

Expected Behavior

I expect my manually-set ContentEncoding argument to be preserved.

Current Behavior

Currently the ContentEncoding gets overwritten and set to an empty string.

Reproduction Steps

import boto3
import gzip

client = boto3.client("s3")
client.put_object(
    Body=gzip.compress(b"test-object"),
    Key="test/key",
    Bucket="test",
    ContentEncoding="gzip",  # I want this to be set to gzip
    ChecksumAlgorithm="SHA1",
)

client.head_object(
    Key="test/key",
    Bucket="test",
    ChecksumMode="ENABLED",
)

produces as output:

{'ResponseMetadata': {'RequestId': '...', 'HostId': '...', 'HTTPStatusCode': 200, 'HTTPHeaders': {'x-amz-id-2': '...', 'x-amz-request-id': '...', 'date': 'Thu, 26 Jan 2023 09:25:14 GMT', 'last-modified': 'Thu, 26 Jan 2023 09:25:13 GMT', 'etag': '"..."', 'x-amz-checksum-sha1': '/CTXfXUwTM/KvoFXC7OEpF7/dIA=', 'x-amz-server-side-encryption': 'AES256', 'content-encoding': '', 'accept-ranges': 'bytes', 'content-type': 'binary/octet-stream', 'server': 'AmazonS3', 'content-length': '25'}, 'RetryAttempts': 0}, 'AcceptRanges': 'bytes', 'LastModified': datetime.datetime(2023, 1, 26, 9, 25, 13, tzinfo=tzutc()), 'ContentLength': 25, 'ChecksumSHA1': '/CTXfXUwTM/KvoFXC7OEpF7/dIA=', 'ETag': '"75e79ae360a5e94d1c74a7ce1c80599c"', 'ContentEncoding': '', 'ContentType': 'binary/octet-stream', 'ServerSideEncryption': 'AES256', 'Metadata': {}}

Possible Solution

The same issue is being discussed in the Java SDK:

• S3 PutObject with ChecksumAlgorithm Sets Empty Content-Encoding Header aws/aws-sdk-java-v2#3569

Additional Information/Context

No response

SDK version used

1.26.57

Environment details (OS name and version, etc.)

Linux - Ubuntu

[tim-finnigan]

Thanks @giacomorebecchi for reaching out. I could reproduce the issue as you described. I'll mark this issue for further review by the team.

[nateprewitt]

Now that boto/botocore#2859 is merged, this should be resolved in today's release (boto3 1.26.62). We'll put this ticket on track to resolve in the next few days, but please let us know if you're still experiencing any issues with the latest release. Thanks!