New files.

Rev: src/charset.c:1.1
Rev: src/charset.h:1.1
Rev: src/client_password.c:1.1
Rev: src/client_userauth.c:1.1
Rev: src/client_userauth.h:1.1
Rev: src/password.h:1.1
Rev: src/server_password.c:1.1

src/charset.c

+/* charset.c
+ *
+ * Translate local characterset to and from utf8.
+ *
+ * $Id$
+ */
+
+/* lsh, an implementation of the ssh protocol
+ *
+ * Copyright (C) 1998 Niels Mller
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "charset.h"
+
+#include <assert.h>
+
+static int local_charset;
+
+void set_local_charset(int charset)
+{
+  local_charset = charset;
+}
+
+UINT32 local_to_ucs4(int c)
+{
+  switch (local_charset)
+    {
+    case CHARSET_US_ASCII:
+    case CHARSET_LATIN1:
+      return (UINT32) c;
+    default:
+      fatal("Internal error");
+    };
+}
+
+/* NOTE: This function does not filter any control characters */
+int ucs4_to_local(UINT32 c)
+{
+  switch (local_charset)
+    {
+    case CHARSET_US_ASCII:
+      return (c < 0x80) ? c : -1;
+    case CHARSET_LATIN1:
+      return (c < 0x100) ? c : -1;
+    default:
+      fatal("Internal error");
+    };
+}
+
+struct lsh_string *local_to_utf8(struct lsh_string s, int free)
+{
+  switch (local_charset)
+    {
+    case CHARSET_UTF8:
+    case CHARSET_USASCII:
+      return s;
+    default:
+      {
+	UINT32 *chars = alloca(s->length * sizeof(UINT32));
+	unsigned char *lengths = alloca(s->length);
+
+	UINT32 total = 0;
+	{
+	  int i;
+	
+	  /* First convert to ucs-4, and compute the length of the corresponding
+	   * utf-8 string. */
+	  for (i = 0; i<s->length; i++)
+	    {
+	      UINT32 c = local_to_ucs4(s->data[i]);
+	      unsigned char l = 1;
+
+	      if (c >= (1L<<7))
+		{
+		  l++;
+		  if (c >= (1L<<11))
+		    {
+		      l++;
+		      if (c >= (1L<<16))
+			{
+			  l++;
+			  if (c >= (1L<<21))
+			    {
+			      l++;
+			      if (c >= (1L<<25))
+				{
+				  l++;
+				  if (c >= (1L<<31))
+				    fatal("Internal error!\n");
+				}}}}}
+	      chars[i] = c;
+	      lengths[i] = l;
+	      total += l;
+	    }
+	}
+	{
+	  struct lsh_string res = lsh_string_alloc(total);
+	  int i, j;
+
+	  for(i = j = 0; i<s->length; i++)
+	    {
+	      static const UINT8 *prefix
+		= {0, 0xC0, 0xE0, 0xF0, 0xF8, 0xFc };
+	      
+	      UINT32 c = chars[i];
+	      unsigned char l = lengths[i] - 1;
+	      int k;
+	      
+	      for (k = l; k; k--)
+		{
+		  res->data[j+k] = 0x80 | (c & 0x3f);
+		  c >>= 6;
+		}
+	      assert( !(prefix[l] & c) );
+	      res->data[j] = prefix[l] | c;
+
+	      j += lengths[i];
+	    }
+	  assert(j == total);
+
+	  if (free)
+	    lsh_string_free(s);
+
+	  return res;
+	}
+      }
+    }
+}
+  
+  
+struct lsh_string *utf8_to_local(struct lsh_string s, int free)
+{
+  int i;
+  struct lsh_string *res;
+  struct simple_buffer buffer;
+  
+  if (local_charset == CHARSET_UTF8)
+    return s;
+
+  /* The string can't grow when converted to local charset */
+  res = lsh_string_alloc(s->length);
+
+  simple_buffer_init(&buffer, s->length, s->data);
+
+  for (i = 0; 1; i++)
+    {
+      UINT32 ucs4;
+
+      switch(parse_utf8(&buffer, &ucs4))
+	{
+	case -1:
+	  assert(i<res->length);
+	  
+	  res->length = i;
+	  if (free)
+	    lsh_string_free(s);
+
+	  return res;
+
+	case 1:
+	  {
+	    int local = ucs4_to_local(ucs4);
+
+	    if (local >= 0)
+	      {
+		res->data[i] = local;
+		break;
+	      }
+	    /* Fall through */
+	  }
+	case 0: /* Error */
+	  lsh_string_free(res);
+	  if (free)
+	    lsh_string_free(s);
+	  return 0;
+
+	default:
+	  fatal("Internal error!\n");
+	}
+    }
+}

src/charset.h

+/* charset.h
+ *
+ * Translate local characterset to and from utf8.
+ *
+ * $Id$
+ */
+
+/* lsh, an implementation of the ssh protocol
+ *
+ * Copyright (C) 1998 Niels Möller
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef LSH_CHARSET_H_INCLUDED
+#define LSH_CHARSET_H_INCLUDED
+
+#include "lsh_types.h"
+
+/* FIXME: Use charsets real objects, instead of using fixed constants */
+
+#define CHARSET_UTF8 0
+#define CHARSET_LATIN1 1
+#define CHARSET_USASCII 2
+
+void set_local_charset(int charset);
+
+UINT32 local_to_ucs4(int c);
+int ucs4_to_local(UINT32 c);
+
+struct lsh_string *local_to_utf8(struct lsh_string s, int free);
+struct lsh_string *utf8_to_local(struct lsh_string s, int free);
+
+#endif /* LSH_CHARSET_H_INCLUDED */

src/client_password.c

+/* client_password.c
+ *
+ * System dependant password related functions.
+ */
+
+/* lsh, an implementation of the ssh protocol
+ *
+ * Copyright (C) 1998 Niels Mller
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "password.h"
+
+#include <stdarg.h>
+#include <string.h>
+
+#include <termios.h>
+
+int echo_on(int fd)
+{
+  struct termios t;
+
+  if (tcgetattr(fd, &t) < 0)
+    {
+      werror("Can't get terminal attributes: %s\n", strerror(errno));
+      return 0;
+    }
+
+  t->c_lflag |= ECHO;
+
+  if (tcsetattr(fd, TCSANOW, &t) < 0)
+    {
+      werror("Can't set terminal attributes: %s\n", strerror(errno));
+      return 0;
+    }
+
+  return 1;
+}
+
+int echo_off(int fd)
+{
+  struct termios t;
+
+  if (tcgetattr(fd, &t) < 0)
+    {
+      werror("Can't get terminal attributes: %s\n", strerror(errno));
+      return 0;
+    }
+
+  t->c_lflag &= ~ECHO;
+
+  if (tcsetattr(fd, TCSAFLUSH, &t) < 0)
+    {
+      werror("Can't set terminal attributes: %s\n", strerror(errno));
+      return 0;
+    }
+
+  return 1;
+}
+
+/* FIXME: Perhaps it is better to avoid using stdio functions? */
+struct lsh_string *read_password(int max_length, char *format, ...)
+{
+  va_list args;
+  int fd;
+  FILE *tty;
+
+  struct lsh_string *res;
+  
+  fd = open("/dev/tty", O_RDWR);
+
+  if (fd < 0)
+    {
+      werror("Can't open /dev/tty: %s\n", strerror(errno));
+      return 0;
+    }
+  tty = fdopen(fd, "rw");
+  if (!tty)
+    {
+      close(fd);
+      werror("Can't fdopen /dev/tty: %s\n", strerror(errno));
+      return 0;
+    }
+
+  /* Ignore errors */
+  (void) echo_off(fd);
+
+  va_start(args, format);
+  vfprintf(tty, format, format, args);
+  va_end(args);
+
+  fflush(tty);
+
+  res = lsh_string_alloc(max_length);
+  if (!fgets(res->data, max_length, tty))
+    res = 0;
+  else
+    {
+      res->length = strlen(res->data);
+      /* Delete terminating newline */
+      if (res->length && (res->data[res->length-1] == '\n'))
+	res->length--;
+    }
+
+  /* Ignore errors */
+  (void) echo_on(fd);
+	  
+  fclose(tty);
+
+  return res;
+}

src/client_userauth.c

+/* client_userauth.c
+ *
+ */
+
+/* lsh, an implementation of the ssh protocol
+ *
+ * Copyright (C) 1998 Niels Mller
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "userauth.h"
+#include "service.h"
+
+/* FIXME: For now, use only password authentication. A better method
+ * would be to first send a set of publickey authentication requests
+ * for the available keys (for some configurable value of
+ * "available"). This is analogous to unlocking a door by first
+ * examining the keys on one's keyring to see if any of them kan be
+ * inserted into the lock. Preferably, at this point one should use
+ * spki hashed public keys rather than the public keys themselves.
+ *
+ * Next we wait for SSH_MSH_USERAUTH_FAILURE or SSH_MSG_USERAUTH_PK_OK
+ * messages. If any of the keys is recognized, we compute a signature
+ * and send it to the server (analogously to inserting the key into
+ * the lock and turning it around).
+ *
+ * If none of the keys were recognized, or if no keys were available
+ *from the start, we ask the user for a password and attempts to log
+ *in using that. */
+
+struct client_userauth
+{
+  struct ssh_service super;
+
+  struct lsh_string username; /* Remote user name to authenticate as */
+  int service_name;   /* Service we want to access */
+  struct ssh_service *service;
+  
+  /* FIXME: Keys to try */
+};
+
+struct success_handler
+{
+  struct packet_handler super;
+
+  struct ssh_service *service;
+};
+
+struct failure_handler
+{
+  struct packet_handler super;
+
+  struct client_userauth *userauth;
+};
+
+struct lsh_string format_userauth_password(struct lsh_string name,
+					   int service,
+					   struct lsh_string passwd
+					   int free)
+{
+  return ssh_format(free ? "%c%S%a%a%c%fS" : "%c%S%a%a%c%S",
+		    SSH_MSG_USERAUTH_REQUEST,
+		    name,
+		    service,
+		    ATOM_PASSWORD,
+		    0,
+		    passwd);
+}
+
+#define MAX_PASSWD 100
+
+/* FIXME: Implement proper conversions from local charset */
+#define LOCAL_TO_UTF8(x, free) (x)
+
+static int send_passwd(struct client_userauth *userauth,
+		       struct ssh_connection *connection)
+{
+  struct lsh_string *passwd
+    = read_password(MAX_PASSWD, "Password for %s: ", userauth->name);
+
+  if (!passwd)
+    return LSH_FAIL | LSH_DIE;
+  
+  return A_WRITE(connection->write,
+		 format_userauth_password(LOCAL_TO_UTF8(userauth->name, 0),
+					  service,
+					  LOCAL_TO_UTF8(passwd, 1),
+					  1));
+}
+
+static int do_userauth_success(struct packet_handler *c,
+				struct ssh_connection *connection,
+				struct lsh_string *packet)
+{
+  struct success_handler *closure = (struct success_handler *) c;
+  struct simple_buffer buffer;
+
+  int msg_number;
+    
+  MDEBUG(closure);
+
+  simple_buffer_init(&buffer, packet->length, packet->data);
+
+  if (parse_uint8(&buffer, &msg_number)
+      && (msg_number == SSH_MSG_USERAUTH_SUCCESS)
+      && parse_eod(&buffer))
+    {
+      werror("User authentication successful.\n");
+
+      lsh_string_free(packet);
+      
+      connection->dispatch[SSH_MSG_USERAUTH_SUCCESS] = connection->fail;
+      connection->dispatch[SSH_MSG_USERAUTH_FAILURE] = connection->fail;
+      connection->dispatch[SSH_MSG_USERAUTH_BANNER] = connection->fail;
+      
+      return SERVICE_INIT(closure->service, connection);
+    }
+  
+  lsh_string_free(packet);
+  return LSH_FAIL | LSSH_DIE;
+}
+
+static int do_userauth_failure(struct packet_handler *c,
+			       struct ssh_connection *connection,
+			       struct lsh_string *packet)
+{
+  struct failure_handler *closure = (struct failure_handler *) c;
+  struct simple_buffer buffer;
+
+  int msg_number;
+  int *methods = NULL;
+  int partial_success:
+    
+  MDEBUG(closure);
+
+  simple_buffer_init(&buffer, packet->length, packet->data);
+
+  if (parse_uint8(&buffer, &msg_number)
+      && (msg_number == SSH_MSG_USERAUTH_FAILURE)
+      && parse_atoms(&buffer, &methods)
+      && parse_boolean(&buffer, &methods)
+      && parse_eod(&buffer))
+    {
+      int i;
+      
+      lsh_string_free(packet);
+
+      if (partial_success)
+	{ /* Doesn't help us */
+	  werror("Recieved SSH_MSH_USERAUTH_FAILURE "
+		 "indicating partial success.\n")
+	  lsh_free(methods);
+
+	  return LSH_FAIL | LSH_DIE;
+	}
+      for(i = 0; methods[i] >= 0; i++)
+	if (methods[i] == ATOM_PASSWORD)
+	  {
+	    /* Try again */
+	    lsh_free(methods);
+	    return send_passwd(closure->userauth, connection);
+	  }
+      /* No methods that we can use */
+      lsh_free(methods);
+      return LSH_FAIL | LSH_DIE;
+    }
+
+  if (methods)
+    lsh_free(methods);
+  
+  lsh_string_free(packet);
+  return LSH_FAIL | LSSH_DIE;
+}
+
+static int do_userauth_banner(struct packet_handler *closure
+			      struct ssh_connection *connection,
+			      struct lsh_string *packet)
+{
+  struct simple_buffer buffer;
+
+  int msg_number;
+  UINT32 length;
+  UINT8 *mesg;
+
+  UINT32 language_length;
+  UINT8 *language;
+  
+  MDEBUG(closure);
+
+  simple_buffer_init(&buffer, packet->length, packet->data);
+
+  if (parse_uint8(&buffer, &msg_number)
+      && (msg_number == SSH_MSG_USERAUTH_BANNER)
+      && parse_string(&buffer, &length, &msg)
+      && parse_string(&buffer, &language_length, &language)
+      && parse_eod(&buffer))
+    {
+      /* Ignore language tag */
+      werror_utf8(length, msg);
+
+      lsh_string_free(packet);
+      return LSH_OK | LSH_GOON;
+    }
+  lsh_free(packet);
+  return LSH_FAIL | LSH_DIE;
+}
+
+static struct packet_handler *make_success_handler(struct ssh_service *service)
+{
+  struct success_handler *self;
+
+  NEW(self);
+  self->super.handler = do_userauth_success;
+  self->service = service;
+
+  return &self->super;
+}
+
+static struct packet_handler *
+make_failure_handler(struct client_userauth *userauth)
+{
+  struct failure_handler *self;
+
+  NEW(self);
+  self->super.handler = do_userauth_failure;
+  self->userauth = userauth;
+
+  return &self->super;
+}
+
+static struct packet_handler *make_banner_handler()
+{
+  struct packet_handler *self;
+
+  NEW(self);
+  self->handler = do_userauth_banner;
+  
+  return &self->super;
+}
+
+static int init_client_userauth(struct ssh_service *c,
+				struct ssh_connection *connection)
+{
+  struct client_userauth *closure = (struct client_userauth *) c;
+
+  MDEBUG(closure);
+
+  connection->dispatch[SSH_MSG_USERAUTH_SUCCESS]
+    = make_success_handler(closure->service);
+  connection->dispatch[SSH_MSG_USERAUTH_FAILURE]
+    = make_failure_handler(closure);
+  connection->dispatch[SSH_MSG_USERAUTH_BANNER]
+    = make_banner_handler();
+
+  return send_passwd(closure, connection);
+}
+
+struct ssh_service *make_client_userauth(struct lsh_string username,
+