Import OpenSSL-1.0.1h.
[dragonfly.git] / crypto / openssl / doc / apps / cms.pod
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1=pod
2
3=head1 NAME
4
5cms - CMS utility
6
7=head1 SYNOPSIS
8
9B<openssl> B<cms>
10[B<-encrypt>]
11[B<-decrypt>]
12[B<-sign>]
13[B<-verify>]
14[B<-cmsout>]
15[B<-resign>]
16[B<-data_create>]
17[B<-data_out>]
18[B<-digest_create>]
19[B<-digest_verify>]
20[B<-compress>]
21[B<-uncompress>]
22[B<-EncryptedData_encrypt>]
23[B<-sign_receipt>]
24[B<-verify_receipt receipt>]
25[B<-in filename>]
26[B<-inform SMIME|PEM|DER>]
27[B<-rctform SMIME|PEM|DER>]
28[B<-out filename>]
29[B<-outform SMIME|PEM|DER>]
30[B<-stream -indef -noindef>]
31[B<-noindef>]
32[B<-content filename>]
33[B<-text>]
34[B<-noout>]
35[B<-print>]
36[B<-CAfile file>]
37[B<-CApath dir>]
38[B<-md digest>]
39[B<-[cipher]>]
40[B<-nointern>]
41[B<-no_signer_cert_verify>]
42[B<-nocerts>]
43[B<-noattr>]
44[B<-nosmimecap>]
45[B<-binary>]
46[B<-nodetach>]
47[B<-certfile file>]
48[B<-certsout file>]
49[B<-signer file>]
50[B<-recip file>]
51[B<-keyid>]
52[B<-receipt_request_all -receipt_request_first>]
53[B<-receipt_request_from emailaddress>]
54[B<-receipt_request_to emailaddress>]
55[B<-receipt_request_print>]
56[B<-secretkey key>]
57[B<-secretkeyid id>]
58[B<-econtent_type type>]
59[B<-inkey file>]
60[B<-passin arg>]
61[B<-rand file(s)>]
62[B<cert.pem...>]
63[B<-to addr>]
64[B<-from addr>]
65[B<-subject subj>]
66[cert.pem]...
67
68=head1 DESCRIPTION
69
70The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
71verify, compress and uncompress S/MIME messages.
72
73=head1 COMMAND OPTIONS
74
75There are fourteen operation options that set the type of operation to be
76performed. The meaning of the other options varies according to the operation
77type.
78
79=over 4
80
81=item B<-encrypt>
82
83encrypt mail for the given recipient certificates. Input file is the message
84to be encrypted. The output file is the encrypted mail in MIME format. The
85actual CMS type is <B>EnvelopedData<B>.
86
87=item B<-decrypt>
88
89decrypt mail using the supplied certificate and private key. Expects an
90encrypted mail message in MIME format for the input file. The decrypted mail
91is written to the output file.
92
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93=item B<-debug_decrypt>
94
95this option sets the B<CMS_DEBUG_DECRYPT> flag. This option should be used
96with caution: see the notes section below.
97
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98=item B<-sign>
99
100sign mail using the supplied certificate and private key. Input file is
101the message to be signed. The signed message in MIME format is written
102to the output file.
103
104=item B<-verify>
105
106verify signed mail. Expects a signed mail message on input and outputs
107the signed data. Both clear text and opaque signing is supported.
108
109=item B<-cmsout>
110
111takes an input message and writes out a PEM encoded CMS structure.
112
113=item B<-resign>
114
115resign a message: take an existing message and one or more new signers.
116
117=item B<-data_create>
118
119Create a CMS B<Data> type.
120
121=item B<-data_out>
122
123B<Data> type and output the content.
124
125=item B<-digest_create>
126
127Create a CMS B<DigestedData> type.
128
129=item B<-digest_verify>
130
131Verify a CMS B<DigestedData> type and output the content.
132
133=item B<-compress>
134
135Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
136support for this option to work, otherwise it will output an error.
137
138=item B<-uncompress>
139
140Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
141compiled with B<zlib> support for this option to work, otherwise it will
142output an error.
143
144=item B<-EncryptedData_encrypt>
145
146Encrypt suppled content using supplied symmetric key and algorithm using a CMS
147B<EncrytedData> type and output the content.
148
149=item B<-sign_receipt>
150
151Generate and output a signed receipt for the supplied message. The input
152message B<must> contain a signed receipt request. Functionality is otherwise
153similar to the B<-sign> operation.
154
155=item B<-verify_receipt receipt>
156
157Verify a signed receipt in filename B<receipt>. The input message B<must>
158contain the original receipt request. Functionality is otherwise similar
159to the B<-verify> operation.
160
161=item B<-in filename>
162
163the input message to be encrypted or signed or the message to be decrypted
164or verified.
165
166=item B<-inform SMIME|PEM|DER>
167
168this specifies the input format for the CMS structure. The default
169is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
170format change this to expect PEM and DER format CMS structures
171instead. This currently only affects the input format of the CMS
172structure, if no CMS structure is being input (for example with
173B<-encrypt> or B<-sign>) this option has no effect.
174
175=item B<-rctform SMIME|PEM|DER>
176
177specify the format for a signed receipt for use with the B<-receipt_verify>
178operation.
179
180=item B<-out filename>
181
182the message text that has been decrypted or verified or the output MIME
183format message that has been signed or verified.
184
185=item B<-outform SMIME|PEM|DER>
186
187this specifies the output format for the CMS structure. The default
188is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
189format change this to write PEM and DER format CMS structures
190instead. This currently only affects the output format of the CMS
191structure, if no CMS structure is being output (for example with
192B<-verify> or B<-decrypt>) this option has no effect.
193
194=item B<-stream -indef -noindef>
195
196the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
197for encoding operations. This permits single pass processing of data without
198the need to hold the entire contents in memory, potentially supporting very
199large files. Streaming is automatically set for S/MIME signing with detached
200data if the output format is B<SMIME> it is currently off by default for all
201other operations.
202
203=item B<-noindef>
204
205disable streaming I/O where it would produce and indefinite length constructed
206encoding. This option currently has no effect. In future streaming will be
207enabled by default on all relevant operations and this option will disable it.
208
209=item B<-content filename>
210
211This specifies a file containing the detached content, this is only
212useful with the B<-verify> command. This is only usable if the CMS
213structure is using the detached signature form where the content is
214not included. This option will override any content if the input format
215is S/MIME and it uses the multipart/signed MIME content type.
216
217=item B<-text>
218
219this option adds plain text (text/plain) MIME headers to the supplied
220message if encrypting or signing. If decrypting or verifying it strips
221off text headers: if the decrypted or verified message is not of MIME
222type text/plain then an error occurs.
223
224=item B<-noout>
225
226for the B<-cmsout> operation do not output the parsed CMS structure. This
227is useful when combined with the B<-print> option or if the syntax of the CMS
228structure is being checked.
229
230=item B<-print>
231
232for the B<-cmsout> operation print out all fields of the CMS structure. This
233is mainly useful for testing purposes.
234
235=item B<-CAfile file>
236
237a file containing trusted CA certificates, only used with B<-verify>.
238
239=item B<-CApath dir>
240
241a directory containing trusted CA certificates, only used with
242B<-verify>. This directory must be a standard certificate directory: that
243is a hash of each subject name (using B<x509 -hash>) should be linked
244to each certificate.
245
246=item B<-md digest>
247
248digest algorithm to use when signing or resigning. If not present then the
249default digest algorithm for the signing key will be used (usually SHA1).
250
251=item B<-[cipher]>
252
253the encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
254or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
255EVP_get_cipherbyname() function) can also be used preceded by a dash, for
256example B<-aes_128_cbc>. See L<B<enc>|enc(1)> for a list of ciphers
257supported by your version of OpenSSL.
258
259If not specified triple DES is used. Only used with B<-encrypt> and
260B<-EncryptedData_create> commands.
261
262=item B<-nointern>
263
264when verifying a message normally certificates (if any) included in
265the message are searched for the signing certificate. With this option
266only the certificates specified in the B<-certfile> option are used.
267The supplied certificates can still be used as untrusted CAs however.
268
269=item B<-no_signer_cert_verify>
270
271do not verify the signers certificate of a signed message.
272
273=item B<-nocerts>
274
275when signing a message the signer's certificate is normally included
276with this option it is excluded. This will reduce the size of the
277signed message but the verifier must have a copy of the signers certificate
278available locally (passed using the B<-certfile> option for example).
279
280=item B<-noattr>
281
282normally when a message is signed a set of attributes are included which
283include the signing time and supported symmetric algorithms. With this
284option they are not included.
285
286=item B<-nosmimecap>
287
288exclude the list of supported algorithms from signed attributes, other options
289such as signing time and content type are still included.
290
291=item B<-binary>
292
293normally the input message is converted to "canonical" format which is
294effectively using CR and LF as end of line: as required by the S/MIME
295specification. When this option is present no translation occurs. This
296is useful when handling binary data which may not be in MIME format.
297
298=item B<-nodetach>
299
300when signing a message use opaque signing: this form is more resistant
301to translation by mail relays but it cannot be read by mail agents that
302do not support S/MIME. Without this option cleartext signing with
303the MIME type multipart/signed is used.
304
305=item B<-certfile file>
306
307allows additional certificates to be specified. When signing these will
308be included with the message. When verifying these will be searched for
309the signers certificates. The certificates should be in PEM format.
310
311=item B<-certsout file>
312
313any certificates contained in the message are written to B<file>.
314
315=item B<-signer file>
316
317a signing certificate when signing or resigning a message, this option can be
318used multiple times if more than one signer is required. If a message is being
319verified then the signers certificates will be written to this file if the
320verification was successful.
321
322=item B<-recip file>
323
324the recipients certificate when decrypting a message. This certificate
325must match one of the recipients of the message or an error occurs.
326
327=item B<-keyid>
328
329use subject key identifier to identify certificates instead of issuer name and
330serial number. The supplied certificate B<must> include a subject key
331identifier extension. Supported by B<-sign> and B<-encrypt> options.
332
333=item B<-receipt_request_all -receipt_request_first>
334
335for B<-sign> option include a signed receipt request. Indicate requests should
336be provided by all receipient or first tier recipients (those mailed directly
337and not from a mailing list). Ignored it B<-receipt_request_from> is included.
338
339=item B<-receipt_request_from emailaddress>
340
341for B<-sign> option include a signed receipt request. Add an explicit email
342address where receipts should be supplied.
343
344=item B<-receipt_request_to emailaddress>
345
346Add an explicit email address where signed receipts should be sent to. This
347option B<must> but supplied if a signed receipt it requested.
348
349=item B<-receipt_request_print>
350
351For the B<-verify> operation print out the contents of any signed receipt
352requests.
353
354=item B<-secretkey key>
355
356specify symmetric key to use. The key must be supplied in hex format and be
357consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
358B<-EncrryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
359with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
360content encryption key using an AES key in the B<KEKRecipientInfo> type.
361
362=item B<-secretkeyid id>
363
364the key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
365This option B<must> be present if the B<-secretkey> option is used with
366B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
367relevant key if it is not supplied then an attempt is used to decrypt any
368B<KEKRecipientInfo> structures.
369
370=item B<-econtent_type type>
371
372set the encapsulated content type to B<type> if not supplied the B<Data> type
373is used. The B<type> argument can be any valid OID name in either text or
374numerical format.
375
376=item B<-inkey file>
377
378the private key to use when signing or decrypting. This must match the
379corresponding certificate. If this option is not specified then the
380private key must be included in the certificate file specified with
381the B<-recip> or B<-signer> file. When signing this option can be used
382multiple times to specify successive keys.
383
384=item B<-passin arg>
385
386the private key password source. For more information about the format of B<arg>
387see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
388
389=item B<-rand file(s)>
390
391a file or files containing random data used to seed the random number
392generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
393Multiple files can be specified separated by a OS-dependent character.
394The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
395all others.
396
397=item B<cert.pem...>
398
399one or more certificates of message recipients: used when encrypting
400a message.
401
402=item B<-to, -from, -subject>
403
404the relevant mail headers. These are included outside the signed
405portion of a message so they may be included manually. If signing
406then many S/MIME mail clients check the signers certificate's email
407address matches that specified in the From: address.
408
409=item B<-purpose, -ignore_critical, -issuer_checks, -crl_check, -crl_check_all, -policy_check, -extended_crl, -x509_strict, -policy -check_ss_sig>
410
411Set various certificate chain valiadition option. See the
412L<B<verify>|verify(1)> manual page for details.
413
414=back
415
416=head1 NOTES
417
418The MIME message must be sent without any blank lines between the
419headers and the output. Some mail programs will automatically add
420a blank line. Piping the mail directly to sendmail is one way to
421achieve the correct format.
422
423The supplied message to be signed or encrypted must include the
424necessary MIME headers or many S/MIME clients wont display it
425properly (if at all). You can use the B<-text> option to automatically
426add plain text headers.
427
428A "signed and encrypted" message is one where a signed message is
429then encrypted. This can be produced by encrypting an already signed
430message: see the examples section.
431
432This version of the program only allows one signer per message but it
433will verify multiple signers on received messages. Some S/MIME clients
434choke if a message contains multiple signers. It is possible to sign
435messages "in parallel" by signing an already signed message.
436
437The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
438clients. Strictly speaking these process CMS enveloped data: CMS
439encrypted data is used for other purposes.
440
441The B<-resign> option uses an existing message digest when adding a new
442signer. This means that attributes must be present in at least one existing
443signer using the same message digest or this operation will fail.
444
445The B<-stream> and B<-indef> options enable experimental streaming I/O support.
446As a result the encoding is BER using indefinite length constructed encoding
447and no longer DER. Streaming is supported for the B<-encrypt> operation and the
448B<-sign> operation if the content is not detached.
449
450Streaming is always used for the B<-sign> operation with detached data but
451since the content is no longer part of the CMS structure the encoding
452remains DER.
453
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454If the B<-decrypt> option is used without a recipient certificate then an
455attempt is made to locate the recipient by trying each potential recipient
456in turn using the supplied private key. To thwart the MMA attack
457(Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all recipients are
458tried whether they succeed or not and if no recipients match the message
459is "decrypted" using a random key which will typically output garbage.
460The B<-debug_decrypt> option can be used to disable the MMA attack protection
461and return an error if no recipient can be found: this option should be used
462with caution. For a fuller description see L<CMS_decrypt(3)|CMS_decrypt(3)>).
463
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464=head1 EXIT CODES
465
466=over 4
467
4bb195ec 468=item Z<>0
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469
470the operation was completely successfully.
471
4bb195ec 472=item Z<>1
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473
474an error occurred parsing the command options.
475
4bb195ec 476=item Z<>2
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477
478one of the input files could not be read.
479
4bb195ec 480=item Z<>3
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481
482an error occurred creating the CMS file or when reading the MIME
483message.
484
4bb195ec 485=item Z<>4
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486
487an error occurred decrypting or verifying the message.
488
4bb195ec 489=item Z<>5
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490
491the message was verified correctly but an error occurred writing out
492the signers certificates.
493
494=back
495
496=head1 COMPATIBILITY WITH PKCS#7 format.
497
498The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
499utility supports Cryptographic Message Syntax format. Use of some features
500will result in messages which cannot be processed by applications which only
501support the older format. These are detailed below.
502
503The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
504
505The B<-outform PEM> option uses different headers.
506
507The B<-compress> option.
508
509The B<-secretkey> option when used with B<-encrypt>.
510
511Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
512be processed by the older B<smime> command.
513
514=head1 EXAMPLES
515
516Create a cleartext signed message:
517
518 openssl cms -sign -in message.txt -text -out mail.msg \
519 -signer mycert.pem
520
521Create an opaque signed message
522
523 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
524 -signer mycert.pem
525
526Create a signed message, include some additional certificates and
527read the private key from another file:
528
529 openssl cms -sign -in in.txt -text -out mail.msg \
530 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
531
532Create a signed message with two signers, use key identifier:
533
534 openssl cms -sign -in message.txt -text -out mail.msg \
535 -signer mycert.pem -signer othercert.pem -keyid
536
537Send a signed message under Unix directly to sendmail, including headers:
538
539 openssl cms -sign -in in.txt -text -signer mycert.pem \
540 -from steve@openssl.org -to someone@somewhere \
541 -subject "Signed message" | sendmail someone@somewhere
542
543Verify a message and extract the signer's certificate if successful:
544
545 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
546
547Send encrypted mail using triple DES:
548
549 openssl cms -encrypt -in in.txt -from steve@openssl.org \
550 -to someone@somewhere -subject "Encrypted message" \
551 -des3 user.pem -out mail.msg
552
553Sign and encrypt mail:
554
555 openssl cms -sign -in ml.txt -signer my.pem -text \
556 | openssl cms -encrypt -out mail.msg \
557 -from steve@openssl.org -to someone@somewhere \
558 -subject "Signed and Encrypted message" -des3 user.pem
559
560Note: the encryption command does not include the B<-text> option because the
561message being encrypted already has MIME headers.
562
563Decrypt mail:
564
565 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
566
567The output from Netscape form signing is a PKCS#7 structure with the
568detached signature format. You can use this program to verify the
569signature by line wrapping the base64 encoded structure and surrounding
570it with:
571
572 -----BEGIN PKCS7-----
573 -----END PKCS7-----
574
575and using the command,
576
577 openssl cms -verify -inform PEM -in signature.pem -content content.txt
578
579alternatively you can base64 decode the signature and use
580
581 openssl cms -verify -inform DER -in signature.der -content content.txt
582
583Create an encrypted message using 128 bit Camellia:
584
585 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
586
587Add a signer to an existing message:
588
589 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
590
591=head1 BUGS
592
593The MIME parser isn't very clever: it seems to handle most messages that I've
594thrown at it but it may choke on others.
595
596The code currently will only write out the signer's certificate to a file: if
597the signer has a separate encryption certificate this must be manually
598extracted. There should be some heuristic that determines the correct
599encryption certificate.
600
601Ideally a database should be maintained of a certificates for each email
602address.
603
604The code doesn't currently take note of the permitted symmetric encryption
605algorithms as supplied in the SMIMECapabilities signed attribute. this means the
606user has to manually include the correct encryption algorithm. It should store
607the list of permitted ciphers in a database and only use those.
608
609No revocation checking is done on the signer's certificate.
610
611=head1 HISTORY
612
613The use of multiple B<-signer> options and the B<-resign> command were first
614added in OpenSSL 1.0.0
615
616
617=cut