package api import ( "bytes" "context" "encoding/xml" "fmt" "net/http" "net/url" "strconv" "github.com/google/uuid" "github.com/minio/minio/misc" ) type ( // APIErrorResponse - error response format ErrorResponse struct { XMLName xml.Name `xml:"Error" json:"-"` Code string Message string Key string `xml:"Key,omitempty" json:"Key,omitempty"` BucketName string `xml:"BucketName,omitempty" json:"BucketName,omitempty"` Resource string Region string `xml:"Region,omitempty" json:"Region,omitempty"` RequestID string `xml:"RequestId" json:"RequestId"` HostID string `xml:"HostId" json:"HostId"` } // APIError structure Error struct { Code string Description string HTTPStatusCode int } ) const ( hdrServerInfo = "Server" hdrAcceptRanges = "Accept-Ranges" hdrContentType = "Content-Type" hdrContentLength = "Content-Length" hdrRetryAfter = "Retry-After" hdrAmzCopySource = "X-Amz-Copy-Source" // Response request id. hdrAmzRequestID = "x-amz-request-id" // hdrSSE is the general AWS SSE HTTP header key. hdrSSE = "X-Amz-Server-Side-Encryption" // hdrSSECustomerKey is the HTTP header key referencing the // SSE-C client-provided key.. hdrSSECustomerKey = hdrSSE + "-Customer-Key" // hdrSSECopyKey is the HTTP header key referencing the SSE-C // client-provided key for SSE-C copy requests. hdrSSECopyKey = "X-Amz-Copy-Source-Server-Side-Encryption-Customer-Key" ) var deploymentID, _ = uuid.NewRandom() // WriteErrorResponse writes error headers func WriteErrorResponse(ctx context.Context, w http.ResponseWriter, err Error, reqURL *url.URL) { switch err.Code { case "SlowDown", "XNeoFSServerNotInitialized", "XNeoFSReadQuorum", "XNeoFSWriteQuorum": // Set retry-after header to indicate user-agents to retry request after 120secs. // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After w.Header().Set(hdrRetryAfter, "120") case "AccessDenied": // TODO process when the request is from browser and also if browser } // Generate error response. errorResponse := getAPIErrorResponse(ctx, err, reqURL.Path, w.Header().Get(hdrAmzRequestID), deploymentID.String()) encodedErrorResponse := encodeResponse(errorResponse) writeResponse(w, err.HTTPStatusCode, encodedErrorResponse, mimeXML) } // If none of the http routes match respond with appropriate errors func errorResponseHandler(w http.ResponseWriter, r *http.Request) { desc := fmt.Sprintf("Unknown API request at %s", r.URL.Path) WriteErrorResponse(r.Context(), w, Error{ Code: "XMinioUnknownAPIRequest", Description: desc, HTTPStatusCode: http.StatusBadRequest, }, r.URL) } // Write http common headers func setCommonHeaders(w http.ResponseWriter) { w.Header().Set(hdrServerInfo, "NeoFS-S3-Gate/"+misc.Version) w.Header().Set(hdrAcceptRanges, "bytes") // Remove sensitive information removeSensitiveHeaders(w.Header()) } // removeSensitiveHeaders removes confidential encryption // information - e.g. the SSE-C key - from the HTTP headers. // It has the same semantics as RemoveSensitiveEntires. func removeSensitiveHeaders(h http.Header) { h.Del(hdrSSECustomerKey) h.Del(hdrSSECopyKey) } func writeResponse(w http.ResponseWriter, statusCode int, response []byte, mType mimeType) { setCommonHeaders(w) if mType != mimeNone { w.Header().Set(hdrContentType, string(mType)) } w.Header().Set(hdrContentLength, strconv.Itoa(len(response))) w.WriteHeader(statusCode) if response != nil { _, _ = w.Write(response) w.(http.Flusher).Flush() } } // Encodes the response headers into XML format. func encodeResponse(response interface{}) []byte { var bytesBuffer bytes.Buffer bytesBuffer.WriteString(xml.Header) _ = xml. NewEncoder(&bytesBuffer). Encode(response) return bytesBuffer.Bytes() }