[ aws . kms ]

encrypt

Description

Encrypts plaintext of up to 4,096 bytes using a KMS key. You can use a symmetric or asymmetric KMS key with a KeyUsage of ENCRYPT_DECRYPT .

You can use this operation to encrypt small amounts of arbitrary data, such as a personal identifier or database password, or other sensitive information. You don’t need to use the Encrypt operation to encrypt a data key. The GenerateDataKey and GenerateDataKeyPair operations return a plaintext data key and an encrypted copy of that data key.

If you use a symmetric encryption KMS key, you can use an encryption context to add additional security to your encryption operation. If you specify an EncryptionContext when encrypting data, you must specify the same encryption context (a case-sensitive exact match) when decrypting the data. Otherwise, the request to decrypt fails with an InvalidCiphertextException . For more information, see Encryption Context in the Key Management Service Developer Guide .

If you specify an asymmetric KMS key, you must also specify the encryption algorithm. The algorithm must be compatible with the KMS key spec.

Warning

When you use an asymmetric KMS key to encrypt or reencrypt data, be sure to record the KMS key and encryption algorithm that you choose. You will be required to provide the same KMS key and encryption algorithm when you decrypt the data. If the KMS key and algorithm do not match the values used to encrypt the data, the decrypt operation fails.

You are not required to supply the key ID and encryption algorithm when you decrypt with symmetric encryption KMS keys because KMS stores this information in the ciphertext blob. KMS cannot store metadata in ciphertext generated with asymmetric keys. The standard format for asymmetric key ciphertext does not include configurable fields.

The maximum size of the data that you can encrypt varies with the type of KMS key and the encryption algorithm that you choose.

  • Symmetric encryption KMS keys
    • SYMMETRIC_DEFAULT : 4096 bytes
  • RSA_2048
    • RSAES_OAEP_SHA_1 : 214 bytes
    • RSAES_OAEP_SHA_256 : 190 bytes
  • RSA_3072
    • RSAES_OAEP_SHA_1 : 342 bytes
    • RSAES_OAEP_SHA_256 : 318 bytes
  • RSA_4096
    • RSAES_OAEP_SHA_1 : 470 bytes
    • RSAES_OAEP_SHA_256 : 446 bytes
  • SM2PKE : 1024 bytes (China Regions only)

The KMS key that you use for this operation must be in a compatible key state. For details, see Key states of KMS keys in the Key Management Service Developer Guide .

Cross-account use : Yes. To perform this operation with a KMS key in a different Amazon Web Services account, specify the key ARN or alias ARN in the value of the KeyId parameter.

Required permissions : kms:Encrypt (key policy)

Related operations:

  • Decrypt
  • GenerateDataKey
  • GenerateDataKeyPair
Eventual consistency : The KMS API follows an eventual consistency model. For more information, see KMS eventual consistency .

See also: AWS API Documentation

Synopsis

  encrypt
--key-id <value>
--plaintext <value>
[--encryption-context <value>]
[--grant-tokens <value>]
[--encryption-algorithm <value>]
[--dry-run | --no-dry-run]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]
[--debug]
[--endpoint-url <value>]
[--no-verify-ssl]
[--no-paginate]
[--output <value>]
[--query <value>]
[--profile <value>]
[--region <value>]
[--version <value>]
[--color <value>]
[--no-sign-request]
[--ca-bundle <value>]
[--cli-read-timeout <value>]
[--cli-connect-timeout <value>]
[--cli-binary-format <value>]
[--no-cli-pager]
[--cli-auto-prompt]
[--no-cli-auto-prompt]

Options

--key-id (string)

Identifies the KMS key to use in the encryption operation. The KMS key must have a KeyUsage of ENCRYPT_DECRYPT . To find the KeyUsage of a KMS key, use the DescribeKey operation.

To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN. When using an alias name, prefix it with "alias/" . To specify a KMS key in a different Amazon Web Services account, you must use the key ARN or alias ARN.

For example:

  • Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab
  • Key ARN: arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab
  • Alias name: alias/ExampleAlias
  • Alias ARN: arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias

To get the key ID and key ARN for a KMS key, use ListKeys or DescribeKey . To get the alias name and alias ARN, use ListAliases .

--plaintext (blob)

Data to be encrypted.

--encryption-context (map)

Specifies the encryption context that will be used to encrypt the data. An encryption context is valid only for cryptographic operations with a symmetric encryption KMS key. The standard asymmetric encryption algorithms and HMAC algorithms that KMS uses do not support an encryption context.

Warning

Do not include confidential or sensitive information in this field. This field may be displayed in plaintext in CloudTrail logs and other output.

An encryption context is a collection of non-secret key-value pairs that represent additional authenticated data. When you use an encryption context to encrypt data, you must specify the same (an exact case-sensitive match) encryption context to decrypt the data. An encryption context is supported only on operations with symmetric encryption KMS keys. On operations with symmetric encryption KMS keys, an encryption context is optional, but it is strongly recommended.

For more information, see Encryption context in the Key Management Service Developer Guide .

key -> (string)

value -> (string)

Shorthand Syntax:

KeyName1=string,KeyName2=string

JSON Syntax:

{"string": "string"
  ...}

--grant-tokens (list)

A list of grant tokens.

Use a grant token when your permission to call this operation comes from a new grant that has not yet achieved eventual consistency . For more information, see Grant token and Using a grant token in the Key Management Service Developer Guide .

(string)

Syntax:

"string" "string" ...

--encryption-algorithm (string)

Specifies the encryption algorithm that KMS will use to encrypt the plaintext message. The algorithm must be compatible with the KMS key that you specify.

This parameter is required only for asymmetric KMS keys. The default value, SYMMETRIC_DEFAULT , is the algorithm used for symmetric encryption KMS keys. If you are using an asymmetric KMS key, we recommend RSAES_OAEP_SHA_256.

The SM2PKE algorithm is only available in China Regions.

Possible values:

  • SYMMETRIC_DEFAULT
  • RSAES_OAEP_SHA_1
  • RSAES_OAEP_SHA_256
  • SM2PKE

--dry-run | --no-dry-run (boolean)

Checks if your request will succeed. DryRun is an optional parameter.

To learn more about how to use this parameter, see Testing your KMS API calls in the Key Management Service Developer Guide .

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command. The generated JSON skeleton is not stable between versions of the AWS CLI and there are no backwards compatibility guarantees in the JSON skeleton generated.

Global Options

--debug (boolean)

Turn on debug logging.

--endpoint-url (string)

Override command’s default URL with the given URL.

--no-verify-ssl (boolean)

By default, the AWS CLI uses SSL when communicating with AWS services. For each SSL connection, the AWS CLI will verify SSL certificates. This option overrides the default behavior of verifying SSL certificates.

--no-paginate (boolean)

Disable automatic pagination. If automatic pagination is disabled, the AWS CLI will only make one call, for the first page of results.

--output (string)

The formatting style for command output.

  • json
  • text
  • table
  • yaml
  • yaml-stream

--query (string)

A JMESPath query to use in filtering the response data.

--profile (string)

Use a specific profile from your credential file.

--region (string)

The region to use. Overrides config/env settings.

--version (string)

Display the version of this tool.

--color (string)

Turn on/off color output.

  • on
  • off
  • auto

--no-sign-request (boolean)

Do not sign requests. Credentials will not be loaded if this argument is provided.

--ca-bundle (string)

The CA certificate bundle to use when verifying SSL certificates. Overrides config/env settings.

--cli-read-timeout (int)

The maximum socket read time in seconds. If the value is set to 0, the socket read will be blocking and not timeout. The default value is 60 seconds.

--cli-connect-timeout (int)

The maximum socket connect time in seconds. If the value is set to 0, the socket connect will be blocking and not timeout. The default value is 60 seconds.

--cli-binary-format (string)

The formatting style to be used for binary blobs. The default format is base64. The base64 format expects binary blobs to be provided as a base64 encoded string. The raw-in-base64-out format preserves compatibility with AWS CLI V1 behavior and binary values must be passed literally. When providing contents from a file that map to a binary blob fileb:// will always be treated as binary and use the file contents directly regardless of the cli-binary-format setting. When using file:// the file contents will need to properly formatted for the configured cli-binary-format.

  • base64
  • raw-in-base64-out

--no-cli-pager (boolean)

Disable cli pager for output.

--cli-auto-prompt (boolean)

Automatically prompt for CLI input parameters.

--no-cli-auto-prompt (boolean)

Disable automatically prompt for CLI input parameters.

Examples

Note

To use the following examples, you must have the AWS CLI installed and configured. See the Getting started guide in the AWS CLI User Guide for more information.

Unless otherwise stated, all examples have unix-like quotation rules. These examples will need to be adapted to your terminal’s quoting rules. See Using quotation marks with strings in the AWS CLI User Guide .

Example 1: To encrypt the contents of a file on Linux or MacOS

The following encrypt command demonstrates the recommended way to encrypt data with the AWS CLI.

aws kms encrypt \
    --key-id 1234abcd-12ab-34cd-56ef-1234567890ab \
    --plaintext fileb://ExamplePlaintextFile \
    --output text \
    --query CiphertextBlob | base64 \
    --decode > ExampleEncryptedFile

The command does several things:

  1. Uses the --plaintext parameter to indicate the data to encrypt. This parameter value must be base64-encoded.

    The value of the plaintext parameter must be base64-encoded, or you must use the fileb:// prefix, which tells the AWS CLI to read binary data from the file.

    If the file is not in the current directory, type the full path to file. For example: fileb:///var/tmp/ExamplePlaintextFile or fileb://C:\Temp\ExamplePlaintextFile. For more information about reading AWS CLI parameter values from a file, see Loading Parameters from a File in the AWS Command Line Interface User Guide and Best Practices for Local File Parameters on the AWS Command Line Tool Blog.

  2. Uses the --output and --query parameters to control the command’s output.

    These parameters extract the encrypted data, called the ciphertext, from the command’s output.

    For more information about controlling output, see Controlling Command Output in the AWS Command Line Interface User Guide.

  3. Uses the base64 utility to decode the extracted output into binary data.

    The ciphertext that is returned by a successful encrypt command is base64-encoded text. You must decode this text before you can use the AWS CLI to decrypt it.

  4. Saves the binary ciphertext to a file.

    The final part of the command (> ExampleEncryptedFile) saves the binary ciphertext to a file to make decryption easier. For an example command that uses the AWS CLI to decrypt data, see the decrypt examples.

Example 2: Using the AWS CLI to encrypt data on Windows

This example is the same as the previous one, except that it uses the certutil tool instead of base64. This procedure requires two commands, as shown in the following example.

aws kms encrypt \
    --key-id 1234abcd-12ab-34cd-56ef-1234567890ab \
    --plaintext fileb://ExamplePlaintextFile \
    --output text \
    --query CiphertextBlob > C:\Temp\ExampleEncryptedFile.base64

certutil -decode C:\Temp\ExampleEncryptedFile.base64 C:\Temp\ExampleEncryptedFile

Example 3: Encrypting with an asymmetric KMS key

The following encrypt command shows how to encrypt plaintext with an asymmetric KMS key. The --encryption-algorithm parameter is required. As in all encrypt CLI commands, the plaintext parameter must be base64-encoded, or you must use the fileb:// prefix, which tells the AWS CLI to read binary data from the file.

aws kms encrypt \
    --key-id 1234abcd-12ab-34cd-56ef-1234567890ab \
    --encryption-algorithm RSAES_OAEP_SHA_256 \
    --plaintext fileb://ExamplePlaintextFile \
    --output text \
    --query CiphertextBlob | base64 \
    --decode > ExampleEncryptedFile

This command produces no output.

Output

CiphertextBlob -> (blob)

The encrypted plaintext. When you use the HTTP API or the Amazon Web Services CLI, the value is Base64-encoded. Otherwise, it is not Base64-encoded.

KeyId -> (string)

The Amazon Resource Name (key ARN ) of the KMS key that was used to encrypt the plaintext.

EncryptionAlgorithm -> (string)

The encryption algorithm that was used to encrypt the plaintext.