crypt.c File Reference

#include "ksecdd.h"

Include dependency graph for crypt.c:

Go to the source code of this file.

Classes
struct	_KSEC_PROCESS_DATA
struct	_KSEC_LOGON_DATA

Typedefs
typedef struct _KSEC_PROCESS_DATA	KSEC_PROCESS_DATA
typedef struct _KSEC_PROCESS_DATA *	PKSEC_PROCESS_DATA
typedef struct _KSEC_LOGON_DATA	KSEC_LOGON_DATA
typedef struct _KSEC_LOGON_DATA *	PKSEC_LOGON_DATA

Functions
VOID NTAPI	KsecInitializeEncryptionSupport (VOID)
static VOID	KsecGetKeyData (_Out_ UCHAR KeyData[32], _In_ ULONG OptionFlags)
static VOID	KsecGetDes3Key (_Out_ PDES3_KEY Des3Key, _In_ ULONG OptionFlags)
static VOID	KsecGetAesKey (_Out_ PAES_KEY AesKey, _In_ ULONG OptionFlags)
static VOID	KsecEncryptMemoryDes3 (_Inout_ PVOID Buffer, _In_ ULONG Length, _In_ ULONG OptionFlags)
static VOID	KsecDecryptMemoryDes3 (_Inout_ PVOID Buffer, _In_ ULONG Length, _In_ ULONG OptionFlags)
static VOID	KsecEncryptMemoryAes (_Inout_ PVOID Buffer, _In_ ULONG Length, _In_ ULONG OptionFlags)
static VOID	KsecDecryptMemoryAes (_Inout_ PVOID Buffer, _In_ ULONG Length, _In_ ULONG OptionFlags)
NTSTATUS NTAPI	KsecEncryptMemory (_Inout_ PVOID Buffer, _In_ ULONG Length, _In_ ULONG OptionFlags)
NTSTATUS NTAPI	KsecDecryptMemory (_Inout_ PVOID Buffer, _In_ ULONG Length, _In_ ULONG OptionFlags)

Variables
MD5_CTX	KsecLoadTimeStartMd5s [2]
DES3_KEY	KsecGlobalDes3Key
AES_KEY	KsecGlobalAesKey

Typedef Documentation

KSEC_LOGON_DATA

typedef struct _KSEC_LOGON_DATA KSEC_LOGON_DATA

KSEC_PROCESS_DATA

typedef struct _KSEC_PROCESS_DATA KSEC_PROCESS_DATA

PKSEC_LOGON_DATA

typedef struct _KSEC_LOGON_DATA * PKSEC_LOGON_DATA

PKSEC_PROCESS_DATA

typedef struct _KSEC_PROCESS_DATA * PKSEC_PROCESS_DATA

Function Documentation

KsecDecryptMemory()

NTSTATUS NTAPI KsecDecryptMemory	(	_Inout_ PVOID	Buffer,
		_In_ ULONG	Length,
		_In_ ULONG	OptionFlags
	)

Definition at line 327 of file crypt.c.

{
    /* Validate parameter */
    if (OptionFlags > RTL_ENCRYPT_OPTION_SAME_LOGON)
    {
        return STATUS_INVALID_PARAMETER;
    }
 
    /* Check if the length is not 16 bytes aligned */
    if (Length & 15)
    {
        /* Is it at least 8 bytes aligned? */
        if (Length & 7)
        {
            /* No, we can't deal with it! */
            return STATUS_INVALID_PARAMETER;
        }
 
        /* Use triple DES encryption */
        KsecDecryptMemoryDes3(Buffer, Length, OptionFlags);
    }
    else
    {
        /* Use AES encryption */
        KsecDecryptMemoryAes(Buffer, Length, OptionFlags);
    }
 
    return STATUS_SUCCESS;
}

Referenced by KsecDeviceControl().

KsecDecryptMemoryAes()

static VOID KsecDecryptMemoryAes ( _Inout_ PVOID  Buffer, _In_ ULONG  Length, _In_ ULONG  OptionFlags  )

static

Definition at line 266 of file crypt.c.

{
    UCHAR BlockData[16];
    AES_KEY AesKey;
 
    /* Get they AES key */
    KsecGetAesKey(&AesKey, OptionFlags);
 
    /* Do the AES decryption */
    while (Length >= sizeof(BlockData))
    {
        aes_ecb_decrypt(Buffer, BlockData, &AesKey);
        RtlCopyMemory(Buffer, BlockData, sizeof(BlockData));
        Buffer = (PUCHAR)Buffer + sizeof(BlockData);
        Length -= sizeof(BlockData);
    }
 
    /* Erase the key data */
    RtlSecureZeroMemory(&AesKey, sizeof(AesKey));
}

Referenced by KsecDecryptMemory().

KsecDecryptMemoryDes3()

static VOID KsecDecryptMemoryDes3 ( _Inout_ PVOID  Buffer, _In_ ULONG  Length, _In_ ULONG  OptionFlags  )

static

Definition at line 214 of file crypt.c.

{
    UCHAR BlockData[8];
    DES3_KEY Des3Key;
 
    /* Get they triple DES key */
    KsecGetDes3Key(&Des3Key, OptionFlags);
 
    /* Do the triple DES decryption */
    while (Length >= sizeof(BlockData))
    {
        des3_ecb_decrypt(Buffer, BlockData, &Des3Key);
        RtlCopyMemory(Buffer, BlockData, sizeof(BlockData));
        Buffer = (PUCHAR)Buffer + sizeof(BlockData);
        Length -= sizeof(BlockData);
    }
 
    /* Erase the key data */
    RtlSecureZeroMemory(&Des3Key, sizeof(Des3Key));
}

Referenced by KsecDecryptMemory().

KsecEncryptMemory()

NTSTATUS NTAPI KsecEncryptMemory	(	_Inout_ PVOID	Buffer,
		_In_ ULONG	Length,
		_In_ ULONG	OptionFlags
	)

Definition at line 292 of file crypt.c.

{
    /* Validate parameter */
    if (OptionFlags > RTL_ENCRYPT_OPTION_SAME_LOGON)
    {
        return STATUS_INVALID_PARAMETER;
    }
 
    /* Check if the length is not 16 bytes aligned */
    if (Length & 15)
    {
        /* Is it at least 8 bytes aligned? */
        if (Length & 7)
        {
            /* No, we can't deal with it! */
            return STATUS_INVALID_PARAMETER;
        }
 
        /* Use triple DES encryption */
        KsecEncryptMemoryDes3(Buffer, Length, OptionFlags);
    }
    else
    {
        /* Use AES encryption */
        KsecEncryptMemoryAes(Buffer, Length, OptionFlags);
    }
 
    return STATUS_SUCCESS;
}

Referenced by KsecDeviceControl().

KsecEncryptMemoryAes()

static VOID KsecEncryptMemoryAes ( _Inout_ PVOID  Buffer, _In_ ULONG  Length, _In_ ULONG  OptionFlags  )

static

Definition at line 240 of file crypt.c.

{
    UCHAR EncryptedBlockData[16];
    AES_KEY AesKey;
 
    /* Get they AES key */
    KsecGetAesKey(&AesKey, OptionFlags);
 
    /* Do the AES encryption */
    while (Length >= sizeof(EncryptedBlockData))
    {
        aes_ecb_encrypt(Buffer, EncryptedBlockData, &AesKey);
        RtlCopyMemory(Buffer, EncryptedBlockData, sizeof(EncryptedBlockData));
        Buffer = (PUCHAR)Buffer + sizeof(EncryptedBlockData);
        Length -= sizeof(EncryptedBlockData);
    }
 
    /* Erase the key data */
    RtlSecureZeroMemory(&AesKey, sizeof(AesKey));
}

Referenced by KsecEncryptMemory().

KsecEncryptMemoryDes3()

static VOID KsecEncryptMemoryDes3 ( _Inout_ PVOID  Buffer, _In_ ULONG  Length, _In_ ULONG  OptionFlags  )

static

Definition at line 188 of file crypt.c.

{
    UCHAR EncryptedBlockData[8];
    DES3_KEY Des3Key;
 
    /* Get they triple DES key */
    KsecGetDes3Key(&Des3Key, OptionFlags);
 
    /* Do the triple DES encryption */
    while (Length >= sizeof(EncryptedBlockData))
    {
        des3_ecb_encrypt(Buffer, EncryptedBlockData, &Des3Key);
        RtlCopyMemory(Buffer, EncryptedBlockData, sizeof(EncryptedBlockData));
        Buffer = (PUCHAR)Buffer + sizeof(EncryptedBlockData);
        Length -= sizeof(EncryptedBlockData);
    }
 
    /* Erase the key data */
    RtlSecureZeroMemory(&Des3Key, sizeof(Des3Key));
}

Referenced by KsecEncryptMemory().

KsecGetAesKey()

static VOID KsecGetAesKey ( _Out_ PAES_KEY  AesKey, _In_ ULONG  OptionFlags  )

static

Definition at line 163 of file crypt.c.

{
    UCHAR KeyDataBuffer[32];
 
    /* Check if the caller allows cross process encryption */
    if (OptionFlags == RTL_ENCRYPT_OPTION_CROSS_PROCESS)
    {
        /* Return our global cached AES key */
        *AesKey = KsecGlobalAesKey;
    }
    else
    {
        /* Setup the key */
        KsecGetKeyData(KeyDataBuffer, OptionFlags);
        aes_setup(KeyDataBuffer, 32, 0, AesKey);
 
        /* Erase the temp data */
        RtlSecureZeroMemory(KeyDataBuffer, sizeof(KeyDataBuffer));
    }
}

Referenced by KsecDecryptMemoryAes(), and KsecEncryptMemoryAes().

KsecGetDes3Key()

static VOID KsecGetDes3Key ( _Out_ PDES3_KEY  Des3Key, _In_ ULONG  OptionFlags  )

static

Definition at line 138 of file crypt.c.

{
    UCHAR KeyDataBuffer[32];
 
    /* Check if the caller allows cross process encryption */
    if (OptionFlags == RTL_ENCRYPT_OPTION_CROSS_PROCESS)
    {
        /* Return our global cached DES3 key */
        *Des3Key = KsecGlobalDes3Key;
    }
    else
    {
        /* Setup the key */
        KsecGetKeyData(KeyDataBuffer, OptionFlags);
        des3_setup(KeyDataBuffer, 24, 0, Des3Key);
 
        /* Erase the temp data */
        RtlSecureZeroMemory(KeyDataBuffer, sizeof(KeyDataBuffer));
    }
}

Referenced by KsecDecryptMemoryDes3(), and KsecEncryptMemoryDes3().

KsecGetKeyData()

static VOID KsecGetKeyData ( _Out_ UCHAR  KeyData[32], _In_ ULONG  OptionFlags  )

static

Definition at line 75 of file crypt.c.

{
    MD5_CTX Md5Contexts[2];
    KSEC_PROCESS_DATA ProcessData;
    KSEC_LOGON_DATA LogonData;
    PEPROCESS CurrentProcess;
    PACCESS_TOKEN Token;
 
    /* We need to generate the key, start with our load MD5s */
    Md5Contexts[0] = KsecLoadTimeStartMd5s[0];
    Md5Contexts[1] = KsecLoadTimeStartMd5s[1];
 
    /* Get the current process */
    CurrentProcess = PsGetCurrentProcess();
 
    if (OptionFlags == RTL_ENCRYPT_OPTION_SAME_PROCESS)
    {
        /* Hash some process specific data to generate the key */
        RtlZeroMemory(&ProcessData, sizeof(ProcessData));
        ProcessData.Process = CurrentProcess;
        ProcessData.ProcessId = CurrentProcess->UniqueProcessId;
        ProcessData.CreateTime = PsGetProcessCreateTimeQuadPart(CurrentProcess);
        ProcessData.DirectoryTableBase = CurrentProcess->Pcb.DirectoryTableBase[0];
        MD5Update(&Md5Contexts[0], (PVOID)&ProcessData, sizeof(ProcessData));
        MD5Update(&Md5Contexts[1], (PVOID)&ProcessData, sizeof(ProcessData));
    }
    else if (OptionFlags == RTL_ENCRYPT_OPTION_SAME_LOGON)
    {
        /* Hash the logon id to generate the key */
        RtlZeroMemory(&LogonData, sizeof(LogonData));
        Token = PsReferencePrimaryToken(CurrentProcess);
        SeQueryAuthenticationIdToken(Token, &LogonData.LogonId);
        PsDereferencePrimaryToken(Token);
        MD5Update(&Md5Contexts[0], (PVOID)&LogonData, sizeof(LogonData));
        MD5Update(&Md5Contexts[1], (PVOID)&LogonData, sizeof(LogonData));
    }
    else if (OptionFlags == RTL_ENCRYPT_OPTION_CROSS_PROCESS)
    {
        /* Use the original MD5s to generate the global key */
        NOTHING;
    }
    else
    {
        /* Must not pass anything else */
        ASSERT(FALSE);
    }
 
    /* Finalize the MD5s */
    MD5Final(&Md5Contexts[0]);
    MD5Final(&Md5Contexts[1]);
 
    /* Copy the md5 data */
    RtlCopyMemory(KeyData, &Md5Contexts[0].digest, 16);
    RtlCopyMemory((PUCHAR)KeyData + 16, &Md5Contexts[1].digest, 16);
 
    /* Erase the temp data */
    RtlSecureZeroMemory(&Md5Contexts, sizeof(Md5Contexts));
}

Referenced by KsecGetAesKey(), and KsecGetDes3Key().

KsecInitializeEncryptionSupport()

VOID NTAPI KsecInitializeEncryptionSupport

(

VOID

)

Definition at line 43 of file crypt.c.

{
    KSEC_ENTROPY_DATA EntropyData;
    MD5_CTX Md5Context;
    UCHAR KeyDataBuffer[32];
 
    KsecGatherEntropyData(&EntropyData);
    MD5Init(&Md5Context);
    MD5Update(&Md5Context, (PVOID)&EntropyData, sizeof(EntropyData));
    KsecLoadTimeStartMd5s[0] = Md5Context;
    MD5Final(&Md5Context);
    RtlCopyMemory(KeyDataBuffer, &Md5Context.digest, 16);
 
    KsecGatherEntropyData(&EntropyData);
    Md5Context = KsecLoadTimeStartMd5s[0];
    MD5Update(&Md5Context, (PVOID)&EntropyData, sizeof(EntropyData));
    KsecLoadTimeStartMd5s[1] = Md5Context;
    MD5Final(&Md5Context);
    RtlCopyMemory(&KeyDataBuffer[16], &Md5Context.digest, 16);
 
    /* Create the global keys */
    aes_setup(KeyDataBuffer, 32, 0, &KsecGlobalAesKey);
    des3_setup(KeyDataBuffer, 24, 0, &KsecGlobalDes3Key);
 
    /* Erase the temp data */
    RtlSecureZeroMemory(KeyDataBuffer, sizeof(KeyDataBuffer));
    RtlSecureZeroMemory(&Md5Context, sizeof(Md5Context));
}

Referenced by DriverEntry().

Variable Documentation

KsecGlobalAesKey

AES_KEY KsecGlobalAesKey

Definition at line 14 of file crypt.c.

Referenced by KsecGetAesKey(), and KsecInitializeEncryptionSupport().

KsecGlobalDes3Key

DES3_KEY KsecGlobalDes3Key

Definition at line 13 of file crypt.c.

Referenced by KsecGetDes3Key(), and KsecInitializeEncryptionSupport().

KsecLoadTimeStartMd5s

MD5_CTX KsecLoadTimeStartMd5s[2]

Definition at line 12 of file crypt.c.

Referenced by KsecGetKeyData(), and KsecInitializeEncryptionSupport().