version 1.20, 2000/10/14 12:16:56 |
version 1.20.2.2, 2001/02/19 17:18:39 |
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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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|
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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 "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" |
#include "auth-options.h" |
#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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static Authctxt *x_authctxt = NULL; |
static Authctxt *x_authctxt = NULL; |
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void input_userauth_request(int type, int plen, void *ctxt); |
void input_userauth_request(int type, int plen, void *ctxt); |
void protocol_error(int type, int plen, void *ctxt); |
void protocol_error(int type, int plen, void *ctxt); |
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|
|
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/* helper */ |
/* helper */ |
Authmethod *authmethod_lookup(const char *name); |
Authmethod *authmethod_lookup(const char *name); |
struct passwd *pwcopy(struct passwd *pw); |
struct passwd *pwcopy(struct passwd *pw); |
int user_dsa_key_allowed(struct passwd *pw, Key *key); |
int user_key_allowed(struct passwd *pw, Key *key); |
char *authmethods_get(void); |
char *authmethods_get(void); |
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/* auth */ |
/* auth */ |
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void userauth_banner(void); |
int userauth_none(Authctxt *authctxt); |
int userauth_none(Authctxt *authctxt); |
int userauth_passwd(Authctxt *authctxt); |
int userauth_passwd(Authctxt *authctxt); |
int userauth_pubkey(Authctxt *authctxt); |
int userauth_pubkey(Authctxt *authctxt); |
|
|
&one}, |
&one}, |
{"publickey", |
{"publickey", |
userauth_pubkey, |
userauth_pubkey, |
&options.dsa_authentication}, |
&options.pubkey_authentication}, |
{"keyboard-interactive", |
|
userauth_kbdint, |
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&options.kbd_interactive_authentication}, |
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{"password", |
{"password", |
userauth_passwd, |
userauth_passwd, |
&options.password_authentication}, |
&options.password_authentication}, |
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{"keyboard-interactive", |
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userauth_kbdint, |
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&options.kbd_interactive_authentication}, |
{NULL, NULL, NULL} |
{NULL, NULL, NULL} |
}; |
}; |
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|
|
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void |
void |
do_authentication2() |
do_authentication2() |
{ |
{ |
Authctxt *authctxt = xmalloc(sizeof(*authctxt)); |
Authctxt *authctxt = authctxt_new(); |
memset(authctxt, 'a', sizeof(*authctxt)); |
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authctxt->valid = 0; |
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authctxt->attempt = 0; |
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authctxt->success = 0; |
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x_authctxt = authctxt; /*XXX*/ |
x_authctxt = authctxt; /*XXX*/ |
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#ifdef KRB4 |
/* challenge-reponse is implemented via keyboard interactive */ |
/* turn off kerberos, not supported by SSH2 */ |
if (options.challenge_reponse_authentication) |
options.kerberos_authentication = 0; |
options.kbd_interactive_authentication = 1; |
#endif |
|
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, &authctxt->success, authctxt); |
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt); |
do_authenticated2(); |
do_authenticated2(authctxt); |
} |
} |
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void |
void |
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input_service_request(int type, int plen, void *ctxt) |
input_service_request(int type, int plen, void *ctxt) |
{ |
{ |
Authctxt *authctxt = ctxt; |
Authctxt *authctxt = ctxt; |
unsigned int len; |
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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{ |
{ |
Authctxt *authctxt = ctxt; |
Authctxt *authctxt = ctxt; |
Authmethod *m = NULL; |
Authmethod *m = NULL; |
char *user, *service, *method; |
char *user, *service, *method, *style = NULL; |
int authenticated = 0; |
int authenticated = 0; |
|
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if (authctxt == NULL) |
if (authctxt == NULL) |
fatal("input_userauth_request: no authctxt"); |
fatal("input_userauth_request: no authctxt"); |
if (authctxt->attempt++ >= AUTH_FAIL_MAX) |
|
packet_disconnect("too many failed userauth_requests"); |
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|
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user = packet_get_string(NULL); |
user = packet_get_string(NULL); |
service = packet_get_string(NULL); |
service = packet_get_string(NULL); |
method = packet_get_string(NULL); |
method = packet_get_string(NULL); |
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); |
debug("attempt #%d", authctxt->attempt); |
debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); |
|
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if (authctxt->attempt == 1) { |
if ((style = strchr(user, ':')) != NULL) |
|
*style++ = 0; |
|
|
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if (authctxt->attempt++ == 0) { |
/* setup auth context */ |
/* setup auth context */ |
struct passwd *pw = NULL; |
struct passwd *pw = NULL; |
setproctitle("%s", user); |
|
pw = getpwnam(user); |
pw = getpwnam(user); |
if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) { |
if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) { |
authctxt->pw = pwcopy(pw); |
authctxt->pw = pwcopy(pw); |
|
|
} else { |
} else { |
log("input_userauth_request: illegal user %s", user); |
log("input_userauth_request: illegal user %s", user); |
} |
} |
|
setproctitle("%s", pw ? user : "unknown"); |
authctxt->user = xstrdup(user); |
authctxt->user = xstrdup(user); |
authctxt->service = xstrdup(service); |
authctxt->service = xstrdup(service); |
|
authctxt->style = style ? xstrdup(style) : NULL; /* currently unused */ |
} else if (authctxt->valid) { |
} else if (authctxt->valid) { |
if (strcmp(user, authctxt->user) != 0 || |
if (strcmp(user, authctxt->user) != 0 || |
strcmp(service, authctxt->service) != 0) { |
strcmp(service, authctxt->service) != 0) { |
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authctxt->valid = 0; |
authctxt->valid = 0; |
} |
} |
} |
} |
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/* reset state */ |
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dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error); |
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authctxt->postponed = 0; |
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/* try to authenticate user */ |
m = authmethod_lookup(method); |
m = authmethod_lookup(method); |
if (m != NULL) { |
if (m != NULL) { |
debug2("input_userauth_request: try method %s", method); |
debug2("input_userauth_request: try method %s", method); |
authenticated = m->userauth(authctxt); |
authenticated = m->userauth(authctxt); |
} else { |
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debug2("input_userauth_request: unsupported method %s", method); |
|
} |
} |
if (!authctxt->valid && authenticated == 1) { |
if (!authctxt->valid && authenticated) |
log("input_userauth_request: INTERNAL ERROR: authenticated invalid user %s service %s", user, method); |
fatal("INTERNAL ERROR: authenticated invalid user %s", |
authenticated = 0; |
authctxt->user); |
} |
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/* Special handling for root */ |
/* Special handling for root */ |
if (authenticated == 1 && |
if (authenticated && authctxt->pw->pw_uid == 0 && |
authctxt->valid && authctxt->pw->pw_uid == 0 && !options.permit_root_login) { |
!auth_root_allowed(method)) |
authenticated = 0; |
authenticated = 0; |
log("ROOT LOGIN REFUSED FROM %.200s", get_canonical_hostname()); |
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} |
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/* Log before sending the reply */ |
/* Log before sending the reply */ |
userauth_log(authctxt, authenticated, method); |
auth_log(authctxt, authenticated, method, " ssh2"); |
userauth_reply(authctxt, authenticated); |
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if (!authctxt->postponed) |
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userauth_reply(authctxt, authenticated); |
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xfree(service); |
xfree(service); |
xfree(user); |
xfree(user); |
xfree(method); |
xfree(method); |
} |
} |
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void |
void |
userauth_log(Authctxt *authctxt, int authenticated, char *method) |
userauth_banner(void) |
{ |
{ |
void (*authlog) (const char *fmt,...) = verbose; |
struct stat st; |
char *user = NULL, *authmsg = NULL; |
char *banner = NULL; |
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off_t len, n; |
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int fd; |
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/* Raise logging level */ |
if (options.banner == NULL || (datafellows & SSH_BUG_BANNER)) |
if (authenticated == 1 || |
return; |
!authctxt->valid || |
if ((fd = open(options.banner, O_RDONLY)) < 0) { |
authctxt->attempt >= AUTH_FAIL_LOG || |
error("userauth_banner: open %s failed: %s", |
strcmp(method, "password") == 0) |
options.banner, strerror(errno)); |
authlog = log; |
return; |
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if (authenticated == 1) { |
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authmsg = "Accepted"; |
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} else if (authenticated == 0) { |
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authmsg = "Failed"; |
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} else { |
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authmsg = "Postponed"; |
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} |
} |
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if (fstat(fd, &st) < 0) |
if (authctxt->valid) { |
goto done; |
user = authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user; |
len = st.st_size; |
} else { |
banner = xmalloc(len + 1); |
user = "NOUSER"; |
if ((n = read(fd, banner, len)) < 0) |
} |
goto done; |
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banner[n] = '\0'; |
authlog("%s %s for %.200s from %.200s port %d ssh2", |
packet_start(SSH2_MSG_USERAUTH_BANNER); |
authmsg, |
packet_put_cstring(banner); |
method, |
packet_put_cstring(""); /* language, unused */ |
user, |
packet_send(); |
get_remote_ipaddr(), |
debug("userauth_banner: sent"); |
get_remote_port()); |
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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void |
void |
userauth_reply(Authctxt *authctxt, int authenticated) |
userauth_reply(Authctxt *authctxt, int authenticated) |
{ |
{ |
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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_write_wait(); |
packet_write_wait(); |
/* now we can break out */ |
/* now we can break out */ |
authctxt->success = 1; |
authctxt->success = 1; |
} else if (authenticated == 0) { |
} else { |
char *methods = authmethods_get(); |
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(methods); |
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(); |
xfree(methods); |
xfree(methods); |
} else { |
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/* do nothing, we did already send a reply */ |
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} |
} |
} |
} |
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if (m != NULL) |
if (m != NULL) |
m->enabled = NULL; |
m->enabled = NULL; |
packet_done(); |
packet_done(); |
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userauth_banner(); |
return authctxt->valid ? auth_password(authctxt->pw, "") : 0; |
return authctxt->valid ? auth_password(authctxt->pw, "") : 0; |
} |
} |
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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"); |
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packet_done(); |
packet_done(); |
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debug("keyboard-interactive language %s devs %s", lang, devs); |
debug("keyboard-interactive language %s devs %s", lang, devs); |
#ifdef SKEY |
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/* XXX hardcoded, we should look at devs */ |
if (options.challenge_reponse_authentication) |
if (options.skey_authentication != 0) |
authenticated = auth2_challenge(authctxt, devs); |
authenticated = auth2_skey(authctxt); |
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#endif |
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xfree(lang); |
xfree(lang); |
xfree(devs); |
xfree(devs); |
return authenticated; |
return authenticated; |
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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 (!authctxt->valid) { |
if (!authctxt->valid) { |
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return 0; |
return 0; |
} |
} |
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"); |
log("bad pkalg %s", pkalg); /*XXX*/ |
/* 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); |
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xfree(pkblob); |
return 0; |
return 0; |
} |
} |
pkblob = packet_get_string(&blen); |
key = key_from_blob(pkblob, blen); |
key = dsa_key_from_blob(pkblob, blen); |
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if (key != NULL) { |
if (key != NULL) { |
if (have_sig) { |
if (have_sig) { |
sig = packet_get_string(&slen); |
sig = packet_get_string(&slen); |
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buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_cstring(&b, authctxt->user); |
buffer_put_cstring(&b, authctxt->user); |
buffer_put_cstring(&b, |
buffer_put_cstring(&b, |
datafellows & SSH_BUG_PUBKEYAUTH ? |
datafellows & SSH_BUG_PKSERVICE ? |
"ssh-userauth" : |
"ssh-userauth" : |
authctxt->service); |
authctxt->service); |
buffer_put_cstring(&b, "publickey"); |
if (datafellows & SSH_BUG_PKAUTH) { |
buffer_put_char(&b, have_sig); |
buffer_put_char(&b, have_sig); |
buffer_put_cstring(&b, KEX_DSS); |
} 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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} |
buffer_put_string(&b, pkblob, blen); |
buffer_put_string(&b, pkblob, blen); |
#ifdef DEBUG_DSS |
#ifdef DEBUG_PK |
buffer_dump(&b); |
buffer_dump(&b); |
#endif |
#endif |
/* test for correct signature */ |
/* test for correct signature */ |
if (user_dsa_key_allowed(authctxt->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); |
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* 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(authctxt->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; |
} |
} |
} |
} |
if (authenticated != 1) |
if (authenticated != 1) |
auth_clear_options(); |
auth_clear_options(); |
key_free(key); |
key_free(key); |
} |
} |
|
debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg); |
xfree(pkalg); |
xfree(pkalg); |
xfree(pkblob); |
xfree(pkblob); |
return authenticated; |
return authenticated; |
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authmethods_get(void) |
authmethods_get(void) |
{ |
{ |
Authmethod *method = NULL; |
Authmethod *method = NULL; |
unsigned int size = 0; |
u_int size = 0; |
char *list; |
char *list; |
|
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for (method = authmethods; method->name != NULL; method++) { |
for (method = authmethods; method->name != NULL; method++) { |
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|
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/* 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; |
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/* 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); |
|
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/* Fail quietly if file does not exist */ |
/* Fail quietly if file does not exist */ |
if (stat(file, &st) < 0) { |
if (stat(file, &st) < 0) { |
|
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key_type(key), pw->pw_name, file); |
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", |
|
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if (!*cp || *cp == '\n' || *cp == '#') |
if (!*cp || *cp == '\n' || *cp == '#') |
continue; |
continue; |
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bits = key_read(found, &cp); |
if (key_read(found, &cp) == -1) { |
if (bits == 0) { |
|
/* no key? check if there are options for this key */ |
/* no key? check if there are options for this key */ |
int quoted = 0; |
int quoted = 0; |
|
debug2("user_key_allowed: check options: '%s'", cp); |
options = cp; |
options = cp; |
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { |
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { |
if (*cp == '\\' && cp[1] == '"') |
if (*cp == '\\' && cp[1] == '"') |
|
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/* Skip remaining whitespace. */ |
/* Skip remaining whitespace. */ |
for (; *cp == ' ' || *cp == '\t'; cp++) |
for (; *cp == ' ' || *cp == '\t'; cp++) |
; |
; |
bits = key_read(found, &cp); |
if (key_read(found, &cp) == -1) { |
if (bits == 0) { |
debug2("user_key_allowed: advance: '%s'", cp); |
/* still no key? advance to next line*/ |
/* still no key? advance to next line*/ |
continue; |
continue; |
} |
} |
} |
} |
if (key_equal(found, key) && |
if (key_equal(found, key) && |
auth_parse_options(pw, options, linenum) == 1) { |
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); |
|
|
fclose(f); |
fclose(f); |
key_free(found); |
key_free(found); |
return found_key; |
return found_key; |
} |
|
|
|
struct passwd * |
|
pwcopy(struct passwd *pw) |
|
{ |
|
struct passwd *copy = xmalloc(sizeof(*copy)); |
|
memset(copy, 0, sizeof(*copy)); |
|
copy->pw_name = xstrdup(pw->pw_name); |
|
copy->pw_passwd = xstrdup(pw->pw_passwd); |
|
copy->pw_uid = pw->pw_uid; |
|
copy->pw_gid = pw->pw_gid; |
|
copy->pw_class = xstrdup(pw->pw_class); |
|
copy->pw_dir = xstrdup(pw->pw_dir); |
|
copy->pw_shell = xstrdup(pw->pw_shell); |
|
return copy; |
|
} |
} |