1CMS(1)                              OpenSSL                             CMS(1)
2
3
4

NAME

6       openssl-cms, cms - CMS utility
7

SYNOPSIS

9       openssl cms [-help] [-encrypt] [-decrypt] [-sign] [-verify] [-cmsout]
10       [-resign] [-data_create] [-data_out] [-digest_create] [-digest_verify]
11       [-compress] [-uncompress] [-EncryptedData_encrypt] [-sign_receipt]
12       [-verify_receipt receipt] [-in filename] [-inform SMIME|PEM|DER]
13       [-rctform SMIME|PEM|DER] [-out filename] [-outform SMIME|PEM|DER]
14       [-stream -indef -noindef] [-noindef] [-content filename] [-text]
15       [-noout] [-print] [-CAfile file] [-CApath dir] [-no-CAfile]
16       [-no-CApath] [-attime timestamp] [-check_ss_sig] [-crl_check]
17       [-crl_check_all] [-explicit_policy] [-extended_crl] [-ignore_critical]
18       [-inhibit_any] [-inhibit_map] [-no_check_time] [-partial_chain]
19       [-policy arg] [-policy_check] [-policy_print] [-purpose purpose]
20       [-suiteB_128] [-suiteB_128_only] [-suiteB_192] [-trusted_first]
21       [-no_alt_chains] [-use_deltas] [-auth_level num] [-verify_depth num]
22       [-verify_email email] [-verify_hostname hostname] [-verify_ip ip]
23       [-verify_name name] [-x509_strict] [-md digest] [-cipher] [-nointern]
24       [-noverify] [-nocerts] [-noattr] [-nosmimecap] [-binary] [-crlfeol]
25       [-asciicrlf] [-nodetach] [-certfile file] [-certsout file] [-signer
26       file] [-recip file] [-keyid] [-receipt_request_all]
27       [-receipt_request_first] [-receipt_request_from emailaddress]
28       [-receipt_request_to emailaddress] [-receipt_request_print] [-secretkey
29       key] [-secretkeyid id] [-econtent_type type] [-inkey file] [-keyopt
30       name:parameter] [-passin arg] [-rand file...]  [-writerand file]
31       [cert.pem...]  [-to addr] [-from addr] [-subject subj] [cert.pem]...
32

DESCRIPTION

34       The cms command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign
35       and verify, compress and uncompress S/MIME messages.
36

OPTIONS

38       There are fourteen operation options that set the type of operation to
39       be performed. The meaning of the other options varies according to the
40       operation type.
41
42       -help
43           Print out a usage message.
44
45       -encrypt
46           Encrypt mail for the given recipient certificates. Input file is
47           the message to be encrypted. The output file is the encrypted mail
48           in MIME format. The actual CMS type is <B>EnvelopedData<B>.
49
50           Note that no revocation check is done for the recipient cert, so if
51           that key has been compromised, others may be able to decrypt the
52           text.
53
54       -decrypt
55           Decrypt mail using the supplied certificate and private key.
56           Expects an encrypted mail message in MIME format for the input
57           file. The decrypted mail is written to the output file.
58
59       -debug_decrypt
60           This option sets the CMS_DEBUG_DECRYPT flag. This option should be
61           used with caution: see the notes section below.
62
63       -sign
64           Sign mail using the supplied certificate and private key. Input
65           file is the message to be signed. The signed message in MIME format
66           is written to the output file.
67
68       -verify
69           Verify signed mail. Expects a signed mail message on input and
70           outputs the signed data. Both clear text and opaque signing is
71           supported.
72
73       -cmsout
74           Takes an input message and writes out a PEM encoded CMS structure.
75
76       -resign
77           Resign a message: take an existing message and one or more new
78           signers.
79
80       -data_create
81           Create a CMS Data type.
82
83       -data_out
84           Data type and output the content.
85
86       -digest_create
87           Create a CMS DigestedData type.
88
89       -digest_verify
90           Verify a CMS DigestedData type and output the content.
91
92       -compress
93           Create a CMS CompressedData type. OpenSSL must be compiled with
94           zlib support for this option to work, otherwise it will output an
95           error.
96
97       -uncompress
98           Uncompress a CMS CompressedData type and output the content.
99           OpenSSL must be compiled with zlib support for this option to work,
100           otherwise it will output an error.
101
102       -EncryptedData_encrypt
103           Encrypt content using supplied symmetric key and algorithm using a
104           CMS EncryptedData type and output the content.
105
106       -sign_receipt
107           Generate and output a signed receipt for the supplied message. The
108           input message must contain a signed receipt request. Functionality
109           is otherwise similar to the -sign operation.
110
111       -verify_receipt receipt
112           Verify a signed receipt in filename receipt. The input message must
113           contain the original receipt request. Functionality is otherwise
114           similar to the -verify operation.
115
116       -in filename
117           The input message to be encrypted or signed or the message to be
118           decrypted or verified.
119
120       -inform SMIME|PEM|DER
121           This specifies the input format for the CMS structure. The default
122           is SMIME which reads an S/MIME format message. PEM and DER format
123           change this to expect PEM and DER format CMS structures instead.
124           This currently only affects the input format of the CMS structure,
125           if no CMS structure is being input (for example with -encrypt or
126           -sign) this option has no effect.
127
128       -rctform SMIME|PEM|DER
129           Specify the format for a signed receipt for use with the
130           -receipt_verify operation.
131
132       -out filename
133           The message text that has been decrypted or verified or the output
134           MIME format message that has been signed or verified.
135
136       -outform SMIME|PEM|DER
137           This specifies the output format for the CMS structure. The default
138           is SMIME which writes an S/MIME format message. PEM and DER format
139           change this to write PEM and DER format CMS structures instead.
140           This currently only affects the output format of the CMS structure,
141           if no CMS structure is being output (for example with -verify or
142           -decrypt) this option has no effect.
143
144       -stream -indef -noindef
145           The -stream and -indef options are equivalent and enable streaming
146           I/O for encoding operations. This permits single pass processing of
147           data without the need to hold the entire contents in memory,
148           potentially supporting very large files. Streaming is automatically
149           set for S/MIME signing with detached data if the output format is
150           SMIME it is currently off by default for all other operations.
151
152       -noindef
153           Disable streaming I/O where it would produce and indefinite length
154           constructed encoding. This option currently has no effect. In
155           future streaming will be enabled by default on all relevant
156           operations and this option will disable it.
157
158       -content filename
159           This specifies a file containing the detached content, this is only
160           useful with the -verify command. This is only usable if the CMS
161           structure is using the detached signature form where the content is
162           not included. This option will override any content if the input
163           format is S/MIME and it uses the multipart/signed MIME content
164           type.
165
166       -text
167           This option adds plain text (text/plain) MIME headers to the
168           supplied message if encrypting or signing. If decrypting or
169           verifying it strips off text headers: if the decrypted or verified
170           message is not of MIME type text/plain then an error occurs.
171
172       -noout
173           For the -cmsout operation do not output the parsed CMS structure.
174           This is useful when combined with the -print option or if the
175           syntax of the CMS structure is being checked.
176
177       -print
178           For the -cmsout operation print out all fields of the CMS
179           structure. This is mainly useful for testing purposes.
180
181       -CAfile file
182           A file containing trusted CA certificates, only used with -verify.
183
184       -CApath dir
185           A directory containing trusted CA certificates, only used with
186           -verify. This directory must be a standard certificate directory:
187           that is a hash of each subject name (using x509 -hash) should be
188           linked to each certificate.
189
190       -no-CAfile
191           Do not load the trusted CA certificates from the default file
192           location
193
194       -no-CApath
195           Do not load the trusted CA certificates from the default directory
196           location
197
198       -md digest
199           Digest algorithm to use when signing or resigning. If not present
200           then the default digest algorithm for the signing key will be used
201           (usually SHA1).
202
203       -cipher
204           The encryption algorithm to use. For example triple DES (168 bits)
205           - -des3 or 256 bit AES - -aes256. Any standard algorithm name (as
206           used by the EVP_get_cipherbyname() function) can also be used
207           preceded by a dash, for example -aes-128-cbc. See enc(1) for a list
208           of ciphers supported by your version of OpenSSL.
209
210           If not specified triple DES is used. Only used with -encrypt and
211           -EncryptedData_create commands.
212
213       -nointern
214           When verifying a message normally certificates (if any) included in
215           the message are searched for the signing certificate. With this
216           option only the certificates specified in the -certfile option are
217           used.  The supplied certificates can still be used as untrusted CAs
218           however.
219
220       -noverify
221           Do not verify the signers certificate of a signed message.
222
223       -nocerts
224           When signing a message the signer's certificate is normally
225           included with this option it is excluded. This will reduce the size
226           of the signed message but the verifier must have a copy of the
227           signers certificate available locally (passed using the -certfile
228           option for example).
229
230       -noattr
231           Normally when a message is signed a set of attributes are included
232           which include the signing time and supported symmetric algorithms.
233           With this option they are not included.
234
235       -nosmimecap
236           Exclude the list of supported algorithms from signed attributes,
237           other options such as signing time and content type are still
238           included.
239
240       -binary
241           Normally the input message is converted to "canonical" format which
242           is effectively using CR and LF as end of line: as required by the
243           S/MIME specification. When this option is present no translation
244           occurs. This is useful when handling binary data which may not be
245           in MIME format.
246
247       -crlfeol
248           Normally the output file uses a single LF as end of line. When this
249           option is present CRLF is used instead.
250
251       -asciicrlf
252           When signing use ASCII CRLF format canonicalisation. This strips
253           trailing whitespace from all lines, deletes trailing blank lines at
254           EOF and sets the encapsulated content type. This option is normally
255           used with detached content and an output signature format of DER.
256           This option is not normally needed when verifying as it is enabled
257           automatically if the encapsulated content format is detected.
258
259       -nodetach
260           When signing a message use opaque signing: this form is more
261           resistant to translation by mail relays but it cannot be read by
262           mail agents that do not support S/MIME.  Without this option
263           cleartext signing with the MIME type multipart/signed is used.
264
265       -certfile file
266           Allows additional certificates to be specified. When signing these
267           will be included with the message. When verifying these will be
268           searched for the signers certificates. The certificates should be
269           in PEM format.
270
271       -certsout file
272           Any certificates contained in the message are written to file.
273
274       -signer file
275           A signing certificate when signing or resigning a message, this
276           option can be used multiple times if more than one signer is
277           required. If a message is being verified then the signers
278           certificates will be written to this file if the verification was
279           successful.
280
281       -recip file
282           When decrypting a message this specifies the recipients
283           certificate. The certificate must match one of the recipients of
284           the message or an error occurs.
285
286           When encrypting a message this option may be used multiple times to
287           specify each recipient. This form must be used if customised
288           parameters are required (for example to specify RSA-OAEP).
289
290           Only certificates carrying RSA, Diffie-Hellman or EC keys are
291           supported by this option.
292
293       -keyid
294           Use subject key identifier to identify certificates instead of
295           issuer name and serial number. The supplied certificate must
296           include a subject key identifier extension. Supported by -sign and
297           -encrypt options.
298
299       -receipt_request_all, -receipt_request_first
300           For -sign option include a signed receipt request. Indicate
301           requests should be provided by all recipient or first tier
302           recipients (those mailed directly and not from a mailing list).
303           Ignored it -receipt_request_from is included.
304
305       -receipt_request_from emailaddress
306           For -sign option include a signed receipt request. Add an explicit
307           email address where receipts should be supplied.
308
309       -receipt_request_to emailaddress
310           Add an explicit email address where signed receipts should be sent
311           to. This option must but supplied if a signed receipt it requested.
312
313       -receipt_request_print
314           For the -verify operation print out the contents of any signed
315           receipt requests.
316
317       -secretkey key
318           Specify symmetric key to use. The key must be supplied in hex
319           format and be consistent with the algorithm used. Supported by the
320           -EncryptedData_encrypt -EncryptedData_decrypt, -encrypt and
321           -decrypt options. When used with -encrypt or -decrypt the supplied
322           key is used to wrap or unwrap the content encryption key using an
323           AES key in the KEKRecipientInfo type.
324
325       -secretkeyid id
326           The key identifier for the supplied symmetric key for
327           KEKRecipientInfo type.  This option must be present if the
328           -secretkey option is used with -encrypt. With -decrypt operations
329           the id is used to locate the relevant key if it is not supplied
330           then an attempt is used to decrypt any KEKRecipientInfo structures.
331
332       -econtent_type type
333           Set the encapsulated content type to type if not supplied the Data
334           type is used. The type argument can be any valid OID name in either
335           text or numerical format.
336
337       -inkey file
338           The private key to use when signing or decrypting. This must match
339           the corresponding certificate. If this option is not specified then
340           the private key must be included in the certificate file specified
341           with the -recip or -signer file. When signing this option can be
342           used multiple times to specify successive keys.
343
344       -keyopt name:opt
345           For signing and encryption this option can be used multiple times
346           to set customised parameters for the preceding key or certificate.
347           It can currently be used to set RSA-PSS for signing, RSA-OAEP for
348           encryption or to modify default parameters for ECDH.
349
350       -passin arg
351           The private key password source. For more information about the
352           format of arg see "Pass Phrase Options" in openssl(1).
353
354       -rand file...
355           A file or files containing random data used to seed the random
356           number generator.  Multiple files can be specified separated by an
357           OS-dependent character.  The separator is ; for MS-Windows, , for
358           OpenVMS, and : for all others.
359
360       [-writerand file]
361           Writes random data to the specified file upon exit.  This can be
362           used with a subsequent -rand flag.
363
364       cert.pem...
365           One or more certificates of message recipients: used when
366           encrypting a message.
367
368       -to, -from, -subject
369           The relevant mail headers. These are included outside the signed
370           portion of a message so they may be included manually. If signing
371           then many S/MIME mail clients check the signers certificate's email
372           address matches that specified in the From: address.
373
374       -attime, -check_ss_sig, -crl_check, -crl_check_all, -explicit_policy,
375       -extended_crl, -ignore_critical, -inhibit_any, -inhibit_map,
376       -no_alt_chains, -no_check_time, -partial_chain, -policy, -policy_check,
377       -policy_print, -purpose, -suiteB_128, -suiteB_128_only, -suiteB_192,
378       -trusted_first, -use_deltas, -auth_level, -verify_depth, -verify_email,
379       -verify_hostname, -verify_ip, -verify_name, -x509_strict
380           Set various certificate chain validation options. See the verify(1)
381           manual page for details.
382

NOTES

384       The MIME message must be sent without any blank lines between the
385       headers and the output. Some mail programs will automatically add a
386       blank line. Piping the mail directly to sendmail is one way to achieve
387       the correct format.
388
389       The supplied message to be signed or encrypted must include the
390       necessary MIME headers or many S/MIME clients won't display it properly
391       (if at all). You can use the -text option to automatically add plain
392       text headers.
393
394       A "signed and encrypted" message is one where a signed message is then
395       encrypted. This can be produced by encrypting an already signed
396       message: see the examples section.
397
398       This version of the program only allows one signer per message but it
399       will verify multiple signers on received messages. Some S/MIME clients
400       choke if a message contains multiple signers. It is possible to sign
401       messages "in parallel" by signing an already signed message.
402
403       The options -encrypt and -decrypt reflect common usage in S/MIME
404       clients. Strictly speaking these process CMS enveloped data: CMS
405       encrypted data is used for other purposes.
406
407       The -resign option uses an existing message digest when adding a new
408       signer. This means that attributes must be present in at least one
409       existing signer using the same message digest or this operation will
410       fail.
411
412       The -stream and -indef options enable streaming I/O support.  As a
413       result the encoding is BER using indefinite length constructed encoding
414       and no longer DER. Streaming is supported for the -encrypt operation
415       and the -sign operation if the content is not detached.
416
417       Streaming is always used for the -sign operation with detached data but
418       since the content is no longer part of the CMS structure the encoding
419       remains DER.
420
421       If the -decrypt option is used without a recipient certificate then an
422       attempt is made to locate the recipient by trying each potential
423       recipient in turn using the supplied private key. To thwart the MMA
424       attack (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all
425       recipients are tried whether they succeed or not and if no recipients
426       match the message is "decrypted" using a random key which will
427       typically output garbage.  The -debug_decrypt option can be used to
428       disable the MMA attack protection and return an error if no recipient
429       can be found: this option should be used with caution. For a fuller
430       description see CMS_decrypt(3)).
431

EXIT CODES

433       0   The operation was completely successfully.
434
435       1   An error occurred parsing the command options.
436
437       2   One of the input files could not be read.
438
439       3   An error occurred creating the CMS file or when reading the MIME
440           message.
441
442       4   An error occurred decrypting or verifying the message.
443
444       5   The message was verified correctly but an error occurred writing
445           out the signers certificates.
446

COMPATIBILITY WITH PKCS#7 format.

448       The smime utility can only process the older PKCS#7 format. The cms
449       utility supports Cryptographic Message Syntax format. Use of some
450       features will result in messages which cannot be processed by
451       applications which only support the older format. These are detailed
452       below.
453
454       The use of the -keyid option with -sign or -encrypt.
455
456       The -outform PEM option uses different headers.
457
458       The -compress option.
459
460       The -secretkey option when used with -encrypt.
461
462       The use of PSS with -sign.
463
464       The use of OAEP or non-RSA keys with -encrypt.
465
466       Additionally the -EncryptedData_create and -data_create type cannot be
467       processed by the older smime command.
468

EXAMPLES

470       Create a cleartext signed message:
471
472        openssl cms -sign -in message.txt -text -out mail.msg \
473               -signer mycert.pem
474
475       Create an opaque signed message
476
477        openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
478               -signer mycert.pem
479
480       Create a signed message, include some additional certificates and read
481       the private key from another file:
482
483        openssl cms -sign -in in.txt -text -out mail.msg \
484               -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
485
486       Create a signed message with two signers, use key identifier:
487
488        openssl cms -sign -in message.txt -text -out mail.msg \
489               -signer mycert.pem -signer othercert.pem -keyid
490
491       Send a signed message under Unix directly to sendmail, including
492       headers:
493
494        openssl cms -sign -in in.txt -text -signer mycert.pem \
495               -from steve@openssl.org -to someone@somewhere \
496               -subject "Signed message" | sendmail someone@somewhere
497
498       Verify a message and extract the signer's certificate if successful:
499
500        openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
501
502       Send encrypted mail using triple DES:
503
504        openssl cms -encrypt -in in.txt -from steve@openssl.org \
505               -to someone@somewhere -subject "Encrypted message" \
506               -des3 user.pem -out mail.msg
507
508       Sign and encrypt mail:
509
510        openssl cms -sign -in ml.txt -signer my.pem -text \
511               | openssl cms -encrypt -out mail.msg \
512               -from steve@openssl.org -to someone@somewhere \
513               -subject "Signed and Encrypted message" -des3 user.pem
514
515       Note: the encryption command does not include the -text option because
516       the message being encrypted already has MIME headers.
517
518       Decrypt mail:
519
520        openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
521
522       The output from Netscape form signing is a PKCS#7 structure with the
523       detached signature format. You can use this program to verify the
524       signature by line wrapping the base64 encoded structure and surrounding
525       it with:
526
527        -----BEGIN PKCS7-----
528        -----END PKCS7-----
529
530       and using the command,
531
532        openssl cms -verify -inform PEM -in signature.pem -content content.txt
533
534       alternatively you can base64 decode the signature and use
535
536        openssl cms -verify -inform DER -in signature.der -content content.txt
537
538       Create an encrypted message using 128 bit Camellia:
539
540        openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
541
542       Add a signer to an existing message:
543
544        openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
545
546       Sign mail using RSA-PSS:
547
548        openssl cms -sign -in message.txt -text -out mail.msg \
549               -signer mycert.pem -keyopt rsa_padding_mode:pss
550
551       Create encrypted mail using RSA-OAEP:
552
553        openssl cms -encrypt -in plain.txt -out mail.msg \
554               -recip cert.pem -keyopt rsa_padding_mode:oaep
555
556       Use SHA256 KDF with an ECDH certificate:
557
558        openssl cms -encrypt -in plain.txt -out mail.msg \
559               -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
560

BUGS

562       The MIME parser isn't very clever: it seems to handle most messages
563       that I've thrown at it but it may choke on others.
564
565       The code currently will only write out the signer's certificate to a
566       file: if the signer has a separate encryption certificate this must be
567       manually extracted. There should be some heuristic that determines the
568       correct encryption certificate.
569
570       Ideally a database should be maintained of a certificates for each
571       email address.
572
573       The code doesn't currently take note of the permitted symmetric
574       encryption algorithms as supplied in the SMIMECapabilities signed
575       attribute. this means the user has to manually include the correct
576       encryption algorithm. It should store the list of permitted ciphers in
577       a database and only use those.
578
579       No revocation checking is done on the signer's certificate.
580

HISTORY

582       The use of multiple -signer options and the -resign command were first
583       added in OpenSSL 1.0.0.
584
585       The keyopt option was added in OpenSSL 1.0.2.
586
587       Support for RSA-OAEP and RSA-PSS was added in OpenSSL 1.0.2.
588
589       The use of non-RSA keys with -encrypt and -decrypt was added in OpenSSL
590       1.0.2.
591
592       The -no_alt_chains option was added in OpenSSL 1.0.2b.
593
595       Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved.
596
597       Licensed under the OpenSSL license (the "License").  You may not use
598       this file except in compliance with the License.  You can obtain a copy
599       in the file LICENSE in the source distribution or at
600       <https://www.openssl.org/source/license.html>.
601
602
603
6041.1.1k                            2021-03-26                            CMS(1)
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