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Custom KMS key setup for data retention service - AWS Wickr
Custom KMS key policy setup

This guide documents the new AWS Wickr administration console, released on March 13, 2025. For documentation on the classic version of the AWS Wickr administration console, see Classic Administration Guide.

Custom KMS key setup for data retention service

To use your own KMS keys with the data retention service, create keys with the following configurations before launching the product:

Retention Key

  • Key type: Symmetric (SYMMETRIC_DEFAULT)

  • Key usage: Encrypt and decrypt

  • Key rotation: Recommended to enable

Password Recovery Key

  • Key type: Asymmetric (ECC_NIST_P384)

  • Key usage: Key agreement

  • Key rotation: Not supported for asymmetric keys

Custom KMS key policy setup

  1. Create your KMS keys with the required configurations above.

  2. Copy each key's Key ID from the KMS console.

  3. Launch the data retention product in Service Catalog, entering the Key IDs into the KmsKeyId and PasswordRecoveryKeyId fields.

  4. After the stack completes, navigate to the Outputs tab.

  5. Copy the values for DRSCustomerCrossAccountRoleArn and DecryptionLambdaRoleArn.

  6. Open the KMS console and select your custom retention key.

  7. In the Key policy section, choose Switch to policy view.

  8. Choose Edit.

  9. Add the following statements into your key policy's "Statement" array, replacing the placeholder ARNs with the values from step 5.

  10. Choose Save changes.

  11. Repeat steps 6–10 for the password recovery key using the password recovery statements below.

Retention key — Statements to add

{
  "Sid": "EnclaveGenerateDataKey",
  "Effect": "Allow",
  "Principal": {
    "AWS": "{DRSCustomerCrossAccountRoleArn}"
  },
  "Action": "kms:GenerateDataKey",
  "Resource": "*",
  "Condition": {
    "StringLike": {
      "kms:RecipientAttestation:PCR0": "*",
      "kms:RecipientAttestation:PCR1": "*",
      "kms:RecipientAttestation:PCR2": "*"
    },
    "ForAnyValue:StringEquals": {
      "kms:EncryptionContextKeys": [
        "aws:wickr:network:id",
        "aws:wickr:app:id"
      ]
    }
  }
},
{
  "Sid": "EnclaveDescribeKey",
  "Effect": "Allow",
  "Principal": {
    "AWS": "{DRSCustomerCrossAccountRoleArn}"
  },
  "Action": "kms:DescribeKey",
  "Resource": "*"
},
{
  "Sid": "EnclaveDecryptWithAttestation",
  "Effect": "Allow",
  "Principal": {
    "AWS": "{DRSCustomerCrossAccountRoleArn}"
  },
  "Action": "kms:Decrypt",
  "Resource": "*",
  "Condition": {
    "StringLike": {
      "kms:RecipientAttestation:PCR0": "*",
      "kms:RecipientAttestation:PCR1": "*",
      "kms:RecipientAttestation:PCR2": "*"
    },
    "ForAnyValue:StringEquals": {
      "kms:EncryptionContextKeys": "aws:wickr:app:id"
    }
  }
},
{
  "Sid": "DecryptLambdaDecrypt",
  "Effect": "Allow",
  "Principal": {
    "AWS": "{DecryptionLambdaRoleArn}"
  },
  "Action": "kms:Decrypt",
  "Resource": "*",
  "Condition": {
    "ForAnyValue:StringEquals": {
      "kms:EncryptionContextKeys": "aws:wickr:network:id"
    }
  }
}

Purpose of each statement can be found at Encryption at rest under the section Configuring permissions to use a customer managed KMS key.

Password recovery key — Statements to add

{
  "Sid": "EnclaveDeriveSharedSecret",
  "Effect": "Allow",
  "Principal": {
    "AWS": "{DRSCustomerCrossAccountRoleArn}"
  },
  "Action": "kms:DeriveSharedSecret",
  "Resource": "*",
  "Condition": {
    "StringLike": {
      "kms:RecipientAttestation:PCR0": "*",
      "kms:RecipientAttestation:PCR1": "*",
      "kms:RecipientAttestation:PCR2": "*"
    }
  }
},
{
  "Sid": "CustomerGetPublicKey",
  "Effect": "Allow",
  "Principal": {
    "AWS": "{DRSCustomerCrossAccountRoleArn}"
  },
  "Action": [
    "kms:DescribeKey",
    "kms:GetPublicKey"
  ],
  "Resource": "*"
}

Purpose of each statement:

EnclaveDeriveSharedSecret

  • kms:DeriveSharedSecret — Invoked by the Nitro Enclave to perform ECDH key agreement using the password recovery key's private key. This derives a shared secret that is used to decrypt the customer's password during the migration workflow. Only permitted when a valid Nitro Enclave attestation document is provided (PCR0/1/2 conditions), ensuring the key agreement cannot occur outside the enclave.

CustomerGetPublicKey

  • kms:GetPublicKey — Allows retrieval of the password recovery key's ECC P-384 public key. This is used by thepassword collection script running on the customer's machine to perform local ECDH encryption of the password.

  • kms:DescribeKey — Allows retrieval of key metadata (key spec, usage, status) for validation.

Example — Retention key

Before:

{
  "Version": "2012-10-17", 
  "Statement": [
    {
      "Sid": "YourExistingStatements",
      "Effect": "...",
      "...": "..."
    }
  ]
}

After:

{
  "Version": "2012-10-17", 
  "Statement": [
    {
      "Sid": "YourExistingStatements",
      "Effect": "...",
      "...": "..."
     },
    {
      "Sid": "EnclaveGenerateDataKey",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::{account-id}:role/DRSCustomerCrossAccountRole-{network-id}-{region}"
      },
      "Action": "kms:GenerateDataKey",
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "kms:RecipientAttestation:PCR0": "*",
          "kms:RecipientAttestation:PCR1": "*",
          "kms:RecipientAttestation:PCR2": "*"
        },
        "ForAnyValue:StringEquals": {
          "kms:EncryptionContextKeys": [
            "aws:wickr:network:id",
            "aws:wickr:app:id"
          ]
        }
      }
    },
    {
      "Sid": "EnclaveDescribeKey",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::{account-id}:role/DRSCustomerCrossAccountRole-{network-id}-{region}"
      },
      "Action": "kms:DescribeKey",
      "Resource": "*"
    },
    {
      "Sid": "EnclaveDecryptWithAttestation",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::{account-id}:role/DRSCustomerCrossAccountRole-{network-id}-{region}"
      },
      "Action": "kms:Decrypt",
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "kms:RecipientAttestation:PCR0": "*",
          "kms:RecipientAttestation:PCR1": "*",
          "kms:RecipientAttestation:PCR2": "*"
        },
        "ForAnyValue:StringEquals": {
          "kms:EncryptionContextKeys": "aws:wickr:app:id"
        }
      }
    },
    {
      "Sid": "DecryptLambdaDecrypt",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::{account-id}:role/{DecryptionLambdaRoleName}"
      },
      "Action": "kms:Decrypt",
      "Resource": "*",
      "Condition": {
        "ForAnyValue:StringEquals": {
          "kms:EncryptionContextKeys": "aws:wickr:network:id"
        }
      }
    }
  ]
}