Leaked source code of windows server 2003
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///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 1998, Microsoft Corp. All rights reserved.
//
// FILE
//
// ezsam.c
//
// SYNOPSIS
//
// Defines helper functions for SAM API.
//
// MODIFICATION HISTORY
//
// 08/16/1998 Original version.
// 02/18/1999 Connect by DNS name not address.
// 03/23/1999 Tighten up the ezsam API.
// Better failover/retry logic.
// 04/14/1999 Copy SIDs returned by IASSamOpenUser.
//
///////////////////////////////////////////////////////////////////////////////
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#include <ntlsa.h>
#include <windows.h>
#include <lm.h>
#include <dsgetdc.h>
#include <statinfo.h>
#include <ezsam.h>
#include <iastrace.h>
//////////
// Private helper functions.
//////////
DWORD
WINAPI
IASSamOpenDomain(
IN PCWSTR DomainName,
IN ACCESS_MASK DesiredAccess,
IN ULONG Flags,
IN BOOL Force,
OUT PSID *DomainSid,
OUT PSAM_HANDLE DomainHandle
);
VOID
WINAPI
IASSamFreeSid(
IN PSID Sid
);
VOID
WINAPI
IASSamCloseDomain(
IN SAM_HANDLE SamHandle,
IN BOOL Valid
);
DWORD
WINAPI
IASSamLookupUser(
IN SAM_HANDLE DomainHandle,
IN PCWSTR UserName,
IN ACCESS_MASK DesiredAccess,
IN OUT OPTIONAL PULONG UserRid,
OUT PSAM_HANDLE UserHandle
);
//////////
// Handles for the local SAM domains.
//////////
SAM_HANDLE theAccountDomainHandle;
SAM_HANDLE theBuiltinDomainHandle;
//////////
// State associated with a cached domain.
//////////
struct CachedDomain
{
LONG lock; // 1 if the cache is locked, 0 otherwise.
WCHAR domainName[DNLEN + 1]; // Domain name.
ACCESS_MASK access; // Access mask for handle.
ULARGE_INTEGER expiry; // Time when entry expires.
PSID sid; // SID for the domain.
SAM_HANDLE handle; // Handle to domain.
LONG refCount; // Reference count.
};
//////////
// Time in 100 nsec intervals that a cache entry will be retained.
// Set to 900 seconds.
//////////
#define CACHE_LIFETIME (9000000000ui64)
//////////
// The currently cached domain.
//////////
struct CachedDomain theCache;
//////////
// Try to lock the cache.
//////////
#define TRYLOCK_CACHE() \
(InterlockedExchange(&theCache.lock, 1) == 0)
//////////
// Unlock the cache.
//////////
#define UNLOCK_CACHE() \
(InterlockedExchange(&theCache.lock, 0))
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamSidDup
//
// DESCRIPTION
//
// Duplicates the passed in SID. The SID should be freed by calling
// IASSamFreeSid.
//
///////////////////////////////////////////////////////////////////////////////
PSID
WINAPI
IASSamSidDup(
PSID Sid
)
{
ULONG sidLength;
PSID rv;
if (Sid)
{
sidLength = RtlLengthSid(Sid);
rv = RtlAllocateHeap(
RtlProcessHeap(),
0,
sidLength
);
if (rv) { memcpy(rv, Sid, sidLength); }
}
else
{
rv = NULL;
}
return rv;
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamOpenCachedDomain
//
// DESCRIPTION
//
// Attempt to open a domain from the cache.
//
///////////////////////////////////////////////////////////////////////////////
BOOL
WINAPI
IASSamOpenCachedDomain(
IN PCWSTR DomainName,
IN ACCESS_MASK DesiredAccess,
OUT PSID *DomainSid,
OUT PSAM_HANDLE DomainHandle
)
{
BOOL success;
ULARGE_INTEGER now;
success = FALSE;
// Can we access the cache ?
if (TRYLOCK_CACHE())
{
// Does the domain name match ?
if (_wcsicmp(DomainName, theCache.domainName) == 0)
{
// Does the cached handle have sufficient access rights ?
if ((DesiredAccess & theCache.access) == DesiredAccess)
{
GetSystemTimeAsFileTime((LPFILETIME)&now);
// Is the entry still valid ?
if (now.QuadPart < theCache.expiry.QuadPart)
{
// We got a cache hit, so update the reference count ...
InterlockedIncrement(&theCache.refCount);
// ... and return the data.
*DomainSid = theCache.sid;
*DomainHandle = theCache.handle;
success = TRUE;
}
else
{
// The entry has expired, so NULL out the name to prevent the
// next thread from wasting its time.
theCache.domainName[0] = L'\0';
}
}
}
UNLOCK_CACHE();
}
return success;
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamAddCachedDomain
//
// DESCRIPTION
//
// Attempt to add a domain to the cache.
//
///////////////////////////////////////////////////////////////////////////////
VOID
WINAPI
IASSamAddCachedDomain(
IN PCWSTR DomainName,
IN ACCESS_MASK Access,
IN PSID DomainSid,
IN SAM_HANDLE DomainHandle
)
{
// Can we access the cache ?
if (TRYLOCK_CACHE())
{
// Is the current entry idle ?
if (theCache.refCount == 0)
{
// Free the current entry.
SamCloseHandle(theCache.handle);
SamFreeMemory(theCache.sid);
// Store the cached state.
wcsncpy(theCache.domainName, DomainName, DNLEN);
theCache.access = Access;
theCache.sid = DomainSid;
theCache.handle = DomainHandle;
// Set the expiration time.
GetSystemTimeAsFileTime((LPFILETIME)&theCache.expiry);
theCache.expiry.QuadPart += CACHE_LIFETIME;
// The caller already has a reference.
theCache.refCount = 1;
}
UNLOCK_CACHE();
}
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamInitialize
//
// DESCRIPTION
//
// Initializes the handles for the local SAM domains.
//
///////////////////////////////////////////////////////////////////////////////
DWORD
WINAPI
IASSamInitialize( VOID )
{
DWORD status;
SAM_HANDLE hLocalServer;
UNICODE_STRING uniAccountDomain;
//////////
// Connect to the local SAM.
//////////
status = SamConnect(
NULL,
&hLocalServer,
SAM_SERVER_LOOKUP_DOMAIN,
&theObjectAttributes
);
if (!NT_SUCCESS(status)) { goto exit; }
//////////
// Open a handle to the account domain.
//////////
status = SamOpenDomain(
hLocalServer,
DOMAIN_LOOKUP |
DOMAIN_GET_ALIAS_MEMBERSHIP |
DOMAIN_READ_PASSWORD_PARAMETERS,
theAccountDomainSid,
&theAccountDomainHandle
);
if (!NT_SUCCESS(status)) { goto close_server; }
//////////
// Open a handle to the built-in domain.
//////////
status = SamOpenDomain(
hLocalServer,
DOMAIN_LOOKUP |
DOMAIN_GET_ALIAS_MEMBERSHIP,
theBuiltinDomainSid,
&theBuiltinDomainHandle
);
if (!NT_SUCCESS(status))
{
SamCloseHandle(theAccountDomainHandle);
theAccountDomainHandle = NULL;
}
close_server:
SamCloseHandle(hLocalServer);
exit:
return RtlNtStatusToDosError(status);
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamShutdown
//
// DESCRIPTION
//
// Cleans up global variables.
//
///////////////////////////////////////////////////////////////////////////////
VOID
WINAPI
IASSamShutdown( VOID )
{
// Reset the cache.
SamFreeMemory(theCache.sid);
SamCloseHandle(theCache.handle);
memset(&theCache, 0, sizeof(theCache));
SamCloseHandle(theAccountDomainHandle);
theAccountDomainHandle = NULL;
SamCloseHandle(theBuiltinDomainHandle);
theBuiltinDomainHandle = NULL;
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamOpenDomain
//
// DESCRIPTION
//
// Opens a connection to a SAM domain. The caller is responsible for
// closing the returned handle and freeing the returned SID.
//
///////////////////////////////////////////////////////////////////////////////
DWORD
WINAPI
IASSamOpenDomain(
IN PCWSTR DomainName,
IN ACCESS_MASK DesiredAccess,
IN ULONG Flags,
IN BOOL Force,
OUT PSID *DomainSid,
OUT PSAM_HANDLE DomainHandle
)
{
DWORD status;
PDOMAIN_CONTROLLER_INFOW dci;
UNICODE_STRING uniServerName, uniDomainName;
SAM_HANDLE hServer;
//////////
// First check for the local account domain.
//////////
if (_wcsicmp(DomainName, theAccountDomain) == 0)
{
*DomainSid = theAccountDomainSid;
*DomainHandle = theAccountDomainHandle;
IASTraceString("Using cached SAM connection to local account domain.");
return NO_ERROR;
}
//////////
// Try for a cache hit.
//////////
if (IASSamOpenCachedDomain(
DomainName,
DesiredAccess,
DomainSid,
DomainHandle
))
{
IASTraceString("Using cached SAM connection.");
return NO_ERROR;
}
//////////
// No luck, so get the name of the DC to connect to.
//////////
status = IASGetDcName(
DomainName,
(Force ? DS_FORCE_REDISCOVERY : 0) | Flags,
&dci
);
if (status != NO_ERROR) { return status; }
//////////
// Connect to the server.
//////////
IASTracePrintf("Connecting to SAM server on %S.",
dci->DomainControllerName);
RtlInitUnicodeString(
&uniServerName,
dci->DomainControllerName
);
status = SamConnect(
&uniServerName,
&hServer,
SAM_SERVER_LOOKUP_DOMAIN,
&theObjectAttributes
);
// We're through with the server name.
NetApiBufferFree(dci);
if (!NT_SUCCESS(status)) { goto exit; }
//////////
// Get SID for the domain.
//////////
RtlInitUnicodeString(
&uniDomainName,
DomainName
);
status = SamLookupDomainInSamServer(
hServer,
&uniDomainName,
DomainSid
);
if (!NT_SUCCESS(status)) { goto close_server; }
//////////
// Open the domain using SID we got above
//////////
status = SamOpenDomain(
hServer,
DesiredAccess,
*DomainSid,
DomainHandle
);
if (NT_SUCCESS(status))
{
// Try to add this to the cache.
IASSamAddCachedDomain(
DomainName,
DesiredAccess,
*DomainSid,
*DomainHandle
);
}
else
{
// Free the SID. We can use SamFreeMemory since we know this SID isn't
// in the cache.
SamFreeMemory(*DomainSid);
*DomainSid = NULL;
}
close_server:
SamCloseHandle(hServer);
exit:
return RtlNtStatusToDosError(status);
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamLookupUser
//
// DESCRIPTION
//
// Opens a user in a SAM domain. The caller is responsible for closing
// the returned handle.
//
///////////////////////////////////////////////////////////////////////////////
DWORD
WINAPI
IASSamLookupUser(
IN SAM_HANDLE DomainHandle,
IN PCWSTR UserName,
IN ACCESS_MASK DesiredAccess,
IN OUT OPTIONAL PULONG UserRid,
OUT PSAM_HANDLE UserHandle
)
{
DWORD status;
UNICODE_STRING uniUserName;
ULONG rid, *prid;
PSID_NAME_USE nameUse;
if (UserName)
{
//////////
// Caller supplied a UserName so lookup the RID.
//////////
RtlInitUnicodeString(
&uniUserName,
UserName
);
status = SamLookupNamesInDomain(
DomainHandle,
1,
&uniUserName,
&prid,
&nameUse
);
if (!NT_SUCCESS(status)) { goto exit; }
// Save the RID ...
rid = *prid;
// ... and free the memory.
SamFreeMemory(prid);
SamFreeMemory(nameUse);
// Return the RID to the caller if requested.
if (UserRid)
{
*UserRid = rid;
}
}
else if (UserRid)
{
// Caller supplied a RID.
rid = *UserRid;
}
else
{
// Caller supplied neither a UserName or a RID.
return ERROR_INVALID_PARAMETER;
}
//////////
// Open the user object.
//////////
status = SamOpenUser(
DomainHandle,
DesiredAccess,
rid,
UserHandle
);
exit:
return RtlNtStatusToDosError(status);
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamOpenUser
//
// DESCRIPTION
//
// Opens a SAM user. The caller is responsible for closing
// the returned handle.
//
///////////////////////////////////////////////////////////////////////////////
DWORD
WINAPI
IASSamOpenUser(
IN PCWSTR DomainName,
IN PCWSTR UserName,
IN ACCESS_MASK DesiredAccess,
IN ULONG Flags,
IN OUT OPTIONAL PULONG UserRid,
OUT OPTIONAL PSID *DomainSid,
OUT PSAM_HANDLE UserHandle
)
{
DWORD status;
ULONG tries;
PSID sid;
SAM_HANDLE hDomain;
BOOL success;
// Initialize the retry state.
tries = 0;
success = FALSE;
do
{
//////////
// Open a connection to the domain.
//////////
status = IASSamOpenDomain(
DomainName,
DOMAIN_LOOKUP,
Flags,
(tries > 0),
&sid,
&hDomain
);
if (status == NO_ERROR)
{
//////////
// Lookup the user.
//////////
status = IASSamLookupUser(
hDomain,
UserName,
DesiredAccess,
UserRid,
UserHandle
);
switch (status)
{
case NO_ERROR:
// Everything succeeded, so return the domain SID if requested.
if (DomainSid && !(*DomainSid = IASSamSidDup(sid)))
{
SamCloseHandle(*UserHandle);
*UserHandle = NULL;
status = STATUS_NO_MEMORY;
}
// Fall through.
case ERROR_NONE_MAPPED:
success = TRUE;
break;
}
// Free the sid ...
IASSamFreeSid(sid);
// ... and the domain handle.
IASSamCloseDomain(hDomain, success);
}
} while (!success && ++tries < 2);
return status;
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamCloseDomain
//
// DESCRIPTION
//
// Closes a handle returned by IASSamOpenDomain.
//
///////////////////////////////////////////////////////////////////////////////
VOID
WINAPI
IASSamCloseDomain(
IN SAM_HANDLE SamHandle,
IN BOOL Valid
)
{
if (SamHandle == theCache.handle)
{
if (!Valid)
{
theCache.domainName[0] = L'\0';
}
InterlockedDecrement(&theCache.refCount);
}
else if (SamHandle != theAccountDomainHandle)
{
SamCloseHandle(SamHandle);
}
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASSamFreeSid
//
// DESCRIPTION
//
// Frees a SID returned by IASSamOpenDomain.
//
///////////////////////////////////////////////////////////////////////////////
VOID
WINAPI
IASSamFreeSid (
IN PSID Sid
)
{
if (Sid != theAccountDomainSid && Sid != theCache.sid)
{
SamFreeMemory(Sid);
}
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASLengthRequiredChildSid
//
// DESCRIPTION
//
// Returns the number of bytes required for a SID immediately subordinate
// to ParentSid.
//
///////////////////////////////////////////////////////////////////////////////
ULONG
WINAPI
IASLengthRequiredChildSid(
IN PSID ParentSid
)
{
// Get the parent's SubAuthority count.
ULONG subAuthCount;
subAuthCount = (ULONG)*RtlSubAuthorityCountSid(ParentSid);
// And add one for the child RID.
return RtlLengthRequiredSid(1 + subAuthCount);
}
///////////////////////////////////////////////////////////////////////////////
//
// FUNCTION
//
// IASInitializeChildSid
//
// DESCRIPTION
//
// Initializes a SID with the concatenation of ParentSid + ChildRid.
//
///////////////////////////////////////////////////////////////////////////////
VOID
WINAPI
IASInitializeChildSid(
IN PSID ChildSid,
IN PSID ParentSid,
IN ULONG ChildRid
)
{
PUCHAR pChildCount;
ULONG parentCount;
// Start with the parent SID. We assume the child SID is big enough.
RtlCopySid(
MAXLONG,
ChildSid,
ParentSid
);
// Get a pointer to the child SubAuthority count.
pChildCount = RtlSubAuthorityCountSid(ChildSid);
// Save the original parent count ...
parentCount = (ULONG)*pChildCount;
// ... then increment the child count.
++*pChildCount;
// Set the last subauthority equal to the RID.
*RtlSubAuthoritySid(ChildSid, parentCount) = ChildRid;
}