From: Brian Warner Date: Thu, 6 Nov 2008 02:25:58 +0000 (-0700) Subject: SFTP/FTP: merge user/account code, merge docs X-Git-Url: https://git.rkrishnan.org/%5B/%5D%20/uri/%22doc.html/architecture.txt?a=commitdiff_plain;h=7c4856c222ecd16702dfdf16e9ebdd31ebc9416a;p=tahoe-lafs%2Ftahoe-lafs.git SFTP/FTP: merge user/account code, merge docs --- diff --git a/docs/frontends/FTP-and-SFTP.txt b/docs/frontends/FTP-and-SFTP.txt new file mode 100644 index 00000000..0c44cde7 --- /dev/null +++ b/docs/frontends/FTP-and-SFTP.txt @@ -0,0 +1,213 @@ += Tahoe FTP/SFTP Frontend = + +== FTP/SFTP Background == + +FTP is the venerable internet file-transfer protocol, first developed in +1971. The FTP server usually listens on port 21. A separate connection is +used for the actual data transfers, either in the same direction as the +initial client-to-server connection (for PORT mode), or in the reverse +direction (for PASV) mode. Connections are unencrypted, so passwords, file +names, and file contents are visible to eavesdroppers. + +SFTP is the modern replacement, developed as part of the SSH "secure shell" +protocol, and runs as a subchannel of the regular SSH connection. The SSH +server usually listens on port 22. All connections are encrypted. + +Both FTP and SFTP were developed assuming a UNIX-like server, with accounts +and passwords, octal file modes (user/group/other, read/write/execute), and +ctime/mtime timestamps. + +== Tahoe Support == + +All Tahoe client nodes can run a frontend FTP server, allowing regular FTP +clients (like /usr/bin/ftp, ncftp, and countless others) to access the +virtual filesystem. They can also run an SFTP server, so SFTP clients (like +/usr/bin/sftp, the sshfs FUSE plugin, and others) can too. These frontends +sit at the same level as the webapi interface. + +Since Tahoe does not use user accounts or passwords, the FTP/SFTP servers +must be configured with a way to first authenticate a user (confirm that a +prospective client has a legitimate claim to whatever authorities we might +grant a particular user), and second to decide what root directory cap should +be granted to the authenticated username. FTP uses a username and password +for this purpose. SFTP can either use a username and password, or a username +and an RSA or DSA public key (SSH servers are frequently configured to +require public key logins and reject passwords, to remove the threat of +password-guessing attacks, at the expense of requiring users to carry their +private keys around with them). + +Tahoe provides two mechanisms to perform this user-to-rootcap mapping. The +first is a simple flat file with one account per line. The second is an +HTTP-based login mechanism, backed by simple PHP script and a database. The +latter form is used by allmydata.com to provide secure access to customer +rootcaps. + +== Creating an Account File == + +To use the first form, create a file (probably in +BASEDIR/private/ftp.accounts) in which each non-comment/non-blank line is a +space-separated line of (USERNAME, PASSWORD/PUBKEY, ROOTCAP), like so: + + % cat BASEDIR/private/ftp.accounts + # This is a password line, (username, password, rootcap) + alice password URI:DIR2:ioej8xmzrwilg772gzj4fhdg7a:wtiizszzz2rgmczv4wl6bqvbv33ag4kvbr6prz3u6w3geixa6m6a + bob sekrit URI:DIR2:6bdmeitystckbl9yqlw7g56f4e:serp5ioqxnh34mlbmzwvkp3odehsyrr7eytt5f64we3k9hhcrcja + + # and this is a public key line (username, pubkey, rootcap) + carol ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAv2xHRVBoXnwxHLzthRD1wOWtyZ08b8n9cMZfJ58CBdBwAYP2NVNXc0XjRvswm5hnnAO+jyWPVNpXJjm9XllzYhODSNtSN+TXuJlUjhzA/T+ZwdgsgSAeHuuMQBoWt4Qc9HV6rHCdAeMhcnyqm6Q0sRAsfA/wfwiIgbvE7+cWpFa2anB6WeAnvK8+dMN0nvnkPE7GNyf/WFR1Ffuh9ifKdRB6yDNp17bQAqA3OWSFjch6fGPhp94y4g2jmTHlEUTyVsilgGqvGOutOVYnmOMnFijugU1Vu33G39GGzXWla6+fXwTk/oiVPiCYD7A7WFKes3nqMg8iVN6a6sxujrhnHQ== warner@fluxx URI:DIR2:6bdmeitystckbl9yqlw7g56f4e:serp5ioqxnh34mlbmzwvkp3odehsyrr7eytt5f64we3k9hhcrcja + +[TODO: the PUBKEY form is not yet supported] + +Note that if the second word of the line is "ssh-rsa" or "ssh-dss", the rest +of the line is parsed differently, so users cannot have a password equal to +either of these strings. + +Then add an 'accounts.file' directive to your tahoe.cfg file, as described +in the next sections. + +== Configuring FTP Access == + +To enable the FTP server with an accounts file, add the following lines to +the BASEDIR/tahoe.cfg file: + + [ftpd] + enabled = true + port = 8021 + accounts.file = private/ftp.accounts + +The FTP server will listen on the given port number. The "accounts.file" +pathname will be interpreted relative to the node's BASEDIR. + +To enable the FTP server with an account server instead, provide the URL of +that server in an "accounts.url" directive: + + [ftpd] + enabled = true + port = 8021 + accounts.url = https://example.com/login + +You can provide both accounts.file and accounts.url, although it probably +isn't very useful except for testing. + +== Configuring SFTP Access == + +The Tahoe SFTP server requires a host keypair, just like the regular SSH +server. It is important to give each server a distinct keypair, to prevent +one server from masquerading as different one. The first time a client +program talks to a given server, it will store the host key it receives, and +will complain if a subsequent connection uses a different key. This reduces +the opportunity for man-in-the-middle attacks to just the first connection. + +You will use directives in the tahoe.cfg file to tell the SFTP code where to +find these keys. To create one, use the ssh-keygen tool (which comes with the +normal openssl client distribution): + +% cd BASEDIR +% ssh-keygen -f private/ssh_host_rsa_key + +Then, to enable the SFTP server with an accounts file, add the following +lines to the BASEDIR/tahoe.cfg file: + + [sftpd] + enabled = true + port = 8022 + host_pubkey_file = private/ssh_host_rsa_key.pub + host_privkey_file = private/ssh_host_rsa_key + accounts.file = private/ftp.accounts + +The SFTP server will listen on the given port number. The "accounts.file" +pathname will be interpreted relative to the node's BASEDIR. + +Or, to use an account server instead, do this: + + [sftpd] + enabled = true + port = 8022 + host_pubkey_file = private/ssh_host_rsa_key.pub + host_privkey_file = private/ssh_host_rsa_key + accounts.url = https://example.com/login + +You can provide both accounts.file and accounts.url, although it probably +isn't very useful except for testing. + + +== Dependencies == + +The Tahoe SFTP server requires the Twisted "Conch" component (a "conch" is a +twisted shell, get it?). Many Linux distributions package the Conch code +separately: debian puts it in the "python-twisted-conch" package. Conch +requires the "pycrypto" package, which is a Python+C implementation of many +cryptographic functions (the debian package is named "python-crypto"). + +Note that "pycrypto" is different than the "pycryptopp" package that Tahoe +uses (which is a Python wrapper around the C++ -based Crypto++ library, a +library that is frequently installed as /usr/lib/libcryptopp.a, to avoid +problems with non-alphanumerics in filenames). + +The FTP server requires code in Twisted that enables asynchronous closing of +file-upload operations. This code was not in the Twisted-8.1.0 release, and +has not been committed to SVN trunk as of r24943. So it may be necessary to +apply the following patch. The Tahoe node refuse to start the FTP server if +it detects that this patch has not been applied. + +Index: twisted/protocols/ftp.py +=================================================================== +--- twisted/protocols/ftp.py (revision 24956) ++++ twisted/protocols/ftp.py (working copy) +@@ -1049,7 +1049,6 @@ + cons = ASCIIConsumerWrapper(cons) + + d = self.dtpInstance.registerConsumer(cons) +- d.addCallbacks(cbSent, ebSent) + + # Tell them what to doooo + if self.dtpInstance.isConnected: +@@ -1062,6 +1061,8 @@ + def cbOpened(file): + d = file.receive() + d.addCallback(cbConsumer) ++ d.addCallback(lambda ignored: file.close()) ++ d.addCallbacks(cbSent, ebSent) + return d + + def ebOpened(err): +@@ -1434,7 +1435,14 @@ + @rtype: C{Deferred} of C{IConsumer} + """ + ++ def close(): ++ """ ++ Perform any post-write work that needs to be done. This method may ++ only be invoked once on each provider, and will always be invoked ++ after receive(). + ++ @rtype: C{Deferred} of anything: the value is ignored ++ """ + + def _getgroups(uid): + """Return the primary and supplementary groups for the given UID. +@@ -1795,6 +1803,8 @@ + # FileConsumer will close the file object + return defer.succeed(FileConsumer(self.fObj)) + ++ def close(self): ++ return defer.succeed(None) + + + class FTPRealm: +Index: twisted/vfs/adapters/ftp.py +=================================================================== +--- twisted/vfs/adapters/ftp.py (revision 24956) ++++ twisted/vfs/adapters/ftp.py (working copy) +@@ -295,6 +295,11 @@ + """ + return defer.succeed(IConsumer(self.node)) + ++ def close(self): ++ """ ++ Perform post-write actions. ++ """ ++ return defer.succeed(None) + + + class _FileToConsumerAdapter(object): diff --git a/docs/frontends/ftp.txt b/docs/frontends/ftp.txt deleted file mode 100644 index 50774c6e..00000000 --- a/docs/frontends/ftp.txt +++ /dev/null @@ -1,112 +0,0 @@ -= Tahoe FTP Frontend = - -All Tahoe client nodes can run a frontend FTP server, allowing regular FTP -clients to access the virtual filesystem. - -Since Tahoe does not use user accounts or passwords, the FTP server must be -configured with a way to translate USER+PASS into a root directory cap. Two -mechanisms are provided. The first is a simple flat file with one account per -line. The second is an HTTP-based login mechanism, backed by simple PHP -script and a database. The latter form is used by allmydata.com to provide -secure access to customer rootcaps. - -== Configuring an Account File == - -To configure the first form, create a file (probably in -BASEDIR/private/ftp.accounts) in which each non-comment/non-blank line is a -space-separated line of (USERNAME, PASSWORD, ROOTCAP), like so: - - % cat BASEDIR/private/ftp.accounts - # This is a password file, (username, password, rootcap) - alice password URI:DIR2:ioej8xmzrwilg772gzj4fhdg7a:wtiizszzz2rgmczv4wl6bqvbv33ag4kvbr6prz3u6w3geixa6m6a - bob sekrit URI:DIR2:6bdmeitystckbl9yqlw7g56f4e:serp5ioqxnh34mlbmzwvkp3odehsyrr7eytt5f64we3k9hhcrcja - -Then add the following lines to the BASEDIR/tahoe.cfg file: - - [ftpd] - enabled = true - ftp.port = 8021 - ftp.accounts.file = private/ftp.accounts - -The FTP server will listen on the given port number. The ftp.accounts.file -pathname will be interpreted relative to the node's BASEDIR. - -== Configuring an Account Server == - -Determine the URL of the account server, say https://example.com/login . Then -add the following lines to BASEDIR/tahoe.cfg: - - [ftpd] - enabled = true - ftp.port = 8021 - ftp.accounts.url = https://example.com/login - -== Dependencies == - -The FTP server requires code in Twisted that enables asynchronous closing of -file-upload operations. This code was not in the Twisted-8.1.0 release, and -has not been committed to SVN trunk as of r24943. So it may be necessary to -apply the following patch. The Tahoe node refuse to start the FTP server if -it detects that this patch has not been applied. - -Index: twisted/protocols/ftp.py -=================================================================== ---- twisted/protocols/ftp.py (revision 24956) -+++ twisted/protocols/ftp.py (working copy) -@@ -1049,7 +1049,6 @@ - cons = ASCIIConsumerWrapper(cons) - - d = self.dtpInstance.registerConsumer(cons) -- d.addCallbacks(cbSent, ebSent) - - # Tell them what to doooo - if self.dtpInstance.isConnected: -@@ -1062,6 +1061,8 @@ - def cbOpened(file): - d = file.receive() - d.addCallback(cbConsumer) -+ d.addCallback(lambda ignored: file.close()) -+ d.addCallbacks(cbSent, ebSent) - return d - - def ebOpened(err): -@@ -1434,7 +1435,14 @@ - @rtype: C{Deferred} of C{IConsumer} - """ - -+ def close(): -+ """ -+ Perform any post-write work that needs to be done. This method may -+ only be invoked once on each provider, and will always be invoked -+ after receive(). - -+ @rtype: C{Deferred} of anything: the value is ignored -+ """ - - def _getgroups(uid): - """Return the primary and supplementary groups for the given UID. -@@ -1795,6 +1803,8 @@ - # FileConsumer will close the file object - return defer.succeed(FileConsumer(self.fObj)) - -+ def close(self): -+ return defer.succeed(None) - - - class FTPRealm: -Index: twisted/vfs/adapters/ftp.py -=================================================================== ---- twisted/vfs/adapters/ftp.py (revision 24956) -+++ twisted/vfs/adapters/ftp.py (working copy) -@@ -295,6 +295,11 @@ - """ - return defer.succeed(IConsumer(self.node)) - -+ def close(self): -+ """ -+ Perform post-write actions. -+ """ -+ return defer.succeed(None) - - - class _FileToConsumerAdapter(object): diff --git a/docs/frontends/sftp.txt b/docs/frontends/sftp.txt deleted file mode 100644 index cb085823..00000000 --- a/docs/frontends/sftp.txt +++ /dev/null @@ -1,74 +0,0 @@ -= Tahoe SFTP Frontend = - -All Tahoe client nodes can run a frontend SFTP server, allowing regular SFTP -clients to access the virtual filesystem. - -Since Tahoe does not use user accounts or passwords, the FTP server must be -configured with a way to translate a username (and either a password or -public key) into a root directory cap. Two mechanisms are provided. The first -is a simple flat file with one account per line. The second is an HTTP-based -login mechanism, backed by simple PHP script and a database. The latter form -is used by allmydata.com to provide secure access to customer rootcaps. - -The SFTP server must also be given a public/private host keypair. - -== Configuring a Keypair == - -First, generate a keypair for your server: - -% cd BASEDIR -% ssh-keygen -f private/ssh_host_rsa_key - -You will then use the following lines in the tahoe.cfg file: - - [sftpd] - sftp.host_pubkey_file = private/ssh_host_rsa_key.pub - sftp.host_privkey_file = private/ssh_host_rsa_key - -== Configuring an Account File == - -To configure the first form, create a file (probably in -BASEDIR/private/sftp.accounts) in which each non-comment/non-blank line is a -space-separated line of (USERNAME, PASSWORD/PUBKEY, ROOTCAP), like so: - -[TODO: the PUBKEY form is not yet supported] - - % cat BASEDIR/private/sftp.accounts - # This is a password file, (username, password/pubkey, rootcap) - alice password URI:DIR2:ioej8xmzrwilg772gzj4fhdg7a:wtiizszzz2rgmczv4wl6bqvbv33ag4kvbr6prz3u6w3geixa6m6a - bob sekrit URI:DIR2:6bdmeitystckbl9yqlw7g56f4e:serp5ioqxnh34mlbmzwvkp3odehsyrr7eytt5f64we3k9hhcrcja - carol ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAv2xHRVBoXnwxHLzthRD1wOWtyZ08b8n9cMZfJ58CBdBwAYP2NVNXc0XjRvswm5hnnAO+jyWPVNpXJjm9XllzYhODSNtSN+TXuJlUjhzA/T+ZwdgsgSAeHuuMQBoWt4Qc9HV6rHCdAeMhcnyqm6Q0sRAsfA/wfwiIgbvE7+cWpFa2anB6WeAnvK8+dMN0nvnkPE7GNyf/WFR1Ffuh9ifKdRB6yDNp17bQAqA3OWSFjch6fGPhp94y4g2jmTHlEUTyVsilgGqvGOutOVYnmOMnFijugU1Vu33G39GGzXWla6+fXwTk/oiVPiCYD7A7WFKes3nqMg8iVN6a6sxujrhnHQ== warner@fluxx URI:DIR2:6bdmeitystckbl9yqlw7g56f4e:serp5ioqxnh34mlbmzwvkp3odehsyrr7eytt5f64we3k9hhcrcja - -Note that if the second word of the line is "ssh-rsa" or "ssh-dss", the rest -of the line is parsed differently, so users cannot have a password equal to -either of these strings. - -Then add the following lines to the BASEDIR/tahoe.cfg file: - - [sftpd] - enabled = true - sftp.port = 8022 - sftp.host_pubkey_file = private/ssh_host_rsa_key.pub - sftp.host_privkey_file = private/ssh_host_rsa_key - sftp.accounts.file = private/sftp.accounts - -The SFTP server will listen on the given port number. The sftp.accounts.file -pathname will be interpreted relative to the node's BASEDIR. - -== Configuring an Account Server == - -Determine the URL of the account server, say https://example.com/login . Then -add the following lines to BASEDIR/tahoe.cfg: - - [sftpd] - enabled = true - sftp.port = 8022 - sftp.host_pubkey_file = private/ssh_host_rsa_key.pub - sftp.host_privkey_file = private/ssh_host_rsa_key - sftp.accounts.url = https://example.com/login - -== Dependencies == - -The Tahoe SFTP server requires the Twisted "Conch" component, which itself -requires the pycrypto package (note that pycrypto is distinct from the -pycryptopp that Tahoe uses). diff --git a/src/allmydata/frontends/auth.py b/src/allmydata/frontends/auth.py new file mode 100644 index 00000000..6adbebb2 --- /dev/null +++ b/src/allmydata/frontends/auth.py @@ -0,0 +1,98 @@ +import os +from zope.interface import implements +from twisted.web.client import getPage +from twisted.internet import defer +from twisted.cred import error, checkers, credentials +from allmydata.util import base32 + +class FTPAvatarID: + def __init__(self, username, rootcap): + self.username = username + self.rootcap = rootcap + +class AccountFileChecker: + implements(checkers.ICredentialsChecker) + credentialInterfaces = (credentials.IUsernamePassword, + credentials.IUsernameHashedPassword) + def __init__(self, client, accountfile): + self.client = client + self.passwords = {} + self.pubkeys = {} + self.rootcaps = {} + for line in open(os.path.expanduser(accountfile), "r"): + line = line.strip() + if line.startswith("#") or not line: + continue + name, passwd, rest = line.split(None, 2) + if passwd in ("ssh-dss", "ssh-rsa"): + bits = rest.split() + keystring = " ".join(bits[-1]) + rootcap = bits[-1] + self.pubkeys[name] = keystring + else: + self.passwords[name] = passwd + rootcap = rest + self.rootcaps[name] = rootcap + + def _cbPasswordMatch(self, matched, username): + if matched: + return FTPAvatarID(username, self.rootcaps[username]) + raise error.UnauthorizedLogin + + def requestAvatarId(self, credentials): + if credentials.username in self.passwords: + d = defer.maybeDeferred(credentials.checkPassword, + self.passwords[credentials.username]) + d.addCallback(self._cbPasswordMatch, str(credentials.username)) + return d + return defer.fail(error.UnauthorizedLogin()) + +class AccountURLChecker: + implements(checkers.ICredentialsChecker) + credentialInterfaces = (credentials.IUsernamePassword,) + + def __init__(self, client, auth_url): + self.client = client + self.auth_url = auth_url + + def _cbPasswordMatch(self, rootcap, username): + return FTPAvatarID(username, rootcap) + + def post_form(self, username, password): + sepbase = base32.b2a(os.urandom(4)) + sep = "--" + sepbase + form = [] + form.append(sep) + fields = {"action": "authenticate", + "email": username, + "passwd": password, + } + for name, value in fields.iteritems(): + form.append('Content-Disposition: form-data; name="%s"' % name) + form.append('') + assert isinstance(value, str) + form.append(value) + form.append(sep) + form[-1] += "--" + body = "\r\n".join(form) + "\r\n" + headers = {"content-type": "multipart/form-data; boundary=%s" % sepbase, + } + return getPage(self.auth_url, method="POST", + postdata=body, headers=headers, + followRedirect=True, timeout=30) + + def _parse_response(self, res): + rootcap = res.strip() + if rootcap == "0": + raise error.UnauthorizedLogin + return rootcap + + def requestAvatarId(self, credentials): + # construct a POST to the login form. While this could theoretically + # be done with something like the stdlib 'email' package, I can't + # figure out how, so we just slam together a form manually. + d = self.post_form(credentials.username, credentials.password) + d.addCallback(self._parse_response) + d.addCallback(self._cbPasswordMatch, str(credentials.username)) + return d + diff --git a/src/allmydata/frontends/ftpd.py b/src/allmydata/frontends/ftpd.py index 5ade0e20..598c8db0 100644 --- a/src/allmydata/frontends/ftpd.py +++ b/src/allmydata/frontends/ftpd.py @@ -1,19 +1,16 @@ -import os import tempfile from zope.interface import implements from twisted.application import service, strports from twisted.internet import defer from twisted.internet.interfaces import IConsumer +from twisted.cred import portal from twisted.protocols import ftp -from twisted.cred import error, portal, checkers, credentials -from twisted.web.client import getPage from allmydata.interfaces import IDirectoryNode, ExistingChildError, \ NoSuchChildError from allmydata.immutable.download import ConsumerAdapter from allmydata.immutable.upload import FileHandle -from allmydata.util import base32 class ReadFile: implements(ftp.IReadFile) @@ -270,89 +267,7 @@ class Handler: d.addCallback(_got_parent) return d - -class FTPAvatarID: - def __init__(self, username, rootcap): - self.username = username - self.rootcap = rootcap - -class AccountFileChecker: - implements(checkers.ICredentialsChecker) - credentialInterfaces = (credentials.IUsernamePassword, - credentials.IUsernameHashedPassword) - def __init__(self, client, accountfile): - self.client = client - self.passwords = {} - self.rootcaps = {} - for line in open(os.path.expanduser(accountfile), "r"): - line = line.strip() - if line.startswith("#") or not line: - continue - name, passwd, rootcap = line.split() - self.passwords[name] = passwd - self.rootcaps[name] = rootcap - - def _cbPasswordMatch(self, matched, username): - if matched: - return FTPAvatarID(username, self.rootcaps[username]) - raise error.UnauthorizedLogin - - def requestAvatarId(self, credentials): - if credentials.username in self.passwords: - d = defer.maybeDeferred(credentials.checkPassword, - self.passwords[credentials.username]) - d.addCallback(self._cbPasswordMatch, str(credentials.username)) - return d - return defer.fail(error.UnauthorizedLogin()) - -class AccountURLChecker: - implements(checkers.ICredentialsChecker) - credentialInterfaces = (credentials.IUsernamePassword,) - - def __init__(self, client, auth_url): - self.client = client - self.auth_url = auth_url - - def _cbPasswordMatch(self, rootcap, username): - return FTPAvatarID(username, rootcap) - - def post_form(self, username, password): - sepbase = base32.b2a(os.urandom(4)) - sep = "--" + sepbase - form = [] - form.append(sep) - fields = {"action": "authenticate", - "email": username, - "passwd": password, - } - for name, value in fields.iteritems(): - form.append('Content-Disposition: form-data; name="%s"' % name) - form.append('') - assert isinstance(value, str) - form.append(value) - form.append(sep) - form[-1] += "--" - body = "\r\n".join(form) + "\r\n" - headers = {"content-type": "multipart/form-data; boundary=%s" % sepbase, - } - return getPage(self.auth_url, method="POST", - postdata=body, headers=headers, - followRedirect=True, timeout=30) - - def _parse_response(self, res): - rootcap = res.strip() - if rootcap == "0": - raise error.UnauthorizedLogin - return rootcap - - def requestAvatarId(self, credentials): - # construct a POST to the login form. While this could theoretically - # be done with something like the stdlib 'email' package, I can't - # figure out how, so we just slam together a form manually. - d = self.post_form(credentials.username, credentials.password) - d.addCallback(self._parse_response) - d.addCallback(self._cbPasswordMatch, str(credentials.username)) - return d +from auth import AccountURLChecker, AccountFileChecker class Dispatcher: @@ -373,22 +288,23 @@ class FTPServer(service.MultiService): def __init__(self, client, accountfile, accounturl, ftp_portstr): service.MultiService.__init__(self) + # make sure we're using a patched Twisted that uses IWriteFile.close: + # see docs/frontends/ftp.txt for details. + assert "close" in ftp.IWriteFile.names(), "your twisted is lacking" + + r = Dispatcher(client) + p = portal.Portal(r) + if accountfile: c = AccountFileChecker(self, accountfile) - elif accounturl: + p.registerChecker(c) + if accounturl: c = AccountURLChecker(self, accounturl) - else: + p.registerChecker(c) + if not accountfile and not accounturl: # we could leave this anonymous, with just the /uri/CAP form raise RuntimeError("must provide some translation") - # make sure we're using a patched Twisted that uses IWriteFile.close: - # see docs/ftp.txt for details. - assert "close" in ftp.IWriteFile.names(), "your twisted is lacking" - - r = Dispatcher(client) - p = portal.Portal(r) - p.registerChecker(c) f = ftp.FTPFactory(p) - s = strports.service(ftp_portstr, f) s.setServiceParent(self) diff --git a/src/allmydata/frontends/sftpd.py b/src/allmydata/frontends/sftpd.py index 790e5d7e..d29aa8a6 100644 --- a/src/allmydata/frontends/sftpd.py +++ b/src/allmydata/frontends/sftpd.py @@ -1,5 +1,4 @@ -import os import tempfile from zope.interface import implements from twisted.python import components @@ -11,13 +10,11 @@ from twisted.conch.interfaces import ISFTPServer, ISFTPFile, IConchUser from twisted.conch.avatar import ConchUser from twisted.conch.openssh_compat import primes from twisted.conch import ls -from twisted.cred import error, portal, checkers, credentials -from twisted.web.client import getPage +from twisted.cred import portal from allmydata.interfaces import IDirectoryNode, ExistingChildError, \ NoSuchChildError from allmydata.immutable.upload import FileHandle -from allmydata.util import base32 class MemoryConsumer: implements(IConsumer) @@ -420,101 +417,12 @@ class SFTPHandler: return d -class FTPAvatarID: - def __init__(self, username, rootcap): - self.username = username - self.rootcap = rootcap - -class AccountFileChecker: - implements(checkers.ICredentialsChecker) - credentialInterfaces = (credentials.IUsernamePassword, - credentials.IUsernameHashedPassword) - def __init__(self, client, accountfile): - self.client = client - self.passwords = {} - self.pubkeys = {} - self.rootcaps = {} - for line in open(os.path.expanduser(accountfile), "r"): - line = line.strip() - if line.startswith("#") or not line: - continue - name, passwd, rest = line.split(None, 2) - if passwd in ("ssh-dss", "ssh-rsa"): - bits = rest.split() - keystring = " ".join(bits[-1]) - rootcap = bits[-1] - self.pubkeys[name] = keystring - else: - self.passwords[name] = passwd - rootcap = rest - self.rootcaps[name] = rootcap - - def _cbPasswordMatch(self, matched, username): - if matched: - return FTPAvatarID(username, self.rootcaps[username]) - raise error.UnauthorizedLogin - - def requestAvatarId(self, credentials): - if credentials.username in self.passwords: - d = defer.maybeDeferred(credentials.checkPassword, - self.passwords[credentials.username]) - d.addCallback(self._cbPasswordMatch, str(credentials.username)) - return d - return defer.fail(error.UnauthorizedLogin()) - -class AccountURLChecker: - implements(checkers.ICredentialsChecker) - credentialInterfaces = (credentials.IUsernamePassword,) - - def __init__(self, client, auth_url): - self.client = client - self.auth_url = auth_url - - def _cbPasswordMatch(self, rootcap, username): - return FTPAvatarID(username, rootcap) - - def post_form(self, username, password): - sepbase = base32.b2a(os.urandom(4)) - sep = "--" + sepbase - form = [] - form.append(sep) - fields = {"action": "authenticate", - "email": username, - "passwd": password, - } - for name, value in fields.iteritems(): - form.append('Content-Disposition: form-data; name="%s"' % name) - form.append('') - assert isinstance(value, str) - form.append(value) - form.append(sep) - form[-1] += "--" - body = "\r\n".join(form) + "\r\n" - headers = {"content-type": "multipart/form-data; boundary=%s" % sepbase, - } - return getPage(self.auth_url, method="POST", - postdata=body, headers=headers, - followRedirect=True, timeout=30) - - def _parse_response(self, res): - rootcap = res.strip() - if rootcap == "0": - raise error.UnauthorizedLogin - return rootcap - - def requestAvatarId(self, credentials): - # construct a POST to the login form. While this could theoretically - # be done with something like the stdlib 'email' package, I can't - # figure out how, so we just slam together a form manually. - d = self.post_form(credentials.username, credentials.password) - d.addCallback(self._parse_response) - d.addCallback(self._cbPasswordMatch, str(credentials.username)) - return d - # if you have an SFTPUser, and you want something that provides ISFTPServer, # then you get SFTPHandler(user) components.registerAdapter(SFTPHandler, SFTPUser, ISFTPServer) +from auth import AccountURLChecker, AccountFileChecker + class Dispatcher: implements(portal.IRealm) def __init__(self, client): @@ -533,18 +441,19 @@ class SFTPServer(service.MultiService): sftp_portstr, pubkey_file, privkey_file): service.MultiService.__init__(self) + r = Dispatcher(client) + p = portal.Portal(r) + if accountfile: c = AccountFileChecker(self, accountfile) - elif accounturl: + p.registerChecker(c) + if accounturl: c = AccountURLChecker(self, accounturl) - else: + p.registerChecker(c) + if not accountfile and not accounturl: # we could leave this anonymous, with just the /uri/CAP form raise RuntimeError("must provide some translation") - r = Dispatcher(client) - p = portal.Portal(r) - p.registerChecker(c) - pubkey = keys.Key.fromFile(pubkey_file) privkey = keys.Key.fromFile(privkey_file) class SSHFactory(factory.SSHFactory):