7694723758
Complete Go starter kit for AI Code Battle with: - main.go: HTTP server with HMAC authentication, placeholder computeMoves() - game/ package: Shared utilities (types, auth, grid) for reuse - types.go: Game state types, Direction constants, Position, etc. - auth.go: HMAC-SHA256 signing/verification with timestamp validation - grid.go: Toroidal distance, BFS pathfinding, neighbor functions - Tests: Comprehensive test coverage for grid and auth utilities - Dockerfile: Multi-stage build with Go 1.24-alpine - README: Complete documentation with examples and protocol reference The starter kit provides a minimal working bot that holds position by default. Participants implement their strategy in computeMoves() using the provided grid utilities. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
48 lines
1.3 KiB
Go
48 lines
1.3 KiB
Go
// Package game provides authentication utilities for AI Code Battle bots.
|
|
package game
|
|
|
|
import (
|
|
"crypto/hmac"
|
|
"crypto/sha256"
|
|
"encoding/hex"
|
|
"fmt"
|
|
"strconv"
|
|
)
|
|
|
|
// VerifyRequest verifies the HMAC signature of an incoming request.
|
|
func VerifyRequest(secret string, headers AuthHeaders, body []byte) bool {
|
|
// Verify timestamp is within allowed window
|
|
if headers.Timestamp != "" && !VerifyTimestamp(headers.Timestamp) {
|
|
return false
|
|
}
|
|
|
|
// Compute expected signature
|
|
bodyHash := sha256.Sum256(body)
|
|
signingString := fmt.Sprintf("%s.%s.%s.%s",
|
|
headers.MatchID,
|
|
headers.Turn,
|
|
headers.Timestamp,
|
|
hex.EncodeToString(bodyHash[:]))
|
|
|
|
mac := hmac.New(sha256.New, []byte(secret))
|
|
mac.Write([]byte(signingString))
|
|
expectedSig := hex.EncodeToString(mac.Sum(nil))
|
|
|
|
// Constant-time comparison to prevent timing attacks
|
|
return hmac.Equal([]byte(headers.Signature), []byte(expectedSig))
|
|
}
|
|
|
|
// SignResponse generates the HMAC signature for a response.
|
|
func SignResponse(secret, matchID, turnStr string, body []byte) string {
|
|
bodyHash := sha256.Sum256(body)
|
|
turn, _ := strconv.Atoi(turnStr)
|
|
|
|
signingString := fmt.Sprintf("%s.%d.%s",
|
|
matchID,
|
|
turn,
|
|
hex.EncodeToString(bodyHash[:]))
|
|
|
|
mac := hmac.New(sha256.New, []byte(secret))
|
|
mac.Write([]byte(signingString))
|
|
return hex.EncodeToString(mac.Sum(nil))
|
|
}
|