Security Model

# Pseudocode — actual implementation is in the repository abstraction layer
conn.execute("SELECT set_config('app.current_workspace', %s, true)", [workspace_id])

ALTER TABLE issues ENABLE ROW LEVEL SECURITY;
ALTER TABLE issues FORCE  ROW LEVEL SECURITY;

CREATE POLICY tenant_select ON issues FOR SELECT
    USING (workspace_id = app_current_tenant());

CREATE POLICY tenant_insert ON issues FOR INSERT
    WITH CHECK (workspace_id = app_current_tenant());

CREATE POLICY tenant_update ON issues FOR UPDATE
    USING (workspace_id = app_current_tenant())
    WITH CHECK (workspace_id = app_current_tenant());

CREATE POLICY tenant_delete ON issues FOR DELETE
    USING (workspace_id = app_current_tenant());

CAUSELOOP_MASTER_KEY (KEK)
  └── wraps → per-workspace Data Encryption Key (DEK)
                stored encrypted in workspace_keys table
                  └── encrypts → secret columns
                                 (config_encrypted, secret_encrypted, ...)

# AES-256-GCM envelope encryption
VERSION = 1

def encrypt(database_url: str, workspace_id: str, plaintext: bytes) -> bytes:
    dek = _dek(database_url, workspace_id)          # fetch+unwrap or generate DEK
    nonce = os.urandom(12)
    ct = AESGCM(dek).encrypt(nonce, plaintext, workspace_id.encode())  # AAD = workspace_id
    return struct.pack("B", VERSION) + nonce + ct

def decrypt(database_url: str, workspace_id: str, blob: bytes) -> bytes:
    dek = _dek(database_url, workspace_id)
    nonce, ct = blob[1:13], blob[13:]
    return AESGCM(dek).decrypt(nonce, ct, workspace_id.encode())

# Sender-side signature computation
import hashlib, hmac

def compute_signature(raw_body: bytes, secret: str) -> str:
    return hmac.new(
        secret.encode("utf-8"),
        raw_body,
        hashlib.sha256,
    ).hexdigest()

audit_log (
    id, workspace_id, actor_id, actor_name,
    action, action_category,
    target_type, target_id,
    before JSONB, after JSONB,
    ip_address, trace_id,
    created_at TIMESTAMPTZ
)