2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
6 openssl-cms - CMS command
17 {- $OpenSSL::safe::opt_config_synopsis -}
27 [B<-verify_receipt> I<receipt>]
28 [B<-digest> I<digest>]
33 [B<-EncryptedData_encrypt>]
34 [B<-EncryptedData_decrypt>]
41 [B<-inform> B<DER>|B<PEM>|B<SMIME>]
42 [B<-outform> B<DER>|B<PEM>|B<SMIME>]
43 [B<-rctform> B<DER>|B<PEM>|B<SMIME>]
51 Keys and password options:
53 [B<-pwri_password> I<password>]
54 [B<-secretkey> I<key>]
55 [B<-secretkeyid> I<id>]
56 [B<-inkey> I<filename>|I<uri>]
58 [B<-keyopt> I<name>:I<parameter>]
59 [B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>]
60 {- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_provider_synopsis -}
61 {- $OpenSSL::safe::opt_r_synopsis -}
65 [B<-originator> I<file>]
67 [I<recipient-cert> ...]
80 [B<-certfile> I<file>]
86 [B<-receipt_request_all>]
87 [B<-receipt_request_first>]
88 [B<-receipt_request_from> I<emailaddress>]
89 [B<-receipt_request_to> I<emailaddress>]
94 [B<-content> I<filename>]
95 [B<-no_content_verify>]
102 {- $OpenSSL::safe::opt_trust_synopsis -}
107 [B<-econtent_type> I<type>]
109 [B<-certsout> I<file>]
112 [B<-subject> I<subj>]
118 [B<-nameopt> I<option>]
119 [B<-receipt_request_print>]
123 {- $OpenSSL::safe::opt_v_synopsis -}
127 This command handles data in CMS format such as S/MIME v3.1 email messages.
128 It can encrypt, decrypt, sign, verify, compress, uncompress, and print messages.
132 There are a number of operation options that set the type of operation to be
133 performed: encrypt, decrypt, sign, verify, resign, sign_receipt, verify_receipt,
134 digest_create, digest_verify, compress, uncompress,
135 EncryptedData_encrypt, EncryptedData_decrypt, data_create, data_out, or cmsout.
136 The relevance of the other options depends on the operation type
137 and their meaning may vary according to it.
143 Print out a usage message.
147 =head2 General options
151 =item B<-in> I<filename>
153 The input message to be encrypted or signed or the message to be decrypted
156 =item B<-out> I<filename>
158 The message text that has been decrypted or verified or the output MIME
159 format message that has been signed or verified.
161 {- $OpenSSL::safe::opt_config_item -}
165 =head2 Operation options
171 Encrypt data for the given recipient certificates. Input file is the message
172 to be encrypted. The output file is the encrypted data in MIME format. The
173 actual CMS type is B<EnvelopedData>.
175 Note that no revocation check is done for the recipient cert, so if that
176 key has been compromised, others may be able to decrypt the text.
180 Decrypt data using the supplied certificate and private key. Expects
181 encrypted datain MIME format for the input file. The decrypted data
182 is written to the output file.
186 Sign data using the supplied certificate and private key. Input file is
187 the message to be signed. The signed data in MIME format is written
192 Verify signed data. Expects a signed data on input and outputs
193 the signed data. Both clear text and opaque signing is supported.
197 Resign a message: take an existing message and one or more new signers.
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> I<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<-digest> I<digest>
213 When used with B<-sign>, provides the digest in hexadecimal form instead of
214 computing it from the original message content. Cannot be combined with B<-in>
217 This operation is the CMS equivalent of L<openssl-pkeyutl(1)> signing.
218 When signing a pre-computed digest, the security relies on the digest and its
219 computation from the original message being trusted.
221 =item B<-digest_create>
223 Create a CMS B<DigestedData> type.
225 =item B<-digest_verify>
227 Verify a CMS B<DigestedData> type and output the content.
231 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
232 support for this option to work, otherwise it will output an error.
236 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
237 compiled with B<zlib> support for this option to work, otherwise it will
240 =item B<-EncryptedData_encrypt>
242 Encrypt content using supplied symmetric key and algorithm using a CMS
243 B<EncryptedData> type and output the content.
245 =item B<-EncryptedData_decrypt>
247 Decrypt content using supplied symmetric key and algorithm using a CMS
248 B<EncryptedData> type and output the content.
250 =item B<-data_create>
252 Create a CMS B<Data> type.
256 B<Data> type and output the content.
260 Takes an input message and writes out a PEM encoded CMS structure.
264 =head2 File format options
268 =item B<-inform> B<DER>|B<PEM>|B<SMIME>
270 The input format of the CMS structure (if one is being read);
271 the default is B<SMIME>.
272 See L<openssl-format-options(1)> for details.
274 =item B<-outform> B<DER>|B<PEM>|B<SMIME>
276 The output format of the CMS structure (if one is being written);
277 the default is B<SMIME>.
278 See L<openssl-format-options(1)> for details.
280 =item B<-rctform> B<DER>|B<PEM>|B<SMIME>
282 The signed receipt format for use with the B<-receipt_verify>; the default
284 See L<openssl-format-options(1)> for details.
286 =item B<-stream>, B<-indef>
288 The B<-stream> and B<-indef> options are equivalent and enable streaming I/O
289 for encoding operations. This permits single pass processing of data without
290 the need to hold the entire contents in memory, potentially supporting very
291 large files. Streaming is automatically set for S/MIME signing with detached
292 data if the output format is B<SMIME> it is currently off by default for all
297 Disable streaming I/O where it would produce and indefinite length constructed
298 encoding. This option currently has no effect. In future streaming will be
299 enabled by default on all relevant operations and this option will disable it.
303 Normally the input message is converted to "canonical" format which is
304 effectively using CR and LF as end of line: as required by the S/MIME
305 specification. When this option is present no translation occurs. This
306 is useful when handling binary data which may not be in MIME format.
310 Normally the output file uses a single B<LF> as end of line. When this
311 option is present B<CRLF> is used instead.
315 When signing use ASCII CRLF format canonicalisation. This strips trailing
316 whitespace from all lines, deletes trailing blank lines at EOF and sets
317 the encapsulated content type. This option is normally used with detached
318 content and an output signature format of DER. This option is not normally
319 needed when verifying as it is enabled automatically if the encapsulated
320 content format is detected.
324 =head2 Keys and password options
328 =item B<-pwri_password> I<password>
330 Specify password for recipient.
332 =item B<-secretkey> I<key>
334 Specify symmetric key to use. The key must be supplied in hex format and be
335 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
336 B<-EncryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
337 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
338 content encryption key using an AES key in the B<KEKRecipientInfo> type.
340 =item B<-secretkeyid> I<id>
342 The key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
343 This option B<must> be present if the B<-secretkey> option is used with
344 B<-encrypt>. With B<-decrypt> operations the I<id> is used to locate the
345 relevant key if it is not supplied then an attempt is used to decrypt any
346 B<KEKRecipientInfo> structures.
348 =item B<-inkey> I<filename>|I<uri>
350 The private key to use when signing or decrypting. This must match the
351 corresponding certificate. If this option is not specified then the
352 private key must be included in the certificate file specified with
353 the B<-recip> or B<-signer> file. When signing this option can be used
354 multiple times to specify successive keys.
356 =item B<-passin> I<arg>
358 The private key password source. For more information about the format of B<arg>
359 see L<openssl-passphrase-options(1)>.
361 =item B<-keyopt> I<name>:I<parameter>
363 For signing and encryption this option can be used multiple times to
364 set customised parameters for the preceding key or certificate. It can
365 currently be used to set RSA-PSS for signing, RSA-OAEP for encryption
366 or to modify default parameters for ECDH.
368 =item B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>
370 The format of the private key file; unspecified by default.
371 See L<openssl-format-options(1)> for details.
373 {- $OpenSSL::safe::opt_engine_item -}
375 {- $OpenSSL::safe::opt_provider_item -}
377 {- $OpenSSL::safe::opt_r_item -}
381 =head2 Encryption and decryption options
385 =item B<-originator> I<file>
387 A certificate of the originator of the encrypted message. Necessary for
388 decryption when Key Agreement is in use for a shared key.
390 =item B<-recip> I<file>
392 When decrypting a message this specifies the certificate of the recipient.
393 The certificate must match one of the recipients of the message.
395 When encrypting a message this option may be used multiple times to specify
396 each recipient. This form B<must> be used if customised parameters are
397 required (for example to specify RSA-OAEP).
399 Only certificates carrying RSA, Diffie-Hellman or EC keys are supported by this
402 =item I<recipient-cert> ...
404 This is an alternative to using the B<-recip> option when encrypting a message.
405 One or more certificate filenames may be given.
409 The encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
410 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
411 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
412 example B<-aes-128-cbc>. See L<openssl-enc(1)> for a list of ciphers
413 supported by your version of OpenSSL.
415 Currently the AES variants with GCM mode are the only supported AEAD
418 If not specified triple DES is used. Only used with B<-encrypt> and
419 B<-EncryptedData_create> commands.
421 =item B<-wrap> I<cipher>
423 Cipher algorithm to use for key wrap when encrypting the message using Key
424 Agreement for key transport. The algorithm specified should be suitable for key
427 =item B<-aes128-wrap>, B<-aes192-wrap>, B<-aes256-wrap>, B<-des3-wrap>
429 Use AES128, AES192, AES256, or 3DES-EDE, respectively, to wrap key.
430 Depending on the OpenSSL build options used, B<-des3-wrap> may not be supported.
432 =item B<-debug_decrypt>
434 This option sets the B<CMS_DEBUG_DECRYPT> flag. This option should be used
435 with caution: see the notes section below.
439 =head2 Signing options
443 =item B<-md> I<digest>
445 Digest algorithm to use when signing or resigning. If not present then the
446 default digest algorithm for the signing key will be used (usually SHA1).
448 =item B<-signer> I<file>
450 A signing certificate. When signing or resigning a message, this option can be
451 used multiple times if more than one signer is required.
453 =item B<-certfile> I<file>
455 Allows additional certificates to be specified. When signing these will
456 be included with the message. When verifying these will be searched for
457 the signers certificates.
458 The input can be in PEM, DER, or PKCS#12 format.
462 When used with B<-sign>,
463 add an ESS signingCertificate or ESS signingCertificateV2 signed-attribute
464 to the SignerInfo, in order to make the signature comply with the requirements
465 for a CAdES Basic Electronic Signature (CAdES-BES).
469 When signing a message use opaque signing: this form is more resistant
470 to translation by mail relays but it cannot be read by mail agents that
471 do not support S/MIME. Without this option cleartext signing with
472 the MIME type multipart/signed is used.
476 When signing a message the signer's certificate is normally included
477 with this option it is excluded. This will reduce the size of the
478 signed message but the verifier must have a copy of the signers certificate
479 available locally (passed using the B<-certfile> option for example).
483 Normally when a message is signed a set of attributes are included which
484 include the signing time and supported symmetric algorithms. With this
485 option they are not included.
489 Exclude the list of supported algorithms from signed attributes, other options
490 such as signing time and content type are still included.
492 =item B<-receipt_request_all>, B<-receipt_request_first>
494 For B<-sign> option include a signed receipt request. Indicate requests should
495 be provided by all recipient or first tier recipients (those mailed directly
496 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
498 =item B<-receipt_request_from> I<emailaddress>
500 For B<-sign> option include a signed receipt request. Add an explicit email
501 address where receipts should be supplied.
503 =item B<-receipt_request_to> I<emailaddress>
505 Add an explicit email address where signed receipts should be sent to. This
506 option B<must> but supplied if a signed receipt is requested.
510 =head2 Verification options
514 =item B<-signer> I<file>
516 If a message has been verified successfully then the signers certificate(s)
517 will be written to this file if the verification was successful.
519 =item B<-content> I<filename>
521 This specifies a file containing the detached content for operations taking
522 S/MIME input, such as the B<-verify> command. This is only usable if the CMS
523 structure is using the detached signature form where the content is
524 not included. This option will override any content if the input format
525 is S/MIME and it uses the multipart/signed MIME content type.
527 =item B<-no_content_verify>
529 Do not verify signed content signatures.
531 =item B<-no_attr_verify>
533 Do not verify signed attribute signatures.
537 Don't verify message signature.
541 Do not verify the signers certificate of a signed message.
545 When verifying a message normally certificates (if any) included in
546 the message are searched for the signing certificate. With this option
547 only the certificates specified in the B<-certfile> option are used.
548 The supplied certificates can still be used as untrusted CAs however.
552 When used with B<-verify>, require and check signer certificate digest.
553 See the NOTES section for more details.
555 =item B<-verify_retcode>
557 Exit nonzero on verification failure.
559 {- $OpenSSL::safe::opt_trust_item -}
563 =head2 Output options
569 Use subject key identifier to identify certificates instead of issuer name and
570 serial number. The supplied certificate B<must> include a subject key
571 identifier extension. Supported by B<-sign> and B<-encrypt> options.
573 =item B<-econtent_type> I<type>
575 Set the encapsulated content type to I<type> if not supplied the B<Data> type
576 is used. The I<type> argument can be any valid OID name in either text or
581 This option adds plain text (text/plain) MIME headers to the supplied
582 message if encrypting or signing. If decrypting or verifying it strips
583 off text headers: if the decrypted or verified message is not of MIME
584 type text/plain then an error occurs.
586 =item B<-certsout> I<file>
588 Any certificates contained in the input message are written to I<file>.
590 =item B<-to>, B<-from>, B<-subject>
592 The relevant email headers. These are included outside the signed
593 portion of a message so they may be included manually. If signing
594 then many S/MIME mail clients check the signers certificate's email
595 address matches that specified in the From: address.
599 =head2 Printing options
605 For the B<-cmsout> operation do not output the parsed CMS structure.
606 This is useful if the syntax of the CMS structure is being checked.
610 For the B<-cmsout> operation print out all fields of the CMS structure.
611 This implies B<-noout>.
612 This is mainly useful for testing purposes.
614 =item B<-nameopt> I<option>
616 For the B<-cmsout> operation when B<-print> option is in use, specifies
617 printing options for string fields. For most cases B<utf8> is reasonable value.
618 See L<openssl-namedisplay-options(1)> for details.
620 =item B<-receipt_request_print>
622 For the B<-verify> operation print out the contents of any signed receipt
627 =head2 Validation options
631 {- $OpenSSL::safe::opt_v_item -}
633 Any validation errors cause the command to exit.
639 The MIME message must be sent without any blank lines between the
640 headers and the output. Some mail programs will automatically add
641 a blank line. Piping the mail directly to sendmail is one way to
642 achieve the correct format.
644 The supplied message to be signed or encrypted must include the
645 necessary MIME headers or many S/MIME clients won't display it
646 properly (if at all). You can use the B<-text> option to automatically
647 add plain text headers.
649 A "signed and encrypted" message is one where a signed message is
650 then encrypted. This can be produced by encrypting an already signed
651 message: see the examples section.
653 This version of the program only allows one signer per message but it
654 will verify multiple signers on received messages. Some S/MIME clients
655 choke if a message contains multiple signers. It is possible to sign
656 messages "in parallel" by signing an already signed message.
658 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
659 clients. Strictly speaking these process CMS enveloped data: CMS
660 encrypted data is used for other purposes.
662 The B<-resign> option uses an existing message digest when adding a new
663 signer. This means that attributes must be present in at least one existing
664 signer using the same message digest or this operation will fail.
666 The B<-stream> and B<-indef> options enable streaming I/O support.
667 As a result the encoding is BER using indefinite length constructed encoding
668 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
669 B<-sign> operation if the content is not detached.
671 Streaming is always used for the B<-sign> operation with detached data but
672 since the content is no longer part of the CMS structure the encoding
675 If the B<-decrypt> option is used without a recipient certificate then an
676 attempt is made to locate the recipient by trying each potential recipient
677 in turn using the supplied private key. To thwart the MMA attack
678 (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all recipients are
679 tried whether they succeed or not and if no recipients match the message
680 is "decrypted" using a random key which will typically output garbage.
681 The B<-debug_decrypt> option can be used to disable the MMA attack protection
682 and return an error if no recipient can be found: this option should be used
683 with caution. For a fuller description see L<CMS_decrypt(3)>).
685 =head1 CADES BASIC ELECTRONIC SIGNATURE (CADES-BES)
687 A CAdES Basic Electronic Signature (CAdES-BES),
688 as defined in the European Standard ETSI EN 319 122-1 V1.1.1, contains:
694 The signed user data as defined in CMS (RFC 3852);
698 Content-type of the EncapsulatedContentInfo value being signed;
702 Message-digest of the eContent OCTET STRING within encapContentInfo being signed;
706 An ESS signingCertificate or ESS signingCertificateV2 attribute,
707 as defined in Enhanced Security Services (ESS), RFC 2634 and RFC 5035.
708 An ESS signingCertificate attribute only allows for SHA-1 as digest algorithm.
709 An ESS signingCertificateV2 attribute allows for any digest algorithm.
713 The digital signature value computed on the user data and, when present, on the signed attributes.
715 NOTE that the B<-cades> option applies to the B<-sign> or B<-verify> operations.
716 With this option, the B<-verify> operation also requires that the
717 signingCertificate attribute is present and checks that the given identifiers
718 match the verification trust chain built during the verification process.
728 The operation was completely successfully.
732 An error occurred parsing the command options.
736 One of the input files could not be read.
740 An error occurred creating the CMS file or when reading the MIME
745 An error occurred decrypting or verifying the message.
749 The message was verified correctly but an error occurred writing out
750 the signers certificates.
754 =head1 COMPATIBILITY WITH PKCS#7 FORMAT
756 L<openssl-smime(1)> can only process the older B<PKCS#7> format.
757 B<openssl cms> supports Cryptographic Message Syntax format.
758 Use of some features will result in messages which cannot be processed by
759 applications which only support the older format. These are detailed below.
761 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
763 The B<-outform> I<PEM> option uses different headers.
765 The B<-compress> option.
767 The B<-secretkey> option when used with B<-encrypt>.
769 The use of PSS with B<-sign>.
771 The use of OAEP or non-RSA keys with B<-encrypt>.
773 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
774 be processed by the older L<openssl-smime(1)> command.
778 Create a cleartext signed message:
780 openssl cms -sign -in message.txt -text -out mail.msg \
783 Create an opaque signed message
785 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
788 Create a signed message, include some additional certificates and
789 read the private key from another file:
791 openssl cms -sign -in in.txt -text -out mail.msg \
792 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
794 Create a signed message with two signers, use key identifier:
796 openssl cms -sign -in message.txt -text -out mail.msg \
797 -signer mycert.pem -signer othercert.pem -keyid
799 Send a signed message under Unix directly to sendmail, including headers:
801 openssl cms -sign -in in.txt -text -signer mycert.pem \
802 -from steve@openssl.org -to someone@somewhere \
803 -subject "Signed message" | sendmail someone@somewhere
805 Verify a message and extract the signer's certificate if successful:
807 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
809 Send encrypted mail using triple DES:
811 openssl cms -encrypt -in in.txt -from steve@openssl.org \
812 -to someone@somewhere -subject "Encrypted message" \
813 -des3 user.pem -out mail.msg
815 Sign and encrypt mail:
817 openssl cms -sign -in ml.txt -signer my.pem -text \
818 | openssl cms -encrypt -out mail.msg \
819 -from steve@openssl.org -to someone@somewhere \
820 -subject "Signed and Encrypted message" -des3 user.pem
822 Note: the encryption command does not include the B<-text> option because the
823 message being encrypted already has MIME headers.
827 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
829 The output from Netscape form signing is a PKCS#7 structure with the
830 detached signature format. You can use this program to verify the
831 signature by line wrapping the base64 encoded structure and surrounding
834 -----BEGIN PKCS7-----
837 and using the command,
839 openssl cms -verify -inform PEM -in signature.pem -content content.txt
841 alternatively you can base64 decode the signature and use
843 openssl cms -verify -inform DER -in signature.der -content content.txt
845 Create an encrypted message using 128 bit Camellia:
847 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
849 Add a signer to an existing message:
851 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
853 Sign a message using RSA-PSS:
855 openssl cms -sign -in message.txt -text -out mail.msg \
856 -signer mycert.pem -keyopt rsa_padding_mode:pss
858 Create an encrypted message using RSA-OAEP:
860 openssl cms -encrypt -in plain.txt -out mail.msg \
861 -recip cert.pem -keyopt rsa_padding_mode:oaep
863 Use SHA256 KDF with an ECDH certificate:
865 openssl cms -encrypt -in plain.txt -out mail.msg \
866 -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
868 Print CMS signed binary data in human-readable form:
870 openssl cms -in signed.cms -binary -inform DER -cmsout -print
874 The MIME parser isn't very clever: it seems to handle most messages that I've
875 thrown at it but it may choke on others.
877 The code currently will only write out the signer's certificate to a file: if
878 the signer has a separate encryption certificate this must be manually
879 extracted. There should be some heuristic that determines the correct
880 encryption certificate.
882 Ideally a database should be maintained of a certificates for each email
885 The code doesn't currently take note of the permitted symmetric encryption
886 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
887 user has to manually include the correct encryption algorithm. It should store
888 the list of permitted ciphers in a database and only use those.
890 No revocation checking is done on the signer's certificate.
894 L<ossl_store-file(7)>
898 The use of multiple B<-signer> options and the B<-resign> command were first
899 added in OpenSSL 1.0.0.
901 The B<-keyopt> option was added in OpenSSL 1.0.2.
903 Support for RSA-OAEP and RSA-PSS was added in OpenSSL 1.0.2.
905 The use of non-RSA keys with B<-encrypt> and B<-decrypt>
906 was added in OpenSSL 1.0.2.
908 The -no_alt_chains option was added in OpenSSL 1.0.2b.
910 The B<-nameopt> option was added in OpenSSL 3.0.0.
912 The B<-engine> option was deprecated in OpenSSL 3.0.
914 The B<-digest> option was added in OpenSSL 3.2.
918 Copyright 2008-2022 The OpenSSL Project Authors. All Rights Reserved.
920 Licensed under the Apache License 2.0 (the "License"). You may not use
921 this file except in compliance with the License. You can obtain a copy
922 in the file LICENSE in the source distribution or at
923 L<https://www.openssl.org/source/license.html>.