From 3e928bcad6552bc09d4542859180701ca508a524 Mon Sep 17 00:00:00 2001
From: Ben Simon Hartung <42031100+bentsku@users.noreply.github.com>
Date: Thu, 7 Sep 2023 09:20:24 +0200
Subject: [PATCH] S3: fix Range request handling (#6778)

---
 moto/s3/responses.py     | 28 +++++++++++++++++--------
 tests/test_s3/test_s3.py | 45 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index 701400b72..1510ce112 100644
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -1169,25 +1169,35 @@ class S3Response(BaseResponse):
     ) -> TYPE_RESPONSE:
         length = len(response_content)
         last = length - 1
+
         _, rspec = request.headers.get("range").split("=")
         if "," in rspec:
-            raise NotImplementedError("Multiple range specifiers not supported")
+            return 200, response_headers, response_content
 
-        def toint(i: Any) -> Optional[int]:
-            return int(i) if i else None
+        try:
+            begin, end = [int(i) if i else None for i in rspec.split("-")]
+        except ValueError:
+            # if we can't parse the Range header, S3 just treat the request as a non-range request
+            return 200, response_headers, response_content
+
+        if (begin is None and end == 0) or (begin is not None and begin > last):
+            raise InvalidRange(
+                actual_size=str(length), range_requested=request.headers.get("range")
+            )
 
-        begin, end = map(toint, rspec.split("-"))
         if begin is not None:  # byte range
             end = last if end is None else min(end, last)
         elif end is not None:  # suffix byte range
             begin = length - min(end, length)
             end = last
         else:
-            return 400, response_headers, ""
-        if begin < 0 or end > last or begin > min(end, last):
-            raise InvalidRange(
-                actual_size=str(length), range_requested=request.headers.get("range")
-            )
+            # Treat as non-range request
+            return 200, response_headers, response_content
+
+        if begin > min(end, last):
+            # Treat as non-range request if after the logic is applied, the start of the range is greater than the end
+            return 200, response_headers, response_content
+
         response_headers["content-range"] = f"bytes {begin}-{end}/{length}"
         content = response_content[begin : end + 1]
         response_headers["content-length"] = len(content)
diff --git a/tests/test_s3/test_s3.py b/tests/test_s3/test_s3.py
index 962ea8602..766f14de1 100644
--- a/tests/test_s3/test_s3.py
+++ b/tests/test_s3/test_s3.py
@@ -1004,6 +1004,51 @@ def test_ranged_get():
 
     assert key.content_length == 100
 
+    assert key.get(Range="bytes=0-0")["Body"].read() == b"0"
+    assert key.get(Range="bytes=1-1")["Body"].read() == b"1"
+
+    range_req = key.get(Range="bytes=1-0")
+    assert range_req["Body"].read() == rep * 10
+    # assert that the request was not treated as a range request
+    assert range_req["ResponseMetadata"]["HTTPStatusCode"] == 200
+    assert "ContentRange" not in range_req
+
+    range_req = key.get(Range="bytes=-1-")
+    assert range_req["Body"].read() == rep * 10
+    assert range_req["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    range_req = key.get(Range="bytes=0--1")
+    assert range_req["Body"].read() == rep * 10
+    assert range_req["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    range_req = key.get(Range="bytes=0-1,3-4,7-9")
+    assert range_req["Body"].read() == rep * 10
+    assert range_req["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    range_req = key.get(Range="bytes=-")
+    assert range_req["Body"].read() == rep * 10
+    assert range_req["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    with pytest.raises(ClientError) as ex:
+        key.get(Range="bytes=-0")
+    assert ex.value.response["Error"]["Code"] == "InvalidRange"
+    assert (
+        ex.value.response["Error"]["Message"]
+        == "The requested range is not satisfiable"
+    )
+    assert ex.value.response["Error"]["ActualObjectSize"] == "100"
+    assert ex.value.response["Error"]["RangeRequested"] == "bytes=-0"
+
+    with pytest.raises(ClientError) as ex:
+        key.get(Range="bytes=101-200")
+    assert ex.value.response["Error"]["Code"] == "InvalidRange"
+    assert (
+        ex.value.response["Error"]["Message"]
+        == "The requested range is not satisfiable"
+    )
+    assert ex.value.response["Error"]["ActualObjectSize"] == "100"
+    assert ex.value.response["Error"]["RangeRequested"] == "bytes=101-200"
+
 
 @mock_s3
 def test_policy():