22 [B<-EncryptedData_encrypt>]
24 [B<-verify_receipt receipt>]
26 [B<-inform SMIME|PEM|DER>]
27 [B<-rctform SMIME|PEM|DER>]
29 [B<-outform SMIME|PEM|DER>]
30 [B<-stream -indef -noindef>]
32 [B<-content filename>]
40 [B<-attime timestamp>]
61 [B<-verify_depth num>]
62 [B<-verify_email email>]
63 [B<-verify_hostname hostname>]
65 [B<-verify_name name>]
70 [B<-no_signer_cert_verify>]
82 [B<-receipt_request_all -receipt_request_first>]
83 [B<-receipt_request_from emailaddress>]
84 [B<-receipt_request_to emailaddress>]
85 [B<-receipt_request_print>]
88 [B<-econtent_type type>]
90 [B<-keyopt name:parameter>]
101 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
102 verify, compress and uncompress S/MIME messages.
104 =head1 COMMAND OPTIONS
106 There are fourteen operation options that set the type of operation to be
107 performed. The meaning of the other options varies according to the operation
114 encrypt mail for the given recipient certificates. Input file is the message
115 to be encrypted. The output file is the encrypted mail in MIME format. The
116 actual CMS type is <B>EnvelopedData<B>.
120 decrypt mail using the supplied certificate and private key. Expects an
121 encrypted mail message in MIME format for the input file. The decrypted mail
122 is written to the output file.
124 =item B<-debug_decrypt>
126 this option sets the B<CMS_DEBUG_DECRYPT> flag. This option should be used
127 with caution: see the notes section below.
131 sign mail using the supplied certificate and private key. Input file is
132 the message to be signed. The signed message in MIME format is written
137 verify signed mail. Expects a signed mail message on input and outputs
138 the signed data. Both clear text and opaque signing is supported.
142 takes an input message and writes out a PEM encoded CMS structure.
146 resign a message: take an existing message and one or more new signers.
148 =item B<-data_create>
150 Create a CMS B<Data> type.
154 B<Data> type and output the content.
156 =item B<-digest_create>
158 Create a CMS B<DigestedData> type.
160 =item B<-digest_verify>
162 Verify a CMS B<DigestedData> type and output the content.
166 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
167 support for this option to work, otherwise it will output an error.
171 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
172 compiled with B<zlib> support for this option to work, otherwise it will
175 =item B<-EncryptedData_encrypt>
177 Encrypt content using supplied symmetric key and algorithm using a CMS
178 B<EncrytedData> type and output the content.
180 =item B<-sign_receipt>
182 Generate and output a signed receipt for the supplied message. The input
183 message B<must> contain a signed receipt request. Functionality is otherwise
184 similar to the B<-sign> operation.
186 =item B<-verify_receipt receipt>
188 Verify a signed receipt in filename B<receipt>. The input message B<must>
189 contain the original receipt request. Functionality is otherwise similar
190 to the B<-verify> operation.
192 =item B<-in filename>
194 the input message to be encrypted or signed or the message to be decrypted
197 =item B<-inform SMIME|PEM|DER>
199 this specifies the input format for the CMS structure. The default
200 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
201 format change this to expect PEM and DER format CMS structures
202 instead. This currently only affects the input format of the CMS
203 structure, if no CMS structure is being input (for example with
204 B<-encrypt> or B<-sign>) this option has no effect.
206 =item B<-rctform SMIME|PEM|DER>
208 specify the format for a signed receipt for use with the B<-receipt_verify>
211 =item B<-out filename>
213 the message text that has been decrypted or verified or the output MIME
214 format message that has been signed or verified.
216 =item B<-outform SMIME|PEM|DER>
218 this specifies the output format for the CMS structure. The default
219 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
220 format change this to write PEM and DER format CMS structures
221 instead. This currently only affects the output format of the CMS
222 structure, if no CMS structure is being output (for example with
223 B<-verify> or B<-decrypt>) this option has no effect.
225 =item B<-stream -indef -noindef>
227 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
228 for encoding operations. This permits single pass processing of data without
229 the need to hold the entire contents in memory, potentially supporting very
230 large files. Streaming is automatically set for S/MIME signing with detached
231 data if the output format is B<SMIME> it is currently off by default for all
236 disable streaming I/O where it would produce and indefinite length constructed
237 encoding. This option currently has no effect. In future streaming will be
238 enabled by default on all relevant operations and this option will disable it.
240 =item B<-content filename>
242 This specifies a file containing the detached content, this is only
243 useful with the B<-verify> command. This is only usable if the CMS
244 structure is using the detached signature form where the content is
245 not included. This option will override any content if the input format
246 is S/MIME and it uses the multipart/signed MIME content type.
250 this option adds plain text (text/plain) MIME headers to the supplied
251 message if encrypting or signing. If decrypting or verifying it strips
252 off text headers: if the decrypted or verified message is not of MIME
253 type text/plain then an error occurs.
257 for the B<-cmsout> operation do not output the parsed CMS structure. This
258 is useful when combined with the B<-print> option or if the syntax of the CMS
259 structure is being checked.
263 for the B<-cmsout> operation print out all fields of the CMS structure. This
264 is mainly useful for testing purposes.
266 =item B<-CAfile file>
268 a file containing trusted CA certificates, only used with B<-verify>.
272 a directory containing trusted CA certificates, only used with
273 B<-verify>. This directory must be a standard certificate directory: that
274 is a hash of each subject name (using B<x509 -hash>) should be linked
279 Do not load the trusted CA certificates from the default file location
283 Do not load the trusted CA certificates from the default directory location
287 digest algorithm to use when signing or resigning. If not present then the
288 default digest algorithm for the signing key will be used (usually SHA1).
292 the encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
293 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
294 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
295 example B<-aes-128-cbc>. See L<B<enc>|enc(1)> for a list of ciphers
296 supported by your version of OpenSSL.
298 If not specified triple DES is used. Only used with B<-encrypt> and
299 B<-EncryptedData_create> commands.
303 when verifying a message normally certificates (if any) included in
304 the message are searched for the signing certificate. With this option
305 only the certificates specified in the B<-certfile> option are used.
306 The supplied certificates can still be used as untrusted CAs however.
308 =item B<-no_signer_cert_verify>
310 do not verify the signers certificate of a signed message.
314 when signing a message the signer's certificate is normally included
315 with this option it is excluded. This will reduce the size of the
316 signed message but the verifier must have a copy of the signers certificate
317 available locally (passed using the B<-certfile> option for example).
321 normally when a message is signed a set of attributes are included which
322 include the signing time and supported symmetric algorithms. With this
323 option they are not included.
327 exclude the list of supported algorithms from signed attributes, other options
328 such as signing time and content type are still included.
332 normally the input message is converted to "canonical" format which is
333 effectively using CR and LF as end of line: as required by the S/MIME
334 specification. When this option is present no translation occurs. This
335 is useful when handling binary data which may not be in MIME format.
339 when signing use ASCII CRLF format canonicalisation. This strips trailing
340 whitespace from all lines, deletes trailing blank lines at EOF and sets
341 the encapsulated content type. This option is normally used with detached
342 content and an output signature format of DER. This option is not normally
343 needed when verifying as it is enabled automatically if the encapsulated
344 content format is detected.
348 when signing a message use opaque signing: this form is more resistant
349 to translation by mail relays but it cannot be read by mail agents that
350 do not support S/MIME. Without this option cleartext signing with
351 the MIME type multipart/signed is used.
353 =item B<-certfile file>
355 allows additional certificates to be specified. When signing these will
356 be included with the message. When verifying these will be searched for
357 the signers certificates. The certificates should be in PEM format.
359 =item B<-certsout file>
361 any certificates contained in the message are written to B<file>.
363 =item B<-signer file>
365 a signing certificate when signing or resigning a message, this option can be
366 used multiple times if more than one signer is required. If a message is being
367 verified then the signers certificates will be written to this file if the
368 verification was successful.
372 when decrypting a message this specifies the recipients certificate. The
373 certificate must match one of the recipients of the message or an error
376 When encrypting a message this option may be used multiple times to specify
377 each recipient. This form B<must> be used if customised parameters are
378 required (for example to specify RSA-OAEP).
382 use subject key identifier to identify certificates instead of issuer name and
383 serial number. The supplied certificate B<must> include a subject key
384 identifier extension. Supported by B<-sign> and B<-encrypt> options.
386 =item B<-receipt_request_all -receipt_request_first>
388 for B<-sign> option include a signed receipt request. Indicate requests should
389 be provided by all recipient or first tier recipients (those mailed directly
390 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
392 =item B<-receipt_request_from emailaddress>
394 for B<-sign> option include a signed receipt request. Add an explicit email
395 address where receipts should be supplied.
397 =item B<-receipt_request_to emailaddress>
399 Add an explicit email address where signed receipts should be sent to. This
400 option B<must> but supplied if a signed receipt it requested.
402 =item B<-receipt_request_print>
404 For the B<-verify> operation print out the contents of any signed receipt
407 =item B<-secretkey key>
409 specify symmetric key to use. The key must be supplied in hex format and be
410 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
411 B<-EncryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
412 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
413 content encryption key using an AES key in the B<KEKRecipientInfo> type.
415 =item B<-secretkeyid id>
417 the key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
418 This option B<must> be present if the B<-secretkey> option is used with
419 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
420 relevant key if it is not supplied then an attempt is used to decrypt any
421 B<KEKRecipientInfo> structures.
423 =item B<-econtent_type type>
425 set the encapsulated content type to B<type> if not supplied the B<Data> type
426 is used. The B<type> argument can be any valid OID name in either text or
431 the private key to use when signing or decrypting. This must match the
432 corresponding certificate. If this option is not specified then the
433 private key must be included in the certificate file specified with
434 the B<-recip> or B<-signer> file. When signing this option can be used
435 multiple times to specify successive keys.
437 =item B<-keyopt name:opt>
439 for signing and encryption this option can be used multiple times to
440 set customised parameters for the preceding key or certificate. It can
441 currently be used to set RSA-PSS for signing, RSA-OAEP for encryption
442 or to modify default parameters for ECDH.
446 the private key password source. For more information about the format of B<arg>
447 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
449 =item B<-rand file(s)>
451 a file or files containing random data used to seed the random number
452 generator, or an EGD socket (see L<RAND_egd(3)>).
453 Multiple files can be specified separated by a OS-dependent character.
454 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
459 one or more certificates of message recipients: used when encrypting
462 =item B<-to, -from, -subject>
464 the relevant mail headers. These are included outside the signed
465 portion of a message so they may be included manually. If signing
466 then many S/MIME mail clients check the signers certificate's email
467 address matches that specified in the From: address.
469 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
470 B<explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
471 B<-inhibit_map>, B<-issuer_checks>, B<-partial_chain>, B<-policy>,
472 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
473 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-no_alt_chains>,
474 B<-use_deltas>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
475 B<-verify_ip>, B<-verify_name>, B<-x509_strict>
477 Set various certificate chain validation options. See the
478 L<verify(1)> manual page for details.
484 The MIME message must be sent without any blank lines between the
485 headers and the output. Some mail programs will automatically add
486 a blank line. Piping the mail directly to sendmail is one way to
487 achieve the correct format.
489 The supplied message to be signed or encrypted must include the
490 necessary MIME headers or many S/MIME clients wont display it
491 properly (if at all). You can use the B<-text> option to automatically
492 add plain text headers.
494 A "signed and encrypted" message is one where a signed message is
495 then encrypted. This can be produced by encrypting an already signed
496 message: see the examples section.
498 This version of the program only allows one signer per message but it
499 will verify multiple signers on received messages. Some S/MIME clients
500 choke if a message contains multiple signers. It is possible to sign
501 messages "in parallel" by signing an already signed message.
503 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
504 clients. Strictly speaking these process CMS enveloped data: CMS
505 encrypted data is used for other purposes.
507 The B<-resign> option uses an existing message digest when adding a new
508 signer. This means that attributes must be present in at least one existing
509 signer using the same message digest or this operation will fail.
511 The B<-stream> and B<-indef> options enable experimental streaming I/O support.
512 As a result the encoding is BER using indefinite length constructed encoding
513 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
514 B<-sign> operation if the content is not detached.
516 Streaming is always used for the B<-sign> operation with detached data but
517 since the content is no longer part of the CMS structure the encoding
520 If the B<-decrypt> option is used without a recipient certificate then an
521 attempt is made to locate the recipient by trying each potential recipient
522 in turn using the supplied private key. To thwart the MMA attack
523 (Bleichenbacher's attack on PKCS #1 v1.5 RSA padding) all recipients are
524 tried whether they succeed or not and if no recipients match the message
525 is "decrypted" using a random key which will typically output garbage.
526 The B<-debug_decrypt> option can be used to disable the MMA attack protection
527 and return an error if no recipient can be found: this option should be used
528 with caution. For a fuller description see L<CMS_decrypt(3)>).
536 the operation was completely successfully.
540 an error occurred parsing the command options.
544 one of the input files could not be read.
548 an error occurred creating the CMS file or when reading the MIME
553 an error occurred decrypting or verifying the message.
557 the message was verified correctly but an error occurred writing out
558 the signers certificates.
562 =head1 COMPATIBILITY WITH PKCS#7 format.
564 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
565 utility supports Cryptographic Message Syntax format. Use of some features
566 will result in messages which cannot be processed by applications which only
567 support the older format. These are detailed below.
569 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
571 The B<-outform PEM> option uses different headers.
573 The B<-compress> option.
575 The B<-secretkey> option when used with B<-encrypt>.
577 The use of PSS with B<-sign>.
579 The use of OAEP or non-RSA keys with B<-encrypt>.
581 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
582 be processed by the older B<smime> command.
586 Create a cleartext signed message:
588 openssl cms -sign -in message.txt -text -out mail.msg \
591 Create an opaque signed message
593 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
596 Create a signed message, include some additional certificates and
597 read the private key from another file:
599 openssl cms -sign -in in.txt -text -out mail.msg \
600 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
602 Create a signed message with two signers, use key identifier:
604 openssl cms -sign -in message.txt -text -out mail.msg \
605 -signer mycert.pem -signer othercert.pem -keyid
607 Send a signed message under Unix directly to sendmail, including headers:
609 openssl cms -sign -in in.txt -text -signer mycert.pem \
610 -from steve@openssl.org -to someone@somewhere \
611 -subject "Signed message" | sendmail someone@somewhere
613 Verify a message and extract the signer's certificate if successful:
615 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
617 Send encrypted mail using triple DES:
619 openssl cms -encrypt -in in.txt -from steve@openssl.org \
620 -to someone@somewhere -subject "Encrypted message" \
621 -des3 user.pem -out mail.msg
623 Sign and encrypt mail:
625 openssl cms -sign -in ml.txt -signer my.pem -text \
626 | openssl cms -encrypt -out mail.msg \
627 -from steve@openssl.org -to someone@somewhere \
628 -subject "Signed and Encrypted message" -des3 user.pem
630 Note: the encryption command does not include the B<-text> option because the
631 message being encrypted already has MIME headers.
635 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
637 The output from Netscape form signing is a PKCS#7 structure with the
638 detached signature format. You can use this program to verify the
639 signature by line wrapping the base64 encoded structure and surrounding
642 -----BEGIN PKCS7-----
645 and using the command,
647 openssl cms -verify -inform PEM -in signature.pem -content content.txt
649 alternatively you can base64 decode the signature and use
651 openssl cms -verify -inform DER -in signature.der -content content.txt
653 Create an encrypted message using 128 bit Camellia:
655 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
657 Add a signer to an existing message:
659 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
661 Sign mail using RSA-PSS:
663 openssl cms -sign -in message.txt -text -out mail.msg \
664 -signer mycert.pem -keyopt rsa_padding_mode:pss
666 Create encrypted mail using RSA-OAEP:
668 openssl cms -encrypt -in plain.txt -out mail.msg \
669 -recip cert.pem -keyopt rsa_padding_mode:oaep
671 Use SHA256 KDF with an ECDH certificate:
673 openssl cms -encrypt -in plain.txt -out mail.msg \
674 -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
678 The MIME parser isn't very clever: it seems to handle most messages that I've
679 thrown at it but it may choke on others.
681 The code currently will only write out the signer's certificate to a file: if
682 the signer has a separate encryption certificate this must be manually
683 extracted. There should be some heuristic that determines the correct
684 encryption certificate.
686 Ideally a database should be maintained of a certificates for each email
689 The code doesn't currently take note of the permitted symmetric encryption
690 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
691 user has to manually include the correct encryption algorithm. It should store
692 the list of permitted ciphers in a database and only use those.
694 No revocation checking is done on the signer's certificate.
698 The use of multiple B<-signer> options and the B<-resign> command were first
699 added in OpenSSL 1.0.0
701 The B<keyopt> option was first added in OpenSSL 1.1.0
703 The use of B<-recip> to specify the recipient when encrypting mail was first
704 added to OpenSSL 1.1.0
706 Support for RSA-OAEP and RSA-PSS was first added to OpenSSL 1.1.0.
708 The use of non-RSA keys with B<-encrypt> and B<-decrypt> was first added
711 The -no_alt_chains options was first added to OpenSSL 1.1.0.