fix: address PR review feedback

- Fix SSRF: validate API endpoint host against allowlist before use
- Limit /models response body to 2MB to prevent memory exhaustion (DoS)
- Use MakeAuthenticatedRequest for consistent headers across API calls
- Trim trailing slash on API endpoint to prevent double-slash URLs
- Use ListModelsWithGitHubToken to simplify token exchange + listing
- Deduplicate model IDs to prevent incorrect registry reference counting
- Remove dead capabilities enrichment code block
- Remove unused ModelExtra field with misleading json:"-" tag
- Extract magic numbers to named constants (defaultCopilotContextLength)
- Remove redundant hyphenID == id check (already filtered by Contains)
- Use defer cancel() for context timeout in service.go

internal/auth/copilot/copilot_auth.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
+	"strings"
 	"time"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
@@ -224,14 +226,13 @@ func (c *CopilotAuth) MakeAuthenticatedRequest(ctx context.Context, method, url
 
 // CopilotModelEntry represents a single model entry returned by the Copilot /models API.
 type CopilotModelEntry struct {
-	ID         string                 `json:"id"`
-	Object     string                 `json:"object"`
-	Created    int64                  `json:"created"`
-	OwnedBy   string                 `json:"owned_by"`
-	Name       string                 `json:"name,omitempty"`
-	Version    string                 `json:"version,omitempty"`
-	Capabilities map[string]any       `json:"capabilities,omitempty"`
-	ModelExtra map[string]any         `json:"-"` // catch-all for unknown fields
+	ID           string         `json:"id"`
+	Object       string         `json:"object"`
+	Created      int64          `json:"created"`
+	OwnedBy      string         `json:"owned_by"`
+	Name         string         `json:"name,omitempty"`
+	Version      string         `json:"version,omitempty"`
+	Capabilities map[string]any `json:"capabilities,omitempty"`
 }
 
 // CopilotModelsResponse represents the response from the Copilot /models endpoint.
@@ -240,6 +241,17 @@ type CopilotModelsResponse struct {
 	Object string              `json:"object"`
 }
 
+// maxModelsResponseSize is the maximum allowed response size from the /models endpoint (2 MB).
+const maxModelsResponseSize = 2 * 1024 * 1024
+
+// allowedCopilotAPIHosts is the set of hosts that are considered safe for Copilot API requests.
+var allowedCopilotAPIHosts = map[string]bool{
+	"api.githubcopilot.com":          true,
+	"api.individual.githubcopilot.com": true,
+	"api.business.githubcopilot.com":   true,
+	"copilot-proxy.githubusercontent.com": true,
+}
+
 // ListModels fetches the list of available models from the Copilot API.
 // It requires a valid Copilot API token (not the GitHub access token).
 func (c *CopilotAuth) ListModels(ctx context.Context, apiToken *CopilotAPIToken) ([]CopilotModelEntry, error) {
@@ -247,23 +259,22 @@ func (c *CopilotAuth) ListModels(ctx context.Context, apiToken *CopilotAPIToken)
 		return nil, fmt.Errorf("copilot: api token is required for listing models")
 	}
 
+	// Build models URL, validating the endpoint host to prevent SSRF.
 	modelsURL := copilotAPIEndpoint + "/models"
-	if apiToken.Endpoints.API != "" {
-		modelsURL = apiToken.Endpoints.API + "/models"
+	if ep := strings.TrimRight(apiToken.Endpoints.API, "/"); ep != "" {
+		parsed, err := url.Parse(ep)
+		if err == nil && parsed.Scheme == "https" && allowedCopilotAPIHosts[parsed.Host] {
+			modelsURL = ep + "/models"
+		} else {
+			log.Warnf("copilot: ignoring untrusted API endpoint %q, using default", ep)
+		}
 	}
 
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, modelsURL, nil)
+	req, err := c.MakeAuthenticatedRequest(ctx, http.MethodGet, modelsURL, nil, apiToken)
 	if err != nil {
 		return nil, fmt.Errorf("copilot: failed to create models request: %w", err)
 	}
 
-	req.Header.Set("Authorization", "Bearer "+apiToken.Token)
-	req.Header.Set("Accept", "application/json")
-	req.Header.Set("User-Agent", copilotUserAgent)
-	req.Header.Set("Editor-Version", copilotEditorVersion)
-	req.Header.Set("Editor-Plugin-Version", copilotPluginVersion)
-	req.Header.Set("Copilot-Integration-Id", copilotIntegrationID)
-
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("copilot: models request failed: %w", err)
@@ -274,7 +285,9 @@ func (c *CopilotAuth) ListModels(ctx context.Context, apiToken *CopilotAPIToken)
 		}
 	}()
 
-	bodyBytes, err := io.ReadAll(resp.Body)
+	// Limit response body to prevent memory exhaustion.
+	limitedReader := io.LimitReader(resp.Body, maxModelsResponseSize)
+	bodyBytes, err := io.ReadAll(limitedReader)
 	if err != nil {
 		return nil, fmt.Errorf("copilot: failed to read models response: %w", err)
 	}

internal/config/oauth_model_alias_defaults.go

@@ -50,9 +50,6 @@ func GitHubCopilotAliasesFromModels(modelIDs []string) []OAuthModelAlias {
 			continue
 		}
 		hyphenID := strings.ReplaceAll(id, ".", "-")
-		if hyphenID == id {
-			continue
-		}
 		key := id + "→" + hyphenID
 		if _, ok := seen[key]; ok {
 			continue

internal/runtime/executor/github_copilot_executor.go

@@ -1266,6 +1266,13 @@ func isHTTPSuccess(statusCode int) bool {
 	return statusCode >= 200 && statusCode < 300
 }
 
+const (
+	// defaultCopilotContextLength is the default context window for unknown Copilot models.
+	defaultCopilotContextLength = 128000
+	// defaultCopilotMaxCompletionTokens is the default max output tokens for unknown Copilot models.
+	defaultCopilotMaxCompletionTokens = 16384
+)
+
 // FetchGitHubCopilotModels dynamically fetches available models from the GitHub Copilot API.
 // It exchanges the GitHub access token stored in auth.Metadata for a Copilot API token,
 // then queries the /models endpoint. Falls back to the static registry on any failure.
@@ -1283,13 +1290,7 @@ func FetchGitHubCopilotModels(ctx context.Context, auth *cliproxyauth.Auth, cfg
 
 	copilotAuth := copilotauth.NewCopilotAuth(cfg)
 
-	apiToken, err := copilotAuth.GetCopilotAPIToken(ctx, accessToken)
-	if err != nil {
-		log.Warnf("github-copilot: failed to get API token for model listing: %v, using static models", err)
-		return registry.GetGitHubCopilotModels()
-	}
-
-	entries, err := copilotAuth.ListModels(ctx, apiToken)
+	entries, err := copilotAuth.ListModelsWithGitHubToken(ctx, accessToken)
 	if err != nil {
 		log.Warnf("github-copilot: failed to fetch dynamic models: %v, using static models", err)
 		return registry.GetGitHubCopilotModels()
@@ -1309,10 +1310,16 @@ func FetchGitHubCopilotModels(ctx context.Context, auth *cliproxyauth.Auth, cfg
 
 	now := time.Now().Unix()
 	models := make([]*registry.ModelInfo, 0, len(entries))
+	seen := make(map[string]struct{}, len(entries))
 	for _, entry := range entries {
 		if entry.ID == "" {
 			continue
 		}
+		// Deduplicate model IDs to avoid incorrect reference counting.
+		if _, dup := seen[entry.ID]; dup {
+			continue
+		}
+		seen[entry.ID] = struct{}{}
 
 		m := &registry.ModelInfo{
 			ID:      entry.ID,
@@ -1331,11 +1338,6 @@ func FetchGitHubCopilotModels(ctx context.Context, auth *cliproxyauth.Auth, cfg
 			m.DisplayName = entry.ID
 		}
 
-		// Enrich from capabilities if available
-		if caps, ok := entry.Capabilities["type"].(string); ok && caps != "" {
-			_ = caps // reserved for future use
-		}
-
 		// Merge known metadata from the static fallback list
 		if static, ok := staticMap[entry.ID]; ok {
 			if m.DisplayName == entry.ID && static.DisplayName != "" {
@@ -1349,8 +1351,8 @@ func FetchGitHubCopilotModels(ctx context.Context, auth *cliproxyauth.Auth, cfg
 		} else {
 			// Sensible defaults for models not in the static list
 			m.Description = entry.ID + " via GitHub Copilot"
-			m.ContextLength = 128000
-			m.MaxCompletionTokens = 16384
+			m.ContextLength = defaultCopilotContextLength
+			m.MaxCompletionTokens = defaultCopilotMaxCompletionTokens
 		}
 
 		models = append(models, m)

sdk/cliproxy/service.go

@@ -867,8 +867,8 @@ func (s *Service) registerModelsForAuth(a *coreauth.Auth) {
     models = applyExcludedModels(models, excluded)
 	case "github-copilot":
 		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+		defer cancel()
 		models = executor.FetchGitHubCopilotModels(ctx, a, s.cfg)
-		cancel()
 		models = applyExcludedModels(models, excluded)
 	case "kiro":
 		models = s.fetchKiroModels(a)