ClientEncryption.decrypt()

Behavior

Read operations issued from a database connection configured with access to the correct Key Management Service (KMS) and Key Vault can automatically decrypt field values encrypted using ClientEncryption.encrypt(). Clients only need to use decrypt() to decrypt Binary subtype 6 values not stored within a document field.

Example

The following example uses a locally managed KMS for the client-side field level encryption configuration.

To configure client-side field level encryption for a locally managed key:

• generate a base64-encoded 96-byte string with no line breaks

• use mongosh to load the key

export TEST_LOCAL_KEY=$(echo "$(head -c 96 /dev/urandom | base64 | tr -d '\n')")

mongosh --nodb

Create the client-side field level encryption object using the generated local key string:

 var autoEncryptionOpts = {
   "keyVaultNamespace" : "encryption.__dataKeys",
   "kmsProviders" : {
     "local" : {
       "key" : BinData(0, process.env["TEST_LOCAL_KEY"])
     }
   }
 }

Use the Mongo() constructor with the client-side field level encryption options configured to create a database connection. Replace the mongodb://myMongo.example.net URI with the connection string URI of the target cluster.

encryptedClient = Mongo(
  "mongodb://myMongo.example.net:27017/?replSetName=myMongo",
   autoEncryptionOpts
)

Retrieve the ClientEncryption object and use the ClientEncryption.decrypt() method to decrypt a value encrypted by ClientEncryption.encrypt().

clientEncryption = encryptedClient.getClientEncryption();

clientEncryption.decrypt(BinData(6,"AmTi2H3xaEk8u9+jlFNaLLkC3Q/+kmwDbbWrq+h9nuv9W+u7A5a0UnpULBNZH+Q21fAztPpU09wpKPrju9dKfpN1Afpj1/ZhFcH6LYZOWSBBOAuUNjPLxMNSYOOuITuuYWo="))

If successful, decrypt() returns the decrypted value:

"123-45-6789"

For complete documentation on initiating MongoDB connections with client-side field level encryption enabled, see Mongo().