===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/Attic/auth1.c,v
retrieving revision 1.6
retrieving revision 1.6.2.7
diff -u -r1.6 -r1.6.2.7
--- src/usr.bin/ssh/Attic/auth1.c	2000/10/11 20:27:23	1.6
+++ src/usr.bin/ssh/Attic/auth1.c	2002/03/08 17:04:41	1.6.2.7
@@ -10,27 +10,30 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth1.c,v 1.6 2000/10/11 20:27:23 markus Exp $");
+RCSID("$OpenBSD: auth1.c,v 1.6.2.7 2002/03/08 17:04:41 brad Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
-#include "ssh.h"
+#include "ssh1.h"
 #include "packet.h"
 #include "buffer.h"
 #include "mpaux.h"
+#include "log.h"
 #include "servconf.h"
 #include "compat.h"
 #include "auth.h"
+#include "channels.h"
 #include "session.h"
+#include "misc.h"
+#include "uidswap.h"
 
 /* import */
 extern ServerOptions options;
-extern char *forced_command;
 
 /*
  * convert ssh auth msg type into description
  */
-char *
+static char *
 get_authname(int type)
 {
 	static char buf[1024];
@@ -43,115 +46,122 @@
 		return "rhosts-rsa";
 	case SSH_CMSG_AUTH_RHOSTS:
 		return "rhosts";
-#ifdef KRB4
+	case SSH_CMSG_AUTH_TIS:
+	case SSH_CMSG_AUTH_TIS_RESPONSE:
+		return "challenge-response";
+#if defined(KRB4) || defined(KRB5)
 	case SSH_CMSG_AUTH_KERBEROS:
 		return "kerberos";
 #endif
-#ifdef SKEY
-	case SSH_CMSG_AUTH_TIS_RESPONSE:
-		return "s/key";
-#endif
 	}
 	snprintf(buf, sizeof buf, "bad-auth-msg-%d", type);
 	return buf;
 }
 
 /*
- * read packets and try to authenticate local user 'luser'.
- * return if authentication is successfull. not that pw == NULL
- * if the user does not exists or is not allowed to login.
- * each auth method has to 'fake' authentication for nonexisting
- * users.
+ * read packets, try to authenticate the user and
+ * return only if authentication is successful
  */
-void
-do_authloop(struct passwd * pw, char *luser)
+static void
+do_authloop(Authctxt *authctxt)
 {
 	int authenticated = 0;
-	int attempt = 0;
-	unsigned int bits;
-	RSA *client_host_key;
+	u_int bits;
+	Key *client_host_key;
 	BIGNUM *n;
 	char *client_user, *password;
-	char user[1024];
-	unsigned int dlen;
-	int plen, nlen, elen;
-	unsigned int ulen;
+	char info[1024];
+	u_int dlen;
+	u_int ulen;
 	int type = 0;
-	void (*authlog) (const char *fmt,...) = verbose;
+	struct passwd *pw = authctxt->pw;
 
+	debug("Attempting authentication for %s%.100s.",
+	    authctxt->valid ? "" : "illegal user ", authctxt->user);
+
+	/* If the user has no password, accept authentication immediately. */
+	if (options.password_authentication &&
+#if defined(KRB4) || defined(KRB5)
+	    (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
+#endif
+	    auth_password(authctxt, "")) {
+		auth_log(authctxt, 1, "without authentication", "");
+		return;
+	}
+
 	/* Indicate that authentication is needed. */
 	packet_start(SSH_SMSG_FAILURE);
 	packet_send();
 	packet_write_wait();
 
-	for (attempt = 1;; attempt++) {
+	for (;;) {
 		/* default to fail */
 		authenticated = 0;
 
-		strlcpy(user, "", sizeof user);
+		info[0] = '\0';
 
 		/* Get a packet from the client. */
-		type = packet_read(&plen);
+		type = packet_read();
 
 		/* Process the packet. */
 		switch (type) {
-#ifdef AFS
-		case SSH_CMSG_HAVE_KERBEROS_TGT:
-			if (!options.kerberos_tgt_passing) {
-				verbose("Kerberos tgt passing disabled.");
-				break;
-			} else {
-				/* Accept Kerberos tgt. */
-				char *tgt = packet_get_string(&dlen);
-				packet_integrity_check(plen, 4 + dlen, type);
-				if (!auth_kerberos_tgt(pw, tgt))
-					verbose("Kerberos tgt REFUSED for %.100s", luser);
-				xfree(tgt);
-			}
-			continue;
 
-		case SSH_CMSG_HAVE_AFS_TOKEN:
-			if (!options.afs_token_passing || !k_hasafs()) {
-				verbose("AFS token passing disabled.");
-				break;
-			} else {
-				/* Accept AFS token. */
-				char *token_string = packet_get_string(&dlen);
-				packet_integrity_check(plen, 4 + dlen, type);
-				if (!auth_afs_token(pw, token_string))
-					verbose("AFS token REFUSED for %.100s", luser);
-				xfree(token_string);
-			}
-			continue;
-#endif /* AFS */
-#ifdef KRB4
+#if defined(KRB4) || defined(KRB5)
 		case SSH_CMSG_AUTH_KERBEROS:
 			if (!options.kerberos_authentication) {
-				/* packet_get_all(); */
 				verbose("Kerberos authentication disabled.");
-				break;
 			} else {
-				/* Try Kerberos v4 authentication. */
-				KTEXT_ST auth;
-				char *tkt_user = NULL;
-				char *kdata = packet_get_string((unsigned int *) &auth.length);
-				packet_integrity_check(plen, 4 + auth.length, type);
+				char *kdata = packet_get_string(&dlen);
+				packet_check_eom();
 
-				if (auth.length < MAX_KTXT_LEN)
-					memcpy(auth.dat, kdata, auth.length);
-				xfree(kdata);
+				if (kdata[0] == 4) { /* KRB_PROT_VERSION */
+#ifdef KRB4
+					KTEXT_ST tkt;
 
-				if (pw != NULL) {
-					authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user);
-					if (authenticated) {
-						snprintf(user, sizeof user, " tktuser %s", tkt_user);
-						xfree(tkt_user);
+					tkt.length = dlen;
+					if (tkt.length < MAX_KTXT_LEN)
+						memcpy(tkt.dat, kdata, tkt.length);
+
+					if (auth_krb4(authctxt, &tkt, &client_user)) {
+						authenticated = 1;
+						snprintf(info, sizeof(info),
+						    " tktuser %.100s",
+						    client_user);
+						xfree(client_user);
 					}
+#endif /* KRB4 */
+				} else {
+#ifdef KRB5
+					krb5_data tkt;
+					tkt.length = dlen;
+					tkt.data = kdata;
+
+					if (auth_krb5(authctxt, &tkt, &client_user)) {
+						authenticated = 1;
+						snprintf(info, sizeof(info),
+						    " tktuser %.100s",
+						    client_user);
+						xfree(client_user);
+					}
+#endif /* KRB5 */
 				}
+				xfree(kdata);
 			}
 			break;
-#endif /* KRB4 */
+#endif /* KRB4 || KRB5 */
 
+#if defined(AFS) || defined(KRB5)
+			/* XXX - punt on backward compatibility here. */
+		case SSH_CMSG_HAVE_KERBEROS_TGT:
+			packet_send_debug("Kerberos TGT passing disabled before authentication.");
+			break;
+#ifdef AFS
+		case SSH_CMSG_HAVE_AFS_TOKEN:
+			packet_send_debug("AFS token passing disabled before authentication.");
+			break;
+#endif /* AFS */
+#endif /* AFS || KRB5 */
+
 		case SSH_CMSG_AUTH_RHOSTS:
 			if (!options.rhosts_authentication) {
 				verbose("Rhosts authentication disabled.");
@@ -164,12 +174,12 @@
 			 * IP-spoofing on a local network.)
 			 */
 			client_user = packet_get_string(&ulen);
-			packet_integrity_check(plen, 4 + ulen, type);
+			packet_check_eom();
 
 			/* Try to authenticate using /etc/hosts.equiv and .rhosts. */
 			authenticated = auth_rhosts(pw, client_user);
 
-			snprintf(user, sizeof user, " ruser %s", client_user);
+			snprintf(info, sizeof info, " ruser %.100s", client_user);
 			xfree(client_user);
 			break;
 
@@ -186,26 +196,22 @@
 			client_user = packet_get_string(&ulen);
 
 			/* Get the client host key. */
-			client_host_key = RSA_new();
-			if (client_host_key == NULL)
-				fatal("RSA_new failed");
-			client_host_key->e = BN_new();
-			client_host_key->n = BN_new();
-			if (client_host_key->e == NULL || client_host_key->n == NULL)
-				fatal("BN_new failed");
+			client_host_key = key_new(KEY_RSA1);
 			bits = packet_get_int();
-			packet_get_bignum(client_host_key->e, &elen);
-			packet_get_bignum(client_host_key->n, &nlen);
+			packet_get_bignum(client_host_key->rsa->e);
+			packet_get_bignum(client_host_key->rsa->n);
 
-			if (bits != BN_num_bits(client_host_key->n))
+			if (bits != BN_num_bits(client_host_key->rsa->n))
 				verbose("Warning: keysize mismatch for client_host_key: "
-				    "actual %d, announced %d", BN_num_bits(client_host_key->n), bits);
-			packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type);
+				    "actual %d, announced %d",
+				     BN_num_bits(client_host_key->rsa->n), bits);
+			packet_check_eom();
 
-			authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
-			RSA_free(client_host_key);
+			authenticated = auth_rhosts_rsa(pw, client_user,
+			    client_host_key);
+			key_free(client_host_key);
 
-			snprintf(user, sizeof user, " ruser %s", client_user);
+			snprintf(info, sizeof info, " ruser %.100s", client_user);
 			xfree(client_user);
 			break;
 
@@ -215,9 +221,10 @@
 				break;
 			}
 			/* RSA authentication requested. */
-			n = BN_new();
-			packet_get_bignum(n, &nlen);
-			packet_integrity_check(plen, nlen, type);
+			if ((n = BN_new()) == NULL)
+				fatal("do_authloop: BN_new failed");
+			packet_get_bignum(n);
+			packet_check_eom();
 			authenticated = auth_rsa(pw, n);
 			BN_clear_free(n);
 			break;
@@ -233,31 +240,24 @@
 			 * not visible to an outside observer.
 			 */
 			password = packet_get_string(&dlen);
-			packet_integrity_check(plen, 4 + dlen, type);
+			packet_check_eom();
 
 			/* Try authentication with the password. */
-			authenticated = auth_password(pw, password);
+			authenticated = auth_password(authctxt, password);
 
 			memset(password, 0, strlen(password));
 			xfree(password);
 			break;
 
-#ifdef SKEY
 		case SSH_CMSG_AUTH_TIS:
 			debug("rcvd SSH_CMSG_AUTH_TIS");
-			if (options.skey_authentication == 1) {
-				char *skeyinfo = NULL;
-				if (pw != NULL)
-					skey_keyinfo(pw->pw_name);
-				if (skeyinfo == NULL) {
-					debug("generating fake skeyinfo for %.100s.", luser);
-					skeyinfo = skey_fake_keyinfo(luser);
-				}
-				if (skeyinfo != NULL) {
-					/* we send our s/key- in tis-challenge messages */
-					debug("sending challenge '%s'", skeyinfo);
+			if (options.challenge_response_authentication == 1) {
+				char *challenge = get_challenge(authctxt);
+				if (challenge != NULL) {
+					debug("sending challenge '%s'", challenge);
 					packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
-					packet_put_cstring(skeyinfo);
+					packet_put_cstring(challenge);
+					xfree(challenge);
 					packet_send();
 					packet_write_wait();
 					continue;
@@ -266,22 +266,15 @@
 			break;
 		case SSH_CMSG_AUTH_TIS_RESPONSE:
 			debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
-			if (options.skey_authentication == 1) {
+			if (options.challenge_response_authentication == 1) {
 				char *response = packet_get_string(&dlen);
-				debug("skey response == '%s'", response);
-				packet_integrity_check(plen, 4 + dlen, type);
-				authenticated = (pw != NULL &&
-				    skey_haskey(pw->pw_name) == 0 &&
-				    skey_passcheck(pw->pw_name, response) != -1);
+				debug("got response '%s'", response);
+				packet_check_eom();
+				authenticated = verify_response(authctxt, response);
+				memset(response, 'r', dlen);
 				xfree(response);
 			}
 			break;
-#else
-		case SSH_CMSG_AUTH_TIS:
-			/* TIS Authentication is unsupported */
-			log("TIS authentication unsupported.");
-			break;
-#endif
 
 		default:
 			/*
@@ -291,46 +284,30 @@
 			log("Unknown message during authentication: type %d", type);
 			break;
 		}
-		if (authenticated && pw == NULL)
-			fatal("internal error: authenticated for pw == NULL");
-
-		/*
-		 * Check if the user is logging in as root and root logins
-		 * are disallowed.
-		 * Note that root login is allowed for forced commands.
-		 */
-		if (authenticated && pw && pw->pw_uid == 0 && !options.permit_root_login) {
-			if (forced_command) {
-				log("Root login accepted for forced command.");
-			} else {
-				authenticated = 0;
-				log("ROOT LOGIN REFUSED FROM %.200s",
-				    get_canonical_hostname());
-			}
+#ifdef BSD_AUTH
+		if (authctxt->as) {
+			auth_close(authctxt->as);
+			authctxt->as = NULL;
 		}
+#endif
+		if (!authctxt->valid && authenticated)
+			fatal("INTERNAL ERROR: authenticated invalid user %s",
+			    authctxt->user);
 
-		/* Raise logging level */
-		if (authenticated ||
-		    attempt == AUTH_FAIL_LOG ||
-		    type == SSH_CMSG_AUTH_PASSWORD)
-			authlog = log;
+		/* Special handling for root */
+		if (authenticated && authctxt->pw->pw_uid == 0 &&
+		    !auth_root_allowed(get_authname(type)))
+			authenticated = 0;
 
-		authlog("%s %s for %s%.100s from %.200s port %d%s",
-			authenticated ? "Accepted" : "Failed",
-			get_authname(type),
-			pw ? "" : "illegal user ",
-			pw && pw->pw_uid == 0 ? "ROOT" : luser,
-			get_remote_ipaddr(),
-			get_remote_port(),
-			user);
+		/* Log before sending the reply */
+		auth_log(authctxt, authenticated, get_authname(type), info);
 
 		if (authenticated)
 			return;
 
-		if (attempt > AUTH_FAIL_MAX)
-			packet_disconnect(AUTH_FAIL_MSG, luser);
+		if (authctxt->failures++ > AUTH_FAIL_MAX)
+			packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
 
-		/* Send a message indicating that the authentication attempt failed. */
 		packet_start(SSH_SMSG_FAILURE);
 		packet_send();
 		packet_write_wait();
@@ -342,47 +319,44 @@
  * been exchanged and encryption is enabled.
  */
 void
-do_authentication()
+do_authentication(void)
 {
-	struct passwd *pw, pwcopy;
-	int plen;
-	unsigned int ulen;
-	char *user;
+	Authctxt *authctxt;
+	struct passwd *pw;
+	u_int ulen;
+	char *p, *user, *style = NULL;
 
 	/* Get the name of the user that we wish to log in as. */
-	packet_read_expect(&plen, SSH_CMSG_USER);
+	packet_read_expect(SSH_CMSG_USER);
 
 	/* Get the user name. */
 	user = packet_get_string(&ulen);
-	packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
+	packet_check_eom();
 
-	setproctitle("%s", user);
+	if ((style = strchr(user, ':')) != NULL)
+		*style++ = '\0';
 
-#ifdef AFS
-	/* If machine has AFS, set process authentication group. */
-	if (k_hasafs()) {
-		k_setpag();
-		k_unlog();
-	}
-#endif /* AFS */
+	/* XXX - SSH.com Kerberos v5 braindeath. */
+	if ((p = strchr(user, '@')) != NULL)
+		*p = '\0';
 
+	authctxt = authctxt_new();
+	authctxt->user = user;
+	authctxt->style = style;
+
 	/* Verify that the user is a valid user. */
 	pw = getpwnam(user);
 	if (pw && allowed_user(pw)) {
-		/* Take a copy of the returned structure. */
-		memset(&pwcopy, 0, sizeof(pwcopy));
-		pwcopy.pw_name = xstrdup(pw->pw_name);
-		pwcopy.pw_passwd = xstrdup(pw->pw_passwd);
-		pwcopy.pw_uid = pw->pw_uid;
-		pwcopy.pw_gid = pw->pw_gid;
-		pwcopy.pw_class = xstrdup(pw->pw_class);
-		pwcopy.pw_dir = xstrdup(pw->pw_dir);
-		pwcopy.pw_shell = xstrdup(pw->pw_shell);
-		pw = &pwcopy;
+		authctxt->valid = 1;
+		pw = pwcopy(pw);
 	} else {
+		debug("do_authentication: illegal user %s", user);
 		pw = NULL;
 	}
+	authctxt->pw = pw;
 
+	setproctitle("%s", pw ? user : "unknown");
+
 	/*
 	 * If we are not running as root, the user must have the same uid as
 	 * the server.
@@ -390,31 +364,17 @@
 	if (getuid() != 0 && pw && pw->pw_uid != getuid())
 		packet_disconnect("Cannot change user when server not running as root.");
 
-	debug("Attempting authentication for %s%.100s.", pw ? "" : "illegal user ", user);
+	/*
+	 * Loop until the user has been authenticated or the connection is
+	 * closed, do_authloop() returns only if authentication is successful
+	 */
+	do_authloop(authctxt);
 
-	/* If the user has no password, accept authentication immediately. */
-	if (options.password_authentication &&
-#ifdef KRB4
-	    (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
-#endif /* KRB4 */
-	    auth_password(pw, "")) {
-		/* Authentication with empty password succeeded. */
-		log("Login for user %s from %.100s, accepted without authentication.",
-		    user, get_remote_ipaddr());
-	} else {
-		/* Loop until the user has been authenticated or the
-		   connection is closed, do_authloop() returns only if
-		   authentication is successfull */
-		do_authloop(pw, user);
-	}
-	if (pw == NULL)
-		fatal("internal error, authentication successfull for user '%.100s'", user);
-
 	/* The user has been authenticated and accepted. */
 	packet_start(SSH_SMSG_SUCCESS);
 	packet_send();
 	packet_write_wait();
 
 	/* Perform session preparation. */
-	do_authenticated(pw);
+	do_authenticated(authctxt);
 }