23 [B<-EncryptedData_encrypt>]
25 [B<-verify_receipt receipt>]
27 [B<-inform SMIME|PEM|DER>]
28 [B<-rctform SMIME|PEM|DER>]
30 [B<-outform SMIME|PEM|DER>]
31 [B<-stream -indef -noindef>]
33 [B<-content filename>]
41 [B<-attime timestamp>]
63 [B<-verify_depth num>]
64 [B<-verify_email email>]
65 [B<-verify_hostname hostname>]
67 [B<-verify_name name>]
72 [B<-no_signer_cert_verify>]
85 [B<-receipt_request_all -receipt_request_first>]
86 [B<-receipt_request_from emailaddress>]
87 [B<-receipt_request_to emailaddress>]
88 [B<-receipt_request_print>]
91 [B<-econtent_type type>]
93 [B<-keyopt name:parameter>]
104 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
105 verify, compress and uncompress S/MIME messages.
109 There are fourteen operation options that set the type of operation to be
110 performed. The meaning of the other options varies according to the operation
117 Print out a usage message.
121 encrypt mail for the given recipient certificates. Input file is the message
122 to be encrypted. The output file is the encrypted mail in MIME format. The
123 actual CMS type is <B>EnvelopedData<B>.
125 Note that no revocation check is done for the recipient cert, so if that
126 key has been compromised, others may be able to decrypt the text.
130 decrypt mail using the supplied certificate and private key. Expects an
131 encrypted mail message in MIME format for the input file. The decrypted mail
132 is written to the output file.
134 =item B<-debug_decrypt>
136 this option sets the B<CMS_DEBUG_DECRYPT> flag. This option should be used
137 with caution: see the notes section below.
141 sign mail using the supplied certificate and private key. Input file is
142 the message to be signed. The signed message in MIME format is written
147 verify signed mail. Expects a signed mail message on input and outputs
148 the signed data. Both clear text and opaque signing is supported.
152 takes an input message and writes out a PEM encoded CMS structure.
156 resign a message: take an existing message and one or more new signers.
158 =item B<-data_create>
160 Create a CMS B<Data> type.
164 B<Data> type and output the content.
166 =item B<-digest_create>
168 Create a CMS B<DigestedData> type.
170 =item B<-digest_verify>
172 Verify a CMS B<DigestedData> type and output the content.
176 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
177 support for this option to work, otherwise it will output an error.
181 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
182 compiled with B<zlib> support for this option to work, otherwise it will
185 =item B<-EncryptedData_encrypt>
187 Encrypt content using supplied symmetric key and algorithm using a CMS
188 B<EncrytedData> type and output the content.
190 =item B<-sign_receipt>
192 Generate and output a signed receipt for the supplied message. The input
193 message B<must> contain a signed receipt request. Functionality is otherwise
194 similar to the B<-sign> operation.
196 =item B<-verify_receipt receipt>
198 Verify a signed receipt in filename B<receipt>. The input message B<must>
199 contain the original receipt request. Functionality is otherwise similar
200 to the B<-verify> operation.
202 =item B<-in filename>
204 the input message to be encrypted or signed or the message to be decrypted
207 =item B<-inform SMIME|PEM|DER>
209 this specifies the input format for the CMS structure. The default
210 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
211 format change this to expect PEM and DER format CMS structures
212 instead. This currently only affects the input format of the CMS
213 structure, if no CMS structure is being input (for example with
214 B<-encrypt> or B<-sign>) this option has no effect.
216 =item B<-rctform SMIME|PEM|DER>
218 specify the format for a signed receipt for use with the B<-receipt_verify>
221 =item B<-out filename>
223 the message text that has been decrypted or verified or the output MIME
224 format message that has been signed or verified.
226 =item B<-outform SMIME|PEM|DER>
228 this specifies the output format for the CMS structure. The default
229 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
230 format change this to write PEM and DER format CMS structures
231 instead. This currently only affects the output format of the CMS
232 structure, if no CMS structure is being output (for example with
233 B<-verify> or B<-decrypt>) this option has no effect.
235 =item B<-stream -indef -noindef>
237 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
238 for encoding operations. This permits single pass processing of data without
239 the need to hold the entire contents in memory, potentially supporting very
240 large files. Streaming is automatically set for S/MIME signing with detached
241 data if the output format is B<SMIME> it is currently off by default for all
246 disable streaming I/O where it would produce and indefinite length constructed
247 encoding. This option currently has no effect. In future streaming will be
248 enabled by default on all relevant operations and this option will disable it.
250 =item B<-content filename>
252 This specifies a file containing the detached content, this is only
253 useful with the B<-verify> command. This is only usable if the CMS
254 structure is using the detached signature form where the content is
255 not included. This option will override any content if the input format
256 is S/MIME and it uses the multipart/signed MIME content type.
260 this option adds plain text (text/plain) MIME headers to the supplied
261 message if encrypting or signing. If decrypting or verifying it strips
262 off text headers: if the decrypted or verified message is not of MIME
263 type text/plain then an error occurs.
267 for the B<-cmsout> operation do not output the parsed CMS structure. This
268 is useful when combined with the B<-print> option or if the syntax of the CMS
269 structure is being checked.
273 for the B<-cmsout> operation print out all fields of the CMS structure. This
274 is mainly useful for testing purposes.
276 =item B<-CAfile file>
278 a file containing trusted CA certificates, only used with B<-verify>.
282 a directory containing trusted CA certificates, only used with
283 B<-verify>. This directory must be a standard certificate directory: that
284 is a hash of each subject name (using B<x509 -hash>) should be linked
289 Do not load the trusted CA certificates from the default file location
293 Do not load the trusted CA certificates from the default directory location
297 digest algorithm to use when signing or resigning. If not present then the
298 default digest algorithm for the signing key will be used (usually SHA1).
302 the encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
303 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
304 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
305 example B<-aes-128-cbc>. See L<B<enc>|enc(1)> for a list of ciphers
306 supported by your version of OpenSSL.
308 If not specified triple DES is used. Only used with B<-encrypt> and
309 B<-EncryptedData_create> commands.
313 when verifying a message normally certificates (if any) included in
314 the message are searched for the signing certificate. With this option
315 only the certificates specified in the B<-certfile> option are used.
316 The supplied certificates can still be used as untrusted CAs however.
318 =item B<-no_signer_cert_verify>
320 do not verify the signers certificate of a signed message.
324 when signing a message the signer's certificate is normally included
325 with this option it is excluded. This will reduce the size of the
326 signed message but the verifier must have a copy of the signers certificate
327 available locally (passed using the B<-certfile> option for example).
331 normally when a message is signed a set of attributes are included which
332 include the signing time and supported symmetric algorithms. With this
333 option they are not included.
337 exclude the list of supported algorithms from signed attributes, other options
338 such as signing time and content type are still included.
342 normally the input message is converted to "canonical" format which is
343 effectively using CR and LF as end of line: as required by the S/MIME
344 specification. When this option is present no translation occurs. This
345 is useful when handling binary data which may not be in MIME format.
349 normally the output file uses a single B<LF> as end of line. When this
350 option is present B<CRLF> is used instead.
354 when signing use ASCII CRLF format canonicalisation. This strips trailing
355 whitespace from all lines, deletes trailing blank lines at EOF and sets
356 the encapsulated content type. This option is normally used with detached
357 content and an output signature format of DER. This option is not normally
358 needed when verifying as it is enabled automatically if the encapsulated
359 content format is detected.
363 when signing a message use opaque signing: this form is more resistant
364 to translation by mail relays but it cannot be read by mail agents that
365 do not support S/MIME. Without this option cleartext signing with
366 the MIME type multipart/signed is used.
368 =item B<-certfile file>
370 allows additional certificates to be specified. When signing these will
371 be included with the message. When verifying these will be searched for
372 the signers certificates. The certificates should be in PEM format.
374 =item B<-certsout file>
376 any certificates contained in the message are written to B<file>.
378 =item B<-signer file>
380 a signing certificate when signing or resigning a message, this option can be
381 used multiple times if more than one signer is required. If a message is being
382 verified then the signers certificates will be written to this file if the
383 verification was successful.
387 when decrypting a message this specifies the recipients certificate. The
388 certificate must match one of the recipients of the message or an error
391 When encrypting a message this option may be used multiple times to specify
392 each recipient. This form B<must> be used if customised parameters are
393 required (for example to specify RSA-OAEP).
397 use subject key identifier to identify certificates instead of issuer name and
398 serial number. The supplied certificate B<must> include a subject key
399 identifier extension. Supported by B<-sign> and B<-encrypt> options.
401 =item B<-receipt_request_all -receipt_request_first>
403 for B<-sign> option include a signed receipt request. Indicate requests should
404 be provided by all recipient or first tier recipients (those mailed directly
405 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
407 =item B<-receipt_request_from emailaddress>
409 for B<-sign> option include a signed receipt request. Add an explicit email
410 address where receipts should be supplied.
412 =item B<-receipt_request_to emailaddress>
414 Add an explicit email address where signed receipts should be sent to. This
415 option B<must> but supplied if a signed receipt it requested.
417 =item B<-receipt_request_print>
419 For the B<-verify> operation print out the contents of any signed receipt
422 =item B<-secretkey key>
424 specify symmetric key to use. The key must be supplied in hex format and be
425 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
426 B<-EncryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
427 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
428 content encryption key using an AES key in the B<KEKRecipientInfo> type.
430 =item B<-secretkeyid id>
432 the key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
433 This option B<must> be present if the B<-secretkey> option is used with
434 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
435 relevant key if it is not supplied then an attempt is used to decrypt any
436 B<KEKRecipientInfo> structures.
438 =item B<-econtent_type type>
440 set the encapsulated content type to B<type> if not supplied the B<Data> type
441 is used. The B<type> argument can be any valid OID name in either text or
446 the private key to use when signing or decrypting. This must match the
447 corresponding certificate. If this option is not specified then the
448 private key must be included in the certificate file specified with
449 the B<-recip> or B<-signer> file. When signing this option can be used
450 multiple times to specify successive keys.
452 =item B<-keyopt name:opt>
454 for signing and encryption this option can be used multiple times to
455 set customised parameters for the preceding key or certificate. It can
456 currently be used to set RSA-PSS for signing, RSA-OAEP for encryption
457 or to modify default parameters for ECDH.
461 the private key password source. For more information about the format of B<arg>
462 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
464 =item B<-rand file(s)>
466 a file or files containing random data used to seed the random number
467 generator, or an EGD socket (see L<RAND_egd(3)>).
468 Multiple files can be specified separated by an OS-dependent character.
469 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
474 one or more certificates of message recipients: used when encrypting
477 =item B<-to, -from, -subject>
479 the relevant mail headers. These are included outside the signed
480 portion of a message so they may be included manually. If signing
481 then many S/MIME mail clients check the signers certificate's email
482 address matches that specified in the From: address.
484 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
485 B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
486 B<-inhibit_map>, B<-no_alt_chains>, B<-no_check_time>, B<-partial_chain>, B<-policy>,
487 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
488 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
489 B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
490 B<-verify_ip>, B<-verify_name>, B<-x509_strict>
492 Set various certificate chain validation options. See the
493 L<verify(1)> manual page for details.
499 The MIME message must be sent without any blank lines between the
500 headers and the output. Some mail programs will automatically add
501 a blank line. Piping the mail directly to sendmail is one way to
502 achieve the correct format.
504 The supplied message to be signed or encrypted must include the
505 necessary MIME headers or many S/MIME clients won't display it
506 properly (if at all). You can use the B<-text> option to automatically
507 add plain text headers.
509 A "signed and encrypted" message is one where a signed message is
510 then encrypted. This can be produced by encrypting an already signed
511 message: see the examples section.
513 This version of the program only allows one signer per message but it
514 will verify multiple signers on received messages. Some S/MIME clients
515 choke if a message contains multiple signers. It is possible to sign
516 messages "in parallel" by signing an already signed message.
518 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
519 clients. Strictly speaking these process CMS enveloped data: CMS
520 encrypted data is used for other purposes.
522 The B<-resign> option uses an existing message digest when adding a new
523 signer. This means that attributes must be present in at least one existing
524 signer using the same message digest or this operation will fail.
526 The B<-stream> and B<-indef> options enable streaming I/O support.
527 As a result the encoding is BER using indefinite length constructed encoding
528 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
529 B<-sign> operation if the content is not detached.
531 Streaming is always used for the B<-sign> operation with detached data but
532 since the content is no longer part of the CMS structure the encoding
535 If the B<-decrypt> option is used without a recipient certificate then an
536 attempt is made to locate the recipient by trying each potential recipient
537 in turn using the supplied private key. To thwart the MMA attack
538 (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all recipients are
539 tried whether they succeed or not and if no recipients match the message
540 is "decrypted" using a random key which will typically output garbage.
541 The B<-debug_decrypt> option can be used to disable the MMA attack protection
542 and return an error if no recipient can be found: this option should be used
543 with caution. For a fuller description see L<CMS_decrypt(3)>).
551 the operation was completely successfully.
555 an error occurred parsing the command options.
559 one of the input files could not be read.
563 an error occurred creating the CMS file or when reading the MIME
568 an error occurred decrypting or verifying the message.
572 the message was verified correctly but an error occurred writing out
573 the signers certificates.
577 =head1 COMPATIBILITY WITH PKCS#7 format.
579 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
580 utility supports Cryptographic Message Syntax format. Use of some features
581 will result in messages which cannot be processed by applications which only
582 support the older format. These are detailed below.
584 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
586 The B<-outform PEM> option uses different headers.
588 The B<-compress> option.
590 The B<-secretkey> option when used with B<-encrypt>.
592 The use of PSS with B<-sign>.
594 The use of OAEP or non-RSA keys with B<-encrypt>.
596 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
597 be processed by the older B<smime> command.
601 Create a cleartext signed message:
603 openssl cms -sign -in message.txt -text -out mail.msg \
606 Create an opaque signed message
608 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
611 Create a signed message, include some additional certificates and
612 read the private key from another file:
614 openssl cms -sign -in in.txt -text -out mail.msg \
615 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
617 Create a signed message with two signers, use key identifier:
619 openssl cms -sign -in message.txt -text -out mail.msg \
620 -signer mycert.pem -signer othercert.pem -keyid
622 Send a signed message under Unix directly to sendmail, including headers:
624 openssl cms -sign -in in.txt -text -signer mycert.pem \
625 -from steve@openssl.org -to someone@somewhere \
626 -subject "Signed message" | sendmail someone@somewhere
628 Verify a message and extract the signer's certificate if successful:
630 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
632 Send encrypted mail using triple DES:
634 openssl cms -encrypt -in in.txt -from steve@openssl.org \
635 -to someone@somewhere -subject "Encrypted message" \
636 -des3 user.pem -out mail.msg
638 Sign and encrypt mail:
640 openssl cms -sign -in ml.txt -signer my.pem -text \
641 | openssl cms -encrypt -out mail.msg \
642 -from steve@openssl.org -to someone@somewhere \
643 -subject "Signed and Encrypted message" -des3 user.pem
645 Note: the encryption command does not include the B<-text> option because the
646 message being encrypted already has MIME headers.
650 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
652 The output from Netscape form signing is a PKCS#7 structure with the
653 detached signature format. You can use this program to verify the
654 signature by line wrapping the base64 encoded structure and surrounding
657 -----BEGIN PKCS7-----
660 and using the command,
662 openssl cms -verify -inform PEM -in signature.pem -content content.txt
664 alternatively you can base64 decode the signature and use
666 openssl cms -verify -inform DER -in signature.der -content content.txt
668 Create an encrypted message using 128 bit Camellia:
670 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
672 Add a signer to an existing message:
674 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
676 Sign mail using RSA-PSS:
678 openssl cms -sign -in message.txt -text -out mail.msg \
679 -signer mycert.pem -keyopt rsa_padding_mode:pss
681 Create encrypted mail using RSA-OAEP:
683 openssl cms -encrypt -in plain.txt -out mail.msg \
684 -recip cert.pem -keyopt rsa_padding_mode:oaep
686 Use SHA256 KDF with an ECDH certificate:
688 openssl cms -encrypt -in plain.txt -out mail.msg \
689 -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
693 The MIME parser isn't very clever: it seems to handle most messages that I've
694 thrown at it but it may choke on others.
696 The code currently will only write out the signer's certificate to a file: if
697 the signer has a separate encryption certificate this must be manually
698 extracted. There should be some heuristic that determines the correct
699 encryption certificate.
701 Ideally a database should be maintained of a certificates for each email
704 The code doesn't currently take note of the permitted symmetric encryption
705 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
706 user has to manually include the correct encryption algorithm. It should store
707 the list of permitted ciphers in a database and only use those.
709 No revocation checking is done on the signer's certificate.
713 The use of multiple B<-signer> options and the B<-resign> command were first
714 added in OpenSSL 1.0.0
716 The B<keyopt> option was first added in OpenSSL 1.1.0
718 The use of B<-recip> to specify the recipient when encrypting mail was first
719 added to OpenSSL 1.1.0
721 Support for RSA-OAEP and RSA-PSS was first added to OpenSSL 1.1.0.
723 The use of non-RSA keys with B<-encrypt> and B<-decrypt> was first added
726 The -no_alt_chains options was first added to OpenSSL 1.1.0.
730 Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.
732 Licensed under the OpenSSL license (the "License"). You may not use
733 this file except in compliance with the License. You can obtain a copy
734 in the file LICENSE in the source distribution or at
735 L<https://www.openssl.org/source/license.html>.