Files

80 lines
2.7 KiB
TypeScript

import 'server-only'
import fs from 'node:fs'
import path from 'node:path'
import crypto from 'node:crypto'
import { fileTypeFromBuffer } from 'file-type'
export type EvidenceStage = 'report' | 'response' | 'investigation' | 'capa' | 'verification'
const ALLOWED_MIME_TYPES = new Set([
'image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/heic', 'image/avif',
'video/mp4', 'video/quicktime', 'video/webm', 'video/x-msvideo',
'application/pdf',
'application/msword',
'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
'application/vnd.ms-excel',
'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
])
function evidenceDir(): string {
const dir = process.env.EVIDENCE_DIR
if (!dir) throw new Error('EVIDENCE_DIR env var not set')
return dir
}
function hmacSecret(): string {
const s = process.env.EVIDENCE_URL_SECRET
if (!s) throw new Error('EVIDENCE_URL_SECRET env var not set')
return s
}
export function signEvidencePath(filePath: string): string {
return crypto.createHmac('sha256', hmacSecret()).update(filePath).digest('hex')
}
export function getEvidenceUrl(filePath: string): string {
const token = signEvidencePath(filePath)
return `/api/evidence/${filePath}?token=${token}`
}
export async function uploadEvidenceFile(
file: File,
incidentId: string,
stage: EvidenceStage,
userId: string,
): Promise<{ path: string; publicUrl: string; hash: string }> {
const isVideo = file.type.startsWith('video/')
const maxBytes = isVideo ? 200 * 1024 * 1024 : 10 * 1024 * 1024
if (file.size > maxBytes) {
throw new Error(`File too large: max ${isVideo ? '200MB' : '10MB'} for this file type`)
}
const buffer = await file.arrayBuffer()
const detected = await fileTypeFromBuffer(buffer)
const detectedMime = detected?.mime ?? null
if (!detectedMime || !ALLOWED_MIME_TYPES.has(detectedMime)) {
throw new Error(`File type not allowed: ${detectedMime ?? 'unknown'}`)
}
const ext = detected?.ext ?? file.name.split('.').pop() ?? 'bin'
const filename = `${Date.now()}-${crypto.randomBytes(6).toString('hex')}.${ext}`
const filePath = `${userId}/${incidentId}/${stage}/${filename}`
const hash = await computeHashFromBuffer(buffer)
const fullPath = path.join(evidenceDir(), filePath)
fs.mkdirSync(path.dirname(fullPath), { recursive: true })
fs.writeFileSync(fullPath, Buffer.from(buffer))
const publicUrl = getEvidenceUrl(filePath)
return { path: filePath, publicUrl, hash }
}
async function computeHashFromBuffer(buffer: ArrayBuffer): Promise<string> {
const hashBuffer = await crypto.subtle.digest('SHA-256', buffer)
return Array.from(new Uint8Array(hashBuffer))
.map(b => b.toString(16).padStart(2, '0'))
.join('')
}