cad1554d94
Reversible AES-256-GCM encryption for registration tokens so the install one-liner can auto-fill the token value again. Migration 049 adds token_encrypted column; token_hash kept for lookup. AgentManagement.tsx gets platform cards (Linux, Windows; macOS = soon) with generateInstallCommand for all platforms. Inert until backend lands. system_event_logger.go extracted from deleted event_stream.go — SystemEventLogger survives, unified substrate does not. security_settings_service.go and secrets_manager.go simplified.
72 lines
2.3 KiB
Go
72 lines
2.3 KiB
Go
// Package crypto is the single AES-256-GCM at-rest primitive for the RedFlag
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// server. It exists to collapse the duplicated, divergent encrypt/decrypt copies
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// that previously lived in services (one of which prepended the nonce twice and
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// could not round-trip). There is one encrypt path and one decrypt path here;
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// callers supply a raw 32-byte key and own where that key comes from.
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//
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// Wire format: nonce || ciphertext-with-tag (the nonce is prepended once). This
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// matches the format already written by the security settings service, so values
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// it produced remain decryptable through this helper.
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package crypto
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import (
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"fmt"
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"io"
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)
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// KeySize is the required key length for AES-256.
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const KeySize = 32
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// Encrypt seals plaintext with AES-256-GCM under key (which must be 32 bytes).
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// The returned slice is nonce || ciphertext; store or transmit it as-is.
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func Encrypt(key, plaintext []byte) ([]byte, error) {
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gcm, err := newGCM(key)
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if err != nil {
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return nil, err
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}
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nonce := make([]byte, gcm.NonceSize())
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if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
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return nil, fmt.Errorf("generate nonce: %w", err)
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}
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// Seal appends the ciphertext to nonce, yielding nonce||ciphertext in one
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// allocation. The nonce is prefixed exactly once.
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return gcm.Seal(nonce, nonce, plaintext, nil), nil
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}
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// Decrypt reverses Encrypt. data must be nonce || ciphertext as produced by
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// Encrypt. A failed open (wrong key, truncation, tampering) returns an error;
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// it never returns a partial or guessed plaintext.
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func Decrypt(key, data []byte) ([]byte, error) {
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gcm, err := newGCM(key)
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if err != nil {
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return nil, err
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}
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nonceSize := gcm.NonceSize()
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if len(data) < nonceSize {
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return nil, fmt.Errorf("ciphertext too short: %d bytes", len(data))
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}
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nonce, ciphertext := data[:nonceSize], data[nonceSize:]
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plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
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if err != nil {
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return nil, fmt.Errorf("decrypt: %w", err)
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}
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return plaintext, nil
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}
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func newGCM(key []byte) (cipher.AEAD, error) {
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if len(key) != KeySize {
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return nil, fmt.Errorf("invalid key size: expected %d bytes, got %d", KeySize, len(key))
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}
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, fmt.Errorf("create cipher: %w", err)
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}
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return cipher.NewGCM(block)
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}
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