e51c9e50b5
- Sync cc_version in x-anthropic-billing-header with the fingerprint User-Agent version, preserving the message-derived suffix - Implement xxHash64-based CCH signing to replace the cch=00000 placeholder with a computed hash - Add admin toggle (enable_cch_signing) under gateway forwarding settings, disabled by default
74 lines
2.3 KiB
Go
74 lines
2.3 KiB
Go
package service
|
|
|
|
import (
|
|
"fmt"
|
|
"regexp"
|
|
"strings"
|
|
|
|
"github.com/cespare/xxhash/v2"
|
|
"github.com/tidwall/gjson"
|
|
"github.com/tidwall/sjson"
|
|
)
|
|
|
|
// ccVersionInBillingRe matches the semver part of cc_version (X.Y.Z), preserving
|
|
// the trailing message-derived suffix (e.g. ".c02") if present.
|
|
var ccVersionInBillingRe = regexp.MustCompile(`cc_version=\d+\.\d+\.\d+`)
|
|
|
|
// cchPlaceholderRe matches the cch=00000 placeholder in billing header text,
|
|
// scoped to x-anthropic-billing-header to avoid touching user content.
|
|
var cchPlaceholderRe = regexp.MustCompile(`(x-anthropic-billing-header:[^"]*?\bcch=)(00000)(;)`)
|
|
|
|
const cchSeed uint64 = 0x6E52736AC806831E
|
|
|
|
// syncBillingHeaderVersion rewrites cc_version in x-anthropic-billing-header
|
|
// system text blocks to match the version extracted from userAgent.
|
|
// Only touches system array blocks whose text starts with "x-anthropic-billing-header".
|
|
func syncBillingHeaderVersion(body []byte, userAgent string) []byte {
|
|
version := ExtractCLIVersion(userAgent)
|
|
if version == "" {
|
|
return body
|
|
}
|
|
|
|
systemResult := gjson.GetBytes(body, "system")
|
|
if !systemResult.Exists() || !systemResult.IsArray() {
|
|
return body
|
|
}
|
|
|
|
replacement := "cc_version=" + version
|
|
idx := 0
|
|
systemResult.ForEach(func(_, item gjson.Result) bool {
|
|
text := item.Get("text")
|
|
if text.Exists() && text.Type == gjson.String &&
|
|
strings.HasPrefix(text.String(), "x-anthropic-billing-header") {
|
|
newText := ccVersionInBillingRe.ReplaceAllString(text.String(), replacement)
|
|
if newText != text.String() {
|
|
if updated, err := sjson.SetBytes(body, fmt.Sprintf("system.%d.text", idx), newText); err == nil {
|
|
body = updated
|
|
}
|
|
}
|
|
}
|
|
idx++
|
|
return true
|
|
})
|
|
|
|
return body
|
|
}
|
|
|
|
// signBillingHeaderCCH computes the xxHash64-based CCH signature for the request
|
|
// body and replaces the cch=00000 placeholder with the computed 5-hex-char hash.
|
|
// The body must contain the placeholder when this function is called.
|
|
func signBillingHeaderCCH(body []byte) []byte {
|
|
if !cchPlaceholderRe.Match(body) {
|
|
return body
|
|
}
|
|
cch := fmt.Sprintf("%05x", xxHash64Seeded(body, cchSeed)&0xFFFFF)
|
|
return cchPlaceholderRe.ReplaceAll(body, []byte("${1}"+cch+"${3}"))
|
|
}
|
|
|
|
// xxHash64Seeded computes xxHash64 of data with a custom seed.
|
|
func xxHash64Seeded(data []byte, seed uint64) uint64 {
|
|
d := xxhash.NewWithSeed(seed)
|
|
d.Write(data)
|
|
return d.Sum64()
|
|
}
|