version 1.8, 2000/05/08 17:42:24 |
version 1.8.2.3, 2001/03/12 15:44:08 |
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* 2. Redistributions in binary form must reproduce the above copyright |
* 2. Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* documentation and/or other materials provided with the distribution. |
* 3. All advertising materials mentioning features or use of this software |
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* must display the following acknowledgement: |
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* This product includes software developed by Markus Friedl. |
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* 4. The name of the author may not be used to endorse or promote products |
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* derived from this software without specific prior written permission. |
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* |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
*/ |
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#include "includes.h" |
#include "includes.h" |
RCSID("$OpenBSD$"); |
RCSID("$OpenBSD$"); |
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#include <openssl/dsa.h> |
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#include <openssl/rsa.h> |
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#include <openssl/evp.h> |
#include <openssl/evp.h> |
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#include "ssh2.h" |
#include "xmalloc.h" |
#include "xmalloc.h" |
#include "rsa.h" |
#include "rsa.h" |
#include "ssh.h" |
|
#include "pty.h" |
#include "pty.h" |
#include "packet.h" |
#include "packet.h" |
#include "buffer.h" |
#include "buffer.h" |
#include "cipher.h" |
#include "log.h" |
#include "servconf.h" |
#include "servconf.h" |
#include "compat.h" |
#include "compat.h" |
#include "channels.h" |
#include "channels.h" |
#include "bufaux.h" |
#include "bufaux.h" |
#include "ssh2.h" |
|
#include "auth.h" |
#include "auth.h" |
#include "session.h" |
#include "session.h" |
#include "dispatch.h" |
#include "dispatch.h" |
#include "auth.h" |
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#include "key.h" |
#include "key.h" |
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#include "cipher.h" |
#include "kex.h" |
#include "kex.h" |
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#include "pathnames.h" |
#include "dsa.h" |
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#include "uidswap.h" |
#include "uidswap.h" |
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#include "auth-options.h" |
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/* import */ |
/* import */ |
extern ServerOptions options; |
extern ServerOptions options; |
extern unsigned char *session_id2; |
extern u_char *session_id2; |
extern int session_id2_len; |
extern int session_id2_len; |
|
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/* protocol */ |
static Authctxt *x_authctxt = NULL; |
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static int one = 1; |
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void input_service_request(int type, int plen); |
typedef struct Authmethod Authmethod; |
void input_userauth_request(int type, int plen); |
struct Authmethod { |
void protocol_error(int type, int plen); |
char *name; |
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int (*userauth)(Authctxt *authctxt); |
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int *enabled; |
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}; |
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/* auth */ |
/* protocol */ |
int ssh2_auth_none(struct passwd *pw); |
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int ssh2_auth_password(struct passwd *pw); |
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int ssh2_auth_pubkey(struct passwd *pw, unsigned char *raw, unsigned int rlen); |
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|
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void input_service_request(int type, int plen, void *ctxt); |
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void input_userauth_request(int type, int plen, void *ctxt); |
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void protocol_error(int type, int plen, void *ctxt); |
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/* helper */ |
/* helper */ |
struct passwd* auth_set_user(char *u, char *s); |
Authmethod *authmethod_lookup(const char *name); |
int user_dsa_key_allowed(struct passwd *pw, Key *key); |
struct passwd *pwcopy(struct passwd *pw); |
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int user_key_allowed(struct passwd *pw, Key *key); |
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char *authmethods_get(void); |
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typedef struct Authctxt Authctxt; |
/* auth */ |
struct Authctxt { |
void userauth_banner(void); |
char *user; |
int userauth_none(Authctxt *authctxt); |
char *service; |
int userauth_passwd(Authctxt *authctxt); |
struct passwd pw; |
int userauth_pubkey(Authctxt *authctxt); |
int valid; |
int userauth_kbdint(Authctxt *authctxt); |
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|
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Authmethod authmethods[] = { |
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{"none", |
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userauth_none, |
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&one}, |
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{"publickey", |
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userauth_pubkey, |
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&options.pubkey_authentication}, |
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{"password", |
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userauth_passwd, |
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&options.password_authentication}, |
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{"keyboard-interactive", |
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userauth_kbdint, |
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&options.kbd_interactive_authentication}, |
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{NULL, NULL, NULL} |
}; |
}; |
static Authctxt *authctxt = NULL; |
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static int userauth_success = 0; |
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|
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/* |
/* |
* loop until userauth_success == TRUE |
* loop until authctxt->success == TRUE |
*/ |
*/ |
|
|
void |
void |
do_authentication2() |
do_authentication2() |
{ |
{ |
/* turn off skey/kerberos, not supported by SSH2 */ |
Authctxt *authctxt = authctxt_new(); |
#ifdef SKEY |
|
options.skey_authentication = 0; |
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#endif |
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#ifdef KRB4 |
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options.kerberos_authentication = 0; |
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#endif |
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x_authctxt = authctxt; /*XXX*/ |
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|
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/* challenge-reponse is implemented via keyboard interactive */ |
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if (options.challenge_reponse_authentication) |
|
options.kbd_interactive_authentication = 1; |
|
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dispatch_init(&protocol_error); |
dispatch_init(&protocol_error); |
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); |
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); |
dispatch_run(DISPATCH_BLOCK, &userauth_success); |
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt); |
do_authenticated2(); |
do_authenticated2(authctxt); |
} |
} |
|
|
void |
void |
protocol_error(int type, int plen) |
protocol_error(int type, int plen, void *ctxt) |
{ |
{ |
log("auth: protocol error: type %d plen %d", type, plen); |
log("auth: protocol error: type %d plen %d", type, plen); |
packet_start(SSH2_MSG_UNIMPLEMENTED); |
packet_start(SSH2_MSG_UNIMPLEMENTED); |
|
|
} |
} |
|
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void |
void |
input_service_request(int type, int plen) |
input_service_request(int type, int plen, void *ctxt) |
{ |
{ |
unsigned int len; |
Authctxt *authctxt = ctxt; |
|
u_int len; |
int accept = 0; |
int accept = 0; |
char *service = packet_get_string(&len); |
char *service = packet_get_string(&len); |
packet_done(); |
packet_done(); |
|
|
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if (authctxt == NULL) |
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fatal("input_service_request: no authctxt"); |
|
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if (strcmp(service, "ssh-userauth") == 0) { |
if (strcmp(service, "ssh-userauth") == 0) { |
if (!userauth_success) { |
if (!authctxt->success) { |
accept = 1; |
accept = 1; |
/* now we can handle user-auth requests */ |
/* now we can handle user-auth requests */ |
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); |
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); |
|
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} |
} |
|
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void |
void |
input_userauth_request(int type, int plen) |
input_userauth_request(int type, int plen, void *ctxt) |
{ |
{ |
static void (*authlog) (const char *fmt,...) = verbose; |
Authctxt *authctxt = ctxt; |
static int attempt = 0; |
Authmethod *m = NULL; |
unsigned int len, rlen; |
char *user, *service, *method, *style = NULL; |
int authenticated = 0; |
int authenticated = 0; |
char *raw, *user, *service, *method, *authmsg = NULL; |
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struct passwd *pw; |
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|
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if (++attempt == AUTH_FAIL_MAX) |
if (authctxt == NULL) |
packet_disconnect("too many failed userauth_requests"); |
fatal("input_userauth_request: no authctxt"); |
|
|
raw = packet_get_raw(&rlen); |
user = packet_get_string(NULL); |
if (plen != rlen) |
service = packet_get_string(NULL); |
fatal("plen != rlen"); |
method = packet_get_string(NULL); |
user = packet_get_string(&len); |
|
service = packet_get_string(&len); |
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method = packet_get_string(&len); |
|
debug("userauth-request for user %s service %s method %s", user, service, method); |
debug("userauth-request for user %s service %s method %s", user, service, method); |
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debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); |
|
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/* XXX we only allow the ssh-connection service */ |
if ((style = strchr(user, ':')) != NULL) |
pw = auth_set_user(user, service); |
*style++ = 0; |
if (pw && strcmp(service, "ssh-connection")==0) { |
|
if (strcmp(method, "none") == 0) { |
if (authctxt->attempt++ == 0) { |
authenticated = ssh2_auth_none(pw); |
/* setup auth context */ |
} else if (strcmp(method, "password") == 0) { |
struct passwd *pw = NULL; |
authenticated = ssh2_auth_password(pw); |
pw = getpwnam(user); |
} else if (strcmp(method, "publickey") == 0) { |
if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) { |
authenticated = ssh2_auth_pubkey(pw, raw, rlen); |
authctxt->pw = pwcopy(pw); |
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authctxt->valid = 1; |
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debug2("input_userauth_request: setting up authctxt for %s", user); |
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} else { |
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log("input_userauth_request: illegal user %s", user); |
} |
} |
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setproctitle("%s", pw ? user : "unknown"); |
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authctxt->user = xstrdup(user); |
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authctxt->service = xstrdup(service); |
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authctxt->style = style ? xstrdup(style) : NULL; /* currently unused */ |
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} else if (authctxt->valid) { |
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if (strcmp(user, authctxt->user) != 0 || |
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strcmp(service, authctxt->service) != 0) { |
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log("input_userauth_request: missmatch: (%s,%s)!=(%s,%s)", |
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user, service, authctxt->user, authctxt->service); |
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authctxt->valid = 0; |
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} |
} |
} |
if (authenticated && pw && pw->pw_uid == 0 && !options.permit_root_login) { |
/* reset state */ |
authenticated = 0; |
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error); |
log("ROOT LOGIN REFUSED FROM %.200s", |
authctxt->postponed = 0; |
get_canonical_hostname()); |
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/* try to authenticate user */ |
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m = authmethod_lookup(method); |
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if (m != NULL) { |
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debug2("input_userauth_request: try method %s", method); |
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authenticated = m->userauth(authctxt); |
} |
} |
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if (!authctxt->valid && authenticated) |
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fatal("INTERNAL ERROR: authenticated invalid user %s", |
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authctxt->user); |
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/* Raise logging level */ |
/* Special handling for root */ |
if (authenticated == 1 || |
if (authenticated && authctxt->pw->pw_uid == 0 && |
attempt == AUTH_FAIL_LOG || |
!auth_root_allowed(method)) |
strcmp(method, "password") == 0) |
authenticated = 0; |
authlog = log; |
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/* Log before sending the reply */ |
/* Log before sending the reply */ |
if (authenticated == 1) { |
auth_log(authctxt, authenticated, method, " ssh2"); |
authmsg = "Accepted"; |
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} else if (authenticated == 0) { |
if (!authctxt->postponed) |
authmsg = "Failed"; |
userauth_reply(authctxt, authenticated); |
} else { |
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authmsg = "Postponed"; |
xfree(service); |
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xfree(user); |
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xfree(method); |
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} |
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void |
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userauth_banner(void) |
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{ |
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struct stat st; |
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char *banner = NULL; |
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off_t len, n; |
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int fd; |
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if (options.banner == NULL || (datafellows & SSH_BUG_BANNER)) |
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return; |
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if ((fd = open(options.banner, O_RDONLY)) < 0) { |
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error("userauth_banner: open %s failed: %s", |
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options.banner, strerror(errno)); |
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return; |
} |
} |
authlog("%s %s for %.200s from %.200s port %d ssh2", |
if (fstat(fd, &st) < 0) |
authmsg, |
goto done; |
method, |
len = st.st_size; |
pw && pw->pw_uid == 0 ? "ROOT" : user, |
banner = xmalloc(len + 1); |
get_remote_ipaddr(), |
if ((n = read(fd, banner, len)) < 0) |
get_remote_port()); |
goto done; |
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banner[n] = '\0'; |
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packet_start(SSH2_MSG_USERAUTH_BANNER); |
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packet_put_cstring(banner); |
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packet_put_cstring(""); /* language, unused */ |
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packet_send(); |
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debug("userauth_banner: sent"); |
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done: |
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if (banner) |
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xfree(banner); |
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close(fd); |
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return; |
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} |
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void |
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userauth_reply(Authctxt *authctxt, int authenticated) |
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{ |
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char *methods; |
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/* XXX todo: check if multiple auth methods are needed */ |
/* XXX todo: check if multiple auth methods are needed */ |
if (authenticated == 1) { |
if (authenticated == 1) { |
/* turn off userauth */ |
/* turn off userauth */ |
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packet_send(); |
packet_send(); |
packet_write_wait(); |
packet_write_wait(); |
/* now we can break out */ |
/* now we can break out */ |
userauth_success = 1; |
authctxt->success = 1; |
} else if (authenticated == 0) { |
} else { |
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if (authctxt->failures++ > AUTH_FAIL_MAX) |
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packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
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methods = authmethods_get(); |
packet_start(SSH2_MSG_USERAUTH_FAILURE); |
packet_start(SSH2_MSG_USERAUTH_FAILURE); |
packet_put_cstring("publickey,password"); /* XXX dynamic */ |
packet_put_cstring(methods); |
packet_put_char(0); /* XXX partial success, unused */ |
packet_put_char(0); /* XXX partial success, unused */ |
packet_send(); |
packet_send(); |
packet_write_wait(); |
packet_write_wait(); |
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xfree(methods); |
} |
} |
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xfree(service); |
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xfree(user); |
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xfree(method); |
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} |
} |
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int |
int |
ssh2_auth_none(struct passwd *pw) |
userauth_none(Authctxt *authctxt) |
{ |
{ |
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/* disable method "none", only allowed one time */ |
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Authmethod *m = authmethod_lookup("none"); |
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if (m != NULL) |
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m->enabled = NULL; |
packet_done(); |
packet_done(); |
return auth_password(pw, ""); |
userauth_banner(); |
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return authctxt->valid ? auth_password(authctxt->pw, "") : 0; |
} |
} |
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int |
int |
ssh2_auth_password(struct passwd *pw) |
userauth_passwd(Authctxt *authctxt) |
{ |
{ |
char *password; |
char *password; |
int authenticated = 0; |
int authenticated = 0; |
int change; |
int change; |
unsigned int len; |
u_int len; |
change = packet_get_char(); |
change = packet_get_char(); |
if (change) |
if (change) |
log("password change not supported"); |
log("password change not supported"); |
password = packet_get_string(&len); |
password = packet_get_string(&len); |
packet_done(); |
packet_done(); |
if (options.password_authentication && |
if (authctxt->valid && |
auth_password(pw, password) == 1) |
auth_password(authctxt->pw, password) == 1) |
authenticated = 1; |
authenticated = 1; |
memset(password, 0, len); |
memset(password, 0, len); |
xfree(password); |
xfree(password); |
return authenticated; |
return authenticated; |
} |
} |
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int |
int |
ssh2_auth_pubkey(struct passwd *pw, unsigned char *raw, unsigned int rlen) |
userauth_kbdint(Authctxt *authctxt) |
{ |
{ |
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int authenticated = 0; |
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char *lang = NULL; |
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char *devs = NULL; |
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lang = packet_get_string(NULL); |
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devs = packet_get_string(NULL); |
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packet_done(); |
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debug("keyboard-interactive language %s devs %s", lang, devs); |
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if (options.challenge_reponse_authentication) |
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authenticated = auth2_challenge(authctxt, devs); |
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xfree(lang); |
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xfree(devs); |
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return authenticated; |
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} |
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int |
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userauth_pubkey(Authctxt *authctxt) |
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{ |
Buffer b; |
Buffer b; |
Key *key; |
Key *key; |
char *pkalg, *pkblob, *sig; |
char *pkalg, *pkblob, *sig; |
unsigned int alen, blen, slen; |
u_int alen, blen, slen; |
int have_sig; |
int have_sig, pktype; |
int authenticated = 0; |
int authenticated = 0; |
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if (options.dsa_authentication == 0) { |
if (!authctxt->valid) { |
debug("pubkey auth disabled"); |
debug2("userauth_pubkey: disabled because of invalid user"); |
return 0; |
return 0; |
} |
} |
if (datafellows & SSH_BUG_PUBKEYAUTH) { |
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log("bug compatibility with ssh-2.0.13 pubkey not implemented"); |
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return 0; |
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} |
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have_sig = packet_get_char(); |
have_sig = packet_get_char(); |
pkalg = packet_get_string(&alen); |
if (datafellows & SSH_BUG_PKAUTH) { |
if (strcmp(pkalg, KEX_DSS) != 0) { |
debug2("userauth_pubkey: SSH_BUG_PKAUTH"); |
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/* no explicit pkalg given */ |
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pkblob = packet_get_string(&blen); |
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buffer_init(&b); |
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buffer_append(&b, pkblob, blen); |
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/* so we have to extract the pkalg from the pkblob */ |
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pkalg = buffer_get_string(&b, &alen); |
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buffer_free(&b); |
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} else { |
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pkalg = packet_get_string(&alen); |
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pkblob = packet_get_string(&blen); |
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} |
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pktype = key_type_from_name(pkalg); |
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if (pktype == KEY_UNSPEC) { |
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/* this is perfectly legal */ |
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log("userauth_pubkey: unsupported public key algorithm: %s", pkalg); |
xfree(pkalg); |
xfree(pkalg); |
log("bad pkalg %s", pkalg); /*XXX*/ |
xfree(pkblob); |
return 0; |
return 0; |
} |
} |
pkblob = packet_get_string(&blen); |
key = key_from_blob(pkblob, blen); |
key = dsa_key_from_blob(pkblob, blen); |
|
if (key != NULL) { |
if (key != NULL) { |
if (have_sig) { |
if (have_sig) { |
sig = packet_get_string(&slen); |
sig = packet_get_string(&slen); |
packet_done(); |
packet_done(); |
buffer_init(&b); |
buffer_init(&b); |
buffer_append(&b, session_id2, session_id2_len); |
if (datafellows & SSH_OLD_SESSIONID) { |
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buffer_append(&b, session_id2, session_id2_len); |
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} else { |
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buffer_put_string(&b, session_id2, session_id2_len); |
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} |
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/* reconstruct packet */ |
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
if (slen + 4 > rlen) |
buffer_put_cstring(&b, authctxt->user); |
fatal("bad rlen/slen"); |
buffer_put_cstring(&b, |
buffer_append(&b, raw, rlen - slen - 4); |
datafellows & SSH_BUG_PKSERVICE ? |
#ifdef DEBUG_DSS |
"ssh-userauth" : |
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authctxt->service); |
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if (datafellows & SSH_BUG_PKAUTH) { |
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buffer_put_char(&b, have_sig); |
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} else { |
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buffer_put_cstring(&b, "publickey"); |
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buffer_put_char(&b, have_sig); |
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buffer_put_cstring(&b, key_ssh_name(key)); |
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} |
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buffer_put_string(&b, pkblob, blen); |
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#ifdef DEBUG_PK |
buffer_dump(&b); |
buffer_dump(&b); |
#endif |
#endif |
/* test for correct signature */ |
/* test for correct signature */ |
if (user_dsa_key_allowed(pw, key) && |
if (user_key_allowed(authctxt->pw, key) && |
dsa_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1) |
key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1) |
authenticated = 1; |
authenticated = 1; |
buffer_clear(&b); |
buffer_clear(&b); |
xfree(sig); |
xfree(sig); |
} else { |
} else { |
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debug("test whether pkalg/pkblob are acceptable"); |
packet_done(); |
packet_done(); |
debug("test key..."); |
|
/* test whether pkalg/pkblob are acceptable */ |
|
/* XXX fake reply and always send PK_OK ? */ |
/* XXX fake reply and always send PK_OK ? */ |
/* |
/* |
* XXX this allows testing whether a user is allowed |
* XXX this allows testing whether a user is allowed |
|
|
* if a user is not allowed to login. is this an |
* if a user is not allowed to login. is this an |
* issue? -markus |
* issue? -markus |
*/ |
*/ |
if (user_dsa_key_allowed(pw, key)) { |
if (user_key_allowed(authctxt->pw, key)) { |
packet_start(SSH2_MSG_USERAUTH_PK_OK); |
packet_start(SSH2_MSG_USERAUTH_PK_OK); |
packet_put_string(pkalg, alen); |
packet_put_string(pkalg, alen); |
packet_put_string(pkblob, blen); |
packet_put_string(pkblob, blen); |
packet_send(); |
packet_send(); |
packet_write_wait(); |
packet_write_wait(); |
authenticated = -1; |
authctxt->postponed = 1; |
} |
} |
} |
} |
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if (authenticated != 1) |
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auth_clear_options(); |
key_free(key); |
key_free(key); |
} |
} |
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debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg); |
xfree(pkalg); |
xfree(pkalg); |
xfree(pkblob); |
xfree(pkblob); |
return authenticated; |
return authenticated; |
} |
} |
|
|
/* set and get current user */ |
/* get current user */ |
|
|
struct passwd* |
struct passwd* |
auth_get_user(void) |
auth_get_user(void) |
{ |
{ |
return (authctxt != NULL && authctxt->valid) ? &authctxt->pw : NULL; |
return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL; |
} |
} |
|
|
struct passwd* |
#define DELIM "," |
auth_set_user(char *u, char *s) |
|
|
char * |
|
authmethods_get(void) |
{ |
{ |
struct passwd *pw, *copy; |
Authmethod *method = NULL; |
|
u_int size = 0; |
|
char *list; |
|
|
if (authctxt == NULL) { |
for (method = authmethods; method->name != NULL; method++) { |
authctxt = xmalloc(sizeof(*authctxt)); |
if (strcmp(method->name, "none") == 0) |
authctxt->valid = 0; |
continue; |
authctxt->user = xstrdup(u); |
if (method->enabled != NULL && *(method->enabled) != 0) { |
authctxt->service = xstrdup(s); |
if (size != 0) |
setproctitle("%s", u); |
size += strlen(DELIM); |
pw = getpwnam(u); |
size += strlen(method->name); |
if (!pw || !allowed_user(pw)) { |
|
log("auth_set_user: illegal user %s", u); |
|
return NULL; |
|
} |
} |
copy = &authctxt->pw; |
} |
memset(copy, 0, sizeof(*copy)); |
size++; /* trailing '\0' */ |
copy->pw_name = xstrdup(pw->pw_name); |
list = xmalloc(size); |
copy->pw_passwd = xstrdup(pw->pw_passwd); |
list[0] = '\0'; |
copy->pw_uid = pw->pw_uid; |
|
copy->pw_gid = pw->pw_gid; |
for (method = authmethods; method->name != NULL; method++) { |
copy->pw_dir = xstrdup(pw->pw_dir); |
if (strcmp(method->name, "none") == 0) |
copy->pw_shell = xstrdup(pw->pw_shell); |
continue; |
authctxt->valid = 1; |
if (method->enabled != NULL && *(method->enabled) != 0) { |
} else { |
if (list[0] != '\0') |
if (strcmp(u, authctxt->user) != 0 || |
strlcat(list, DELIM, size); |
strcmp(s, authctxt->service) != 0) { |
strlcat(list, method->name, size); |
log("auth_set_user: missmatch: (%s,%s)!=(%s,%s)", |
|
u, s, authctxt->user, authctxt->service); |
|
return NULL; |
|
} |
} |
} |
} |
return auth_get_user(); |
return list; |
} |
} |
|
|
|
Authmethod * |
|
authmethod_lookup(const char *name) |
|
{ |
|
Authmethod *method = NULL; |
|
if (name != NULL) |
|
for (method = authmethods; method->name != NULL; method++) |
|
if (method->enabled != NULL && |
|
*(method->enabled) != 0 && |
|
strcmp(name, method->name) == 0) |
|
return method; |
|
debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); |
|
return NULL; |
|
} |
|
|
/* return 1 if user allows given key */ |
/* return 1 if user allows given key */ |
int |
int |
user_dsa_key_allowed(struct passwd *pw, Key *key) |
user_key_allowed(struct passwd *pw, Key *key) |
{ |
{ |
char line[8192], file[1024]; |
char line[8192], file[MAXPATHLEN]; |
int found_key = 0; |
int found_key = 0; |
unsigned int bits = -1; |
|
FILE *f; |
FILE *f; |
unsigned long linenum = 0; |
u_long linenum = 0; |
struct stat st; |
struct stat st; |
Key *found; |
Key *found; |
|
|
|
if (pw == NULL) |
|
return 0; |
|
|
/* Temporarily use the user's uid. */ |
/* Temporarily use the user's uid. */ |
temporarily_use_uid(pw->pw_uid); |
temporarily_use_uid(pw->pw_uid); |
|
|
/* The authorized keys. */ |
/* The authorized keys. */ |
snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir, |
snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir, |
SSH_USER_PERMITTED_KEYS2); |
_PATH_SSH_USER_PERMITTED_KEYS2); |
|
|
/* Fail quietly if file does not exist */ |
/* Fail quietly if file does not exist */ |
if (stat(file, &st) < 0) { |
if (stat(file, &st) < 0) { |
|
|
if (fstat(fileno(f), &st) < 0 || |
if (fstat(fileno(f), &st) < 0 || |
(st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
(st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
(st.st_mode & 022) != 0) { |
(st.st_mode & 022) != 0) { |
snprintf(buf, sizeof buf, "DSA authentication refused for %.100s: " |
snprintf(buf, sizeof buf, |
"bad ownership or modes for '%s'.", pw->pw_name, file); |
"%s authentication refused for %.100s: " |
|
"bad ownership or modes for '%s'.", |
|
key_type(key), pw->pw_name, file); |
fail = 1; |
fail = 1; |
} else { |
} else { |
/* Check path to SSH_USER_PERMITTED_KEYS */ |
/* Check path to _PATH_SSH_USER_PERMITTED_KEYS */ |
int i; |
int i; |
static const char *check[] = { |
static const char *check[] = { |
"", SSH_USER_DIR, NULL |
"", _PATH_SSH_USER_DIR, NULL |
}; |
}; |
for (i = 0; check[i]; i++) { |
for (i = 0; check[i]; i++) { |
snprintf(line, sizeof line, "%.500s/%.100s", |
snprintf(line, sizeof line, "%.500s/%.100s", |
|
|
(st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
(st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
(st.st_mode & 022) != 0) { |
(st.st_mode & 022) != 0) { |
snprintf(buf, sizeof buf, |
snprintf(buf, sizeof buf, |
"DSA authentication refused for %.100s: " |
"%s authentication refused for %.100s: " |
"bad ownership or modes for '%s'.", |
"bad ownership or modes for '%s'.", |
pw->pw_name, line); |
key_type(key), pw->pw_name, line); |
fail = 1; |
fail = 1; |
break; |
break; |
} |
} |
} |
} |
} |
} |
if (fail) { |
if (fail) { |
log(buf); |
|
fclose(f); |
fclose(f); |
|
log("%s",buf); |
restore_uid(); |
restore_uid(); |
return 0; |
return 0; |
} |
} |
} |
} |
found_key = 0; |
found_key = 0; |
found = key_new(KEY_DSA); |
found = key_new(key->type); |
|
|
while (fgets(line, sizeof(line), f)) { |
while (fgets(line, sizeof(line), f)) { |
char *cp; |
char *cp, *options = NULL; |
linenum++; |
linenum++; |
/* Skip leading whitespace, empty and comment lines. */ |
/* Skip leading whitespace, empty and comment lines. */ |
for (cp = line; *cp == ' ' || *cp == '\t'; cp++) |
for (cp = line; *cp == ' ' || *cp == '\t'; cp++) |
; |
; |
if (!*cp || *cp == '\n' || *cp == '#') |
if (!*cp || *cp == '\n' || *cp == '#') |
continue; |
continue; |
bits = key_read(found, &cp); |
|
if (bits == 0) |
if (key_read(found, &cp) == -1) { |
continue; |
/* no key? check if there are options for this key */ |
if (key_equal(found, 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; |
found_key = 1; |
debug("matching key found: file %s, line %ld", |
debug("matching key found: file %s, line %ld", |
file, linenum); |
file, linenum); |