/mandos/trunk : revision 692

40

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

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

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(), unlinkat() */

60

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

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(),

77

unlinkat() */

76

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

78

77

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

79

78

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

80

79

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

234

233

.af = af };

235

234

if(new_server->ip == NULL){

236

235

perror_plus("strdup");

237

free(new_server);

238

236

return false;

239

237

}

240

238

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

241

239

if(ret == -1){

242

240

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);

252

241

return false;

253

242

}

254

243

/* Special case of first server */

493

482

return plaintext_length;

494

483

}

495

484

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

503

485

__attribute__((warn_unused_result))

504

486

static const char *safer_gnutls_strerror(int value){

505

487

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

488

if(ret == NULL)

489

ret = "(unknown)";

490

return ret;

507

491

}

508

492

509

493

/* GnuTLS log function callback */

518

502

const char *seckeyfilename,

519

503

mandos_context *mc){

520

504

int ret;

521

unsigned int uret;

522

505

523

506

if(debug){

524

507

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

575

558

safer_gnutls_strerror(ret));

576

559

goto globalfail;

577

560

}

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

}

679

561

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

680

562

if(ret != GNUTLS_E_SUCCESS){

681

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

682

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

563

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

564

safer_gnutls_strerror(ret));

683

565

goto globalfail;

684

566

}

685

567

1183

1065

timed out */

1184

1066

1185

1067

if(quit_now){

1186

avahi_s_service_resolver_free(r);

1187

1068

return;

1188

1069

}

1189

1070

1465

1346

return 0;

1466

1347

}

1467

1348

1468

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

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);

1469

1357

if(ret == -1){

1470

1358

if(debug){

1471

1359

perror_plus("Could not stat hook");

1472

1360

}

1473

1361

return 0;

1474

1362

}

1363

free(fullname);

1475

1364

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

1476

1365

/* Not a regular file */

1477

1366

if(debug){

1576

1465

error_t ret_errno = 0;

1577

1466

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

1578

1467

ret_errno = errno;

1468

perror_plus("seteuid");

1579

1469

}

1580

1470

errno = old_errno;

1581

1471

return ret_errno;

1592

1482

}

1593

1483

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

1594

1484

ret_errno = errno;

1485

perror_plus("seteuid");

1595

1486

}

1596

1487

errno = old_errno;

1597

1488

return ret_errno;

1604

1495

error_t ret_errno = 0;

1605

1496

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

1606

1497

ret_errno = errno;

1498

perror_plus("seteuid");

1607

1499

}

1608

1500

errno = old_errno;

1609

1501

return ret_errno;

1616

1508

error_t ret_errno = 0;

1617

1509

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

1618

1510

ret_errno = errno;

1511

perror_plus("setuid");

1619

1512

}

1620

1513

errno = old_errno;

1621

1514

return ret_errno;

1622

1515

}

1623

1516

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

1624

1536

__attribute__((nonnull))

1625

1537

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

1626

1538

const float delay){

1627

struct dirent **direntries = NULL;

1539

struct dirent **direntries;

1628

1540

if(hookdir_fd == -1){

1629

hookdir_fd = open(hookdir, O_RDONLY);

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

);

1630

1548

if(hookdir_fd == -1){

1631

1549

if(errno == ENOENT){

1632

1550

if(debug){

1638

1556

}

1639

1557

return;

1640

1558

}

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 */

1641

1570

}

1642

1571

#ifdef __GLIBC__

1643

1572

#if __GLIBC_PREREQ(2, 15)

1668

1597

if(hook_pid == 0){

1669

1598

/* Child */

1670

1599

/* Raise privileges */

1671

errno = raise_privileges_permanently();

1672

if(errno != 0){

1600

if(raise_privileges_permanently() != 0){

1673

1601

perror_plus("Failed to raise privileges");

1674

1602

_exit(EX_NOPERM);

1675

1603

}

1742

1670

_exit(EX_OSERR);

1743

1671

}

1744

1672

}

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){

1673

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

1674

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

1756

1675

perror_plus("fexecve");

1757

1676

_exit(EXIT_FAILURE);

1758

1677

}

1759

1678

} else {

1760

if(hook_pid == -1){

1761

perror_plus("fork");

1762

free(direntry);

1763

continue;

1764

}

1765

1679

int status;

1766

1680

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

1767

1681

perror_plus("waitpid");

1768

free(direntry);

1769

1682

continue;

1770

1683

}

1771

1684

if(WIFEXITED(status)){

1773

1686

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

1774

1687

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

1775

1688

WEXITSTATUS(status));

1776

free(direntry);

1777

1689

continue;

1778

1690

}

1779

1691

} else if(WIFSIGNALED(status)){

1780

1692

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

1781

1693

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

1782

1694

WTERMSIG(status));

1783

free(direntry);

1784

1695

continue;

1785

1696

} else {

1786

1697

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

1787

1698

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

1788

free(direntry);

1789

1699

continue;

1790

1700

}

1791

1701

}

1793

1703

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

1794

1704

direntry->d_name);

1795

1705

}

1796

free(direntry);

1797

1706

}

1798

free(direntries);

1799

1707

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

1800

1708

perror_plus("close");

1801

1709

} else {

1858

1766

/* Raise privileges */

1859

1767

ret_errno = raise_privileges();

1860

1768

if(ret_errno != 0){

1861

errno = ret_errno;

1862

1769

perror_plus("Failed to raise privileges");

1863

1770

}

1864

1771

1968

1875

/* Raise privileges */

1969

1876

ret_errno = raise_privileges();

1970

1877

if(ret_errno != 0){

1971

errno = ret_errno;

1972

1878

perror_plus("Failed to raise privileges");

1973

1879

}

1974

1880

2007

1913

}

2008

1914

2009

1915

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

2010

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

1916

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

2011

1917

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

2012

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

1918

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

2013

1919

.interfaces = NULL, .interfaces_size = 0 };

2014

1920

AvahiSServiceBrowser *sb = NULL;

2015

1921

error_t ret_errno;

2381

2287

2382

2288

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

2383

2289

if(mc.interfaces == NULL){

2384

struct dirent **direntries = NULL;

2290

struct dirent **direntries;

2385

2291

/* Look for any good interfaces */

2386

2292

ret = scandir(sys_class_net, &direntries, good_interface,

2387

2293

alphasort);

2393

2299

if(ret_errno != 0){

2394

2300

errno = ret_errno;

2395

2301

perror_plus("argz_add");

2396

free(direntries[i]);

2397

2302

continue;

2398

2303

}

2399

2304

if(debug){

2400

2305

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

2401

2306

direntries[i]->d_name);

2402

2307

}

2403

free(direntries[i]);

2404

2308

}

2405

2309

free(direntries);

2406

2310

} else {

2407

if(ret == 0){

2408

free(direntries);

2409

}

2311

free(direntries);

2410

2312

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

2411

2313

exitcode = EXIT_FAILURE;

2412

2314

goto end;

2676

2578

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

2677

2579

while(mc.current_server != NULL){

2678

2580

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

2687

2581

free(mc.current_server);

2688

2582

mc.current_server = next;

2689

2583

}

2693

2587

{

2694

2588

ret_errno = raise_privileges();

2695

2589

if(ret_errno != 0){

2696

errno = ret_errno;

2697

2590

perror_plus("Failed to raise privileges");

2698

2591

} else {

2699

2592

2722

2615

2723

2616

ret_errno = lower_privileges_permanently();

2724

2617

if(ret_errno != 0){

2725

errno = ret_errno;

2726

2618

perror_plus("Failed to lower privileges permanently");

2727

2619

}

2728

2620

}

2733

2625

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

2734

2626

if(tempdir != NULL){

2735

2627

struct dirent **direntries = NULL;

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

}

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);

2773

2647

}

2774

TEMP_FAILURE_RETRY(close(tempdir_fd));

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");

2775

2658

}

2776

2659

}

2777

2660