fix: reject unsupported checksum assertions

Reject unimplemented x-amz-checksum value and trailer names instead of accepting uploads without verification. Apply the same contract to PutObject, multipart initiation and parts, CopyObject, and UploadPartCopy while preserving the five supported algorithms.

Signed-off-by: Feng Ruohang <rh@vonng.com>

cmd/object-api-options.go

@@ -439,6 +439,9 @@ func putOptsFromHeaders(ctx context.Context, hdr http.Header, metadata map[strin
 
 // get ObjectOptions for Copy calls with encryption headers provided on the target side and source side metadata
 func copyDstOpts(ctx context.Context, r *http.Request, bucket, object string, metadata map[string]string) (opts ObjectOptions, err error) {
+	if _, err := hash.GetContentChecksum(r.Header); err != nil {
+		return opts, err
+	}
 	return putOptsFromReq(ctx, r, bucket, object, metadata)
 }
 

cmd/object-checksum-unsupported_test.go

@@ -0,0 +1,137 @@
+// Copyright (c) 2015-2026 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/xml"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/minio/minio/internal/auth"
+	xhttp "github.com/minio/minio/internal/http"
+)
+
+func TestAPIRejectsUnsupportedChecksumHeaders(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testAPIRejectsUnsupportedChecksumHeaders,
+		endpoints:  []string{"CopyObject", "NewMultipart", "PutObject", "PutObjectPart"},
+	})
+}
+
+func testAPIRejectsUnsupportedChecksumHeaders(obj ObjectLayer, instanceType, bucketName string,
+	apiRouter http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	data := []byte("unsupported-checksum")
+	unsupportedValue := base64.StdEncoding.EncodeToString(make([]byte, 64))
+
+	put := func(object string, headers map[string]string) *httptest.ResponseRecorder {
+		t.Helper()
+		req, err := newTestSignedRequestV4(http.MethodPut, getPutObjectURL("", bucketName, object),
+			int64(len(data)), bytes.NewReader(data), credentials.AccessKey, credentials.SecretKey, headers)
+		if err != nil {
+			t.Fatal(err)
+		}
+		rec := httptest.NewRecorder()
+		apiRouter.ServeHTTP(rec, req)
+		return rec
+	}
+	assertRejected := func(name string, rec *httptest.ResponseRecorder) {
+		t.Helper()
+		if rec.Code != http.StatusBadRequest || !strings.Contains(rec.Body.String(), "<Code>InvalidArgument</Code>") {
+			t.Fatalf("%s: %s returned %d, want InvalidArgument: %s", instanceType, name, rec.Code, rec.Body.String())
+		}
+	}
+
+	for _, algorithm := range []string{"md5", "sha512", "xxhash64", "xxhash3", "xxhash128", "future"} {
+		object := "checksums/unsupported-" + algorithm
+		assertRejected(algorithm, put(object, map[string]string{
+			"x-amz-sdk-checksum-algorithm": "SHA512",
+			"x-amz-checksum-" + algorithm:  unsupportedValue,
+		}))
+		if _, err := obj.GetObjectInfo(t.Context(), bucketName, object, ObjectOptions{}); !isErrObjectNotFound(err) {
+			t.Fatalf("%s: rejected %s checksum stored an object: %v", instanceType, algorithm, err)
+		}
+	}
+
+	assertRejected("unsupported trailer", put("checksums/unsupported-trailer", map[string]string{
+		xhttp.AmzTrailer: "x-amz-checksum-sha512",
+	}))
+
+	newMultipart := func(name string, headers map[string]string) *httptest.ResponseRecorder {
+		t.Helper()
+		req, err := newTestSignedRequestV4(http.MethodPost, getNewMultipartURL("", bucketName, name),
+			0, nil, credentials.AccessKey, credentials.SecretKey, headers)
+		if err != nil {
+			t.Fatal(err)
+		}
+		rec := httptest.NewRecorder()
+		apiRouter.ServeHTTP(rec, req)
+		return rec
+	}
+	assertRejected("NewMultipartUpload value header", newMultipart("checksums/mp-value", map[string]string{
+		"x-amz-checksum-sha512": unsupportedValue,
+	}))
+	assertRejected("NewMultipartUpload trailer", newMultipart("checksums/mp-trailer", map[string]string{
+		xhttp.AmzTrailer: "x-amz-checksum-sha512",
+	}))
+
+	rec := newMultipart("checksums/mp-part", nil)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("%s: NewMultipartUpload setup returned %d: %s", instanceType, rec.Code, rec.Body.String())
+	}
+	var initiated InitiateMultipartUploadResponse
+	if err := xml.Unmarshal(rec.Body.Bytes(), &initiated); err != nil {
+		t.Fatal(err)
+	}
+	req, err := newTestSignedRequestV4(http.MethodPut,
+		getPutObjectPartURL("", bucketName, "checksums/mp-part", initiated.UploadID, "1"),
+		int64(len(data)), bytes.NewReader(data), credentials.AccessKey, credentials.SecretKey,
+		map[string]string{"x-amz-checksum-sha512": unsupportedValue})
+	if err != nil {
+		t.Fatal(err)
+	}
+	rec = httptest.NewRecorder()
+	apiRouter.ServeHTTP(rec, req)
+	assertRejected("UploadPart", rec)
+	parts, err := obj.ListObjectParts(t.Context(), bucketName, "checksums/mp-part", initiated.UploadID, 0, 1000, ObjectOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(parts.Parts) != 0 {
+		t.Fatalf("%s: rejected UploadPart stored %d parts", instanceType, len(parts.Parts))
+	}
+	if err := obj.AbortMultipartUpload(t.Context(), bucketName, "checksums/mp-part", initiated.UploadID, ObjectOptions{}); err != nil {
+		t.Fatal(err)
+	}
+
+	source := "checksums/source"
+	putCopyChecksumSource(t, apiRouter, credentials, bucketName, source, data, nil)
+	rec = copyChecksumRequest(t, apiRouter, credentials, bucketName, source, "checksums/copy", map[string]string{
+		"x-amz-checksum-sha512": unsupportedValue,
+	})
+	assertRejected("CopyObject", rec)
+	if _, err := obj.GetObjectInfo(t.Context(), bucketName, "checksums/copy", ObjectOptions{}); !isErrObjectNotFound(err) {
+		t.Fatalf("%s: rejected CopyObject stored a destination: %v", instanceType, err)
+	}
+}

cmd/object-multipart-handlers.go

@@ -309,6 +309,10 @@ func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r
 		}
 	}
 
+	if _, err := hash.GetContentChecksum(r.Header); err != nil {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidChecksum), r.URL)
+		return
+	}
 	checksumType := hash.NewChecksumHeader(r.Header)
 	if checksumType.Is(hash.ChecksumInvalid) {
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidChecksum), r.URL)

internal/hash/checksum.go

@@ -657,13 +657,42 @@ func AddChecksumHeader(w http.ResponseWriter, c map[string]string) {
 	}
 }
 
+func isSupportedChecksumHeader(name string) bool {
+	switch {
+	case strings.EqualFold(name, xhttp.AmzChecksumAlgo),
+		strings.EqualFold(name, xhttp.AmzChecksumType),
+		strings.EqualFold(name, xhttp.AmzChecksumMode):
+		return true
+	}
+	for _, checksumType := range BaseChecksumTypes {
+		if strings.EqualFold(name, checksumType.Key()) {
+			return true
+		}
+	}
+	return false
+}
+
+func hasUnsupportedChecksumHeader(h http.Header) bool {
+	for name := range h {
+		if strings.HasPrefix(strings.ToLower(name), "x-amz-checksum-") && !isSupportedChecksumHeader(name) {
+			return true
+		}
+	}
+	return false
+}
+
 // GetContentChecksum returns content checksum.
 // Returns ErrInvalidChecksum if so.
 // Returns nil, nil if no checksum.
 func GetContentChecksum(h http.Header) (*Checksum, error) {
+	if hasUnsupportedChecksumHeader(h) {
+		return nil, ErrInvalidChecksum
+	}
 	if trailing := h.Values(xhttp.AmzTrailer); len(trailing) > 0 {
 		var res *Checksum
-		for _, header := range trailing {
+		for _, headers := range trailing {
+			for header := range strings.SplitSeq(headers, ",") {
+				header = strings.TrimSpace(header)
 				var duplicates bool
 				for _, t := range BaseChecksumTypes {
 					if strings.EqualFold(t.Key(), header) {
@@ -671,10 +700,14 @@ func GetContentChecksum(h http.Header) (*Checksum, error) {
 						res = NewChecksumWithType(t|ChecksumTrailing, "")
 					}
 				}
+				if strings.HasPrefix(strings.ToLower(header), "x-amz-checksum-") && !isSupportedChecksumHeader(header) {
+					return nil, ErrInvalidChecksum
+				}
 				if duplicates {
 					return nil, ErrInvalidChecksum
 				}
 			}
+		}
 		if res != nil {
 			switch h.Get(xhttp.AmzChecksumType) {
 			case xhttp.AmzChecksumTypeFullObject:

internal/hash/checksum_test.go

@@ -18,12 +18,53 @@
 package hash
 
 import (
+	"errors"
+	"net/http"
 	"net/http/httptest"
 	"testing"
 
 	xhttp "github.com/minio/minio/internal/http"
 )
 
+func TestGetContentChecksumRejectsUnsupportedHeaders(t *testing.T) {
+	unsupported := []string{
+		"x-amz-checksum-md5",
+		"x-amz-checksum-sha512",
+		"x-amz-checksum-xxhash64",
+		"x-amz-checksum-xxhash3",
+		"x-amz-checksum-xxhash128",
+		"x-amz-checksum-future",
+	}
+	for _, header := range unsupported {
+		t.Run("header/"+header, func(t *testing.T) {
+			h := http.Header{header: {"AA=="}}
+			if _, err := GetContentChecksum(h); !errors.Is(err, ErrInvalidChecksum) {
+				t.Fatalf("GetContentChecksum(%s) error = %v, want ErrInvalidChecksum", header, err)
+			}
+		})
+		t.Run("trailer/"+header, func(t *testing.T) {
+			h := http.Header{xhttp.AmzTrailer: {header}}
+			if _, err := GetContentChecksum(h); !errors.Is(err, ErrInvalidChecksum) {
+				t.Fatalf("GetContentChecksum(trailer %s) error = %v, want ErrInvalidChecksum", header, err)
+			}
+		})
+	}
+
+	for header, value := range map[string]string{
+		xhttp.AmzChecksumAlgo:          "CRC32",
+		xhttp.AmzChecksumType:          xhttp.AmzChecksumTypeComposite,
+		xhttp.AmzChecksumMode:          "ENABLED",
+		"x-amz-sdk-checksum-algorithm": "SHA512",
+	} {
+		t.Run("control/"+header, func(t *testing.T) {
+			h := http.Header{header: {value}}
+			if _, err := GetContentChecksum(h); errors.Is(err, ErrInvalidChecksum) {
+				t.Fatalf("control header %s was rejected", header)
+			}
+		})
+	}
+}
+
 // TestChecksumAddToHeader tests that adding and retrieving a checksum on a header works
 func TestChecksumAddToHeader(t *testing.T) {
 	tests := []struct {