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Diffstat (limited to 'usr.bin/ssh/auth2.c')
-rw-r--r--usr.bin/ssh/auth2.c484
1 files changed, 1 insertions, 483 deletions
diff --git a/usr.bin/ssh/auth2.c b/usr.bin/ssh/auth2.c
index 6da2423cb77..2ac328055ee 100644
--- a/usr.bin/ssh/auth2.c
+++ b/usr.bin/ssh/auth2.c
@@ -23,35 +23,18 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.91 2002/05/13 02:37:39 itojun Exp $");
-
-#include <openssl/evp.h>
+RCSID("$OpenBSD: auth2.c,v 1.92 2002/05/25 18:51:07 markus Exp $");
#include "ssh2.h"
#include "xmalloc.h"
-#include "rsa.h"
-#include "sshpty.h"
#include "packet.h"
-#include "buffer.h"
#include "log.h"
#include "servconf.h"
#include "compat.h"
-#include "channels.h"
-#include "bufaux.h"
#include "auth.h"
-#include "session.h"
#include "dispatch.h"
-#include "key.h"
-#include "cipher.h"
-#include "kex.h"
#include "pathnames.h"
-#include "uidswap.h"
-#include "auth-options.h"
-#include "hostfile.h"
-#include "canohost.h"
-#include "match.h"
#include "monitor_wrap.h"
-#include "atomicio.h"
/* import */
extern ServerOptions options;
@@ -80,12 +63,6 @@ int user_key_allowed(struct passwd *, Key *);
int hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
/* auth */
-static void userauth_banner(void);
-static int userauth_none(Authctxt *);
-static int userauth_passwd(Authctxt *);
-static int userauth_pubkey(Authctxt *);
-static int userauth_hostbased(Authctxt *);
-static int userauth_kbdint(Authctxt *);
Authmethod authmethods[] = {
{"none",
@@ -262,304 +239,6 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method)
}
}
-char *
-auth2_read_banner(void)
-{
- struct stat st;
- char *banner = NULL;
- off_t len, n;
- int fd;
-
- if ((fd = open(options.banner, O_RDONLY)) == -1)
- return (NULL);
- if (fstat(fd, &st) == -1) {
- close(fd);
- return (NULL);
- }
- len = st.st_size;
- banner = xmalloc(len + 1);
- n = atomicio(read, fd, banner, len);
- close(fd);
-
- if (n != len) {
- free(banner);
- return (NULL);
- }
- banner[n] = '\0';
-
- return (banner);
-}
-
-static void
-userauth_banner(void)
-{
- char *banner = NULL;
-
- if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
- return;
-
- if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
- goto done;
-
- packet_start(SSH2_MSG_USERAUTH_BANNER);
- packet_put_cstring(banner);
- packet_put_cstring(""); /* language, unused */
- packet_send();
- debug("userauth_banner: sent");
-done:
- if (banner)
- xfree(banner);
- return;
-}
-
-static int
-userauth_none(Authctxt *authctxt)
-{
- /* disable method "none", only allowed one time */
- Authmethod *m = authmethod_lookup("none");
- if (m != NULL)
- m->enabled = NULL;
- packet_check_eom();
- userauth_banner();
- return (authctxt->valid ? PRIVSEP(auth_password(authctxt, "")) : 0);
-}
-
-static int
-userauth_passwd(Authctxt *authctxt)
-{
- char *password;
- int authenticated = 0;
- int change;
- u_int len;
- change = packet_get_char();
- if (change)
- log("password change not supported");
- password = packet_get_string(&len);
- packet_check_eom();
- if (authctxt->valid &&
- PRIVSEP(auth_password(authctxt, password)) == 1)
- authenticated = 1;
- memset(password, 0, len);
- xfree(password);
- return authenticated;
-}
-
-static int
-userauth_kbdint(Authctxt *authctxt)
-{
- int authenticated = 0;
- char *lang, *devs;
-
- lang = packet_get_string(NULL);
- devs = packet_get_string(NULL);
- packet_check_eom();
-
- debug("keyboard-interactive devs %s", devs);
-
- if (options.challenge_response_authentication)
- authenticated = auth2_challenge(authctxt, devs);
-
- xfree(devs);
- xfree(lang);
- return authenticated;
-}
-
-static int
-userauth_pubkey(Authctxt *authctxt)
-{
- Buffer b;
- Key *key = NULL;
- char *pkalg;
- u_char *pkblob, *sig;
- u_int alen, blen, slen;
- int have_sig, pktype;
- int authenticated = 0;
-
- if (!authctxt->valid) {
- debug2("userauth_pubkey: disabled because of invalid user");
- return 0;
- }
- have_sig = packet_get_char();
- if (datafellows & SSH_BUG_PKAUTH) {
- debug2("userauth_pubkey: SSH_BUG_PKAUTH");
- /* no explicit pkalg given */
- pkblob = packet_get_string(&blen);
- buffer_init(&b);
- buffer_append(&b, pkblob, blen);
- /* so we have to extract the pkalg from the pkblob */
- pkalg = buffer_get_string(&b, &alen);
- buffer_free(&b);
- } else {
- pkalg = packet_get_string(&alen);
- pkblob = packet_get_string(&blen);
- }
- pktype = key_type_from_name(pkalg);
- if (pktype == KEY_UNSPEC) {
- /* this is perfectly legal */
- log("userauth_pubkey: unsupported public key algorithm: %s",
- pkalg);
- goto done;
- }
- key = key_from_blob(pkblob, blen);
- if (key == NULL) {
- error("userauth_pubkey: cannot decode key: %s", pkalg);
- goto done;
- }
- if (key->type != pktype) {
- error("userauth_pubkey: type mismatch for decoded key "
- "(received %d, expected %d)", key->type, pktype);
- goto done;
- }
- if (have_sig) {
- sig = packet_get_string(&slen);
- packet_check_eom();
- buffer_init(&b);
- if (datafellows & SSH_OLD_SESSIONID) {
- buffer_append(&b, session_id2, session_id2_len);
- } else {
- buffer_put_string(&b, session_id2, session_id2_len);
- }
- /* reconstruct packet */
- buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
- buffer_put_cstring(&b,
- datafellows & SSH_BUG_PKSERVICE ?
- "ssh-userauth" :
- authctxt->service);
- if (datafellows & SSH_BUG_PKAUTH) {
- buffer_put_char(&b, have_sig);
- } else {
- buffer_put_cstring(&b, "publickey");
- buffer_put_char(&b, have_sig);
- buffer_put_cstring(&b, pkalg);
- }
- buffer_put_string(&b, pkblob, blen);
-#ifdef DEBUG_PK
- buffer_dump(&b);
-#endif
- /* test for correct signature */
- authenticated = 0;
- if (PRIVSEP(user_key_allowed(authctxt->pw, key)) &&
- PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
- buffer_len(&b))) == 1)
- authenticated = 1;
- buffer_clear(&b);
- xfree(sig);
- } else {
- debug("test whether pkalg/pkblob are acceptable");
- packet_check_eom();
-
- /* XXX fake reply and always send PK_OK ? */
- /*
- * XXX this allows testing whether a user is allowed
- * to login: if you happen to have a valid pubkey this
- * message is sent. the message is NEVER sent at all
- * if a user is not allowed to login. is this an
- * issue? -markus
- */
- if (PRIVSEP(user_key_allowed(authctxt->pw, key))) {
- packet_start(SSH2_MSG_USERAUTH_PK_OK);
- packet_put_string(pkalg, alen);
- packet_put_string(pkblob, blen);
- packet_send();
- packet_write_wait();
- authctxt->postponed = 1;
- }
- }
- if (authenticated != 1)
- auth_clear_options();
-done:
- debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
- if (key != NULL)
- key_free(key);
- xfree(pkalg);
- xfree(pkblob);
- return authenticated;
-}
-
-static int
-userauth_hostbased(Authctxt *authctxt)
-{
- Buffer b;
- Key *key = NULL;
- char *pkalg, *cuser, *chost, *service;
- u_char *pkblob, *sig;
- u_int alen, blen, slen;
- int pktype;
- int authenticated = 0;
-
- if (!authctxt->valid) {
- debug2("userauth_hostbased: disabled because of invalid user");
- return 0;
- }
- pkalg = packet_get_string(&alen);
- pkblob = packet_get_string(&blen);
- chost = packet_get_string(NULL);
- cuser = packet_get_string(NULL);
- sig = packet_get_string(&slen);
-
- debug("userauth_hostbased: cuser %s chost %s pkalg %s slen %d",
- cuser, chost, pkalg, slen);
-#ifdef DEBUG_PK
- debug("signature:");
- buffer_init(&b);
- buffer_append(&b, sig, slen);
- buffer_dump(&b);
- buffer_free(&b);
-#endif
- pktype = key_type_from_name(pkalg);
- if (pktype == KEY_UNSPEC) {
- /* this is perfectly legal */
- log("userauth_hostbased: unsupported "
- "public key algorithm: %s", pkalg);
- goto done;
- }
- key = key_from_blob(pkblob, blen);
- if (key == NULL) {
- error("userauth_hostbased: cannot decode key: %s", pkalg);
- goto done;
- }
- if (key->type != pktype) {
- error("userauth_hostbased: type mismatch for decoded key "
- "(received %d, expected %d)", key->type, pktype);
- goto done;
- }
- service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
- authctxt->service;
- buffer_init(&b);
- buffer_put_string(&b, session_id2, session_id2_len);
- /* reconstruct packet */
- buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
- buffer_put_cstring(&b, service);
- buffer_put_cstring(&b, "hostbased");
- buffer_put_string(&b, pkalg, alen);
- buffer_put_string(&b, pkblob, blen);
- buffer_put_cstring(&b, chost);
- buffer_put_cstring(&b, cuser);
-#ifdef DEBUG_PK
- buffer_dump(&b);
-#endif
- /* test for allowed key and correct signature */
- authenticated = 0;
- if (PRIVSEP(hostbased_key_allowed(authctxt->pw, cuser, chost, key)) &&
- PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
- buffer_len(&b))) == 1)
- authenticated = 1;
-
- buffer_clear(&b);
-done:
- debug2("userauth_hostbased: authenticated %d", authenticated);
- if (key != NULL)
- key_free(key);
- xfree(pkalg);
- xfree(pkblob);
- xfree(cuser);
- xfree(chost);
- xfree(sig);
- return authenticated;
-}
-
/* get current user */
struct passwd*
@@ -606,164 +285,3 @@ authmethod_lookup(const char *name)
debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
return NULL;
}
-
-/* return 1 if user allows given key */
-static int
-user_key_allowed2(struct passwd *pw, Key *key, char *file)
-{
- char line[8192];
- int found_key = 0;
- FILE *f;
- u_long linenum = 0;
- struct stat st;
- Key *found;
- char *fp;
-
- if (pw == NULL)
- return 0;
-
- /* Temporarily use the user's uid. */
- temporarily_use_uid(pw);
-
- debug("trying public key file %s", file);
-
- /* Fail quietly if file does not exist */
- if (stat(file, &st) < 0) {
- /* Restore the privileged uid. */
- restore_uid();
- return 0;
- }
- /* Open the file containing the authorized keys. */
- f = fopen(file, "r");
- if (!f) {
- /* Restore the privileged uid. */
- restore_uid();
- return 0;
- }
- if (options.strict_modes &&
- secure_filename(f, file, pw, line, sizeof(line)) != 0) {
- fclose(f);
- log("Authentication refused: %s", line);
- restore_uid();
- return 0;
- }
-
- found_key = 0;
- found = key_new(key->type);
-
- while (fgets(line, sizeof(line), f)) {
- char *cp, *options = NULL;
- linenum++;
- /* Skip leading whitespace, empty and comment lines. */
- for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
- ;
- if (!*cp || *cp == '\n' || *cp == '#')
- continue;
-
- if (key_read(found, &cp) != 1) {
- /* no key? check if there are options for this key */
- int quoted = 0;
- debug2("user_key_allowed: check options: '%s'", cp);
- options = cp;
- for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
- if (*cp == '\\' && cp[1] == '"')
- cp++; /* Skip both */
- else if (*cp == '"')
- quoted = !quoted;
- }
- /* Skip remaining whitespace. */
- for (; *cp == ' ' || *cp == '\t'; cp++)
- ;
- if (key_read(found, &cp) != 1) {
- debug2("user_key_allowed: advance: '%s'", cp);
- /* still no key? advance to next line*/
- continue;
- }
- }
- if (key_equal(found, key) &&
- auth_parse_options(pw, options, file, linenum) == 1) {
- found_key = 1;
- debug("matching key found: file %s, line %lu",
- file, linenum);
- fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
- verbose("Found matching %s key: %s",
- key_type(found), fp);
- xfree(fp);
- break;
- }
- }
- restore_uid();
- fclose(f);
- key_free(found);
- if (!found_key)
- debug2("key not found");
- return found_key;
-}
-
-/* check whether given key is in .ssh/authorized_keys* */
-int
-user_key_allowed(struct passwd *pw, Key *key)
-{
- int success;
- char *file;
-
- file = authorized_keys_file(pw);
- success = user_key_allowed2(pw, key, file);
- xfree(file);
- if (success)
- return success;
-
- /* try suffix "2" for backward compat, too */
- file = authorized_keys_file2(pw);
- success = user_key_allowed2(pw, key, file);
- xfree(file);
- return success;
-}
-
-/* return 1 if given hostkey is allowed */
-int
-hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
- Key *key)
-{
- const char *resolvedname, *ipaddr, *lookup;
- HostStatus host_status;
- int len;
-
- resolvedname = get_canonical_hostname(options.verify_reverse_mapping);
- ipaddr = get_remote_ipaddr();
-
- debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s",
- chost, resolvedname, ipaddr);
-
- if (options.hostbased_uses_name_from_packet_only) {
- if (auth_rhosts2(pw, cuser, chost, chost) == 0)
- return 0;
- lookup = chost;
- } else {
- if (((len = strlen(chost)) > 0) && chost[len - 1] == '.') {
- debug2("stripping trailing dot from chost %s", chost);
- chost[len - 1] = '\0';
- }
- if (strcasecmp(resolvedname, chost) != 0)
- log("userauth_hostbased mismatch: "
- "client sends %s, but we resolve %s to %s",
- chost, ipaddr, resolvedname);
- if (auth_rhosts2(pw, cuser, resolvedname, ipaddr) == 0)
- return 0;
- lookup = resolvedname;
- }
- debug2("userauth_hostbased: access allowed by auth_rhosts2");
-
- host_status = check_key_in_hostfiles(pw, key, lookup,
- _PATH_SSH_SYSTEM_HOSTFILE,
- options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
-
- /* backward compat if no key has been found. */
- if (host_status == HOST_NEW)
- host_status = check_key_in_hostfiles(pw, key, lookup,
- _PATH_SSH_SYSTEM_HOSTFILE2,
- options.ignore_user_known_hosts ? NULL :
- _PATH_SSH_USER_HOSTFILE2);
-
- return (host_status == HOST_OK);
-}
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