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openssh/ssh-keygen.c
Damien Miller 5428f646ad - More reformatting merged from OpenBSD CVS
- Merged OpenBSD CVS changes:
   - [channels.c]
     report from mrwizard@psu.edu via djm@ibs.com.au
   - [channels.c]
     set SO_REUSEADDR and SO_LINGER for forwarded ports.
     chip@valinux.com via damien@ibs.com.au
   - [nchan.c]
     it's not an error() if shutdown_write failes in nchan.
   - [readconf.c]
     remove dead #ifdef-0-code
   - [readconf.c servconf.c]
     strcasecmp instead of tolower
   - [scp.c]
     progress meter overflow fix from damien@ibs.com.au
   - [ssh-add.1 ssh-add.c]
     SSH_ASKPASS support
   - [ssh.1 ssh.c]
     postpone fork_after_authentication until command execution,
     request/patch from jahakala@cc.jyu.fi via damien@ibs.com.au
     plus: use daemon() for backgrounding
1999-11-25 11:54:57 +11:00

525 lines
13 KiB
C

/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Created: Mon Mar 27 02:26:40 1995 ylo
* Identity and host key generation and maintenance.
*/
#include "includes.h"
RCSID("$Id: ssh-keygen.c,v 1.10 1999/11/25 00:54:59 damien Exp $");
#include "rsa.h"
#include "ssh.h"
#include "xmalloc.h"
#include "fingerprint.h"
/* Generated private key. */
RSA *private_key;
/* Generated public key. */
RSA *public_key;
/* Number of bits in the RSA key. This value can be changed on the command line. */
int bits = 1024;
/*
* Flag indicating that we just want to change the passphrase. This can be
* set on the command line.
*/
int change_passphrase = 0;
/*
* Flag indicating that we just want to change the comment. This can be set
* on the command line.
*/
int change_comment = 0;
int quiet = 0;
/* Flag indicating that we just want to see the key fingerprint */
int print_fingerprint = 0;
/* The identity file name, given on the command line or entered by the user. */
char identity_file[1024];
int have_identity = 0;
/* This is set to the passphrase if given on the command line. */
char *identity_passphrase = NULL;
/* This is set to the new passphrase if given on the command line. */
char *identity_new_passphrase = NULL;
/* This is set to the new comment if given on the command line. */
char *identity_comment = NULL;
/* argv0 */
#ifdef HAVE___PROGNAME
extern char *__progname;
#else /* HAVE___PROGNAME */
const char *__progname = "ssh-keygen";
#endif /* HAVE___PROGNAME */
void
ask_filename(struct passwd *pw, const char *prompt)
{
char buf[1024];
snprintf(identity_file, sizeof(identity_file), "%s/%s",
pw->pw_dir, SSH_CLIENT_IDENTITY);
printf("%s (%s): ", prompt, identity_file);
fflush(stdout);
if (fgets(buf, sizeof(buf), stdin) == NULL)
exit(1);
if (strchr(buf, '\n'))
*strchr(buf, '\n') = 0;
if (strcmp(buf, "") != 0)
strlcpy(identity_file, buf, sizeof(identity_file));
have_identity = 1;
}
void
do_fingerprint(struct passwd *pw)
{
char *comment;
RSA *public_key;
struct stat st;
if (!have_identity)
ask_filename(pw, "Enter file in which the key is");
if (stat(identity_file, &st) < 0) {
perror(identity_file);
exit(1);
}
public_key = RSA_new();
if (!load_public_key(identity_file, public_key, &comment)) {
char *cp, line[1024];
BIGNUM *e, *n;
int dummy, invalid = 0;
FILE *f = fopen(identity_file, "r");
n = BN_new();
e = BN_new();
if (f && fgets(line, sizeof(line), f)) {
cp = line;
line[strlen(line) - 1] = '\0';
if (auth_rsa_read_key(&cp, &dummy, e, n)) {
public_key->e = e;
public_key->n = n;
comment = xstrdup(cp ? cp : "no comment");
} else {
invalid = 1;
}
} else {
invalid = 1;
}
if (invalid) {
printf("%s is not a valid key file.\n", identity_file);
BN_free(e);
BN_free(n);
exit(1);
}
}
printf("%d %s %s\n", BN_num_bits(public_key->n),
fingerprint(public_key->e, public_key->n),
comment);
RSA_free(public_key);
exit(0);
}
/*
* Perform changing a passphrase. The argument is the passwd structure
* for the current user.
*/
void
do_change_passphrase(struct passwd *pw)
{
char *comment;
char *old_passphrase, *passphrase1, *passphrase2;
struct stat st;
RSA *private_key;
if (!have_identity)
ask_filename(pw, "Enter file in which the key is");
if (stat(identity_file, &st) < 0) {
perror(identity_file);
exit(1);
}
public_key = RSA_new();
if (!load_public_key(identity_file, public_key, NULL)) {
printf("%s is not a valid key file.\n", identity_file);
exit(1);
}
/* Clear the public key since we are just about to load the whole file. */
RSA_free(public_key);
/* Try to load the file with empty passphrase. */
private_key = RSA_new();
if (!load_private_key(identity_file, "", private_key, &comment)) {
if (identity_passphrase)
old_passphrase = xstrdup(identity_passphrase);
else
old_passphrase = read_passphrase("Enter old passphrase: ", 1);
if (!load_private_key(identity_file, old_passphrase, private_key, &comment)) {
memset(old_passphrase, 0, strlen(old_passphrase));
xfree(old_passphrase);
printf("Bad passphrase.\n");
exit(1);
}
memset(old_passphrase, 0, strlen(old_passphrase));
xfree(old_passphrase);
}
printf("Key has comment '%s'\n", comment);
/* Ask the new passphrase (twice). */
if (identity_new_passphrase) {
passphrase1 = xstrdup(identity_new_passphrase);
passphrase2 = NULL;
} else {
passphrase1 =
read_passphrase("Enter new passphrase (empty for no passphrase): ", 1);
passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
/* Verify that they are the same. */
if (strcmp(passphrase1, passphrase2) != 0) {
memset(passphrase1, 0, strlen(passphrase1));
memset(passphrase2, 0, strlen(passphrase2));
xfree(passphrase1);
xfree(passphrase2);
printf("Pass phrases do not match. Try again.\n");
exit(1);
}
/* Destroy the other copy. */
memset(passphrase2, 0, strlen(passphrase2));
xfree(passphrase2);
}
/* Save the file using the new passphrase. */
if (!save_private_key(identity_file, passphrase1, private_key, comment)) {
printf("Saving the key failed: %s: %s.\n",
identity_file, strerror(errno));
memset(passphrase1, 0, strlen(passphrase1));
xfree(passphrase1);
RSA_free(private_key);
xfree(comment);
exit(1);
}
/* Destroy the passphrase and the copy of the key in memory. */
memset(passphrase1, 0, strlen(passphrase1));
xfree(passphrase1);
RSA_free(private_key); /* Destroys contents */
xfree(comment);
printf("Your identification has been saved with the new passphrase.\n");
exit(0);
}
/*
* Change the comment of a private key file.
*/
void
do_change_comment(struct passwd *pw)
{
char new_comment[1024], *comment;
RSA *private_key;
char *passphrase;
struct stat st;
FILE *f;
char *tmpbuf;
if (!have_identity)
ask_filename(pw, "Enter file in which the key is");
if (stat(identity_file, &st) < 0) {
perror(identity_file);
exit(1);
}
/*
* Try to load the public key from the file the verify that it is
* readable and of the proper format.
*/
public_key = RSA_new();
if (!load_public_key(identity_file, public_key, NULL)) {
printf("%s is not a valid key file.\n", identity_file);
exit(1);
}
private_key = RSA_new();
if (load_private_key(identity_file, "", private_key, &comment))
passphrase = xstrdup("");
else {
if (identity_passphrase)
passphrase = xstrdup(identity_passphrase);
else if (identity_new_passphrase)
passphrase = xstrdup(identity_new_passphrase);
else
passphrase = read_passphrase("Enter passphrase: ", 1);
/* Try to load using the passphrase. */
if (!load_private_key(identity_file, passphrase, private_key, &comment)) {
memset(passphrase, 0, strlen(passphrase));
xfree(passphrase);
printf("Bad passphrase.\n");
exit(1);
}
}
printf("Key now has comment '%s'\n", comment);
if (identity_comment) {
strlcpy(new_comment, identity_comment, sizeof(new_comment));
} else {
printf("Enter new comment: ");
fflush(stdout);
if (!fgets(new_comment, sizeof(new_comment), stdin)) {
memset(passphrase, 0, strlen(passphrase));
RSA_free(private_key);
exit(1);
}
if (strchr(new_comment, '\n'))
*strchr(new_comment, '\n') = 0;
}
/* Save the file using the new passphrase. */
if (!save_private_key(identity_file, passphrase, private_key, new_comment)) {
printf("Saving the key failed: %s: %s.\n",
identity_file, strerror(errno));
memset(passphrase, 0, strlen(passphrase));
xfree(passphrase);
RSA_free(private_key);
xfree(comment);
exit(1);
}
memset(passphrase, 0, strlen(passphrase));
xfree(passphrase);
RSA_free(private_key);
strlcat(identity_file, ".pub", sizeof(identity_file));
f = fopen(identity_file, "w");
if (!f) {
printf("Could not save your public key in %s\n", identity_file);
exit(1);
}
fprintf(f, "%d ", BN_num_bits(public_key->n));
tmpbuf = BN_bn2dec(public_key->e);
fprintf(f, "%s ", tmpbuf);
free(tmpbuf);
tmpbuf = BN_bn2dec(public_key->n);
fprintf(f, "%s %s\n", tmpbuf, new_comment);
free(tmpbuf);
fclose(f);
xfree(comment);
printf("The comment in your key file has been changed.\n");
exit(0);
}
void
usage(void)
{
printf("ssh-keygen version %s\n", SSH_VERSION);
printf("Usage: %s [-b bits] [-p] [-c] [-f file] [-P pass] [-N new-pass] [-C comment]\n", __progname);
exit(1);
}
/*
* Main program for key management.
*/
int
main(int ac, char **av)
{
char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
struct passwd *pw;
char *tmpbuf;
int opt;
struct stat st;
FILE *f;
char hostname[MAXHOSTNAMELEN];
extern int optind;
extern char *optarg;
/* check if RSA support exists */
if (rsa_alive() == 0) {
fprintf(stderr,
"%s: no RSA support in libssl and libcrypto. See ssl(8).\n",
__progname);
exit(1);
}
/* we need this for the home * directory. */
pw = getpwuid(getuid());
if (!pw) {
printf("You don't exist, go away!\n");
exit(1);
}
while ((opt = getopt(ac, av, "qpclb:f:P:N:C:")) != EOF) {
switch (opt) {
case 'b':
bits = atoi(optarg);
if (bits < 512 || bits > 32768) {
printf("Bits has bad value.\n");
exit(1);
}
break;
case 'l':
print_fingerprint = 1;
break;
case 'p':
change_passphrase = 1;
break;
case 'c':
change_comment = 1;
break;
case 'f':
strlcpy(identity_file, optarg, sizeof(identity_file));
have_identity = 1;
break;
case 'P':
identity_passphrase = optarg;
break;
case 'N':
identity_new_passphrase = optarg;
break;
case 'C':
identity_comment = optarg;
break;
case 'q':
quiet = 1;
break;
case '?':
default:
usage();
}
}
if (optind < ac) {
printf("Too many arguments.\n");
usage();
}
if (change_passphrase && change_comment) {
printf("Can only have one of -p and -c.\n");
usage();
}
if (print_fingerprint)
do_fingerprint(pw);
if (change_passphrase)
do_change_passphrase(pw);
if (change_comment)
do_change_comment(pw);
arc4random_stir();
if (quiet)
rsa_set_verbose(0);
/* Generate the rsa key pair. */
private_key = RSA_new();
public_key = RSA_new();
rsa_generate_key(private_key, public_key, bits);
if (!have_identity)
ask_filename(pw, "Enter file in which to save the key");
/* Create ~/.ssh directory if it doesn\'t already exist. */
snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, SSH_USER_DIR);
if (strstr(identity_file, dotsshdir) != NULL &&
stat(dotsshdir, &st) < 0) {
if (mkdir(dotsshdir, 0755) < 0)
error("Could not create directory '%s'.", dotsshdir);
else if (!quiet)
printf("Created directory '%s'.\n", dotsshdir);
}
/* If the file already exists, ask the user to confirm. */
if (stat(identity_file, &st) >= 0) {
char yesno[3];
printf("%s already exists.\n", identity_file);
printf("Overwrite (y/n)? ");
fflush(stdout);
if (fgets(yesno, sizeof(yesno), stdin) == NULL)
exit(1);
if (yesno[0] != 'y' && yesno[0] != 'Y')
exit(1);
}
/* Ask for a passphrase (twice). */
if (identity_passphrase)
passphrase1 = xstrdup(identity_passphrase);
else if (identity_new_passphrase)
passphrase1 = xstrdup(identity_new_passphrase);
else {
passphrase_again:
passphrase1 =
read_passphrase("Enter passphrase (empty for no passphrase): ", 1);
passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
if (strcmp(passphrase1, passphrase2) != 0) {
/* The passphrases do not match. Clear them and retry. */
memset(passphrase1, 0, strlen(passphrase1));
memset(passphrase2, 0, strlen(passphrase2));
xfree(passphrase1);
xfree(passphrase2);
printf("Passphrases do not match. Try again.\n");
goto passphrase_again;
}
/* Clear the other copy of the passphrase. */
memset(passphrase2, 0, strlen(passphrase2));
xfree(passphrase2);
}
if (identity_comment) {
strlcpy(comment, identity_comment, sizeof(comment));
} else {
/* Create default commend field for the passphrase. */
if (gethostname(hostname, sizeof(hostname)) < 0) {
perror("gethostname");
exit(1);
}
snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
}
/* Save the key with the given passphrase and comment. */
if (!save_private_key(identity_file, passphrase1, private_key, comment)) {
printf("Saving the key failed: %s: %s.\n",
identity_file, strerror(errno));
memset(passphrase1, 0, strlen(passphrase1));
xfree(passphrase1);
exit(1);
}
/* Clear the passphrase. */
memset(passphrase1, 0, strlen(passphrase1));
xfree(passphrase1);
/* Clear the private key and the random number generator. */
RSA_free(private_key);
arc4random_stir();
if (!quiet)
printf("Your identification has been saved in %s.\n", identity_file);
strlcat(identity_file, ".pub", sizeof(identity_file));
f = fopen(identity_file, "w");
if (!f) {
printf("Could not save your public key in %s\n", identity_file);
exit(1);
}
fprintf(f, "%d ", BN_num_bits(public_key->n));
tmpbuf = BN_bn2dec(public_key->e);
fprintf(f, "%s ", tmpbuf);
free(tmpbuf);
tmpbuf = BN_bn2dec(public_key->n);
fprintf(f, "%s %s\n", tmpbuf, comment);
free(tmpbuf);
fclose(f);
if (!quiet) {
printf("Your public key has been saved in %s.\n", identity_file);
printf("The key fingerprint is:\n");
printf("%d %s %s\n", BN_num_bits(public_key->n),
fingerprint(public_key->e, public_key->n),
comment);
}
exit(0);
}