*************************************************/
/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
/* See the file NOTICE for conditions of use and distribution. */
/* This file, which provides support for Microsoft's Secure Password
SPAAuthResponse response;
SPAAuthResponse *responseptr = &response;
uschar msgbuf[2048];
-uschar *clearpass;
+uschar *clearpass, *s;
+unsigned off;
/* send a 334, MS Exchange style, and grab the client's request,
unless we already have it via an initial response. */
-if ((*data == '\0') &&
- (auth_get_no64_data(&data, US"NTLM supported") != OK))
- {
- /* something borked */
+if (!*data && auth_get_no64_data(&data, US"NTLM supported") != OK)
return FAIL;
- }
-if (spa_base64_to_bits(CS (&request), sizeof(request), CCS (data)) < 0)
+if (spa_base64_to_bits(CS &request, sizeof(request), CCS data) < 0)
{
DEBUG(D_auth) debug_printf("auth_spa_server(): bad base64 data in "
- "request: %s\n", data);
+ "request: %s\n", data);
return FAIL;
}
/* create a challenge and send it back */
-spa_build_auth_challenge(&request,&challenge);
-spa_bits_to_base64 (msgbuf, (unsigned char*)&challenge,
- spa_request_length(&challenge));
+spa_build_auth_challenge(&request, &challenge);
+spa_bits_to_base64(msgbuf, US &challenge, spa_request_length(&challenge));
if (auth_get_no64_data(&data, msgbuf) != OK)
- {
- /* something borked */
return FAIL;
- }
/* dump client response */
-if (spa_base64_to_bits(CS (&response), sizeof(response), CCS (data)) < 0)
+if (spa_base64_to_bits(CS &response, sizeof(response), CCS data) < 0)
{
DEBUG(D_auth) debug_printf("auth_spa_server(): bad base64 data in "
- "response: %s\n", data);
+ "response: %s\n", data);
return FAIL;
}
{
int i;
- char *p = ((char*)responseptr) + IVAL(&responseptr->uUser.offset,0);
+ char * p;
int len = SVAL(&responseptr->uUser.len,0)/2;
+ if ( (off = IVAL(&responseptr->uUser.offset,0)) >= sizeof(SPAAuthResponse)
+ || len >= sizeof(responseptr->buffer)/2
+ || (p = (CS responseptr) + off) + len*2 >= CS (responseptr+1)
+ )
+ {
+ DEBUG(D_auth)
+ debug_printf("auth_spa_server(): bad uUser spec in response\n");
+ return FAIL;
+ }
+
if (len + 1 >= sizeof(msgbuf)) return FAIL;
for (i = 0; i < len; ++i)
{
/* look up password */
-clearpass = expand_string(ob->spa_serverpassword);
-if (clearpass == NULL)
- {
+if (!(clearpass = expand_string(ob->spa_serverpassword)))
if (f.expand_string_forcedfail)
{
DEBUG(D_auth) debug_printf("auth_spa_server(): forced failure while "
"spa_serverpassword: %s\n", expand_string_message);
return DEFER;
}
- }
/* create local hash copy */
-spa_smb_encrypt (clearpass, challenge.challengeData, lmRespData);
-spa_smb_nt_encrypt (clearpass, challenge.challengeData, ntRespData);
+spa_smb_encrypt(clearpass, challenge.challengeData, lmRespData);
+spa_smb_nt_encrypt(clearpass, challenge.challengeData, ntRespData);
/* compare NT hash (LM may not be available) */
-if (memcmp(ntRespData,
- ((unsigned char*)responseptr)+IVAL(&responseptr->ntResponse.offset,0),
- 24) == 0)
- /* success. we have a winner. */
+off = IVAL(&responseptr->ntResponse.offset,0);
+if (off >= sizeof(SPAAuthResponse) - 24)
{
- return auth_check_serv_cond(ablock);
+ DEBUG(D_auth)
+ debug_printf("auth_spa_server(): bad ntRespData spec in response\n");
+ return FAIL;
}
+s = (US responseptr) + off;
+
+if (memcmp(ntRespData, s, 24) == 0)
+ return auth_check_serv_cond(ablock); /* success. we have a winner. */
/* Expand server_condition as an authorization check (PH) */
DSPA("\n\n%s authenticator: using domain %s\n\n", ablock->name, domain);
-spa_build_auth_request (&request, CS username, domain);
-spa_bits_to_base64 (US msgbuf, (unsigned char*)&request,
- spa_request_length(&request));
+spa_build_auth_request(&request, CS username, domain);
+spa_bits_to_base64(US msgbuf, US &request, spa_request_length(&request));
DSPA("\n\n%s authenticator: sending request (%s)\n\n", ablock->name, msgbuf);
/* convert the challenge into the challenge struct */
DSPA("\n\n%s authenticator: challenge (%s)\n\n", ablock->name, buffer + 4);
-spa_base64_to_bits (CS (&challenge), sizeof(challenge), CCS (buffer + 4));
+spa_base64_to_bits(CS (&challenge), sizeof(challenge), CCS (buffer + 4));
-spa_build_auth_response (&challenge, &response, CS username, CS password);
-spa_bits_to_base64 (US msgbuf, (unsigned char*)&response,
- spa_request_length(&response));
+spa_build_auth_response(&challenge, &response, CS username, CS password);
+spa_bits_to_base64(US msgbuf, US &response, spa_request_length(&response));
DSPA("\n\n%s authenticator: challenge response (%s)\n\n", ablock->name, msgbuf);
/* send the challenge response */