1 /*- 2 * Copyright (c) 2000 Semen Ustimenko <semenu@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/usr.sbin/ppp/mppe.c,v 1.4.2.6 2002/09/01 02:12:29 brian Exp $ 27 * $DragonFly: src/usr.sbin/ppp/mppe.c,v 1.2 2003/06/17 04:30:00 dillon Exp $ 28 */ 29 30 #include <sys/param.h> 31 32 #include <sys/socket.h> 33 #include <netinet/in_systm.h> 34 #include <netinet/in.h> 35 #include <netinet/ip.h> 36 #include <sys/un.h> 37 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <termios.h> 42 #include <openssl/rc4.h> 43 44 #include "defs.h" 45 #include "mbuf.h" 46 #include "log.h" 47 #include "timer.h" 48 #include "fsm.h" 49 #include "lqr.h" 50 #include "hdlc.h" 51 #include "lcp.h" 52 #include "ccp.h" 53 #include "throughput.h" 54 #include "layer.h" 55 #include "link.h" 56 #include "chap_ms.h" 57 #include "proto.h" 58 #include "mppe.h" 59 #include "ua.h" 60 #include "descriptor.h" 61 #ifndef NORADIUS 62 #include "radius.h" 63 #endif 64 #include "ncpaddr.h" 65 #include "iplist.h" 66 #include "slcompress.h" 67 #include "ipcp.h" 68 #include "ipv6cp.h" 69 #include "filter.h" 70 #include "mp.h" 71 #include "ncp.h" 72 #include "bundle.h" 73 74 /* 75 * Documentation: 76 * 77 * draft-ietf-pppext-mppe-04.txt 78 * draft-ietf-pppext-mppe-keys-02.txt 79 */ 80 81 #define MPPE_OPT_STATELESS 0x1000000 82 #define MPPE_OPT_COMPRESSED 0x01 83 #define MPPE_OPT_40BIT 0x20 84 #define MPPE_OPT_56BIT 0x80 85 #define MPPE_OPT_128BIT 0x40 86 #define MPPE_OPT_BITMASK 0xe0 87 #define MPPE_OPT_MASK (MPPE_OPT_STATELESS | MPPE_OPT_BITMASK) 88 89 #define MPPE_FLUSHED 0x8000 90 #define MPPE_ENCRYPTED 0x1000 91 #define MPPE_HEADER_BITMASK 0xf000 92 #define MPPE_HEADER_FLAG 0x00ff 93 #define MPPE_HEADER_FLAGMASK 0x00ff 94 #define MPPE_HEADER_FLAGSHIFT 8 95 #define MPPE_HEADER_STATEFUL_KEYCHANGES 16 96 97 struct mppe_state { 98 unsigned stateless : 1; 99 unsigned flushnext : 1; 100 unsigned flushrequired : 1; 101 int cohnum; 102 int keylen; /* 8 or 16 bytes */ 103 int keybits; /* 40, 56 or 128 bits */ 104 char sesskey[MPPE_KEY_LEN]; 105 char mastkey[MPPE_KEY_LEN]; 106 RC4_KEY rc4key; 107 }; 108 109 int MPPE_MasterKeyValid = 0; 110 int MPPE_IsServer = 0; 111 char MPPE_MasterKey[MPPE_KEY_LEN]; 112 113 /* 114 * The peer has missed a packet. Mark the next output frame to be FLUSHED 115 */ 116 static int 117 MPPEResetOutput(void *v) 118 { 119 struct mppe_state *mop = (struct mppe_state *)v; 120 121 if (mop->stateless) 122 log_Printf(LogCCP, "MPPE: Unexpected output channel reset\n"); 123 else { 124 log_Printf(LogCCP, "MPPE: Output channel reset\n"); 125 mop->flushnext = 1; 126 } 127 128 return 0; /* Ask FSM not to ACK */ 129 } 130 131 static void 132 MPPEReduceSessionKey(struct mppe_state *mp) 133 { 134 switch(mp->keybits) { 135 case 40: 136 mp->sesskey[2] = 0x9e; 137 mp->sesskey[1] = 0x26; 138 case 56: 139 mp->sesskey[0] = 0xd1; 140 case 128: 141 break; 142 } 143 } 144 145 static void 146 MPPEKeyChange(struct mppe_state *mp) 147 { 148 char InterimKey[MPPE_KEY_LEN]; 149 RC4_KEY RC4Key; 150 151 GetNewKeyFromSHA(mp->mastkey, mp->sesskey, mp->keylen, InterimKey); 152 RC4_set_key(&RC4Key, mp->keylen, InterimKey); 153 RC4(&RC4Key, mp->keylen, InterimKey, mp->sesskey); 154 155 MPPEReduceSessionKey(mp); 156 } 157 158 static struct mbuf * 159 MPPEOutput(void *v, struct ccp *ccp, struct link *l, int pri, u_short *proto, 160 struct mbuf *mp) 161 { 162 struct mppe_state *mop = (struct mppe_state *)v; 163 struct mbuf *mo; 164 u_short nproto, prefix; 165 int dictinit, ilen, len; 166 char *rp; 167 168 ilen = m_length(mp); 169 dictinit = 0; 170 171 log_Printf(LogDEBUG, "MPPE: Output: Proto %02x (%d bytes)\n", *proto, ilen); 172 if (*proto < 0x21 && *proto > 0xFA) { 173 log_Printf(LogDEBUG, "MPPE: Output: Not encrypting\n"); 174 ccp->compout += ilen; 175 ccp->uncompout += ilen; 176 return mp; 177 } 178 179 log_DumpBp(LogDEBUG, "MPPE: Output: Encrypt packet:", mp); 180 181 /* Get mbuf for prefixes */ 182 mo = m_get(4, MB_CCPOUT); 183 mo->m_next = mp; 184 185 rp = MBUF_CTOP(mo); 186 prefix = MPPE_ENCRYPTED | mop->cohnum; 187 188 if (mop->stateless || 189 (mop->cohnum & MPPE_HEADER_FLAGMASK) == MPPE_HEADER_FLAG) { 190 /* Change our key */ 191 log_Printf(LogDEBUG, "MPPEOutput: Key changed [%d]\n", mop->cohnum); 192 MPPEKeyChange(mop); 193 dictinit = 1; 194 } 195 196 if (mop->stateless || mop->flushnext) { 197 prefix |= MPPE_FLUSHED; 198 dictinit = 1; 199 mop->flushnext = 0; 200 } 201 202 if (dictinit) { 203 /* Initialise our dictionary */ 204 log_Printf(LogDEBUG, "MPPEOutput: Dictionary initialised [%d]\n", 205 mop->cohnum); 206 RC4_set_key(&mop->rc4key, mop->keylen, mop->sesskey); 207 } 208 209 /* Set MPPE packet prefix */ 210 ua_htons(&prefix, rp); 211 212 /* Save encrypted protocol number */ 213 nproto = htons(*proto); 214 RC4(&mop->rc4key, 2, (char *)&nproto, rp + 2); 215 216 /* Encrypt main packet */ 217 rp = MBUF_CTOP(mp); 218 RC4(&mop->rc4key, ilen, rp, rp); 219 220 mop->cohnum++; 221 mop->cohnum &= ~MPPE_HEADER_BITMASK; 222 223 /* Set the protocol number */ 224 *proto = ccp_Proto(ccp); 225 len = m_length(mo); 226 ccp->uncompout += ilen; 227 ccp->compout += len; 228 229 log_Printf(LogDEBUG, "MPPE: Output: Encrypted: Proto %02x (%d bytes)\n", 230 *proto, len); 231 232 return mo; 233 } 234 235 static void 236 MPPEResetInput(void *v) 237 { 238 log_Printf(LogCCP, "MPPE: Unexpected input channel ack\n"); 239 } 240 241 static struct mbuf * 242 MPPEInput(void *v, struct ccp *ccp, u_short *proto, struct mbuf *mp) 243 { 244 struct mppe_state *mip = (struct mppe_state *)v; 245 u_short prefix; 246 char *rp; 247 int dictinit, flushed, ilen, len, n; 248 249 ilen = m_length(mp); 250 dictinit = 0; 251 ccp->compin += ilen; 252 253 log_Printf(LogDEBUG, "MPPE: Input: Proto %02x (%d bytes)\n", *proto, ilen); 254 log_DumpBp(LogDEBUG, "MPPE: Input: Packet:", mp); 255 256 mp = mbuf_Read(mp, &prefix, 2); 257 prefix = ntohs(prefix); 258 flushed = prefix & MPPE_FLUSHED; 259 prefix &= ~flushed; 260 if ((prefix & MPPE_HEADER_BITMASK) != MPPE_ENCRYPTED) { 261 log_Printf(LogERROR, "MPPE: Input: Invalid packet (flags = 0x%x)\n", 262 (prefix & MPPE_HEADER_BITMASK) | flushed); 263 m_freem(mp); 264 return NULL; 265 } 266 267 prefix &= ~MPPE_HEADER_BITMASK; 268 269 if (!flushed && mip->stateless) { 270 log_Printf(LogCCP, "MPPEInput: Packet without MPPE_FLUSHED set" 271 " in stateless mode\n"); 272 flushed = MPPE_FLUSHED; 273 /* Should we really continue ? */ 274 } 275 276 if (mip->stateless) { 277 /* Change our key for each missed packet in stateless mode */ 278 while (prefix != mip->cohnum) { 279 log_Printf(LogDEBUG, "MPPEInput: Key changed [%u]\n", prefix); 280 MPPEKeyChange(mip); 281 /* 282 * mip->cohnum contains what we received last time in stateless 283 * mode. 284 */ 285 mip->cohnum++; 286 mip->cohnum &= ~MPPE_HEADER_BITMASK; 287 } 288 dictinit = 1; 289 } else { 290 if (flushed) { 291 /* 292 * We can always process a flushed packet. 293 * Catch up on any outstanding key changes. 294 */ 295 n = (prefix >> MPPE_HEADER_FLAGSHIFT) - 296 (mip->cohnum >> MPPE_HEADER_FLAGSHIFT); 297 if (n < 0) 298 n += MPPE_HEADER_STATEFUL_KEYCHANGES; 299 while (n--) { 300 log_Printf(LogDEBUG, "MPPEInput: Key changed during catchup [%u]\n", 301 prefix); 302 MPPEKeyChange(mip); 303 } 304 mip->flushrequired = 0; 305 mip->cohnum = prefix; 306 dictinit = 1; 307 } 308 309 if (mip->flushrequired) { 310 /* 311 * Perhaps we should be lenient if 312 * (prefix & MPPE_HEADER_FLAGMASK) == MPPE_HEADER_FLAG 313 * The spec says that we shouldn't be though.... 314 */ 315 log_Printf(LogDEBUG, "MPPE: Not flushed - discarded\n"); 316 fsm_Output(&ccp->fsm, CODE_RESETREQ, ccp->fsm.reqid++, NULL, 0, 317 MB_CCPOUT); 318 m_freem(mp); 319 return NULL; 320 } 321 322 if (prefix != mip->cohnum) { 323 /* 324 * We're in stateful mode and didn't receive the expected 325 * packet. Send a reset request, but don't tell the CCP layer 326 * about it as we don't expect to receive a Reset ACK ! 327 * Guess what... M$ invented this ! 328 */ 329 log_Printf(LogCCP, "MPPE: Input: Got seq %u, not %u\n", 330 prefix, mip->cohnum); 331 fsm_Output(&ccp->fsm, CODE_RESETREQ, ccp->fsm.reqid++, NULL, 0, 332 MB_CCPOUT); 333 mip->flushrequired = 1; 334 m_freem(mp); 335 return NULL; 336 } 337 338 if ((prefix & MPPE_HEADER_FLAGMASK) == MPPE_HEADER_FLAG) { 339 log_Printf(LogDEBUG, "MPPEInput: Key changed [%u]\n", prefix); 340 MPPEKeyChange(mip); 341 dictinit = 1; 342 } else if (flushed) 343 dictinit = 1; 344 345 /* 346 * mip->cohnum contains what we expect to receive next time in stateful 347 * mode. 348 */ 349 mip->cohnum++; 350 mip->cohnum &= ~MPPE_HEADER_BITMASK; 351 } 352 353 if (dictinit) { 354 log_Printf(LogDEBUG, "MPPEInput: Dictionary initialised [%u]\n", prefix); 355 RC4_set_key(&mip->rc4key, mip->keylen, mip->sesskey); 356 } 357 358 mp = mbuf_Read(mp, proto, 2); 359 RC4(&mip->rc4key, 2, (char *)proto, (char *)proto); 360 *proto = ntohs(*proto); 361 362 rp = MBUF_CTOP(mp); 363 len = m_length(mp); 364 RC4(&mip->rc4key, len, rp, rp); 365 366 log_Printf(LogDEBUG, "MPPEInput: Decrypted: Proto %02x (%d bytes)\n", 367 *proto, len); 368 log_DumpBp(LogDEBUG, "MPPEInput: Decrypted: Packet:", mp); 369 370 ccp->uncompin += len; 371 372 return mp; 373 } 374 375 static void 376 MPPEDictSetup(void *v, struct ccp *ccp, u_short proto, struct mbuf *mi) 377 { 378 } 379 380 static const char * 381 MPPEDispOpts(struct fsm_opt *o) 382 { 383 static char buf[70]; 384 u_int32_t val; 385 char ch; 386 int len, n; 387 388 ua_ntohl(o->data, &val); 389 len = 0; 390 if ((n = snprintf(buf, sizeof buf, "value 0x%08x ", (unsigned)val)) > 0) 391 len += n; 392 if (!(val & MPPE_OPT_BITMASK)) { 393 if ((n = snprintf(buf + len, sizeof buf - len, "(0")) > 0) 394 len += n; 395 } else { 396 ch = '('; 397 if (val & MPPE_OPT_128BIT) { 398 if ((n = snprintf(buf + len, sizeof buf - len, "%c128", ch)) > 0) 399 len += n; 400 ch = '/'; 401 } 402 if (val & MPPE_OPT_56BIT) { 403 if ((n = snprintf(buf + len, sizeof buf - len, "%c56", ch)) > 0) 404 len += n; 405 ch = '/'; 406 } 407 if (val & MPPE_OPT_40BIT) { 408 if ((n = snprintf(buf + len, sizeof buf - len, "%c40", ch)) > 0) 409 len += n; 410 ch = '/'; 411 } 412 } 413 414 if ((n = snprintf(buf + len, sizeof buf - len, " bits, state%s", 415 (val & MPPE_OPT_STATELESS) ? "less" : "ful")) > 0) 416 len += n; 417 418 if (val & MPPE_OPT_COMPRESSED) { 419 if ((n = snprintf(buf + len, sizeof buf - len, ", compressed")) > 0) 420 len += n; 421 } 422 423 snprintf(buf + len, sizeof buf - len, ")"); 424 425 return buf; 426 } 427 428 static int 429 MPPEUsable(struct fsm *fp) 430 { 431 int ok; 432 #ifndef NORADIUS 433 struct radius *r = &fp->bundle->radius; 434 435 /* 436 * If the radius server gave us RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES, 437 * use that instead of our configuration value. 438 */ 439 if (*r->cfg.file) { 440 ok = r->mppe.sendkeylen && r->mppe.recvkeylen; 441 if (!ok) 442 log_Printf(LogCCP, "MPPE: Not permitted by RADIUS server\n"); 443 } else 444 #endif 445 { 446 struct lcp *lcp = &fp->link->lcp; 447 ok = (lcp->want_auth == PROTO_CHAP && lcp->want_authtype == 0x81) || 448 (lcp->his_auth == PROTO_CHAP && lcp->his_authtype == 0x81); 449 if (!ok) 450 log_Printf(LogCCP, "MPPE: Not usable without CHAP81\n"); 451 } 452 453 return ok; 454 } 455 456 static int 457 MPPERequired(struct fsm *fp) 458 { 459 #ifndef NORADIUS 460 /* 461 * If the radius server gave us RAD_MICROSOFT_MS_MPPE_ENCRYPTION_POLICY, 462 * use that instead of our configuration value. 463 */ 464 if (*fp->bundle->radius.cfg.file && fp->bundle->radius.mppe.policy) 465 return fp->bundle->radius.mppe.policy == MPPE_POLICY_REQUIRED ? 1 : 0; 466 #endif 467 468 return fp->link->ccp.cfg.mppe.required; 469 } 470 471 static u_int32_t 472 MPPE_ConfigVal(struct bundle *bundle, const struct ccp_config *cfg) 473 { 474 u_int32_t val; 475 476 val = cfg->mppe.state == MPPE_STATELESS ? MPPE_OPT_STATELESS : 0; 477 #ifndef NORADIUS 478 /* 479 * If the radius server gave us RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES, 480 * use that instead of our configuration value. 481 */ 482 if (*bundle->radius.cfg.file && bundle->radius.mppe.types) { 483 if (bundle->radius.mppe.types & MPPE_TYPE_40BIT) 484 val |= MPPE_OPT_40BIT; 485 if (bundle->radius.mppe.types & MPPE_TYPE_128BIT) 486 val |= MPPE_OPT_128BIT; 487 } else 488 #endif 489 switch(cfg->mppe.keybits) { 490 case 128: 491 val |= MPPE_OPT_128BIT; 492 break; 493 case 56: 494 val |= MPPE_OPT_56BIT; 495 break; 496 case 40: 497 val |= MPPE_OPT_40BIT; 498 break; 499 case 0: 500 val |= MPPE_OPT_128BIT | MPPE_OPT_56BIT | MPPE_OPT_40BIT; 501 break; 502 } 503 504 return val; 505 } 506 507 /* 508 * What options should we use for our first configure request 509 */ 510 static void 511 MPPEInitOptsOutput(struct bundle *bundle, struct fsm_opt *o, 512 const struct ccp_config *cfg) 513 { 514 u_int32_t mval; 515 516 o->hdr.len = 6; 517 518 if (!MPPE_MasterKeyValid) { 519 log_Printf(LogCCP, "MPPE: MasterKey is invalid," 520 " MPPE is available only with CHAP81 authentication\n"); 521 ua_htonl(0x0, o->data); 522 return; 523 } 524 525 526 mval = MPPE_ConfigVal(bundle, cfg); 527 ua_htonl(&mval, o->data); 528 } 529 530 /* 531 * Our CCP request was NAK'd with the given options 532 */ 533 static int 534 MPPESetOptsOutput(struct bundle *bundle, struct fsm_opt *o, 535 const struct ccp_config *cfg) 536 { 537 u_int32_t mval, peer; 538 539 ua_ntohl(o->data, &peer); 540 541 if (!MPPE_MasterKeyValid) 542 /* Treat their NAK as a REJ */ 543 return MODE_NAK; 544 545 mval = MPPE_ConfigVal(bundle, cfg); 546 547 /* 548 * If we haven't been configured with a specific number of keybits, allow 549 * whatever the peer asks for. 550 */ 551 if (!cfg->mppe.keybits) { 552 mval &= ~MPPE_OPT_BITMASK; 553 mval |= (peer & MPPE_OPT_BITMASK); 554 if (!(mval & MPPE_OPT_BITMASK)) 555 mval |= MPPE_OPT_128BIT; 556 } 557 558 /* Adjust our statelessness */ 559 if (cfg->mppe.state == MPPE_ANYSTATE) { 560 mval &= ~MPPE_OPT_STATELESS; 561 mval |= (peer & MPPE_OPT_STATELESS); 562 } 563 564 ua_htonl(&mval, o->data); 565 566 return MODE_ACK; 567 } 568 569 /* 570 * The peer has requested the given options 571 */ 572 static int 573 MPPESetOptsInput(struct bundle *bundle, struct fsm_opt *o, 574 const struct ccp_config *cfg) 575 { 576 u_int32_t mval, peer; 577 int res = MODE_ACK; 578 579 ua_ntohl(o->data, &peer); 580 if (!MPPE_MasterKeyValid) { 581 if (peer != 0) { 582 peer = 0; 583 ua_htonl(&peer, o->data); 584 return MODE_NAK; 585 } else 586 return MODE_ACK; 587 } 588 589 mval = MPPE_ConfigVal(bundle, cfg); 590 591 if (peer & ~MPPE_OPT_MASK) 592 /* He's asking for bits we don't know about */ 593 res = MODE_NAK; 594 595 if (peer & MPPE_OPT_STATELESS) { 596 if (cfg->mppe.state == MPPE_STATEFUL) 597 /* Peer can't have stateless */ 598 res = MODE_NAK; 599 else 600 /* Peer wants stateless, that's ok */ 601 mval |= MPPE_OPT_STATELESS; 602 } else { 603 if (cfg->mppe.state == MPPE_STATELESS) 604 /* Peer must have stateless */ 605 res = MODE_NAK; 606 else 607 /* Peer doesn't want stateless, that's ok */ 608 mval &= ~MPPE_OPT_STATELESS; 609 } 610 611 /* If we've got a configured number of keybits - the peer must use that */ 612 if (cfg->mppe.keybits) { 613 ua_htonl(&mval, o->data); 614 return peer == mval ? res : MODE_NAK; 615 } 616 617 /* If a specific number of bits hasn't been requested, we'll need to NAK */ 618 switch (peer & MPPE_OPT_BITMASK) { 619 case MPPE_OPT_128BIT: 620 case MPPE_OPT_56BIT: 621 case MPPE_OPT_40BIT: 622 break; 623 default: 624 res = MODE_NAK; 625 } 626 627 /* Suggest the best number of bits */ 628 mval &= ~MPPE_OPT_BITMASK; 629 if (peer & MPPE_OPT_128BIT) 630 mval |= MPPE_OPT_128BIT; 631 else if (peer & MPPE_OPT_56BIT) 632 mval |= MPPE_OPT_56BIT; 633 else if (peer & MPPE_OPT_40BIT) 634 mval |= MPPE_OPT_40BIT; 635 else 636 mval |= MPPE_OPT_128BIT; 637 ua_htonl(&mval, o->data); 638 639 return res; 640 } 641 642 static struct mppe_state * 643 MPPE_InitState(struct fsm_opt *o) 644 { 645 struct mppe_state *mp; 646 u_int32_t val; 647 648 if ((mp = calloc(1, sizeof *mp)) != NULL) { 649 ua_ntohl(o->data, &val); 650 651 switch (val & MPPE_OPT_BITMASK) { 652 case MPPE_OPT_128BIT: 653 mp->keylen = 16; 654 mp->keybits = 128; 655 break; 656 case MPPE_OPT_56BIT: 657 mp->keylen = 8; 658 mp->keybits = 56; 659 break; 660 case MPPE_OPT_40BIT: 661 mp->keylen = 8; 662 mp->keybits = 40; 663 break; 664 default: 665 log_Printf(LogWARN, "Unexpected MPPE options 0x%08x\n", val); 666 free(mp); 667 return NULL; 668 } 669 670 mp->stateless = !!(val & MPPE_OPT_STATELESS); 671 } 672 673 return mp; 674 } 675 676 static void * 677 MPPEInitInput(struct bundle *bundle, struct fsm_opt *o) 678 { 679 struct mppe_state *mip; 680 681 if (!MPPE_MasterKeyValid) { 682 log_Printf(LogWARN, "MPPE: Cannot initialise without CHAP81\n"); 683 return NULL; 684 } 685 686 if ((mip = MPPE_InitState(o)) == NULL) { 687 log_Printf(LogWARN, "MPPEInput: Cannot initialise - unexpected options\n"); 688 return NULL; 689 } 690 691 log_Printf(LogDEBUG, "MPPE: InitInput: %d-bits\n", mip->keybits); 692 693 #ifndef NORADIUS 694 if (*bundle->radius.cfg.file && bundle->radius.mppe.recvkey) { 695 if (mip->keylen > bundle->radius.mppe.recvkeylen) 696 mip->keylen = bundle->radius.mppe.recvkeylen; 697 if (mip->keylen > sizeof mip->mastkey) 698 mip->keylen = sizeof mip->mastkey; 699 memcpy(mip->mastkey, bundle->radius.mppe.recvkey, mip->keylen); 700 } else 701 #endif 702 GetAsymetricStartKey(MPPE_MasterKey, mip->mastkey, mip->keylen, 0, 703 MPPE_IsServer); 704 705 GetNewKeyFromSHA(mip->mastkey, mip->mastkey, mip->keylen, mip->sesskey); 706 707 MPPEReduceSessionKey(mip); 708 709 log_Printf(LogCCP, "MPPE: Input channel initiated\n"); 710 711 if (!mip->stateless) { 712 /* 713 * We need to initialise our dictionary here as the first packet we 714 * receive is unlikely to have the FLUSHED bit set. 715 */ 716 log_Printf(LogDEBUG, "MPPEInitInput: Dictionary initialised [%d]\n", 717 mip->cohnum); 718 RC4_set_key(&mip->rc4key, mip->keylen, mip->sesskey); 719 } else { 720 /* 721 * We do the first key change here as the first packet is expected 722 * to have a sequence number of 0 and we'll therefore not expect 723 * to have to change the key at that point. 724 */ 725 log_Printf(LogDEBUG, "MPPEInitInput: Key changed [%d]\n", mip->cohnum); 726 MPPEKeyChange(mip); 727 } 728 729 return mip; 730 } 731 732 static void * 733 MPPEInitOutput(struct bundle *bundle, struct fsm_opt *o) 734 { 735 struct mppe_state *mop; 736 737 if (!MPPE_MasterKeyValid) { 738 log_Printf(LogWARN, "MPPE: Cannot initialise without CHAP81\n"); 739 return NULL; 740 } 741 742 if ((mop = MPPE_InitState(o)) == NULL) { 743 log_Printf(LogWARN, "MPPEOutput: Cannot initialise - unexpected options\n"); 744 return NULL; 745 } 746 747 log_Printf(LogDEBUG, "MPPE: InitOutput: %d-bits\n", mop->keybits); 748 749 #ifndef NORADIUS 750 if (*bundle->radius.cfg.file && bundle->radius.mppe.sendkey) { 751 if (mop->keylen > bundle->radius.mppe.sendkeylen) 752 mop->keylen = bundle->radius.mppe.sendkeylen; 753 if (mop->keylen > sizeof mop->mastkey) 754 mop->keylen = sizeof mop->mastkey; 755 memcpy(mop->mastkey, bundle->radius.mppe.sendkey, mop->keylen); 756 } else 757 #endif 758 GetAsymetricStartKey(MPPE_MasterKey, mop->mastkey, mop->keylen, 1, 759 MPPE_IsServer); 760 761 GetNewKeyFromSHA(mop->mastkey, mop->mastkey, mop->keylen, mop->sesskey); 762 763 MPPEReduceSessionKey(mop); 764 765 log_Printf(LogCCP, "MPPE: Output channel initiated\n"); 766 767 if (!mop->stateless) { 768 /* 769 * We need to initialise our dictionary now as the first packet we 770 * send won't have the FLUSHED bit set. 771 */ 772 log_Printf(LogDEBUG, "MPPEInitOutput: Dictionary initialised [%d]\n", 773 mop->cohnum); 774 RC4_set_key(&mop->rc4key, mop->keylen, mop->sesskey); 775 } 776 777 return mop; 778 } 779 780 static void 781 MPPETermInput(void *v) 782 { 783 free(v); 784 } 785 786 static void 787 MPPETermOutput(void *v) 788 { 789 free(v); 790 } 791 792 const struct ccp_algorithm MPPEAlgorithm = { 793 TY_MPPE, 794 CCP_NEG_MPPE, 795 MPPEDispOpts, 796 MPPEUsable, 797 MPPERequired, 798 { 799 MPPESetOptsInput, 800 MPPEInitInput, 801 MPPETermInput, 802 MPPEResetInput, 803 MPPEInput, 804 MPPEDictSetup 805 }, 806 { 807 2, 808 MPPEInitOptsOutput, 809 MPPESetOptsOutput, 810 MPPEInitOutput, 811 MPPETermOutput, 812 MPPEResetOutput, 813 MPPEOutput 814 }, 815 }; 816