diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | Makefile.in | 4 | ||||
| -rw-r--r-- | auth.h | 9 | ||||
| -rw-r--r-- | auth2-hostbased.c | 182 | ||||
| -rw-r--r-- | auth2-kbdint.c | 69 | ||||
| -rw-r--r-- | auth2-none.c | 111 | ||||
| -rw-r--r-- | auth2-passwd.c | 65 | ||||
| -rw-r--r-- | auth2-pubkey.c | 283 | ||||
| -rw-r--r-- | auth2.c | 186 |
9 files changed, 726 insertions, 189 deletions
@@ -31,6 +31,10 @@ - markus@cvs.openbsd.org 2002/05/25 08:50:39 [sshconnect2.c] execlp->execl; from stevesk + - markus@cvs.openbsd.org 2002/05/25 18:51:07 + [auth.h auth2.c auth2-hostbased.c auth2-kbdint.c auth2-none.c + auth2-passwd.c auth2-pubkey.c Makefile.in] + split auth2.c into one file per method; ok provos@/deraadt@ 20020604 - (stevesk) [channels.c] bug #164 patch from YOSHIFUJI Hideaki (changed @@ -715,4 +719,4 @@ - (stevesk) entropy.c: typo in debug message - (djm) ssh-keygen -i needs seeded RNG; report from markus@ -$Id: ChangeLog,v 1.2152 2002/06/06 20:05:57 mouring Exp $ +$Id: ChangeLog,v 1.2153 2002/06/06 20:27:55 mouring Exp $ diff --git a/Makefile.in b/Makefile.in index ec235f82..4001d68a 100644 --- a/Makefile.in +++ b/Makefile.in @@ -1,4 +1,4 @@ -# $Id: Makefile.in,v 1.209 2002/06/06 19:57:33 mouring Exp $ +# $Id: Makefile.in,v 1.210 2002/06/06 20:27:55 mouring Exp $ # uncomment if you run a non bourne compatable shell. Ie. csh #SHELL = @SH@ @@ -61,7 +61,7 @@ LIBSSH_OBJS=atomicio.o authfd.o authfile.o bufaux.o buffer.o canohost.o channels SSHOBJS= ssh.o sshconnect.o sshconnect1.o sshconnect2.o sshtty.o readconf.o clientloop.o -SSHDOBJS= sshd.o auth.o auth1.o auth2.o auth-chall.o auth2-chall.o auth-rhosts.o auth-options.o auth-krb4.o auth-krb5.o auth-pam.o auth2-pam.o auth-passwd.o auth-rsa.o auth-rh-rsa.o auth-sia.o sshpty.o sshlogin.o loginrec.o servconf.o serverloop.o md5crypt.o session.o groupaccess.o auth-skey.o auth-bsdauth.o monitor_mm.o monitor.o +SSHDOBJS= sshd.o auth.o auth1.o auth2.o auth2-hostbased.o auth2-kbdint.o auth2-none.o auth2-passwd.o auth2-pubkey.o auth-chall.o auth2-chall.o auth-rhosts.o auth-options.o auth-krb4.o auth-krb5.o auth-pam.o auth2-pam.o auth-passwd.o auth-rsa.o auth-rh-rsa.o auth-sia.o sshpty.o sshlogin.o loginrec.o servconf.o serverloop.o md5crypt.o session.o groupaccess.o auth-skey.o auth-bsdauth.o monitor_mm.o monitor.o MANPAGES = scp.1.out ssh-add.1.out ssh-agent.1.out ssh-keygen.1.out ssh-keyscan.1.out ssh.1.out sshd.8.out sftp-server.8.out sftp.1.out ssh-rand-helper.8.out MANPAGES_IN = scp.1 ssh-add.1 ssh-agent.1 ssh-keygen.1 ssh-keyscan.1 ssh.1 sshd.8 sftp-server.8 sftp.1 ssh-rand-helper.8 @@ -1,4 +1,4 @@ -/* $OpenBSD: auth.h,v 1.37 2002/05/13 20:44:58 markus Exp $ */ +/* $OpenBSD: auth.h,v 1.38 2002/05/25 18:51:07 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -100,6 +100,13 @@ BIGNUM *auth_rsa_generate_challenge(Key *); int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]); int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **); +/* ssh2 methods */ +int userauth_none(Authctxt *); +int userauth_passwd(Authctxt *); +int userauth_pubkey(Authctxt *); +int userauth_hostbased(Authctxt *); +int userauth_kbdint(Authctxt *); + int auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *); int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); int user_key_allowed(struct passwd *, Key *); diff --git a/auth2-hostbased.c b/auth2-hostbased.c new file mode 100644 index 00000000..2bde7bb7 --- /dev/null +++ b/auth2-hostbased.c @@ -0,0 +1,182 @@ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +RCSID("$OpenBSD: auth2-hostbased.c,v 1.2 2002/05/31 11:35:15 markus Exp $"); + +#include "ssh2.h" +#include "xmalloc.h" +#include "packet.h" +#include "buffer.h" +#include "log.h" +#include "servconf.h" +#include "compat.h" +#include "bufaux.h" +#include "auth.h" +#include "key.h" +#include "canohost.h" +#include "monitor_wrap.h" +#include "pathnames.h" + +/* import */ +extern ServerOptions options; +extern u_char *session_id2; +extern int session_id2_len; + +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; +} + +/* 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); +} + +Authmethod method_hostbased = { + "hostbased", + userauth_hostbased, + &options.hostbased_authentication +}; diff --git a/auth2-kbdint.c b/auth2-kbdint.c new file mode 100644 index 00000000..e6099288 --- /dev/null +++ b/auth2-kbdint.c @@ -0,0 +1,69 @@ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +RCSID("$OpenBSD: auth2-kbdint.c,v 1.2 2002/05/31 11:35:15 markus Exp $"); + +#include "packet.h" +#include "auth.h" +#include "log.h" +#include "servconf.h" +#include "xmalloc.h" + +/* import */ +extern ServerOptions options; + +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); + +#ifdef USE_PAM + if (authenticated == 0 && options.pam_authentication_via_kbd_int) + authenticated = auth2_pam(authctxt); +#endif + xfree(devs); + xfree(lang); +#ifdef HAVE_CYGWIN + if (check_nt_auth(0, authctxt->pw) == 0) + return(0); +#endif + return authenticated; +} + +Authmethod method_kbdint = { + "keyboard-interactive", + userauth_kbdint, + &options.kbd_interactive_authentication +}; diff --git a/auth2-none.c b/auth2-none.c new file mode 100644 index 00000000..30337fd6 --- /dev/null +++ b/auth2-none.c @@ -0,0 +1,111 @@ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +RCSID("$OpenBSD: auth2-none.c,v 1.2 2002/05/31 11:35:15 markus Exp $"); + +#include "auth.h" +#include "xmalloc.h" +#include "packet.h" +#include "log.h" +#include "servconf.h" +#include "atomicio.h" +#include "compat.h" +#include "ssh2.h" +#include "monitor_wrap.h" + +/* import */ +extern ServerOptions options; + +/* "none" is allowed only one time */ +static int none_enabled = 1; + +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) +{ + none_enabled = 0; + packet_check_eom(); + userauth_banner(); +#ifdef HAVE_CYGWIN + if (check_nt_auth(1, authctxt->pw) == 0) + return(0); +#endif + return (authctxt->valid ? PRIVSEP(auth_password(authctxt, "")) : 0); +} + +Authmethod method_none = { + "none", + userauth_none, + &none_enabled +}; diff --git a/auth2-passwd.c b/auth2-passwd.c new file mode 100644 index 00000000..ffa27959 --- /dev/null +++ b/auth2-passwd.c @@ -0,0 +1,65 @@ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +RCSID("$OpenBSD: auth2-passwd.c,v 1.2 2002/05/31 11:35:15 markus Exp $"); + +#include "xmalloc.h" +#include "packet.h" +#include "log.h" +#include "auth.h" +#include "monitor_wrap.h" +#include "servconf.h" + +/* import */ +extern ServerOptions options; + +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 && +#ifdef HAVE_CYGWIN + check_nt_auth(1, authctxt->pw) && +#endif + PRIVSEP(auth_password(authctxt, password)) == 1) + authenticated = 1; + memset(password, 0, len); + xfree(password); + return authenticated; +} + +Authmethod method_passwd = { + "password", + userauth_passwd, + &options.password_authentication +}; diff --git a/auth2-pubkey.c b/auth2-pubkey.c new file mode 100644 index 00000000..947bfed0 --- /dev/null +++ b/auth2-pubkey.c @@ -0,0 +1,283 @@ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +RCSID("$OpenBSD: auth2-pubkey.c,v 1.2 2002/05/31 11:35:15 markus Exp $"); + +#include "ssh2.h" +#include "xmalloc.h" +#include "packet.h" +#include "buffer.h" +#include "log.h" +#include "servconf.h" +#include "compat.h" +#include "bufaux.h" +#include "auth.h" +#include "key.h" +#include "pathnames.h" +#include "uidswap.h" +#include "auth-options.h" +#include "canohost.h" +#include "monitor_wrap.h" + +/* import */ +extern ServerOptions options; +extern u_char *session_id2; +extern int session_id2_len; + +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); +#ifdef HAVE_CYGWIN + if (check_nt_auth(0, authctxt->pw) == 0) + return(0); +#endif + return authenticated; +} + +/* 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; +} + +Authmethod method_pubkey = { + "publickey", + userauth_pubkey, + &options.pubkey_authentication +}; @@ -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", @@ -651,164 +628,3 @@ 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); -} |