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Commit | Line | Data |
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8efc0c15 | 1 | /* |
5260325f | 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 | */ | |
8efc0c15 | 16 | |
17 | #include "includes.h" | |
18 | RCSID("$Id$"); | |
19 | ||
20 | #include "packet.h" | |
21 | #include "ssh.h" | |
22 | #include "xmalloc.h" | |
23 | #include "uidswap.h" | |
b4748e2f | 24 | #include "servconf.h" |
8efc0c15 | 25 | |
aa3378df | 26 | /* |
27 | * Tries to authenticate the user using the .rhosts file and the host using | |
28 | * its host key. Returns true if authentication succeeds. | |
29 | */ | |
8efc0c15 | 30 | |
5260325f | 31 | int |
32 | auth_rhosts_rsa(struct passwd *pw, const char *client_user, | |
33 | BIGNUM *client_host_key_e, BIGNUM *client_host_key_n) | |
8efc0c15 | 34 | { |
5260325f | 35 | extern ServerOptions options; |
36 | const char *canonical_hostname; | |
37 | HostStatus host_status; | |
38 | BIGNUM *ke, *kn; | |
39 | ||
40 | debug("Trying rhosts with RSA host authentication for %.100s", client_user); | |
41 | ||
42 | /* Check if we would accept it using rhosts authentication. */ | |
43 | if (!auth_rhosts(pw, client_user)) | |
44 | return 0; | |
45 | ||
46 | canonical_hostname = get_canonical_hostname(); | |
47 | ||
48 | debug("Rhosts RSA authentication: canonical host %.900s", | |
49 | canonical_hostname); | |
50 | ||
51 | /* Check if we know the host and its host key. */ | |
52 | ke = BN_new(); | |
53 | kn = BN_new(); | |
54 | host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname, | |
55 | client_host_key_e, client_host_key_n, | |
56 | ke, kn); | |
57 | ||
58 | /* Check user host file unless ignored. */ | |
59 | if (host_status != HOST_OK && !options.ignore_user_known_hosts) { | |
60 | struct stat st; | |
61 | char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid); | |
aa3378df | 62 | /* |
63 | * Check file permissions of SSH_USER_HOSTFILE, auth_rsa() | |
64 | * did already check pw->pw_dir, but there is a race XXX | |
65 | */ | |
5260325f | 66 | if (options.strict_modes && |
67 | (stat(user_hostfile, &st) == 0) && | |
68 | ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || | |
69 | (st.st_mode & 022) != 0)) { | |
70 | log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s", | |
71 | pw->pw_name, user_hostfile); | |
72 | } else { | |
73 | /* XXX race between stat and the following open() */ | |
74 | temporarily_use_uid(pw->pw_uid); | |
75 | host_status = check_host_in_hostfile(user_hostfile, canonical_hostname, | |
76 | client_host_key_e, client_host_key_n, | |
77 | ke, kn); | |
78 | restore_uid(); | |
79 | } | |
80 | xfree(user_hostfile); | |
81 | } | |
82 | BN_free(ke); | |
83 | BN_free(kn); | |
84 | ||
85 | if (host_status != HOST_OK) { | |
86 | debug("Rhosts with RSA host authentication denied: unknown or invalid host key"); | |
87 | packet_send_debug("Your host key cannot be verified: unknown or invalid host key."); | |
88 | return 0; | |
89 | } | |
90 | /* A matching host key was found and is known. */ | |
91 | ||
92 | /* Perform the challenge-response dialog with the client for the host key. */ | |
93 | if (!auth_rsa_challenge_dialog(client_host_key_e, client_host_key_n)) { | |
94 | log("Client on %.800s failed to respond correctly to host authentication.", | |
95 | canonical_hostname); | |
96 | return 0; | |
97 | } | |
aa3378df | 98 | /* |
99 | * We have authenticated the user using .rhosts or /etc/hosts.equiv, | |
100 | * and the host using RSA. We accept the authentication. | |
101 | */ | |
5260325f | 102 | |
103 | verbose("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; | |
8efc0c15 | 107 | } |