Phase 1 - Unprov plugin interfaces specification:
At this stage, we finish implementing the following generic ID mapping interfaces, which are called by LSASS batching machinery. We have our alias mechanism when we enable defining "ENABLE_ALIAS_TO_BE_SAMACCOUNT_NAME" (by default, it is NOTenabled). The alias mechanism in unprovisioned mode uses object's samAccountName as aiase.

#if 0
#define ENABLE_ALIAS_TO_BE_SAMACCOUNT_NAME
#endif

DWORD
ADUnprovPlugin_Initialize(
    VOID
    );

VOID
ADUnprovPlugin_Cleanup(
    VOID
    );

BOOLEAN
ADUnprovPlugin_SupportsAliases(
    VOID
    );

DWORD
ADUnprovPlugin_QueryByReal(
    IN BOOLEAN bIsUser,
    IN PCSTR pszNT4Name,
    IN PCSTR pszSID,
    OUT OPTIONAL PSTR* ppszAlias,
    OUT PDWORD pdwId
    );

DWORD
ADUnprovPlugin_QueryByAlias(
    IN BOOLEAN bIsUser,
    IN PCSTR pszAlias,
    OUT PSTR* ppszSid,
    OUT PDWORD pdwId
    );

DWORD
ADUnprovPlugin_QueryById(
    IN BOOLEAN bIsUser,
    IN DWORD dwId,
    OUT PSTR* ppszSid,
    OUT PSTR* ppszAlias
    );

Phase 2 - LSASS will be modified to support a plugable unprovisioned mode plugin
architecture which allows the task of mapping SIDs to uids and gids to be
delegated to a third-party plugin.  The plugin will be configured in
lsass.conf in a manner similar to existing providers:

[unprovisioned-mode-plugin:NAME]
    path = /path/to/plugin/file.so
    option1 = value1
    option2 = value2
    ...

The main entry module entry point will mirror that of LSASS provider
plugins:

DWORD
LsaInitializeUnprovisionedModePlugin(
    IN PCSTR pszName,
    IN PCSTR pszConfigFilePath,
    OUT PLSA_UNPROVISIONED_MODE_PLUGIN_FUNCTION_TABLE* ppFunctionTable
    );

This function will return a function table of the following type:

typedef struct _LSA_UNPROVISIONED_MODE_PLUGIN_FUNCTION_TABLE {
    DWORD (*pfnQueryNameSidToAliasId) (
        IN BOOLEAN bIsUser,
        IN PCSTR pszNT4Name,
        IN PCSTR pszSid,
        OUT OPTIONAL PSTR* ppszAlias,
        OUT PDWORD* pdwId
        );

    DWORD (*pfnQueryAliasToSidId) (
        IN BOOLEAN bIsUser,
        IN PCSTR pszAias,
        OUT PSTR* ppszSid,
        OUT PDWORD* pdwId
        );

     DWORD (*pfnQueryIdToSidAlias) (
        IN BOOLEAN bIsUser,
        IN DWORD dwId,
        OUT PSTR* ppszSid,
        OUT PSTR* ppszAlias
        );


#if 0
    /* Map a sid representing a user to a uid */
    DWORD (*pfnQuerySidtoUid) (
        IN PCSTR pszNT4Name,
        IN PCSTR pSid,
        OUT gid_t* pUid
        );
    /* Map a sid representing a group to a gid */
    DWORD (*pfnQuerySidtoGid) (
        IN PCSTR pszNT4Name,
        IN PCSTR pSid,
        OUT gid_t* pGid
        );
    /* Create a sid to uid mapping */
    DWORD (*pfnCreateSidToUidMap) (
        IN PCSTR pszNT4Name,
        IN PCSTR pSid,
        OUT uid_t* pUid
        );
    /* Create a sid to gid mapping */
    DWORD (*pfnCreateSidtoGidMap) (
        IN PCSTR pszNT4Name,
        IN PCSTR pSid,
        OUT gid_t* pGid
        );

    /* Map a uid to back to a sid */
    DWORD (*pfnQueryUidToSid) (
        IN uid_t uid,
        OUT PSTR pSid /* Buffer large enough to hold any valid sid */
        );

    /* Map a gid to back to a sid */
    DWORD (*pfnQueryGidToSid) (
        IN gid_t gid,
        OUT PSTR pSid /* Buffer large enough to hold any valid sid */
        );
#endif
} LSA_UNPROVISIONED_MODE_PLUGIN_FUNCTION_TABLE, *PLSA_UNPROVISIONED_MODE_PLUGIN_FUNCTION_TABLE;

We will provide headers for several functions so that mappers can call into
the LSASS utility library to read configuration settings.