openssh/buffer.c

253 lines
5.6 KiB
C
Raw Normal View History

- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
2006-08-05 10:39:39 +08:00
/* $OpenBSD: buffer.c,v 1.31 2006/08/03 03:34:41 deraadt Exp $ */
1999-10-27 11:42:43 +08:00
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Functions for manipulating fifo buffers (that can grow if needed).
*
- (djm) Merge OpenBSD changes: - markus@cvs.openbsd.org 2000/09/05 02:59:57 [session.c] print hostname (not hushlogin) - markus@cvs.openbsd.org 2000/09/05 13:18:48 [authfile.c ssh-add.c] enable ssh-add -d for DSA keys - markus@cvs.openbsd.org 2000/09/05 13:20:49 [sftp-server.c] cleanup - markus@cvs.openbsd.org 2000/09/06 03:46:41 [authfile.h] prototype - deraadt@cvs.openbsd.org 2000/09/07 14:27:56 [ALL] cleanup copyright notices on all files. I have attempted to be accurate with the details. everything is now under Tatu's licence (which I copied from his readme), and/or the core-sdi bsd-ish thing for deattack, or various openbsd developers under a 2-term bsd licence. We're not changing any rules, just being accurate. - markus@cvs.openbsd.org 2000/09/07 14:40:30 [channels.c channels.h clientloop.c serverloop.c ssh.c] cleanup window and packet sizes for ssh2 flow control; ok niels - markus@cvs.openbsd.org 2000/09/07 14:53:00 [scp.c] typo - markus@cvs.openbsd.org 2000/09/07 15:13:37 [auth-options.c auth-options.h auth-rh-rsa.c auth-rsa.c auth.c] [authfile.h canohost.c channels.h compat.c hostfile.h log.c match.h] [pty.c readconf.c] some more Copyright fixes - markus@cvs.openbsd.org 2000/09/08 03:02:51 [README.openssh2] bye bye - deraadt@cvs.openbsd.org 2000/09/11 18:38:33 [LICENCE cipher.c] a few more comments about it being ARC4 not RC4 - markus@cvs.openbsd.org 2000/09/12 14:53:11 [log-client.c log-server.c log.c ssh.1 ssh.c ssh.h sshd.8 sshd.c] multiple debug levels - markus@cvs.openbsd.org 2000/09/14 14:25:15 [clientloop.c] typo - deraadt@cvs.openbsd.org 2000/09/15 01:13:51 [ssh-agent.c] check return value for setenv(3) for failure, and deal appropriately
2000-09-16 10:29:08 +08:00
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
1999-10-27 11:42:43 +08:00
#include "includes.h"
#include <sys/param.h>
#include <stdio.h>
#include <string.h>
- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
2006-08-05 10:39:39 +08:00
#include <stdarg.h>
1999-10-27 11:42:43 +08:00
#include "xmalloc.h"
#include "buffer.h"
Hopefully things did not get mixed around too much. It compiles under Linux and works. So that is at least a good sign. =) 20010122 - (bal) OpenBSD Resync - markus@cvs.openbsd.org 2001/01/19 12:45:26 GMT 2001 by markus [servconf.c ssh.h sshd.c] only auth-chall.c needs #ifdef SKEY - markus@cvs.openbsd.org 2001/01/19 15:55:10 GMT 2001 by markus [auth-krb4.c auth-options.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c auth2.c channels.c clientloop.c dh.c dispatch.c nchan.c packet.c pathname.h readconf.c scp.c servconf.c serverloop.c session.c ssh-add.c ssh-keygen.c ssh-keyscan.c ssh.c ssh.h ssh1.h sshconnect1.c sshd.c ttymodes.c] move ssh1 definitions to ssh1.h, pathnames to pathnames.h - markus@cvs.openbsd.org 2001/01/19 16:48:14 [sshd.8] fix typo; from stevesk@ - markus@cvs.openbsd.org 2001/01/19 16:50:58 [ssh-dss.c] clear and free digest, make consistent with other code (use dlen); from stevesk@ - markus@cvs.openbsd.org 2001/01/20 15:55:20 GMT 2001 by markus [auth-options.c auth-options.h auth-rsa.c auth2.c] pass the filename to auth_parse_options() - markus@cvs.openbsd.org 2001/01/20 17:59:40 GMT 2001 [readconf.c] fix SIGSEGV from -o ""; problem noted by jehsom@togetherweb.com - stevesk@cvs.openbsd.org 2001/01/20 18:20:29 [sshconnect2.c] dh_new_group() does not return NULL. ok markus@ - markus@cvs.openbsd.org 2001/01/20 21:33:42 [ssh-add.c] do not loop forever if askpass does not exist; from andrew@pimlott.ne.mediaone.net - djm@cvs.openbsd.org 2001/01/20 23:00:56 [servconf.c] Check for NULL return from strdelim; ok markus - djm@cvs.openbsd.org 2001/01/20 23:02:07 [readconf.c] KNF; ok markus - jakob@cvs.openbsd.org 2001/01/21 9:00:33 [ssh-keygen.1] remove -R flag; ok markus@ - markus@cvs.openbsd.org 2001/01/21 19:05:40 [atomicio.c automicio.h auth-chall.c auth-krb4.c auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth.c auth.h auth1.c auth2-chall.c auth2.c authfd.c authfile.c bufaux.c bufaux.h buffer.c canahost.c canahost.h channels.c cipher.c cli.c clientloop.c clientloop.h compat.c compress.c deattack.c dh.c dispatch.c groupaccess.c hmac.c hostfile.c kex.c key.c key.h log-client.c log-server.c log.c log.h login.c login.h match.c misc.c misc.h nchan.c packet.c pty.c radix.h readconf.c readpass.c readpass.h rsa.c scp.c servconf.c serverloop.c serverloop.h session.c sftp-server.c ssh-add.c ssh-agent.c ssh-dss.c ssh-keygen.c ssh-keyscan.c ssh-rsa.c ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c sshd.c tildexpand.c tildexpand.h ttysmodes.c uidswap.c xmalloc.c] split ssh.h and try to cleanup the #include mess. remove unnecessary #includes. rename util.[ch] -> misc.[ch] - (bal) renamed 'PIDDIR' to '_PATH_SSH_PIDDIR' to match OpenBSD tree - (bal) Moved #ifdef KRB4 in auth-krb4.c above the #include to resolve conflict when compiling for non-kerb install - (bal) removed the #ifdef SKEY in auth1.c to match Markus' changes on 1/19.
2001-01-22 13:34:40 +08:00
#include "log.h"
1999-10-27 11:42:43 +08:00
#define BUFFER_MAX_CHUNK 0x100000
#define BUFFER_MAX_LEN 0xa00000
#define BUFFER_ALLOCSZ 0x008000
1999-10-27 11:42:43 +08:00
/* Initializes the buffer structure. */
void
buffer_init(Buffer *buffer)
1999-10-27 11:42:43 +08:00
{
const u_int len = 4096;
buffer->alloc = 0;
buffer->buf = xmalloc(len);
buffer->alloc = len;
buffer->offset = 0;
buffer->end = 0;
1999-10-27 11:42:43 +08:00
}
/* Frees any memory used for the buffer. */
void
buffer_free(Buffer *buffer)
1999-10-27 11:42:43 +08:00
{
if (buffer->alloc > 0) {
memset(buffer->buf, 0, buffer->alloc);
buffer->alloc = 0;
xfree(buffer->buf);
}
1999-10-27 11:42:43 +08:00
}
/*
* Clears any data from the buffer, making it empty. This does not actually
* zero the memory.
*/
1999-10-27 11:42:43 +08:00
void
buffer_clear(Buffer *buffer)
1999-10-27 11:42:43 +08:00
{
buffer->offset = 0;
buffer->end = 0;
1999-10-27 11:42:43 +08:00
}
/* Appends data to the buffer, expanding it if necessary. */
void
buffer_append(Buffer *buffer, const void *data, u_int len)
1999-10-27 11:42:43 +08:00
{
void *p;
p = buffer_append_space(buffer, len);
memcpy(p, data, len);
1999-10-27 11:42:43 +08:00
}
static int
buffer_compact(Buffer *buffer)
{
/*
* If the buffer is quite empty, but all data is at the end, move the
* data to the beginning.
*/
if (buffer->offset > MIN(buffer->alloc, BUFFER_MAX_CHUNK)) {
memmove(buffer->buf, buffer->buf + buffer->offset,
buffer->end - buffer->offset);
buffer->end -= buffer->offset;
buffer->offset = 0;
return (1);
}
return (0);
}
/*
* Appends space to the buffer, expanding the buffer if necessary. This does
* not actually copy the data into the buffer, but instead returns a pointer
* to the allocated region.
*/
1999-10-27 11:42:43 +08:00
void *
buffer_append_space(Buffer *buffer, u_int len)
1999-10-27 11:42:43 +08:00
{
u_int newlen;
void *p;
if (len > BUFFER_MAX_CHUNK)
fatal("buffer_append_space: len %u not supported", len);
/* If the buffer is empty, start using it from the beginning. */
if (buffer->offset == buffer->end) {
buffer->offset = 0;
buffer->end = 0;
}
restart:
/* If there is enough space to store all data, store it now. */
if (buffer->end + len < buffer->alloc) {
p = buffer->buf + buffer->end;
buffer->end += len;
return p;
}
/* Compact data back to the start of the buffer if necessary */
if (buffer_compact(buffer))
goto restart;
2003-11-21 20:56:47 +08:00
/* Increase the size of the buffer and retry. */
newlen = roundup(buffer->alloc + len, BUFFER_ALLOCSZ);
if (newlen > BUFFER_MAX_LEN)
fatal("buffer_append_space: alloc %u not supported",
newlen);
buffer->buf = xrealloc(buffer->buf, 1, newlen);
buffer->alloc = newlen;
goto restart;
/* NOTREACHED */
1999-10-27 11:42:43 +08:00
}
/*
* Check whether an allocation of 'len' will fit in the buffer
* This must follow the same math as buffer_append_space
*/
int
buffer_check_alloc(Buffer *buffer, u_int len)
{
if (buffer->offset == buffer->end) {
buffer->offset = 0;
buffer->end = 0;
}
restart:
if (buffer->end + len < buffer->alloc)
return (1);
if (buffer_compact(buffer))
goto restart;
if (roundup(buffer->alloc + len, BUFFER_ALLOCSZ) <= BUFFER_MAX_LEN)
return (1);
return (0);
}
1999-10-27 11:42:43 +08:00
/* Returns the number of bytes of data in the buffer. */
u_int
buffer_len(Buffer *buffer)
1999-10-27 11:42:43 +08:00
{
return buffer->end - buffer->offset;
1999-10-27 11:42:43 +08:00
}
/* Gets data from the beginning of the buffer. */
int
buffer_get_ret(Buffer *buffer, void *buf, u_int len)
1999-10-27 11:42:43 +08:00
{
if (len > buffer->end - buffer->offset) {
error("buffer_get_ret: trying to get more bytes %d than in buffer %d",
len, buffer->end - buffer->offset);
return (-1);
}
memcpy(buf, buffer->buf + buffer->offset, len);
buffer->offset += len;
return (0);
}
void
buffer_get(Buffer *buffer, void *buf, u_int len)
{
if (buffer_get_ret(buffer, buf, len) == -1)
fatal("buffer_get: buffer error");
1999-10-27 11:42:43 +08:00
}
/* Consumes the given number of bytes from the beginning of the buffer. */
int
buffer_consume_ret(Buffer *buffer, u_int bytes)
{
if (bytes > buffer->end - buffer->offset) {
error("buffer_consume_ret: trying to get more bytes than in buffer");
return (-1);
}
buffer->offset += bytes;
return (0);
}
void
buffer_consume(Buffer *buffer, u_int bytes)
1999-10-27 11:42:43 +08:00
{
if (buffer_consume_ret(buffer, bytes) == -1)
fatal("buffer_consume: buffer error");
}
1999-10-27 11:42:43 +08:00
/* Consumes the given number of bytes from the end of the buffer. */
int
buffer_consume_end_ret(Buffer *buffer, u_int bytes)
{
if (bytes > buffer->end - buffer->offset)
return (-1);
buffer->end -= bytes;
return (0);
}
void
buffer_consume_end(Buffer *buffer, u_int bytes)
1999-10-27 11:42:43 +08:00
{
if (buffer_consume_end_ret(buffer, bytes) == -1)
fatal("buffer_consume_end: trying to get more bytes than in buffer");
}
1999-10-27 11:42:43 +08:00
/* Returns a pointer to the first used byte in the buffer. */
void *
buffer_ptr(Buffer *buffer)
1999-10-27 11:42:43 +08:00
{
return buffer->buf + buffer->offset;
1999-10-27 11:42:43 +08:00
}
/* Dumps the contents of the buffer to stderr. */
void
buffer_dump(Buffer *buffer)
1999-10-27 11:42:43 +08:00
{
u_int i;
u_char *ucp = buffer->buf;
for (i = buffer->offset; i < buffer->end; i++) {
fprintf(stderr, "%02x", ucp[i]);
if ((i-buffer->offset)%16==15)
fprintf(stderr, "\r\n");
else if ((i-buffer->offset)%2==1)
fprintf(stderr, " ");
}
fprintf(stderr, "\r\n");
1999-10-27 11:42:43 +08:00
}