- (djm) OpenBSD CVS changes:

   - markus@cvs.openbsd.org  2000/07/22 03:14:37
     [servconf.c servconf.h sshd.8 sshd.c sshd_config]
     random early drop; ok theo, niels
   - deraadt@cvs.openbsd.org 2000/07/26 11:46:51
     [ssh.1]
     typo
   - deraadt@cvs.openbsd.org 2000/08/01 11:46:11
     [sshd.8]
     many fixes from pepper@mail.reppep.com
   - provos@cvs.openbsd.org  2000/08/01 13:01:42
     [Makefile.in util.c aux.c]
     rename aux.c to util.c to help with cygwin port
   - deraadt@cvs.openbsd.org 2000/08/02 00:23:31
     [authfd.c]
     correct sun_len; Alexander@Leidinger.net
   - provos@cvs.openbsd.org  2000/08/02 10:27:17
     [readconf.c sshd.8]
     disable kerberos authentication by default
   - provos@cvs.openbsd.org  2000/08/02 11:27:05
     [sshd.8 readconf.c auth-krb4.c]
     disallow kerberos authentication if we can't verify the TGT; from
     dugsong@
     kerberos authentication is on by default only if you have a srvtab.
   - markus@cvs.openbsd.org  2000/08/04 14:30:07
     [auth.c]
     unused
   - markus@cvs.openbsd.org  2000/08/04 14:30:35
     [sshd_config]
     MaxStartups
   - markus@cvs.openbsd.org  2000/08/15 13:20:46
     [authfd.c]
     cleanup; ok niels@
   - markus@cvs.openbsd.org  2000/08/17 14:05:10
     [session.c]
     cleanup login(1)-like jobs, no duplicate utmp entries
   - markus@cvs.openbsd.org  2000/08/17 14:06:34
     [session.c sshd.8 sshd.c]
      sshd -u len, similar to telnetd

1 files changed, 121 insertions, 204 deletions

diff --git a/authfd.c b/authfd.c
index 227c99286..a34e111ac 100644
--- a/authfd.c
+++ b/authfd.c
@@ -14,7 +14,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: authfd.c,v 1.22 2000/07/16 08:27:20 markus Exp $");
+RCSID("$OpenBSD: authfd.c,v 1.24 2000/08/15 19:20:46 markus Exp $");
 
 #include "ssh.h"
 #include "rsa.h"
@@ -31,7 +31,7 @@ RCSID("$OpenBSD: authfd.c,v 1.22 2000/07/16 08:27:20 markus Exp $");
 #include "kex.h"
 
 /* helper */
-int ssh_agent_get_reply(AuthenticationConnection *auth);
+int     decode_reply(int type);
 
 /* Returns the number of the authentication fd, or -1 if there is none. */
 
@@ -39,7 +39,7 @@ int
 ssh_get_authentication_socket()
 {
         const char *authsocket;
-        int sock;
+        int sock, len;
         struct sockaddr_un sunaddr;
 
         authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
@@ -48,6 +48,11 @@ ssh_get_authentication_socket()
 
         sunaddr.sun_family = AF_UNIX;
         strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
+#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN
+        sunaddr.sun_len = len = SUN_LEN(&sunaddr)+1;
+#else /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
+        len = SUN_LEN(&sunaddr)+1;
+#endif /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
 
         sock = socket(AF_UNIX, SOCK_STREAM, 0);
         if (sock < 0)
@@ -58,13 +63,67 @@ ssh_get_authentication_socket()
                 close(sock);
                 return -1;
         }
-        if (connect(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
+        if (connect(sock, (struct sockaddr *) & sunaddr, len) < 0) {
                 close(sock);
                 return -1;
         }
         return sock;
 }
 
+int
+ssh_request_reply(AuthenticationConnection *auth,
+    Buffer *request, Buffer *reply)
+{
+        int l, len;
+        char buf[1024];
+
+        /* Get the length of the message, and format it in the buffer. */
+        len = buffer_len(request);
+        PUT_32BIT(buf, len);
+
+        /* Send the length and then the packet to the agent. */
+        if (atomicio(write, auth->fd, buf, 4) != 4 ||
+            atomicio(write, auth->fd, buffer_ptr(request),
+            buffer_len(request)) != buffer_len(request)) {
+                error("Error writing to authentication socket.");
+                return 0;
+        }
+        /*
+         * Wait for response from the agent.  First read the length of the
+         * response packet.
+         */
+        len = 4;
+        while (len > 0) {
+                l = read(auth->fd, buf + 4 - len, len);
+                if (l <= 0) {
+                        error("Error reading response length from authentication socket.");
+                        return 0;
+                }
+                len -= l;
+        }
+
+        /* Extract the length, and check it for sanity. */
+        len = GET_32BIT(buf);
+        if (len > 256 * 1024)
+                fatal("Authentication response too long: %d", len);
+
+        /* Read the rest of the response in to the buffer. */
+        buffer_clear(reply);
+        while (len > 0) {
+                l = len;
+                if (l > sizeof(buf))
+                        l = sizeof(buf);
+                l = read(auth->fd, buf, l);
+                if (l <= 0) {
+                        error("Error reading response from authentication socket.");
+                        return 0;
+                }
+                buffer_append(reply, (char *) buf, l);
+                len -= l;
+        }
+        return 1;
+}
+
 /*
  * Closes the agent socket if it should be closed (depends on how it was
  * obtained).  The argument must have been returned by
@@ -133,62 +192,35 @@ ssh_close_authentication_connection(AuthenticationConnection *ac)
 
 int
 ssh_get_first_identity(AuthenticationConnection *auth,
-                       BIGNUM *e, BIGNUM *n, char **comment)
+    BIGNUM *e, BIGNUM *n, char **comment)
 {
-        unsigned char msg[8192];
-        int len, l;
+        Buffer request;
+        int type;
 
         /*
          * Send a message to the agent requesting for a list of the
          * identities it can represent.
          */
-        PUT_32BIT(msg, 1);
-        msg[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
-        if (atomicio(write, auth->fd, msg, 5) != 5) {
-                error("write auth->fd: %.100s", strerror(errno));
-                return 0;
-        }
-        /* Read the length of the response.  XXX implement timeouts here. */
-        len = 4;
-        while (len > 0) {
-                l = read(auth->fd, msg + 4 - len, len);
-                if (l <= 0) {
-                        error("read auth->fd: %.100s", strerror(errno));
-                        return 0;
-                }
-                len -= l;
-        }
-
-        /*
-         * Extract the length, and check it for sanity.  (We cannot trust
-         * authentication agents).
-         */
-        len = GET_32BIT(msg);
-        if (len < 1 || len > 256 * 1024)
-                fatal("Authentication reply message too long: %d\n", len);
+        buffer_init(&request);
+        buffer_put_char(&request, SSH_AGENTC_REQUEST_RSA_IDENTITIES);
 
-        /* Read the packet itself. */
         buffer_clear(&auth->identities);
-        while (len > 0) {
-                l = len;
-                if (l > sizeof(msg))
-                        l = sizeof(msg);
-                l = read(auth->fd, msg, l);
-                if (l <= 0)
-                        fatal("Incomplete authentication reply.");
-                buffer_append(&auth->identities, (char *) msg, l);
-                len -= l;
+        if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
+                buffer_free(&request);
+                return 0;
         }
+        buffer_free(&request);
 
         /* Get message type, and verify that we got a proper answer. */
-        buffer_get(&auth->identities, (char *) msg, 1);
-        if (msg[0] != SSH_AGENT_RSA_IDENTITIES_ANSWER)
-                fatal("Bad authentication reply message type: %d", msg[0]);
+        type = buffer_get_char(&auth->identities);
+        if (type != SSH_AGENT_RSA_IDENTITIES_ANSWER)
+                fatal("Bad authentication reply message type: %d", type);
 
         /* Get the number of entries in the response and check it for sanity. */
         auth->howmany = buffer_get_int(&auth->identities);
         if (auth->howmany > 1024)
-                fatal("Too many identities in authentication reply: %d\n", auth->howmany);
+                fatal("Too many identities in authentication reply: %d\n",
+                    auth->howmany);
 
         /* Return the first entry (if any). */
         return ssh_get_next_identity(auth, e, n, comment);
@@ -203,7 +235,7 @@ ssh_get_first_identity(AuthenticationConnection *auth,
 
 int
 ssh_get_next_identity(AuthenticationConnection *auth,
-                      BIGNUM *e, BIGNUM *n, char **comment)
+    BIGNUM *e, BIGNUM *n, char **comment)
 {
         unsigned int bits;
 
@@ -240,23 +272,22 @@ ssh_get_next_identity(AuthenticationConnection *auth,
 
 int
 ssh_decrypt_challenge(AuthenticationConnection *auth,
-                      BIGNUM* e, BIGNUM *n, BIGNUM *challenge,
-                      unsigned char session_id[16],
-                      unsigned int response_type,
-                      unsigned char response[16])
+    BIGNUM* e, BIGNUM *n, BIGNUM *challenge,
+    unsigned char session_id[16],
+    unsigned int response_type,
+    unsigned char response[16])
 {
         Buffer buffer;
-        unsigned char buf[8192];
-        int len, l, i;
+        int success = 0;
+        int i;
+        int type;
 
-        /* Response type 0 is no longer supported. */
         if (response_type == 0)
-                fatal("Compatibility with ssh protocol version 1.0 no longer supported.");
+                fatal("Compatibility with ssh protocol version "
+                    "1.0 no longer supported.");
 
-        /* Format a message to the agent. */
-        buf[0] = SSH_AGENTC_RSA_CHALLENGE;
         buffer_init(&buffer);
-        buffer_append(&buffer, (char *) buf, 1);
+        buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
         buffer_put_int(&buffer, BN_num_bits(n));
         buffer_put_bignum(&buffer, e);
         buffer_put_bignum(&buffer, n);
@@ -264,77 +295,27 @@ ssh_decrypt_challenge(AuthenticationConnection *auth,
         buffer_append(&buffer, (char *) session_id, 16);
         buffer_put_int(&buffer, response_type);
 
-        /* Get the length of the message, and format it in the buffer. */
-        len = buffer_len(&buffer);
-        PUT_32BIT(buf, len);
-
-        /* Send the length and then the packet to the agent. */
-        if (atomicio(write, auth->fd, buf, 4) != 4 ||
-            atomicio(write, auth->fd, buffer_ptr(&buffer),
-            buffer_len(&buffer)) != buffer_len(&buffer)) {
-                error("Error writing to authentication socket.");
-error_cleanup:
+        if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
                 buffer_free(&buffer);
                 return 0;
         }
-        /*
-         * Wait for response from the agent.  First read the length of the
-         * response packet.
-         */
-        len = 4;
-        while (len > 0) {
-                l = read(auth->fd, buf + 4 - len, len);
-                if (l <= 0) {
-                        error("Error reading response length from authentication socket.");
-                        goto error_cleanup;
-                }
-                len -= l;
-        }
-
-        /* Extract the length, and check it for sanity. */
-        len = GET_32BIT(buf);
-        if (len > 256 * 1024)
-                fatal("Authentication response too long: %d", len);
-
-        /* Read the rest of the response in tothe buffer. */
-        buffer_clear(&buffer);
-        while (len > 0) {
-                l = len;
-                if (l > sizeof(buf))
-                        l = sizeof(buf);
-                l = read(auth->fd, buf, l);
-                if (l <= 0) {
-                        error("Error reading response from authentication socket.");
-                        goto error_cleanup;
-                }
-                buffer_append(&buffer, (char *) buf, l);
-                len -= l;
-        }
-
-        /* Get the type of the packet. */
-        buffer_get(&buffer, (char *) buf, 1);
+        type = buffer_get_char(&buffer);
 
-        /* Check for agent failure message. */
-        if (buf[0] == SSH_AGENT_FAILURE) {
+        if (type == SSH_AGENT_FAILURE) {
                 log("Agent admitted failure to authenticate using the key.");
-                goto error_cleanup;
+        } else if (type != SSH_AGENT_RSA_RESPONSE) {
+                fatal("Bad authentication response: %d", type);
+        } else {
+                success = 1;
+                /*
+                 * Get the response from the packet.  This will abort with a
+                 * fatal error if the packet is corrupt.
+                 */
+                for (i = 0; i < 16; i++)
+                        response[i] = buffer_get_char(&buffer);
         }
-        /* Now it must be an authentication response packet. */
-        if (buf[0] != SSH_AGENT_RSA_RESPONSE)
-                fatal("Bad authentication response: %d", buf[0]);
-
-        /*
-         * Get the response from the packet.  This will abort with a fatal
-         * error if the packet is corrupt.
-         */
-        for (i = 0; i < 16; i++)
-                response[i] = buffer_get_char(&buffer);
-
-        /* The buffer containing the packet is no longer needed. */
         buffer_free(&buffer);
-
-        /* Correct answer. */
-        return 1;
+        return success;
 }
 
 /* Encode key for a message to the agent. */
@@ -378,8 +359,7 @@ int
 ssh_add_identity(AuthenticationConnection *auth, Key *key, const char *comment)
 {
         Buffer buffer;
-        unsigned char buf[8192];
-        int len;
+        int type;
 
         buffer_init(&buffer);
 
@@ -395,21 +375,13 @@ ssh_add_identity(AuthenticationConnection *auth, Key *key, const char *comment)
                 return 0;
                 break;
         }
-
-        /* Get the length of the message, and format it in the buffer. */
-        len = buffer_len(&buffer);
-        PUT_32BIT(buf, len);
-
-        /* Send the length and then the packet to the agent. */
-        if (atomicio(write, auth->fd, buf, 4) != 4 ||
-            atomicio(write, auth->fd, buffer_ptr(&buffer),
-            buffer_len(&buffer)) != buffer_len(&buffer)) {
-                error("Error writing to authentication socket.");
+        if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
                 buffer_free(&buffer);
                 return 0;
         }
+        type = buffer_get_char(&buffer);
         buffer_free(&buffer);
-        return ssh_agent_get_reply(auth);
+        return decode_reply(type);
 }
 
 /*
@@ -421,30 +393,21 @@ int
 ssh_remove_identity(AuthenticationConnection *auth, RSA *key)
 {
         Buffer buffer;
-        unsigned char buf[5];
-        int len;
+        int type;
 
-        /* Format a message to the agent. */
         buffer_init(&buffer);
         buffer_put_char(&buffer, SSH_AGENTC_REMOVE_RSA_IDENTITY);
         buffer_put_int(&buffer, BN_num_bits(key->n));
         buffer_put_bignum(&buffer, key->e);
         buffer_put_bignum(&buffer, key->n);
 
-        /* Get the length of the message, and format it in the buffer. */
-        len = buffer_len(&buffer);
-        PUT_32BIT(buf, len);
-
-        /* Send the length and then the packet to the agent. */
-        if (atomicio(write, auth->fd, buf, 4) != 4 ||
-            atomicio(write, auth->fd, buffer_ptr(&buffer),
-            buffer_len(&buffer)) != buffer_len(&buffer)) {
-                error("Error writing to authentication socket.");
+        if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
                 buffer_free(&buffer);
                 return 0;
         }
+        type = buffer_get_char(&buffer);
         buffer_free(&buffer);
-        return ssh_agent_get_reply(auth);
+        return decode_reply(type);
 }
 
 /*
@@ -455,73 +418,27 @@ ssh_remove_identity(AuthenticationConnection *auth, RSA *key)
 int
 ssh_remove_all_identities(AuthenticationConnection *auth)
 {
-        unsigned char buf[5];
+        Buffer buffer;
+        int type;
 
-        /* Get the length of the message, and format it in the buffer. */
-        PUT_32BIT(buf, 1);
-        buf[4] = SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES;
+        buffer_init(&buffer);
+        buffer_put_char(&buffer, SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES);
 
-        /* Send the length and then the packet to the agent. */
-        if (atomicio(write, auth->fd, buf, 5) != 5) {
-                error("Error writing to authentication socket.");
+        if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
+                buffer_free(&buffer);
                 return 0;
         }
-        return ssh_agent_get_reply(auth);
+        type = buffer_get_char(&buffer);
+        buffer_free(&buffer);
+        return decode_reply(type);
 }
 
-/*
- * Read for reply from agent. returns 1 for success, 0 on error
- */
-
 int 
-ssh_agent_get_reply(AuthenticationConnection *auth)
+decode_reply(int type)
 {
-        Buffer buffer;
-        unsigned char buf[8192];
-        int len, l, type;
-
-        /*
-         * Wait for response from the agent.  First read the length of the
-         * response packet.
-         */
-        len = 4;
-        while (len > 0) {
-                l = read(auth->fd, buf + 4 - len, len);
-                if (l <= 0) {
-                        error("Error reading response length from authentication socket.");
-                        buffer_free(&buffer);
-                        return 0;
-                }
-                len -= l;
-        }
-
-        /* Extract the length, and check it for sanity. */
-        len = GET_32BIT(buf);
-        if (len > 256 * 1024)
-                fatal("Response from agent too long: %d", len);
-
-        /* Read the rest of the response in to the buffer. */
-        buffer_init(&buffer);
-        while (len > 0) {
-                l = len;
-                if (l > sizeof(buf))
-                        l = sizeof(buf);
-                l = read(auth->fd, buf, l);
-                if (l <= 0) {
-                        error("Error reading response from authentication socket.");
-                        buffer_free(&buffer);
-                        return 0;
-                }
-                buffer_append(&buffer, (char *) buf, l);
-                len -= l;
-        }
-
-        /* Get the type of the packet. */
-        type = buffer_get_char(&buffer);
-        buffer_free(&buffer);
         switch (type) {
         case SSH_AGENT_FAILURE:
-log("SSH_AGENT_FAILURE");
+                log("SSH_AGENT_FAILURE");
                 return 0;
         case SSH_AGENT_SUCCESS:
                 return 1;