Directory Service for Microsoft Active Directory allows you to configure trust relationships. For example, you can establish a trust between your Managed Microsoft AD directory, and your existing self-managed Microsoft Active Directory. This would allow you to provide users and groups access to resources in either domain, with a single set of credentials.
See https://www.paws-r-sdk.com/docs/directoryservice_create_trust/ for full documentation.
directoryservice_create_trust(
DirectoryId,
RemoteDomainName,
TrustPassword,
TrustDirection,
TrustType = NULL,
ConditionalForwarderIpAddrs = NULL,
SelectiveAuth = NULL
)[required] The Directory ID of the Managed Microsoft AD directory for which to establish the trust relationship.
[required] The Fully Qualified Domain Name (FQDN) of the external domain for which to create the trust relationship.
[required] The trust password. The must be the same password that was used when creating the trust relationship on the external domain.
[required] The direction of the trust relationship.
The trust relationship type. Forest is the default.
The IP addresses of the remote DNS server associated with RemoteDomainName.
Optional parameter to enable selective authentication for the trust.