fixed memory read issue in http adapter

Author: phin1x

.gitignore

@@ -1,2 +1,3 @@
-idea
-cmd
+.idea
+cmd
+tests

adapter-http.go

@@ -44,12 +44,10 @@ func (h *HttpAdapter) SendRequest(url string, req *Request, additionalResponseDa
 		return nil, err
 	}
 
-	var body io.Reader
 	size := len(payload)
-
+	var body io.Reader
 	if req.File != nil && req.FileSize != -1 {
 		size += req.FileSize
-
 		body = io.MultiReader(bytes.NewBuffer(payload), req.File)
 	} else {
 		body = bytes.NewBuffer(payload)
@@ -79,13 +77,25 @@ func (h *HttpAdapter) SendRequest(url string, req *Request, additionalResponseDa
 		}
 	}
 
-	resp, err := NewResponseDecoder(httpResp.Body).Decode(additionalResponseData)
+	// buffer response to avoid read issues
+	buf := new(bytes.Buffer)
+	if httpResp.ContentLength > 0 {
+		buf.Grow(int(httpResp.ContentLength))
+	}
+	if _, err := io.Copy(buf, httpResp.Body); err != nil {
+		return nil, fmt.Errorf("unable to buffer response: %w", err)
+	}
+
+	ippResp, err := NewResponseDecoder(buf).Decode(additionalResponseData)
 	if err != nil {
 		return nil, err
 	}
 
-	err = resp.CheckForErrors()
-	return resp, err
+	if err = ippResp.CheckForErrors(); err != nil {
+		return nil, fmt.Errorf("received error IPP response: %w", err)
+	}
+
+	return ippResp, nil
 }
 
 func (h *HttpAdapter) GetHttpUri(namespace string, object interface{}) string {

adapter-socket.go

@@ -41,14 +41,14 @@ func NewSocketAdapter(host string, useTLS bool) *SocketAdapter {
 	}
 }
 
-//DoRequest performs the given IPP request to the given URL, returning the IPP response or an error if one occurred.
-//Additional data will be written to an io.Writer if additionalData is not nil
+// SendRequest performs the given IPP request to the given URL, returning the IPP response or an error if one occurred.
+// Additional data will be written to an io.Writer if additionalData is not nil
 func (h *SocketAdapter) SendRequest(url string, r *Request, additionalData io.Writer) (*Response, error) {
 	for i := 0; i < h.RequestRetryLimit; i++ {
 		// encode request
 		payload, err := r.Encode()
 		if err != nil {
-			return nil, fmt.Errorf("unable to encode IPP request: %v", err)
+			return nil, fmt.Errorf("unable to encode IPP request: %w", err)
 		}
 
 		var body io.Reader
@@ -64,7 +64,7 @@ func (h *SocketAdapter) SendRequest(url string, r *Request, additionalData io.Wr
 
 		req, err := http.NewRequest("POST", url, body)
 		if err != nil {
-			return nil, fmt.Errorf("unable to create HTTP request: %v", err)
+			return nil, fmt.Errorf("unable to create HTTP request: %w", err)
 		}
 
 		sock, err := h.GetSocket()
@@ -91,39 +91,42 @@ func (h *SocketAdapter) SendRequest(url string, r *Request, additionalData io.Wr
 		}
 
 		// send request
-		resp, err := unixClient.Do(req)
+		httpResp, err := unixClient.Do(req)
 		if err != nil {
-			return nil, fmt.Errorf("unable to perform HTTP request: %v", err)
+			return nil, fmt.Errorf("unable to perform HTTP request: %w", err)
 		}
 
-		if resp.StatusCode == http.StatusUnauthorized {
+		if httpResp.StatusCode == http.StatusUnauthorized {
 			// retry with newly generated cert
-			resp.Body.Close()
+			httpResp.Body.Close()
 			continue
 		}
 
-		if resp.StatusCode != http.StatusOK {
-			resp.Body.Close()
-			return nil, fmt.Errorf("server did not return Status OK: %d", resp.StatusCode)
+		if httpResp.StatusCode != http.StatusOK {
+			httpResp.Body.Close()
+			return nil, fmt.Errorf("server did not return Status OK: %d", httpResp.StatusCode)
 		}
 
 		// buffer response to avoid read issues
 		buf := new(bytes.Buffer)
-		if _, err := io.Copy(buf, resp.Body); err != nil {
-			resp.Body.Close()
-			return nil, fmt.Errorf("unable to buffer response: %v", err)
+		if httpResp.ContentLength > 0 {
+			buf.Grow(int(httpResp.ContentLength))
+		}
+		if _, err := io.Copy(buf, httpResp.Body); err != nil {
+			httpResp.Body.Close()
+			return nil, fmt.Errorf("unable to buffer response: %w", err)
 		}
 
-		resp.Body.Close()
+		httpResp.Body.Close()
 
 		// decode reply
-		ippResp, err := NewResponseDecoder(bytes.NewReader(buf.Bytes())).Decode(additionalData)
+		ippResp, err := NewResponseDecoder(buf).Decode(additionalData)
 		if err != nil {
-			return nil, fmt.Errorf("unable to decode IPP response: %v", err)
+			return nil, fmt.Errorf("unable to decode IPP response: %w", err)
 		}
 
 		if err = ippResp.CheckForErrors(); err != nil {
-			return nil, fmt.Errorf("received error IPP response: %v", err)
+			return nil, fmt.Errorf("received error IPP response: %w", err)
 		}
 
 		return ippResp, nil
@@ -132,7 +135,7 @@ func (h *SocketAdapter) SendRequest(url string, r *Request, additionalData io.Wr
 	return nil, errors.New("request retry limit exceeded")
 }
 
-//GetSocket returns the path to the cupsd socket by searching SocketSearchPaths
+// GetSocket returns the path to the cupsd socket by searching SocketSearchPaths
 func (h *SocketAdapter) GetSocket() (string, error) {
 	for _, path := range h.SocketSearchPaths {
 		fi, err := os.Stat(path)
@@ -142,7 +145,7 @@ func (h *SocketAdapter) GetSocket() (string, error) {
 			} else if os.IsPermission(err) {
 				return "", errors.New("unable to access socket: Access denied")
 			}
-			return "", fmt.Errorf("unable to access socket: %v", err)
+			return "", fmt.Errorf("unable to access socket: %w", err)
 		}
 
 		if fi.Mode()&os.ModeSocket != 0 {
@@ -153,7 +156,7 @@ func (h *SocketAdapter) GetSocket() (string, error) {
 	return "", SocketNotFoundError
 }
 
-//GetCert returns the current CUPs authentication certificate by searching CertSearchPaths
+// GetCert returns the current CUPs authentication certificate by searching CertSearchPaths
 func (h *SocketAdapter) GetCert() (string, error) {
 	for _, path := range h.CertSearchPaths {
 		f, err := os.Open(path)
@@ -163,13 +166,13 @@ func (h *SocketAdapter) GetCert() (string, error) {
 			} else if os.IsPermission(err) {
 				return "", errors.New("unable to access certificate: Access denied")
 			}
-			return "", fmt.Errorf("unable to access certificate: %v", err)
+			return "", fmt.Errorf("unable to access certificate: %w", err)
 		}
 		defer f.Close()
 
 		buf := new(bytes.Buffer)
 		if _, err := io.Copy(buf, f); err != nil {
-			return "", fmt.Errorf("unable to access certificate: %v", err)
+			return "", fmt.Errorf("unable to access certificate: %w", err)
 		}
 		return buf.String(), nil
 	}