windows-nt/Source/XPSP1/NT/termsrv/common/tssec/clicert.c
2020-09-26 16:20:57 +08:00

390 lines
7.9 KiB
C

/*++
Copyright (c) 1994-1998 Microsoft Corporation
Module Name:
clicert.c
Abstract:
Contains code related to the tshare certificate validation and data
encryption using server public key.
Author:
Madan Appiah (madana) 24-Jan-1998
Environment:
User Mode - Win32
Revision History:
--*/
#include <seccom.h>
BOOL
UnpackServerCert(
LPBYTE pbCert,
DWORD dwCertLen,
PHydra_Server_Cert pServerCert
)
/*++
Routine Description:
This function unpacks the blob of server certicate to server certificate
structure.
Arguments:
pbCert - pointer to the server public key blob.
dwCertLen - length of the above server public key.
pServerCert - pointer to a server certificate structure.
Return Value:
TRUE - if successfully unpacked.
FALSE - otherwise.
--*/
{
LPBYTE pbScan;
DWORD cbScan;
//
// return if the pointer are invalid.
// return if the certificate is insufficient length.
//
if( (pbCert == NULL) ||
(dwCertLen < (3 * sizeof(DWORD) + 4 * sizeof(WORD))) ||
(pServerCert == NULL) ) {
return( FALSE );
}
pbScan = pbCert;
cbScan = dwCertLen;
//
// Assign dwVersion
//
pServerCert->dwVersion = *(DWORD UNALIGNED FAR *)pbScan;
pbScan += sizeof(DWORD);
cbScan -= sizeof(DWORD);
//
// Assign dwSigAlgID
//
pServerCert->dwSigAlgID = *(DWORD UNALIGNED FAR *)pbScan;
pbScan += sizeof(DWORD);
cbScan -= sizeof(DWORD);
//
// Assign dwSignID
//
pServerCert->dwKeyAlgID = *(DWORD UNALIGNED FAR *)pbScan;
pbScan += sizeof(DWORD);
cbScan -= sizeof(DWORD);
//
//Assign PublicKeyData
//
pServerCert->PublicKeyData.wBlobType = *(WORD UNALIGNED FAR *)pbScan;
pbScan += sizeof(WORD);
cbScan -= sizeof(WORD);
if( pServerCert->PublicKeyData.wBlobType != BB_RSA_KEY_BLOB ) {
return( FALSE );
}
pServerCert->PublicKeyData.wBlobLen = *(WORD UNALIGNED FAR *)pbScan;
pbScan += sizeof(WORD);
cbScan -= sizeof(WORD);
if( pServerCert->PublicKeyData.wBlobLen > 0 ) {
if(cbScan < pServerCert->PublicKeyData.wBlobLen) {
return ( FALSE );
}
pServerCert->PublicKeyData.pBlob = pbScan;
pbScan += pServerCert->PublicKeyData.wBlobLen;
cbScan -= pServerCert->PublicKeyData.wBlobLen;
}
else {
pServerCert->PublicKeyData.pBlob = NULL;
}
//
// Assign SignatureBlob
//
if(cbScan < sizeof(WORD)) {
return ( FALSE );
}
pServerCert->SignatureBlob.wBlobType = *(WORD UNALIGNED *)pbScan;
pbScan += sizeof(WORD);
cbScan -= sizeof(WORD);
if( pServerCert->SignatureBlob.wBlobType != BB_RSA_SIGNATURE_BLOB ) {
return( FALSE );
}
if(cbScan < sizeof(WORD)) {
return ( FALSE );
}
pServerCert->SignatureBlob.wBlobLen = *(WORD UNALIGNED FAR *)pbScan;
pbScan += sizeof(WORD);
cbScan -= sizeof(WORD);
if( pServerCert->SignatureBlob.wBlobLen > 0 ) {
if(cbScan < pServerCert->SignatureBlob.wBlobLen) {
return ( FALSE );
}
pServerCert->SignatureBlob.pBlob = pbScan;
}
else {
pServerCert->SignatureBlob.pBlob = NULL;
}
return( TRUE );
}
BOOL
ValidateServerCert(
PHydra_Server_Cert pServerCert
)
/*++
Routine Description:
This function validate the server public key.
Arguments:
pSserverCert - pointer to a server certificate.
Return Value:
TRUE - if the server public key is valid.
FALSE - otherwise.
--*/
{
DWORD dwLen;
LPBYTE pbSignature;
MD5_CTX HashState;
BYTE SignHash[0x48];
LPBYTE pbScan;
//
// pack the certificate data into a byte blob excluding the signature info.
//
dwLen =
3 * sizeof(DWORD) +
2 * sizeof(WORD) +
pServerCert->PublicKeyData.wBlobLen;
//
// allocated space for the binary blob.
//
pbSignature = malloc( (UINT)dwLen );
if( pbSignature == NULL ) {
return( FALSE );
}
pbScan = pbSignature;
memcpy( pbScan, &pServerCert->dwVersion, sizeof(DWORD));
pbScan += sizeof(DWORD);
memcpy( pbScan, &pServerCert->dwSigAlgID, sizeof(DWORD));
pbScan += sizeof(DWORD);
memcpy( pbScan, &pServerCert->dwKeyAlgID, sizeof(DWORD));
pbScan += sizeof(DWORD);
memcpy( pbScan, &pServerCert->PublicKeyData.wBlobType, sizeof(WORD));
pbScan += sizeof(WORD);
memcpy( pbScan, &pServerCert->PublicKeyData.wBlobLen, sizeof(WORD));
pbScan += sizeof(WORD);
memcpy(
pbScan,
pServerCert->PublicKeyData.pBlob,
pServerCert->PublicKeyData.wBlobLen);
//
// generate the hash on the data.
//
MD5Init( &HashState );
MD5Update( &HashState, pbSignature, dwLen );
MD5Final( &HashState );
//
// free the signature blob, we don't need it anymore.
//
free( pbSignature );
//
// initialize the pulic key.
//
g_pPublicKey = (LPBSAFE_PUB_KEY)g_abPublicKeyModulus;
g_pPublicKey->magic = RSA1;
g_pPublicKey->keylen = 0x48;
g_pPublicKey->bitlen = 0x0200;
g_pPublicKey->datalen = 0x3f;
g_pPublicKey->pubexp = 0xc0887b5b;
//
// decrypt the signature.
//
memset(SignHash, 0x00, 0x48);
BSafeEncPublic( g_pPublicKey, pServerCert->SignatureBlob.pBlob, SignHash);
//
// compare the hash value.
//
if( memcmp( SignHash, HashState.digest, 16 )) {
return( FALSE );
}
//
// successfully validated the signature.
//
return( TRUE );
}
BOOL
EncryptClientRandom(
LPBYTE pbSrvPublicKey,
DWORD dwSrvPublicKey,
LPBYTE pbRandomKey,
DWORD dwRandomKeyLen,
LPBYTE pbEncRandomKey,
LPDWORD pdwEncRandomKey
)
/*++
Routine Description:
Encrypt the client random using server's public key.
Arguments:
pbSrvPublicKey - pointer to the server public key.
dwSrvPublicKey - length of the server public key.
pbRandomKey - pointer to a buffer where the client random key.
dwRandomKeyLen - length of the random key passed in.
pbEncRandomKey - pointer to a buffer where the encrypted client random is
returned.
pdwEncRandomKey - pointer to a place where the length of the above buffer is
passed in and length of the buffer used/required is returned.
Return Value:
TRUE - if the key is encrypted successfully.
FALSE - otherwise.
--*/
{
LPBSAFE_PUB_KEY pSrvPublicKey;
BYTE abInputBuffer[512];
ASSERT( pbSrvPublicKey != NULL );
pSrvPublicKey = (LPBSAFE_PUB_KEY)pbSrvPublicKey;
//
// check to see buffer length pointer is valid.
//
if( pdwEncRandomKey == NULL ) {
return( FALSE );
}
//
// check to see a output buffer is specified and
// the encrypt buffer length is sufficient.
//
if( (pbEncRandomKey == NULL) ||
(*pdwEncRandomKey < pSrvPublicKey->keylen) ) {
*pdwEncRandomKey = pSrvPublicKey->keylen;
return( FALSE );
}
//
// make sure the random key data and its length are valid.
//
ASSERT( pbRandomKey != NULL );
ASSERT( dwRandomKeyLen <= pSrvPublicKey->datalen );
ASSERT( pSrvPublicKey->datalen < pSrvPublicKey->keylen );
ASSERT( pSrvPublicKey->keylen <= sizeof(abInputBuffer) );
//
// init the input buffer.
//
memset( abInputBuffer, 0x0, (UINT)pSrvPublicKey->keylen );
//
// copy data to be encrypted in the input buffer.
//
memcpy( abInputBuffer, pbRandomKey, (UINT)dwRandomKeyLen );
//
// initialize the output buffer.
//
memset( pbEncRandomKey, 0x0, (UINT)pSrvPublicKey->keylen );
//
// encrypt data now.
//
if( !BSafeEncPublic(
pSrvPublicKey,
(LPBYTE)abInputBuffer,
pbEncRandomKey ) ) {
*pdwEncRandomKey = 0;
return( FALSE );
}
//
// successfully encrypted the client random,
// return the encrypted data length.
//
*pdwEncRandomKey = pSrvPublicKey->keylen;
return( TRUE );
}