Skip to content

Marshaling normalization for HMAC comparison #1141

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Marshaling normalization for HMAC comparison #1141

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 14 additions & 2 deletions helpers/hmac.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -46,7 +46,7 @@ func HandleSecretHMAC(ctx context.Context, client ctrlclient.Client,

// HMAC the Vault secret data so that it can be compared to the what's in the
// destination Secret.
message, err := json.Marshal(data)
message, err := marshalSecretDataForHMAC(data)
if err != nil {
return false, nil, err
}
Expand Down Expand Up @@ -109,7 +109,8 @@ func HMACDestinationSecret(ctx context.Context, client ctrlclient.Client,
// out-of-band change made to the Secret's data in this case the controller
// should do the sync.
if cur, ok, err := GetSyncableSecret(ctx, client, obj); ok {
curMessage, err := json.Marshal(cur.Data)

curMessage, err := marshalSecretDataForHMAC(cur.Data)
if err != nil {
return false, err
}
Expand Down Expand Up @@ -345,6 +346,17 @@ func MACMessage(key, data []byte) ([]byte, error) {
return mac.Sum(nil), nil
}

// marshalSecretDataForHMAC normalizes marshalling ensuring that for HMAC
// comparison an empty Kubernetes secret (nil) produces the same JSON representation
// as a Vault empty secret (map[string][]byte{}{}).
func marshalSecretDataForHMAC(data map[string][]byte) ([]byte, error) {
// Normalize nil to empty map to ensure consistent JSON marshaling
if data == nil {
data = make(map[string][]byte)
}
return json.Marshal(data)
}

// generateHMACKey for computing HMACs. The key size is 128 bit.
func generateHMACKey() ([]byte, error) {
key := make([]byte, hmacKeyLength)
Expand Down
Loading