/*
 * COPYRIGHT:         See COPYING in the top level directory
 * PROJECT:           ReactOS system libraries
 * PURPOSE:           Security manager
 * FILE:              lib/rtl/sid.c
 * PROGRAMER:         David Welch <welch@cwcom.net>
 */

/* INCLUDES *****************************************************************/

#include <rtl.h>
#define NDEBUG
#include <debug.h>

#define TAG_SID 'diSp'

/* FUNCTIONS ***************************************************************/

BOOLEAN
NTAPI
RtlValidSid(IN PSID Sid_)
{
    PISID Sid = Sid_;
    PAGED_CODE_RTL();

    /* Use SEH in case any pointer is invalid */
    _SEH2_TRY
    {
        /* Validate the revision and subauthority count */
        if ((Sid) &&
            (((Sid->Revision & 0xF) != SID_REVISION) ||
             (Sid->SubAuthorityCount > SID_MAX_SUB_AUTHORITIES)))
        {
            /* It's not, fail */
            _SEH2_YIELD(return FALSE);
        }
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        /* Access violation, SID is not valid */
        _SEH2_YIELD(return FALSE);
    }
    _SEH2_END;

    /* All good */
    return TRUE;
}

/*
 * @implemented
 */
ULONG
NTAPI
RtlLengthRequiredSid(IN ULONG SubAuthorityCount)
{
    PAGED_CODE_RTL();

    /* Return the required length */
    return (ULONG)FIELD_OFFSET(SID,
                               SubAuthority[SubAuthorityCount]);
}

/*
 * @implemented
 */
NTSTATUS
NTAPI
RtlInitializeSid(IN PSID Sid_,
                 IN PSID_IDENTIFIER_AUTHORITY IdentifierAuthority,
                 IN UCHAR SubAuthorityCount)
{
    PISID Sid = Sid_;
    PAGED_CODE_RTL();

    /* Fill out the header */
    Sid->Revision = SID_REVISION;
    Sid->SubAuthorityCount = SubAuthorityCount;
    Sid->IdentifierAuthority = *IdentifierAuthority;

    /* All good */
    return STATUS_SUCCESS;
}

/*
 * @implemented
 */
PULONG
NTAPI
RtlSubAuthoritySid(IN PSID Sid_,
                   IN ULONG SubAuthority)
{
    PISID Sid = Sid_;
    PAGED_CODE_RTL();

    /* Return the offset */
    return (PULONG)&Sid->SubAuthority[SubAuthority];
}

/*
 * @implemented
 */
PUCHAR
NTAPI
RtlSubAuthorityCountSid(IN PSID Sid_)
{
    PISID Sid =  Sid_;
    PAGED_CODE_RTL();

    /* Return the offset to the count */
    return &Sid->SubAuthorityCount;
}

/*
 * @implemented
 */
PSID_IDENTIFIER_AUTHORITY
NTAPI
RtlIdentifierAuthoritySid(IN PSID Sid_)
{
    PISID Sid =  Sid_;
    PAGED_CODE_RTL();

    /* Return the offset to the identifier authority */
    return &Sid->IdentifierAuthority;
}

/*
 * @implemented
 */
BOOLEAN
NTAPI
RtlEqualSid(IN PSID Sid1_,
            IN PSID Sid2_)
{
    PISID Sid1 = Sid1_, Sid2 = Sid2_;
    PAGED_CODE_RTL();

    /* Quick compare of the revision and the count */
    if (*(PUSHORT)&Sid1->Revision != *(PUSHORT)&Sid2->Revision) return FALSE;

    /* Get the length and compare it the long way */
    return RtlEqualMemory(Sid1, Sid2, RtlLengthSid(Sid1));
}

/*
 * @implemented
 */
ULONG
NTAPI
RtlLengthSid(IN PSID Sid_)
{
    PISID Sid = Sid_;
    PAGED_CODE_RTL();

    /* The offset to the last index + 1 (since it's a count) is the length */
    return (ULONG)FIELD_OFFSET(SID,
                               SubAuthority[Sid->SubAuthorityCount]);
}

/*
 * @implemented
 */
NTSTATUS
NTAPI
RtlCopySid(IN ULONG BufferLength,
           IN PSID Dest,
           IN PSID Src)
{
    ULONG SidLength;
    PAGED_CODE_RTL();

    /* Make sure the buffer is large enough*/
    SidLength = RtlLengthSid(Src);
    if (SidLength > BufferLength) return STATUS_BUFFER_TOO_SMALL;

    /* And then copy the SID */
    RtlMoveMemory(Dest, Src, SidLength);
    return STATUS_SUCCESS;
}

/*
 * @implemented
 */
PVOID
NTAPI
RtlFreeSid(IN PSID Sid)
{
    PAGED_CODE_RTL();

    /* Free the SID and always return NULL */
    RtlpFreeMemory(Sid, TAG_SID);
    return NULL;
}

/*
 * @implemented
 */
BOOLEAN
NTAPI
RtlEqualPrefixSid(IN PSID Sid1_,
                  IN PSID Sid2_)
{
    PISID Sid1 = Sid1_, Sid2 = Sid2_;
    ULONG i;
    PAGED_CODE_RTL();

    /* Revisions have to match */
    if (Sid1->Revision != Sid2->Revision) return FALSE;

    /* The identifier authorities have to match */
    if ((Sid1->IdentifierAuthority.Value[0] == Sid2->IdentifierAuthority.Value[0]) &&
        (Sid1->IdentifierAuthority.Value[1] == Sid2->IdentifierAuthority.Value[1]) &&
        (Sid1->IdentifierAuthority.Value[2] == Sid2->IdentifierAuthority.Value[2]) &&
        (Sid1->IdentifierAuthority.Value[3] == Sid2->IdentifierAuthority.Value[3]) &&
        (Sid1->IdentifierAuthority.Value[4] == Sid2->IdentifierAuthority.Value[4]) &&
        (Sid1->IdentifierAuthority.Value[5] == Sid2->IdentifierAuthority.Value[5]))
    {
        /* The subauthority counts have to match */
        if (Sid1->SubAuthorityCount == Sid2->SubAuthorityCount)
        {
            /* If there aren't any in SID1, means none in SID2 either, so equal */
            if (!Sid1->SubAuthorityCount) return TRUE;

            /* Now compare all the subauthority values BUT the last one */
            for (i = 0; (i + 1) < Sid1->SubAuthorityCount; i++)
            {
                /* Does any mismatch? */
                if (Sid1->SubAuthority[i] != Sid2->SubAuthority[i])
                {
                    /* Prefix doesn't match, fail */
                    return FALSE;
                }
            }

            /* Everything that should matches, does, return success */
            return TRUE;
        }
    }

    /* Identifiers don't match, fail */
    return FALSE;
}

/*
 * @implemented
 */
NTSTATUS
NTAPI
RtlCopySidAndAttributesArray(IN ULONG Count,
                             IN PSID_AND_ATTRIBUTES Src,
                             IN ULONG SidAreaSize,
                             IN PSID_AND_ATTRIBUTES Dest,
                             IN PSID SidArea,
                             OUT PSID* RemainingSidArea,
                             OUT PULONG RemainingSidAreaSize)
{
    ULONG SidLength, i;
    PAGED_CODE_RTL();

    /* Loop all the attributes */
    for (i = 0; i < Count; i++)
    {
        /* Make sure this SID can fit in the buffer */
        SidLength = RtlLengthSid(Src[i].Sid);
        if (SidLength > SidAreaSize) return STATUS_BUFFER_TOO_SMALL;

        /* Consume remaining buffer space for this SID */
        SidAreaSize -= SidLength;

        /* Copy the SID and attributes */
        Dest[i].Sid = SidArea;
        Dest[i].Attributes = Src[i].Attributes;
        RtlCopySid(SidLength, SidArea, Src[i].Sid);

        /* Push the buffer area where the SID will reset */
        SidArea = (PSID)((ULONG_PTR)SidArea + SidLength);
    }

    /* Return how much space is left, and where the buffer is at now */
    *RemainingSidArea = SidArea;
    *RemainingSidAreaSize = SidAreaSize;
    return STATUS_SUCCESS;
}

/*
 * @implemented
 */
NTSTATUS
NTAPI
RtlAllocateAndInitializeSid(IN PSID_IDENTIFIER_AUTHORITY IdentifierAuthority,
                            IN UCHAR SubAuthorityCount,
                            IN ULONG SubAuthority0,
                            IN ULONG SubAuthority1,
                            IN ULONG SubAuthority2,
                            IN ULONG SubAuthority3,
                            IN ULONG SubAuthority4,
                            IN ULONG SubAuthority5,
                            IN ULONG SubAuthority6,
                            IN ULONG SubAuthority7,
                            OUT PSID *Sid)
{
    PISID pSid;
    PAGED_CODE_RTL();

    /* SIDs can only have up to 8 subauthorities */
    if (SubAuthorityCount > 8) return STATUS_INVALID_SID;

    /* Allocate memory to hold the SID */
    pSid = RtlpAllocateMemory(RtlLengthRequiredSid(SubAuthorityCount), TAG_SID);
    if (!pSid) return STATUS_NO_MEMORY;

    /* Fill out the header */
    pSid->Revision = SID_REVISION;
    pSid->SubAuthorityCount = SubAuthorityCount;
    pSid->IdentifierAuthority = *IdentifierAuthority;

    /* Iteraratively drop into each successive lower count */
    switch (SubAuthorityCount)
    {
        /* And copy the needed subahority */
        case 8: pSid->SubAuthority[7] = SubAuthority7;
        case 7: pSid->SubAuthority[6] = SubAuthority6;
        case 6: pSid->SubAuthority[5] = SubAuthority5;
        case 5: pSid->SubAuthority[4] = SubAuthority4;
        case 4: pSid->SubAuthority[3] = SubAuthority3;
        case 3: pSid->SubAuthority[2] = SubAuthority2;
        case 2: pSid->SubAuthority[1] = SubAuthority1;
        case 1: pSid->SubAuthority[0] = SubAuthority0;
        default: break;
    }

    /* Return the allocated SID */
    *Sid = pSid;
    return STATUS_SUCCESS;
}

/*
 * @implemented
 */
NTSTATUS
NTAPI
RtlConvertSidToUnicodeString(IN PUNICODE_STRING String,
                             IN PSID Sid_,
                             IN BOOLEAN AllocateBuffer)
{
    WCHAR Buffer[256];
    PWSTR wcs;
    SIZE_T Length;
    ULONG i;
    PISID Sid = Sid_;
    PAGED_CODE_RTL();

    if (!RtlValidSid(Sid)) return STATUS_INVALID_SID;

    wcs = Buffer;
    wcs += swprintf(wcs, L"S-1-");

    if ((Sid->IdentifierAuthority.Value[0] == 0) &&
        (Sid->IdentifierAuthority.Value[1] == 0))
    {
        wcs += swprintf(wcs,
                        L"%lu",
                        (ULONG)Sid->IdentifierAuthority.Value[2] << 24 |
                        (ULONG)Sid->IdentifierAuthority.Value[3] << 16 |
                        (ULONG)Sid->IdentifierAuthority.Value[4] << 8 |
                        (ULONG)Sid->IdentifierAuthority.Value[5]);
    }
    else
    {
        wcs += swprintf(wcs,
                        L"0x%02hx%02hx%02hx%02hx%02hx%02hx",
                        Sid->IdentifierAuthority.Value[0],
                        Sid->IdentifierAuthority.Value[1],
                        Sid->IdentifierAuthority.Value[2],
                        Sid->IdentifierAuthority.Value[3],
                        Sid->IdentifierAuthority.Value[4],
                        Sid->IdentifierAuthority.Value[5]);
    }

    for (i = 0; i < Sid->SubAuthorityCount; i++)
    {
        wcs += swprintf(wcs, L"-%u", Sid->SubAuthority[i]);
    }

    if (AllocateBuffer)
    {
        if (!RtlCreateUnicodeString(String, Buffer)) return STATUS_NO_MEMORY;
    }
    else
    {
        Length = (wcs - Buffer) * sizeof(WCHAR);

        if (Length > String->MaximumLength) return STATUS_BUFFER_TOO_SMALL;

        String->Length = (USHORT)Length;
        RtlCopyMemory(String->Buffer, Buffer, Length);

        if (Length < String->MaximumLength)
        {
            String->Buffer[Length / sizeof(WCHAR)] = UNICODE_NULL;
        }
    }

    return STATUS_SUCCESS;
}

/*
 * @unimplemented
 */
NTSTATUS
NTAPI
RtlCreateServiceSid(
    _In_ PUNICODE_STRING ServiceName,
    _Out_writes_bytes_opt_(*ServiceSidLength) PSID ServiceSid,
    _Inout_ PULONG ServiceSidLength)
{
    UNIMPLEMENTED;
    return STATUS_NOT_IMPLEMENTED;
}

/* EOF */