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>]
41 [B<-no_signer_cert_verify>]
53 [B<-receipt_request_all -receipt_request_first>]
54 [B<-receipt_request_from emailaddress>]
55 [B<-receipt_request_to emailaddress>]
56 [B<-receipt_request_print>]
59 [B<-econtent_type type>]
61 [B<-keyopt name:parameter>]
72 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
73 verify, compress and uncompress S/MIME messages.
75 =head1 COMMAND OPTIONS
77 There are fourteen operation options that set the type of operation to be
78 performed. The meaning of the other options varies according to the operation
85 encrypt mail for the given recipient certificates. Input file is the message
86 to be encrypted. The output file is the encrypted mail in MIME format. The
87 actual CMS type is <B>EnvelopedData<B>.
91 decrypt mail using the supplied certificate and private key. Expects an
92 encrypted mail message in MIME format for the input file. The decrypted mail
93 is written to the output file.
97 sign mail using the supplied certificate and private key. Input file is
98 the message to be signed. The signed message in MIME format is written
103 verify signed mail. Expects a signed mail message on input and outputs
104 the signed data. Both clear text and opaque signing is supported.
108 takes an input message and writes out a PEM encoded CMS structure.
112 resign a message: take an existing message and one or more new signers.
114 =item B<-data_create>
116 Create a CMS B<Data> type.
120 B<Data> type and output the content.
122 =item B<-digest_create>
124 Create a CMS B<DigestedData> type.
126 =item B<-digest_verify>
128 Verify a CMS B<DigestedData> type and output the content.
132 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
133 support for this option to work, otherwise it will output an error.
137 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
138 compiled with B<zlib> support for this option to work, otherwise it will
141 =item B<-EncryptedData_encrypt>
143 Encrypt suppled content using supplied symmetric key and algorithm using a CMS
144 B<EncrytedData> type and output the content.
146 =item B<-sign_receipt>
148 Generate and output a signed receipt for the supplied message. The input
149 message B<must> contain a signed receipt request. Functionality is otherwise
150 similar to the B<-sign> operation.
152 =item B<-verify_receipt receipt>
154 Verify a signed receipt in filename B<receipt>. The input message B<must>
155 contain the original receipt request. Functionality is otherwise similar
156 to the B<-verify> operation.
158 =item B<-in filename>
160 the input message to be encrypted or signed or the message to be decrypted
163 =item B<-inform SMIME|PEM|DER>
165 this specifies the input format for the CMS structure. The default
166 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
167 format change this to expect PEM and DER format CMS structures
168 instead. This currently only affects the input format of the CMS
169 structure, if no CMS structure is being input (for example with
170 B<-encrypt> or B<-sign>) this option has no effect.
172 =item B<-rctform SMIME|PEM|DER>
174 specify the format for a signed receipt for use with the B<-receipt_verify>
177 =item B<-out filename>
179 the message text that has been decrypted or verified or the output MIME
180 format message that has been signed or verified.
182 =item B<-outform SMIME|PEM|DER>
184 this specifies the output format for the CMS structure. The default
185 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
186 format change this to write PEM and DER format CMS structures
187 instead. This currently only affects the output format of the CMS
188 structure, if no CMS structure is being output (for example with
189 B<-verify> or B<-decrypt>) this option has no effect.
191 =item B<-stream -indef -noindef>
193 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
194 for encoding operations. This permits single pass processing of data without
195 the need to hold the entire contents in memory, potentially supporting very
196 large files. Streaming is automatically set for S/MIME signing with detached
197 data if the output format is B<SMIME> it is currently off by default for all
202 disable streaming I/O where it would produce and indefinite length constructed
203 encoding. This option currently has no effect. In future streaming will be
204 enabled by default on all relevant operations and this option will disable it.
206 =item B<-content filename>
208 This specifies a file containing the detached content, this is only
209 useful with the B<-verify> command. This is only usable if the CMS
210 structure is using the detached signature form where the content is
211 not included. This option will override any content if the input format
212 is S/MIME and it uses the multipart/signed MIME content type.
216 this option adds plain text (text/plain) MIME headers to the supplied
217 message if encrypting or signing. If decrypting or verifying it strips
218 off text headers: if the decrypted or verified message is not of MIME
219 type text/plain then an error occurs.
223 for the B<-cmsout> operation do not output the parsed CMS structure. This
224 is useful when combined with the B<-print> option or if the syntax of the CMS
225 structure is being checked.
229 for the B<-cmsout> operation print out all fields of the CMS structure. This
230 is mainly useful for testing purposes.
232 =item B<-CAfile file>
234 a file containing trusted CA certificates, only used with B<-verify>.
238 a directory containing trusted CA certificates, only used with
239 B<-verify>. This directory must be a standard certificate directory: that
240 is a hash of each subject name (using B<x509 -hash>) should be linked
245 digest algorithm to use when signing or resigning. If not present then the
246 default digest algorithm for the signing key will be used (usually SHA1).
250 the encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
251 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
252 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
253 example B<-aes_128_cbc>. See L<B<enc>|enc(1)> for a list of ciphers
254 supported by your version of OpenSSL.
256 If not specified triple DES is used. Only used with B<-encrypt> and
257 B<-EncryptedData_create> commands.
261 when verifying a message normally certificates (if any) included in
262 the message are searched for the signing certificate. With this option
263 only the certificates specified in the B<-certfile> option are used.
264 The supplied certificates can still be used as untrusted CAs however.
266 =item B<-no_signer_cert_verify>
268 do not verify the signers certificate of a signed message.
272 when signing a message the signer's certificate is normally included
273 with this option it is excluded. This will reduce the size of the
274 signed message but the verifier must have a copy of the signers certificate
275 available locally (passed using the B<-certfile> option for example).
279 normally when a message is signed a set of attributes are included which
280 include the signing time and supported symmetric algorithms. With this
281 option they are not included.
285 exclude the list of supported algorithms from signed attributes, other options
286 such as signing time and content type are still included.
290 normally the input message is converted to "canonical" format which is
291 effectively using CR and LF as end of line: as required by the S/MIME
292 specification. When this option is present no translation occurs. This
293 is useful when handling binary data which may not be in MIME format.
297 when signing use ASCII CRLF format canonicalisation. This strips trailing
298 whitespace from all lines, deletes trailing blank lines at EOF and sets
299 the encapsulated content type. This option is normally used with detached
300 content and an output signature format of DER. This option is not normally
301 needed when verifying as it is enabled automatically if the encapsulated
302 content format is detected.
306 when signing a message use opaque signing: this form is more resistant
307 to translation by mail relays but it cannot be read by mail agents that
308 do not support S/MIME. Without this option cleartext signing with
309 the MIME type multipart/signed is used.
311 =item B<-certfile file>
313 allows additional certificates to be specified. When signing these will
314 be included with the message. When verifying these will be searched for
315 the signers certificates. The certificates should be in PEM format.
317 =item B<-certsout file>
319 any certificates contained in the message are written to B<file>.
321 =item B<-signer file>
323 a signing certificate when signing or resigning a message, this option can be
324 used multiple times if more than one signer is required. If a message is being
325 verified then the signers certificates will be written to this file if the
326 verification was successful.
330 when decrypting a message this specifies the recipients certificate. The
331 certificate must match one of the recipients of the message or an error
334 When encrypting a message this option may be used multiple times to specify
335 each recipient. This form B<must> be used if customised parameters are
336 required (for example to specify RSA-OAEP).
340 use subject key identifier to identify certificates instead of issuer name and
341 serial number. The supplied certificate B<must> include a subject key
342 identifier extension. Supported by B<-sign> and B<-encrypt> options.
344 =item B<-receipt_request_all -receipt_request_first>
346 for B<-sign> option include a signed receipt request. Indicate requests should
347 be provided by all receipient or first tier recipients (those mailed directly
348 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
350 =item B<-receipt_request_from emailaddress>
352 for B<-sign> option include a signed receipt request. Add an explicit email
353 address where receipts should be supplied.
355 =item B<-receipt_request_to emailaddress>
357 Add an explicit email address where signed receipts should be sent to. This
358 option B<must> but supplied if a signed receipt it requested.
360 =item B<-receipt_request_print>
362 For the B<-verify> operation print out the contents of any signed receipt
365 =item B<-secretkey key>
367 specify symmetric key to use. The key must be supplied in hex format and be
368 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
369 B<-EncrryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
370 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
371 content encryption key using an AES key in the B<KEKRecipientInfo> type.
373 =item B<-secretkeyid id>
375 the key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
376 This option B<must> be present if the B<-secretkey> option is used with
377 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
378 relevant key if it is not supplied then an attempt is used to decrypt any
379 B<KEKRecipientInfo> structures.
381 =item B<-econtent_type type>
383 set the encapsulated content type to B<type> if not supplied the B<Data> type
384 is used. The B<type> argument can be any valid OID name in either text or
389 the private key to use when signing or decrypting. This must match the
390 corresponding certificate. If this option is not specified then the
391 private key must be included in the certificate file specified with
392 the B<-recip> or B<-signer> file. When signing this option can be used
393 multiple times to specify successive keys.
395 =item B<-keyopt name:opt>
397 for signing and encryption this option can be used multiple times to
398 set customised parameters for the preceding key or certificate. It can
399 currently be used to set RSA-PSS for signing, RSA-OAEP for encryption
400 or to modify default parameters for ECDH.
404 the private key password source. For more information about the format of B<arg>
405 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
407 =item B<-rand file(s)>
409 a file or files containing random data used to seed the random number
410 generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
411 Multiple files can be specified separated by a OS-dependent character.
412 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
417 one or more certificates of message recipients: used when encrypting
420 =item B<-to, -from, -subject>
422 the relevant mail headers. These are included outside the signed
423 portion of a message so they may be included manually. If signing
424 then many S/MIME mail clients check the signers certificate's email
425 address matches that specified in the From: address.
427 =item B<-purpose, -ignore_critical, -issuer_checks, -crl_check, -crl_check_all, -policy_check, -extended_crl, -x509_strict, -policy -check_ss_sig>
429 Set various certificate chain valiadition option. See the
430 L<B<verify>|verify(1)> manual page for details.
436 The MIME message must be sent without any blank lines between the
437 headers and the output. Some mail programs will automatically add
438 a blank line. Piping the mail directly to sendmail is one way to
439 achieve the correct format.
441 The supplied message to be signed or encrypted must include the
442 necessary MIME headers or many S/MIME clients wont display it
443 properly (if at all). You can use the B<-text> option to automatically
444 add plain text headers.
446 A "signed and encrypted" message is one where a signed message is
447 then encrypted. This can be produced by encrypting an already signed
448 message: see the examples section.
450 This version of the program only allows one signer per message but it
451 will verify multiple signers on received messages. Some S/MIME clients
452 choke if a message contains multiple signers. It is possible to sign
453 messages "in parallel" by signing an already signed message.
455 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
456 clients. Strictly speaking these process CMS enveloped data: CMS
457 encrypted data is used for other purposes.
459 The B<-resign> option uses an existing message digest when adding a new
460 signer. This means that attributes must be present in at least one existing
461 signer using the same message digest or this operation will fail.
463 The B<-stream> and B<-indef> options enable experimental streaming I/O support.
464 As a result the encoding is BER using indefinite length constructed encoding
465 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
466 B<-sign> operation if the content is not detached.
468 Streaming is always used for the B<-sign> operation with detached data but
469 since the content is no longer part of the CMS structure the encoding
478 the operation was completely successfully.
482 an error occurred parsing the command options.
486 one of the input files could not be read.
490 an error occurred creating the CMS file or when reading the MIME
495 an error occurred decrypting or verifying the message.
499 the message was verified correctly but an error occurred writing out
500 the signers certificates.
504 =head1 COMPATIBILITY WITH PKCS#7 format.
506 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
507 utility supports Cryptographic Message Syntax format. Use of some features
508 will result in messages which cannot be processed by applications which only
509 support the older format. These are detailed below.
511 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
513 The B<-outform PEM> option uses different headers.
515 The B<-compress> option.
517 The B<-secretkey> option when used with B<-encrypt>.
519 The use of PSS with B<-sign>.
521 The use of OAEP or non-RSA keys with B<-encrypt>.
523 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
524 be processed by the older B<smime> command.
528 Create a cleartext signed message:
530 openssl cms -sign -in message.txt -text -out mail.msg \
533 Create an opaque signed message
535 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
538 Create a signed message, include some additional certificates and
539 read the private key from another file:
541 openssl cms -sign -in in.txt -text -out mail.msg \
542 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
544 Create a signed message with two signers, use key identifier:
546 openssl cms -sign -in message.txt -text -out mail.msg \
547 -signer mycert.pem -signer othercert.pem -keyid
549 Send a signed message under Unix directly to sendmail, including headers:
551 openssl cms -sign -in in.txt -text -signer mycert.pem \
552 -from steve@openssl.org -to someone@somewhere \
553 -subject "Signed message" | sendmail someone@somewhere
555 Verify a message and extract the signer's certificate if successful:
557 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
559 Send encrypted mail using triple DES:
561 openssl cms -encrypt -in in.txt -from steve@openssl.org \
562 -to someone@somewhere -subject "Encrypted message" \
563 -des3 user.pem -out mail.msg
565 Sign and encrypt mail:
567 openssl cms -sign -in ml.txt -signer my.pem -text \
568 | openssl cms -encrypt -out mail.msg \
569 -from steve@openssl.org -to someone@somewhere \
570 -subject "Signed and Encrypted message" -des3 user.pem
572 Note: the encryption command does not include the B<-text> option because the
573 message being encrypted already has MIME headers.
577 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
579 The output from Netscape form signing is a PKCS#7 structure with the
580 detached signature format. You can use this program to verify the
581 signature by line wrapping the base64 encoded structure and surrounding
584 -----BEGIN PKCS7-----
587 and using the command,
589 openssl cms -verify -inform PEM -in signature.pem -content content.txt
591 alternatively you can base64 decode the signature and use
593 openssl cms -verify -inform DER -in signature.der -content content.txt
595 Create an encrypted message using 128 bit Camellia:
597 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
599 Add a signer to an existing message:
601 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
603 Sign mail using RSA-PSS:
605 openssl cms -sign -in message.txt -text -out mail.msg \
606 -signer mycert.pem -keyopt rsa_padding_mode:pss
608 Create encrypted mail using RSA-OAEP:
610 openssl cms -encrypt -in plain.txt -out mail.msg \
611 -recip cert.pem -keyopt rsa_padding_mode:oaep
613 Use SHA256 KDF with an ECDH certificate:
615 openssl cms -encrypt -in plain.txt -out mail.msg \
616 -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256
620 The MIME parser isn't very clever: it seems to handle most messages that I've
621 thrown at it but it may choke on others.
623 The code currently will only write out the signer's certificate to a file: if
624 the signer has a separate encryption certificate this must be manually
625 extracted. There should be some heuristic that determines the correct
626 encryption certificate.
628 Ideally a database should be maintained of a certificates for each email
631 The code doesn't currently take note of the permitted symmetric encryption
632 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
633 user has to manually include the correct encryption algorithm. It should store
634 the list of permitted ciphers in a database and only use those.
636 No revocation checking is done on the signer's certificate.
640 The use of multiple B<-signer> options and the B<-resign> command were first
641 added in OpenSSL 1.0.0
643 The B<keyopt> option was first added in OpenSSL 1.1.0
645 The use of B<-recip> to specify the recipient when encrypting mail was first
646 added to OpenSSL 1.1.0
648 Support for RSA-OAEP and RSA-PSS was first added to OpenSSL 1.1.0.
650 The use of non-RSA keys with B<-encrypt> and B<-decrypt> was first added