Files
felhom-agent/internal/authz/blob.go
T
admin 588fed2aa9 slice 10B: operator-signed destructive completion (offline key + signing CLI) (v0.16.0)
A destructive op runs ONLY on a pinned-key-verified, nonce-fresh, in-window,
host-bound, durable-id-bound operator signature. New cmd/felhom-opsign signs
canonical OpBlobs offline via ssh-keygen -Y sign (hardware-ready); the signing
key is never in the hub or agent. New internal/signedjobs runner verifies each
queued blob through the gate and only on all-pass runs the WipeExecutor, which
re-resolves the DURABLE device id + re-inspects (8C) before mkfs — closing the
8C data-bearing-wipe pending_signature gap. New storage durable-device
resolution; authz.CanonicalBlob promoted to production. Real-crypto tests assert
valid executes and forged/replay/expired/retarget/non-pinned are rejected
(executor never called).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-10 20:14:16 +02:00

82 lines
3.4 KiB
Go

package authz
import (
"encoding/json"
"fmt"
"strings"
"time"
)
// CanonicalBlob builds the canonical OpBlob bytes (phase4 §2 field order: keys sorted at
// every level, no insignificant whitespace, no trailing newline, UTF-8). This is the SINGLE
// production source of the signed bytes — the operator signing CLI (cmd/felhom-opsign) and the
// in-Go test minting both call it, so the signer can NEVER drift from what the verifier expects
// (the verifier authenticates over the RAW received bytes, so these bytes ARE the contract).
//
// params is canonicalized internally (parsed + re-marshaled → object keys sorted, whitespace
// stripped) so the same op+params always yields identical bytes; "" → "{}". Returns an error
// only when params is not valid JSON.
func CanonicalBlob(op, hostID, guestID, keyID, nonce, paramsJSON string, issued, expires time.Time) ([]byte, error) {
params := strings.TrimSpace(paramsJSON)
if params == "" {
params = "{}"
}
var pv interface{}
if err := json.Unmarshal([]byte(params), &pv); err != nil {
return nil, fmt.Errorf("authz: params is not valid JSON: %w", err)
}
pc, err := json.Marshal(pv) // Go marshals object keys sorted, compact
if err != nil {
return nil, fmt.Errorf("authz: canonicalizing params: %w", err)
}
return []byte(fmt.Sprintf(
`{"expires_at":%q,"issued_at":%q,"key_id":%q,"nonce":%q,"op":%q,"params":%s,"target":{"guest_id":%q,"host_id":%q}}`,
expires.UTC().Format(time.RFC3339), issued.UTC().Format(time.RFC3339),
keyID, nonce, op, pc, guestID, hostID)), nil
}
// Target binds an op to a specific box (and optionally a guest) — the anti-retarget
// field. The §7 reference omitted the json tags; production needs them so the
// signed canonical bytes decode correctly.
type Target struct {
HostID string `json:"host_id"`
GuestID string `json:"guest_id"`
}
// OpBlob is the canonical signed object (phase4 §2). The signature covers the
// EXACT bytes of this object's canonical JSON (keys sorted at every level, no
// insignificant whitespace, no trailing newline, UTF-8) — produced by the
// operator CLI / hub, verified here over the raw received bytes.
type OpBlob struct {
Op string `json:"op"`
Target Target `json:"target"`
Params json.RawMessage `json:"params"`
Nonce string `json:"nonce"`
IssuedAt time.Time `json:"issued_at"`
ExpiresAt time.Time `json:"expires_at"`
KeyID string `json:"key_id"`
}
// VerifiedOp is the authenticated, parsed op returned on success — everything the
// reconcile layer (slice 4) needs to route and execute, not just the op string.
type VerifiedOp struct {
Op string // the operation, e.g. "guest_destroy"
HostID string // target host (== this agent's host)
// GuestID is non-empty for a guest-scoped op; the caller routes by it. "" =
// host-scoped op. The verifier does NOT need to know all guest ids.
GuestID string
Params json.RawMessage
Nonce string
IssuedAt time.Time
ExpiresAt time.Time
// KeyID is the blob's self-declared key id — ADVISORY / audit only, never an
// authz input. Authz is the key-material allow-list match (Signer below).
KeyID string
// Signer is the allow-listed key whose material matched the signature.
Signer AllowedSigner
// KeyIDMatchesSigner is false when the blob's advisory KeyID disagrees with
// the matched signer's id (a benign audit signal, not a rejection).
KeyIDMatchesSigner bool
}