]> andersk Git - openssh.git/blobdiff - sshconnect2.c
- (bal) auth1.c minor resync while looking at the code.
[openssh.git] / sshconnect2.c
index 3e5ca7ad11961cc1e5eb2e617bb482cfe5856445..90b884a398d261f78aaa35c6358f9a5dfefbc6f7 100644 (file)
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.93 2002/01/13 17:57:37 markus Exp $");
-
-#include <openssl/bn.h>
-#include <openssl/md5.h>
-#include <openssl/dh.h>
-#include <openssl/hmac.h>
+RCSID("$OpenBSD: sshconnect2.c,v 1.115 2003/04/02 09:48:07 markus Exp $");
 
 #include "ssh.h"
 #include "ssh2.h"
 #include "xmalloc.h"
-#include "rsa.h"
 #include "buffer.h"
 #include "packet.h"
-#include "uidswap.h"
 #include "compat.h"
 #include "bufaux.h"
 #include "cipher.h"
 #include "kex.h"
 #include "myproposal.h"
-#include "key.h"
 #include "sshconnect.h"
 #include "authfile.h"
 #include "dh.h"
@@ -53,6 +45,8 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.93 2002/01/13 17:57:37 markus Exp $");
 #include "match.h"
 #include "dispatch.h"
 #include "canohost.h"
+#include "msg.h"
+#include "pathnames.h"
 
 /* import */
 extern char *client_version_string;
@@ -88,7 +82,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
        xxx_hostaddr = hostaddr;
 
        if (options.ciphers == (char *)-1) {
-               log("No valid ciphers for protocol version 2 given, using defaults.");
+               logit("No valid ciphers for protocol version 2 given, using defaults.");
                options.ciphers = NULL;
        }
        if (options.ciphers != NULL) {
@@ -101,10 +95,10 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
            compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
        if (options.compression) {
                myproposal[PROPOSAL_COMP_ALGS_CTOS] =
-               myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
+               myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
        } else {
                myproposal[PROPOSAL_COMP_ALGS_CTOS] =
-               myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+               myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
        }
        if (options.macs != NULL) {
                myproposal[PROPOSAL_MAC_ALGS_CTOS] =
@@ -114,8 +108,13 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
                myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
                    options.hostkeyalgorithms;
 
+       if (options.rekey_limit)
+               packet_set_rekey_limit(options.rekey_limit);
+
        /* start key exchange */
        kex = kex_setup(myproposal);
+       kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
+       kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
        kex->client_version_string=client_version_string;
        kex->server_version_string=server_version_string;
        kex->verify_host_key=&verify_host_key_callback;
@@ -134,7 +133,6 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
        packet_send();
        packet_write_wait();
 #endif
-       debug("done: ssh_kex2.");
 }
 
 /*
@@ -146,7 +144,7 @@ typedef struct Authmethod Authmethod;
 
 typedef int sign_cb_fn(
     Authctxt *authctxt, Key *key,
-    u_char **sigp, int *lenp, u_char *data, int datalen);
+    u_char **sigp, u_int *lenp, u_char *data, u_int datalen);
 
 struct Authctxt {
        const char *server_user;
@@ -162,8 +160,7 @@ struct Authctxt {
        int last_key_hint;
        AuthenticationConnection *agent;
        /* hostbased */
-       Key **keys;
-       int nkeys;
+       Sensitive *sensitive;
        /* kbd-interactive */
        int info_req_seen;
 };
@@ -180,6 +177,7 @@ void        input_userauth_banner(int, u_int32_t, void *);
 void   input_userauth_error(int, u_int32_t, void *);
 void   input_userauth_info_req(int, u_int32_t, void *);
 void   input_userauth_pk_ok(int, u_int32_t, void *);
+void   input_userauth_passwd_changereq(int, u_int32_t, void *);
 
 int    userauth_none(Authctxt *);
 int    userauth_pubkey(Authctxt *);
@@ -222,7 +220,7 @@ Authmethod authmethods[] = {
 
 void
 ssh_userauth2(const char *local_user, const char *server_user, char *host,
-    Key **keys, int nkeys)
+    Sensitive *sensitive)
 {
        Authctxt authctxt;
        int type;
@@ -230,24 +228,23 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
        if (options.challenge_response_authentication)
                options.kbd_interactive_authentication = 1;
 
-       debug("send SSH2_MSG_SERVICE_REQUEST");
        packet_start(SSH2_MSG_SERVICE_REQUEST);
        packet_put_cstring("ssh-userauth");
        packet_send();
+       debug("SSH2_MSG_SERVICE_REQUEST sent");
        packet_write_wait();
        type = packet_read();
-       if (type != SSH2_MSG_SERVICE_ACCEPT) {
-               fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type);
-       }
+       if (type != SSH2_MSG_SERVICE_ACCEPT)
+               fatal("Server denied authentication request: %d", type);
        if (packet_remaining() > 0) {
                char *reply = packet_get_string(NULL);
-               debug("service_accept: %s", reply);
+               debug2("service_accept: %s", reply);
                xfree(reply);
        } else {
-               debug("buggy server: service_accept w/o service");
+               debug2("buggy server: service_accept w/o service");
        }
        packet_check_eom();
-       debug("got SSH2_MSG_SERVICE_ACCEPT");
+       debug("SSH2_MSG_SERVICE_ACCEPT received");
 
        if (options.preferred_authentications == NULL)
                options.preferred_authentications = authmethods_get();
@@ -262,8 +259,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
        authctxt.success = 0;
        authctxt.method = authmethod_lookup("none");
        authctxt.authlist = NULL;
-       authctxt.keys = keys;
-       authctxt.nkeys = nkeys;
+       authctxt.sensitive = sensitive;
        authctxt.info_req_seen = 0;
        if (authctxt.method == NULL)
                fatal("ssh_userauth2: internal error: cannot send userauth none request");
@@ -280,7 +276,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
        if (authctxt.agent != NULL)
                ssh_close_authentication_connection(authctxt.agent);
 
-       debug("ssh-userauth2 successful: method %s", authctxt.method->name);
+       debug("Authentication succeeded (%s).", authctxt.method->name);
 }
 void
 userauth(Authctxt *authctxt, char *authlist)
@@ -306,12 +302,14 @@ userauth(Authctxt *authctxt, char *authlist)
                }
        }
 }
+
 void
 input_userauth_error(int type, u_int32_t seq, void *ctxt)
 {
        fatal("input_userauth_error: bad message during authentication: "
           "type %d", type);
 }
+
 void
 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
 {
@@ -323,6 +321,7 @@ input_userauth_banner(int type, u_int32_t seq, void *ctxt)
        xfree(msg);
        xfree(lang);
 }
+
 void
 input_userauth_success(int type, u_int32_t seq, void *ctxt)
 {
@@ -334,6 +333,7 @@ input_userauth_success(int type, u_int32_t seq, void *ctxt)
        clear_auth_state(authctxt);
        authctxt->success = 1;                  /* break out */
 }
+
 void
 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
 {
@@ -349,8 +349,8 @@ input_userauth_failure(int type, u_int32_t seq, void *ctxt)
        packet_check_eom();
 
        if (partial != 0)
-               log("Authenticated with partial success.");
-       debug("authentications that can continue: %s", authlist);
+               logit("Authenticated with partial success.");
+       debug("Authentications that can continue: %s", authlist);
 
        clear_auth_state(authctxt);
        userauth(authctxt, authlist);
@@ -361,8 +361,10 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
        Authctxt *authctxt = ctxt;
        Key *key = NULL;
        Buffer b;
-       int alen, blen, sent = 0;
-       char *pkalg, *pkblob, *fp;
+       int pktype, sent = 0;
+       u_int alen, blen;
+       char *pkalg, *fp;
+       u_char *pkblob;
 
        if (authctxt == NULL)
                fatal("input_userauth_pk_ok: no authentication context");
@@ -380,7 +382,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
        }
        packet_check_eom();
 
-       debug("input_userauth_pk_ok: pkalg %s blen %d lastkey %p hint %d",
+       debug("Server accepts key: pkalg %s blen %u lastkey %p hint %d",
            pkalg, blen, authctxt->last_key, authctxt->last_key_hint);
 
        do {
@@ -389,7 +391,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
                        debug("no last key or no sign cb");
                        break;
                }
-               if (key_type_from_name(pkalg) == KEY_UNSPEC) {
+               if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
                        debug("unknown pkalg %s", pkalg);
                        break;
                }
@@ -397,6 +399,12 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
                        debug("no key from blob. pkalg %s", pkalg);
                        break;
                }
+               if (key->type != pktype) {
+                       error("input_userauth_pk_ok: type mismatch "
+                           "for decoded key (received %d, expected %d)",
+                           key->type, pktype);
+                       break;
+               }
                fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
                debug2("input_userauth_pk_ok: fp %s", fp);
                xfree(fp);
@@ -417,7 +425,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
        clear_auth_state(authctxt);
        dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL);
 
-       /* try another method if we did not send a packet*/
+       /* try another method if we did not send a packet */
        if (sent == 0)
                userauth(authctxt, NULL);
 
@@ -439,7 +447,7 @@ int
 userauth_passwd(Authctxt *authctxt)
 {
        static int attempt = 0;
-       char prompt[80];
+       char prompt[150];
        char *password;
 
        if (attempt++ >= options.number_of_password_prompts)
@@ -461,13 +469,85 @@ userauth_passwd(Authctxt *authctxt)
        xfree(password);
        packet_add_padding(64);
        packet_send();
+
+       dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
+           &input_userauth_passwd_changereq);
+
        return 1;
 }
+/*
+ * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
+ */
+void
+input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
+{
+       Authctxt *authctxt = ctxt;
+       char *info, *lang, *password = NULL, *retype = NULL;
+       char prompt[150];
+
+       debug2("input_userauth_passwd_changereq");
+
+       if (authctxt == NULL)
+               fatal("input_userauth_passwd_changereq: "
+                   "no authentication context");
+
+       info = packet_get_string(NULL);
+       lang = packet_get_string(NULL);
+       if (strlen(info) > 0)
+               logit("%s", info);
+       xfree(info);
+       xfree(lang);
+       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(1);                     /* additional info */
+       snprintf(prompt, sizeof(prompt),
+           "Enter %.30s@%.128s's old password: ",
+           authctxt->server_user, authctxt->host);
+       password = read_passphrase(prompt, 0);
+       packet_put_cstring(password);
+       memset(password, 0, strlen(password));
+       xfree(password);
+       password = NULL;
+       while (password == NULL) {
+               snprintf(prompt, sizeof(prompt),
+                   "Enter %.30s@%.128s's new password: ",
+                   authctxt->server_user, authctxt->host);
+               password = read_passphrase(prompt, RP_ALLOW_EOF);
+               if (password == NULL) {
+                       /* bail out */
+                       return;
+               }
+               snprintf(prompt, sizeof(prompt),
+                   "Retype %.30s@%.128s's new password: ",
+                   authctxt->server_user, authctxt->host);
+               retype = read_passphrase(prompt, 0);
+               if (strcmp(password, retype) != 0) {
+                       memset(password, 0, strlen(password));
+                       xfree(password);
+                       logit("Mismatch; try again, EOF to quit.");
+                       password = NULL;
+               }
+               memset(retype, 0, strlen(retype));
+               xfree(retype);
+       }
+       packet_put_cstring(password);
+       memset(password, 0, strlen(password));
+       xfree(password);
+       packet_add_padding(64);
+       packet_send();
+
+       dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
+           &input_userauth_passwd_changereq);
+}
 
 static void
 clear_auth_state(Authctxt *authctxt)
 {
        /* XXX clear authentication state */
+       dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL);
+
        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);
@@ -482,7 +562,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
 {
        Buffer b;
        u_char *blob, *signature;
-       int bloblen, slen;
+       u_int bloblen, slen;
        int skip = 0;
        int ret = -1;
        int have_sig = 1;
@@ -567,7 +647,7 @@ send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
     int hint)
 {
        u_char *blob;
-       int bloblen, have_sig = 0;
+       u_int bloblen, have_sig = 0;
 
        debug3("send_pubkey_test");
 
@@ -634,8 +714,8 @@ load_identity_file(char *filename)
 }
 
 static int
-identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
-    u_char *data, int datalen)
+identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
+    u_char *data, u_int datalen)
 {
        Key *private;
        int idx, ret;
@@ -657,15 +737,15 @@ identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
 }
 
 static int
-agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
-    u_char *data, int datalen)
+agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
+    u_char *data, u_int datalen)
 {
        return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
 }
 
 static int
-key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp,
-    u_char *data, int datalen)
+key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
+    u_char *data, u_int datalen)
 {
        return key_sign(key, sigp, lenp, data, datalen);
 }
@@ -687,7 +767,7 @@ userauth_pubkey_agent(Authctxt *authctxt)
        if (k == NULL) {
                debug2("userauth_pubkey_agent: no more keys");
        } else {
-               debug("userauth_pubkey_agent: testing agent key %s", comment);
+               debug("Offering agent key: %s", comment);
                xfree(comment);
                ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1);
                if (ret == 0)
@@ -715,7 +795,7 @@ userauth_pubkey(Authctxt *authctxt)
                key = options.identity_keys[idx];
                filename = options.identity_files[idx];
                if (key == NULL) {
-                       debug("try privkey: %s", filename);
+                       debug("Trying private key: %s", filename);
                        key = load_identity_file(filename);
                        if (key != NULL) {
                                sent = sign_and_send_pubkey(authctxt, key,
@@ -723,7 +803,7 @@ userauth_pubkey(Authctxt *authctxt)
                                key_free(key);
                        }
                } else if (key->type != KEY_RSA1) {
-                       debug("try pubkey: %s", filename);
+                       debug("Offering public key: %s", filename);
                        sent = send_pubkey_test(authctxt, key,
                            identity_sign_cb, idx);
                }
@@ -785,9 +865,9 @@ input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
        inst = packet_get_string(NULL);
        lang = packet_get_string(NULL);
        if (strlen(name) > 0)
-               log("%s", name);
+               logit("%s", name);
        if (strlen(inst) > 0)
-               log("%s", inst);
+               logit("%s", inst);
        xfree(name);
        xfree(inst);
        xfree(lang);
@@ -820,14 +900,86 @@ input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
        packet_send();
 }
 
-/*
- * this will be move to an external program (ssh-keysign) ASAP. ssh-keysign
- * will be setuid-root and the sbit can be removed from /usr/bin/ssh.
- */
+static int
+ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
+    u_char *data, u_int datalen)
+{
+       Buffer b;
+       struct stat st;
+       pid_t pid;
+       int to[2], from[2], status, version = 2;
+
+       debug2("ssh_keysign called");
+
+       if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
+               error("ssh_keysign: no installed: %s", strerror(errno));
+               return -1;
+       }
+       if (fflush(stdout) != 0)
+               error("ssh_keysign: fflush: %s", strerror(errno));
+       if (pipe(to) < 0) {
+               error("ssh_keysign: pipe: %s", strerror(errno));
+               return -1;
+       }
+       if (pipe(from) < 0) {
+               error("ssh_keysign: pipe: %s", strerror(errno));
+               return -1;
+       }
+       if ((pid = fork()) < 0) {
+               error("ssh_keysign: fork: %s", strerror(errno));
+               return -1;
+       }
+       if (pid == 0) {
+               seteuid(getuid());
+               setuid(getuid());
+               close(from[0]);
+               if (dup2(from[1], STDOUT_FILENO) < 0)
+                       fatal("ssh_keysign: dup2: %s", strerror(errno));
+               close(to[1]);
+               if (dup2(to[0], STDIN_FILENO) < 0)
+                       fatal("ssh_keysign: dup2: %s", strerror(errno));
+               close(from[1]);
+               close(to[0]);
+               execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
+               fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
+                   strerror(errno));
+       }
+       close(from[1]);
+       close(to[0]);
+
+       buffer_init(&b);
+       buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
+       buffer_put_string(&b, data, datalen);
+       ssh_msg_send(to[1], version, &b);
+
+       if (ssh_msg_recv(from[0], &b) < 0) {
+               error("ssh_keysign: no reply");
+               buffer_clear(&b);
+               return -1;
+       }
+       close(from[0]);
+       close(to[1]);
+
+       while (waitpid(pid, &status, 0) < 0)
+               if (errno != EINTR)
+                       break;
+
+       if (buffer_get_char(&b) != version) {
+               error("ssh_keysign: bad version");
+               buffer_clear(&b);
+               return -1;
+       }
+       *sigp = buffer_get_string(&b, lenp);
+       buffer_clear(&b);
+
+       return 0;
+}
+
 int
 userauth_hostbased(Authctxt *authctxt)
 {
        Key *private = NULL;
+       Sensitive *sensitive = authctxt->sensitive;
        Buffer b;
        u_char *signature, *blob;
        char *chost, *pkalg, *p;
@@ -836,17 +988,17 @@ userauth_hostbased(Authctxt *authctxt)
        int ok, i, len, found = 0;
 
        /* check for a useful key */
-       for (i = 0; i < authctxt->nkeys; i++) {
-               private = authctxt->keys[i];
+       for (i = 0; i < sensitive->nkeys; i++) {
+               private = sensitive->keys[i];
                if (private && private->type != KEY_RSA1) {
                        found = 1;
                        /* we take and free the key */
-                       authctxt->keys[i] = NULL;
+                       sensitive->keys[i] = NULL;
                        break;
                }
        }
        if (!found) {
-               debug("userauth_hostbased: no more client hostkeys");
+               debug("No more client hostkeys for hostbased authentication.");
                return 0;
        }
        if (key_to_blob(private, &blob, &blen) == 0) {
@@ -865,6 +1017,7 @@ userauth_hostbased(Authctxt *authctxt)
        strlcpy(chost, p, len);
        strlcat(chost, ".", len);
        debug2("userauth_hostbased: chost %s", chost);
+       xfree(p);
 
        service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
            authctxt->service;
@@ -883,7 +1036,12 @@ userauth_hostbased(Authctxt *authctxt)
 #ifdef DEBUG_PK
        buffer_dump(&b);
 #endif
-       ok = key_sign(private, &signature, &slen, buffer_ptr(&b), buffer_len(&b));
+       if (sensitive->external_keysign)
+               ok = ssh_keysign(private, &signature, &slen,
+                   buffer_ptr(&b), buffer_len(&b));
+       else
+               ok = key_sign(private, &signature, &slen,
+                   buffer_ptr(&b), buffer_len(&b));
        key_free(private);
        buffer_free(&b);
        if (ok != 0) {
@@ -946,6 +1104,7 @@ authmethod_lookup(const char *name)
 static Authmethod *current = NULL;
 static char *supported = NULL;
 static char *preferred = NULL;
+
 /*
  * Given the authentication method list sent by the server, return the
  * next method we should try.  If the server initially sends a nil list,
@@ -954,9 +1113,8 @@ static char *preferred = NULL;
 static Authmethod *
 authmethod_get(char *authlist)
 {
-
        char *name = NULL;
-       int next;
+       u_int next;
 
        /* Use a suitable default if we're passed a nil list.  */
        if (authlist == NULL || strlen(authlist) == 0)
@@ -975,7 +1133,7 @@ authmethod_get(char *authlist)
 
        for (;;) {
                if ((name = match_list(preferred, supported, &next)) == NULL) {
-                       debug("no more auth methods to try");
+                       debug("No more authentication methods to try.");
                        current = NULL;
                        return NULL;
                }
@@ -985,7 +1143,7 @@ authmethod_get(char *authlist)
                if ((current = authmethod_lookup(name)) != NULL &&
                    authmethod_is_enabled(current)) {
                        debug3("authmethod_is_enabled %s", name);
-                       debug("next auth method to try is %s", name);
+                       debug("Next authentication method: %s", name);
                        return current;
                }
        }
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