opensource/sub2api
3
0
Fork 0
mirror of https://github.com/Wei-Shaw/sub2api.git synced 2026-09-24 16:05:44 +08:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #3843 from InCerryGit/fix/issue-3540-lenient-json-limit

Browse Source 
fix(gateway): cap lenient JSON normalization
This commit is contained in:
Wesley Liddick
2026-07-09 14:39:55 +08:00
committed by GitHub
parent e2c662e965 53a5c45bd8
commit dfff28ab05
9 changed files with 291 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files
backend/internal/handler/gateway_handler.go
+2 -3
View File
@@ -20,7 +20,6 @@ import (
"github.com/Wei-Shaw/sub2api/internal/pkg/ctxkey"
pkgerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
"github.com/Wei-Shaw/sub2api/internal/pkg/geminicli"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
"github.com/Wei-Shaw/sub2api/internal/pkg/ip"
"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
@@ -138,7 +137,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
defer h.maybeLogCompatibilityFallbackMetrics(reqLog)
// 读取请求体
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.errorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
@@ -1777,7 +1776,7 @@ func (h *GatewayHandler) CountTokens(c *gin.Context) {
defer h.maybeLogCompatibilityFallbackMetrics(reqLog)
// 读取请求体
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.errorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
backend/internal/handler/gateway_handler_chat_completions.go
+1 -2
View File
@@ -7,7 +7,6 @@ import (
"strconv"
"time"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
"github.com/Wei-Shaw/sub2api/internal/pkg/ip"
middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
"github.com/Wei-Shaw/sub2api/internal/service"
@@ -45,7 +44,7 @@ func (h *GatewayHandler) ChatCompletions(c *gin.Context) {
)
// Read request body
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.chatCompletionsErrorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
backend/internal/handler/gateway_handler_responses.go
+1 -2
View File
@@ -7,7 +7,6 @@ import (
"strconv"
"time"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
"github.com/Wei-Shaw/sub2api/internal/pkg/ip"
middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
"github.com/Wei-Shaw/sub2api/internal/service"
@@ -45,7 +44,7 @@ func (h *GatewayHandler) Responses(c *gin.Context) {
)
// Read request body
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.responsesErrorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
backend/internal/handler/openai_chat_completions.go
+1 -2
View File
@@ -7,7 +7,6 @@ import (
"strconv"
"time"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
"github.com/Wei-Shaw/sub2api/internal/pkg/ip"
"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
"github.com/Wei-Shaw/sub2api/internal/pkg/openai_compat"
@@ -49,7 +48,7 @@ func (h *OpenAIGatewayHandler) ChatCompletions(c *gin.Context) {
return
}
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.errorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
backend/internal/handler/openai_gateway_count_tokens.go
+1 -2
View File
@@ -6,7 +6,6 @@ import (
"time"
"github.com/Wei-Shaw/sub2api/internal/domain"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
"github.com/Wei-Shaw/sub2api/internal/service"
@@ -47,7 +46,7 @@ func (h *OpenAIGatewayHandler) CountTokens(c *gin.Context) {
return
}
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.anthropicErrorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
backend/internal/handler/openai_gateway_handler.go
+2 -3
View File
@@ -13,7 +13,6 @@ import (
"github.com/Wei-Shaw/sub2api/internal/config"
"github.com/Wei-Shaw/sub2api/internal/pkg/ctxkey"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
"github.com/Wei-Shaw/sub2api/internal/pkg/ip"
"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
@@ -185,7 +184,7 @@ func (h *OpenAIGatewayHandler) Responses(c *gin.Context) {
}
// Read request body
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.errorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
@@ -715,7 +714,7 @@ func (h *OpenAIGatewayHandler) Messages(c *gin.Context) {
return
}
body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
body, err := readLenientJSONRequestBodyWithPrealloc(c.Request, h.cfg)
if err != nil {
if maxErr, ok := extractMaxBytesError(err); ok {
h.anthropicErrorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
backend/internal/handler/request_body_limit.go
+14
View File
@@ -4,6 +4,9 @@ import (
"errors"
"fmt"
"net/http"
"github.com/Wei-Shaw/sub2api/internal/config"
pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
)
func extractMaxBytesError(err error) (*http.MaxBytesError, bool) {
@@ -25,3 +28,14 @@ func formatBodyLimit(limit int64) string {
func buildBodyTooLargeMessage(limit int64) string {
return fmt.Sprintf("Request body too large, limit is %s", formatBodyLimit(limit))
}
func readLenientJSONRequestBodyWithPrealloc(req *http.Request, cfg *config.Config) ([]byte, error) {
return pkghttputil.ReadLenientJSONRequestBodyWithPrealloc(req, gatewayMaxBodySize(cfg))
}
func gatewayMaxBodySize(cfg *config.Config) int64 {
if cfg == nil {
return 0
}
return cfg.Gateway.MaxBodySize
}
backend/internal/pkg/httputil/body.go
+85
View File
@@ -16,6 +16,7 @@ import (
const (
requestBodyReadInitCap = 512
requestBodyReadMaxInitCap = 1 << 20
jsonUTF8BOMLen = 3
// maxDecompressedBodySize limits the decompressed request body to 64 MB
// to prevent decompression bomb attacks.
maxDecompressedBodySize = 64 << 20
@@ -64,6 +65,16 @@ func ReadRequestBodyWithPrealloc(req *http.Request) ([]byte, error) {
return decoded, nil
}
// ReadLenientJSONRequestBodyWithPrealloc reads a request body and normalizes
// JSON string control bytes before strict validation.
func ReadLenientJSONRequestBodyWithPrealloc(req *http.Request, maxNormalizedBytes int64) ([]byte, error) {
body, err := ReadRequestBodyWithPrealloc(req)
if err != nil {
return nil, err
}
return NormalizeLenientJSONRequestBody(body, maxNormalizedBytes)
}
func decompressRequestBody(encoding string, raw []byte) ([]byte, error) {
switch encoding {
case "zstd":
@@ -91,3 +102,77 @@ func decompressRequestBody(encoding string, raw []byte) ([]byte, error) {
return nil, errors.New("unsupported Content-Encoding")
}
}
// NormalizeLenientJSONRequestBody escapes raw control bytes that broken
// OpenAI-compatible clients sometimes place inside JSON strings.
func NormalizeLenientJSONRequestBody(body []byte, maxNormalizedBytes int64) ([]byte, error) {
if maxNormalizedBytes <= 0 {
maxNormalizedBytes = maxDecompressedBodySize
}
body = trimUTF8BOM(body)
if len(body) == 0 {
return body, nil
}
if int64(len(body)) > maxNormalizedBytes {
return nil, &http.MaxBytesError{Limit: maxNormalizedBytes}
}
var out []byte
inString := false
escaped := false
for i, b := range body {
if inString && isJSONControlByte(b) {
if out == nil {
capHint := len(body) + 6
if int64(capHint) > maxNormalizedBytes {
capHint = int(maxNormalizedBytes)
}
out = make([]byte, 0, capHint)
out = append(out, body[:i]...)
}
if int64(len(out)+6) > maxNormalizedBytes {
return nil, &http.MaxBytesError{Limit: maxNormalizedBytes}
}
out = appendJSONUnicodeEscape(out, b)
escaped = false
continue
}
switch {
case escaped:
escaped = false
case inString && b == '\\':
escaped = true
case b == '"':
inString = !inString
}
if out != nil {
if int64(len(out)+1) > maxNormalizedBytes {
return nil, &http.MaxBytesError{Limit: maxNormalizedBytes}
}
out = append(out, b)
}
}
if out != nil {
return out, nil
}
return body, nil
}
func trimUTF8BOM(body []byte) []byte {
if len(body) >= jsonUTF8BOMLen && body[0] == 0xef && body[1] == 0xbb && body[2] == 0xbf {
return body[jsonUTF8BOMLen:]
}
return body
}
func isJSONControlByte(b byte) bool {
return b < 0x20 || b == 0x7f
}
func appendJSONUnicodeEscape(dst []byte, b byte) []byte {
const hex = "0123456789abcdef"
return append(dst, '\\', 'u', '0', '0', hex[b>>4], hex[b&0x0f])
}
backend/internal/pkg/httputil/body_lenient_json_test.go
+184
View File
@@ -0,0 +1,184 @@
package httputil
import (
"bytes"
"errors"
"net/http"
"net/http/httptest"
"testing"
"github.com/tidwall/gjson"
)
func TestNormalizeLenientJSONRequestBody_accepts_client_control_chars_in_strings(t *testing.T) {
tests := []struct {
name string
body []byte
path string
want string
wantRaw string
}{
{
name: "null byte in message content",
body: []byte("{\"messages\":[{\"content\":\"hello\x00world\"}]}"),
path: "messages.0.content",
want: "hello\x00world",
wantRaw: `"hello\u0000world"`,
},
{
name: "ansi escape in message content",
body: []byte("{\"messages\":[{\"content\":\"hello\x1b[31mred\x1b[0m\"}]}"),
path: "messages.0.content",
want: "hello\x1b[31mred\x1b[0m",
wantRaw: `"hello\u001b[31mred\u001b[0m"`,
},
{
name: "leading UTF-8 BOM",
body: []byte("\xef\xbb\xbf{\"input\":\"hello\"}"),
path: "input",
want: "hello",
wantRaw: `"hello"`,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// Given
if gjson.ValidBytes(tt.body) {
t.Fatalf("test payload should reproduce strict JSON rejection: %q", tt.body)
}
// When
got, err := NormalizeLenientJSONRequestBody(tt.body, 1024)
if err != nil {
t.Fatalf("NormalizeLenientJSONRequestBody: %v", err)
}
// Then
if !gjson.ValidBytes(got) {
t.Fatalf("normalized body should be valid JSON: %q", got)
}
result := gjson.GetBytes(got, tt.path)
if result.String() != tt.want {
t.Fatalf("value mismatch: got %q want %q", result.String(), tt.want)
}
if result.Raw != tt.wantRaw {
t.Fatalf("raw value mismatch: got %q want %q", result.Raw, tt.wantRaw)
}
})
}
}
func TestNormalizeLenientJSONRequestBody_keeps_invalid_structure_invalid(t *testing.T) {
tests := []struct {
name string
body []byte
}{
{
name: "truncated JSON",
body: []byte("{\"messages\":[{\"content\":\"hello\"}]"),
},
{
name: "control character outside string",
body: []byte("{\"input\":\"hello\"}\x00"),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// When
got, err := NormalizeLenientJSONRequestBody(tt.body, 1024)
if err != nil {
t.Fatalf("NormalizeLenientJSONRequestBody: %v", err)
}
// Then
if gjson.ValidBytes(got) {
t.Fatalf("normalization must not repair invalid JSON structure: %q", got)
}
})
}
}
func TestNormalizeLenientJSONRequestBody_allows_http_requests_with_client_control_chars(t *testing.T) {
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Given
body, err := ReadLenientJSONRequestBodyWithPrealloc(r, 1024)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
// When
if !gjson.ValidBytes(body) {
http.Error(w, "Failed to parse request body", http.StatusBadRequest)
return
}
w.WriteHeader(http.StatusAccepted)
}))
defer server.Close()
tests := []struct {
name string
body []byte
want int
}{
{
name: "null byte in JSON string",
body: []byte("{\"model\":\"gpt-5.5\",\"messages\":[{\"role\":\"user\",\"content\":\"hello\x00world\"}]}"),
want: http.StatusAccepted,
},
{
name: "ANSI escape in JSON string",
body: []byte("{\"model\":\"gpt-5.5\",\"messages\":[{\"role\":\"user\",\"content\":\"hello\x1b[31mred\x1b[0m\"}]}"),
want: http.StatusAccepted,
},
{
name: "leading UTF-8 BOM",
body: []byte("\xef\xbb\xbf{\"model\":\"gpt-5.5\",\"messages\":[{\"role\":\"user\",\"content\":\"hello\"}]}"),
want: http.StatusAccepted,
},
{
name: "truncated JSON",
body: []byte("{\"model\":\"gpt-5.5\",\"messages\":[{\"role\":\"user\",\"content\":\"hello\"}]"),
want: http.StatusBadRequest,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
req, err := http.NewRequest(http.MethodPost, server.URL+"/v1/chat/completions", bytes.NewReader(tt.body))
if err != nil {
t.Fatalf("NewRequest: %v", err)
}
req.Header.Set("Content-Type", "application/json")
resp, err := server.Client().Do(req)
if err != nil {
t.Fatalf("Do: %v", err)
}
defer func() { _ = resp.Body.Close() }()
if resp.StatusCode != tt.want {
t.Fatalf("status mismatch: got %d want %d", resp.StatusCode, tt.want)
}
})
}
}
func TestNormalizeLenientJSONRequestBody_rejects_expansion_past_limit(t *testing.T) {
// Given
body := []byte("{\"input\":\"\x00\x00\"}")
// When
_, err := NormalizeLenientJSONRequestBody(body, int64(len(body)+5))
// Then
var maxErr *http.MaxBytesError
if !errors.As(err, &maxErr) {
t.Fatalf("expected MaxBytesError, got %T %v", err, err)
}
if maxErr.Limit != int64(len(body)+5) {
t.Fatalf("limit mismatch: got %d want %d", maxErr.Limit, len(body)+5)
}
}