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>]
52 [B<-receipt_request_all -receipt_request_first>]
53 [B<-receipt_request_from emailaddress>]
54 [B<-receipt_request_to emailaddress>]
55 [B<-receipt_request_print>]
58 [B<-econtent_type type>]
70 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
71 verify, compress and uncompress S/MIME messages.
73 =head1 COMMAND OPTIONS
75 There are fourteen operation options that set the type of operation to be
76 performed. The meaning of the other options varies according to the operation
83 encrypt mail for the given recipient certificates. Input file is the message
84 to be encrypted. The output file is the encrypted mail in MIME format. The
85 actual CMS type is <B>EnvelopedData<B>.
89 decrypt mail using the supplied certificate and private key. Expects an
90 encrypted mail message in MIME format for the input file. The decrypted mail
91 is written to the output file.
95 sign mail using the supplied certificate and private key. Input file is
96 the message to be signed. The signed message in MIME format is written
101 verify signed mail. Expects a signed mail message on input and outputs
102 the signed data. Both clear text and opaque signing is supported.
106 takes an input message and writes out a PEM encoded CMS structure.
110 resign a message: take an existing message and one or more new signers.
112 =item B<-data_create>
114 Create a CMS B<Data> type.
118 B<Data> type and output the content.
120 =item B<-digest_create>
122 Create a CMS B<DigestedData> type.
124 =item B<-digest_verify>
126 Verify a CMS B<DigestedData> type and output the content.
130 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
131 support for this option to work, otherwise it will output an error.
135 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
136 compiled with B<zlib> support for this option to work, otherwise it will
139 =item B<-EncryptedData_encrypt>
141 Encrypt suppled content using supplied symmetric key and algorithm using a CMS
142 B<EncrytedData> type and output the content.
144 =item B<-sign_receipt>
146 Generate and output a signed receipt for the supplied message. The input
147 message B<must> contain a signed receipt request. Functionality is otherwise
148 similar to the B<-sign> operation.
150 =item B<-verify_receipt receipt>
152 Verify a signed receipt in filename B<receipt>. The input message B<must>
153 contain the original receipt request. Functionality is otherwise similar
154 to the B<-verify> operation.
156 =item B<-in filename>
158 the input message to be encrypted or signed or the message to be decrypted
161 =item B<-inform SMIME|PEM|DER>
163 this specifies the input format for the CMS structure. The default
164 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
165 format change this to expect PEM and DER format CMS structures
166 instead. This currently only affects the input format of the CMS
167 structure, if no CMS structure is being input (for example with
168 B<-encrypt> or B<-sign>) this option has no effect.
170 =item B<-rctform SMIME|PEM|DER>
172 specify the format for a signed receipt for use with the B<-receipt_verify>
175 =item B<-out filename>
177 the message text that has been decrypted or verified or the output MIME
178 format message that has been signed or verified.
180 =item B<-outform SMIME|PEM|DER>
182 this specifies the output format for the CMS structure. The default
183 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
184 format change this to write PEM and DER format CMS structures
185 instead. This currently only affects the output format of the CMS
186 structure, if no CMS structure is being output (for example with
187 B<-verify> or B<-decrypt>) this option has no effect.
189 =item B<-stream -indef -noindef>
191 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
192 for encoding operations. This permits single pass processing of data without
193 the need to hold the entire contents in memory, potentially supporting very
194 large files. Streaming is automatically set for S/MIME signing with detached
195 data if the output format is B<SMIME> it is currently off by default for all
200 disable streaming I/O where it would produce and indefinite length constructed
201 encoding. This option currently has no effect. In future streaming will be
202 enabled by default on all relevant operations and this option will disable it.
204 =item B<-content filename>
206 This specifies a file containing the detached content, this is only
207 useful with the B<-verify> command. This is only usable if the CMS
208 structure is using the detached signature form where the content is
209 not included. This option will override any content if the input format
210 is S/MIME and it uses the multipart/signed MIME content type.
214 this option adds plain text (text/plain) MIME headers to the supplied
215 message if encrypting or signing. If decrypting or verifying it strips
216 off text headers: if the decrypted or verified message is not of MIME
217 type text/plain then an error occurs.
221 for the B<-cmsout> operation do not output the parsed CMS structure. This
222 is useful when combined with the B<-print> option or if the syntax of the CMS
223 structure is being checked.
227 for the B<-cmsout> operation print out all fields of the CMS structure. This
228 is mainly useful for testing purposes.
230 =item B<-CAfile file>
232 a file containing trusted CA certificates, only used with B<-verify>.
236 a directory containing trusted CA certificates, only used with
237 B<-verify>. This directory must be a standard certificate directory: that
238 is a hash of each subject name (using B<x509 -hash>) should be linked
243 digest algorithm to use when signing or resigning. If not present then the
244 default digest algorithm for the signing key will be used (usually SHA1).
248 the encryption algorithm to use. For example triple DES (168 bits) - B<-des3>
249 or 256 bit AES - B<-aes256>. Any standard algorithm name (as used by the
250 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
251 example B<-aes_128_cbc>. See L<B<enc>|enc(1)> for a list of ciphers
252 supported by your version of OpenSSL.
254 If not specified triple DES is used. Only used with B<-encrypt> and
255 B<-EncryptedData_create> commands.
259 when verifying a message normally certificates (if any) included in
260 the message are searched for the signing certificate. With this option
261 only the certificates specified in the B<-certfile> option are used.
262 The supplied certificates can still be used as untrusted CAs however.
264 =item B<-no_signer_cert_verify>
266 do not verify the signers certificate of a signed message.
270 when signing a message the signer's certificate is normally included
271 with this option it is excluded. This will reduce the size of the
272 signed message but the verifier must have a copy of the signers certificate
273 available locally (passed using the B<-certfile> option for example).
277 normally when a message is signed a set of attributes are included which
278 include the signing time and supported symmetric algorithms. With this
279 option they are not included.
283 exclude the list of supported algorithms from signed attributes, other options
284 such as signing time and content type are still included.
288 normally the input message is converted to "canonical" format which is
289 effectively using CR and LF as end of line: as required by the S/MIME
290 specification. When this option is present no translation occurs. This
291 is useful when handling binary data which may not be in MIME format.
295 when signing a message use opaque signing: this form is more resistant
296 to translation by mail relays but it cannot be read by mail agents that
297 do not support S/MIME. Without this option cleartext signing with
298 the MIME type multipart/signed is used.
300 =item B<-certfile file>
302 allows additional certificates to be specified. When signing these will
303 be included with the message. When verifying these will be searched for
304 the signers certificates. The certificates should be in PEM format.
306 =item B<-certsout file>
308 any certificates contained in the message are written to B<file>.
310 =item B<-signer file>
312 a signing certificate when signing or resigning a message, this option can be
313 used multiple times if more than one signer is required. If a message is being
314 verified then the signers certificates will be written to this file if the
315 verification was successful.
319 the recipients certificate when decrypting a message. This certificate
320 must match one of the recipients of the message or an error occurs.
324 use subject key identifier to identify certificates instead of issuer name and
325 serial number. The supplied certificate B<must> include a subject key
326 identifier extension. Supported by B<-sign> and B<-encrypt> options.
328 =item B<-receipt_request_all -receipt_request_first>
330 for B<-sign> option include a signed receipt request. Indicate requests should
331 be provided by all receipient or first tier recipients (those mailed directly
332 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
334 =item B<-receipt_request_from emailaddress>
336 for B<-sign> option include a signed receipt request. Add an explicit email
337 address where receipts should be supplied.
339 =item B<-receipt_request_to emailaddress>
341 Add an explicit email address where signed receipts should be sent to. This
342 option B<must> but supplied if a signed receipt it requested.
344 =item B<-receipt_request_print>
346 For the B<-verify> operation print out the contents of any signed receipt
349 =item B<-secretkey key>
351 specify symmetric key to use. The key must be supplied in hex format and be
352 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
353 B<-EncrryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
354 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
355 content encryption key using an AES key in the B<KEKRecipientInfo> type.
357 =item B<-secretkeyid id>
359 the key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
360 This option B<must> be present if the B<-secretkey> option is used with
361 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
362 relevant key if it is not supplied then an attempt is used to decrypt any
363 B<KEKRecipientInfo> structures.
365 =item B<-econtent_type type>
367 set the encapsulated content type to B<type> if not supplied the B<Data> type
368 is used. The B<type> argument can be any valid OID name in either text or
373 the private key to use when signing or decrypting. This must match the
374 corresponding certificate. If this option is not specified then the
375 private key must be included in the certificate file specified with
376 the B<-recip> or B<-signer> file. When signing this option can be used
377 multiple times to specify successive keys.
381 the private key password source. For more information about the format of B<arg>
382 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
384 =item B<-rand file(s)>
386 a file or files containing random data used to seed the random number
387 generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
388 Multiple files can be specified separated by a OS-dependent character.
389 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
394 one or more certificates of message recipients: used when encrypting
397 =item B<-to, -from, -subject>
399 the relevant mail headers. These are included outside the signed
400 portion of a message so they may be included manually. If signing
401 then many S/MIME mail clients check the signers certificate's email
402 address matches that specified in the From: address.
404 =item B<-purpose, -ignore_critical, -issuer_checks, -crl_check, -crl_check_all, -policy_check, -extended_crl, -x509_strict, -policy -check_ss_sig>
406 Set various certificate chain valiadition option. See the
407 L<B<verify>|verify(1)> manual page for details.
413 The MIME message must be sent without any blank lines between the
414 headers and the output. Some mail programs will automatically add
415 a blank line. Piping the mail directly to sendmail is one way to
416 achieve the correct format.
418 The supplied message to be signed or encrypted must include the
419 necessary MIME headers or many S/MIME clients wont display it
420 properly (if at all). You can use the B<-text> option to automatically
421 add plain text headers.
423 A "signed and encrypted" message is one where a signed message is
424 then encrypted. This can be produced by encrypting an already signed
425 message: see the examples section.
427 This version of the program only allows one signer per message but it
428 will verify multiple signers on received messages. Some S/MIME clients
429 choke if a message contains multiple signers. It is possible to sign
430 messages "in parallel" by signing an already signed message.
432 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
433 clients. Strictly speaking these process CMS enveloped data: CMS
434 encrypted data is used for other purposes.
436 The B<-resign> option uses an existing message digest when adding a new
437 signer. This means that attributes must be present in at least one existing
438 signer using the same message digest or this operation will fail.
440 The B<-stream> and B<-indef> options enable experimental streaming I/O support.
441 As a result the encoding is BER using indefinite length constructed encoding
442 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
443 B<-sign> operation if the content is not detached.
445 Streaming is always used for the B<-sign> operation with detached data but
446 since the content is no longer part of the CMS structure the encoding
455 the operation was completely successfully.
459 an error occurred parsing the command options.
463 one of the input files could not be read.
467 an error occurred creating the CMS file or when reading the MIME
472 an error occurred decrypting or verifying the message.
476 the message was verified correctly but an error occurred writing out
477 the signers certificates.
481 =head1 COMPATIBILITY WITH PKCS#7 format.
483 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
484 utility supports Cryptographic Message Syntax format. Use of some features
485 will result in messages which cannot be processed by applications which only
486 support the older format. These are detailed below.
488 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
490 The B<-outform PEM> option uses different headers.
492 The B<-compress> option.
494 The B<-secretkey> option when used with B<-encrypt>.
496 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
497 be processed by the older B<smime> command.
501 Create a cleartext signed message:
503 openssl cms -sign -in message.txt -text -out mail.msg \
506 Create an opaque signed message
508 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
511 Create a signed message, include some additional certificates and
512 read the private key from another file:
514 openssl cms -sign -in in.txt -text -out mail.msg \
515 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
517 Create a signed message with two signers, use key identifier:
519 openssl cms -sign -in message.txt -text -out mail.msg \
520 -signer mycert.pem -signer othercert.pem -keyid
522 Send a signed message under Unix directly to sendmail, including headers:
524 openssl cms -sign -in in.txt -text -signer mycert.pem \
525 -from steve@openssl.org -to someone@somewhere \
526 -subject "Signed message" | sendmail someone@somewhere
528 Verify a message and extract the signer's certificate if successful:
530 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
532 Send encrypted mail using triple DES:
534 openssl cms -encrypt -in in.txt -from steve@openssl.org \
535 -to someone@somewhere -subject "Encrypted message" \
536 -des3 user.pem -out mail.msg
538 Sign and encrypt mail:
540 openssl cms -sign -in ml.txt -signer my.pem -text \
541 | openssl cms -encrypt -out mail.msg \
542 -from steve@openssl.org -to someone@somewhere \
543 -subject "Signed and Encrypted message" -des3 user.pem
545 Note: the encryption command does not include the B<-text> option because the
546 message being encrypted already has MIME headers.
550 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
552 The output from Netscape form signing is a PKCS#7 structure with the
553 detached signature format. You can use this program to verify the
554 signature by line wrapping the base64 encoded structure and surrounding
557 -----BEGIN PKCS7-----
560 and using the command,
562 openssl cms -verify -inform PEM -in signature.pem -content content.txt
564 alternatively you can base64 decode the signature and use
566 openssl cms -verify -inform DER -in signature.der -content content.txt
568 Create an encrypted message using 128 bit Camellia:
570 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
572 Add a signer to an existing message:
574 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
578 The MIME parser isn't very clever: it seems to handle most messages that I've
579 thrown at it but it may choke on others.
581 The code currently will only write out the signer's certificate to a file: if
582 the signer has a separate encryption certificate this must be manually
583 extracted. There should be some heuristic that determines the correct
584 encryption certificate.
586 Ideally a database should be maintained of a certificates for each email
589 The code doesn't currently take note of the permitted symmetric encryption
590 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
591 user has to manually include the correct encryption algorithm. It should store
592 the list of permitted ciphers in a database and only use those.
594 No revocation checking is done on the signer's certificate.
598 The use of multiple B<-signer> options and the B<-resign> command were first
599 added in OpenSSL 1.0.0