Constructor SealedValue

Namespace

MailFathom.Infrastructure.DataEncryption

Assembly

MailFathom.Infrastructure.dll

SealedValue(string, ReadOnlyMemory<byte>)

A value as it is stored: the ciphertext, and the identifier of the key that sealed it.

public SealedValue(string KeyId, ReadOnlyMemory<byte> Ciphertext)

Parameters

KeyId string

The key the value was sealed under, stored beside it.

Ciphertext ReadOnlyMemory<byte>

The sealed bytes, in the layout AesGcmEnvelope fixes.

Remarks

Storing the key identifier beside the ciphertext is what makes rotation possible at all. Without it, replacing a key would be a flag day with the service stopped, because nothing could tell which of two keys opens a given row. With it, two keys coexist, a value is re-sealed under the active key the next time it is written, and a key is retired once nothing references it.

The identifier is not a secret and is not authentication on its own: it is authenticated into the ciphertext through the binding, so rewriting it in the database makes the value fail to open rather than making it open under another key.