fix: allow S3 gateway passthrough for SSE-S3 header (#12020)

only in case of S3 gateway we have a case where we
need to allow for SSE-S3 headers as passthrough,

If SSE-C headers are passed then they are rejected
if KMS is not configured.

cmd/api-errors.go

@@ -381,6 +381,13 @@ func (e errorCodeMap) ToAPIErrWithErr(errCode APIErrorCode, err error) APIError
 	if err != nil {
 		apiErr.Description = fmt.Sprintf("%s (%s)", apiErr.Description, err)
 	}
+	if globalServerRegion != "" {
+		switch errCode {
+		case ErrAuthorizationHeaderMalformed:
+			apiErr.Description = fmt.Sprintf("The authorization header is malformed; the region is wrong; expecting '%s'.", globalServerRegion)
+			return apiErr
+		}
+	}
 	return apiErr
 }
 
@@ -2116,6 +2123,13 @@ func toAPIError(ctx context.Context, err error) APIError {
 				Description:    e.Message,
 				HTTPStatusCode: e.StatusCode,
 			}
+			if globalIsGateway && strings.Contains(e.Message, "KMS is not configured") {
+				apiErr = APIError{
+					Code:           "NotImplemented",
+					Description:    e.Message,
+					HTTPStatusCode: http.StatusNotImplemented,
+				}
+			}
 		case *googleapi.Error:
 			apiErr = APIError{
 				Code:           "XGCSInternalError",

cmd/object-handlers.go

@@ -876,6 +876,7 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
 		return
 	}
+
 	vars := mux.Vars(r)
 	dstBucket := vars["bucket"]
 	dstObject, err := unescapePath(vars["object"])
@@ -1395,10 +1396,19 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 		return
 	}
 
-	if _, ok := crypto.IsRequested(r.Header); !objectAPI.IsEncryptionSupported() && ok {
+	if _, ok := crypto.IsRequested(r.Header); ok {
+		if globalIsGateway {
+			if crypto.SSEC.IsRequested(r.Header) && !objectAPI.IsEncryptionSupported() {
 				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
 				return
 			}
+		} else {
+			if !objectAPI.IsEncryptionSupported() {
+				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
+				return
+			}
+		}
+	}
 
 	vars := mux.Vars(r)
 	bucket := vars["bucket"]
@@ -1698,10 +1708,19 @@ func (api objectAPIHandlers) PutObjectExtractHandler(w http.ResponseWriter, r *h
 		return
 	}
 
-	if _, ok := crypto.IsRequested(r.Header); !objectAPI.IsEncryptionSupported() && ok {
+	if _, ok := crypto.IsRequested(r.Header); ok {
+		if globalIsGateway {
+			if crypto.SSEC.IsRequested(r.Header) && !objectAPI.IsEncryptionSupported() {
 				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
 				return
 			}
+		} else {
+			if !objectAPI.IsEncryptionSupported() {
+				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
+				return
+			}
+		}
+	}
 
 	vars := mux.Vars(r)
 	bucket := vars["bucket"]
@@ -1978,10 +1997,19 @@ func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r
 		return
 	}
 
-	if _, ok := crypto.IsRequested(r.Header); !objectAPI.IsEncryptionSupported() && ok {
+	if _, ok := crypto.IsRequested(r.Header); ok {
+		if globalIsGateway {
+			if crypto.SSEC.IsRequested(r.Header) && !objectAPI.IsEncryptionSupported() {
 				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
 				return
 			}
+		} else {
+			if !objectAPI.IsEncryptionSupported() {
+				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
+				return
+			}
+		}
+	}
 
 	vars := mux.Vars(r)
 	bucket := vars["bucket"]
@@ -2429,10 +2457,20 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 		return
 	}
 
-	if _, ok := crypto.IsRequested(r.Header); !objectAPI.IsEncryptionSupported() && ok {
+	if _, ok := crypto.IsRequested(r.Header); ok {
+		if globalIsGateway {
+			if crypto.SSEC.IsRequested(r.Header) && !objectAPI.IsEncryptionSupported() {
 				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
 				return
 			}
+		} else {
+			if !objectAPI.IsEncryptionSupported() {
+				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL, guessIsBrowserReq(r))
+				return
+			}
+		}
+	}
+
 	vars := mux.Vars(r)
 	bucket := vars["bucket"]
 	object, err := unescapePath(vars["object"])

docs/gateway/s3.md

@@ -67,22 +67,28 @@ As a prerequisite to run MinIO S3 gateway on an AWS S3 compatible service, you n
 ## Run MinIO Gateway with double-encryption
 MinIO gateway to S3 supports encryption of data at rest. Three types of encryption modes are supported
 
-- encryption can be set to ``pass-through`` to backend
+- encryption can be set to ``pass-through`` to backend only for SSE-S3, SSE-C is not allowed passthrough.
 - ``single encryption`` (at the gateway)
-- ``double encryption`` (single encryption at gateway and pass through to backend).
+- ``double encryption`` (single encryption at gateway and pass through to backend)
 
 This can be specified by setting MINIO_GATEWAY_SSE environment variable. If MINIO_GATEWAY_SSE and KMS are not setup, all encryption headers are passed through to the backend. If KMS environment variables are set up, ``single encryption`` is automatically performed at the gateway and encrypted object is saved at the backend.
 
 To specify ``double encryption``, MINIO_GATEWAY_SSE environment variable needs to be set to "s3" for sse-s3
 and "c" for sse-c encryption. More than one encryption option can be set, delimited by ";". Objects are encrypted at the gateway and the gateway also does a pass-through to backend. Note that in the case of SSE-C encryption, gateway derives a unique SSE-C key for pass through from the SSE-C client key using a key derivation function (KDF).
 
+
+```sh
+curl -sSL --tlsv1.2 \
+     -O 'https://raw.githubusercontent.com/minio/kes/master/root.key' \
+     -O 'https://raw.githubusercontent.com/minio/kes/master/root.cert'
+```
+
 ```sh
 export MINIO_GATEWAY_SSE="s3;c"
-export MINIO_KMS_VAULT_APPROLE_ID=9b56cc08-8258-45d5-24a3-679876769126
+export MINIO_KMS_KES_ENDPOINT=https://play.min.io:7373
-export MINIO_KMS_VAULT_APPROLE_SECRET=4e30c52f-13e4-a6f5-0763-d50e8cb4321f
+export MINIO_KMS_KES_KEY_FILE=root.key
-export MINIO_KMS_VAULT_ENDPOINT=https://vault-endpoint-ip:8200
+export MINIO_KMS_KES_CERT_FILE=root.cert
-export MINIO_KMS_VAULT_KEY_NAME=my-minio-key
+export MINIO_KMS_KES_KEY_NAME=my-minio-key
-export MINIO_KMS_VAULT_AUTH_TYPE=approle
 minio gateway s3
 ```
 

pkg/net/url.go

@@ -186,6 +186,12 @@ func IsNetworkOrHostDown(err error, expectTimeouts bool) bool {
 	case strings.Contains(err.Error(), "connection timed out"):
 		// If err is a net.Dial timeout.
 		return true
+	case strings.Contains(err.Error(), "connection reset by peer"):
+		// IF err is a peer reset on a socket.
+		return true
+	case strings.Contains(err.Error(), "broken pipe"):
+		// IF err is a broken pipe on a socket.
+		return true
 	case strings.Contains(strings.ToLower(err.Error()), "503 service unavailable"):
 		// Denial errors
 		return true