Files
stack/apps/gateway/src/commands/command-authorization.service.ts

139 lines
4.2 KiB
TypeScript

import { createHash, randomUUID } from 'node:crypto';
import { Inject, Injectable } from '@nestjs/common';
import { eq, users as usersTable, type Db } from '@mosaicstack/db';
import type { CommandDef, SlashCommandPayload } from '@mosaicstack/types';
import { DB } from '../database/database.module.js';
import { COMMANDS_REDIS } from './commands.tokens.js';
export type CommandRole = 'admin' | 'member' | 'viewer';
export interface CommandApproval {
approvalId: string;
actionDigest: string;
actorId: string;
command: string;
expiresAt: string;
}
export interface CommandAuthorizationResult {
allowed: boolean;
reason?: string;
}
@Injectable()
export class CommandAuthorizationService {
constructor(
@Inject(DB) private readonly db: Db,
@Inject(COMMANDS_REDIS)
private readonly redis: {
get(key: string): Promise<string | null>;
set(key: string, value: string, ...args: string[]): Promise<unknown>;
del(key: string): Promise<number>;
},
) {}
async authorize(
command: CommandDef,
payload: SlashCommandPayload,
actorId: string,
approvalId?: string,
): Promise<CommandAuthorizationResult> {
const role = await this.resolveRole(actorId);
if (!role || !this.hasScope(role, command.scope)) {
return { allowed: false, reason: 'not authorized for this command scope' };
}
if (command.scope !== 'admin') return { allowed: true };
if (!approvalId) return { allowed: false, reason: 'durable approval is required' };
const actionDigest = this.actionDigest(command.name, payload);
const approved = await this.consumeApproval(approvalId, actorId, actionDigest);
return approved
? { allowed: true }
: {
allowed: false,
reason: 'approval is invalid, expired, replayed, or does not match this action',
};
}
async createApproval(
command: CommandDef,
payload: SlashCommandPayload,
actorId: string,
): Promise<CommandApproval | null> {
const role = await this.resolveRole(actorId);
if (!role || command.scope !== 'admin' || !this.hasScope(role, command.scope)) return null;
const approvalId = randomUUID();
const expiresAt = new Date(Date.now() + 5 * 60_000).toISOString();
const approval: CommandApproval = {
approvalId,
actionDigest: this.actionDigest(command.name, payload),
actorId,
command: command.name,
expiresAt,
};
await this.redis.set(this.key(approvalId), JSON.stringify(approval), 'EX', '300');
return approval;
}
private async resolveRole(actorId: string): Promise<CommandRole | null> {
const [user] = await this.db
.select({ role: usersTable.role })
.from(usersTable)
.where(eq(usersTable.id, actorId))
.limit(1);
const role = user?.role;
return role === 'admin' || role === 'member' || role === 'viewer' ? role : null;
}
private hasScope(role: CommandRole, scope: CommandDef['scope']): boolean {
if (role === 'admin') return true;
return role === 'member' && (scope === 'core' || scope === 'agent');
}
private async consumeApproval(
approvalId: string,
actorId: string,
actionDigest: string,
): Promise<boolean> {
const key = this.key(approvalId);
const encoded = await this.redis.get(key);
if (!encoded) return false;
const parsed: unknown = JSON.parse(encoded);
if (
!this.isApproval(parsed) ||
parsed.actorId !== actorId ||
parsed.actionDigest !== actionDigest ||
Date.parse(parsed.expiresAt) <= Date.now()
)
return false;
return (await this.redis.del(key)) === 1;
}
private actionDigest(command: string, payload: SlashCommandPayload): string {
return createHash('sha256')
.update(
JSON.stringify({
command,
args: payload.args?.trim() ?? '',
conversationId: payload.conversationId,
}),
)
.digest('hex');
}
private isApproval(value: unknown): value is CommandApproval {
return (
typeof value === 'object' &&
value !== null &&
'approvalId' in value &&
'actionDigest' in value &&
'actorId' in value &&
'expiresAt' in value
);
}
private key(approvalId: string): string {
return `tess:command-approval:${approvalId}`;
}
}