Files
goreplay/examples/middleware/token_modifier.go
T
2015-08-15 10:33:50 +03:00

98 lines
2.4 KiB
Go

package main
import (
"bufio"
"bytes"
"encoding/hex"
"fmt"
"github.com/buger/gor/proto"
"os"
)
// requestID -> originalToken
var originalTokens map[string][]byte
// originalToken -> replayedToken
var tokenAliases map[string][]byte
func main() {
originalTokens = make(map[string][]byte)
tokenAliases = make(map[string][]byte)
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
encoded := scanner.Bytes()
buf := make([]byte, len(encoded)/2)
hex.Decode(buf, encoded)
go process(buf)
}
}
func process(buf []byte) {
// First byte indicate payload type, possible values:
// 1 - Request
// 2 - Response
// 3 - ReplayedResponse
payloadType := buf[0]
headerSize := 42
header := buf[:headerSize]
// For each request you should receive 3 payloads (request, response, replayed response) with same request id
reqID := string(header[2:headerSize])
payload := buf[headerSize:]
Debug("Received payload:", string(buf))
switch payloadType {
case '1': // Request
if bytes.Equal(proto.Path(payload), []byte("/token")) {
originalTokens[reqID] = []byte{}
Debug("Found token request:", reqID)
} else {
tokenVal, vs, _ := proto.PathParam(payload, []byte("token"))
if vs != -1 { // If there is GET token param
if alias, ok := tokenAliases[string(tokenVal)]; ok {
// Rewrite original token to alias
payload = proto.SetPathParam(payload, []byte("token"), alias)
// Copy modified payload to our buffer
copy(buf[headerSize:], payload)
}
}
}
// Re-compute length in case if payload was modified
bufLen := len(header) + len(payload)
// Encoding request and sending it back
dst := make([]byte, bufLen*2+1)
hex.Encode(dst, buf[:bufLen])
dst[len(dst)-1] = '\n'
os.Stdout.Write(dst)
return
case '2': // Original response
if _, ok := originalTokens[reqID]; ok {
// Token is inside response body
secureToken := proto.Body(payload)
originalTokens[reqID] = secureToken
Debug("Remember origial token:", string(secureToken))
}
case '3': // Replayed response
if originalToken, ok := originalTokens[reqID]; ok {
delete(originalTokens, reqID)
secureToken := proto.Body(payload)
tokenAliases[string(originalToken)] = secureToken
Debug("Create alias for new token token, was:", string(originalToken), "now:", string(secureToken))
}
}
}
func Debug(args ...interface{}) {
fmt.Fprint(os.Stderr, "[DEBUG][TOKEN-MOD] ")
fmt.Fprintln(os.Stderr, args...)
}