add default mode

internal/proxy/modifier.go

@@ -0,0 +1,199 @@
+package proxy
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/wso2/open-mcp-auth-proxy/internal/config"
+)
+
+// RequestModifier modifies requests before they are proxied
+type RequestModifier interface {
+	ModifyRequest(req *http.Request) (*http.Request, error)
+}
+
+// AuthorizationModifier adds parameters to authorization requests
+type AuthorizationModifier struct {
+	Config *config.Config
+}
+
+// TokenModifier adds parameters to token requests
+type TokenModifier struct {
+	Config *config.Config
+}
+
+type RegisterModifier struct {
+	Config *config.Config
+}
+
+// ModifyRequest adds configured parameters to authorization requests
+func (m *AuthorizationModifier) ModifyRequest(req *http.Request) (*http.Request, error) {
+	// Check if we have parameters to add
+	if m.Config.Default.Path == nil {
+		return req, nil
+	}
+
+	pathConfig, exists := m.Config.Default.Path["/authorize"]
+	if !exists || len(pathConfig.AddQueryParams) == 0 {
+		return req, nil
+	}
+	// Get current query parameters
+	query := req.URL.Query()
+
+	// Add parameters from config
+	for _, param := range pathConfig.AddQueryParams {
+		query.Set(param.Name, param.Value)
+	}
+
+	// Update the request URL
+	req.URL.RawQuery = query.Encode()
+
+	return req, nil
+}
+
+// ModifyRequest adds configured parameters to token requests
+func (m *TokenModifier) ModifyRequest(req *http.Request) (*http.Request, error) {
+	// Only modify POST requests
+	if req.Method != http.MethodPost {
+		return req, nil
+	}
+
+	// Check if we have parameters to add
+	if m.Config.Default.Path == nil {
+		return req, nil
+	}
+
+	pathConfig, exists := m.Config.Default.Path["/token"]
+	if !exists || len(pathConfig.AddBodyParams) == 0 {
+		return req, nil
+	}
+
+	contentType := req.Header.Get("Content-Type")
+
+	if strings.Contains(contentType, "application/x-www-form-urlencoded") {
+		// Parse form data
+		if err := req.ParseForm(); err != nil {
+			return nil, err
+		}
+
+		// Clone form data
+		formData := req.PostForm
+
+		// Add configured parameters
+		for _, param := range pathConfig.AddBodyParams {
+			formData.Set(param.Name, param.Value)
+		}
+
+		// Create new request body with modified form
+		formEncoded := formData.Encode()
+		req.Body = io.NopCloser(strings.NewReader(formEncoded))
+		req.ContentLength = int64(len(formEncoded))
+		req.Header.Set("Content-Length", fmt.Sprintf("%d", len(formEncoded)))
+
+	} else if strings.Contains(contentType, "application/json") {
+		// Read body
+		bodyBytes, err := io.ReadAll(req.Body)
+		if err != nil {
+			return nil, err
+		}
+
+		// Parse JSON
+		var jsonData map[string]interface{}
+		if err := json.Unmarshal(bodyBytes, &jsonData); err != nil {
+			return nil, err
+		}
+
+		// Add parameters
+		for _, param := range pathConfig.AddBodyParams {
+			jsonData[param.Name] = param.Value
+		}
+
+		// Marshal back to JSON
+		modifiedBody, err := json.Marshal(jsonData)
+		if err != nil {
+			return nil, err
+		}
+
+		// Update request
+		req.Body = io.NopCloser(bytes.NewReader(modifiedBody))
+		req.ContentLength = int64(len(modifiedBody))
+		req.Header.Set("Content-Length", fmt.Sprintf("%d", len(modifiedBody)))
+	}
+
+	return req, nil
+}
+
+func (m *RegisterModifier) ModifyRequest(req *http.Request) (*http.Request, error) {
+	// Only modify POST requests
+	if req.Method != http.MethodPost {
+		return req, nil
+	}
+
+	// Check if we have parameters to add
+	if m.Config.Default.Path == nil {
+		return req, nil
+	}
+
+	pathConfig, exists := m.Config.Default.Path["/register"]
+	if !exists || len(pathConfig.AddBodyParams) == 0 {
+		return req, nil
+	}
+
+	contentType := req.Header.Get("Content-Type")
+
+	if strings.Contains(contentType, "application/x-www-form-urlencoded") {
+		// Parse form data
+		if err := req.ParseForm(); err != nil {
+			return nil, err
+		}
+
+		// Clone form data
+		formData := req.PostForm
+
+		// Add configured parameters
+		for _, param := range pathConfig.AddBodyParams {
+			formData.Set(param.Name, param.Value)
+		}
+
+		// Create new request body with modified form
+		formEncoded := formData.Encode()
+		req.Body = io.NopCloser(strings.NewReader(formEncoded))
+		req.ContentLength = int64(len(formEncoded))
+		req.Header.Set("Content-Length", fmt.Sprintf("%d", len(formEncoded)))
+
+	} else if strings.Contains(contentType, "application/json") {
+		// Read body
+		bodyBytes, err := io.ReadAll(req.Body)
+		if err != nil {
+			return nil, err
+		}
+
+		// Parse JSON
+		var jsonData map[string]interface{}
+		if err := json.Unmarshal(bodyBytes, &jsonData); err != nil {
+			return nil, err
+		}
+
+		// Add parameters
+		for _, param := range pathConfig.AddBodyParams {
+			jsonData[param.Name] = param.Value
+		}
+
+		// Marshal back to JSON
+		modifiedBody, err := json.Marshal(jsonData)
+		if err != nil {
+			return nil, err
+		}
+
+		// Update request
+		req.Body = io.NopCloser(bytes.NewReader(modifiedBody))
+		req.ContentLength = int64(len(modifiedBody))
+		req.Header.Set("Content-Length", fmt.Sprintf("%d", len(modifiedBody)))
+	}
+
+	return req, nil
+}