5 openssl-cms - CMS utility
24 [B<-EncryptedData_encrypt>]
26 [B<-verify_receipt receipt>]
28 [B<-inform SMIME|PEM|DER>]
29 [B<-rctform SMIME|PEM|DER>]
31 [B<-outform SMIME|PEM|DER>]
32 [B<-stream -indef -noindef>]
34 [B<-content filename>]
42 [B<-attime timestamp>]
64 [B<-verify_depth num>]
65 [B<-verify_email email>]
66 [B<-verify_hostname hostname>]
68 [B<-verify_name name>]
86 [B<-receipt_request_all>]
87 [B<-receipt_request_first>]
88 [B<-receipt_request_from emailaddress>]
89 [B<-receipt_request_to emailaddress>]
90 [B<-receipt_request_print>]
93 [B<-econtent_type type>]
95 [B<-keyopt name:parameter>]
107 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
108 verify, compress and uncompress S/MIME messages.
112 There are fourteen operation options that set the type of operation to be
113 performed. The meaning of the other options varies according to the operation
120 Print out a usage message.
124 Encrypt mail for the given recipient certificates. Input file is the message
125 to be encrypted. The output file is the encrypted mail in MIME format. The
126 actual CMS type is <B>EnvelopedData<B>.
128 Note that no revocation check is done for the recipient cert, so if that
129 key has been compromised, others may be able to decrypt the text.
133 Decrypt mail using the supplied certificate and private key. Expects an
134 encrypted mail message in MIME format for the input file. The decrypted mail
135 is written to the output file.
137 =item B<-debug_decrypt>
139 This option sets the B<CMS_DEBUG_DECRYPT> flag. This option should be used
140 with caution: see the notes section below.
144 Sign mail using the supplied certificate and private key. Input file is
145 the message to be signed. The signed message in MIME format is written
150 Verify signed mail. Expects a signed mail message on input and outputs
151 the signed data. Both clear text and opaque signing is supported.
155 Takes an input message and writes out a PEM encoded CMS structure.
159 Resign a message: take an existing message and one or more new signers.
163 Add an ESS signing-certificate or ESS signing-certificate-v2 signed-attribute to the SignerInfo, in order to make
164 the signature comply with the requirements for a CAdES Basic Electronic Signature (CAdES-BES). See the NOTES
165 section for more details.
167 =item B<-data_create>
169 Create a CMS B<Data> type.
173 B<Data> type and output the content.
175 =item B<-digest_create>
177 Create a CMS B<DigestedData> type.
179 =item B<-digest_verify>
181 Verify a CMS B<DigestedData> type and output the content.
185 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
186 support for this option to work, otherwise it will output an error.
190 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
191 compiled with B<zlib> support for this option to work, otherwise it will
194 =item B<-EncryptedData_encrypt>
196 Encrypt content using supplied symmetric key and algorithm using a CMS
197 B<EncryptedData> type and output the content.
199 =item B<-sign_receipt>
201 Generate and output a signed receipt for the supplied message. The input
202 message B<must> contain a signed receipt request. Functionality is otherwise
203 similar to the B<-sign> operation.
205 =item B<-verify_receipt receipt>
207 Verify a signed receipt in filename B<receipt>. The input message B<must>
208 contain the original receipt request. Functionality is otherwise similar
209 to the B<-verify> operation.
211 =item B<-in filename>
213 The input message to be encrypted or signed or the message to be decrypted
216 =item B<-inform SMIME|PEM|DER>
218 This specifies the input format for the CMS structure. The default
219 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
220 format change this to expect PEM and DER format CMS structures
221 instead. This currently only affects the input format of the CMS
222 structure, if no CMS structure is being input (for example with
223 B<-encrypt> or B<-sign>) this option has no effect.
225 =item B<-rctform SMIME|PEM|DER>
227 Specify the format for a signed receipt for use with the B<-receipt_verify>
230 =item B<-out filename>
232 The message text that has been decrypted or verified or the output MIME
233 format message that has been signed or verified.
235 =item B<-outform SMIME|PEM|DER>
237 This specifies the output format for the CMS structure. The default
238 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
239 format change this to write PEM and DER format CMS structures
240 instead. This currently only affects the output format of the CMS
241 structure, if no CMS structure is being output (for example with
242 B<-verify> or B<-decrypt>) this option has no effect.
244 =item B<-stream -indef -noindef>
246 The B<-stream> and B<-indef> options are equivalent and enable streaming I/O
247 for encoding operations. This permits single pass processing of data without
248 the need to hold the entire contents in memory, potentially supporting very
249 large files. Streaming is automatically set for S/MIME signing with detached
250 data if the output format is B<SMIME> it is currently off by default for all
255 Disable streaming I/O where it would produce and indefinite length constructed
256 encoding. This option currently has no effect. In future streaming will be
257 enabled by default on all relevant operations and this option will disable it.
259 =item B<-content filename>
261 This specifies a file containing the detached content, this is only
262 useful with the B<-verify> command. This is only usable if the CMS
263 structure is using the detached signature form where the content is
264 not included. This option will override any content if the input format
265 is S/MIME and it uses the multipart/signed MIME content type.
269 This option adds plain text (text/plain) MIME headers to the supplied
270 message if encrypting or signing. If decrypting or verifying it strips
271 off text headers: if the decrypted or verified message is not of MIME
272 type text/plain then an error occurs.
276 For the B<-cmsout> operation do not output the parsed CMS structure. This
277 is useful when combined with the B<-print> option or if the syntax of the CMS
278 structure is being checked.
282 For the B<-cmsout> operation print out all fields of the CMS structure. This
283 is mainly useful for testing purposes.
285 =item B<-CAfile file>
287 A file containing trusted CA certificates, only used with B<-verify>.
291 A directory containing trusted CA certificates, only used with
292 B<-verify>. This directory must be a standard certificate directory: that
293 is a hash of each subject name (using B<x509 -hash>) should be linked
298 Do not load the trusted CA certificates from the default file location
302 Do not load the trusted CA certificates from the default directory location
306 Digest algorithm to use when signing or resigning. If not present then the
307 default digest algorithm for the signing key will be used (usually SHA1).
311 The encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
312 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
313 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
314 example B<-aes-128-cbc>. See L<enc(1)> for a list of ciphers
315 supported by your version of OpenSSL.
317 If not specified triple DES is used. Only used with B<-encrypt> and
318 B<-EncryptedData_create> commands.
322 When verifying a message normally certificates (if any) included in
323 the message are searched for the signing certificate. With this option
324 only the certificates specified in the B<-certfile> option are used.
325 The supplied certificates can still be used as untrusted CAs however.
329 Do not verify the signers certificate of a signed message.
333 When signing a message the signer's certificate is normally included
334 with this option it is excluded. This will reduce the size of the
335 signed message but the verifier must have a copy of the signers certificate
336 available locally (passed using the B<-certfile> option for example).
340 Normally when a message is signed a set of attributes are included which
341 include the signing time and supported symmetric algorithms. With this
342 option they are not included.
346 Exclude the list of supported algorithms from signed attributes, other options
347 such as signing time and content type are still included.
351 Normally the input message is converted to "canonical" format which is
352 effectively using CR and LF as end of line: as required by the S/MIME
353 specification. When this option is present no translation occurs. This
354 is useful when handling binary data which may not be in MIME format.
358 Normally the output file uses a single B<LF> as end of line. When this
359 option is present B<CRLF> is used instead.
363 When signing use ASCII CRLF format canonicalisation. This strips trailing
364 whitespace from all lines, deletes trailing blank lines at EOF and sets
365 the encapsulated content type. This option is normally used with detached
366 content and an output signature format of DER. This option is not normally
367 needed when verifying as it is enabled automatically if the encapsulated
368 content format is detected.
372 When signing a message use opaque signing: this form is more resistant
373 to translation by mail relays but it cannot be read by mail agents that
374 do not support S/MIME. Without this option cleartext signing with
375 the MIME type multipart/signed is used.
377 =item B<-certfile file>
379 Allows additional certificates to be specified. When signing these will
380 be included with the message. When verifying these will be searched for
381 the signers certificates. The certificates should be in PEM format.
383 =item B<-certsout file>
385 Any certificates contained in the message are written to B<file>.
387 =item B<-signer file>
389 A signing certificate when signing or resigning a message, this option can be
390 used multiple times if more than one signer is required. If a message is being
391 verified then the signers certificates will be written to this file if the
392 verification was successful.
396 When decrypting a message this specifies the recipients certificate. The
397 certificate must match one of the recipients of the message or an error
400 When encrypting a message this option may be used multiple times to specify
401 each recipient. This form B<must> be used if customised parameters are
402 required (for example to specify RSA-OAEP).
404 Only certificates carrying RSA, Diffie-Hellman or EC keys are supported by this
409 Use subject key identifier to identify certificates instead of issuer name and
410 serial number. The supplied certificate B<must> include a subject key
411 identifier extension. Supported by B<-sign> and B<-encrypt> options.
413 =item B<-receipt_request_all>, B<-receipt_request_first>
415 For B<-sign> option include a signed receipt request. Indicate requests should
416 be provided by all recipient or first tier recipients (those mailed directly
417 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
419 =item B<-receipt_request_from emailaddress>
421 For B<-sign> option include a signed receipt request. Add an explicit email
422 address where receipts should be supplied.
424 =item B<-receipt_request_to emailaddress>
426 Add an explicit email address where signed receipts should be sent to. This
427 option B<must> but supplied if a signed receipt it requested.
429 =item B<-receipt_request_print>
431 For the B<-verify> operation print out the contents of any signed receipt
434 =item B<-secretkey key>
436 Specify symmetric key to use. The key must be supplied in hex format and be
437 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
438 B<-EncryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
439 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
440 content encryption key using an AES key in the B<KEKRecipientInfo> type.
442 =item B<-secretkeyid id>
444 The key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
445 This option B<must> be present if the B<-secretkey> option is used with
446 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
447 relevant key if it is not supplied then an attempt is used to decrypt any
448 B<KEKRecipientInfo> structures.
450 =item B<-econtent_type type>
452 Set the encapsulated content type to B<type> if not supplied the B<Data> type
453 is used. The B<type> argument can be any valid OID name in either text or
458 The private key to use when signing or decrypting. This must match the
459 corresponding certificate. If this option is not specified then the
460 private key must be included in the certificate file specified with
461 the B<-recip> or B<-signer> file. When signing this option can be used
462 multiple times to specify successive keys.
464 =item B<-keyopt name:opt>
466 For signing and encryption this option can be used multiple times to
467 set customised parameters for the preceding key or certificate. It can
468 currently be used to set RSA-PSS for signing, RSA-OAEP for encryption
469 or to modify default parameters for ECDH.
473 The private key password source. For more information about the format of B<arg>
474 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
476 =item B<-rand file...>
478 A file or files containing random data used to seed the random number
480 Multiple files can be specified separated by an OS-dependent character.
481 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
484 =item [B<-writerand file>]
486 Writes random data to the specified I<file> upon exit.
487 This can be used with a subsequent B<-rand> flag.
491 One or more certificates of message recipients: used when encrypting
494 =item B<-to, -from, -subject>
496 The relevant mail headers. These are included outside the signed
497 portion of a message so they may be included manually. If signing
498 then many S/MIME mail clients check the signers certificate's email
499 address matches that specified in the From: address.
501 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
502 B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
503 B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
504 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
505 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
506 B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
507 B<-verify_ip>, B<-verify_name>, B<-x509_strict>
509 Set various certificate chain validation options. See the
510 L<verify(1)> manual page for details.
516 The MIME message must be sent without any blank lines between the
517 headers and the output. Some mail programs will automatically add
518 a blank line. Piping the mail directly to sendmail is one way to
519 achieve the correct format.
521 The supplied message to be signed or encrypted must include the
522 necessary MIME headers or many S/MIME clients won't display it
523 properly (if at all). You can use the B<-text> option to automatically
524 add plain text headers.
526 A "signed and encrypted" message is one where a signed message is
527 then encrypted. This can be produced by encrypting an already signed
528 message: see the examples section.
530 This version of the program only allows one signer per message but it
531 will verify multiple signers on received messages. Some S/MIME clients
532 choke if a message contains multiple signers. It is possible to sign
533 messages "in parallel" by signing an already signed message.
535 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
536 clients. Strictly speaking these process CMS enveloped data: CMS
537 encrypted data is used for other purposes.
539 The B<-resign> option uses an existing message digest when adding a new
540 signer. This means that attributes must be present in at least one existing
541 signer using the same message digest or this operation will fail.
543 The B<-stream> and B<-indef> options enable streaming I/O support.
544 As a result the encoding is BER using indefinite length constructed encoding
545 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
546 B<-sign> operation if the content is not detached.
548 Streaming is always used for the B<-sign> operation with detached data but
549 since the content is no longer part of the CMS structure the encoding
552 If the B<-decrypt> option is used without a recipient certificate then an
553 attempt is made to locate the recipient by trying each potential recipient
554 in turn using the supplied private key. To thwart the MMA attack
555 (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all recipients are
556 tried whether they succeed or not and if no recipients match the message
557 is "decrypted" using a random key which will typically output garbage.
558 The B<-debug_decrypt> option can be used to disable the MMA attack protection
559 and return an error if no recipient can be found: this option should be used
560 with caution. For a fuller description see L<CMS_decrypt(3)>).
562 =head1 CAdES Basic Electronic Signature (CAdES-BES)
564 A CAdES Basic Electronic Signature (CAdES-BES), as defined in the European Standard ETSI EN 319 122-1 V1.1.1, contains:
570 The signed user data as defined in CMS (RFC 3852);
574 Content-type of the EncapsulatedContentInfo value being signed;
578 Message-digest of the eContent OCTET STRING within encapContentInfo being signed;
582 An ESS signing-certificate or ESS signing-certificate-v2 attribute, as defined in Enhanced Security Services (ESS), RFC 2634 and RFC 5035.
583 An ESS signing-certificate attribute only allows for the use of SHA-1 as a digest algorithm.
584 An ESS signing-certificate-v2 attribute allows for the use of any digest algorithm.
588 The digital signature value computed on the user data and, when present, on the signed attributes.
590 Note that currently the B<-cades> option applies only to the B<-sign> operation and is ignored during
591 the B<-verify> operation, i.e. the signing certification is not checked during the verification process.
592 This feature might be added in a future version.
602 The operation was completely successfully.
606 An error occurred parsing the command options.
610 One of the input files could not be read.
614 An error occurred creating the CMS file or when reading the MIME
619 An error occurred decrypting or verifying the message.
623 The message was verified correctly but an error occurred writing out
624 the signers certificates.
628 =head1 COMPATIBILITY WITH PKCS#7 format.
630 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
631 utility supports Cryptographic Message Syntax format. Use of some features
632 will result in messages which cannot be processed by applications which only
633 support the older format. These are detailed below.
635 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
637 The B<-outform PEM> option uses different headers.
639 The B<-compress> option.
641 The B<-secretkey> option when used with B<-encrypt>.
643 The use of PSS with B<-sign>.
645 The use of OAEP or non-RSA keys with B<-encrypt>.
647 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
648 be processed by the older B<smime> command.
652 Create a cleartext signed message:
654 openssl cms -sign -in message.txt -text -out mail.msg \
657 Create an opaque signed message
659 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
662 Create a signed message, include some additional certificates and
663 read the private key from another file:
665 openssl cms -sign -in in.txt -text -out mail.msg \
666 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
668 Create a signed message with two signers, use key identifier:
670 openssl cms -sign -in message.txt -text -out mail.msg \
671 -signer mycert.pem -signer othercert.pem -keyid
673 Send a signed message under Unix directly to sendmail, including headers:
675 openssl cms -sign -in in.txt -text -signer mycert.pem \
676 -from steve@openssl.org -to someone@somewhere \
677 -subject "Signed message" | sendmail someone@somewhere
679 Verify a message and extract the signer's certificate if successful:
681 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
683 Send encrypted mail using triple DES:
685 openssl cms -encrypt -in in.txt -from steve@openssl.org \
686 -to someone@somewhere -subject "Encrypted message" \
687 -des3 user.pem -out mail.msg
689 Sign and encrypt mail:
691 openssl cms -sign -in ml.txt -signer my.pem -text \
692 | openssl cms -encrypt -out mail.msg \
693 -from steve@openssl.org -to someone@somewhere \
694 -subject "Signed and Encrypted message" -des3 user.pem
696 Note: the encryption command does not include the B<-text> option because the
697 message being encrypted already has MIME headers.
701 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
703 The output from Netscape form signing is a PKCS#7 structure with the
704 detached signature format. You can use this program to verify the
705 signature by line wrapping the base64 encoded structure and surrounding
708 -----BEGIN PKCS7-----
711 and using the command,
713 openssl cms -verify -inform PEM -in signature.pem -content content.txt
715 alternatively you can base64 decode the signature and use
717 openssl cms -verify -inform DER -in signature.der -content content.txt
719 Create an encrypted message using 128 bit Camellia:
721 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
723 Add a signer to an existing message:
725 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
727 Sign mail using RSA-PSS:
729 openssl cms -sign -in message.txt -text -out mail.msg \
730 -signer mycert.pem -keyopt rsa_padding_mode:pss
732 Create encrypted mail using RSA-OAEP:
734 openssl cms -encrypt -in plain.txt -out mail.msg \
735 -recip cert.pem -keyopt rsa_padding_mode:oaep
737 Use SHA256 KDF with an ECDH certificate:
739 openssl cms -encrypt -in plain.txt -out mail.msg \
740 -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
744 The MIME parser isn't very clever: it seems to handle most messages that I've
745 thrown at it but it may choke on others.
747 The code currently will only write out the signer's certificate to a file: if
748 the signer has a separate encryption certificate this must be manually
749 extracted. There should be some heuristic that determines the correct
750 encryption certificate.
752 Ideally a database should be maintained of a certificates for each email
755 The code doesn't currently take note of the permitted symmetric encryption
756 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
757 user has to manually include the correct encryption algorithm. It should store
758 the list of permitted ciphers in a database and only use those.
760 No revocation checking is done on the signer's certificate.
764 The use of multiple B<-signer> options and the B<-resign> command were first
765 added in OpenSSL 1.0.0.
767 The B<keyopt> option was added in OpenSSL 1.0.2.
769 Support for RSA-OAEP and RSA-PSS was added in OpenSSL 1.0.2.
771 The use of non-RSA keys with B<-encrypt> and B<-decrypt>
772 was added in OpenSSL 1.0.2.
774 The -no_alt_chains option was added in OpenSSL 1.0.2b.
778 Copyright 2008-2019 The OpenSSL Project Authors. All Rights Reserved.
780 Licensed under the Apache License 2.0 (the "License"). You may not use
781 this file except in compliance with the License. You can obtain a copy
782 in the file LICENSE in the source distribution or at
783 L<https://www.openssl.org/source/license.html>.