Verifies a digital signature that was generated by the Sign operation.
kms_verify(KeyId, Message, MessageType, Signature, SigningAlgorithm,
GrantTokens)
[required] Identifies the asymmetric CMK that will be used to verify the signature. This must be the same CMK that was used to generate the signature. If you specify a different CMK, the signature verification fails.
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/"
.
To specify a CMK in a different AWS 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 CMK, use ListKeys or DescribeKey. To get the alias name and alias ARN, use ListAliases.
[required] Specifies the message that was signed, or a hash digest of that message. Messages can be 0-4096 bytes. To verify a larger message, provide a hash digest of the message.
If the digest of the message specified here is different from the message digest that was signed, the signature verification fails.
Tells AWS KMS whether the value of the Message
parameter is a message
or message digest. To indicate a message, enter RAW
. To indicate a
message digest, enter DIGEST
.
[required] The signature that the Sign
operation generated.
[required] The signing algorithm that was used to sign the message. If you submit a different algorithm, the signature verification fails.
A list of grant tokens.
For more information, see Grant Tokens in the AWS Key Management Service Developer Guide.
svc$verify( KeyId = "string", Message = raw, MessageType = "RAW"|"DIGEST", Signature = raw, SigningAlgorithm = "RSASSA_PSS_SHA_256"|"RSASSA_PSS_SHA_384"|"RSASSA_PSS_SHA_512"|"RSASSA_PKCS1_V1_5_SHA_256"|"RSASSA_PKCS1_V1_5_SHA_384"|"RSASSA_PKCS1_V1_5_SHA_512"|"ECDSA_SHA_256"|"ECDSA_SHA_384"|"ECDSA_SHA_512", GrantTokens = list( "string" ) )
Verification confirms that an authorized user signed the message with
the specified CMK and signing algorithm, and the message hasn\'t changed
since it was signed. If the signature is verified, the value of the
SignatureValid
field in the response is True
. If the signature
verification fails, the Verify
operation fails with an
KMSInvalidSignatureException
exception.
A digital signature is generated by using the private key in an asymmetric CMK. The signature is verified by using the public key in the same asymmetric CMK. For information about symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in the AWS Key Management Service Developer Guide.
To verify a digital signature, you can use the Verify
operation.
Specify the same asymmetric CMK, message, and signing algorithm that
were used to produce the signature.
You can also verify the digital signature by using the public key of the
CMK outside of AWS KMS. Use the GetPublicKey operation to download the
public key in the asymmetric CMK and then use the public key to verify
the signature outside of AWS KMS. The advantage of using the Verify
operation is that it is performed within AWS KMS. As a result, it\'s
easy to call, the operation is performed within the FIPS boundary, it is
logged in AWS CloudTrail, and you can use key policy and IAM policy to
determine who is authorized to use the CMK to verify signatures.
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.