#Encryption

#Introduction

Sensitive business data, such as customer phone numbers, email addresses, and card numbers, can be encrypted and stored in the database as ciphertext.

#Encryption method

#How it works

The plugin uses envelope encryption.

#Key creation flow

1. When you create an encrypted field for the first time, the system generates a 32-byte application key and saves it, Base64 encoded, in the default storage directory.
2. When you create an encrypted field, the system generates a random 32-byte field key. It encrypts this key with the application key and a randomly generated 16-byte field initialization vector using AES, then saves it in the options field of the fields table.

#Field encryption flow

1. When data is written to an encrypted field, the system reads the encrypted field key and field initialization vector from the options field of the fields table.
2. It decrypts the encrypted field key with the application key and field initialization vector, then encrypts the data with the field key and a randomly generated 16-byte data initialization vector using AES.
3. It signs the data with the decrypted field key using HMAC-SHA256, then Base64 encodes the result. This data signature is used for data lookup.
4. It concatenates the 16-byte data initialization vector and encrypted data ciphertext as binary data, then Base64 encodes the result.
5. It joins the Base64 data signature and Base64 data ciphertext with ..
6. It saves the final concatenated string in the database.

#Environment variable

To specify an application key, use the ENCRYPTION_FIELD_KEY_PATH environment variable. The plugin loads the file at this path as the application key.

Application-key file requirements:

1. The file extension must be .key.
2. The file name is used as the key ID. Use a UUID to keep it unique.
3. The file content must be Base64-encoded 32-byte binary data.

ENCRYPTION_FIELD_KEY_PATH=/path/to/my/app-keys/270263524860909922913.key

#Field configuration

#Effect on filtering

Encrypted fields support only equals, does not equal, exists, and does not exist filters.

Data is filtered as follows:

1. Read the field key for the encrypted field and decrypt it with the application key.
2. Sign the user-entered lookup text with the field key using HMAC-SHA256.
3. Append . to the signed lookup text and perform a prefix-match lookup against the encrypted database value.

#Key rotation

After an application is migrated to a new environment, use nocobase key-rotation when you do not want to continue using the old environment's application key.

Key rotation requires the old application's application key. The command generates a new application key, replaces the old key, and saves the new key Base64 encoded in the default storage directory.

# --key-path specifies the old application-key file corresponding to encrypted database data
yarn nocobase key-rotation --key-path /path/to/old-app-keys/270263524860909922913.key

To replace a sub-application application key, add --app-name and specify the sub-application name.

yarn nocobase key-rotation --app-name a_w0r211vv0az --key-path /path/to/old-app-keys/270263524860909922913.key