Return to auth-rh-rsa.c CVS log

Up to [local] / src / usr.bin / ssh

Annotation of src/usr.bin/ssh/auth-rh-rsa.c, Revision 1.4

1.1       provos      1: /*
                      2:
                      3: auth-rh-rsa.c
                      4:
                      5: Author: Tatu Ylonen <ylo@cs.hut.fi>
                      6:
                      7: Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
                      8:                    All rights reserved
                      9:
                     10: Created: Sun May  7 03:08:06 1995 ylo
                     11:
                     12: Rhosts or /etc/hosts.equiv authentication combined with RSA host
                     13: authentication.
                     14:
                     15: */
                     16:
                     17: #include "includes.h"
1.4     ! markus     18: RCSID("$Id: auth-rh-rsa.c,v 1.3 1999/11/09 23:09:58 markus Exp $");
1.1       provos     19:
                     20: #include "packet.h"
                     21: #include "ssh.h"
                     22: #include "xmalloc.h"
                     23: #include "uidswap.h"
1.4     ! markus     24: #include "servconf.h"
1.1       provos     25:
                     26: /* Tries to authenticate the user using the .rhosts file and the host using
1.4     ! markus     27:    its host key.  Returns true if authentication succeeds. */
1.1       provos     28:
                     29: int auth_rhosts_rsa(struct passwd *pw, const char *client_user,
                     30:                    unsigned int client_host_key_bits,
1.4     ! markus     31:                    BIGNUM *client_host_key_e, BIGNUM *client_host_key_n)
1.1       provos     32: {
1.4     ! markus     33:   extern ServerOptions options;
1.1       provos     34:   const char *canonical_hostname;
1.2       provos     35:   HostStatus host_status;
                     36:   BIGNUM *ke, *kn;
1.1       provos     37:
                     38:   debug("Trying rhosts with RSA host authentication for %.100s", client_user);
                     39:
                     40:   /* Check if we would accept it using rhosts authentication. */
1.4     ! markus     41:   if (!auth_rhosts(pw, client_user, options.ignore_rhosts, options.strict_modes))
1.1       provos     42:     return 0;
                     43:
                     44:   canonical_hostname = get_canonical_hostname();
                     45:
                     46:   debug("Rhosts RSA authentication: canonical host %.900s",
                     47:        canonical_hostname);
                     48:
                     49:   /* Check if we know the host and its host key. */
                     50:   /* Check system-wide host file. */
1.2       provos     51:   ke = BN_new();
                     52:   kn = BN_new();
                     53:   host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
                     54:                                       client_host_key_bits, client_host_key_e,
                     55:                                       client_host_key_n, ke, kn);
1.4     ! markus     56:
        !            57:   /* Check user host file unless ignored. */
        !            58:   if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
1.3       markus     59:     struct stat st;
                     60:     char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
                     61:     /* Check file permissions of SSH_USER_HOSTFILE,
                     62:        auth_rsa() did already check pw->pw_dir, but there is a race XXX */
1.4     ! markus     63:     if (options.strict_modes &&
1.3       markus     64:        (stat(user_hostfile, &st) == 0) &&
                     65:        ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
                     66:        (st.st_mode & 022) != 0)) {
                     67:        log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
                     68:           pw->pw_name, user_hostfile);
                     69:     } else {
                     70:       /* XXX race between stat and the following open() */
                     71:       temporarily_use_uid(pw->pw_uid);
                     72:       host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
                     73:                                           client_host_key_bits, client_host_key_e,
                     74:                                           client_host_key_n, ke, kn);
                     75:       restore_uid();
                     76:     }
                     77:     xfree(user_hostfile);
                     78:   }
1.2       provos     79:   BN_free(ke);
                     80:   BN_free(kn);
1.3       markus     81:
1.2       provos     82:   if (host_status != HOST_OK) {
                     83:     /* The host key was not found. */
                     84:     debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
                     85:     packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
                     86:     return 0;
                     87:   }
                     88:
1.1       provos     89:   /* A matching host key was found and is known. */
                     90:
                     91:   /* Perform the challenge-response dialog with the client for the host key. */
                     92:   if (!auth_rsa_challenge_dialog(client_host_key_bits,
                     93:                                 client_host_key_e, client_host_key_n))
                     94:     {
                     95:       log("Client on %.800s failed to respond correctly to host authentication.",
                     96:          canonical_hostname);
                     97:       return 0;
                     98:     }
                     99:
                    100:   /* We have authenticated the user using .rhosts or /etc/hosts.equiv, and
                    101:      the host using RSA.  We accept the authentication. */
                    102:
                    103:   log("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
                    104:       pw->pw_name, client_user, canonical_hostname);
                    105:   packet_send_debug("Rhosts with RSA host authentication accepted.");
                    106:   return 1;
                    107: }