From 309d5eb3bc60eb46e8322a59b3f7a0f10ac841ce Mon Sep 17 00:00:00 2001
From: Bert Blommers <info@bertblommers.nl>
Date: Thu, 5 Oct 2023 07:43:53 +0000
Subject: [PATCH] S3: ContentLength-headers should be strings (#6884)

---
 moto/s3/responses.py               |  6 +++---
 tests/test_s3/test_s3_multipart.py | 32 ++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index d55f73381..89be2257e 100644
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -1190,7 +1190,7 @@ class S3Response(BaseResponse):
 
         response_headers["content-range"] = f"bytes {begin}-{end}/{length}"
         content = response_content[begin : end + 1]
-        response_headers["content-length"] = len(content)
+        response_headers["content-length"] = str(len(content))
         return 206, response_headers, content
 
     def _handle_v4_chunk_signatures(self, body: bytes, content_length: int) -> bytes:
@@ -1518,7 +1518,7 @@ class S3Response(BaseResponse):
                 )
                 response = ""
             response_headers.update(key.response_dict)
-            response_headers["content-length"] = len(response)
+            response_headers["content-length"] = str(len(response))
             return 200, response_headers, response
 
         storage_class = request.headers.get("x-amz-storage-class", "STANDARD")
@@ -1701,7 +1701,7 @@ class S3Response(BaseResponse):
             template = self.response_template(S3_OBJECT_COPY_RESPONSE)
             response_headers.update(new_key.response_dict)
             response = template.render(key=new_key)
-            response_headers["content-length"] = len(response)
+            response_headers["content-length"] = str(len(response))
             return 200, response_headers, response
 
         # Initial data
diff --git a/tests/test_s3/test_s3_multipart.py b/tests/test_s3/test_s3_multipart.py
index 0040c0c3a..b3925dff8 100644
--- a/tests/test_s3/test_s3_multipart.py
+++ b/tests/test_s3/test_s3_multipart.py
@@ -7,6 +7,7 @@ import boto3
 from botocore.client import ClientError
 import pytest
 import requests
+from unittest import SkipTest
 
 from moto import settings, mock_s3
 import moto.s3.models as s3model
@@ -1027,3 +1028,34 @@ def test_head_object_returns_part_count():
     # Header is not returned when we do not pass PartNumber
     resp = client.head_object(Bucket=bucket, Key=key)
     assert "PartsCount" not in resp
+
+
+@mock_s3
+@reduced_min_part_size
+def test_generate_presigned_url_for_multipart_upload():
+    if not settings.TEST_DECORATOR_MODE:
+        raise SkipTest("No point in testing this outside decorator mode")
+    bucket_name = "mock-bucket"
+    file_name = "mock-file"
+    s3_client = boto3.client("s3")
+    s3_client.create_bucket(Bucket=bucket_name)
+
+    mpu = s3_client.create_multipart_upload(
+        Bucket=bucket_name,
+        Key=file_name,
+    )
+    upload_id = mpu["UploadId"]
+
+    url = s3_client.generate_presigned_url(
+        "upload_part",
+        Params={
+            "Bucket": bucket_name,
+            "Key": file_name,
+            "PartNumber": 1,
+            "UploadId": upload_id,
+        },
+    )
+    data = b"0" * REDUCED_PART_SIZE
+
+    resp = requests.put(url, data=data)
+    assert resp.status_code == 200