/mandos/trunk : revision 745

40

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

41

42

#include <stdio.h> /* fprintf(), stderr, fwrite(),

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

45

#include <stddef.h> /* NULL, size_t, ssize_t */

46

#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

57

#include <sys/socket.h> /* socket(), struct sockaddr_in6,

58

inet_pton(), connect(),

59

getnameinfo() */

60

#include <fcntl.h> /* open() */

60

#include <fcntl.h> /* open(), unlinkat() */

61

#include <dirent.h> /* opendir(), struct dirent, readdir()

62

*/

63

#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

73

*/

74

#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

75

getuid(), getgid(), seteuid(),

76

setgid(), pause(), _exit() */

76

setgid(), pause(), _exit(),

77

unlinkat() */

77

78

#include <arpa/inet.h> /* inet_pton(), htons() */

78

79

#include <iso646.h> /* not, or, and */

79

80

#include <argp.h> /* struct argp_option, error_t, struct

233

234

.af = af };

234

235

if(new_server->ip == NULL){

235

236

perror_plus("strdup");

237

free(new_server);

236

238

return false;

237

239

}

238

240

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

239

241

if(ret == -1){

240

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

free((char *)(new_server->ip));

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

241

252

return false;

242

253

}

243

254

/* Special case of first server */

482

493

return plaintext_length;

483

494

}

484

495

496

__attribute__((warn_unused_result, const))

497

static const char *safe_string(const char *str){

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

485

503

__attribute__((warn_unused_result))

486

504

static const char *safer_gnutls_strerror(int value){

487

505

const char *ret = gnutls_strerror(value);

488

if(ret == NULL)

489

ret = "(unknown)";

490

return ret;

506

return safe_string(ret);

491

507

}

492

508

493

509

/* GnuTLS log function callback */

502

518

const char *seckeyfilename,

503

519

mandos_context *mc){

504

520

int ret;

521

unsigned int uret;

505

522

506

523

if(debug){

507

524

fprintf_plus(stderr, "Initializing GnuTLS\n");

558

575

safer_gnutls_strerror(ret));

559

576

goto globalfail;

560

577

}

578

if(mc->dh_bits == 0){

579

/* Find out the optimal number of DH bits */

580

/* Try to read the private key file */

581

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

buffer_capacity = incbuffer((char **)&buffer.data,

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

/* If successful, use buffer to parse private key */

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

" GnuTLS security parameter \"%s\".\n",

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

663

" implies %u DH bits; using that.\n",

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

fprintf_plus(stderr, "Failed to get implied number of DH"

670

" bits for security parameter \"%s\"): %s\n",

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

677

mc->dh_bits);

678

}

561

679

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

562

680

if(ret != GNUTLS_E_SUCCESS){

563

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

564

safer_gnutls_strerror(ret));

681

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

565

683

goto globalfail;

566

684

}

567

685

1065

1183

timed out */

1066

1184

1067

1185

if(quit_now){

1186

avahi_s_service_resolver_free(r);

1068

1187

return;

1069

1188

}

1070

1189

1346

1465

return 0;

1347

1466

}

1348

1467

1349

char *fullname = NULL;

1350

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1351

if(ret < 0){

1352

perror_plus("asprintf");

1353

return 0;

1354

}

1355

1356

ret = stat(fullname, &st);

1468

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1357

1469

if(ret == -1){

1358

1470

if(debug){

1359

1471

perror_plus("Could not stat hook");

1360

1472

}

1361

1473

return 0;

1362

1474

}

1363

free(fullname);

1364

1475

if(not (S_ISREG(st.st_mode))){

1365

1476

/* Not a regular file */

1366

1477

if(debug){

1465

1576

error_t ret_errno = 0;

1466

1577

if(seteuid(0) == -1){

1467

1578

ret_errno = errno;

1468

perror_plus("seteuid");

1469

1579

}

1470

1580

errno = old_errno;

1471

1581

return ret_errno;

1482

1592

}

1483

1593

if(setuid(0) == -1){

1484

1594

ret_errno = errno;

1485

perror_plus("seteuid");

1486

1595

}

1487

1596

errno = old_errno;

1488

1597

return ret_errno;

1495

1604

error_t ret_errno = 0;

1496

1605

if(seteuid(uid) == -1){

1497

1606

ret_errno = errno;

1498

perror_plus("seteuid");

1499

1607

}

1500

1608

errno = old_errno;

1501

1609

return ret_errno;

1508

1616

error_t ret_errno = 0;

1509

1617

if(setuid(uid) == -1){

1510

1618

ret_errno = errno;

1511

perror_plus("setuid");

1512

1619

}

1513

1620

errno = old_errno;

1514

1621

return ret_errno;

1515

1622

}

1516

1623

1517

#ifndef O_CLOEXEC

1518

/*

1519

* Based on the example in the GNU LibC manual chapter 13.13 "File

1520

* Descriptor Flags".

1521

| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |

1522

*/

1523

__attribute__((warn_unused_result))

1524

static int set_cloexec_flag(int fd){

1525

int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));

1526

/* If reading the flags failed, return error indication now. */

1527

if(ret < 0){

1528

return ret;

1529

}

1530

/* Store modified flag word in the descriptor. */

1531

return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,

1532

ret | FD_CLOEXEC));

1533

}

1534

#endif /* not O_CLOEXEC */

1535

1536

1624

__attribute__((nonnull))

1537

1625

void run_network_hooks(const char *mode, const char *interface,

1538

1626

const float delay){

1539

struct dirent **direntries;

1627

struct dirent **direntries = NULL;

1540

1628

if(hookdir_fd == -1){

1541

hookdir_fd = open(hookdir, O_RDONLY |

1542

#ifdef O_CLOEXEC

1543

O_CLOEXEC

1544

#else /* not O_CLOEXEC */

1545

0

1546

#endif /* not O_CLOEXEC */

1547

);

1629

hookdir_fd = open(hookdir, O_RDONLY);

1548

1630

if(hookdir_fd == -1){

1549

1631

if(errno == ENOENT){

1550

1632

if(debug){

1556

1638

}

1557

1639

return;

1558

1640

}

1559

#ifndef O_CLOEXEC

1560

if(set_cloexec_flag(hookdir_fd) < 0){

1561

perror_plus("set_cloexec_flag");

1562

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

1563

perror_plus("close");

1564

} else {

1565

hookdir_fd = -1;

1566

}

1567

return;

1568

}

1569

#endif /* not O_CLOEXEC */

1570

1641

}

1571

1642

#ifdef __GLIBC__

1572

1643

#if __GLIBC_PREREQ(2, 15)

1597

1668

if(hook_pid == 0){

1598

1669

/* Child */

1599

1670

/* Raise privileges */

1600

if(raise_privileges_permanently() != 0){

1671

errno = raise_privileges_permanently();

1672

if(errno != 0){

1601

1673

perror_plus("Failed to raise privileges");

1602

1674

_exit(EX_NOPERM);

1603

1675

}

1670

1742

_exit(EX_OSERR);

1671

1743

}

1672

1744

}

1673

if(fexecve(hookdir_fd, (char *const [])

1674

{ direntry->d_name, NULL }, environ) == -1){

1745

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

1746

if(hook_fd == -1){

1747

perror_plus("openat");

1748

_exit(EXIT_FAILURE);

1749

}

1750

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

1751

perror_plus("close");

1752

_exit(EXIT_FAILURE);

1753

}

1754

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

1755

environ) == -1){

1675

1756

perror_plus("fexecve");

1676

1757

_exit(EXIT_FAILURE);

1677

1758

}

1678

1759

} else {

1760

if(hook_pid == -1){

1761

perror_plus("fork");

1762

free(direntry);

1763

continue;

1764

}

1679

1765

int status;

1680

1766

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1681

1767

perror_plus("waitpid");

1768

free(direntry);

1682

1769

continue;

1683

1770

}

1684

1771

if(WIFEXITED(status)){

1686

1773

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1687

1774

" with status %d\n", direntry->d_name,

1688

1775

WEXITSTATUS(status));

1776

free(direntry);

1689

1777

continue;

1690

1778

}

1691

1779

} else if(WIFSIGNALED(status)){

1692

1780

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1693

1781

" signal %d\n", direntry->d_name,

1694

1782

WTERMSIG(status));

1783

free(direntry);

1695

1784

continue;

1696

1785

} else {

1697

1786

fprintf_plus(stderr, "Warning: network hook \"%s\""

1698

1787

" crashed\n", direntry->d_name);

1788

free(direntry);

1699

1789

continue;

1700

1790

}

1701

1791

}

1703

1793

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1704

1794

direntry->d_name);

1705

1795

}

1796

free(direntry);

1706

1797

}

1798

free(direntries);

1707

1799

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

1708

1800

perror_plus("close");

1709

1801

} else {

1766

1858

/* Raise privileges */

1767

1859

ret_errno = raise_privileges();

1768

1860

if(ret_errno != 0){

1861

errno = ret_errno;

1769

1862

perror_plus("Failed to raise privileges");

1770

1863

}

1771

1864

1875

1968

/* Raise privileges */

1876

1969

ret_errno = raise_privileges();

1877

1970

if(ret_errno != 0){

1971

errno = ret_errno;

1878

1972

perror_plus("Failed to raise privileges");

1879

1973

}

1880

1974

1913

2007

}

1914

2008

1915

2009

int main(int argc, char *argv[]){

1916

mandos_context mc = { .server = NULL, .dh_bits = 1024,

2010

mandos_context mc = { .server = NULL, .dh_bits = 0,

1917

2011

.priority = "SECURE256:!CTYPE-X.509:"

1918

"+CTYPE-OPENPGP", .current_server = NULL,

2012

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

1919

2013

.interfaces = NULL, .interfaces_size = 0 };

1920

2014

AvahiSServiceBrowser *sb = NULL;

1921

2015

error_t ret_errno;

2287

2381

2288

2382

/* If no interfaces were specified, make a list */

2289

2383

if(mc.interfaces == NULL){

2290

struct dirent **direntries;

2384

struct dirent **direntries = NULL;

2291

2385

/* Look for any good interfaces */

2292

2386

ret = scandir(sys_class_net, &direntries, good_interface,

2293

2387

alphasort);

2299

2393

if(ret_errno != 0){

2300

2394

errno = ret_errno;

2301

2395

perror_plus("argz_add");

2396

free(direntries[i]);

2302

2397

continue;

2303

2398

}

2304

2399

if(debug){

2305

2400

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2306

2401

direntries[i]->d_name);

2307

2402

}

2403

free(direntries[i]);

2308

2404

}

2309

2405

free(direntries);

2310

2406

} else {

2311

free(direntries);

2407

if(ret == 0){

2408

free(direntries);

2409

}

2312

2410

fprintf_plus(stderr, "Could not find a network interface\n");

2313

2411

exitcode = EXIT_FAILURE;

2314

2412

goto end;

2578

2676

mc.current_server->prev->next = NULL;

2579

2677

while(mc.current_server != NULL){

2580

2678

server *next = mc.current_server->next;

2679

#ifdef __GNUC__

2680

#pragma GCC diagnostic push

2681

#pragma GCC diagnostic ignored "-Wcast-qual"

2682

#endif

2683

free((char *)(mc.current_server->ip));

2684

#ifdef __GNUC__

2685

#pragma GCC diagnostic pop

2686

#endif

2581

2687

free(mc.current_server);

2582

2688

mc.current_server = next;

2583

2689

}

2587

2693

{

2588

2694

ret_errno = raise_privileges();

2589

2695

if(ret_errno != 0){

2696

errno = ret_errno;

2590

2697

perror_plus("Failed to raise privileges");

2591

2698

} else {

2592

2699

2615

2722

2616

2723

ret_errno = lower_privileges_permanently();

2617

2724

if(ret_errno != 0){

2725

errno = ret_errno;

2618

2726

perror_plus("Failed to lower privileges permanently");

2619

2727

}

2620

2728

}

2625

2733

/* Removes the GPGME temp directory and all files inside */

2626

2734

if(tempdir != NULL){

2627

2735

struct dirent **direntries = NULL;

2628

struct dirent *direntry = NULL;

2629

int numentries = scandir(tempdir, &direntries, notdotentries,

2630

alphasort);

2631

if(numentries > 0){

2632

for(int i = 0; i < numentries; i++){

2633

direntry = direntries[i];

2634

char *fullname = NULL;

2635

ret = asprintf(&fullname, "%s/%s", tempdir,

2636

direntry->d_name);

2637

if(ret < 0){

2638

perror_plus("asprintf");

2639

continue;

2640

}

2641

ret = remove(fullname);

2642

if(ret == -1){

2643

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2644

strerror(errno));

2645

}

2646

free(fullname);

2736

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |

2737

O_NOFOLLOW));

2738

if(tempdir_fd == -1){

2739

perror_plus("open");

2740

} else {

2741

#ifdef __GLIBC__

2742

#if __GLIBC_PREREQ(2, 15)

2743

int numentries = scandirat(tempdir_fd, ".", &direntries,

2744

notdotentries, alphasort);

2745

#else /* not __GLIBC_PREREQ(2, 15) */

2746

int numentries = scandir(tempdir, &direntries, notdotentries,

2747

alphasort);

2748

#endif /* not __GLIBC_PREREQ(2, 15) */

2749

#else /* not __GLIBC__ */

2750

int numentries = scandir(tempdir, &direntries, notdotentries,

2751

alphasort);

2752

#endif /* not __GLIBC__ */

2753

if(numentries >= 0){

2754

for(int i = 0; i < numentries; i++){

2755

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2756

if(ret == -1){

2757

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2758

" \"%s\", 0): %s\n", tempdir,

2759

direntries[i]->d_name, strerror(errno));

2760

}

2761

free(direntries[i]);

2762

}

2763

2764

/* need to clean even if 0 because man page doesn't specify */

2765

free(direntries);

2766

if(numentries == -1){

2767

perror_plus("scandir");

2768

}

2769

ret = rmdir(tempdir);

2770

if(ret == -1 and errno != ENOENT){

2771

perror_plus("rmdir");

2772

}

2647

2773

}

2648

}

2649

2650

/* need to clean even if 0 because man page doesn't specify */

2651

free(direntries);

2652

if(numentries == -1){

2653

perror_plus("scandir");

2654

}

2655

ret = rmdir(tempdir);

2656

if(ret == -1 and errno != ENOENT){

2657

perror_plus("rmdir");

2774

TEMP_FAILURE_RETRY(close(tempdir_fd));

2658

2775

}

2659

2776

}

2660

2777