ssh-add.c

/*

ssh-add.c

Author: Tatu Ylonen <ylo@cs.hut.fi>

Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
                   All rights reserved

Created: Thu Apr  6 00:52:24 1995 ylo

Adds an identity to the authentication server, or removes an identity.

*/

#include "includes.h"
RCSID("$Id: ssh-add.c,v 1.3 1999/11/08 04:30:59 damien Exp $");

#include "rsa.h"
#include "ssh.h"
#include "xmalloc.h"
#include "authfd.h"

void
delete_file(AuthenticationConnection *ac, const char *filename)
{
  RSA *key;
  char *comment;

  key = RSA_new();
  if (!load_public_key(filename, key, &comment))
    {
      printf("Bad key file %s: %s\n", filename, strerror(errno));
      return;
    }

  if (ssh_remove_identity(ac, key))
    fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
  else
    fprintf(stderr, "Could not remove identity: %s\n", filename);
  RSA_free(key);
  xfree(comment);
}

void
delete_all(AuthenticationConnection *ac)
{
  /* Send a request to remove all identities. */
  if (ssh_remove_all_identities(ac))
    fprintf(stderr, "All identities removed.\n");
  else
    fprintf(stderr, "Failed to remove all identitities.\n");
}

#define BUFSIZE 1024
void
add_file(AuthenticationConnection *ac, const char *filename)
{
  RSA *key;
  RSA *public_key;
  char *saved_comment, *comment, *pass;
  int first;
  int pipes[2];
  char buf[BUFSIZE];
  int tmp;
  pid_t child;
  FILE *pipef;
  
  key = RSA_new();
  public_key = RSA_new();
  if (!load_public_key(filename, public_key, &saved_comment))
    {
      printf("Bad key file %s: %s\n", filename, strerror(errno));
      return;
    }
  RSA_free(public_key);
  
  pass = xstrdup("");
  first = 1;
  while (!load_private_key(filename, pass, key, &comment))
    {
      /* Free the old passphrase. */
      memset(pass, 0, strlen(pass));
      xfree(pass);

      /* Ask for a passphrase. */
      if (getenv("DISPLAY") && !isatty(fileno(stdin)))
	{
          if (pipe(pipes) ==-1)
            {
              fprintf(stderr, "Creating pipes failed: %s\n", strerror(errno));
              exit(1);
            }
          if (fflush(NULL)==EOF)
            {
              fprintf(stderr, "Cannot flush buffers: %s\n", strerror(errno));
              exit(1);
            }
          switch (child=fork())
            {
            case -1:
              fprintf(stderr, "Cannot fork: %s\n", strerror(errno));
              exit(1);
            case 0:
              close(pipes[0]);
              if (dup2(pipes[1], 1) ==-1)
                {
                  fprintf(stderr, "dup2 failed: %s\n", strerror(errno));
                  exit(1);
                }
              tmp=snprintf(buf, BUFSIZE, "Need passphrase for %s (%s)",
                           filename, saved_comment);
              /* skip the prompt if it won't fit */
              if (tmp < 0 || tmp >= BUFSIZE)
                tmp=execlp("/usr/lib/ssh/ssh-askpass", "ssh-askpass", 0);
              else
                tmp=execlp("/usr/lib/ssh/ssh-askpass", "ssh-askpass", buf, 0);
              if (tmp==-1)
                {
                  fprintf(stderr, "Executing ssh-askpass failed: %s\n",
                          strerror(errno));
                  exit(1);
                }
              break;
            default:
              close(pipes[1]);
              if ( (pipef=fdopen(pipes[0], "r")) ==NULL)
                {
                  fprintf(stderr, "fdopen failed: %s\n", strerror(errno));
                  exit(1);
                }
              if(fgets(buf, sizeof(buf), pipef)==NULL)
                {
                  xfree(saved_comment);
                  return;
                }
              fclose(pipef);
              if (strchr(buf, '\n'))
                *strchr(buf, '\n') = 0;
              pass = xstrdup(buf);
              memset(buf, 0, sizeof(buf));
              if (waitpid(child, NULL, 0) ==-1)
                {
                  fprintf(stderr, "Waiting for child failed: %s\n",
                          strerror(errno));
                  exit(1);
                }
              if (strcmp(pass, "") == 0)
                {
                  xfree(saved_comment);
                  xfree(pass);
                  return;
                }
            }
	}
      else
	{
	  if (first)
	    printf("Need passphrase for %s (%s).\n", filename, saved_comment);
	  else
	    printf("Bad passphrase.\n");
	  pass = read_passphrase("Enter passphrase: ", 1);
	  if (strcmp(pass, "") == 0)
	    {
	      xfree(saved_comment);
	      xfree(pass);
	      return;
	    }
	}
      first = 0;
    }
  memset(pass, 0, strlen(pass));
  xfree(pass);

  xfree(saved_comment);

  if (ssh_add_identity(ac, key, comment))
    fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
  else
    fprintf(stderr, "Could not add identity: %s\n", filename);
  RSA_free(key);
  xfree(comment);
}

void
list_identities(AuthenticationConnection *ac)
{
  BIGNUM *e, *n;
  int bits, status;
  char *comment;
  int had_identities;

  e = BN_new();
  n = BN_new();
  had_identities = 0;
  for (status = ssh_get_first_identity(ac, &bits, e, n, &comment);
       status;
       status = ssh_get_next_identity(ac, &bits, e, n, &comment))
    {
      char *buf;
      had_identities = 1;
      printf("%d ", bits);
      buf = BN_bn2dec(e);
      assert(buf != NULL);
      printf("%s ", buf);
      free (buf);
      buf = BN_bn2dec(n);
      assert(buf != NULL);
      printf("%s %s\n", buf, comment);
      free (buf);
      xfree(comment);
    }
  BN_clear_free(e);
  BN_clear_free(n);
  if (!had_identities)
    printf("The agent has no identities.\n");
}

int
main(int argc, char **argv)
{
  AuthenticationConnection *ac = NULL;
  struct passwd *pw;
  char buf[1024];
  int no_files = 1;
  int i;
  int deleting = 0;

  /* check if RSA support exists */
  if (rsa_alive() == 0) {
    extern char *__progname;

    fprintf(stderr,
      "%s: no RSA support in libssl and libcrypto.  See ssl(8).\n",
      __progname);
    exit(1);
  }

  /* At first, get a connection to the authentication agent. */
  ac = ssh_get_authentication_connection();
  if (ac == NULL) {
    fprintf(stderr, "Could not open a connection to your authentication agent.\n");
    exit(1);
  }

  for (i = 1; i < argc; i++)
    {
      if (strcmp(argv[i], "-l") == 0)
	{
	  list_identities(ac);
	  no_files = 0; /* Don't default-add/delete if -l. */
	  continue;
	}
      if (strcmp(argv[i], "-d") == 0)
	{
	  deleting = 1;
	  continue;
	}
      if (strcmp(argv[i], "-D") == 0)
	{
	  delete_all(ac);
	  no_files = 0;
	  continue;
	}
      no_files = 0;
      if (deleting)
	delete_file(ac, argv[i]);
      else
	add_file(ac, argv[i]);
    }
  if (no_files)
    {
      pw = getpwuid(getuid());
      if (!pw)
	{
	  fprintf(stderr, "No user found with uid %d\n", (int)getuid());
	  ssh_close_authentication_connection(ac);
	  exit(1);
	}
      snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, SSH_CLIENT_IDENTITY);
      if (deleting)
	delete_file(ac, buf);
      else
	add_file(ac, buf);
    }
  ssh_close_authentication_connection(ac);
  exit(0);
}