sess.c 14.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
/*
 *   fs/cifs/sess.c
 *
 *   SMB/CIFS session setup handling routines
 *
 *   Copyright (c) International Business Machines  Corp., 2006
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "ntlmssp.h"
#include "nterr.h"
#include <linux/ctype.h>
32
#include <linux/utsname.h>
33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512

extern void SMBencrypt(unsigned char *passwd, unsigned char *c8,
                       unsigned char *p24);

extern void SMBNTencrypt(unsigned char *passwd, unsigned char *c8,
                         unsigned char *p24);

#ifdef CONFIG_CIFS_EXPERIMENTAL

static __u32 cifs_ssetup_hdr(struct cifsSesInfo *ses, SESSION_SETUP_ANDX *pSMB)
{
	__u32 capabilities = 0;

	/* init fields common to all four types of SessSetup */
	/* note that header is initialized to zero in header_assemble */
	pSMB->req.AndXCommand = 0xFF;
	pSMB->req.MaxBufferSize = cpu_to_le16(ses->server->maxBuf);
	pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);

	/* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */

	/* BB verify whether signing required on neg or just on auth frame 
	   (and NTLM case) */

	capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
			CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;

	if(ses->server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
		pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;

	if (ses->capabilities & CAP_UNICODE) {
		pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
		capabilities |= CAP_UNICODE;
	}
	if (ses->capabilities & CAP_STATUS32) {
		pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
		capabilities |= CAP_STATUS32;
	}
	if (ses->capabilities & CAP_DFS) {
		pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
		capabilities |= CAP_DFS;
	}
	if (ses->capabilities & CAP_UNIX) {
		capabilities |= CAP_UNIX;
	}

	/* BB check whether to init vcnum BB */
	return capabilities;
}

void unicode_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
			    const struct nls_table * nls_cp)
{
	char * bcc_ptr = *pbcc_area;
	int bytes_ret = 0;

	/* BB FIXME add check that strings total less
	than 335 or will need to send them as arrays */

	/* align unicode strings, must be word aligned */
	if ((long) bcc_ptr % 2)	{
		*bcc_ptr = 0;
		bcc_ptr++;
	}
	/* copy user */
	if(ses->userName == NULL) {
		/* BB what about null user mounts - check that we do this BB */
	} else { /* 300 should be long enough for any conceivable user name */
		bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->userName,
					  300, nls_cp);
	}
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2; /* account for null termination */
	/* copy domain */
	if(ses->domainName == NULL)
		bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr,
					  "CIFS_LINUX_DOM", 32, nls_cp);
	else
		bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->domainName, 
					  256, nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2;  /* account for null terminator */

	/* Copy OS version */
	bytes_ret = cifs_strtoUCS((__le16 *)bcc_ptr, "Linux version ", 32,
				  nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, system_utsname.release,
				  32, nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2; /* trailing null */

	bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
                                  32, nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2; /* trailing null */

	*pbcc_area = bcc_ptr;
}

void ascii_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
			  const struct nls_table * nls_cp)
{
	char * bcc_ptr = *pbcc_area;

	/* copy user */
	/* BB what about null user mounts - check that we do this BB */
        /* copy user */
        if(ses->userName == NULL) {
                /* BB what about null user mounts - check that we do this BB */
        } else { /* 300 should be long enough for any conceivable user name */
                strncpy(bcc_ptr, ses->userName, 300);
        }
	/* BB improve check for overflow */
        bcc_ptr += strnlen(ses->userName, 200);
	*bcc_ptr = 0;
        bcc_ptr++; /* account for null termination */

        /* copy domain */
	
        if(ses->domainName == NULL) {
                strcpy(bcc_ptr, "CIFS_LINUX_DOM");
		bcc_ptr += 14;  /* strlen(CIFS_LINUX_DOM) */
 	} else {
                strncpy(bcc_ptr, ses->domainName, 256); 
		bcc_ptr += strnlen(ses->domainName, 256);
	}
	*bcc_ptr = 0;
	bcc_ptr++;

	/* BB check for overflow here */

	strcpy(bcc_ptr, "Linux version ");
	bcc_ptr += strlen("Linux version ");
	strcpy(bcc_ptr, system_utsname.release);
	bcc_ptr += strlen(system_utsname.release) + 1;

	strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
	bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;

        *pbcc_area = bcc_ptr;
}

int decode_unicode_ssetup(char ** pbcc_area, int bleft, struct cifsSesInfo *ses,
                            const struct nls_table * nls_cp)
{
	int rc = 0;
	int words_left, len;
	char * data = *pbcc_area;



	cFYI(1,("bleft %d",bleft));


	/* word align, if bytes remaining is not even */
	if(bleft % 2) {
		bleft--;
		data++;
	}
	words_left = bleft / 2;

	/* save off server operating system */
	len = UniStrnlen((wchar_t *) data, words_left);

/* We look for obvious messed up bcc or strings in response so we do not go off
   the end since (at least) WIN2K and Windows XP have a major bug in not null
   terminating last Unicode string in response  */
	if(len >= words_left)
		return rc;

	if(ses->serverOS)
		kfree(ses->serverOS);
	/* UTF-8 string will not grow more than four times as big as UCS-16 */
	ses->serverOS = kzalloc(4 * len, GFP_KERNEL);
	if(ses->serverOS != NULL) {
		cifs_strfromUCS_le(ses->serverOS, (__le16 *)data, len,
				   nls_cp);
	}
	data += 2 * (len + 1);
	words_left -= len + 1;

	/* save off server network operating system */
	len = UniStrnlen((wchar_t *) data, words_left);

	if(len >= words_left)
		return rc;

	if(ses->serverNOS)
		kfree(ses->serverNOS);
	ses->serverNOS = kzalloc(4 * len, GFP_KERNEL); /* BB this is wrong length FIXME BB */
	if(ses->serverNOS != NULL) {
		cifs_strfromUCS_le(ses->serverNOS, (__le16 *)data, len,
				   nls_cp);
		if(strncmp(ses->serverNOS, "NT LAN Manager 4",16) == 0) {
			cFYI(1,("NT4 server"));
			ses->flags |= CIFS_SES_NT4;
		}
	}
	data += 2 * (len + 1);
	words_left -= len + 1;

        /* save off server domain */
        len = UniStrnlen((wchar_t *) data, words_left);

        if(len > words_left)
                return rc;

        if(ses->serverDomain)
                kfree(ses->serverDomain);
        ses->serverDomain = kzalloc(2 * (len + 1), GFP_KERNEL); /* BB FIXME wrong length */
        if(ses->serverDomain != NULL) {
                cifs_strfromUCS_le(ses->serverDomain, (__le16 *)data, len,
                                   nls_cp);
                ses->serverDomain[2*len] = 0;
                ses->serverDomain[(2*len) + 1] = 0;
        }
        data += 2 * (len + 1);
        words_left -= len + 1;
	
	cFYI(1,("words left: %d",words_left));

	return rc;
}

int decode_ascii_ssetup(char ** pbcc_area, int bleft, struct cifsSesInfo *ses,
                            const struct nls_table * nls_cp)
{
	int rc = 0;
	int len;
	char * bcc_ptr = *pbcc_area;

	cFYI(1,("decode sessetup ascii. bleft %d", bleft));
	
	len = strnlen(bcc_ptr, bleft);
	if(len >= bleft)
		return rc;
	
	if(ses->serverOS)
		kfree(ses->serverOS);

	ses->serverOS = kzalloc(len + 1, GFP_KERNEL);
	if(ses->serverOS)
		strncpy(ses->serverOS, bcc_ptr, len);

	bcc_ptr += len + 1;
	bleft -= len + 1;

	len = strnlen(bcc_ptr, bleft);
	if(len >= bleft)
		return rc;

	if(ses->serverNOS)
		kfree(ses->serverNOS);

	ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);
	if(ses->serverNOS)
		strncpy(ses->serverNOS, bcc_ptr, len);

	bcc_ptr += len + 1;
	bleft -= len + 1;

        len = strnlen(bcc_ptr, bleft);
        if(len > bleft)
                return rc;

        if(ses->serverDomain)
                kfree(ses->serverDomain);

        ses->serverDomain = kzalloc(len + 1, GFP_KERNEL);
        if(ses->serverOS)
                strncpy(ses->serverOS, bcc_ptr, len);

        bcc_ptr += len + 1;
	bleft -= len + 1;

	cFYI(1,("ascii: bytes left %d",bleft));

	return rc;
}

int 
CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
		const struct nls_table *nls_cp)
{
	int rc = 0;
	int wct;
	int i;
	struct smb_hdr *smb_buf;
	char *bcc_ptr;
	SESSION_SETUP_ANDX *pSMB;
	__u32 capabilities;
	int count;
	int resp_buf_type = 0;
	struct kvec iov[1];
	enum securityEnum type;
	__u16 action;
	int bytes_remaining;
	
	if(ses == NULL)
		return -EINVAL;

	type = ses->server->secType;
	if(type == LANMAN) {
#ifndef CONFIG_CIFS_WEAK_PW_HASH
		/* LANMAN and plaintext are less secure and off by default.
		So we make this explicitly be turned on in kconfig (in the
		build) and turned on at runtime (changed from the default)
		in proc/fs/cifs or via mount parm.  Unfortunately this is
		needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
		return -EOPNOTSUPP;
#endif
		wct = 10; /* lanman 2 style sessionsetup */
	} else if(type == NTLM) /* NTLMv2 may retry NTLM */
		wct = 13; /* old style NTLM sessionsetup */
	else /* same size for negotiate or auth, NTLMSSP or extended security */
		wct = 12;

	rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
			    (void **)&smb_buf);
	if(rc)
		return rc;

	pSMB = (SESSION_SETUP_ANDX *)smb_buf;

	capabilities = cifs_ssetup_hdr(ses, pSMB);
	bcc_ptr = pByteArea(smb_buf);

	if(type == LANMAN) {
#ifdef CONFIG_CIFS_WEAK_PW_HASH
		char lnm_session_key[CIFS_SESSION_KEY_SIZE];
		char password_with_pad[CIFS_ENCPWD_SIZE];

		/* no capabilities flags in old lanman negotiation */

		pSMB->old_req.PasswordLength = CIFS_SESSION_KEY_SIZE; 
		/* BB calculate hash with password */
		/* and copy into bcc */

		memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
		strncpy(password_with_pad, ses->password, CIFS_ENCPWD_SIZE);

		/* calculate old style session key */
		/* toupper may be less broken then repeatedly calling
		nls_toupper would be, but neither handles multibyte code pages
		but the only alternative would be converting to UCS-16 (Unicode)
		uppercasing and converting back which is only worth doing if
		we knew it were utf8. utf8 code page needs its own
		toupper and tolower and strnicmp functions */
		
		for(i = 0; i< CIFS_ENCPWD_SIZE; i++) {
			password_with_pad[i] = toupper(password_with_pad[i]);
		}

		SMBencrypt(password_with_pad, ses->server->cryptKey,
			   lnm_session_key);

#ifdef CONFIG_CIFS_DEBUG2
		cifs_dump_mem("cryptkey: ",ses->server->cryptKey,
			CIFS_SESSION_KEY_SIZE);
#endif
		/* clear password before we return/free memory */
		memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
		memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_SESSION_KEY_SIZE);
		bcc_ptr += CIFS_SESSION_KEY_SIZE;

		/* can not sign if LANMAN negotiated so no need
		to calculate signing key? but what if server
		changed to do higher than lanman dialect and
		we reconnected would we ever calc signing_key? */

		cERROR(1,("Negotiating LANMAN setting up strings"));
		/* Unicode not allowed for LANMAN dialects */
		ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
#endif    
	} else if (type == NTLM) {
		char ntlm_session_key[CIFS_SESSION_KEY_SIZE];

		pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
		pSMB->req_no_secext.CaseInsensitivePasswordLength =
			cpu_to_le16(CIFS_SESSION_KEY_SIZE);
		pSMB->req_no_secext.CaseSensitivePasswordLength =
			cpu_to_le16(CIFS_SESSION_KEY_SIZE);
	
		/* calculate session key */
		SMBNTencrypt(ses->password, ses->server->cryptKey,
			     ntlm_session_key);

		if(first_time) /* should this be moved into common code 
				  with similar ntlmv2 path? */
			cifs_calculate_mac_key(
				ses->server->mac_signing_key,
				ntlm_session_key, ses->password);
		/* copy session key */

		memcpy(bcc_ptr, (char *)ntlm_session_key,CIFS_SESSION_KEY_SIZE);
		bcc_ptr += CIFS_SESSION_KEY_SIZE;
		memcpy(bcc_ptr, (char *)ntlm_session_key,CIFS_SESSION_KEY_SIZE);
		bcc_ptr += CIFS_SESSION_KEY_SIZE;
		if(ses->capabilities & CAP_UNICODE)
			unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
		else
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
	} else /* NTLMSSP or SPNEGO */ {
		pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
		capabilities |= CAP_EXTENDED_SECURITY;
		pSMB->req.Capabilities = cpu_to_le32(capabilities);
		/* BB set password lengths */
	}

	count = (long) bcc_ptr - (long) pByteArea(smb_buf);
	smb_buf->smb_buf_length += count;

	/* if we switch to small buffers, count will need to be fewer
	   than 383 (strings less than 335 bytes) */

	BCC_LE(smb_buf) = cpu_to_le16(count);


	/* BB FIXME check for other non ntlm code paths */

	/* BB check is this too big for a small smb? */

	iov[0].iov_base = (char *)pSMB;
	iov[0].iov_len = smb_buf->smb_buf_length + 4;

	rc = SendReceive2(xid, ses, iov, 1 /* num_iovecs */, &resp_buf_type, 0);
	/* SMB request buf freed in SendReceive2 */

	cFYI(1,("ssetup rc from sendrecv2 is %d",rc));
	if(rc)
		goto ssetup_exit;

	pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
	smb_buf = (struct smb_hdr *)iov[0].iov_base;

	if((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
		rc = -EIO;
		cERROR(1,("bad word count %d", smb_buf->WordCount));
		goto ssetup_exit;
	}
	action = le16_to_cpu(pSMB->resp.Action);
	if (action & GUEST_LOGIN)
		cFYI(1, (" Guest login")); /* BB mark SesInfo struct? */
	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
	cFYI(1, ("UID = %d ", ses->Suid));
	/* response can have either 3 or 4 word count - Samba sends 3 */
	/* and lanman response is 3 */
	bytes_remaining = BCC(smb_buf);
	bcc_ptr = pByteArea(smb_buf);

	if(smb_buf->WordCount == 4) {
		__u16 blob_len;
		blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
		bcc_ptr += blob_len;
		if(blob_len > bytes_remaining) {
			cERROR(1,("bad security blob length %d", blob_len));
			rc = -EINVAL;
			goto ssetup_exit;
		}
		bytes_remaining -= blob_len;
	}	

	/* BB check if Unicode and decode strings */
	if(smb_buf->Flags2 & SMBFLG2_UNICODE)
		rc = decode_unicode_ssetup(&bcc_ptr, bytes_remaining,
						   ses, nls_cp);
	else
		rc = decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,nls_cp);
	
ssetup_exit:
	if(resp_buf_type == CIFS_SMALL_BUFFER) {
		cFYI(1,("ssetup freeing small buf %p", iov[0].iov_base));
		cifs_small_buf_release(iov[0].iov_base);
	} else if(resp_buf_type == CIFS_LARGE_BUFFER)
		cifs_buf_release(iov[0].iov_base);

	return rc;
}
#endif /* CONFIG_CIFS_EXPERIMENTAL */