PMDF System Manager's Guide

The following subsections provide examples of using BSMTP channels on OpenVMS.

23.2.2.1 Configuring the BSMTP Channels to Compress Their Payloads on OpenVMS

In the CHARSET-CONVERSION mapping table on each PMDF system, a simple entry enabling conversions for the BSMTP channels must be made:

CHARSET-CONVERSION in-chan=bsout_*;out-chan=*;convert yes in-chan=*;out-chan=bsin_*;convert yes

In the PMDF conversions file on each system, conversion entries are added which call out to the site-supplied command procedure, PMDF_COM:compress.com:

in-chan=bsout_*; part-number=1; in-type=*; in-subtype=*; service-command="@PMDF_COM:COMPRESS.COM COMPRESS 'INPUT_FILE' 'OUTPUT_FILE'" out-chan=bsin_*; part-number=1; in-type=application; in-subtype=compressed-bsmtp; service-command="@PMDF_COM:COMPRESS.COM DECOMPRESS 'INPUT_FILE' 'OUTPUT_FILE'"

The PMDF_COM:compress.com: command procedure is shown in Figure 23-1.

Figure 23-1 compress.com : Compress and decompress BSMTP payloads

$ ! $ ! Compress/decompress a MIME message using GZIP & GUNZIP $ ! P1 == "COMPRESS" | "DECOMPRESS" $ ! P2 == File to compress or decompress $ ! P3 == File containing the compressed or decompressed result $ ! $ ! Ensure that we have three command line arguments $ IF P1 .EQS. "" THEN EXIT 229448 ! DCL-W-INSFPRM $ IF P2 .EQS. "" THEN EXIT 229448 $ IF P3 .EQS. "" THEN EXIT 229448 $ ! $ ! Used for temporary files $ OUTFILE = F$ELEMENT(0,";",P3) $ ! $ ! Dispatch to the correct part of this command file $ IF "DECOMPRESS" .EQS. F$EDIT(P1,"TRIM,UPCASE) THEN GOTO DECOMPRESS $ IF "COMPRESS" .NES. F$EDIT(P1,"TRIM,UPCASE) THEN EXIT 229472 ! DCL-W-IVKEYW $ ! $ COMPRESS: $ GZIP = "$PMDF_EXE:GZIP.EXE" $ DEFINE/USER SYS$OUTPUT 'OUTFILE'-TMP $ GZIP -C 'P2' $ PMDF ENCODE/HEADER/TYPE=APPLICATION/SUBTYPE=COMPRESSED-BSMTP - 'OUTFILE'-TMP 'P3' $ DELETE/NOLOG 'OUTFILE'-TMP;* $ EXIT 1 $ ! $ DECOMPRESS: $ GUNZIP = "$PMDF_EXE:GUNZIP.EXE" $ PMDF DECODE/HEADER 'P2' 'OUTFILE'-TMP $ DEFINE/USER SYS$OUTPUT 'P3' $ GUNZIP -C 'OUTFILE-TMP' $ DELETE/NOLOG 'OUTFILE'-TMP;* $ EXIT 1

23.2.2.2 Configuring the BSMTP Channels to Provide Authentication Services on OpenVMS

In the CHARSET-CONVERSION mapping table on each PMDF system, a simple entry enabling conversions for the BSMTP channels must be made:

CHARSET-CONVERSION in-chan=bsout_*;out-chan=*;convert yes in-chan=*;out-chan=bsin_*;convert yes

In the PMDF conversions file on each system, there must be conversion entries to invoke the site-supplied command procedures:

in-chan=bsout_*; part-number=1; in-type=*; in-subtype=*; service-command="@PMDF_COM:PGP_SIGN.COM 'INPUT_FILE' 'OUTPUT_FILE'" out-chan=bsin_*; part-number=1; in-type=multipart; in-subtype=signed; service-command="@PMDF_COM:PGP_VERIFY.COM 'INPUT_FILE' 'OUTPUT_FILE'"

These two command procedures are shown in Figures 23-2 and 23-3. They assume that the PGP utility is the image D1:[pgp]pgp.exe. Note that the pgp_sign.com procedure requires the pass phrase for the PMDF MTA's private PGP key in order to generate signatures. Edit the procedure to reflect the correct pass phrase and be sure to protect the file from other users:

$ SET FILE/OWNER=[PMDF] PMDF_COM:PGP_SIGN.COM $ SET PROTECTION=(S:RWED,O:RWED,G,W) PMDF_COM:PGP_SIGN.COM

Figure 23-2 pgp_sign.com : Digitally sign BSMTP payloads

$ ! P1 == Input file specification; message to sign $ ! P2 == Output file specification; multipart/signed message $ ! P3 == File specification for the file of envelope recipient addresses $ ! $ ! Check that we have at least two command line parameters $ IF P1 .EQS. "" THEN EXIT 229448 ! DCL-W_INSFPRM $ IF P2 .EQS. "" THEN EXIT 229448 $ ! $ ! Basic definitions $ PGP = "$D1:[PGP]PGP.EXE" $ PGPUSER = "PMDF MTA key" $ PGPPATH = "PMDF_ROOT:[TABLE.PGP]" $ PGPPASS = "Percy eats pealed banannas" $ FILENAM = F$ELEMENT(0,";",P2) $ ! $ ! Error handling $ ON ERROR THEN GOTO ERROR $ ON SEVERE_ERROR THEN GOTO ERROR $ ! $ ! Generate the digital signature $ PGP "-sab" "-u" "''PGPUSER'" "-z" "''PGPPASS'" 'P1' "-o" 'FILENAM'-SIGN - "+batchmode" $ ! $ ! Get a unique string to use in a MIME boundary marker $ RUN PMDF_EXE:UNIQUE_ID.EXE $ BOUNDARY = "''unique_id'" $ ! $ ! Start the multipart message and the first message part $ OPEN/WRITE/ERROR=ERROR OUTFILE 'P2' $ WRT = "WRITE/ERROR=ERROR OUTFILE" $ WRT "Content-type: multipart/signed; boundary=''BOUNDARY';" $ WRT " micalg=pgp-md5; protocol=application/pgp-signature" $ WRT "" $ WRT "--''BOUNDARY'" $ CLOSE/ERROR=ERROR OUTFILE $ ! $ ! Start the second message part $ OPEN/WRITE/ERROR=ERROR OUTFILE 'FILENAM'-MID $ WRT "--''BOUNDARY'" $ WRT "Content-type: application/pgp-signature" $ WRT "" $ CLOSE/ERROR=ERROR OUTFILE $ ! $ ! And the end of the message $ OPEN/WRITE/ERROR=ERROR OUTFILE 'FILENAM'-BOT $ WRT "--''BOUNDARY'--" $ CLOSE/ERROR=ERROR OUTFILE $ ! $ ! Now glue all of the pieces together $ CONVERT/APPEND 'P1' 'P2' $ CONVERT/APPEND 'FILENAM'-MID 'P2' $ CONVERT/APPEND 'FILENAM'-SIGN 'P2' $ CONVERT/APPEND 'FILENAM'-BOT 'P2' $ ! $ ! Delete the temporary files $ DELETE/NOLOG 'FILENAM'-MID;*,'FILENAM'-SIGN;*,'FILENAM'-BOT;* $ EXIT 1 $ ! $ ! We fall through to here when we have an error $ ERROR: $ SET NOON $ IF F$TRNLNM("OUTFILE") .NES. "" THEN CLOSE OUTFILE $ DELETE/NOLOG 'FILENAM'-*.*,'P2' $ SET ON $ EXIT 2

Figure 23-3 pgp_verify.com : Verify the integrity of a digitally signed BSMTP payload

$ ! P1 == Input file specification; multipart/signed message $ ! P2 == Output file specification; message which was signed; $ ! P3 == File specification for the file of envelope recipient addresses $ ! $ ! Check that we have at least two command line parameters $ IF P1 .EQS. "" THEN EXIT 229448 ! DCL-W-INSFPRM $ IF P2 .EQS. "" THEN EXIT 229448 $ ! $ ! Basic definitions $ PGP = "$D1:[PGP]PGP.EXE" $ PGPPATH = "PMDF_ROOT:[TABLE.PGP]" $ FILENAM = F$ELEMENT(0,";",P2) $ ! $ ! Error handling $ ON ERROR THEN GOTO ERROR $ ON SEVERE_ERROR THEN GOTO ERROR $ ! $ ! Reformat the input file to look like a PGP signature file $ OPEN/READ/ERROR=ERROR INFILE 'P1' $ OPEN/WRITE/ERROR=ERROR OUTFILE 'FILENAM'-SIGN $ WRT = "WRITE/ERROR=ERROR OUTFILE" $ STATE = 1 $ LOOP: $ READ/ERROR=ERROR/END_OF_FILE=END_LOOP INFILE LINE $ IF STATE .EQ. 1 $ THEN $ IF F$EXTRACT(0,2,LINE) .EQS. "--" $ THEN $ STATE = 2 $ BOUNDARY = LINE $ WRT "-----BEGIN PGP SIGNED MESSAGE-----" $ WRT "" $ ENDIF $ ELSE $ IF STATE .EQ. 2 $ THEN $ IF BOUNDARY .NES. LINE $ THEN $ WRT LINE $ ELSE $ STATE = 3 $ ENDIF $ ELSE $ IF STATE .EQ. 3 $ THEN $ IF LINE .EQS. "" $ THEN $ STATE = 4 $ WRT "" $ ENDIF $ ELSE $ WRT LINE $ ENDIF $ ENDIF $ ENDIF $ GOTO LOOP $ ! $ END_LOOP: $ CLOSE/ERROR=ERROR INFILE $ CLOSE/ERROR=ERROR OUTFILE $ ! $ ! Now check the signature $ DEFINE/USER SYS$OUTPUT 'FILENAM'-CHECK $ PGP "-o" 'FILENAM'-OUT 'FILENAM'-SIGN "+batchmode" $ ! $ ! See what the results of the check were; build the X-Content-MIC-check: line $ SEARCH/OUTPUT='FILENAM'-MIC/EXACT 'FILENAM'-CHECK " signature from user " $ IF $STATUS .EQ. 1 $ THEN $ OPEN/READ/ERROR=ERROR INFILE 'FILENAM'-MIC $ READ/ERROR=ERROR INFILE LINE $ CLOSE/ERROR=ERROR INFILE $ MIC_CHECK = "X-Content-MIC-check: "+LINE $ ELSE $ MIC_CHECK = "X-Content-MIC-check: Bad signature" $ ENDIF $ OPEN/WRITE/ERROR=ERROR OUTFILE 'P2' $ WRITE/ERROR=ERROR OUTFILE MIC_CHECK $ CLOSE/ERROR=ERROR OUTFILE $ ! $ ! Now assemble the result: the MIC check + signed data $ CONVERT/APPEND 'FILENAM'-OUT 'P2' $ DELETE/NOLOG 'FILENAM'-*.* $ EXIT 1 $ ! $ ! We fall through to here when there is an error $ ERROR: $ SET NOON $ IF F$TRNLNM("INFILE") .NES. "" THEN CLOSE INFILE $ IF F$TRNLNM("OUTFILE") .NES. "" THEN CLOSE OUTFILE $ DELETE/NOLOG 'FILENAM'-*.*,'P2' $ SET ON $ EXIT 2

23.2.2.2.1 Using PGP with PMDF on OpenVMS

Use of PGP requires installation of PGP as well as generation and exchange of PGP public keys between the PMDF BSMTP systems which will be using PGP for authentication. This section documents step-by-step how to generate and exchange PGP keys. No attempt is here made to document PGP. Please refer to the documentation supplied with PGP for information on those subjects.

1. Acquire copies of PGP and install it on the PMDF systems. The following URLs might be helpful:

   <http://www.pgp.com/> <ftp://ftp.csn.net/mpj/getpgp.asc> <http://world.std.com/~franl/pgp/where-to-get-pgp.html>

2. After installing PGP, create an MTA key for the PMDF system. Note that the name for the key will be bsmtp@bsin.host0 where host0 is as in Section 23.1. The important element here is that the remote BSMTP channel will send the message to the address bsmtp@bsin.host0. The local PMDF system will receive that message and, via the FORWARD mapping table, route it to the incoming BSMTP channel, bsin_gateway, for the recipient bsmtp@bsin.host0. This recipient address is the user id of the decryption key which will be used. The PGP key rings need to be located somewhere; placing them in the directory pmdf_root:[table.pgp] is as good as place as any. The easiest way to set this up is as follows:

   $ SET DEFAULT PMDF_ROOT:[TABLE] $ CREATE/DIR/OWNER=[PMDF] [.PGP] $ PGPPATH == "PMDF_ROOT:[TABLE.PGP] $ PGP -kg Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses. (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94 Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc. Distributed by the Massachusetts Institute of Technology. Export of this software may be restricted by the U.S. government. Current time: 1997/04/02 20:44 GMT Pick your RSA key size: 1) 512 bits- Low commercial grade, fast but less secure 2) 768 bits- High commercial grade, medium speed, good security 3) 1024 bits- "Military" grade, slow, highest security Choose 1, 2, or 3, or enter desired number of bits: 3 Generating an RSA key with a 1024-bit modulus. You need a user ID for your public key. The desired form for this user ID is your name, followed by your E-mail address enclosed in <angle brackets>, if you have an E-mail address. For example: John Q. Smith <12345.6789@compuserve.com> Enter a user ID for your public key: PMDF MTA key <bsmtp@bsin.host0> You need a pass phrase to protect your RSA secret key. Your pass phrase can be any sentence or phrase and may have many words, spaces, punctuation, or any other printable characters. Enter pass phrase: secret Enter same pass phrase again: secret Note that key generation is a lengthy process. We need to generate 736 random bits. This is done by measuring the time intervals between your keystrokes. Please enter some random text on your keyboard until you hear the beep: 0 * -Enough, thank you. ....**** ..............**** Key generation completed. $ DIRECTORY/PROTECTION/SIZE=ALL [.PGP] Directory PMDF_ROOT:[TABLE.PGP] PUBRING.BAK;1 1/16 (RWED,RWED,,) PUBRING.PGP;1 1/16 (RWED,RWED,,) RANDSEED.BIN;1 1/16 (RWED,RWED,,) SECRING.PGP;1 2/16 (RWED,RWED,,) Total of 4 files, 5/64 blocks.

   The final directory command verifies that the correct three PGP files have been created with appropriate rights.

3. You may want change the protections of the file pubring.pgp so that others can read the public key:

   $ SET PROTECTION=(W:RE) [.PGP]PUBRING.PGP

4. Now you need to sign your public key. This prevents someone else from modifying the user id of the key.

   $ PGP -ks "bsmtp@bsin.host0" Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses. (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94 Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc. Distributed by the Massachusetts Institute of Technology. Export of this software may be restricted by the U.S. government. Current time: 1997/04/02 20:46 GMT A secret key is required to make a signature. You specified no user ID to select your secret key, so the default user ID and key will be the most recently added key on your secret keyring. Looking for key for user 'bsmtp@bsin.host0': Key for user ID: PMDF MTA key <bsmtp@bsin.host0> 1024-bit key, Key ID BFFA43E9, created 1997/04/02 Key fingerprint = 2F 5C A1 0A 35 25 E1 23 ED AF 23 11 00 37 5A CD READ CAREFULLY: Based on your own direct first-hand knowledge, are you absolutely certain that you are prepared to solemnly certify that the above public key actually belongs to the user specified by the above user ID (y/N)? y You need a pass phrase to unlock your RSA secret key. Key for user ID "PMDF MTA key <bsmtp@bsin.host0>" Enter pass phrase: secret Pass phrase is good. Just a moment.... Key signature certificate added.

5. Repeat Steps (1)---(4) on the other PMDF systems.
6. Next, you need to exchange public keys between the PMDF systems. On a given system, you may extract the public key as follows:

   $ PGP -kxa "bsmtp@bsin.host0" extract Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses. (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94 Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc. Distributed by the Massachusetts Institute of Technology. Export of this software may be restricted by the U.S. government. Current time: 1997/04/02 20:47 GMT Extracting from key ring: '/pmdf/table/.pgp/pubring.pgp', userid "bsmtp@bsin.host0". Key for user ID: PMDF MTA key <bsmtp@bsin.host0> 1024-bit key, Key ID BFFA43E9, created 1997/04/02 Transport armor file: extract.asc Key extracted to file 'extract.asc'.

   The file extract.asc may then be transferred by FTP or e-mail to the other PMDF system. If you're exchanging keys with another server you control go on to the next step. However, if you're exchanging keys with a remote site, some care needs to be taken to make sure the public keys are properly certified.

7. The best way to exchange keys is to first exchange the key fingerprints via a reliable channel (e.g., face-to-face in person, or perhaps over a trusted phone line). The fingerprint can be obtained with the following command:

   $ PGP -kvc bsmtp@bsin.host0 Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses. (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94 Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc. Distributed by the Massachusetts Institute of Technology. Export of this software may be restricted by the U.S. government. Current time: 1997/04/02 23:08 GMT Key ring: '/pmdf/table/.pgp/pubring.pgp', looking for user ID "bsmtp@bsin.host0". Type bits/keyID Date User ID pub 1024/BFFA43E9 1997/04/02 PMDF MTA key <bsmtp@bsin.host0> Key fingerprint = 2F 5C A1 0A 35 25 E1 23 ED AF 23 11 00 37 5A CD 1 matching key found.

   Then the public key itself can be extracted as described in Step (6) and sent through e-mail. Upon receipt, the fingerprint should be manually verified before certifying the key. After adding and certifying the key for the remote server, you may want to sign that key as well. If you sign the key, and extract it as described in Step (6) this can be used to tell other people you believe that key actually belongs to the MTA it claims to belong to. For more information, see the PGP documentation.

8. Add the key in extract.asc to the keyrings on the other PMDF systems. If you are unsure about how to answer the questions, see the PGP User's Manual.

   $ PGP EXTRACT.ASC Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses. (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94 Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc. Distributed by the Massachusetts Institute of Technology. Export of this software may be restricted by the U.S. government. Current time: 1997/04/02 21:09 GMT File contains key(s). Contents follow... Key ring: 'extract.$00' Type bits/keyID Date User ID pub 1024/BFFA43E9 1997/04/02 PMDF MTA key <bsmtp@bsin.host0> sig BFFA43E9 PMDF MTA key <bsmtp@bsin.host0> 1 matching key found. Do you want to add this keyfile to keyring '/pmdf/table/.pgp/pubring.pgp' (y/N)? y Looking for new keys... pub 1024/BFFA43E9 1997/04/02 PMDF MTA key <bsmtp@bsin.host0> Checking signatures... pub 1024/BFFA43E9 1997/04/02 PMDF MTA key <bsmtp@bsin.host0> sig! BFFA43E9 1997/04/02 PMDF MTA key <bsmtp@bsin.host0> Keyfile contains: 1 new key(s) One or more of the new keys are not fully certified. Do you want to certify any of these keys yourself (y/N)? y Key for user ID: PMDF MTA key <bsmtp@bsin.host0> 1024-bit key, Key ID BFFA43E9, created 1997/04/02 Key fingerprint = 2F 5C A1 0A 35 25 E1 23 ED AF 23 11 00 37 5A CD This key/userID association is not certified. Questionable certification from: PMDF MTA key <bsmtp@bsin.host0> Do you want to certify this key yourself (y/N)? y Looking for key for user 'PMDF MTA key <bsmtp@bsin.host0>': Key for user ID: PMDF MTA key <bsmtp@bsin.host0> 1024-bit key, Key ID BFFA43E9, created 1997/04/02 Key fingerprint = 2F 5C A1 0A 35 25 E1 23 ED AF 23 11 00 37 5A CD READ CAREFULLY: Based on your own direct first-hand knowledge, are you absolutely certain that you are prepared to solemnly certify that the above public key actually belongs to the user specified by the above user ID (y/N)? y You need a pass phrase to unlock your RSA secret key. Key for user ID "PMDF MTA key <bsmtp@bsin.host1>" Enter pass phrase: another-secret Pass phrase is good. Just a moment.... Key signature certificate added. Make a determination in your own mind whether this key actually belongs to the person whom you think it belongs to, based on available evidence. If you think it does, then based on your estimate of that person's integrity and competence in key management, answer the following question: Would you trust "PMDF MTA key <bsmtp@bsin.host0>" to act as an introducer and certify other people's public keys to you? (1=I don't know. 2=No. 3=Usually. 4=Yes, always.) ? 2

9. Repeat Steps (6)---(8) in the other direction.
10. You may check which keys are on your keyring with the following command:

    $ PGP -kv Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses. (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94 Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc. Distributed by the Massachusetts Institute of Technology. Export of this software may be restricted by the U.S. government. Current time: 1997/04/02 23:23 GMT Key ring: '/pmdf/table/.pgp/pubring.pgp' Type bits/keyID Date User ID pub 1024/BFFA43E9 1997/04/02 PMDF MTA key <bsmtp@bsin.host0> pub 1024/6405957D 1997/03/17 PMDF MTA key <bsmtp@bsin.host0> 2 matching keys found.

Once you have exchanged the keys, you should then be able to send digitally signed BSMTP parcels.