]> andersk Git - openssh.git/blobdiff - sshconnect2.c
- markus@cvs.openbsd.org 2001/03/08 21:42:33
[openssh.git] / sshconnect2.c
index 0baecf0a55d63e368c1d7c6d6724d9b19688b164..81e1aef930725436da7682971c43efd7f1ecb09a 100644 (file)
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.50 2001/03/05 17:17:21 markus Exp $");
+RCSID("$OpenBSD: sshconnect2.c,v 1.51 2001/03/08 21:42:33 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/md5.h>
@@ -467,6 +467,10 @@ struct Authctxt {
        AuthenticationConnection *agent;
        Authmethod *method;
        int success;
+       char *authlist;
+       Key *last_key;
+       sign_cb_fn *last_key_sign;
+       int last_key_hint;
 };
 struct Authmethod {
        char    *name;          /* string to compare against server's list */
@@ -480,12 +484,20 @@ void      input_userauth_failure(int type, int plen, void *ctxt);
 void   input_userauth_banner(int type, int plen, void *ctxt);
 void   input_userauth_error(int type, int plen, void *ctxt);
 void   input_userauth_info_req(int type, int plen, void *ctxt);
+void   input_userauth_pk_ok(int type, int plen, void *ctxt);
 
 int    userauth_none(Authctxt *authctxt);
 int    userauth_pubkey(Authctxt *authctxt);
 int    userauth_passwd(Authctxt *authctxt);
 int    userauth_kbdint(Authctxt *authctxt);
 
+void   userauth(Authctxt *authctxt, char *authlist);
+
+int
+sign_and_send_pubkey(Authctxt *authctxt, Key *k,
+    sign_cb_fn *sign_callback);
+void   clear_auth_state(Authctxt *authctxt);
+
 void   authmethod_clear(void);
 Authmethod *authmethod_get(char *authlist);
 Authmethod *authmethod_lookup(const char *name);
@@ -546,6 +558,7 @@ ssh_userauth2(const char *server_user, char *host)
        authctxt.service = "ssh-connection";            /* service name */
        authctxt.success = 0;
        authctxt.method = authmethod_lookup("none");
+       authctxt.authlist = NULL;
        if (authctxt.method == NULL)
                fatal("ssh_userauth2: internal error: cannot send userauth none request");
        authmethod_clear();
@@ -565,6 +578,30 @@ ssh_userauth2(const char *server_user, char *host)
        debug("ssh-userauth2 successful: method %s", authctxt.method->name);
 }
 void
+userauth(Authctxt *authctxt, char *authlist)
+{
+       if (authlist == NULL) {
+               authlist = authctxt->authlist;
+       } else {
+               if (authctxt->authlist)
+                       xfree(authctxt->authlist);
+               authctxt->authlist = authlist;
+       }
+       for (;;) {
+               Authmethod *method = authmethod_get(authlist);
+               if (method == NULL)
+                       fatal("Permission denied (%s).", authlist);
+               authctxt->method = method;
+               if (method->userauth(authctxt) != 0) {
+                       debug2("we sent a %s packet, wait for reply", method->name);
+                       break;
+               } else {
+                       debug2("we did not send a packet, disable method");
+                       method->enabled = NULL;
+               }
+       }
+}
+void
 input_userauth_error(int type, int plen, void *ctxt)
 {
        fatal("input_userauth_error: bad message during authentication: "
@@ -587,12 +624,14 @@ input_userauth_success(int type, int plen, void *ctxt)
        Authctxt *authctxt = ctxt;
        if (authctxt == NULL)
                fatal("input_userauth_success: no authentication context");
+       if (authctxt->authlist)
+               xfree(authctxt->authlist);
+       clear_auth_state(authctxt);
        authctxt->success = 1;                  /* break out */
 }
 void
 input_userauth_failure(int type, int plen, void *ctxt)
 {
-       Authmethod *method = NULL;
        Authctxt *authctxt = ctxt;
        char *authlist = NULL;
        int partial;
@@ -608,20 +647,74 @@ input_userauth_failure(int type, int plen, void *ctxt)
                log("Authenticated with partial success.");
        debug("authentications that can continue: %s", authlist);
 
-       for (;;) {
-               method = authmethod_get(authlist);
-               if (method == NULL)
-                       fatal("Permission denied (%s).", authlist);
-               authctxt->method = method;
-               if (method->userauth(authctxt) != 0) {
-                       debug2("we sent a %s packet, wait for reply", method->name);
+       clear_auth_state(authctxt);
+       userauth(authctxt, authlist);
+}
+void
+input_userauth_pk_ok(int type, int plen, void *ctxt)
+{
+       Authctxt *authctxt = ctxt;
+       Key *key = NULL;
+       Buffer b;
+       int alen, blen, pktype, sent = 0;
+       char *pkalg, *pkblob;
+
+       if (authctxt == NULL)
+               fatal("input_userauth_pk_ok: no authentication context");
+       if (datafellows & SSH_BUG_PKOK) {
+               /* this is similar to SSH_BUG_PKAUTH */
+               debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
+               pkblob = packet_get_string(&blen);
+               buffer_init(&b);
+               buffer_append(&b, pkblob, blen);
+               pkalg = buffer_get_string(&b, &alen);
+               buffer_free(&b);
+       } else {
+               pkalg = packet_get_string(&alen);
+               pkblob = packet_get_string(&blen);
+       }
+       packet_done();
+
+       debug("input_userauth_pk_ok: pkalg %s blen %d lastkey %p hint %d",
+           pkalg, blen, authctxt->last_key, authctxt->last_key_hint);
+
+       do {
+               if (authctxt->last_key == NULL ||
+                   authctxt->last_key_sign == NULL) {
+                       debug("no last key or no sign cb");
                        break;
-               } else {
-                       debug2("we did not send a packet, disable method");
-                       method->enabled = NULL;
                }
-       }
-       xfree(authlist);
+               debug2("last_key %s", key_fingerprint(authctxt->last_key));
+               if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
+                       debug("unknown pkalg %s", pkalg);
+                       break;
+               }
+               if ((key = key_from_blob(pkblob, blen)) == NULL) {
+                       debug("no key from blob. pkalg %s", pkalg);
+                       break;
+               }
+               debug2("input_userauth_pk_ok: fp %s", key_fingerprint(key));
+               if (!key_equal(key, authctxt->last_key)) {
+                       debug("key != last_key");
+                       break;
+               }
+               sent = sign_and_send_pubkey(authctxt, key,
+                  authctxt->last_key_sign);
+       } while(0);
+
+       if (key != NULL)
+               key_free(key);
+       xfree(pkalg);
+       xfree(pkblob);
+
+       /* unregister */
+       clear_auth_state(authctxt);
+       dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL);
+
+       /* try another method if we did not send a packet*/
+       if (sent == 0)
+               userauth(authctxt, NULL);
+
 }
 
 int
@@ -633,7 +726,6 @@ userauth_none(Authctxt *authctxt)
        packet_put_cstring(authctxt->service);
        packet_put_cstring(authctxt->method->name);
        packet_send();
-       packet_write_wait();
        return 1;
 }
 
@@ -663,10 +755,22 @@ userauth_passwd(Authctxt *authctxt)
        xfree(password);
        packet_inject_ignore(64);
        packet_send();
-       packet_write_wait();
        return 1;
 }
 
+void
+clear_auth_state(Authctxt *authctxt)
+{
+       /* XXX clear authentication state */
+       if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) {
+               debug3("clear_auth_state: key_free %p", authctxt->last_key);
+               key_free(authctxt->last_key);
+       }
+       authctxt->last_key = NULL;
+       authctxt->last_key_hint = -2;
+       authctxt->last_key_sign = NULL;
+}
+
 int
 sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
 {
@@ -678,6 +782,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
        int have_sig = 1;
 
        debug3("sign_and_send_pubkey");
+
        if (key_to_blob(k, &blob, &bloblen) == 0) {
                /* we cannot handle this key */
                debug3("sign_and_send_pubkey: cannot handle key");
@@ -708,7 +813,8 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
        buffer_put_string(&b, blob, bloblen);
 
        /* generate signature */
-       ret = (*sign_callback)(authctxt, k, &signature, &slen, buffer_ptr(&b), buffer_len(&b));
+       ret = (*sign_callback)(authctxt, k, &signature, &slen,
+           buffer_ptr(&b), buffer_len(&b));
        if (ret == -1) {
                xfree(blob);
                buffer_free(&b);
@@ -720,6 +826,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
        if (datafellows & SSH_BUG_PKSERVICE) {
                buffer_clear(&b);
                buffer_append(&b, session_id2, session_id2_len);
+               skip = session_id2_len;
                buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
                buffer_put_cstring(&b, authctxt->server_user);
                buffer_put_cstring(&b, authctxt->service);
@@ -730,6 +837,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
                buffer_put_string(&b, blob, bloblen);
        }
        xfree(blob);
+
        /* append signature */
        buffer_put_string(&b, signature, slen);
        xfree(signature);
@@ -743,76 +851,113 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
        packet_start(SSH2_MSG_USERAUTH_REQUEST);
        packet_put_raw(buffer_ptr(&b), buffer_len(&b));
        buffer_free(&b);
-
-       /* send */
        packet_send();
-       packet_write_wait();
 
        return 1;
 }
 
-/* sign callback */
-int key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
-    u_char *data, int datalen)
-{
-       return key_sign(key, sigp, lenp, data, datalen);
-}
-
 int
-userauth_pubkey_identity(Authctxt *authctxt, char *filename)
+send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
+    int hint)
 {
-       Key *k;
-       int i, ret, try_next, success = 0;
-       struct stat st;
-       char *passphrase;
-       char prompt[300];
+       u_char *blob;
+       int bloblen, have_sig = 0;
 
-       if (stat(filename, &st) != 0) {
-               debug("key does not exist: %s", filename);
+       debug3("send_pubkey_test");
+
+       if (key_to_blob(k, &blob, &bloblen) == 0) {
+               /* we cannot handle this key */
+               debug3("send_pubkey_test: cannot handle key");
                return 0;
        }
-       debug("try pubkey: %s", filename);
+       /* register callback for USERAUTH_PK_OK message */
+       authctxt->last_key_sign = sign_callback;
+       authctxt->last_key_hint = hint;
+       authctxt->last_key = k;
+       dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
 
-       k = key_new(KEY_UNSPEC);
-       if (!load_private_key(filename, "", k, NULL)) {
+       packet_start(SSH2_MSG_USERAUTH_REQUEST);
+       packet_put_cstring(authctxt->server_user);
+       packet_put_cstring(authctxt->service);
+       packet_put_cstring(authctxt->method->name);
+       packet_put_char(have_sig);
+       if (!(datafellows & SSH_BUG_PKAUTH))
+               packet_put_cstring(key_ssh_name(k));
+       packet_put_string(blob, bloblen);
+       xfree(blob);
+       packet_send();
+       return 1;
+}
+
+Key *
+load_identity_file(char *filename)
+{
+       Key *private;
+       char prompt[300], *passphrase;
+       int success = 0, quit, i;
+
+       private = key_new(KEY_UNSPEC);
+       if (!load_private_key(filename, "", private, NULL)) {
                if (options.batch_mode) {
-                       key_free(k);
-                       return 0;
+                       key_free(private);
+                       return NULL;
                }
                snprintf(prompt, sizeof prompt,
                     "Enter passphrase for key '%.100s': ", filename);
                for (i = 0; i < options.number_of_password_prompts; i++) {
                        passphrase = read_passphrase(prompt, 0);
                        if (strcmp(passphrase, "") != 0) {
-                               success = load_private_key(filename, passphrase, k, NULL);
-                               try_next = 0;
+                               success = load_private_key(filename,
+                                   passphrase, private, NULL);
+                               quit = 0;
                        } else {
                                debug2("no passphrase given, try next key");
-                               try_next = 1;
+                               quit = 1;
                        }
                        memset(passphrase, 0, strlen(passphrase));
                        xfree(passphrase);
-                       if (success || try_next)
+                       if (success || quit)
                                break;
                        debug2("bad passphrase given, try again...");
                }
                if (!success) {
-                       key_free(k);
-                       return 0;
+                       key_free(private);
+                       return NULL;
                }
        }
-       ret = sign_and_send_pubkey(authctxt, k, key_sign_cb);
-       key_free(k);
+       return private;
+}
+
+int
+identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
+    u_char *data, int datalen)
+{
+       Key *private;
+       int idx, ret;
+
+       idx = authctxt->last_key_hint;
+       if (idx < 0)
+               return -1;
+       private = load_identity_file(options.identity_files[idx]);
+       if (private == NULL)
+               return -1;
+       ret = key_sign(private, sigp, lenp, data, datalen);
+       key_free(private);
        return ret;
 }
 
-/* sign callback */
 int agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
     u_char *data, int datalen)
 {
        return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
 }
 
+int key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
+    u_char *data, int datalen)
+{
+        return key_sign(key, sigp, lenp, data, datalen);
+}
+
 int
 userauth_pubkey_agent(Authctxt *authctxt)
 {
@@ -830,10 +975,11 @@ userauth_pubkey_agent(Authctxt *authctxt)
        if (k == NULL) {
                debug2("userauth_pubkey_agent: no more keys");
        } else {
-               debug("userauth_pubkey_agent: trying agent key %s", comment);
+               debug("userauth_pubkey_agent: testing agent key %s", comment);
                xfree(comment);
-               ret = sign_and_send_pubkey(authctxt, k, agent_sign_cb);
-               key_free(k);
+               ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1);
+               if (ret == 0)
+                       key_free(k);
        }
        if (ret == 0)
                debug2("userauth_pubkey_agent: no message sent");
@@ -845,6 +991,8 @@ userauth_pubkey(Authctxt *authctxt)
 {
        static int idx = 0;
        int sent = 0;
+       Key *key;
+       char *filename;
 
        if (authctxt->agent != NULL) {
                do {
@@ -852,9 +1000,21 @@ userauth_pubkey(Authctxt *authctxt)
                } while(!sent && authctxt->agent->howmany > 0);
        }
        while (!sent && idx < options.num_identity_files) {
-               if (options.identity_files_type[idx] != KEY_RSA1)
-                       sent = userauth_pubkey_identity(authctxt,
-                           options.identity_files[idx]);
+               key = options.identity_keys[idx];
+               filename = options.identity_files[idx];
+               if (key == NULL) {
+                       debug("try privkey: %s", filename);
+                       key = load_identity_file(filename);
+                       if (key != NULL) {
+                               sent = sign_and_send_pubkey(authctxt, key,
+                                   key_sign_cb);
+                               key_free(key);
+                       }
+               } else if (key->type != KEY_RSA1) {
+                       debug("try pubkey: %s", filename);
+                       sent = send_pubkey_test(authctxt, key,
+                           identity_sign_cb, idx);
+               }
                idx++;
        }
        return sent;
@@ -880,7 +1040,6 @@ userauth_kbdint(Authctxt *authctxt)
        packet_put_cstring(options.kbd_interactive_devices ?
            options.kbd_interactive_devices : "");
        packet_send();
-       packet_write_wait();
 
        dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
        return 1;
@@ -938,7 +1097,6 @@ input_userauth_info_req(int type, int plen, void *ctxt)
 
        packet_inject_ignore(64);
        packet_send();
-       packet_write_wait();
 }
 
 /* find auth method */
This page took 0.129505 seconds and 4 git commands to generate.