/*
- *
- * auth-rsa.c
- *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- *
- * Created: Mon Mar 27 01:46:52 1995 ylo
- *
* RSA-based authentication. This code determines whether to admit a login
* based on RSA authentication. This file also contains functions to check
* validity of the host key.
*
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
-RCSID("$Id$");
+RCSID("$OpenBSD: auth-rsa.c,v 1.44 2001/07/23 18:14:58 stevesk Exp $");
+
+#include <openssl/rsa.h>
+#include <openssl/md5.h>
#include "rsa.h"
#include "packet.h"
#include "xmalloc.h"
-#include "ssh.h"
+#include "ssh1.h"
#include "mpaux.h"
#include "uidswap.h"
#include "match.h"
-#include "servconf.h"
#include "auth-options.h"
+#include "pathnames.h"
+#include "log.h"
+#include "servconf.h"
+#include "auth.h"
-#include <openssl/rsa.h>
-#include <openssl/md5.h>
+/* import */
+extern ServerOptions options;
/*
* Session identifier that is used to bind key exchange and authentication
* responses to a particular session.
*/
-extern unsigned char session_id[16];
+extern u_char session_id[16];
/*
* The .ssh/authorized_keys file contains public keys, one per line, in the
{
BIGNUM *challenge, *encrypted_challenge;
BN_CTX *ctx;
- unsigned char buf[32], mdbuf[16], response[16];
+ u_char buf[32], mdbuf[16], response[16];
MD5_CTX md;
- unsigned int i;
+ u_int i;
int plen, len;
encrypted_challenge = BN_new();
int
auth_rsa(struct passwd *pw, BIGNUM *client_n)
{
- extern ServerOptions options;
- char line[8192], file[1024];
+ char line[8192], *file;
int authenticated;
- unsigned int bits;
+ u_int bits;
FILE *f;
- unsigned long linenum = 0;
+ u_long linenum = 0;
struct stat st;
RSA *pk;
+ /* no user given */
+ if (pw == NULL)
+ return 0;
+
/* Temporarily use the user's uid. */
- temporarily_use_uid(pw->pw_uid);
+ temporarily_use_uid(pw);
/* The authorized keys. */
- snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir,
- SSH_USER_PERMITTED_KEYS);
+ file = authorized_keys_file(pw);
+ debug("trying public RSA key file %s", file);
/* Fail quietly if file does not exist */
if (stat(file, &st) < 0) {
/* Restore the privileged uid. */
restore_uid();
+ xfree(file);
return 0;
}
/* Open the file containing the authorized keys. */
restore_uid();
packet_send_debug("Could not open %.900s for reading.", file);
packet_send_debug("If your home is on an NFS volume, it may need to be world-readable.");
+ xfree(file);
return 0;
}
- if (options.strict_modes) {
- int fail = 0;
- char buf[1024];
- /* Check open file in order to avoid open/stat races */
- if (fstat(fileno(f), &st) < 0 ||
- (st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
- (st.st_mode & 022) != 0) {
- snprintf(buf, sizeof buf, "RSA authentication refused for %.100s: "
- "bad ownership or modes for '%s'.", pw->pw_name, file);
- fail = 1;
- } else {
- /* Check path to SSH_USER_PERMITTED_KEYS */
- int i;
- static const char *check[] = {
- "", SSH_USER_DIR, NULL
- };
- for (i = 0; check[i]; i++) {
- snprintf(line, sizeof line, "%.500s/%.100s", pw->pw_dir, check[i]);
- if (stat(line, &st) < 0 ||
- (st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
- (st.st_mode & 022) != 0) {
- snprintf(buf, sizeof buf, "RSA authentication refused for %.100s: "
- "bad ownership or modes for '%s'.", pw->pw_name, line);
- fail = 1;
- break;
- }
- }
- }
- if (fail) {
- fclose(f);
- log(buf);
- packet_send_debug(buf);
- restore_uid();
- return 0;
- }
+ if (options.strict_modes &&
+ secure_filename(f, file, pw, line, sizeof(line)) != 0) {
+ xfree(file);
+ fclose(f);
+ log("Authentication refused: %s", line);
+ packet_send_debug("Authentication refused: %s", line);
+ restore_uid();
+ return 0;
}
/* Flag indicating whether authentication has succeeded. */
authenticated = 0;
/* Parse the key from the line. */
if (!auth_rsa_read_key(&cp, &bits, pk->e, pk->n)) {
- debug("%.100s, line %lu: bad key syntax",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: bad key syntax",
- SSH_USER_PERMITTED_KEYS, linenum);
+ debug("%.100s, line %lu: non ssh1 key syntax",
+ file, linenum);
continue;
}
/* cp now points to the comment part. */
/* check the real bits */
if (bits != BN_num_bits(pk->n))
- log("Warning: %s, line %ld: keysize mismatch: "
+ log("Warning: %s, line %lu: keysize mismatch: "
"actual %d vs. announced %d.",
file, linenum, BN_num_bits(pk->n), bits);
/* We have found the desired key. */
+ /*
+ * If our options do not allow this key to be used,
+ * do not send challenge.
+ */
+ if (!auth_parse_options(pw, options, file, linenum))
+ continue;
/* Perform the challenge-response dialog for this key. */
if (!auth_rsa_challenge_dialog(pk)) {
* Break out of the loop if authentication was successful;
* otherwise continue searching.
*/
- authenticated = auth_parse_options(pw, options, linenum);
- if (authenticated)
- break;
+ authenticated = 1;
+ break;
}
/* Restore the privileged uid. */
restore_uid();
/* Close the file. */
+ xfree(file);
fclose(f);
RSA_free(pk);
if (authenticated)
packet_send_debug("RSA authentication accepted.");
+ else
+ auth_clear_options();
/* Return authentication result. */
return authenticated;
andersk / openssh.git / blobdiff