- markus@cvs.openbsd.org 2003/07/23 07:42:43
[sshd_config]
remove AFS; itojun@
+ - djm@cvs.openbsd.org 2003/07/28 09:49:56
+ [ssh-keygen.1 ssh-keygen.c]
+ Support for generating Diffie-Hellman groups (/etc/moduli) from ssh-keygen.
+ Based on code from Phil Karn, William Allen Simpson and Niels Provos.
+ ok markus@, thanks jmc@
20030730
- (djm) [auth-pam.c] Don't use crappy APIs like sprintf. Thanks bal
- Fix sshd BindAddress and -b options for systems using fake-getaddrinfo.
Report from murple@murple.net, diagnosis from dtucker@zip.com.au
-$Id: ChangeLog,v 1.2870 2003/08/02 12:31:45 dtucker Exp $
+$Id: ChangeLog,v 1.2871 2003/08/02 12:40:07 dtucker Exp $
-.\" $OpenBSD: ssh-keygen.1,v 1.59 2003/06/10 09:12:11 jmc Exp $
+.\" $OpenBSD: ssh-keygen.1,v 1.60 2003/07/28 09:49:56 djm Exp $
.\"
.\" -*- nroff -*-
.\"
.Fl r Ar hostname
.Op Fl f Ar input_keyfile
.Op Fl g
+.Nm ssh-keygen
+.Fl G Ar output_file
+.Op Fl b Ar bits
+.Op Fl M Ar memory
+.Op Fl S Ar start_point
+.Nm ssh-keygen
+.Fl T Ar output_file
+.Fl f Ar input_file
+.Op Fl a Ar num_trials
+.Op Fl W Ar generator
.Sh DESCRIPTION
.Nm
generates, manages and converts authentication keys for
.Fl t
option.
.Pp
+.Nm
+is also used to generate groups for use in Diffie-Hellman group
+exchange (DH-GEX).
+See the
+.Sx MODULI GENERATION
+section for details.
+.Pp
Normally each user wishing to use SSH
with RSA or DSA authentication runs this once to create the authentication
key in
.Pp
The options are as follows:
.Bl -tag -width Ds
+.It Fl a Ar trials
+Specifies the number of primality tests to perform when screening DH-GEX
+candidates using the
+.Fl T
+command.
.It Fl b Ar bits
Specifies the number of bits in the key to create.
Minimum is 512 bits.
.It Fl D Ar reader
Download the RSA public key stored in the smartcard in
.Ar reader .
+.It Fl G Ar output_file
+Generate candidate primes for DH-GEX.
+These primes must be screened for
+safety (using the
+.Fl T
+option) before use.
+.It Fl M Ar memory
+Specify the amount of memory to use (in megabytes) when generating
+candidate moduli for DH-GEX.
.It Fl N Ar new_passphrase
Provides the new passphrase.
.It Fl P Ar passphrase
Provides the (old) passphrase.
+.It Fl S Ar start
+Specify start point (in hex) when generating candidate moduli for DH-GEX.
+.It Fl T Ar output_file
+Test DH group exchange candidate primes (generated using the
+.Fl G
+option) for safety.
+.It Fl W Ar generator
+Specify desired generator when testing candidate moduli for DH-GEX.
.It Fl U Ar reader
Upload an existing RSA private key into the smartcard in
.Ar reader .
Print DNS resource record with the specified
.Ar hostname .
.El
+.Sh MODULI GENERATION
+.Nm
+may be used to generate groups for the Diffie-Hellman Group Exchange
+(DH-GEX) protocol.
+Generating these groups is a two-step process: first, candidate
+primes are generated using a fast, but memory intensive process.
+These candidate primes are then tested for suitability (a CPU-intensive
+process).
+.Pp
+Generation of primes is performed using the
+.Fl G
+option.
+The desired length of the primes may be specified by the
+.Fl b
+option.
+For example:
+.Pp
+.Dl ssh-keygen -G moduli-2048.candidates -b 2048
+.Pp
+By default, the search for primes begins at a random point in the
+desired length range.
+This may be overridden using the
+.Fl S
+option, which specifies a different start point (in hex).
+.Pp
+Once a set of candidates have been generated, they must be tested for
+suitability.
+This may be performed using the
+.Fl T
+option.
+In this mode
+.Nm
+will read candidates from standard input (or a file specified using the
+.Fl f
+option).
+For example:
+.Pp
+.Dl ssh-keygen -T moduli-2048 -f moduli-2048.candidates
+.Pp
+By default, each candidate will be subjected to 100 primality tests.
+This may be overridden using the
+.Fl a
+option.
+The DH generator value will be chosen automatically for the
+prime under consideration.
+If a specific generator is desired, it may be requested using the
+.Fl W
+option.
+Valid generator values are 2, 3 and 5.
+.Pp
+Screened DH groups may be installed in
+.Pa /etc/moduli .
+It is important that this file contains moduli of a range of bit lengths and
+that both ends of a connection share common moduli.
.Sh FILES
.Bl -tag -width Ds
.It Pa $HOME/.ssh/identity
on all machines
where the user wishes to log in using public key authentication.
There is no need to keep the contents of this file secret.
+.It Pa /etc/moduli
+Contains Diffie-Hellman groups used for DH-GEX.
+The file format is described in
+.Xr moduli 5 .
.El
.Sh SEE ALSO
.Xr ssh 1 ,
.Xr ssh-add 1 ,
.Xr ssh-agent 1 ,
+.Xr moduli 5 ,
.Xr sshd 8
.Rs
.%A J. Galbraith
*/
#include "includes.h"
-RCSID("$OpenBSD: ssh-keygen.c,v 1.106 2003/05/15 03:10:52 djm Exp $");
+RCSID("$OpenBSD: ssh-keygen.c,v 1.107 2003/07/28 09:49:56 djm Exp $");
#include <openssl/evp.h>
#include <openssl/pem.h>
#include "pathnames.h"
#include "log.h"
#include "readpass.h"
+#include "moduli.h"
#ifdef SMARTCARD
#include "scard.h"
fprintf(stderr, " -U reader Upload private key to smartcard.\n");
#endif /* SMARTCARD */
+ fprintf(stderr, " -G file Generate candidates for DH-GEX moduli\n");
+ fprintf(stderr, " -T file Screen candidates for DH-GEX moduli\n");
+
exit(1);
}
main(int ac, char **av)
{
char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
- char *reader_id = NULL;
+ char out_file[PATH_MAX], *reader_id = NULL;
char *resource_record_hostname = NULL;
Key *private, *public;
struct passwd *pw;
struct stat st;
- int opt, type, fd, download = 0;
+ int opt, type, fd, download = 0, memory = 0;
+ int generator_wanted = 0, trials = 100;
+ int do_gen_candidates = 0, do_screen_candidates = 0;
+ BIGNUM *start = NULL;
FILE *f;
extern int optind;
__progname = get_progname(av[0]);
SSLeay_add_all_algorithms();
+ log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
+
init_rng();
seed_rng();
exit(1);
}
- while ((opt = getopt(ac, av, "degiqpclBRxXyb:f:t:U:D:P:N:C:r:")) != -1) {
+ while ((opt = getopt(ac, av,
+ "degiqpclBRxXyb:f:t:U:D:P:N:C:r:g:T:G:M:S:a:W:")) != -1) {
switch (opt) {
case 'b':
bits = atoi(optarg);
case 'r':
resource_record_hostname = optarg;
break;
+ case 'W':
+ generator_wanted = atoi(optarg);
+ if (generator_wanted < 1)
+ fatal("Desired generator has bad value.");
+ break;
+ case 'a':
+ trials = atoi(optarg);
+ if (trials < TRIAL_MINIMUM) {
+ fatal("Minimum primality trials is %d",
+ TRIAL_MINIMUM);
+ }
+ break;
+ case 'M':
+ memory = atoi(optarg);
+ if (memory != 0 &&
+ (memory < LARGE_MINIMUM || memory > LARGE_MAXIMUM)) {
+ fatal("Invalid memory amount (min %ld, max %ld)",
+ LARGE_MINIMUM, LARGE_MAXIMUM);
+ }
+ break;
+ case 'G':
+ do_gen_candidates = 1;
+ strlcpy(out_file, optarg, sizeof(out_file));
+ break;
+ case 'T':
+ do_screen_candidates = 1;
+ strlcpy(out_file, optarg, sizeof(out_file));
+ break;
+ case 'S':
+ /* XXX - also compare length against bits */
+ if (BN_hex2bn(&start, optarg) == 0)
+ fatal("Invalid start point.");
+ break;
case '?':
default:
usage();
#endif /* SMARTCARD */
}
+ if (do_gen_candidates) {
+ FILE *out = fopen(out_file, "w");
+
+ if (out == NULL) {
+ error("Couldn't open modulus candidate file \"%s\": %s",
+ out_file, strerror(errno));
+ return (1);
+ }
+ if (gen_candidates(out, memory, bits, start) != 0)
+ fatal("modulus candidate generation failed\n");
+
+ return (0);
+ }
+
+ if (do_screen_candidates) {
+ FILE *in;
+ FILE *out = fopen(out_file, "w");
+
+ if (have_identity && strcmp(identity_file, "-") != 0) {
+ if ((in = fopen(identity_file, "r")) == NULL) {
+ fatal("Couldn't open modulus candidate "
+ "file \"%s\": %s", identity_file,
+ strerror(errno));
+ }
+ } else
+ in = stdin;
+
+ if (out == NULL) {
+ fatal("Couldn't open moduli file \"%s\": %s",
+ out_file, strerror(errno));
+ }
+ if (prime_test(in, out, trials, generator_wanted) != 0)
+ fatal("modulus screening failed\n");
+ }
+
arc4random_stir();
if (key_type_name == NULL) {
projects / thirdparty / openssh-portable.git / commitdiff
