GenerateDataKeyPair - GenerateDataKeyWithoutPlaintext - GenerateDataKeyPairWithoutPlaintext You can use this operation to decrypt ciphertext that was encrypted under a symmetric or asymmetric CMK
Decrypts ciphertext that was encrypted by a AWS KMS customer master key (CMK) using any of the following operations:
kms_decrypt(CiphertextBlob, EncryptionContext, GrantTokens, KeyId,
EncryptionAlgorithm)[required] Ciphertext to be decrypted. The blob includes metadata.
Specifies the encryption context to use when decrypting the data. An encryption context is valid only for cryptographic operations with a symmetric CMK. The standard asymmetric encryption algorithms that AWS KMS uses do not support an encryption context.
An encryption context is a collection of non-secret key-value pairs that represents 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 optional when encrypting with a symmetric CMK, but it is highly recommended.
For more information, see Encryption Context in the AWS Key Management Service Developer Guide.
A list of grant tokens.
For more information, see Grant Tokens in the AWS Key Management Service Developer Guide.
Specifies the customer master key (CMK) that AWS KMS will use to decrypt the ciphertext. Enter a key ID of the CMK that was used to encrypt the ciphertext.
If you specify a KeyId value, the Decrypt operation succeeds only if
the specified CMK was used to encrypt the ciphertext.
This parameter is required only when the ciphertext was encrypted under an asymmetric CMK. Otherwise, AWS KMS uses the metadata that it adds to the ciphertext blob to determine which CMK was used to encrypt the ciphertext. However, you can use this parameter to ensure that a particular CMK (of any kind) is used to decrypt the ciphertext.
To specify a CMK, use its key ID, Amazon Resource Name (ARN), alias
name, or alias ARN. When using an alias name, prefix it with "alias/".
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 CMK, use ListKeys or DescribeKey. To get the alias name and alias ARN, use ListAliases.
Specifies the encryption algorithm that will be used to decrypt the
ciphertext. Specify the same algorithm that was used to encrypt the
data. If you specify a different algorithm, the Decrypt operation
fails.
This parameter is required only when the ciphertext was encrypted under
an asymmetric CMK. The default value, SYMMETRIC_DEFAULT, represents
the only supported algorithm that is valid for symmetric CMKs.
svc$decrypt(
CiphertextBlob = raw,
EncryptionContext = list(
"string"
),
GrantTokens = list(
"string"
),
KeyId = "string",
EncryptionAlgorithm = "SYMMETRIC_DEFAULT"|"RSAES_OAEP_SHA_1"|"RSAES_OAEP_SHA_256"
)
Encrypt
GenerateDataKey
GenerateDataKeyPair
GenerateDataKeyWithoutPlaintext
GenerateDataKeyPairWithoutPlaintext
You can use this operation to decrypt ciphertext that was encrypted under a symmetric or asymmetric CMK. When the CMK is asymmetric, you must specify the CMK and the encryption algorithm that was used to encrypt the ciphertext. For information about symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in the AWS Key Management Service Developer Guide.
The Decrypt operation also decrypts ciphertext that was encrypted outside of AWS KMS by the public key in an AWS KMS asymmetric CMK. However, it cannot decrypt ciphertext produced by other libraries, such as the AWS Encryption SDK or Amazon S3 client-side encryption. These libraries return a ciphertext format that is incompatible with AWS KMS.
If the ciphertext was encrypted under a symmetric CMK, you do not need
to specify the CMK or the encryption algorithm. AWS KMS can get this
information from metadata that it adds to the symmetric ciphertext blob.
However, if you prefer, you can specify the KeyId to ensure that a
particular CMK is used to decrypt the ciphertext. If you specify a
different CMK than the one used to encrypt the ciphertext, the Decrypt
operation fails.
Whenever possible, use key policies to give users permission to call the
Decrypt operation on a particular CMK, instead of using IAM policies.
Otherwise, you might create an IAM user policy that gives the user
Decrypt permission on all CMKs. This user could decrypt ciphertext that
was encrypted by CMKs in other accounts if the key policy for the
cross-account CMK permits it. If you must use an IAM policy for
Decrypt permissions, limit the user to particular CMKs or particular
trusted accounts.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
# NOT RUN {
# The following example decrypts data that was encrypted with a customer
# master key (CMK) in AWS KMS.
svc$decrypt(
CiphertextBlob = "<binary data>"
)
# }
# NOT RUN {
# }
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