multica/server/pkg/redact/redact.go

// Package redact provides functions for detecting and masking secrets
// in agent output before it reaches the database or WebSocket broadcast.
package redact

import (
	"os"
	"os/user"
	"regexp"
	"strings"
)

// secretPattern pairs a compiled regex with its replacement text.
type secretPattern struct {
	re          *regexp.Regexp
	replacement string
}

// Patterns are checked in order; first match wins per position.
var patterns = []secretPattern{
	// AWS access key IDs (always start with AKIA)
	{regexp.MustCompile(`\bAKIA[0-9A-Z]{16}\b`), "[REDACTED AWS KEY]"},

	// AWS secret access keys (40 char base64-ish, preceded by a common separator)
	{regexp.MustCompile(`(?i)(?:aws_secret_access_key|secret_?access_?key)\s*[=:]\s*[A-Za-z0-9/+=]{40}`), "[REDACTED AWS SECRET]"},

	// PEM private keys (multi-line)
	{regexp.MustCompile(`(?s)-----BEGIN[A-Z\s]*PRIVATE KEY-----.*?-----END[A-Z\s]*PRIVATE KEY-----`), "[REDACTED PRIVATE KEY]"},

	// GitHub tokens (classic PAT, OAuth, user-to-server, server-to-server, refresh)
	{regexp.MustCompile(`\b(ghp|gho|ghu|ghs|ghr)_[A-Za-z0-9_]{36,255}\b`), "[REDACTED GITHUB TOKEN]"},

	// GitHub fine-grained personal access tokens use the github_pat_ prefix,
	// which the classic ghp_/gho_/... pattern above does not cover. Without
	// this line a fine-grained PAT emitted in agent output leaks unredacted
	// to the database and WebSocket broadcast.
	{regexp.MustCompile(`\bgithub_pat_[A-Za-z0-9_]{20,255}\b`), "[REDACTED GITHUB TOKEN]"},

	// OpenAI / Anthropic API keys
	{regexp.MustCompile(`\bsk-[A-Za-z0-9_-]{20,}\b`), "[REDACTED API KEY]"},

	// Slack bot/user/legacy tokens. The char class includes 'e' so the
	// newer xoxe- config/refresh tokens are covered alongside xoxb/p/o/r/a/s.
	{regexp.MustCompile(`\bxox[bporase]-[A-Za-z0-9\-]{10,}\b`), "[REDACTED SLACK TOKEN]"},

	// Slack app-level tokens use the xapp- prefix, which the xox*- rule above
	// does not match. Without this an app-level token echoed in agent output
	// leaks unredacted to the DB / WebSocket broadcast.
	{regexp.MustCompile(`\bxapp-[A-Za-z0-9-]{10,}\b`), "[REDACTED SLACK TOKEN]"},

	// GitLab personal access tokens
	{regexp.MustCompile(`\bglpat-[A-Za-z0-9_-]{20,}\b`), "[REDACTED GITLAB TOKEN]"},

	// Google API keys always start with the AIza prefix and are 39 chars total
	// (AIza + 35). Not covered by any rule above, so they would otherwise leak.
	{regexp.MustCompile(`\bAIza[0-9A-Za-z_\-]{35}\b`), "[REDACTED GOOGLE API KEY]"},

	// Stripe secret / restricted live keys (sk_live_ / rk_live_). The sk-
	// rule above only matches the hyphen form used by OpenAI/Anthropic; Stripe
	// uses an underscore, so live keys are not covered without this. Publishable
	// keys (pk_live_) are intentionally excluded — they are not secret.
	{regexp.MustCompile(`\b(?:sk|rk)_live_[0-9A-Za-z]{16,}\b`), "[REDACTED STRIPE KEY]"},

	// JWT tokens (three base64url segments)
	{regexp.MustCompile(`\bey[A-Za-z0-9_-]{10,}\.[A-Za-z0-9_-]{10,}\.[A-Za-z0-9_-]{10,}\b`), "[REDACTED JWT]"},

	// Generic "Bearer <token>" in output
	{regexp.MustCompile(`(?i)\bBearer\s+[A-Za-z0-9\-._~+/]+=*\b`), "Bearer [REDACTED]"},

	// Connection strings with embedded passwords
	{regexp.MustCompile(`(?i)(?:postgres|mysql|mongodb|redis|amqp)(?:ql)?://[^:\s]+:[^@\s]+@`), "[REDACTED CONNECTION STRING]@"},

	// Generic key=value patterns for common secret env var names
	{regexp.MustCompile(`(?i)(?:API_KEY|API_SECRET|SECRET_KEY|SECRET|ACCESS_TOKEN|AUTH_TOKEN|PRIVATE_KEY|DATABASE_URL|DB_PASSWORD|DB_URL|REDIS_URL|PASSWORD|TOKEN)\s*[=:]\s*\S+`), "[REDACTED CREDENTIAL]"},
}

// InputMap returns a copy of m with all string values passed through Text.
// Non-string values are preserved as-is.
func InputMap(m map[string]any) map[string]any {
	if m == nil {
		return nil
	}
	out := make(map[string]any, len(m))
	for k, v := range m {
		if s, ok := v.(string); ok {
			out[k] = Text(s)
		} else {
			out[k] = v
		}
	}
	return out
}

// homeDir is resolved once at init for path redaction.
var homeDir string
var username string

func init() {
	homeDir, _ = os.UserHomeDir()
	if u, err := user.Current(); err == nil {
		username = u.Username
	}
}

// Text scans the input string for known secret patterns and replaces
// matches with safe placeholders. It also masks the local user's home
// directory path to prevent leaking the username.
func Text(s string) string {
	for _, p := range patterns {
		s = p.re.ReplaceAllString(s, p.replacement)
	}

	// Redact home directory paths (e.g. /Users/john/ → /Users/****/).
	if homeDir != "" && username != "" {
		masked := strings.Replace(homeDir, username, "****", 1)
		s = strings.ReplaceAll(s, homeDir, masked)
	}

	return s
}