3 .\" Author: Jean-Louis Martineau <martineau@zmanda.com>
4 .\" Generator: DocBook XSL Stylesheets vsnapshot_8273 <http://docbook.sf.net/>
6 .\" Manual: Miscellanea
7 .\" Source: Amanda 3.2.0
10 .TH "AMANDA\-AUTH" "7" "10/18/2010" "Amanda 3\&.2\&.0" "Miscellanea"
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12 .\" * set default formatting
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14 .\" disable hyphenation
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19 .\" * MAIN CONTENT STARTS HERE *
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22 amanda-auth \- Communication/Authentication methods between Amanda server and client
25 Amanda offers 7 methods of communication between Amanda server (sometimes also called the tape server) and clients, each with its own authentication method\&. The desired communication method is specified by the
27 parameter in the amanda\&.conf file (\fBamanda.conf\fR(5)) commonly as a dumptype\&. Valid values to the
36 \fBssh\fR\&. The authentication and communication method is used during the backup process
38 (amdump(8)) as well as the recovery process
41 .SH "COMPILATION AND GENERAL INFORMATION"
43 The communication method and thus type of authentication that will be used by the Amanda server is specified by the
45 parameter in the dumptype for each disklist entry (DLE)\&. The
47 parameter thus may be easily and globally specified in the "global" dumptype\&. If
51 communication method is used\&. See
53 for more information on Amanda configuration and dumptypes, and
55 for more information on disklists\&.
57 On the client side, the Amanda daemon
59 validates the connection depending on the value of the
61 argument passed to it (see Amanda(8))\&. Also, when it comes to recovery, the
63 parameter can be specified in the
64 \fBamanda-client.conf\fR(5)
65 file to specify the communication method to be used by the client to the server\&.
67 When Amanda is being built from source code, desired communication and thus authentication methods (shown as "Authentication") must be specified as configure options at compilation time\&.
70 Authentication Configure option(s)
71 bsd \-\-with\-bsd\-security \-\-with\-amandahosts (pre\-2\&.6)
72 bsdtcp \-\-with\-bsdtcp\-security \-\-with\-amandahosts (pre\-2\&.6)
73 bsdudp \-\-with\-bsdudp\-security \-\-with\-amandahosts (pre\-2\&.6)
74 krb5 \-\-with\-krb5\-security
75 local (always included)
76 rsh \-\-with\-rsh\-security
77 ssh \-\-with\-ssh\-security
80 There are additional configure options for
84 to allow for specifying explicit UDP and TCP port ranges\&.
87 \-\-with\-udpportrange
88 \-\-with\-tcpportrange
89 \-\-with\-low\-tcpportrange
94 below for more information\&.
96 There are additional configure options for Kerberos if you so desire\&. All but the last option are for Kerberos 4\&. Defaults shown in square brackets\&.
99 \-\-with\-server\-principal=ARG server host principal [amanda]
100 \-\-with\-server\-instance=ARG server host instance []
101 \-\-with\-server\-keyfile=ARG server host key file [/\&.amanda]
102 \-\-with\-client\-principal=ARG client host principal [rcmd]
103 \-\-with\-client\-instance=ARG client host instance [HOSTNAME_INSTANCE]
104 \-\-with\-client\-keyfile=ARG client host key file [KEYFILE]
105 \-\-with\-ticket\-lifetime=ARG ticket lifetime [128]
106 \-\-with\-krb5\-security=DIR where libkrb\&.a lives [see below]
109 If configuring with \-\-with\-krb5\-security, the configure script will search under /usr/kerberos/lib, /usr/cygnus/lib, /usr/lib, and /opt/kerberos/lib for the kerberos bits, libkrb\&.a, in this order\&. Kerberos support will not be added if it does not find them\&. If the kerberos bits are found under some other hierarchy, you can specify this via \-\-with\-krb5\-security=DIR where DIR is where the kerberos bits live\&. The configure script will then look in the \'lib\' directory under this hierarchy for libkrb\&.a\&.
113 parameter selects a communication/authentication method to use between the client and the backup server\&. These methods are described each in their own section below\&.
116 When Amanda is built, a username is specified with the
118 option\&. Most Amanda processes run under this user\'s identity, to minimize security risks\&. In binary distributions, this username is usually one of \'amanda\', \'amandabackup\', or \'backup\'\&. The examples below use \'amandabackup\' since it is unambiguous\&. You may need to adjust accordingly for your system\&.
119 .SS "Authenticated Peer Hostnames"
121 Amanda\'s authentication mechanisms provide an authenticated hostname of the system on the other end of the connection, which is used to restrict access to only particular hosts\&. The degree of "authentication" performed on this hostname varies with the authentication mechanism, and is discussed below\&.
122 .SH "BSD, BSDUDP, AND BSDTCP COMMUNICATION AND AUTHENTICATION"
124 For additional information including example configurations, see http://wiki\&.zmanda\&.com/index\&.php/Configuring_bsd/bsdudp/bsdtcp_authentication\&.
130 communication methods use either UDP, TCP, or both protocols operating as a network service to authenticate and exchange data between server and clients\&.
132 The authentication proceeds as follows: for a new, incoming connection, Amanda verifies that the source port is in the reserved range (less than 1024), which for UNIX hosts suggests that the remote user has root privileges\&. Amanda then verifies that the reverse DNS for the remote address matches the forward DNS; that is, that the address maps to a hostname which maps back to the same address\&. Finally, the remote system must provide a username that matches the username in \&.amandahosts\&.
134 In addition to compilation and general configuration (see
135 \fBCOMPILATION AND GENERAL INFORMATION\fR
136 above), the authentication method that the client is configured to receive is specified by the
138 parameter in the network service configuration for Amanda\&. The authentication method used by an Amanda client to reach the server during recovery is the authentication method specified by the
140 parameter in the client\'s Amanda network service configuration or in its amanda\-client\&.conf file (see amanda\-client\&.conf(5))\&.
142 By default, Amanda use the "amanda" service name and associated port set in /etc/services\&. It can be changed by setting the dumptype
144 option to a different port number or a different service name\&. All examples are for the service name "amanda" that uses the default port 10080\&.
145 .SS "\&.amandahosts file"
147 Servers and clients using the bsd, bsdudp, and bsdtcp authentication methods refer to the \&.amandahosts file to control access\&. Amanda should be compiled for this access control if one of these methods will be used and is the default compilation option for Amanda 2\&.6 (use \-\-with\-amandahosts when compiling pre\-2\&.6 versions of Amanda)\&.
149 Amanda looks for the \&.amandahosts file in the Amanda user\'s home directory, commonly /var/lib/amanda\&.
151 Each authorization is on its own line in the following format
157 \fIservice\&.\&.\&.\fR
162 is ommitted, it defaults to the user running
163 \fBamandad\fR, i\&.e\&. the user listed in the
167 configuration file\&.
169 \fIservice\&.\&.\&.\fR
170 is a space\-delimited list of services the client is authorized to execute:
176 (a shortcut for the previous four services which are required on clients),
178 \fBamidxtaped\fR\&. The last two services are required on a server for clients to connect to it using
181 If service is omitted, it defaults to
182 \fBnoop selfcheck sendsize sendbackup\fR
183 (which is equivalent to
186 Example of the \&.amandahosts file on an Amanda client, where \'amandabackup\' is the Amanda dumpuser\&.
189 \fBamandaserver\&.example\&.com amandabackup amdump\fR
192 Example of the \&.amandahosts file on an Amanda server
195 \fBamandaclient1\&.example\&.com root amindexd amidxtaped\fR
197 .SS "bsd communication and authentication"
199 The authentication is done using \&.amandahosts file in the Amanda user\'s home directory\&. The protocol between Amanda server and client is UDP\&. The number of disk list entries (DLEs)\-\-number of Amanda clients\-\-is limited by the UDP packet size\&. This authentication protocol will use a different port for each data stream (see PORT USAGE below)
200 .SS "bsdudp communication and authentication"
202 The authentication is done using \&.amandahosts files in the Amanda user\'s home directory\&. It uses UDP protocol between Amanda server and client for data and hence the number of DLEs is limited by the UDP packet size\&. It uses one TCP port to establish the connection and multiplexes all data streams using one port on the server (see PORT USAGE below)\&.
203 .SS "bsdtcp communication and authentication"
205 The authentication is done using \&.amandahosts files in the backup user\'s (for example: amandabackup) home directory\&. It uses TCP protocol between Amanda server and client\&. On the client, two reserved ports are used\&. On the server, all data streams are multiplexed to one port (see PORT USAGE below)\&.
206 .SS "USING INETD SERVER"
208 Template for Amanda client inetd service entry
211 \fI service_name\fR \fIsocket_type\fR \fIprotocol\fR \fIwait/nowait\fR \fIamanda_backup_user\fR \fIabsolute_path_to_amandad\fR amandad \fIserver_args\fR
214 Client example of using
216 authorization for inetd server given Amanda user is "amandabackup":
219 \fB amanda dgram udp wait amandabackup /path/to/amandad amandad \-auth=bsd amdump\fR
222 The same could be used for
224 if specifying \-auth=bsdudp instead of \-auth=bsd\&.
226 Client example of using
228 authorization for inetd server given Amanda user is "amandabackup":
231 \fB amanda stream tcp nowait amandabackup /path/to/amandad amandad \-auth=bsdtcp amdump\fR
237 would typically be added at the end of the line as
239 server arguments for an Amanda server\&.
241 Server example of using
243 authorization for inetd server given Amanda user is "amandabackup":
246 \fB amanda stream tcp nowait amandabackup /path/to/amandad amandad \-auth=bsdtcp amdump amindexd amidxtaped\fR
249 For Amanda version 2\&.5\&.0 and earlier, remember that neither
253 are supported and the Amanda daemon
255 accepts no arguments\&. Because of the latter,
257 as of Amanda version 2\&.5\&.1 is not compatible with 2\&.5\&.0 and earlier servers\&. Thus, servers that are 2\&.5\&.0 or earlier must, in addition to the
263 Amanda services as their own network services, amandaidx and amidxtape, respectively (see below)\&.
265 There are no compatibility issues if server and clients are all 2\&.5\&.0 or earlier\&. If your server is 2\&.5\&.1 or later, you can still have clients that are 2\&.5\&.0 and earlier although you must then use
267 communication/authentication with these clients and must also run
271 Amanda services on the server as their own network services, amandaidx and amidxtape, respectively (see below)\&. If you have a server that is 2\&.5\&.0 and earlier, clients of a later version on which you wish to run
275 instead and, again, the server must be running the amandaidx and amidxtape network services\&.
277 Example of amindexd and amidxtaped Amanda daemon services configured as their own network services for a 2\&.5\&.0 or earlier server or a newer server having 2\&.5\&.0 or earlier clients
280 \fB amandaidx stream tcp nowait amandabackup /usr/local/libexec/amanda/current/amindexd amindexd\fR
281 \fB amidxtape stream tcp nowait amandabackup /usr/local/libexec/amanda/current/amidxtaped amidxtaped\fR
283 .SS "USING XINETD SERVER"
285 Template for Amanda client xinetd service file
290 only_from = \fIAmanda server\fR
291 socket_type = \fIsocket type\fR
292 protocol = \fIprotocol\fR
294 user = \fIamanda backup user\fR
295 group = \fIamanda backup user group id\fR
297 server = \fIabsolute path to amandad\fR
298 server_args = \fIamandad server arguments\fR
305 parameter can be used with xinetd but is usually in addition to the primary form of access control via the \&.amandahosts file\&.
307 Client example of using
309 authorization for xinetd server and for Amanda user "amandabackup":
314 only_from = amandaserver\&.example\&.com
321 server = /path/to/amandad
322 server_args = \-auth=bsd amdump
327 The same could be used for
329 if specifying \-auth=bsdudp instead of \-auth=bsd\&.
331 Client example of using
333 authorization for xinetd server and for Amanda user "amandabackup":
338 only_from = amandaserver\&.example\&.com amandaclient\&.example\&.com
345 server = /path/to/amandad
346 server_args = \-auth=bsdtcp amdump
354 would typically be added as additional
357 for an Amanda server\&.
359 For Amanda version 2\&.5\&.0 and earlier, remember that neither
363 are supported and the Amanda daemon
365 accepts no arguments\&. Because of the latter,
367 as of Amanda version 2\&.5\&.1 is not compatible with 2\&.5\&.0 and earlier servers\&. Thus, servers that are 2\&.5\&.0 or earlier must, in addition to the
373 Amanda services as their own network services, amandaidx and amidxtape, respectively (see below)\&.
375 There are no compatibility issues if server and clients are all 2\&.5\&.0 or earlier\&. If your server is 2\&.5\&.1 or later, you can still have clients that are 2\&.5\&.0 and earlier although you must then use
377 communication/authentication with these clients and must also run
381 Amanda services on the server as their own network services, amandaidx and amidxtape, respectively (see below)\&. If you have a server that is 2\&.5\&.0 and earlier, clients of a later version on which you wish to run
385 instead and, again, the server must be running the amandaidx and amidxtape network services\&.
387 Example of amindexd and amidxtaped Amanda daemon services configured as their own network services for a 2\&.5\&.0 or earlier server or a newer server having 2\&.5\&.0 or earlier clients
397 server = /usr/local/libexec/amanda/amindexd
408 server = /usr/local/libexec/amanda/amidxtaped
414 List of TCP/UDP ports used by network service communication methods for Amanda server and client\&.
419 RPpAP = Reserved Port per Amanda Process
420 UPpDLE = Unreserved Port per DLE
421 [\&.\&.] = Configure options that can be used at compile time to define port ranges
423 Authentication Protocol Amanda server Amanda client
424 bsd udp 1 RPpAP [\-\-with\-udpportrange] 10080
425 tcp 1 UP [\-\-with\-tcpportrange] 3 UPpDLE [\-\-with\-tcpportrange]
426 bsdudp udp 1 RPpAP [\-\-with\-udpportrange] 10080
427 tcp 1 UP [\-with\-tcpportrange] 1 UPpDLE [\-\-with\-tcpportrange]
428 bsdtcp tcp 1 RPpAP [\-\-with\-low\-tcpportrange] 10080
431 Amanda server also uses two ports (dumper process) to communicate with the chunker/taper processes\&. These ports are in the range set by \-\-with\-tcpportrange\&.
433 You can override the default port ranges that Amanda was compiled with in each configuration using the
434 \fIreserved\-udp\-port\fR,
435 \fIreserved\-tcp\-port\fR, and
436 \fIunreserved\-tcp\-port\fR
437 parameters in amanda\&.conf and amanda\-client\&.conf configuration files (see
440 \fBamanda-client.conf\fR(5))\&.
441 .SS "Authenticated Peer Hostnames with BSD Authentications"
443 The BSD authentication mechanisms only verify that the remote host\'s DNS is configured correctly and that the remote user has access to reserved ports\&. As such, the peer hostname should only be trusted to the extent that the local DNS service is trusted\&.
444 .SH "KERBEROS COMMUNICATION AND AUTHENTICATION"
446 For more detail, see http://wiki\&.zmanda\&.com/index\&.php/Kerberos_authentication\&.
448 Amanda supports Kerberos 5 communication methods between Amanda server and client\&.
450 General information including compilation are given above (see
451 \fBCOMPILATION AND GENERAL INFORMATION\fR
454 Kerberos 5 uses TCP and the server uses only one TCP port and data streams are multiplexed to this port\&.
457 The \fBkrb5\fR driver script defaults to:
460 * The lifetime of our tickets in minutes\&.
462 #define AMANDA_TKT_LIFETIME (12*60)
465 * The name of the service in /etc/services\&.
467 #define AMANDA_KRB5_SERVICE_NAME "k5amanda"
471 You can currently only override these by editing the source code\&.
473 The kerberized AMANDA service uses a different port on the client hosts\&. The /etc/services line is:
478 And the /etc/inetd\&.conf line is:
481 k5amanda stream tcp nowait root /usr/local/libexec/amanda/amandad amandad \-auth=krb5
484 Note that you\'re running this as root, rather than as your dump user\&. AMANDA will set its UID down to the dump user at times it doesn\'t need to read the keytab file, and give up root permissions entirely before it goes off and runs dump\&. Alternately you can change your keytab files to be readable by user amanda\&. You should understand the security implications of this before changing the permissions on the keytab\&.
486 The following dumptype options apply to
490 auth "krb5" # use krb5 auth for this host
491 # (you can mingle krb hosts and bsd \&.rhosts in one conf)
494 The principal and keytab files that Amanda uses must be set in the amanda\&.conf file for kerberos 5 dumps to work\&. You can hardcode this in the source code if you really want to (common\-src/krb5\-security\&.c)
504 krb5keytab "/etc/krb5\&.keytab\-amanda"
505 krb5principal "amanda/saidin\&.omniscient\&.com"
508 The principal in the second option must be contained in the first\&. The keytab should be readable by the amanda user (and definitely not world readable!) and is (obviously) on the server\&. In MIT\'s kadmin, the following:
511 addprinc \-randkey amanda/saidin\&.omniscient\&.com
512 ktadd \-k /etc/krb5\&.keytab\-amanda amanda/saidin\&.omniscient\&.com
515 will do the trick\&. You will obviously want to change the principal name to reflect something appropriate for the conventions at your site\&.
517 You must also configure each client to allow the amanda principal in for dumps\&.
519 There are several ways to go about authorizing a server to connect to a client\&.
521 The normal way is via a \&.k5amandausers file or a \&.k5login file in the client user\'s home directory\&. The determination of which file to use is based on the way you ran configure on AMANDA\&. By default, AMANDA will use \&.k5amandahosts, but if you configured with \-\-without\-amandahosts, AMANDA will use \&.k5login\&. (similar to the default for \&.rhosts/\&.amandahosts\-style security)\&. The \&.k5login file syntax is a superset of the default
523 \&.k5login\&. The routines to check it are implemented in amanda rather than using krb5_kuserok because the connections are actually gssapi based\&.
525 This \&.k5amandahosts/\&.k5login is a hybrid of the \&.amandahosts and a \&.k5login file\&. You can just list principal names, as in a \&.k5login file and the principal will be permitted in from any host\&. If you do NOT specify a realm, then there is no attempt to validate the realm (this is only really a concern if you have cross\-realm authentication set up with another realm or something else that allows you multiple realms in your kdc\&. If you do specify a realm, only that principal@realm will be permitted to connect\&.
527 You may prepend this with a hostname and whitespace, and only that principal (with optional realm as above) will be permitted to access from that hostname\&.
529 Here are examples of valid entries in the \&.k5amandahosts:
533 service/amanda@TEST\&.COM
534 dumpmaster\&.test\&.com service/amanda
535 dumpmaster\&.test\&.com service/amanda@TEST\&.COM
538 Rather than using a \&.k5amandahosts or \&.k5login file, the easiest way is to use a principal named after the destination user, (such as amanda@TEST\&.COM in our example) and not have either a \&.k5amandahosts or \&.k5login file in the destination user\'s home directory\&.
540 There is no attempt to verify the realm in this case (only a concern if you have cross\-realm authentication setup)\&.
541 .SS "Authenticated Peer Hostnames with Kerberos Authentication"
543 When accepting a new incoming connection, the Kerberos authentication mechanism performs a similar check to that done by the BSD authentications: the forward and reverse DNS entries for the remote host must match\&. As such, while Kerberos authentication can cryptographically ensure that the remote system is recognized (since it has a ticket), its assurances about the remote host\'s identity are weaker and depend on the integrity of the DNS\&.
544 .SH "LOCAL COMMUNICATION"
546 The Amanda server communicates with the client internally versus over the network, ie\&. the client is also the server\&.
548 This is the only method that requires no authentication as it is clearly not needed\&.
550 The authenticated peer hostname for this authentication is always "localhost"\&.
551 .SH "RSH COMMUNICATION AND AUTHENTICATION"
553 For more detail, see http://wiki\&.zmanda\&.com/index\&.php/Configuring_rsh_authentication\&.
555 The Amanda server communicates with its client as the Amanda user via the RSH protocol\&.
557 Please note that RSH protocol itself is insecure and should be used with caution especially on any servers and clients with public IPs\&.
559 Each Amanda client communicates with the server using one TCP port and all data streams from the client are multiplexed over one port\&. The number of Amanda clients is limited by the number of reserved ports available on the Amanda server\&. Some versions of RSH do not use reserved ports and, thus, this restriction is not valid\&.
561 General information including compilation is given above (see
562 \fBCOMPILATION AND GENERAL INFORMATION\fR
565 In addition to specifying the
567 field in dumptype definition, it might be required to specify
568 \fIclient\-username\fR
571 fields\&. If the backup user name is different on the Amanda client, the user name is specified as
572 \fBclient\-username\fR\&. If the location of the Amanda daemon
574 is different on the Amanda client, the location is specified as
580 define dumptype rsh_example {
583 client\-username "amandabackup"
584 amandad\-path "/usr/lib/exec/amandad"
588 .SS "Authenticated Peer Hostnames with RSH Authentication"
590 The RSH authentication mechanism does not provide an authenticated peer hostname\&.
591 .SH "SSH COMMUNICATION AND AUTHENTICATION"
593 For more detail, see http://wiki\&.zmanda\&.com/index\&.php/How_To:Set_up_transport_encryption_with_SSH\&.
595 Amanda client sends data to the server using SSH\&. SSH keys have to be set up so that Amanda server can communicate with its clients using SSH\&.
597 General information including compilation is given above (see \fBCOMPILATION AND GENERAL INFORMATION\fR above)\&.
599 SSH provides transport encryption and authentication\&. To set up an SSH authentication session, Amanda will run the equivalent of the following to start the backup process\&.
601 \fB /path/to/ssh \-l \fR\fB\fIuser_name\fR\fR\fB client\&.zmanda\&.com $libexecdir/amandad\fR
603 To use SSH, you need to set up SSH keys either by storing the passphrase in cleartext, using ssh\-agent, or using no passphrase at all\&. All of these options have security implications which should be carefully considered before adoption\&.
605 When you use a public key on the client to do data encryption (see http://wiki\&.zmanda\&.com/index\&.php/How_To:Set_up_data_encryption), you can lock away the private key in a secure place\&. Both, transport and storage will be encrypted with such a setup\&. See http://wiki\&.zmanda\&.com/index\&.php/Encryption for an overview of encryption options\&.
607 Enable SSH authentication and set the \fBssh\-keys\fR option in all DLEs for that host by adding the following to the DLE itself or to the corresponding dumptype in amanda\&.conf:
610 ssh\-keys "/home/amandabackup/\&.ssh/id_rsa_amdump"
612 \fBssh\-keys\fR is the path to the private key on the client\&. If the username to which Amanda should connect is different from the default, then you should also add
614 client\-username "otherusername"
616 If your server \fBamandad\fR path and client \fBamandad\fR path are different, you should also add
618 amandad\-path "/client/amandad/path"
620 For a marginal increase in security, prepend the keys used for AMANDA in the clients\' authorized_keys file with the following:
623 from="amanda_server\&.your\&.domain\&.com",no\-port\-forwarding,no\-X11\-forwarding,no\-agent\-forwarding,command="/absolute/path/to/amandad \-auth=ssh amdump"
626 This will limit that key to connect only from Amanda server and only be able to execute
629 In the same way, prepend the key used for AMANDA in the server\'s authorized_keys file with:
632 from="amanda_client\&.your\&.domain\&.com",no\-port\-forwarding,no\-X11\-forwarding,no\-agent\-forwarding,command="/absolute/path/to/amandad \-auth=ssh amindexd amidxtaped"
635 You can omit the from=\&.\&. option if you have too many clients to list, although this has obvious security implications\&.
639 and any other necessary options in /etc/amanda/amanda_client\&.conf:
643 ssh\-keys "/root/\&.ssh/id_rsa_amrecover"
644 client\-username "amanda"
645 amandad\-path "/server/amandad/path"
648 Besides user keys, SSH uses host keys to uniquely identify each host, to prevent one host from impersonating another\&. Unfortunately, the only easy way to set up these host keys is to make a connection and tell SSH that you trust the identity:
651 $ ssh client1\&.zmanda\&.com
652 The authenticity of host \'client1\&.zmanda\&.com (192\&.168\&.10\&.1)\' can\'t be established\&.
653 RSA key fingerprint is 26:4e:df:a2:be:c8:cb:20:1c:68:8b:cc:c0:3b:8e:9d\&.
654 Are you sure you want to continue connecting (yes/no)?yes
657 As Amanda will not answer this question itself, you must manually make every connection (server to client and client to server) that you expect Amanda to make\&. Note that you must use the same username that Amanda will use (that is, ssh client and ssh client\&.domain\&.com are distinct)\&.
658 .SS "Authenticated Peer Hostnames with SSH Authentication"
660 When accepting an incoming conneciton, the SSH daemon gives Amanda information about the remote system in the $SSH_CONNECTION environment variable\&. Amanda parses this information to determine the remote address, and then performs a similar check to that done by the BSD authentications: the forward and reverse DNS entries for the remote host must match\&. As such, while SSH authentication can cryptographically ensure that the remote system is recognized (since it had a recognized secret key), its assurances about the remote host\'s identity are weaker and depend on the integrity of the DNS\&.
664 \fBamanda.conf\fR(5),
665 \fBamanda-client.conf\fR(5),
671 : http://wiki.zmanda.com/
674 \fBJean\-Louis Martineau\fR <\&martineau@zmanda\&.com\&>
676 Zmanda, Inc\&. (http://www\&.zmanda\&.com)
679 \fBDustin J\&. Mitchell\fR <\&dustin@zmanda\&.com\&>
681 Zmanda, Inc\&. (http://www\&.zmanda\&.com)
684 \fBPaul Yeatman\fR <\&pyeatman@zmanda\&.com\&>
686 Zmanda, Inc\&. (http://www\&.zmanda\&.com)
projects / debian / amanda / blob