Date: Sat, 17 Mar 2001 19:01:45 -0500 From: Will Andrews <will@physics.purdue.edu> To: arch@FreeBSD.org Cc: Luke Mewburn <lukem@wasabisystems.com> Subject: Re: [PATCH] add a SITE MD5 command to ftpd Message-ID: <20010317190145.K61859@ohm.physics.purdue.edu>
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--NLszGGfvVP7rUs9N Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi -arch, Luke Mewburn's reply on this issue. Luke, check out the archive here: http://docs.freebsd.org/cgi/mailindex.cgi?sort=3Ddate&file=3Dcurrent/freebs= d-arch I think your issues have probably already been hashed out. So I'll not say any more until you have a look at the archive. Others may comment, though. ----- Forwarded message from Luke Mewburn <lukem@wasabisystems.com> ----- Date: Sun, 18 Mar 2001 10:53:23 +1100 From: Luke Mewburn <lukem@wasabisystems.com> To: Will Andrews <will@physics.purdue.edu> Subject: Re: FW: [PATCH] add a SITE MD5 command to ftpd User-Agent: Mutt/1.2.5i Sender: lukem@limb.com.au On Wed, Mar 14, 2001 at 03:49:19PM -0500, Will Andrews wrote: > What do you think of this? I'm forwarding in case you hadn't heard > about ideas like this. Some discussion that ensued indicated that this > would be an excellent idea for mirroring purposes, among other things. >=20 > Since FreeBSD is considering (and some have been working on patches > towards) simply bringing in lukemftpd into FreeBSD's repository and > using it as its ftpd, it would be nice to hear your opinion on this. I think it's possibly a bit messy :-/. Also, NetBSD itself is moving to newer digests (SHA1, RMD160), and I can see the explosion of problems supporting multiple hashes from that point :/ Also, it's only useful if all the servers support it, and the majority of your distfiles (except those you locally mirror on ftp.freebsd.org) probably won't be on servers that support SITE MD5 anyway. Sorry to seem so negative about the idea. I'm a bit conservative about adding features like this without considering the `cleanest' and best long-term solution. Can you point me at a mail archive discussing this? Maybe my issues will have been covered there already. BTW: I've got a beta version of an auto-conf aware version of ftpd available (aka lukemftpd :). This would allow an up-to-date ftpd to be installed other systems (Solaris, Linux) as well as older NetBSD/FreeBSD releases. I've even got the most recent DoS problem solved in my source. I could make it available for testing to you if you wanted to try it on old FreeBSD releases if you were interested. > ----- Forwarded message from Peter Pentchev <roam@orbitel.bg> ----- >=20 > Date: Tue, 13 Mar 2001 21:15:44 +0200 > From: Peter Pentchev <roam@orbitel.bg> > To: freebsd-arch@FreeBSD.ORG > Subject: [PATCH] add a SITE MD5 command to ftpd > User-Agent: Mutt/1.2.5i > Sender: owner-freebsd-arch@FreeBSD.ORG >=20 > Hi, >=20 > A recent thread about Bill Fenner's distfiles-checking scripts > set me thinking about easy detection of MD5 checksum mismatches. > Bill Fenner pointed out that these checks are not done because > of the sheer volume of the network traffic needed to download > all the distfiles from all the distsites. >=20 > I know that adding a ``SITE MD5 filename'' command to our ftpd > is a *very* little step in a possibly wrong direction (this will > not automagically make all the ftp daemons on all the distsites > implement this command), but IMHO, it's a start.. I'm thinking > of adding similar functionality to wu-ftpd and ProFTPd soon, and > submitting patches to the authors, in the hope of starting a ball > rolling :) >=20 > G'luck, > Peter >=20 > --=20 > because I didn't think of a good beginning of it. >=20 > Index: src/libexec/ftpd/ftpcmd.y > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/libexec/ftpd/ftpcmd.y,v > retrieving revision 1.21 > diff -u -r1.21 ftpcmd.y > --- src/libexec/ftpd/ftpcmd.y 2001/02/19 21:51:26 1.21 > +++ src/libexec/ftpd/ftpcmd.y 2001/03/13 18:48:54 > @@ -58,6 +58,7 @@ > #include <ctype.h> > #include <errno.h> > #include <glob.h> > +#include <md5.h> > #include <netdb.h> > #include <pwd.h> > #include <setjmp.h> > @@ -92,6 +93,7 @@ > extern char tmpline[]; > extern int readonly; > extern int noepsv; > +extern int nomd5; > =20 > off_t restart_point; > =20 > @@ -126,7 +128,7 @@ > CDUP STOU SMNT SYST SIZE MDTM > LPRT LPSV EPRT EPSV > =20 > - UMASK IDLE CHMOD > + UMASK IDLE CHMOD MD5 > =20 > LEXERR > =20 > @@ -648,6 +650,34 @@ > } > } > } > + | SITE SP check_login MD5 SP pathname CRLF > + { > + if ($3) { > + struct stat stbuf; > + char hash[33]; > + > + if (nomd5) > + reply(500, > + "SITE MD5 command disabled", > + $6); > + else if (stat($6, &stbuf) < 0) > + reply(550, > + "%s: %s", > + $6, strerror(errno)); > + else if (!S_ISREG(stbuf.st_mode)) > + reply(550, > + "%s: not a plain file", > + $6); > + else if (MD5File($6, hash) =3D=3D NULL) > + reply(550, > + "%s: %s", > + $6, strerror(errno)); > + else > + reply(200, > + "MD5 %s %s", > + hash, $6); > + } > + } > | STOU check_login_ro SP pathname CRLF > { > if ($2 && $4 !=3D NULL) > @@ -1088,6 +1118,7 @@ > { "IDLE", IDLE, ARGS, 1, "[ <sp> maximum-idle-time ]" }, > { "CHMOD", CHMOD, NSTR, 1, "<sp> mode <sp> file-name" }, > { "HELP", HELP, OSTR, 1, "[ <sp> <string> ]" }, > + { "MD5", MD5, STR1, 1, "<sp> file-name" }, > { NULL, 0, 0, 0, 0 } > }; > =20 > Index: src/libexec/ftpd/ftpd.8 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/libexec/ftpd/ftpd.8,v > retrieving revision 1.36 > diff -u -r1.36 ftpd.8 > --- src/libexec/ftpd/ftpd.8 2000/12/18 08:33:25 1.36 > +++ src/libexec/ftpd/ftpd.8 2001/03/13 18:48:54 > @@ -42,6 +42,7 @@ > .Sh SYNOPSIS > .Nm > .Op Fl 4 > +.Op Fl 5 > .Op Fl 6 > .Op Fl d > .Op Fl l Op Fl l > @@ -153,6 +154,10 @@ > When > .Fl 6 > is not specified, accept IPv4 connection via AF_INET socket. > +.It Fl 5 > +Disable the SITE MD5 command. > +This is useful for preventing possible denial of service attacks, > +especially on servers allowing anonymous ftp access. > .It Fl A > Allow only anonymous ftp access. > .It Fl r > Index: src/libexec/ftpd/ftpd.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/libexec/ftpd/ftpd.c,v > retrieving revision 1.73 > diff -u -r1.73 ftpd.c > --- src/libexec/ftpd/ftpd.c 2001/03/11 13:20:44 1.73 > +++ src/libexec/ftpd/ftpd.c 2001/03/13 18:48:56 > @@ -150,6 +150,7 @@ > int pdata =3D -1; /* for passive mode */ > int readonly=3D0; /* Server is in readonly mode. */ > int noepsv=3D0; /* EPSV command is disabled. */ > +int nomd5=3D0; /* SITE MD5 command is disabled. */ > sig_atomic_t transflag; > off_t file_size; > off_t byte_count; > @@ -292,7 +293,7 @@ > #endif /* OLD_SETPROCTITLE */ > =20 > =20 > - while ((ch =3D getopt(argc, argv, "AdlDESURrt:T:u:va:p:46")) !=3D -1) { > + while ((ch =3D getopt(argc, argv, "AdlDESURrt:T:u:va:p:456")) !=3D -1) { > switch (ch) { > case 'D': > daemon_mode++; > @@ -369,6 +370,10 @@ > enable_v4 =3D 1; > if (family =3D=3D AF_UNSPEC) > family =3D AF_INET; > + break; > + > + case '5': > + nomd5 =3D 1; > break; > =20 > case '6': >=20 > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-arch" in the body of the message >=20 > ----- End forwarded message ----- >=20 > --=20 > wca --=20 Luke Mewburn <lukem@wasabisystems.com> http://www.wasabisystems.com Luke Mewburn <lukem@netbsd.org> http://www.netbsd.org Wasabi Systems - providing NetBSD sales, support and service. ----- End forwarded message ----- --=20 wca --NLszGGfvVP7rUs9N Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.3 (FreeBSD) Comment: For info see http://www.gnupg.org iD8DBQE6s/rpF47idPgWcsURAq36AKCFfiLIv48V0+CtJhjauEvJqmgS8gCfY7Du myKxnMEwbDe9+S4CG4r+jnM= =VbYw -----END PGP SIGNATURE----- --NLszGGfvVP7rUs9N-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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