1: /*
2: * Program to generate cryptographic keys for ntp clients and servers
3: *
4: * This program generates password encrypted data files for use with the
5: * Autokey security protocol and Network Time Protocol Version 4. Files
6: * are prefixed with a header giving the name and date of creation
7: * followed by a type-specific descriptive label and PEM-encoded data
8: * structure compatible with programs of the OpenSSL library.
9: *
10: * All file names are like "ntpkey_<type>_<hostname>.<filestamp>", where
11: * <type> is the file type, <hostname> the generating host name and
12: * <filestamp> the generation time in NTP seconds. The NTP programs
13: * expect generic names such as "ntpkey_<type>_whimsy.udel.edu" with the
14: * association maintained by soft links. Following is a list of file
15: * types; the first line is the file name and the second link name.
16: *
17: * ntpkey_MD5key_<hostname>.<filestamp>
18: * MD5 (128-bit) keys used to compute message digests in symmetric
19: * key cryptography
20: *
21: * ntpkey_RSAhost_<hostname>.<filestamp>
22: * ntpkey_host_<hostname>
23: * RSA private/public host key pair used for public key signatures
24: *
25: * ntpkey_RSAsign_<hostname>.<filestamp>
26: * ntpkey_sign_<hostname>
27: * RSA private/public sign key pair used for public key signatures
28: *
29: * ntpkey_DSAsign_<hostname>.<filestamp>
30: * ntpkey_sign_<hostname>
31: * DSA Private/public sign key pair used for public key signatures
32: *
33: * Available digest/signature schemes
34: *
35: * RSA: RSA-MD2, RSA-MD5, RSA-SHA, RSA-SHA1, RSA-MDC2, EVP-RIPEMD160
36: * DSA: DSA-SHA, DSA-SHA1
37: *
38: * ntpkey_XXXcert_<hostname>.<filestamp>
39: * ntpkey_cert_<hostname>
40: * X509v3 certificate using RSA or DSA public keys and signatures.
41: * XXX is a code identifying the message digest and signature
42: * encryption algorithm
43: *
44: * Identity schemes. The key type par is used for the challenge; the key
45: * type key is used for the response.
46: *
47: * ntpkey_IFFkey_<groupname>.<filestamp>
48: * ntpkey_iffkey_<groupname>
49: * Schnorr (IFF) identity parameters and keys
50: *
51: * ntpkey_GQkey_<groupname>.<filestamp>,
52: * ntpkey_gqkey_<groupname>
53: * Guillou-Quisquater (GQ) identity parameters and keys
54: *
55: * ntpkey_MVkeyX_<groupname>.<filestamp>,
56: * ntpkey_mvkey_<groupname>
57: * Mu-Varadharajan (MV) identity parameters and keys
58: *
59: * Note: Once in a while because of some statistical fluke this program
60: * fails to generate and verify some cryptographic data, as indicated by
61: * exit status -1. In this case simply run the program again. If the
62: * program does complete with exit code 0, the data are correct as
63: * verified.
64: *
65: * These cryptographic routines are characterized by the prime modulus
66: * size in bits. The default value of 512 bits is a compromise between
67: * cryptographic strength and computing time and is ordinarily
68: * considered adequate for this application. The routines have been
69: * tested with sizes of 256, 512, 1024 and 2048 bits. Not all message
70: * digest and signature encryption schemes work with sizes less than 512
71: * bits. The computing time for sizes greater than 2048 bits is
72: * prohibitive on all but the fastest processors. An UltraSPARC Blade
73: * 1000 took something over nine minutes to generate and verify the
74: * values with size 2048. An old SPARC IPC would take a week.
75: *
76: * The OpenSSL library used by this program expects a random seed file.
77: * As described in the OpenSSL documentation, the file name defaults to
78: * first the RANDFILE environment variable in the user's home directory
79: * and then .rnd in the user's home directory.
80: */
81: #ifdef HAVE_CONFIG_H
82: # include <config.h>
83: #endif
84: #include <string.h>
85: #include <stdio.h>
86: #include <stdlib.h>
87: #include <unistd.h>
88: #include <sys/stat.h>
89: #include <sys/time.h>
90: #include <sys/types.h>
91: #include "ntp_types.h"
92: #include "ntp_random.h"
93: #include "ntp_stdlib.h"
94: #include "ntp_assert.h"
95:
96: #include "ntp_libopts.h"
97: #include "ntp-keygen-opts.h"
98:
99: #ifdef OPENSSL
100: #include "openssl/bn.h"
101: #include "openssl/evp.h"
102: #include "openssl/err.h"
103: #include "openssl/rand.h"
104: #include "openssl/pem.h"
105: #include "openssl/x509v3.h"
106: #include <openssl/objects.h>
107: #endif /* OPENSSL */
108: #include <ssl_applink.c>
109:
110: /*
111: * Cryptodefines
112: */
113: #define MD5KEYS 10 /* number of keys generated of each type */
114: #define MD5SIZE 20 /* maximum key size */
115: #define JAN_1970 2208988800UL /* NTP seconds */
116: #define YEAR ((long)60*60*24*365) /* one year in seconds */
117: #define MAXFILENAME 256 /* max file name length */
118: #define MAXHOSTNAME 256 /* max host name length */
119: #ifdef OPENSSL
120: #define PLEN 512 /* default prime modulus size (bits) */
121: #define ILEN 256 /* default identity modulus size (bits) */
122: #define MVMAX 100 /* max MV parameters */
123:
124: /*
125: * Strings used in X509v3 extension fields
126: */
127: #define KEY_USAGE "digitalSignature,keyCertSign"
128: #define BASIC_CONSTRAINTS "critical,CA:TRUE"
129: #define EXT_KEY_PRIVATE "private"
130: #define EXT_KEY_TRUST "trustRoot"
131: #endif /* OPENSSL */
132:
133: /*
134: * Prototypes
135: */
136: FILE *fheader (const char *, const char *, const char *);
137: int gen_md5 (char *);
138: #ifdef OPENSSL
139: EVP_PKEY *gen_rsa (char *);
140: EVP_PKEY *gen_dsa (char *);
141: EVP_PKEY *gen_iffkey (char *);
142: EVP_PKEY *gen_gqkey (char *);
143: EVP_PKEY *gen_mvkey (char *, EVP_PKEY **);
144: void gen_mvserv (char *, EVP_PKEY **);
145: int x509 (EVP_PKEY *, const EVP_MD *, char *, char *,
146: char *);
147: void cb (int, int, void *);
148: EVP_PKEY *genkey (char *, char *);
149: EVP_PKEY *readkey (char *, char *, u_int *, EVP_PKEY **);
150: void writekey (char *, char *, u_int *, EVP_PKEY **);
151: u_long asn2ntp (ASN1_TIME *);
152: #endif /* OPENSSL */
153:
154: /*
155: * Program variables
156: */
157: extern char *optarg; /* command line argument */
158: char *progname;
159: volatile int debug = 0; /* debug, not de bug */
160: #ifdef OPENSSL
161: u_int modulus = PLEN; /* prime modulus size (bits) */
162: u_int modulus2 = ILEN; /* identity modulus size (bits) */
163: #endif
164: int nkeys; /* MV keys */
165: time_t epoch; /* Unix epoch (seconds) since 1970 */
166: u_int fstamp; /* NTP filestamp */
167: char *hostname = NULL; /* host name (subject name) */
168: char *groupname = NULL; /* trusted host name (issuer name) */
169: char filename[MAXFILENAME + 1]; /* file name */
170: char *passwd1 = NULL; /* input private key password */
171: char *passwd2 = NULL; /* output private key password */
172: #ifdef OPENSSL
173: long d0, d1, d2, d3; /* callback counters */
174: #endif /* OPENSSL */
175:
176: #ifdef SYS_WINNT
177: BOOL init_randfile();
178:
179: /*
180: * Don't try to follow symbolic links
181: */
182: int
183: readlink(char *link, char *file, int len)
184: {
185: return (-1);
186: }
187:
188: /*
189: * Don't try to create a symbolic link for now.
190: * Just move the file to the name you need.
191: */
192: int
193: symlink(char *filename, char *linkname) {
194: DeleteFile(linkname);
195: MoveFile(filename, linkname);
196: return (0);
197: }
198: void
199: InitWin32Sockets() {
200: WORD wVersionRequested;
201: WSADATA wsaData;
202: wVersionRequested = MAKEWORD(2,0);
203: if (WSAStartup(wVersionRequested, &wsaData))
204: {
205: fprintf(stderr, "No useable winsock.dll\n");
206: exit(1);
207: }
208: }
209: #endif /* SYS_WINNT */
210:
211: /*
212: * Main program
213: */
214: int
215: main(
216: int argc, /* command line options */
217: char **argv
218: )
219: {
220: struct timeval tv; /* initialization vector */
221: int md5key = 0; /* generate MD5 keys */
222: #ifdef OPENSSL
223: X509 *cert = NULL; /* X509 certificate */
224: X509_EXTENSION *ext; /* X509v3 extension */
225: EVP_PKEY *pkey_host = NULL; /* host key */
226: EVP_PKEY *pkey_sign = NULL; /* sign key */
227: EVP_PKEY *pkey_iffkey = NULL; /* IFF sever keys */
228: EVP_PKEY *pkey_gqkey = NULL; /* GQ server keys */
229: EVP_PKEY *pkey_mvkey = NULL; /* MV trusted agen keys */
230: EVP_PKEY *pkey_mvpar[MVMAX]; /* MV cleient keys */
231: int hostkey = 0; /* generate RSA keys */
232: int iffkey = 0; /* generate IFF keys */
233: int gqkey = 0; /* generate GQ keys */
234: int mvkey = 0; /* update MV keys */
235: int mvpar = 0; /* generate MV parameters */
236: char *sign = NULL; /* sign key */
237: EVP_PKEY *pkey = NULL; /* temp key */
238: const EVP_MD *ectx; /* EVP digest */
239: char pathbuf[MAXFILENAME + 1];
240: const char *scheme = NULL; /* digest/signature scheme */
241: char *exten = NULL; /* private extension */
242: char *grpkey = NULL; /* identity extension */
243: int nid; /* X509 digest/signature scheme */
244: FILE *fstr = NULL; /* file handle */
245: #define iffsw HAVE_OPT(ID_KEY)
246: #endif /* OPENSSL */
247: char hostbuf[MAXHOSTNAME + 1];
248: char groupbuf[MAXHOSTNAME + 1];
249:
250: progname = argv[0];
251:
252: #ifdef SYS_WINNT
253: /* Initialize before OpenSSL checks */
254: InitWin32Sockets();
255: if (!init_randfile())
256: fprintf(stderr, "Unable to initialize .rnd file\n");
257: ssl_applink();
258: #endif
259:
260: #ifdef OPENSSL
261: ssl_check_version();
262: #endif /* OPENSSL */
263:
264: /*
265: * Process options, initialize host name and timestamp.
266: */
267: gethostname(hostbuf, MAXHOSTNAME);
268: hostname = hostbuf;
269: gettimeofday(&tv, 0);
270:
271: epoch = tv.tv_sec;
272:
273: {
274: int optct = ntpOptionProcess(&ntp_keygenOptions,
275: argc, argv);
276: argc -= optct;
277: argv += optct;
278: }
279:
280: #ifdef OPENSSL
281: if (SSLeay() == SSLEAY_VERSION_NUMBER)
282: fprintf(stderr, "Using OpenSSL version %s\n",
283: SSLeay_version(SSLEAY_VERSION));
284: else
285: fprintf(stderr, "Built against OpenSSL %s, using version %s\n",
286: OPENSSL_VERSION_TEXT, SSLeay_version(SSLEAY_VERSION));
287: #endif /* OPENSSL */
288:
289: debug = DESC(DEBUG_LEVEL).optOccCt;
290: if (HAVE_OPT( MD5KEY ))
291: md5key++;
292:
293: #ifdef OPENSSL
294: passwd1 = hostbuf;
295: if (HAVE_OPT( PVT_PASSWD ))
296: passwd1 = strdup(OPT_ARG( PVT_PASSWD ));
297:
298: if (HAVE_OPT( GET_PVT_PASSWD ))
299: passwd2 = strdup(OPT_ARG( GET_PVT_PASSWD ));
300:
301: if (HAVE_OPT( HOST_KEY ))
302: hostkey++;
303:
304: if (HAVE_OPT( SIGN_KEY ))
305: sign = strdup(OPT_ARG( SIGN_KEY ));
306:
307: if (HAVE_OPT( GQ_PARAMS ))
308: gqkey++;
309:
310: if (HAVE_OPT( IFFKEY ))
311: iffkey++;
312:
313: if (HAVE_OPT( MV_PARAMS )) {
314: mvkey++;
315: nkeys = OPT_VALUE_MV_PARAMS;
316: }
317: if (HAVE_OPT( MV_KEYS )) {
318: mvpar++;
319: nkeys = OPT_VALUE_MV_KEYS;
320: }
321: if (HAVE_OPT( MODULUS ))
322: modulus = OPT_VALUE_MODULUS;
323:
324: if (HAVE_OPT( CERTIFICATE ))
325: scheme = OPT_ARG( CERTIFICATE );
326:
327: if (HAVE_OPT( SUBJECT_NAME ))
328: hostname = strdup(OPT_ARG( SUBJECT_NAME ));
329:
330: if (HAVE_OPT( ISSUER_NAME ))
331: groupname = strdup(OPT_ARG( ISSUER_NAME ));
332:
333: if (HAVE_OPT( PVT_CERT ))
334: exten = EXT_KEY_PRIVATE;
335:
336: if (HAVE_OPT( TRUSTED_CERT ))
337: exten = EXT_KEY_TRUST;
338:
339: /*
340: * Seed random number generator and grow weeds.
341: */
342: ERR_load_crypto_strings();
343: OpenSSL_add_all_algorithms();
344: if (!RAND_status()) {
345: u_int temp;
346:
347: if (RAND_file_name(pathbuf, MAXFILENAME) == NULL) {
348: fprintf(stderr, "RAND_file_name %s\n",
349: ERR_error_string(ERR_get_error(), NULL));
350: exit (-1);
351: }
352: temp = RAND_load_file(pathbuf, -1);
353: if (temp == 0) {
354: fprintf(stderr,
355: "RAND_load_file %s not found or empty\n",
356: pathbuf);
357: exit (-1);
358: }
359: fprintf(stderr,
360: "Random seed file %s %u bytes\n", pathbuf, temp);
361: RAND_add(&epoch, sizeof(epoch), 4.0);
362: }
363:
364: /*
365: * Load previous certificate if available.
366: */
367: sprintf(filename, "ntpkey_cert_%s", hostname);
368: if ((fstr = fopen(filename, "r")) != NULL) {
369: cert = PEM_read_X509(fstr, NULL, NULL, NULL);
370: fclose(fstr);
371: }
372: if (cert != NULL) {
373:
374: /*
375: * Extract subject name.
376: */
377: X509_NAME_oneline(X509_get_subject_name(cert), groupbuf,
378: MAXFILENAME);
379:
380: /*
381: * Extract digest/signature scheme.
382: */
383: if (scheme == NULL) {
384: nid = OBJ_obj2nid(cert->cert_info->
385: signature->algorithm);
386: scheme = OBJ_nid2sn(nid);
387: }
388:
389: /*
390: * If a key_usage extension field is present, determine
391: * whether this is a trusted or private certificate.
392: */
393: if (exten == NULL) {
394: BIO *bp;
395: int i, cnt;
396: char *ptr;
397:
398: ptr = strstr(groupbuf, "CN=");
399: cnt = X509_get_ext_count(cert);
400: for (i = 0; i < cnt; i++) {
401: ext = X509_get_ext(cert, i);
402: if (OBJ_obj2nid(ext->object) ==
403: NID_ext_key_usage) {
404: bp = BIO_new(BIO_s_mem());
405: X509V3_EXT_print(bp, ext, 0, 0);
406: BIO_gets(bp, pathbuf,
407: MAXFILENAME);
408: BIO_free(bp);
409: if (strcmp(pathbuf,
410: "Trust Root") == 0)
411: exten = EXT_KEY_TRUST;
412: else if (strcmp(pathbuf,
413: "Private") == 0)
414: exten = EXT_KEY_PRIVATE;
415: if (groupname == NULL)
416: groupname = ptr + 3;
417: }
418: }
419: }
420: }
421: if (scheme == NULL)
422: scheme = "RSA-MD5";
423: if (groupname == NULL)
424: groupname = hostname;
425: fprintf(stderr, "Using host %s group %s\n", hostname,
426: groupname);
427: if ((iffkey || gqkey || mvkey) && exten == NULL)
428: fprintf(stderr,
429: "Warning: identity files may not be useful with a nontrusted certificate.\n");
430: #endif /* OPENSSL */
431:
432: /*
433: * Create new unencrypted MD5 keys file if requested. If this
434: * option is selected, ignore all other options.
435: */
436: if (md5key) {
437: gen_md5("md5");
438: exit (0);
439: }
440:
441: #ifdef OPENSSL
442: /*
443: * Create a new encrypted RSA host key file if requested;
444: * otherwise, look for an existing host key file. If not found,
445: * create a new encrypted RSA host key file. If that fails, go
446: * no further.
447: */
448: if (hostkey)
449: pkey_host = genkey("RSA", "host");
450: if (pkey_host == NULL) {
451: sprintf(filename, "ntpkey_host_%s", hostname);
452: pkey_host = readkey(filename, passwd1, &fstamp, NULL);
453: if (pkey_host != NULL) {
454: readlink(filename, filename, sizeof(filename));
455: fprintf(stderr, "Using host key %s\n",
456: filename);
457: } else {
458: pkey_host = genkey("RSA", "host");
459: }
460: }
461: if (pkey_host == NULL) {
462: fprintf(stderr, "Generating host key fails\n");
463: exit (-1);
464: }
465:
466: /*
467: * Create new encrypted RSA or DSA sign keys file if requested;
468: * otherwise, look for an existing sign key file. If not found,
469: * use the host key instead.
470: */
471: if (sign != NULL)
472: pkey_sign = genkey(sign, "sign");
473: if (pkey_sign == NULL) {
474: sprintf(filename, "ntpkey_sign_%s", hostname);
475: pkey_sign = readkey(filename, passwd1, &fstamp, NULL);
476: if (pkey_sign != NULL) {
477: readlink(filename, filename, sizeof(filename));
478: fprintf(stderr, "Using sign key %s\n",
479: filename);
480: } else if (pkey_host != NULL) {
481: pkey_sign = pkey_host;
482: fprintf(stderr, "Using host key as sign key\n");
483: }
484: }
485:
486: /*
487: * Create new encrypted GQ server keys file if requested;
488: * otherwise, look for an exisiting file. If found, fetch the
489: * public key for the certificate.
490: */
491: if (gqkey)
492: pkey_gqkey = gen_gqkey("gqkey");
493: if (pkey_gqkey == NULL) {
494: sprintf(filename, "ntpkey_gqkey_%s", groupname);
495: pkey_gqkey = readkey(filename, passwd1, &fstamp, NULL);
496: if (pkey_gqkey != NULL) {
497: readlink(filename, filename, sizeof(filename));
498: fprintf(stderr, "Using GQ parameters %s\n",
499: filename);
500: }
501: }
502: if (pkey_gqkey != NULL)
503: grpkey = BN_bn2hex(pkey_gqkey->pkey.rsa->q);
504:
505: /*
506: * Write the nonencrypted GQ client parameters to the stdout
507: * stream. The parameter file is the server key file with the
508: * private key obscured.
509: */
510: if (pkey_gqkey != NULL && HAVE_OPT(ID_KEY)) {
511: RSA *rsa;
512:
513: epoch = fstamp - JAN_1970;
514: sprintf(filename, "ntpkey_gqpar_%s.%u", groupname,
515: fstamp);
516: fprintf(stderr, "Writing GQ parameters %s to stdout\n",
517: filename);
518: fprintf(stdout, "# %s\n# %s\n", filename,
519: ctime(&epoch));
520: rsa = pkey_gqkey->pkey.rsa;
521: BN_copy(rsa->p, BN_value_one());
522: BN_copy(rsa->q, BN_value_one());
523: pkey = EVP_PKEY_new();
524: EVP_PKEY_assign_RSA(pkey, rsa);
525: PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL,
526: NULL);
527: fclose(stdout);
528: if (debug)
529: RSA_print_fp(stderr, rsa, 0);
530: }
531:
532: /*
533: * Write the encrypted GQ server keys to the stdout stream.
534: */
535: if (pkey_gqkey != NULL && passwd2 != NULL) {
536: RSA *rsa;
537:
538: sprintf(filename, "ntpkey_gqkey_%s.%u", groupname,
539: fstamp);
540: fprintf(stderr, "Writing GQ keys %s to stdout\n",
541: filename);
542: fprintf(stdout, "# %s\n# %s\n", filename,
543: ctime(&epoch));
544: rsa = pkey_gqkey->pkey.rsa;
545: pkey = EVP_PKEY_new();
546: EVP_PKEY_assign_RSA(pkey, rsa);
547: PEM_write_PrivateKey(stdout, pkey,
548: EVP_des_cbc(), NULL, 0, NULL, passwd2);
549: fclose(stdout);
550: if (debug)
551: RSA_print_fp(stderr, rsa, 0);
552: }
553:
554: /*
555: * Create new encrypted IFF server keys file if requested;
556: * otherwise, look for existing file.
557: */
558: if (iffkey)
559: pkey_iffkey = gen_iffkey("iffkey");
560: if (pkey_iffkey == NULL) {
561: sprintf(filename, "ntpkey_iffkey_%s", groupname);
562: pkey_iffkey = readkey(filename, passwd1, &fstamp, NULL);
563: if (pkey_iffkey != NULL) {
564: readlink(filename, filename, sizeof(filename));
565: fprintf(stderr, "Using IFF keys %s\n",
566: filename);
567: }
568: }
569:
570: /*
571: * Write the nonencrypted IFF client parameters to the stdout
572: * stream. The parameter file is the server key file with the
573: * private key obscured.
574: */
575: if (pkey_iffkey != NULL && HAVE_OPT(ID_KEY)) {
576: DSA *dsa;
577:
578: epoch = fstamp - JAN_1970;
579: sprintf(filename, "ntpkey_iffpar_%s.%u", groupname,
580: fstamp);
581: fprintf(stderr, "Writing IFF parameters %s to stdout\n",
582: filename);
583: fprintf(stdout, "# %s\n# %s\n", filename,
584: ctime(&epoch));
585: dsa = pkey_iffkey->pkey.dsa;
586: BN_copy(dsa->priv_key, BN_value_one());
587: pkey = EVP_PKEY_new();
588: EVP_PKEY_assign_DSA(pkey, dsa);
589: PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL,
590: NULL);
591: fclose(stdout);
592: if (debug)
593: DSA_print_fp(stderr, dsa, 0);
594: }
595:
596: /*
597: * Write the encrypted IFF server keys to the stdout stream.
598: */
599: if (pkey_iffkey != NULL && passwd2 != NULL) {
600: DSA *dsa;
601:
602: epoch = fstamp - JAN_1970;
603: sprintf(filename, "ntpkey_iffkey_%s.%u", groupname,
604: fstamp);
605: fprintf(stderr, "Writing IFF keys %s to stdout\n",
606: filename);
607: fprintf(stdout, "# %s\n# %s\n", filename,
608: ctime(&epoch));
609: dsa = pkey_iffkey->pkey.dsa;
610: pkey = EVP_PKEY_new();
611: EVP_PKEY_assign_DSA(pkey, dsa);
612: PEM_write_PrivateKey(stdout, pkey, EVP_des_cbc(), NULL,
613: 0, NULL, passwd2);
614: fclose(stdout);
615: if (debug)
616: DSA_print_fp(stderr, dsa, 0);
617: }
618:
619: /*
620: * Create new encrypted MV trusted-authority keys file if
621: * requested; otherwise, look for existing keys file.
622: */
623: if (mvkey)
624: pkey_mvkey = gen_mvkey("mv", pkey_mvpar);
625: if (pkey_mvkey == NULL) {
626: sprintf(filename, "ntpkey_mvta_%s", groupname);
627: pkey_mvkey = readkey(filename, passwd1, &fstamp,
628: pkey_mvpar);
629: if (pkey_mvkey != NULL) {
630: readlink(filename, filename, sizeof(filename));
631: fprintf(stderr, "Using MV keys %s\n",
632: filename);
633: }
634: }
635:
636: /*
637: * Write the nonencrypted MV client parameters to the stdout
638: * stream. For the moment, we always use the client parameters
639: * associated with client key 1.
640: */
641: if (pkey_mvkey != NULL && HAVE_OPT(ID_KEY)) {
642: epoch = fstamp - JAN_1970;
643: sprintf(filename, "ntpkey_mvpar_%s.%u", groupname,
644: fstamp);
645: fprintf(stderr, "Writing MV parameters %s to stdout\n",
646: filename);
647: fprintf(stdout, "# %s\n# %s\n", filename,
648: ctime(&epoch));
649: pkey = pkey_mvpar[2];
650: PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL,
651: NULL);
652: fclose(stdout);
653: if (debug)
654: DSA_print_fp(stderr, pkey->pkey.dsa, 0);
655: }
656:
657: /*
658: * Write the encrypted MV server keys to the stdout stream.
659: */
660: if (pkey_mvkey != NULL && passwd2 != NULL) {
661: epoch = fstamp - JAN_1970;
662: sprintf(filename, "ntpkey_mvkey_%s.%u", groupname,
663: fstamp);
664: fprintf(stderr, "Writing MV keys %s to stdout\n",
665: filename);
666: fprintf(stdout, "# %s\n# %s\n", filename,
667: ctime(&epoch));
668: pkey = pkey_mvpar[1];
669: PEM_write_PrivateKey(stdout, pkey, EVP_des_cbc(), NULL,
670: 0, NULL, passwd2);
671: fclose(stdout);
672: if (debug)
673: DSA_print_fp(stderr, pkey->pkey.dsa, 0);
674: }
675:
676: /*
677: * Don't generate a certificate if no host keys or extracting
678: * encrypted or nonencrypted keys to the standard output stream.
679: */
680: if (pkey_host == NULL || HAVE_OPT(ID_KEY) || passwd2 != NULL)
681: exit (0);
682:
683: /*
684: * Decode the digest/signature scheme. If trusted, set the
685: * subject and issuer names to the group name; if not set both
686: * to the host name.
687: */
688: ectx = EVP_get_digestbyname(scheme);
689: if (ectx == NULL) {
690: fprintf(stderr,
691: "Invalid digest/signature combination %s\n",
692: scheme);
693: exit (-1);
694: }
695: if (exten == NULL)
696: x509(pkey_sign, ectx, grpkey, exten, hostname);
697: else
698: x509(pkey_sign, ectx, grpkey, exten, groupname);
699: #endif /* OPENSSL */
700: exit (0);
701: }
702:
703:
704: /*
705: * Generate semi-random MD5 keys compatible with NTPv3 and NTPv4. Also,
706: * if OpenSSL is around, generate random SHA1 keys compatible with
707: * symmetric key cryptography.
708: */
709: int
710: gen_md5(
711: char *id /* file name id */
712: )
713: {
714: u_char md5key[MD5SIZE + 1]; /* MD5 key */
715: FILE *str;
716: int i, j;
717: #ifdef OPENSSL
718: u_char keystr[MD5SIZE];
719: u_char hexstr[2 * MD5SIZE + 1];
720: u_char hex[] = "0123456789abcdef";
721: #endif /* OPENSSL */
722:
723: str = fheader("MD5key", id, groupname);
724: ntp_srandom((u_long)epoch);
725: for (i = 1; i <= MD5KEYS; i++) {
726: for (j = 0; j < MD5SIZE; j++) {
727: int temp;
728:
729: while (1) {
730: temp = ntp_random() & 0xff;
731: if (temp == '#')
732: continue;
733:
734: if (temp > 0x20 && temp < 0x7f)
735: break;
736: }
737: md5key[j] = (u_char)temp;
738: }
739: md5key[j] = '\0';
740: fprintf(str, "%2d MD5 %s # MD5 key\n", i,
741: md5key);
742: }
743: #ifdef OPENSSL
744: for (i = 1; i <= MD5KEYS; i++) {
745: RAND_bytes(keystr, 20);
746: for (j = 0; j < MD5SIZE; j++) {
747: hexstr[2 * j] = hex[keystr[j] >> 4];
748: hexstr[2 * j + 1] = hex[keystr[j] & 0xf];
749: }
750: hexstr[2 * MD5SIZE] = '\0';
751: fprintf(str, "%2d SHA1 %s # SHA1 key\n", i + MD5KEYS,
752: hexstr);
753: }
754: #endif /* OPENSSL */
755: fclose(str);
756: return (1);
757: }
758:
759:
760: #ifdef OPENSSL
761: /*
762: * readkey - load cryptographic parameters and keys
763: *
764: * This routine loads a PEM-encoded file of given name and password and
765: * extracts the filestamp from the file name. It returns a pointer to
766: * the first key if valid, NULL if not.
767: */
768: EVP_PKEY * /* public/private key pair */
769: readkey(
770: char *cp, /* file name */
771: char *passwd, /* password */
772: u_int *estamp, /* file stamp */
773: EVP_PKEY **evpars /* parameter list pointer */
774: )
775: {
776: FILE *str; /* file handle */
777: EVP_PKEY *pkey = NULL; /* public/private key */
778: u_int gstamp; /* filestamp */
779: char linkname[MAXFILENAME]; /* filestamp buffer) */
780: EVP_PKEY *parkey;
781: char *ptr;
782: int i;
783:
784: /*
785: * Open the key file.
786: */
787: str = fopen(cp, "r");
788: if (str == NULL)
789: return (NULL);
790:
791: /*
792: * Read the filestamp, which is contained in the first line.
793: */
794: if ((ptr = fgets(linkname, MAXFILENAME, str)) == NULL) {
795: fprintf(stderr, "Empty key file %s\n", cp);
796: fclose(str);
797: return (NULL);
798: }
799: if ((ptr = strrchr(ptr, '.')) == NULL) {
800: fprintf(stderr, "No filestamp found in %s\n", cp);
801: fclose(str);
802: return (NULL);
803: }
804: if (sscanf(++ptr, "%u", &gstamp) != 1) {
805: fprintf(stderr, "Invalid filestamp found in %s\n", cp);
806: fclose(str);
807: return (NULL);
808: }
809:
810: /*
811: * Read and decrypt PEM-encoded private keys. The first one
812: * found is returned. If others are expected, add them to the
813: * parameter list.
814: */
815: for (i = 0; i <= MVMAX - 1;) {
816: parkey = PEM_read_PrivateKey(str, NULL, NULL, passwd);
817: if (evpars != NULL) {
818: evpars[i++] = parkey;
819: evpars[i] = NULL;
820: }
821: if (parkey == NULL)
822: break;
823:
824: if (pkey == NULL)
825: pkey = parkey;
826: if (debug) {
827: if (parkey->type == EVP_PKEY_DSA)
828: DSA_print_fp(stderr, parkey->pkey.dsa,
829: 0);
830: else if (parkey->type == EVP_PKEY_RSA)
831: RSA_print_fp(stderr, parkey->pkey.rsa,
832: 0);
833: }
834: }
835: fclose(str);
836: if (pkey == NULL) {
837: fprintf(stderr, "Corrupt file %s or wrong key %s\n%s\n",
838: cp, passwd, ERR_error_string(ERR_get_error(),
839: NULL));
840: exit (-1);
841: }
842: *estamp = gstamp;
843: return (pkey);
844: }
845:
846:
847: /*
848: * Generate RSA public/private key pair
849: */
850: EVP_PKEY * /* public/private key pair */
851: gen_rsa(
852: char *id /* file name id */
853: )
854: {
855: EVP_PKEY *pkey; /* private key */
856: RSA *rsa; /* RSA parameters and key pair */
857: FILE *str;
858:
859: fprintf(stderr, "Generating RSA keys (%d bits)...\n", modulus);
860: rsa = RSA_generate_key(modulus, 3, cb, "RSA");
861: fprintf(stderr, "\n");
862: if (rsa == NULL) {
863: fprintf(stderr, "RSA generate keys fails\n%s\n",
864: ERR_error_string(ERR_get_error(), NULL));
865: return (NULL);
866: }
867:
868: /*
869: * For signature encryption it is not necessary that the RSA
870: * parameters be strictly groomed and once in a while the
871: * modulus turns out to be non-prime. Just for grins, we check
872: * the primality.
873: */
874: if (!RSA_check_key(rsa)) {
875: fprintf(stderr, "Invalid RSA key\n%s\n",
876: ERR_error_string(ERR_get_error(), NULL));
877: RSA_free(rsa);
878: return (NULL);
879: }
880:
881: /*
882: * Write the RSA parameters and keys as a RSA private key
883: * encoded in PEM.
884: */
885: if (strcmp(id, "sign") == 0)
886: str = fheader("RSAsign", id, hostname);
887: else
888: str = fheader("RSAhost", id, hostname);
889: pkey = EVP_PKEY_new();
890: EVP_PKEY_assign_RSA(pkey, rsa);
891: PEM_write_PrivateKey(str, pkey, EVP_des_cbc(), NULL, 0, NULL,
892: passwd1);
893: fclose(str);
894: if (debug)
895: RSA_print_fp(stderr, rsa, 0);
896: return (pkey);
897: }
898:
899:
900: /*
901: * Generate DSA public/private key pair
902: */
903: EVP_PKEY * /* public/private key pair */
904: gen_dsa(
905: char *id /* file name id */
906: )
907: {
908: EVP_PKEY *pkey; /* private key */
909: DSA *dsa; /* DSA parameters */
910: u_char seed[20]; /* seed for parameters */
911: FILE *str;
912:
913: /*
914: * Generate DSA parameters.
915: */
916: fprintf(stderr,
917: "Generating DSA parameters (%d bits)...\n", modulus);
918: RAND_bytes(seed, sizeof(seed));
919: dsa = DSA_generate_parameters(modulus, seed, sizeof(seed), NULL,
920: NULL, cb, "DSA");
921: fprintf(stderr, "\n");
922: if (dsa == NULL) {
923: fprintf(stderr, "DSA generate parameters fails\n%s\n",
924: ERR_error_string(ERR_get_error(), NULL));
925: return (NULL);
926: }
927:
928: /*
929: * Generate DSA keys.
930: */
931: fprintf(stderr, "Generating DSA keys (%d bits)...\n", modulus);
932: if (!DSA_generate_key(dsa)) {
933: fprintf(stderr, "DSA generate keys fails\n%s\n",
934: ERR_error_string(ERR_get_error(), NULL));
935: DSA_free(dsa);
936: return (NULL);
937: }
938:
939: /*
940: * Write the DSA parameters and keys as a DSA private key
941: * encoded in PEM.
942: */
943: str = fheader("DSAsign", id, hostname);
944: pkey = EVP_PKEY_new();
945: EVP_PKEY_assign_DSA(pkey, dsa);
946: PEM_write_PrivateKey(str, pkey, EVP_des_cbc(), NULL, 0, NULL,
947: passwd1);
948: fclose(str);
949: if (debug)
950: DSA_print_fp(stderr, dsa, 0);
951: return (pkey);
952: }
953:
954:
955: /*
956: ***********************************************************************
957: * *
958: * The following routines implement the Schnorr (IFF) identity scheme *
959: * *
960: ***********************************************************************
961: *
962: * The Schnorr (IFF) identity scheme is intended for use when
963: * certificates are generated by some other trusted certificate
964: * authority and the certificate cannot be used to convey public
965: * parameters. There are two kinds of files: encrypted server files that
966: * contain private and public values and nonencrypted client files that
967: * contain only public values. New generations of server files must be
968: * securely transmitted to all servers of the group; client files can be
969: * distributed by any means. The scheme is self contained and
970: * independent of new generations of host keys, sign keys and
971: * certificates.
972: *
973: * The IFF values hide in a DSA cuckoo structure which uses the same
974: * parameters. The values are used by an identity scheme based on DSA
975: * cryptography and described in Stimson p. 285. The p is a 512-bit
976: * prime, g a generator of Zp* and q a 160-bit prime that divides p - 1
977: * and is a qth root of 1 mod p; that is, g^q = 1 mod p. The TA rolls a
978: * private random group key b (0 < b < q) and public key v = g^b, then
979: * sends (p, q, g, b) to the servers and (p, q, g, v) to the clients.
980: * Alice challenges Bob to confirm identity using the protocol described
981: * below.
982: *
983: * How it works
984: *
985: * The scheme goes like this. Both Alice and Bob have the public primes
986: * p, q and generator g. The TA gives private key b to Bob and public
987: * key v to Alice.
988: *
989: * Alice rolls new random challenge r (o < r < q) and sends to Bob in
990: * the IFF request message. Bob rolls new random k (0 < k < q), then
991: * computes y = k + b r mod q and x = g^k mod p and sends (y, hash(x))
992: * to Alice in the response message. Besides making the response
993: * shorter, the hash makes it effectivey impossible for an intruder to
994: * solve for b by observing a number of these messages.
995: *
996: * Alice receives the response and computes g^y v^r mod p. After a bit
997: * of algebra, this simplifies to g^k. If the hash of this result
998: * matches hash(x), Alice knows that Bob has the group key b. The signed
999: * response binds this knowledge to Bob's private key and the public key
1000: * previously received in his certificate.
1001: */
1002: /*
1003: * Generate Schnorr (IFF) keys.
1004: */
1005: EVP_PKEY * /* DSA cuckoo nest */
1006: gen_iffkey(
1007: char *id /* file name id */
1008: )
1009: {
1010: EVP_PKEY *pkey; /* private key */
1011: DSA *dsa; /* DSA parameters */
1012: u_char seed[20]; /* seed for parameters */
1013: BN_CTX *ctx; /* BN working space */
1014: BIGNUM *b, *r, *k, *u, *v, *w; /* BN temp */
1015: FILE *str;
1016: u_int temp;
1017:
1018: /*
1019: * Generate DSA parameters for use as IFF parameters.
1020: */
1021: fprintf(stderr, "Generating IFF keys (%d bits)...\n",
1022: modulus2);
1023: RAND_bytes(seed, sizeof(seed));
1024: dsa = DSA_generate_parameters(modulus2, seed, sizeof(seed), NULL,
1025: NULL, cb, "IFF");
1026: fprintf(stderr, "\n");
1027: if (dsa == NULL) {
1028: fprintf(stderr, "DSA generate parameters fails\n%s\n",
1029: ERR_error_string(ERR_get_error(), NULL));
1030: return (NULL);;
1031: }
1032:
1033: /*
1034: * Generate the private and public keys. The DSA parameters and
1035: * private key are distributed to the servers, while all except
1036: * the private key are distributed to the clients.
1037: */
1038: b = BN_new(); r = BN_new(); k = BN_new();
1039: u = BN_new(); v = BN_new(); w = BN_new(); ctx = BN_CTX_new();
1040: BN_rand(b, BN_num_bits(dsa->q), -1, 0); /* a */
1041: BN_mod(b, b, dsa->q, ctx);
1042: BN_sub(v, dsa->q, b);
1043: BN_mod_exp(v, dsa->g, v, dsa->p, ctx); /* g^(q - b) mod p */
1044: BN_mod_exp(u, dsa->g, b, dsa->p, ctx); /* g^b mod p */
1045: BN_mod_mul(u, u, v, dsa->p, ctx);
1046: temp = BN_is_one(u);
1047: fprintf(stderr,
1048: "Confirm g^(q - b) g^b = 1 mod p: %s\n", temp == 1 ?
1049: "yes" : "no");
1050: if (!temp) {
1051: BN_free(b); BN_free(r); BN_free(k);
1052: BN_free(u); BN_free(v); BN_free(w); BN_CTX_free(ctx);
1053: return (NULL);
1054: }
1055: dsa->priv_key = BN_dup(b); /* private key */
1056: dsa->pub_key = BN_dup(v); /* public key */
1057:
1058: /*
1059: * Here is a trial round of the protocol. First, Alice rolls
1060: * random nonce r mod q and sends it to Bob. She needs only
1061: * q from parameters.
1062: */
1063: BN_rand(r, BN_num_bits(dsa->q), -1, 0); /* r */
1064: BN_mod(r, r, dsa->q, ctx);
1065:
1066: /*
1067: * Bob rolls random nonce k mod q, computes y = k + b r mod q
1068: * and x = g^k mod p, then sends (y, x) to Alice. He needs
1069: * p, q and b from parameters and r from Alice.
1070: */
1071: BN_rand(k, BN_num_bits(dsa->q), -1, 0); /* k, 0 < k < q */
1072: BN_mod(k, k, dsa->q, ctx);
1073: BN_mod_mul(v, dsa->priv_key, r, dsa->q, ctx); /* b r mod q */
1074: BN_add(v, v, k);
1075: BN_mod(v, v, dsa->q, ctx); /* y = k + b r mod q */
1076: BN_mod_exp(u, dsa->g, k, dsa->p, ctx); /* x = g^k mod p */
1077:
1078: /*
1079: * Alice verifies x = g^y v^r to confirm that Bob has group key
1080: * b. She needs p, q, g from parameters, (y, x) from Bob and the
1081: * original r. We omit the detail here thatt only the hash of y
1082: * is sent.
1083: */
1084: BN_mod_exp(v, dsa->g, v, dsa->p, ctx); /* g^y mod p */
1085: BN_mod_exp(w, dsa->pub_key, r, dsa->p, ctx); /* v^r */
1086: BN_mod_mul(v, w, v, dsa->p, ctx); /* product mod p */
1087: temp = BN_cmp(u, v);
1088: fprintf(stderr,
1089: "Confirm g^k = g^(k + b r) g^(q - b) r: %s\n", temp ==
1090: 0 ? "yes" : "no");
1091: BN_free(b); BN_free(r); BN_free(k);
1092: BN_free(u); BN_free(v); BN_free(w); BN_CTX_free(ctx);
1093: if (temp != 0) {
1094: DSA_free(dsa);
1095: return (NULL);
1096: }
1097:
1098: /*
1099: * Write the IFF keys as an encrypted DSA private key encoded in
1100: * PEM.
1101: *
1102: * p modulus p
1103: * q modulus q
1104: * g generator g
1105: * priv_key b
1106: * public_key v
1107: * kinv not used
1108: * r not used
1109: */
1110: str = fheader("IFFkey", id, groupname);
1111: pkey = EVP_PKEY_new();
1112: EVP_PKEY_assign_DSA(pkey, dsa);
1113: PEM_write_PrivateKey(str, pkey, EVP_des_cbc(), NULL, 0, NULL,
1114: passwd1);
1115: fclose(str);
1116: if (debug)
1117: DSA_print_fp(stderr, dsa, 0);
1118: return (pkey);
1119: }
1120:
1121:
1122: /*
1123: ***********************************************************************
1124: * *
1125: * The following routines implement the Guillou-Quisquater (GQ) *
1126: * identity scheme *
1127: * *
1128: ***********************************************************************
1129: *
1130: * The Guillou-Quisquater (GQ) identity scheme is intended for use when
1131: * the certificate can be used to convey public parameters. The scheme
1132: * uses a X509v3 certificate extension field do convey the public key of
1133: * a private key known only to servers. There are two kinds of files:
1134: * encrypted server files that contain private and public values and
1135: * nonencrypted client files that contain only public values. New
1136: * generations of server files must be securely transmitted to all
1137: * servers of the group; client files can be distributed by any means.
1138: * The scheme is self contained and independent of new generations of
1139: * host keys and sign keys. The scheme is self contained and independent
1140: * of new generations of host keys and sign keys.
1141: *
1142: * The GQ parameters hide in a RSA cuckoo structure which uses the same
1143: * parameters. The values are used by an identity scheme based on RSA
1144: * cryptography and described in Stimson p. 300 (with errors). The 512-
1145: * bit public modulus is n = p q, where p and q are secret large primes.
1146: * The TA rolls private random group key b as RSA exponent. These values
1147: * are known to all group members.
1148: *
1149: * When rolling new certificates, a server recomputes the private and
1150: * public keys. The private key u is a random roll, while the public key
1151: * is the inverse obscured by the group key v = (u^-1)^b. These values
1152: * replace the private and public keys normally generated by the RSA
1153: * scheme. Alice challenges Bob to confirm identity using the protocol
1154: * described below.
1155: *
1156: * How it works
1157: *
1158: * The scheme goes like this. Both Alice and Bob have the same modulus n
1159: * and some random b as the group key. These values are computed and
1160: * distributed in advance via secret means, although only the group key
1161: * b is truly secret. Each has a private random private key u and public
1162: * key (u^-1)^b, although not necessarily the same ones. Bob and Alice
1163: * can regenerate the key pair from time to time without affecting
1164: * operations. The public key is conveyed on the certificate in an
1165: * extension field; the private key is never revealed.
1166: *
1167: * Alice rolls new random challenge r and sends to Bob in the GQ
1168: * request message. Bob rolls new random k, then computes y = k u^r mod
1169: * n and x = k^b mod n and sends (y, hash(x)) to Alice in the response
1170: * message. Besides making the response shorter, the hash makes it
1171: * effectivey impossible for an intruder to solve for b by observing
1172: * a number of these messages.
1173: *
1174: * Alice receives the response and computes y^b v^r mod n. After a bit
1175: * of algebra, this simplifies to k^b. If the hash of this result
1176: * matches hash(x), Alice knows that Bob has the group key b. The signed
1177: * response binds this knowledge to Bob's private key and the public key
1178: * previously received in his certificate.
1179: */
1180: /*
1181: * Generate Guillou-Quisquater (GQ) parameters file.
1182: */
1183: EVP_PKEY * /* RSA cuckoo nest */
1184: gen_gqkey(
1185: char *id /* file name id */
1186: )
1187: {
1188: EVP_PKEY *pkey; /* private key */
1189: RSA *rsa; /* RSA parameters */
1190: BN_CTX *ctx; /* BN working space */
1191: BIGNUM *u, *v, *g, *k, *r, *y; /* BN temps */
1192: FILE *str;
1193: u_int temp;
1194:
1195: /*
1196: * Generate RSA parameters for use as GQ parameters.
1197: */
1198: fprintf(stderr,
1199: "Generating GQ parameters (%d bits)...\n",
1200: modulus2);
1201: rsa = RSA_generate_key(modulus2, 3, cb, "GQ");
1202: fprintf(stderr, "\n");
1203: if (rsa == NULL) {
1204: fprintf(stderr, "RSA generate keys fails\n%s\n",
1205: ERR_error_string(ERR_get_error(), NULL));
1206: return (NULL);
1207: }
1208: ctx = BN_CTX_new(); u = BN_new(); v = BN_new();
1209: g = BN_new(); k = BN_new(); r = BN_new(); y = BN_new();
1210:
1211: /*
1212: * Generate the group key b, which is saved in the e member of
1213: * the RSA structure. The group key is transmitted to each group
1214: * member encrypted by the member private key.
1215: */
1216: ctx = BN_CTX_new();
1217: BN_rand(rsa->e, BN_num_bits(rsa->n), -1, 0); /* b */
1218: BN_mod(rsa->e, rsa->e, rsa->n, ctx);
1219:
1220: /*
1221: * When generating his certificate, Bob rolls random private key
1222: * u, then computes inverse v = u^-1.
1223: */
1224: BN_rand(u, BN_num_bits(rsa->n), -1, 0); /* u */
1225: BN_mod(u, u, rsa->n, ctx);
1226: BN_mod_inverse(v, u, rsa->n, ctx); /* u^-1 mod n */
1227: BN_mod_mul(k, v, u, rsa->n, ctx);
1228:
1229: /*
1230: * Bob computes public key v = (u^-1)^b, which is saved in an
1231: * extension field on his certificate. We check that u^b v =
1232: * 1 mod n.
1233: */
1234: BN_mod_exp(v, v, rsa->e, rsa->n, ctx);
1235: BN_mod_exp(g, u, rsa->e, rsa->n, ctx); /* u^b */
1236: BN_mod_mul(g, g, v, rsa->n, ctx); /* u^b (u^-1)^b */
1237: temp = BN_is_one(g);
1238: fprintf(stderr,
1239: "Confirm u^b (u^-1)^b = 1 mod n: %s\n", temp ? "yes" :
1240: "no");
1241: if (!temp) {
1242: BN_free(u); BN_free(v);
1243: BN_free(g); BN_free(k); BN_free(r); BN_free(y);
1244: BN_CTX_free(ctx);
1245: RSA_free(rsa);
1246: return (NULL);
1247: }
1248: BN_copy(rsa->p, u); /* private key */
1249: BN_copy(rsa->q, v); /* public key */
1250:
1251: /*
1252: * Here is a trial run of the protocol. First, Alice rolls
1253: * random nonce r mod n and sends it to Bob. She needs only n
1254: * from parameters.
1255: */
1256: BN_rand(r, BN_num_bits(rsa->n), -1, 0); /* r */
1257: BN_mod(r, r, rsa->n, ctx);
1258:
1259: /*
1260: * Bob rolls random nonce k mod n, computes y = k u^r mod n and
1261: * g = k^b mod n, then sends (y, g) to Alice. He needs n, u, b
1262: * from parameters and r from Alice.
1263: */
1264: BN_rand(k, BN_num_bits(rsa->n), -1, 0); /* k */
1265: BN_mod(k, k, rsa->n, ctx);
1266: BN_mod_exp(y, rsa->p, r, rsa->n, ctx); /* u^r mod n */
1267: BN_mod_mul(y, k, y, rsa->n, ctx); /* y = k u^r mod n */
1268: BN_mod_exp(g, k, rsa->e, rsa->n, ctx); /* g = k^b mod n */
1269:
1270: /*
1271: * Alice verifies g = v^r y^b mod n to confirm that Bob has
1272: * private key u. She needs n, g from parameters, public key v =
1273: * (u^-1)^b from the certificate, (y, g) from Bob and the
1274: * original r. We omit the detaul here that only the hash of g
1275: * is sent.
1276: */
1277: BN_mod_exp(v, rsa->q, r, rsa->n, ctx); /* v^r mod n */
1278: BN_mod_exp(y, y, rsa->e, rsa->n, ctx); /* y^b mod n */
1279: BN_mod_mul(y, v, y, rsa->n, ctx); /* v^r y^b mod n */
1280: temp = BN_cmp(y, g);
1281: fprintf(stderr, "Confirm g^k = v^r y^b mod n: %s\n", temp == 0 ?
1282: "yes" : "no");
1283: BN_CTX_free(ctx); BN_free(u); BN_free(v);
1284: BN_free(g); BN_free(k); BN_free(r); BN_free(y);
1285: if (temp != 0) {
1286: RSA_free(rsa);
1287: return (NULL);
1288: }
1289:
1290: /*
1291: * Write the GQ parameter file as an encrypted RSA private key
1292: * encoded in PEM.
1293: *
1294: * n modulus n
1295: * e group key b
1296: * d not used
1297: * p private key u
1298: * q public key (u^-1)^b
1299: * dmp1 not used
1300: * dmq1 not used
1301: * iqmp not used
1302: */
1303: BN_copy(rsa->d, BN_value_one());
1304: BN_copy(rsa->dmp1, BN_value_one());
1305: BN_copy(rsa->dmq1, BN_value_one());
1306: BN_copy(rsa->iqmp, BN_value_one());
1307: str = fheader("GQkey", id, groupname);
1308: pkey = EVP_PKEY_new();
1309: EVP_PKEY_assign_RSA(pkey, rsa);
1310: PEM_write_PrivateKey(str, pkey, EVP_des_cbc(), NULL, 0, NULL,
1311: passwd1);
1312: fclose(str);
1313: if (debug)
1314: RSA_print_fp(stderr, rsa, 0);
1315: return (pkey);
1316: }
1317:
1318:
1319: /*
1320: ***********************************************************************
1321: * *
1322: * The following routines implement the Mu-Varadharajan (MV) identity *
1323: * scheme *
1324: * *
1325: ***********************************************************************
1326: *
1327: * The Mu-Varadharajan (MV) cryptosystem was originally intended when
1328: * servers broadcast messages to clients, but clients never send
1329: * messages to servers. There is one encryption key for the server and a
1330: * separate decryption key for each client. It operated something like a
1331: * pay-per-view satellite broadcasting system where the session key is
1332: * encrypted by the broadcaster and the decryption keys are held in a
1333: * tamperproof set-top box.
1334: *
1335: * The MV parameters and private encryption key hide in a DSA cuckoo
1336: * structure which uses the same parameters, but generated in a
1337: * different way. The values are used in an encryption scheme similar to
1338: * El Gamal cryptography and a polynomial formed from the expansion of
1339: * product terms (x - x[j]), as described in Mu, Y., and V.
1340: * Varadharajan: Robust and Secure Broadcasting, Proc. Indocrypt 2001,
1341: * 223-231. The paper has significant errors and serious omissions.
1342: *
1343: * Let q be the product of n distinct primes s1[j] (j = 1...n), where
1344: * each s1[j] has m significant bits. Let p be a prime p = 2 * q + 1, so
1345: * that q and each s1[j] divide p - 1 and p has M = n * m + 1
1346: * significant bits. Let g be a generator of Zp; that is, gcd(g, p - 1)
1347: * = 1 and g^q = 1 mod p. We do modular arithmetic over Zq and then
1348: * project into Zp* as exponents of g. Sometimes we have to compute an
1349: * inverse b^-1 of random b in Zq, but for that purpose we require
1350: * gcd(b, q) = 1. We expect M to be in the 500-bit range and n
1351: * relatively small, like 30. These are the parameters of the scheme and
1352: * they are expensive to compute.
1353: *
1354: * We set up an instance of the scheme as follows. A set of random
1355: * values x[j] mod q (j = 1...n), are generated as the zeros of a
1356: * polynomial of order n. The product terms (x - x[j]) are expanded to
1357: * form coefficients a[i] mod q (i = 0...n) in powers of x. These are
1358: * used as exponents of the generator g mod p to generate the private
1359: * encryption key A. The pair (gbar, ghat) of public server keys and the
1360: * pairs (xbar[j], xhat[j]) (j = 1...n) of private client keys are used
1361: * to construct the decryption keys. The devil is in the details.
1362: *
1363: * This routine generates a private server encryption file including the
1364: * private encryption key E and partial decryption keys gbar and ghat.
1365: * It then generates public client decryption files including the public
1366: * keys xbar[j] and xhat[j] for each client j. The partial decryption
1367: * files are used to compute the inverse of E. These values are suitably
1368: * blinded so secrets are not revealed.
1369: *
1370: * The distinguishing characteristic of this scheme is the capability to
1371: * revoke keys. Included in the calculation of E, gbar and ghat is the
1372: * product s = prod(s1[j]) (j = 1...n) above. If the factor s1[j] is
1373: * subsequently removed from the product and E, gbar and ghat
1374: * recomputed, the jth client will no longer be able to compute E^-1 and
1375: * thus unable to decrypt the messageblock.
1376: *
1377: * How it works
1378: *
1379: * The scheme goes like this. Bob has the server values (p, E, q, gbar,
1380: * ghat) and Alice has the client values (p, xbar, xhat).
1381: *
1382: * Alice rolls new random nonce r mod p and sends to Bob in the MV
1383: * request message. Bob rolls random nonce k mod q, encrypts y = r E^k
1384: * mod p and sends (y, gbar^k, ghat^k) to Alice.
1385: *
1386: * Alice receives the response and computes the inverse (E^k)^-1 from
1387: * the partial decryption keys gbar^k, ghat^k, xbar and xhat. She then
1388: * decrypts y and verifies it matches the original r. The signed
1389: * response binds this knowledge to Bob's private key and the public key
1390: * previously received in his certificate.
1391: */
1392: EVP_PKEY * /* DSA cuckoo nest */
1393: gen_mvkey(
1394: char *id, /* file name id */
1395: EVP_PKEY **evpars /* parameter list pointer */
1396: )
1397: {
1398: EVP_PKEY *pkey, *pkey1; /* private keys */
1399: DSA *dsa, *dsa2, *sdsa; /* DSA parameters */
1400: BN_CTX *ctx; /* BN working space */
1401: BIGNUM *a[MVMAX]; /* polynomial coefficient vector */
1402: BIGNUM *g[MVMAX]; /* public key vector */
1403: BIGNUM *s1[MVMAX]; /* private enabling keys */
1404: BIGNUM *x[MVMAX]; /* polynomial zeros vector */
1405: BIGNUM *xbar[MVMAX], *xhat[MVMAX]; /* private keys vector */
1406: BIGNUM *b; /* group key */
1407: BIGNUM *b1; /* inverse group key */
1408: BIGNUM *s; /* enabling key */
1409: BIGNUM *biga; /* master encryption key */
1410: BIGNUM *bige; /* session encryption key */
1411: BIGNUM *gbar, *ghat; /* public key */
1412: BIGNUM *u, *v, *w; /* BN scratch */
1413: int i, j, n;
1414: FILE *str;
1415: u_int temp;
1416:
1417: /*
1418: * Generate MV parameters.
1419: *
1420: * The object is to generate a multiplicative group Zp* modulo a
1421: * prime p and a subset Zq mod q, where q is the product of n
1422: * distinct primes s1[j] (j = 1...n) and q divides p - 1. We
1423: * first generate n m-bit primes, where the product n m is in
1424: * the order of 512 bits. One or more of these may have to be
1425: * replaced later. As a practical matter, it is tough to find
1426: * more than 31 distinct primes for 512 bits or 61 primes for
1427: * 1024 bits. The latter can take several hundred iterations
1428: * and several minutes on a Sun Blade 1000.
1429: */
1430: n = nkeys;
1431: fprintf(stderr,
1432: "Generating MV parameters for %d keys (%d bits)...\n", n,
1433: modulus2 / n);
1434: ctx = BN_CTX_new(); u = BN_new(); v = BN_new(); w = BN_new();
1435: b = BN_new(); b1 = BN_new();
1436: dsa = DSA_new();
1437: dsa->p = BN_new(); dsa->q = BN_new(); dsa->g = BN_new();
1438: dsa->priv_key = BN_new(); dsa->pub_key = BN_new();
1439: temp = 0;
1440: for (j = 1; j <= n; j++) {
1441: s1[j] = BN_new();
1442: while (1) {
1443: BN_generate_prime(s1[j], modulus2 / n, 0, NULL,
1444: NULL, NULL, NULL);
1445: for (i = 1; i < j; i++) {
1446: if (BN_cmp(s1[i], s1[j]) == 0)
1447: break;
1448: }
1449: if (i == j)
1450: break;
1451: temp++;
1452: }
1453: }
1454: fprintf(stderr, "Birthday keys regenerated %d\n", temp);
1455:
1456: /*
1457: * Compute the modulus q as the product of the primes. Compute
1458: * the modulus p as 2 * q + 1 and test p for primality. If p
1459: * is composite, replace one of the primes with a new distinct
1460: * one and try again. Note that q will hardly be a secret since
1461: * we have to reveal p to servers, but not clients. However,
1462: * factoring q to find the primes should be adequately hard, as
1463: * this is the same problem considered hard in RSA. Question: is
1464: * it as hard to find n small prime factors totalling n bits as
1465: * it is to find two large prime factors totalling n bits?
1466: * Remember, the bad guy doesn't know n.
1467: */
1468: temp = 0;
1469: while (1) {
1470: BN_one(dsa->q);
1471: for (j = 1; j <= n; j++)
1472: BN_mul(dsa->q, dsa->q, s1[j], ctx);
1473: BN_copy(dsa->p, dsa->q);
1474: BN_add(dsa->p, dsa->p, dsa->p);
1475: BN_add_word(dsa->p, 1);
1476: if (BN_is_prime(dsa->p, BN_prime_checks, NULL, ctx,
1477: NULL))
1478: break;
1479:
1480: temp++;
1481: j = temp % n + 1;
1482: while (1) {
1483: BN_generate_prime(u, modulus2 / n, 0, 0, NULL,
1484: NULL, NULL);
1485: for (i = 1; i <= n; i++) {
1486: if (BN_cmp(u, s1[i]) == 0)
1487: break;
1488: }
1489: if (i > n)
1490: break;
1491: }
1492: BN_copy(s1[j], u);
1493: }
1494: fprintf(stderr, "Defective keys regenerated %d\n", temp);
1495:
1496: /*
1497: * Compute the generator g using a random roll such that
1498: * gcd(g, p - 1) = 1 and g^q = 1. This is a generator of p, not
1499: * q. This may take several iterations.
1500: */
1501: BN_copy(v, dsa->p);
1502: BN_sub_word(v, 1);
1503: while (1) {
1504: BN_rand(dsa->g, BN_num_bits(dsa->p) - 1, 0, 0);
1505: BN_mod(dsa->g, dsa->g, dsa->p, ctx);
1506: BN_gcd(u, dsa->g, v, ctx);
1507: if (!BN_is_one(u))
1508: continue;
1509:
1510: BN_mod_exp(u, dsa->g, dsa->q, dsa->p, ctx);
1511: if (BN_is_one(u))
1512: break;
1513: }
1514:
1515: /*
1516: * Setup is now complete. Roll random polynomial roots x[j]
1517: * (j = 1...n) for all j. While it may not be strictly
1518: * necessary, Make sure each root has no factors in common with
1519: * q.
1520: */
1521: fprintf(stderr,
1522: "Generating polynomial coefficients for %d roots (%d bits)\n",
1523: n, BN_num_bits(dsa->q));
1524: for (j = 1; j <= n; j++) {
1525: x[j] = BN_new();
1526:
1527: while (1) {
1528: BN_rand(x[j], BN_num_bits(dsa->q), 0, 0);
1529: BN_mod(x[j], x[j], dsa->q, ctx);
1530: BN_gcd(u, x[j], dsa->q, ctx);
1531: if (BN_is_one(u))
1532: break;
1533: }
1534: }
1535:
1536: /*
1537: * Generate polynomial coefficients a[i] (i = 0...n) from the
1538: * expansion of root products (x - x[j]) mod q for all j. The
1539: * method is a present from Charlie Boncelet.
1540: */
1541: for (i = 0; i <= n; i++) {
1542: a[i] = BN_new();
1543:
1544: BN_one(a[i]);
1545: }
1546: for (j = 1; j <= n; j++) {
1547: BN_zero(w);
1548: for (i = 0; i < j; i++) {
1549: BN_copy(u, dsa->q);
1550: BN_mod_mul(v, a[i], x[j], dsa->q, ctx);
1551: BN_sub(u, u, v);
1552: BN_add(u, u, w);
1553: BN_copy(w, a[i]);
1554: BN_mod(a[i], u, dsa->q, ctx);
1555: }
1556: }
1557:
1558: /*
1559: * Generate g[i] = g^a[i] mod p for all i and the generator g.
1560: */
1561: for (i = 0; i <= n; i++) {
1562: g[i] = BN_new();
1563:
1564: BN_mod_exp(g[i], dsa->g, a[i], dsa->p, ctx);
1565: }
1566:
1567: /*
1568: * Verify prod(g[i]^(a[i] x[j]^i)) = 1 for all i, j. Note the
1569: * a[i] x[j]^i exponent is computed mod q, but the g[i] is
1570: * computed mod p. also note the expression given in the paper
1571: * is incorrect.
1572: */
1573: temp = 1;
1574: for (j = 1; j <= n; j++) {
1575: BN_one(u);
1576: for (i = 0; i <= n; i++) {
1577: BN_set_word(v, i);
1578: BN_mod_exp(v, x[j], v, dsa->q, ctx);
1579: BN_mod_mul(v, v, a[i], dsa->q, ctx);
1580: BN_mod_exp(v, dsa->g, v, dsa->p, ctx);
1581: BN_mod_mul(u, u, v, dsa->p, ctx);
1582: }
1583: if (!BN_is_one(u))
1584: temp = 0;
1585: }
1586: fprintf(stderr,
1587: "Confirm prod(g[i]^(x[j]^i)) = 1 for all i, j: %s\n", temp ?
1588: "yes" : "no");
1589: if (!temp) {
1590: return (NULL);
1591: }
1592:
1593: /*
1594: * Make private encryption key A. Keep it around for awhile,
1595: * since it is expensive to compute.
1596: */
1597: biga = BN_new();
1598:
1599: BN_one(biga);
1600: for (j = 1; j <= n; j++) {
1601: for (i = 0; i < n; i++) {
1602: BN_set_word(v, i);
1603: BN_mod_exp(v, x[j], v, dsa->q, ctx);
1604: BN_mod_exp(v, g[i], v, dsa->p, ctx);
1605: BN_mod_mul(biga, biga, v, dsa->p, ctx);
1606: }
1607: }
1608:
1609: /*
1610: * Roll private random group key b mod q (0 < b < q), where
1611: * gcd(b, q) = 1 to guarantee b^-1 exists, then compute b^-1
1612: * mod q. If b is changed, the client keys must be recomputed.
1613: */
1614: while (1) {
1615: BN_rand(b, BN_num_bits(dsa->q), 0, 0);
1616: BN_mod(b, b, dsa->q, ctx);
1617: BN_gcd(u, b, dsa->q, ctx);
1618: if (BN_is_one(u))
1619: break;
1620: }
1621: BN_mod_inverse(b1, b, dsa->q, ctx);
1622:
1623: /*
1624: * Make private client keys (xbar[j], xhat[j]) for all j. Note
1625: * that the keys for the jth client do not s1[j] or the product
1626: * s1[j]) (j = 1...n) which is q by construction.
1627: *
1628: * Compute the factor w such that w s1[j] = s1[j] for all j. The
1629: * easy way to do this is to compute (q + s1[j]) / s1[j].
1630: * Exercise for the student: prove the remainder is always zero.
1631: */
1632: for (j = 1; j <= n; j++) {
1633: xbar[j] = BN_new(); xhat[j] = BN_new();
1634:
1635: BN_add(w, dsa->q, s1[j]);
1636: BN_div(w, u, w, s1[j], ctx);
1637: BN_zero(xbar[j]);
1638: BN_set_word(v, n);
1639: for (i = 1; i <= n; i++) {
1640: if (i == j)
1641: continue;
1642: BN_mod_exp(u, x[i], v, dsa->q, ctx);
1643: BN_add(xbar[j], xbar[j], u);
1644: }
1645: BN_mod_mul(xbar[j], xbar[j], b1, dsa->q, ctx);
1646: BN_mod_exp(xhat[j], x[j], v, dsa->q, ctx);
1647: BN_mod_mul(xhat[j], xhat[j], w, dsa->q, ctx);
1648: }
1649:
1650: /*
1651: * We revoke client j by dividing q by s1[j]. The quotient
1652: * becomes the enabling key s. Note we always have to revoke
1653: * one key; otherwise, the plaintext and cryptotext would be
1654: * identical. For the present there are no provisions to revoke
1655: * additional keys, so we sail on with only token revocations.
1656: */
1657: s = BN_new();
1658:
1659: BN_copy(s, dsa->q);
1660: BN_div(s, u, s, s1[n], ctx);
1661:
1662: /*
1663: * For each combination of clients to be revoked, make private
1664: * encryption key E = A^s and partial decryption keys gbar = g^s
1665: * and ghat = g^(s b), all mod p. The servers use these keys to
1666: * compute the session encryption key and partial decryption
1667: * keys. These values must be regenerated if the enabling key is
1668: * changed.
1669: */
1670: bige = BN_new(); gbar = BN_new(); ghat = BN_new();
1671:
1672: BN_mod_exp(bige, biga, s, dsa->p, ctx);
1673: BN_mod_exp(gbar, dsa->g, s, dsa->p, ctx);
1674: BN_mod_mul(v, s, b, dsa->q, ctx);
1675: BN_mod_exp(ghat, dsa->g, v, dsa->p, ctx);
1676:
1677: /*
1678: * Notes: We produce the key media in three steps. The first
1679: * step is to generate the system parameters p, q, g, b, A and
1680: * the enabling keys s1[j]. Associated with each s1[j] are
1681: * parameters xbar[j] and xhat[j]. All of these parameters are
1682: * retained in a data structure protecteted by the trusted-agent
1683: * password. The p, xbar[j] and xhat[j] paremeters are
1684: * distributed to the j clients. When the client keys are to be
1685: * activated, the enabled keys are multipied together to form
1686: * the master enabling key s. This and the other parameters are
1687: * used to compute the server encryption key E and the partial
1688: * decryption keys gbar and ghat.
1689: *
1690: * In the identity exchange the client rolls random r and sends
1691: * it to the server. The server rolls random k, which is used
1692: * only once, then computes the session key E^k and partial
1693: * decryption keys gbar^k and ghat^k. The server sends the
1694: * encrypted r along with gbar^k and ghat^k to the client. The
1695: * client completes the decryption and verifies it matches r.
1696: */
1697: /*
1698: * Write the MV trusted-agent parameters and keys as a DSA
1699: * private key encoded in PEM.
1700: *
1701: * p modulus p
1702: * q modulus q
1703: * g generator g
1704: * priv_key A mod p
1705: * pub_key b mod q
1706: * (remaining values are not used)
1707: */
1708: i = 0;
1709: str = fheader("MVta", "mvta", groupname);
1710: fprintf(stderr, "Generating MV trusted-authority keys\n");
1711: BN_copy(dsa->priv_key, biga);
1712: BN_copy(dsa->pub_key, b);
1713: pkey = EVP_PKEY_new();
1714: EVP_PKEY_assign_DSA(pkey, dsa);
1715: PEM_write_PrivateKey(str, pkey, EVP_des_cbc(), NULL, 0, NULL,
1716: passwd1);
1717: evpars[i++] = pkey;
1718: if (debug)
1719: DSA_print_fp(stderr, dsa, 0);
1720:
1721: /*
1722: * Append the MV server parameters and keys as a DSA key encoded
1723: * in PEM.
1724: *
1725: * p modulus p
1726: * q modulus q (used only when generating k)
1727: * g bige
1728: * priv_key gbar
1729: * pub_key ghat
1730: * (remaining values are not used)
1731: */
1732: fprintf(stderr, "Generating MV server keys\n");
1733: dsa2 = DSA_new();
1734: dsa2->p = BN_dup(dsa->p);
1735: dsa2->q = BN_dup(dsa->q);
1736: dsa2->g = BN_dup(bige);
1737: dsa2->priv_key = BN_dup(gbar);
1738: dsa2->pub_key = BN_dup(ghat);
1739: pkey1 = EVP_PKEY_new();
1740: EVP_PKEY_assign_DSA(pkey1, dsa2);
1741: PEM_write_PrivateKey(str, pkey1, EVP_des_cbc(), NULL, 0, NULL,
1742: passwd1);
1743: evpars[i++] = pkey1;
1744: if (debug)
1745: DSA_print_fp(stderr, dsa2, 0);
1746:
1747: /*
1748: * Append the MV client parameters for each client j as DSA keys
1749: * encoded in PEM.
1750: *
1751: * p modulus p
1752: * priv_key xbar[j] mod q
1753: * pub_key xhat[j] mod q
1754: * (remaining values are not used)
1755: */
1756: fprintf(stderr, "Generating %d MV client keys\n", n);
1757: for (j = 1; j <= n; j++) {
1758: sdsa = DSA_new();
1759:
1760: sdsa->p = BN_dup(dsa->p);
1761: sdsa->q = BN_dup(BN_value_one());
1762: sdsa->g = BN_dup(BN_value_one());
1763: sdsa->priv_key = BN_dup(xbar[j]);
1764: sdsa->pub_key = BN_dup(xhat[j]);
1765: pkey1 = EVP_PKEY_new();
1766: EVP_PKEY_set1_DSA(pkey1, sdsa);
1767: PEM_write_PrivateKey(str, pkey1, EVP_des_cbc(), NULL, 0,
1768: NULL, passwd1);
1769: evpars[i++] = pkey1;
1770: if (debug)
1771: DSA_print_fp(stderr, sdsa, 0);
1772:
1773: /*
1774: * The product gbar^k)^xbar[j] (ghat^k)^xhat[j] and E
1775: * are inverses of each other. We check that the product
1776: * is one for each client except the ones that have been
1777: * revoked.
1778: */
1779: BN_mod_exp(v, dsa2->priv_key, sdsa->pub_key, dsa->p,
1780: ctx);
1781: BN_mod_exp(u, dsa2->pub_key, sdsa->priv_key, dsa->p,
1782: ctx);
1783: BN_mod_mul(u, u, v, dsa->p, ctx);
1784: BN_mod_mul(u, u, bige, dsa->p, ctx);
1785: if (!BN_is_one(u)) {
1786: fprintf(stderr, "Revoke key %d\n", j);
1787: continue;
1788: }
1789: }
1790: evpars[i++] = NULL;
1791: fclose(str);
1792:
1793: /*
1794: * Free the countries.
1795: */
1796: for (i = 0; i <= n; i++) {
1797: BN_free(a[i]); BN_free(g[i]);
1798: }
1799: for (j = 1; j <= n; j++) {
1800: BN_free(x[j]); BN_free(xbar[j]); BN_free(xhat[j]);
1801: BN_free(s1[j]);
1802: }
1803: return (pkey);
1804: }
1805:
1806:
1807: /*
1808: * Generate X509v3 certificate.
1809: *
1810: * The certificate consists of the version number, serial number,
1811: * validity interval, issuer name, subject name and public key. For a
1812: * self-signed certificate, the issuer name is the same as the subject
1813: * name and these items are signed using the subject private key. The
1814: * validity interval extends from the current time to the same time one
1815: * year hence. For NTP purposes, it is convenient to use the NTP seconds
1816: * of the current time as the serial number.
1817: */
1818: int
1819: x509 (
1820: EVP_PKEY *pkey, /* generic signature algorithm */
1821: const EVP_MD *md, /* generic digest algorithm */
1822: char *gqpub, /* identity extension (hex string) */
1823: char *exten, /* private cert extension */
1824: char *name /* subject/issuer namd */
1825: )
1826: {
1827: X509 *cert; /* X509 certificate */
1828: X509_NAME *subj; /* distinguished (common) name */
1829: X509_EXTENSION *ex; /* X509v3 extension */
1830: FILE *str; /* file handle */
1831: ASN1_INTEGER *serial; /* serial number */
1832: const char *id; /* digest/signature scheme name */
1833: char pathbuf[MAXFILENAME + 1];
1834:
1835: /*
1836: * Generate X509 self-signed certificate.
1837: *
1838: * Set the certificate serial to the NTP seconds for grins. Set
1839: * the version to 3. Set the initial validity to the current
1840: * time and the finalvalidity one year hence.
1841: */
1842: id = OBJ_nid2sn(md->pkey_type);
1843: fprintf(stderr, "Generating new certificate %s %s\n", name, id);
1844: cert = X509_new();
1845: X509_set_version(cert, 2L);
1846: serial = ASN1_INTEGER_new();
1847: ASN1_INTEGER_set(serial, (long)epoch + JAN_1970);
1848: X509_set_serialNumber(cert, serial);
1849: ASN1_INTEGER_free(serial);
1850: X509_time_adj(X509_get_notBefore(cert), 0L, &epoch);
1851: X509_time_adj(X509_get_notAfter(cert), YEAR, &epoch);
1852: subj = X509_get_subject_name(cert);
1853: X509_NAME_add_entry_by_txt(subj, "commonName", MBSTRING_ASC,
1854: (unsigned char *) name, strlen(name), -1, 0);
1855: subj = X509_get_issuer_name(cert);
1856: X509_NAME_add_entry_by_txt(subj, "commonName", MBSTRING_ASC,
1857: (unsigned char *) name, strlen(name), -1, 0);
1858: if (!X509_set_pubkey(cert, pkey)) {
1859: fprintf(stderr, "Assign key fails\n%s\n",
1860: ERR_error_string(ERR_get_error(), NULL));
1861: X509_free(cert);
1862: return (0);
1863: }
1864:
1865: /*
1866: * Add X509v3 extensions if present. These represent the minimum
1867: * set defined in RFC3280 less the certificate_policy extension,
1868: * which is seriously obfuscated in OpenSSL.
1869: */
1870: /*
1871: * The basic_constraints extension CA:TRUE allows servers to
1872: * sign client certficitates.
1873: */
1874: fprintf(stderr, "%s: %s\n", LN_basic_constraints,
1875: BASIC_CONSTRAINTS);
1876: ex = X509V3_EXT_conf_nid(NULL, NULL, NID_basic_constraints,
1877: BASIC_CONSTRAINTS);
1878: if (!X509_add_ext(cert, ex, -1)) {
1879: fprintf(stderr, "Add extension field fails\n%s\n",
1880: ERR_error_string(ERR_get_error(), NULL));
1881: return (0);
1882: }
1883: X509_EXTENSION_free(ex);
1884:
1885: /*
1886: * The key_usage extension designates the purposes the key can
1887: * be used for.
1888: */
1889: fprintf(stderr, "%s: %s\n", LN_key_usage, KEY_USAGE);
1890: ex = X509V3_EXT_conf_nid(NULL, NULL, NID_key_usage, KEY_USAGE);
1891: if (!X509_add_ext(cert, ex, -1)) {
1892: fprintf(stderr, "Add extension field fails\n%s\n",
1893: ERR_error_string(ERR_get_error(), NULL));
1894: return (0);
1895: }
1896: X509_EXTENSION_free(ex);
1897: /*
1898: * The subject_key_identifier is used for the GQ public key.
1899: * This should not be controversial.
1900: */
1901: if (gqpub != NULL) {
1902: fprintf(stderr, "%s\n", LN_subject_key_identifier);
1903: ex = X509V3_EXT_conf_nid(NULL, NULL,
1904: NID_subject_key_identifier, gqpub);
1905: if (!X509_add_ext(cert, ex, -1)) {
1906: fprintf(stderr,
1907: "Add extension field fails\n%s\n",
1908: ERR_error_string(ERR_get_error(), NULL));
1909: return (0);
1910: }
1911: X509_EXTENSION_free(ex);
1912: }
1913:
1914: /*
1915: * The extended key usage extension is used for special purpose
1916: * here. The semantics probably do not conform to the designer's
1917: * intent and will likely change in future.
1918: *
1919: * "trustRoot" designates a root authority
1920: * "private" designates a private certificate
1921: */
1922: if (exten != NULL) {
1923: fprintf(stderr, "%s: %s\n", LN_ext_key_usage, exten);
1924: ex = X509V3_EXT_conf_nid(NULL, NULL,
1925: NID_ext_key_usage, exten);
1926: if (!X509_add_ext(cert, ex, -1)) {
1927: fprintf(stderr,
1928: "Add extension field fails\n%s\n",
1929: ERR_error_string(ERR_get_error(), NULL));
1930: return (0);
1931: }
1932: X509_EXTENSION_free(ex);
1933: }
1934:
1935: /*
1936: * Sign and verify.
1937: */
1938: X509_sign(cert, pkey, md);
1939: if (X509_verify(cert, pkey) <= 0) {
1940: fprintf(stderr, "Verify %s certificate fails\n%s\n", id,
1941: ERR_error_string(ERR_get_error(), NULL));
1942: X509_free(cert);
1943: return (0);
1944: }
1945:
1946: /*
1947: * Write the certificate encoded in PEM.
1948: */
1949: sprintf(pathbuf, "%scert", id);
1950: str = fheader(pathbuf, "cert", hostname);
1951: PEM_write_X509(str, cert);
1952: fclose(str);
1953: if (debug)
1954: X509_print_fp(stderr, cert);
1955: X509_free(cert);
1956: return (1);
1957: }
1958:
1959: #if 0 /* asn2ntp is used only with commercial certificates */
1960: /*
1961: * asn2ntp - convert ASN1_TIME time structure to NTP time
1962: */
1963: u_long
1964: asn2ntp (
1965: ASN1_TIME *asn1time /* pointer to ASN1_TIME structure */
1966: )
1967: {
1968: char *v; /* pointer to ASN1_TIME string */
1969: struct tm tm; /* time decode structure time */
1970:
1971: /*
1972: * Extract time string YYMMDDHHMMSSZ from ASN.1 time structure.
1973: * Note that the YY, MM, DD fields start with one, the HH, MM,
1974: * SS fiels start with zero and the Z character should be 'Z'
1975: * for UTC. Also note that years less than 50 map to years
1976: * greater than 100. Dontcha love ASN.1?
1977: */
1978: if (asn1time->length > 13)
1979: return (-1);
1980: v = (char *)asn1time->data;
1981: tm.tm_year = (v[0] - '0') * 10 + v[1] - '0';
1982: if (tm.tm_year < 50)
1983: tm.tm_year += 100;
1984: tm.tm_mon = (v[2] - '0') * 10 + v[3] - '0' - 1;
1985: tm.tm_mday = (v[4] - '0') * 10 + v[5] - '0';
1986: tm.tm_hour = (v[6] - '0') * 10 + v[7] - '0';
1987: tm.tm_min = (v[8] - '0') * 10 + v[9] - '0';
1988: tm.tm_sec = (v[10] - '0') * 10 + v[11] - '0';
1989: tm.tm_wday = 0;
1990: tm.tm_yday = 0;
1991: tm.tm_isdst = 0;
1992: return (mktime(&tm) + JAN_1970);
1993: }
1994: #endif
1995:
1996: /*
1997: * Callback routine
1998: */
1999: void
2000: cb (
2001: int n1, /* arg 1 */
2002: int n2, /* arg 2 */
2003: void *chr /* arg 3 */
2004: )
2005: {
2006: switch (n1) {
2007: case 0:
2008: d0++;
2009: fprintf(stderr, "%s %d %d %lu\r", (char *)chr, n1, n2,
2010: d0);
2011: break;
2012: case 1:
2013: d1++;
2014: fprintf(stderr, "%s\t\t%d %d %lu\r", (char *)chr, n1,
2015: n2, d1);
2016: break;
2017: case 2:
2018: d2++;
2019: fprintf(stderr, "%s\t\t\t\t%d %d %lu\r", (char *)chr,
2020: n1, n2, d2);
2021: break;
2022: case 3:
2023: d3++;
2024: fprintf(stderr, "%s\t\t\t\t\t\t%d %d %lu\r",
2025: (char *)chr, n1, n2, d3);
2026: break;
2027: }
2028: }
2029:
2030:
2031: /*
2032: * Generate key
2033: */
2034: EVP_PKEY * /* public/private key pair */
2035: genkey(
2036: char *type, /* key type (RSA or DSA) */
2037: char *id /* file name id */
2038: )
2039: {
2040: if (type == NULL)
2041: return (NULL);
2042: if (strcmp(type, "RSA") == 0)
2043: return (gen_rsa(id));
2044:
2045: else if (strcmp(type, "DSA") == 0)
2046: return (gen_dsa(id));
2047:
2048: fprintf(stderr, "Invalid %s key type %s\n", id, type);
2049: return (NULL);
2050: }
2051: #endif /* OPENSSL */
2052:
2053:
2054: /*
2055: * Generate file header and link
2056: */
2057: FILE *
2058: fheader (
2059: const char *file, /* file name id */
2060: const char *ulink, /* linkname */
2061: const char *owner /* owner name */
2062: )
2063: {
2064: FILE *str; /* file handle */
2065: char linkname[MAXFILENAME]; /* link name */
2066: int temp;
2067:
2068: sprintf(filename, "ntpkey_%s_%s.%lu", file, owner, epoch +
2069: JAN_1970);
2070: if ((str = fopen(filename, "w")) == NULL) {
2071: perror("Write");
2072: exit (-1);
2073: }
2074: sprintf(linkname, "ntpkey_%s_%s", ulink, owner);
2075: remove(linkname);
2076: temp = symlink(filename, linkname);
2077: if (temp < 0)
2078: perror(file);
2079: fprintf(stderr, "Generating new %s file and link\n", ulink);
2080: fprintf(stderr, "%s->%s\n", linkname, filename);
2081: fprintf(str, "# %s\n# %s\n", filename, ctime(&epoch));
2082: return (str);
2083: }
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