Handle compressed error decode failures safely

internal/runtime/executor/claude_executor.go

@@ -185,14 +185,25 @@ func (e *ClaudeExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	}
 	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
 	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
-		// Decompress error responses (e.g. gzip-compressed 400 errors from Anthropic API)
+		// Decompress error responses (e.g. gzip-compressed 400 errors from Anthropic API).
 		errBody := httpResp.Body
 		if ce := httpResp.Header.Get("Content-Encoding"); ce != "" {
-			if decoded, decErr := decodeResponseBody(httpResp.Body, ce); decErr == nil {
+			var decErr error
-				errBody = decoded
+			errBody, decErr = decodeResponseBody(httpResp.Body, ce)
+			if decErr != nil {
+				recordAPIResponseError(ctx, e.cfg, decErr)
+				msg := fmt.Sprintf("failed to decode error response body (encoding=%s): %v", ce, decErr)
+				logWithRequestID(ctx).Warn(msg)
+				return resp, statusErr{code: httpResp.StatusCode, msg: msg}
 			}
 		}
-		b, _ := io.ReadAll(errBody)
+		b, readErr := io.ReadAll(errBody)
+		if readErr != nil {
+			recordAPIResponseError(ctx, e.cfg, readErr)
+			msg := fmt.Sprintf("failed to read error response body: %v", readErr)
+			logWithRequestID(ctx).Warn(msg)
+			b = []byte(msg)
+		}
 		appendAPIResponseChunk(ctx, e.cfg, b)
 		logWithRequestID(ctx).Debugf("request error, error status: %d, error message: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
 		err = statusErr{code: httpResp.StatusCode, msg: string(b)}
@@ -339,14 +350,25 @@ func (e *ClaudeExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	}
 	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
 	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
-		// Decompress error responses (e.g. gzip-compressed 400 errors from Anthropic API)
+		// Decompress error responses (e.g. gzip-compressed 400 errors from Anthropic API).
 		errBody := httpResp.Body
 		if ce := httpResp.Header.Get("Content-Encoding"); ce != "" {
-			if decoded, decErr := decodeResponseBody(httpResp.Body, ce); decErr == nil {
+			var decErr error
-				errBody = decoded
+			errBody, decErr = decodeResponseBody(httpResp.Body, ce)
+			if decErr != nil {
+				recordAPIResponseError(ctx, e.cfg, decErr)
+				msg := fmt.Sprintf("failed to decode error response body (encoding=%s): %v", ce, decErr)
+				logWithRequestID(ctx).Warn(msg)
+				return nil, statusErr{code: httpResp.StatusCode, msg: msg}
 			}
 		}
-		b, _ := io.ReadAll(errBody)
+		b, readErr := io.ReadAll(errBody)
+		if readErr != nil {
+			recordAPIResponseError(ctx, e.cfg, readErr)
+			msg := fmt.Sprintf("failed to read error response body: %v", readErr)
+			logWithRequestID(ctx).Warn(msg)
+			b = []byte(msg)
+		}
 		appendAPIResponseChunk(ctx, e.cfg, b)
 		logWithRequestID(ctx).Debugf("request error, error status: %d, error message: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
 		if errClose := errBody.Close(); errClose != nil {
@@ -497,14 +519,25 @@ func (e *ClaudeExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Aut
 	}
 	recordAPIResponseMetadata(ctx, e.cfg, resp.StatusCode, resp.Header.Clone())
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		// Decompress error responses (e.g. gzip-compressed 400 errors from Anthropic API)
+		// Decompress error responses (e.g. gzip-compressed 400 errors from Anthropic API).
-		errBody := io.ReadCloser(resp.Body)
+		errBody := resp.Body
 		if ce := resp.Header.Get("Content-Encoding"); ce != "" {
-			if decoded, decErr := decodeResponseBody(resp.Body, ce); decErr == nil {
+			var decErr error
-				errBody = decoded
+			errBody, decErr = decodeResponseBody(resp.Body, ce)
+			if decErr != nil {
+				recordAPIResponseError(ctx, e.cfg, decErr)
+				msg := fmt.Sprintf("failed to decode error response body (encoding=%s): %v", ce, decErr)
+				logWithRequestID(ctx).Warn(msg)
+				return cliproxyexecutor.Response{}, statusErr{code: resp.StatusCode, msg: msg}
 			}
 		}
-		b, _ := io.ReadAll(errBody)
+		b, readErr := io.ReadAll(errBody)
+		if readErr != nil {
+			recordAPIResponseError(ctx, e.cfg, readErr)
+			msg := fmt.Sprintf("failed to read error response body: %v", readErr)
+			logWithRequestID(ctx).Warn(msg)
+			b = []byte(msg)
+		}
 		appendAPIResponseChunk(ctx, e.cfg, b)
 		if errClose := errBody.Close(); errClose != nil {
 			log.Errorf("response body close error: %v", errClose)

internal/runtime/executor/claude_executor_test.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
@@ -519,3 +520,66 @@ func hasTTLOrderingViolation(payload []byte) bool {
 
 	return violates
 }
+
+func TestClaudeExecutor_Execute_InvalidGzipErrorBodyReturnsDecodeMessage(t *testing.T) {
+	testClaudeExecutorInvalidCompressedErrorBody(t, func(executor *ClaudeExecutor, auth *cliproxyauth.Auth, payload []byte) error {
+		_, err := executor.Execute(context.Background(), auth, cliproxyexecutor.Request{
+			Model:   "claude-3-5-sonnet-20241022",
+			Payload: payload,
+		}, cliproxyexecutor.Options{SourceFormat: sdktranslator.FromString("claude")})
+		return err
+	})
+}
+
+func TestClaudeExecutor_ExecuteStream_InvalidGzipErrorBodyReturnsDecodeMessage(t *testing.T) {
+	testClaudeExecutorInvalidCompressedErrorBody(t, func(executor *ClaudeExecutor, auth *cliproxyauth.Auth, payload []byte) error {
+		_, err := executor.ExecuteStream(context.Background(), auth, cliproxyexecutor.Request{
+			Model:   "claude-3-5-sonnet-20241022",
+			Payload: payload,
+		}, cliproxyexecutor.Options{SourceFormat: sdktranslator.FromString("claude")})
+		return err
+	})
+}
+
+func TestClaudeExecutor_CountTokens_InvalidGzipErrorBodyReturnsDecodeMessage(t *testing.T) {
+	testClaudeExecutorInvalidCompressedErrorBody(t, func(executor *ClaudeExecutor, auth *cliproxyauth.Auth, payload []byte) error {
+		_, err := executor.CountTokens(context.Background(), auth, cliproxyexecutor.Request{
+			Model:   "claude-3-5-sonnet-20241022",
+			Payload: payload,
+		}, cliproxyexecutor.Options{SourceFormat: sdktranslator.FromString("claude")})
+		return err
+	})
+}
+
+func testClaudeExecutorInvalidCompressedErrorBody(
+	t *testing.T,
+	invoke func(executor *ClaudeExecutor, auth *cliproxyauth.Auth, payload []byte) error,
+) {
+	t.Helper()
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Encoding", "gzip")
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = w.Write([]byte("not-a-valid-gzip-stream"))
+	}))
+	defer server.Close()
+
+	executor := NewClaudeExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{Attributes: map[string]string{
+		"api_key":  "key-123",
+		"base_url": server.URL,
+	}}
+	payload := []byte(`{"messages":[{"role":"user","content":[{"type":"text","text":"hi"}]}]}`)
+
+	err := invoke(executor, auth, payload)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "failed to decode error response body") {
+		t.Fatalf("expected decode failure message, got: %v", err)
+	}
+	if statusProvider, ok := err.(interface{ StatusCode() int }); !ok || statusProvider.StatusCode() != http.StatusBadRequest {
+		t.Fatalf("expected status code 400, got: %v", err)
+	}
+}