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 -receipt_request_first>]
87 [B<-receipt_request_from emailaddress>]
88 [B<-receipt_request_to emailaddress>]
89 [B<-receipt_request_print>]
92 [B<-econtent_type type>]
94 [B<-keyopt name:parameter>]
106 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
107 verify, compress and uncompress S/MIME messages.
111 There are fourteen operation options that set the type of operation to be
112 performed. The meaning of the other options varies according to the operation
119 Print out a usage message.
123 Encrypt mail for the given recipient certificates. Input file is the message
124 to be encrypted. The output file is the encrypted mail in MIME format. The
125 actual CMS type is <B>EnvelopedData<B>.
127 Note that no revocation check is done for the recipient cert, so if that
128 key has been compromised, others may be able to decrypt the text.
132 Decrypt mail using the supplied certificate and private key. Expects an
133 encrypted mail message in MIME format for the input file. The decrypted mail
134 is written to the output file.
136 =item B<-debug_decrypt>
138 This option sets the B<CMS_DEBUG_DECRYPT> flag. This option should be used
139 with caution: see the notes section below.
143 Sign mail using the supplied certificate and private key. Input file is
144 the message to be signed. The signed message in MIME format is written
149 Verify signed mail. Expects a signed mail message on input and outputs
150 the signed data. Both clear text and opaque signing is supported.
154 Takes an input message and writes out a PEM encoded CMS structure.
158 Resign a message: take an existing message and one or more new signers.
160 =item B<-data_create>
162 Create a CMS B<Data> type.
166 B<Data> type and output the content.
168 =item B<-digest_create>
170 Create a CMS B<DigestedData> type.
172 =item B<-digest_verify>
174 Verify a CMS B<DigestedData> type and output the content.
178 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
179 support for this option to work, otherwise it will output an error.
183 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
184 compiled with B<zlib> support for this option to work, otherwise it will
187 =item B<-EncryptedData_encrypt>
189 Encrypt content using supplied symmetric key and algorithm using a CMS
190 B<EncryptedData> type and output the content.
192 =item B<-sign_receipt>
194 Generate and output a signed receipt for the supplied message. The input
195 message B<must> contain a signed receipt request. Functionality is otherwise
196 similar to the B<-sign> operation.
198 =item B<-verify_receipt receipt>
200 Verify a signed receipt in filename B<receipt>. The input message B<must>
201 contain the original receipt request. Functionality is otherwise similar
202 to the B<-verify> operation.
204 =item B<-in filename>
206 The input message to be encrypted or signed or the message to be decrypted
209 =item B<-inform SMIME|PEM|DER>
211 This specifies the input format for the CMS structure. The default
212 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
213 format change this to expect PEM and DER format CMS structures
214 instead. This currently only affects the input format of the CMS
215 structure, if no CMS structure is being input (for example with
216 B<-encrypt> or B<-sign>) this option has no effect.
218 =item B<-rctform SMIME|PEM|DER>
220 Specify the format for a signed receipt for use with the B<-receipt_verify>
223 =item B<-out filename>
225 The message text that has been decrypted or verified or the output MIME
226 format message that has been signed or verified.
228 =item B<-outform SMIME|PEM|DER>
230 This specifies the output format for the CMS structure. The default
231 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
232 format change this to write PEM and DER format CMS structures
233 instead. This currently only affects the output format of the CMS
234 structure, if no CMS structure is being output (for example with
235 B<-verify> or B<-decrypt>) this option has no effect.
237 =item B<-stream -indef -noindef>
239 The B<-stream> and B<-indef> options are equivalent and enable streaming I/O
240 for encoding operations. This permits single pass processing of data without
241 the need to hold the entire contents in memory, potentially supporting very
242 large files. Streaming is automatically set for S/MIME signing with detached
243 data if the output format is B<SMIME> it is currently off by default for all
248 Disable streaming I/O where it would produce and indefinite length constructed
249 encoding. This option currently has no effect. In future streaming will be
250 enabled by default on all relevant operations and this option will disable it.
252 =item B<-content filename>
254 This specifies a file containing the detached content, this is only
255 useful with the B<-verify> command. This is only usable if the CMS
256 structure is using the detached signature form where the content is
257 not included. This option will override any content if the input format
258 is S/MIME and it uses the multipart/signed MIME content type.
262 This option adds plain text (text/plain) MIME headers to the supplied
263 message if encrypting or signing. If decrypting or verifying it strips
264 off text headers: if the decrypted or verified message is not of MIME
265 type text/plain then an error occurs.
269 For the B<-cmsout> operation do not output the parsed CMS structure. This
270 is useful when combined with the B<-print> option or if the syntax of the CMS
271 structure is being checked.
275 For the B<-cmsout> operation print out all fields of the CMS structure. This
276 is mainly useful for testing purposes.
278 =item B<-CAfile file>
280 A file containing trusted CA certificates, only used with B<-verify>.
284 A directory containing trusted CA certificates, only used with
285 B<-verify>. This directory must be a standard certificate directory: that
286 is a hash of each subject name (using B<x509 -hash>) should be linked
291 Do not load the trusted CA certificates from the default file location
295 Do not load the trusted CA certificates from the default directory location
299 Digest algorithm to use when signing or resigning. If not present then the
300 default digest algorithm for the signing key will be used (usually SHA1).
304 The encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
305 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
306 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
307 example B<-aes-128-cbc>. See L<B<enc>|enc(1)> for a list of ciphers
308 supported by your version of OpenSSL.
310 If not specified triple DES is used. Only used with B<-encrypt> and
311 B<-EncryptedData_create> commands.
315 When verifying a message normally certificates (if any) included in
316 the message are searched for the signing certificate. With this option
317 only the certificates specified in the B<-certfile> option are used.
318 The supplied certificates can still be used as untrusted CAs however.
322 Do not verify the signers certificate of a signed message.
326 When signing a message the signer's certificate is normally included
327 with this option it is excluded. This will reduce the size of the
328 signed message but the verifier must have a copy of the signers certificate
329 available locally (passed using the B<-certfile> option for example).
333 Normally when a message is signed a set of attributes are included which
334 include the signing time and supported symmetric algorithms. With this
335 option they are not included.
339 Exclude the list of supported algorithms from signed attributes, other options
340 such as signing time and content type are still included.
344 Normally the input message is converted to "canonical" format which is
345 effectively using CR and LF as end of line: as required by the S/MIME
346 specification. When this option is present no translation occurs. This
347 is useful when handling binary data which may not be in MIME format.
351 Normally the output file uses a single B<LF> as end of line. When this
352 option is present B<CRLF> is used instead.
356 When signing use ASCII CRLF format canonicalisation. This strips trailing
357 whitespace from all lines, deletes trailing blank lines at EOF and sets
358 the encapsulated content type. This option is normally used with detached
359 content and an output signature format of DER. This option is not normally
360 needed when verifying as it is enabled automatically if the encapsulated
361 content format is detected.
365 When signing a message use opaque signing: this form is more resistant
366 to translation by mail relays but it cannot be read by mail agents that
367 do not support S/MIME. Without this option cleartext signing with
368 the MIME type multipart/signed is used.
370 =item B<-certfile file>
372 Allows additional certificates to be specified. When signing these will
373 be included with the message. When verifying these will be searched for
374 the signers certificates. The certificates should be in PEM format.
376 =item B<-certsout file>
378 Any certificates contained in the message are written to B<file>.
380 =item B<-signer file>
382 A signing certificate when signing or resigning a message, this option can be
383 used multiple times if more than one signer is required. If a message is being
384 verified then the signers certificates will be written to this file if the
385 verification was successful.
389 When decrypting a message this specifies the recipients certificate. The
390 certificate must match one of the recipients of the message or an error
393 When encrypting a message this option may be used multiple times to specify
394 each recipient. This form B<must> be used if customised parameters are
395 required (for example to specify RSA-OAEP).
397 Only certificates carrying RSA, Diffie-Hellman or EC keys are supported by this
402 Use subject key identifier to identify certificates instead of issuer name and
403 serial number. The supplied certificate B<must> include a subject key
404 identifier extension. Supported by B<-sign> and B<-encrypt> options.
406 =item B<-receipt_request_all -receipt_request_first>
408 For B<-sign> option include a signed receipt request. Indicate requests should
409 be provided by all recipient or first tier recipients (those mailed directly
410 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
412 =item B<-receipt_request_from emailaddress>
414 For B<-sign> option include a signed receipt request. Add an explicit email
415 address where receipts should be supplied.
417 =item B<-receipt_request_to emailaddress>
419 Add an explicit email address where signed receipts should be sent to. This
420 option B<must> but supplied if a signed receipt it requested.
422 =item B<-receipt_request_print>
424 For the B<-verify> operation print out the contents of any signed receipt
427 =item B<-secretkey key>
429 Specify symmetric key to use. The key must be supplied in hex format and be
430 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
431 B<-EncryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
432 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
433 content encryption key using an AES key in the B<KEKRecipientInfo> type.
435 =item B<-secretkeyid id>
437 The key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
438 This option B<must> be present if the B<-secretkey> option is used with
439 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
440 relevant key if it is not supplied then an attempt is used to decrypt any
441 B<KEKRecipientInfo> structures.
443 =item B<-econtent_type type>
445 Set the encapsulated content type to B<type> if not supplied the B<Data> type
446 is used. The B<type> argument can be any valid OID name in either text or
451 The private key to use when signing or decrypting. This must match the
452 corresponding certificate. If this option is not specified then the
453 private key must be included in the certificate file specified with
454 the B<-recip> or B<-signer> file. When signing this option can be used
455 multiple times to specify successive keys.
457 =item B<-keyopt name:opt>
459 For signing and encryption this option can be used multiple times to
460 set customised parameters for the preceding key or certificate. It can
461 currently be used to set RSA-PSS for signing, RSA-OAEP for encryption
462 or to modify default parameters for ECDH.
466 The private key password source. For more information about the format of B<arg>
467 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
469 =item B<-rand file...>
471 A file or files containing random data used to seed the random number
473 Multiple files can be specified separated by an OS-dependent character.
474 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
477 =item [B<-writerand file>]
479 Writes random data to the specified I<file> upon exit.
480 This can be used with a subsequent B<-rand> flag.
484 One or more certificates of message recipients: used when encrypting
487 =item B<-to, -from, -subject>
489 The relevant mail headers. These are included outside the signed
490 portion of a message so they may be included manually. If signing
491 then many S/MIME mail clients check the signers certificate's email
492 address matches that specified in the From: address.
494 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
495 B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
496 B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
497 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
498 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
499 B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
500 B<-verify_ip>, B<-verify_name>, B<-x509_strict>
502 Set various certificate chain validation options. See the
503 L<verify(1)> manual page for details.
509 The MIME message must be sent without any blank lines between the
510 headers and the output. Some mail programs will automatically add
511 a blank line. Piping the mail directly to sendmail is one way to
512 achieve the correct format.
514 The supplied message to be signed or encrypted must include the
515 necessary MIME headers or many S/MIME clients won't display it
516 properly (if at all). You can use the B<-text> option to automatically
517 add plain text headers.
519 A "signed and encrypted" message is one where a signed message is
520 then encrypted. This can be produced by encrypting an already signed
521 message: see the examples section.
523 This version of the program only allows one signer per message but it
524 will verify multiple signers on received messages. Some S/MIME clients
525 choke if a message contains multiple signers. It is possible to sign
526 messages "in parallel" by signing an already signed message.
528 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
529 clients. Strictly speaking these process CMS enveloped data: CMS
530 encrypted data is used for other purposes.
532 The B<-resign> option uses an existing message digest when adding a new
533 signer. This means that attributes must be present in at least one existing
534 signer using the same message digest or this operation will fail.
536 The B<-stream> and B<-indef> options enable streaming I/O support.
537 As a result the encoding is BER using indefinite length constructed encoding
538 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
539 B<-sign> operation if the content is not detached.
541 Streaming is always used for the B<-sign> operation with detached data but
542 since the content is no longer part of the CMS structure the encoding
545 If the B<-decrypt> option is used without a recipient certificate then an
546 attempt is made to locate the recipient by trying each potential recipient
547 in turn using the supplied private key. To thwart the MMA attack
548 (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all recipients are
549 tried whether they succeed or not and if no recipients match the message
550 is "decrypted" using a random key which will typically output garbage.
551 The B<-debug_decrypt> option can be used to disable the MMA attack protection
552 and return an error if no recipient can be found: this option should be used
553 with caution. For a fuller description see L<CMS_decrypt(3)>).
561 The operation was completely successfully.
565 An error occurred parsing the command options.
569 One of the input files could not be read.
573 An error occurred creating the CMS file or when reading the MIME
578 An error occurred decrypting or verifying the message.
582 The message was verified correctly but an error occurred writing out
583 the signers certificates.
587 =head1 COMPATIBILITY WITH PKCS#7 format.
589 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
590 utility supports Cryptographic Message Syntax format. Use of some features
591 will result in messages which cannot be processed by applications which only
592 support the older format. These are detailed below.
594 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
596 The B<-outform PEM> option uses different headers.
598 The B<-compress> option.
600 The B<-secretkey> option when used with B<-encrypt>.
602 The use of PSS with B<-sign>.
604 The use of OAEP or non-RSA keys with B<-encrypt>.
606 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
607 be processed by the older B<smime> command.
611 Create a cleartext signed message:
613 openssl cms -sign -in message.txt -text -out mail.msg \
616 Create an opaque signed message
618 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
621 Create a signed message, include some additional certificates and
622 read the private key from another file:
624 openssl cms -sign -in in.txt -text -out mail.msg \
625 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
627 Create a signed message with two signers, use key identifier:
629 openssl cms -sign -in message.txt -text -out mail.msg \
630 -signer mycert.pem -signer othercert.pem -keyid
632 Send a signed message under Unix directly to sendmail, including headers:
634 openssl cms -sign -in in.txt -text -signer mycert.pem \
635 -from steve@openssl.org -to someone@somewhere \
636 -subject "Signed message" | sendmail someone@somewhere
638 Verify a message and extract the signer's certificate if successful:
640 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
642 Send encrypted mail using triple DES:
644 openssl cms -encrypt -in in.txt -from steve@openssl.org \
645 -to someone@somewhere -subject "Encrypted message" \
646 -des3 user.pem -out mail.msg
648 Sign and encrypt mail:
650 openssl cms -sign -in ml.txt -signer my.pem -text \
651 | openssl cms -encrypt -out mail.msg \
652 -from steve@openssl.org -to someone@somewhere \
653 -subject "Signed and Encrypted message" -des3 user.pem
655 Note: the encryption command does not include the B<-text> option because the
656 message being encrypted already has MIME headers.
660 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
662 The output from Netscape form signing is a PKCS#7 structure with the
663 detached signature format. You can use this program to verify the
664 signature by line wrapping the base64 encoded structure and surrounding
667 -----BEGIN PKCS7-----
670 and using the command,
672 openssl cms -verify -inform PEM -in signature.pem -content content.txt
674 alternatively you can base64 decode the signature and use
676 openssl cms -verify -inform DER -in signature.der -content content.txt
678 Create an encrypted message using 128 bit Camellia:
680 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
682 Add a signer to an existing message:
684 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
686 Sign mail using RSA-PSS:
688 openssl cms -sign -in message.txt -text -out mail.msg \
689 -signer mycert.pem -keyopt rsa_padding_mode:pss
691 Create encrypted mail using RSA-OAEP:
693 openssl cms -encrypt -in plain.txt -out mail.msg \
694 -recip cert.pem -keyopt rsa_padding_mode:oaep
696 Use SHA256 KDF with an ECDH certificate:
698 openssl cms -encrypt -in plain.txt -out mail.msg \
699 -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
703 The MIME parser isn't very clever: it seems to handle most messages that I've
704 thrown at it but it may choke on others.
706 The code currently will only write out the signer's certificate to a file: if
707 the signer has a separate encryption certificate this must be manually
708 extracted. There should be some heuristic that determines the correct
709 encryption certificate.
711 Ideally a database should be maintained of a certificates for each email
714 The code doesn't currently take note of the permitted symmetric encryption
715 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
716 user has to manually include the correct encryption algorithm. It should store
717 the list of permitted ciphers in a database and only use those.
719 No revocation checking is done on the signer's certificate.
723 The use of multiple B<-signer> options and the B<-resign> command were first
724 added in OpenSSL 1.0.0.
726 The B<keyopt> option was first added in OpenSSL 1.0.2.
728 Support for RSA-OAEP and RSA-PSS was first added to OpenSSL 1.0.2.
730 The use of non-RSA keys with B<-encrypt> and B<-decrypt> was first added
733 The -no_alt_chains options was first added to OpenSSL 1.0.2b.
737 Copyright 2008-2017 The OpenSSL Project Authors. All Rights Reserved.
739 Licensed under the OpenSSL license (the "License"). You may not use
740 this file except in compliance with the License. You can obtain a copy
741 in the file LICENSE in the source distribution or at
742 L<https://www.openssl.org/source/license.html>.