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>]
51 [B<-no_signer_cert_verify>]
62 [B<-receipt_request_all -receipt_request_first>]
63 [B<-receipt_request_from emailaddress>]
64 [B<-receipt_request_to emailaddress>]
65 [B<-receipt_request_print>]
68 [B<-econtent_type type>]
80 The B<cms> command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and
81 verify, compress and uncompress S/MIME messages.
83 =head1 COMMAND OPTIONS
85 There are fourteen operation options that set the type of operation to be
86 performed. The meaning of the other options varies according to the operation
93 encrypt mail for the given recipient certificates. Input file is the message
94 to be encrypted. The output file is the encrypted mail in MIME format. The
95 actual CMS type is <B>EnvelopedData<B>.
99 decrypt mail using the supplied certificate and private key. Expects an
100 encrypted mail message in MIME format for the input file. The decrypted mail
101 is written to the output file.
105 sign mail using the supplied certificate and private key. Input file is
106 the message to be signed. The signed message in MIME format is written
111 verify signed mail. Expects a signed mail message on input and outputs
112 the signed data. Both clear text and opaque signing is supported.
116 takes an input message and writes out a PEM encoded CMS structure.
120 resign a message: take an existing message and one or more new signers.
122 =item B<-data_create>
124 Create a CMS B<Data> type.
128 B<Data> type and output the content.
130 =item B<-digest_create>
132 Create a CMS B<DigestedData> type.
134 =item B<-digest_verify>
136 Verify a CMS B<DigestedData> type and output the content.
140 Create a CMS B<CompressedData> type. OpenSSL must be compiled with B<zlib>
141 support for this option to work, otherwise it will output an error.
145 Uncompress a CMS B<CompressedData> type and output the content. OpenSSL must be
146 compiled with B<zlib> support for this option to work, otherwise it will
149 =item B<-EncryptedData_encrypt>
151 Encrypt suppled content using supplied symmetric key and algorithm using a CMS
152 B<EncrytedData> type and output the content.
154 =item B<-sign_receipt>
156 Generate and output a signed receipt for the supplied message. The input
157 message B<must> contain a signed receipt request. Functionality is otherwise
158 similar to the B<-sign> operation.
160 =item B<-verify_receipt receipt>
162 Verify a signed receipt in filename B<receipt>. The input message B<must>
163 contain the original receipt request. Functionality is otherwise similar
164 to the B<-verify> operation.
166 =item B<-in filename>
168 the input message to be encrypted or signed or the message to be decrypted
171 =item B<-inform SMIME|PEM|DER>
173 this specifies the input format for the CMS structure. The default
174 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
175 format change this to expect PEM and DER format CMS structures
176 instead. This currently only affects the input format of the CMS
177 structure, if no CMS structure is being input (for example with
178 B<-encrypt> or B<-sign>) this option has no effect.
180 =item B<-rctform SMIME|PEM|DER>
182 specify the format for a signed receipt for use with the B<-receipt_verify>
185 =item B<-out filename>
187 the message text that has been decrypted or verified or the output MIME
188 format message that has been signed or verified.
190 =item B<-outform SMIME|PEM|DER>
192 this specifies the output format for the CMS structure. The default
193 is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER>
194 format change this to write PEM and DER format CMS structures
195 instead. This currently only affects the output format of the CMS
196 structure, if no CMS structure is being output (for example with
197 B<-verify> or B<-decrypt>) this option has no effect.
199 =item B<-stream -indef -noindef>
201 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
202 for encoding operations. This permits single pass processing of data without
203 the need to hold the entire contents in memory, potentially supporting very
204 large files. Streaming is automatically set for S/MIME signing with detached
205 data if the output format is B<SMIME> it is currently off by default for all
210 disable streaming I/O where it would produce and indefinite length constructed
211 encoding. This option currently has no effect. In future streaming will be
212 enabled by default on all relevant operations and this option will disable it.
214 =item B<-content filename>
216 This specifies a file containing the detached content, this is only
217 useful with the B<-verify> command. This is only usable if the CMS
218 structure is using the detached signature form where the content is
219 not included. This option will override any content if the input format
220 is S/MIME and it uses the multipart/signed MIME content type.
224 this option adds plain text (text/plain) MIME headers to the supplied
225 message if encrypting or signing. If decrypting or verifying it strips
226 off text headers: if the decrypted or verified message is not of MIME
227 type text/plain then an error occurs.
231 for the B<-cmsout> operation do not output the parsed CMS structure. This
232 is useful when combined with the B<-print> option or if the syntax of the CMS
233 structure is being checked.
237 for the B<-cmsout> operation print out all fields of the CMS structure. This
238 is mainly useful for testing purposes.
240 =item B<-CAfile file>
242 a file containing trusted CA certificates, only used with B<-verify>.
246 a directory containing trusted CA certificates, only used with
247 B<-verify>. This directory must be a standard certificate directory: that
248 is a hash of each subject name (using B<x509 -hash>) should be linked
253 digest algorithm to use when signing or resigning. If not present then the
254 default digest algorithm for the signing key will be used (usually SHA1).
256 =item B<-des -des3 -rc2-40 -rc2-64 -rc2-128 -aes128 -aes192 -aes256 -camellia128 -camellia192 -camellia256>
258 the encryption algorithm to use. DES (56 bits), triple DES (168 bits), 40, 64
259 or 128 bit RC2, 128, 192 or 256 bit AES, or 128, 192 or 256 bit Camellia
260 respectively. Any other cipher name (as recognized by the
261 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
262 example B<-aes_128_cbc>.
264 If not specified triple DES is used. Only used with B<-encrypt> and
265 B<-EncryptedData_create> commands.
269 when verifying a message normally certificates (if any) included in
270 the message are searched for the signing certificate. With this option
271 only the certificates specified in the B<-certfile> option are used.
272 The supplied certificates can still be used as untrusted CAs however.
274 =item B<-no_signer_cert_verify>
276 do not verify the signers certificate of a signed message.
280 when signing a message the signer's certificate is normally included
281 with this option it is excluded. This will reduce the size of the
282 signed message but the verifier must have a copy of the signers certificate
283 available locally (passed using the B<-certfile> option for example).
287 normally when a message is signed a set of attributes are included which
288 include the signing time and supported symmetric algorithms. With this
289 option they are not included.
293 exclude the list of supported algorithms from signed attributes, other options
294 such as signing time and content type are still included.
298 normally the input message is converted to "canonical" format which is
299 effectively using CR and LF as end of line: as required by the S/MIME
300 specification. When this option is present no translation occurs. This
301 is useful when handling binary data which may not be in MIME format.
305 when signing a message use opaque signing: this form is more resistant
306 to translation by mail relays but it cannot be read by mail agents that
307 do not support S/MIME. Without this option cleartext signing with
308 the MIME type multipart/signed is used.
310 =item B<-certfile file>
312 allows additional certificates to be specified. When signing these will
313 be included with the message. When verifying these will be searched for
314 the signers certificates. The certificates should be in PEM format.
316 =item B<-certsout file>
318 any certificates contained in the message are written to B<file>.
320 =item B<-signer file>
322 a signing certificate when signing or resigning a message, this option can be
323 used multiple times if more than one signer is required. If a message is being
324 verified then the signers certificates will be written to this file if the
325 verification was successful.
329 the recipients certificate when decrypting a message. This certificate
330 must match one of the recipients of the message or an error occurs.
334 use subject key identifier to identify certificates instead of issuer name and
335 serial number. The supplied certificate B<must> include a subject key
336 identifier extension. Supported by B<-sign> and B<-encrypt> options.
338 =item B<-receipt_request_all -receipt_request_first>
340 for B<-sign> option include a signed receipt request. Indicate requests should
341 be provided by all receipient or first tier recipients (those mailed directly
342 and not from a mailing list). Ignored it B<-receipt_request_from> is included.
344 =item B<-receipt_request_from emailaddress>
346 for B<-sign> option include a signed receipt request. Add an explicit email
347 address where receipts should be supplied.
349 =item B<-receipt_request_to emailaddress>
351 Add an explicit email address where signed receipts should be sent to. This
352 option B<must> but supplied if a signed receipt it requested.
354 =item B<-receipt_request_print>
356 For the B<-verify> operation print out the contents of any signed receipt
359 =item B<-secretkey key>
361 specify symmetric key to use. The key must be supplied in hex format and be
362 consistent with the algorithm used. Supported by the B<-EncryptedData_encrypt>
363 B<-EncrryptedData_decrypt>, B<-encrypt> and B<-decrypt> options. When used
364 with B<-encrypt> or B<-decrypt> the supplied key is used to wrap or unwrap the
365 content encryption key using an AES key in the B<KEKRecipientInfo> type.
367 =item B<-secretkeyid id>
369 the key identifier for the supplied symmetric key for B<KEKRecipientInfo> type.
370 This option B<must> be present if the B<-secretkey> option is used with
371 B<-encrypt>. With B<-decrypt> operations the B<id> is used to locate the
372 relevant key if it is not supplied then an attempt is used to decrypt any
373 B<KEKRecipientInfo> structures.
375 =item B<-econtent_type type>
377 set the encapsulated content type to B<type> if not supplied the B<Data> type
378 is used. The B<type> argument can be any valid OID name in either text or
383 the private key to use when signing or decrypting. This must match the
384 corresponding certificate. If this option is not specified then the
385 private key must be included in the certificate file specified with
386 the B<-recip> or B<-signer> file. When signing this option can be used
387 multiple times to specify successive keys.
391 the private key password source. For more information about the format of B<arg>
392 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
394 =item B<-rand file(s)>
396 a file or files containing random data used to seed the random number
397 generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
398 Multiple files can be specified separated by a OS-dependent character.
399 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
404 one or more certificates of message recipients: used when encrypting
407 =item B<-to, -from, -subject>
409 the relevant mail headers. These are included outside the signed
410 portion of a message so they may be included manually. If signing
411 then many S/MIME mail clients check the signers certificate's email
412 address matches that specified in the From: address.
418 The MIME message must be sent without any blank lines between the
419 headers and the output. Some mail programs will automatically add
420 a blank line. Piping the mail directly to sendmail is one way to
421 achieve the correct format.
423 The supplied message to be signed or encrypted must include the
424 necessary MIME headers or many S/MIME clients wont display it
425 properly (if at all). You can use the B<-text> option to automatically
426 add plain text headers.
428 A "signed and encrypted" message is one where a signed message is
429 then encrypted. This can be produced by encrypting an already signed
430 message: see the examples section.
432 This version of the program only allows one signer per message but it
433 will verify multiple signers on received messages. Some S/MIME clients
434 choke if a message contains multiple signers. It is possible to sign
435 messages "in parallel" by signing an already signed message.
437 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
438 clients. Strictly speaking these process CMS enveloped data: CMS
439 encrypted data is used for other purposes.
441 The B<-resign> option uses an existing message digest when adding a new
442 signer. This means that attributes must be present in at least one existing
443 signer using the same message digest or this operation will fail.
445 The B<-stream> and B<-indef> options enable experimental streaming I/O support.
446 As a result the encoding is BER using indefinite length constructed encoding
447 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
448 B<-sign> operation if the content is not detached.
450 Streaming is always used for the B<-sign> operation with detached data but
451 since the content is no longer part of the CMS structure the encoding
460 the operation was completely successfully.
464 an error occurred parsing the command options.
468 one of the input files could not be read.
472 an error occurred creating the CMS file or when reading the MIME
477 an error occurred decrypting or verifying the message.
481 the message was verified correctly but an error occurred writing out
482 the signers certificates.
486 =head1 COMPATIBILITY WITH PKCS#7 format.
488 The B<smime> utility can only process the older B<PKCS#7> format. The B<cms>
489 utility supports Cryptographic Message Syntax format. Use of some features
490 will result in messages which cannot be processed by applications which only
491 support the older format. These are detailed below.
493 The use of the B<-keyid> option with B<-sign> or B<-encrypt>.
495 The B<-outform PEM> option uses different headers.
497 The B<-compress> option.
499 The B<-secretkey> option when used with B<-encrypt>.
501 Additionally the B<-EncryptedData_create> and B<-data_create> type cannot
502 be processed by the older B<smime> command.
506 Create a cleartext signed message:
508 openssl cms -sign -in message.txt -text -out mail.msg \
511 Create an opaque signed message
513 openssl cms -sign -in message.txt -text -out mail.msg -nodetach \
516 Create a signed message, include some additional certificates and
517 read the private key from another file:
519 openssl cms -sign -in in.txt -text -out mail.msg \
520 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
522 Create a signed message with two signers, use key identifier:
524 openssl cms -sign -in message.txt -text -out mail.msg \
525 -signer mycert.pem -signer othercert.pem -keyid
527 Send a signed message under Unix directly to sendmail, including headers:
529 openssl cms -sign -in in.txt -text -signer mycert.pem \
530 -from steve@openssl.org -to someone@somewhere \
531 -subject "Signed message" | sendmail someone@somewhere
533 Verify a message and extract the signer's certificate if successful:
535 openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt
537 Send encrypted mail using triple DES:
539 openssl cms -encrypt -in in.txt -from steve@openssl.org \
540 -to someone@somewhere -subject "Encrypted message" \
541 -des3 user.pem -out mail.msg
543 Sign and encrypt mail:
545 openssl cms -sign -in ml.txt -signer my.pem -text \
546 | openssl cms -encrypt -out mail.msg \
547 -from steve@openssl.org -to someone@somewhere \
548 -subject "Signed and Encrypted message" -des3 user.pem
550 Note: the encryption command does not include the B<-text> option because the
551 message being encrypted already has MIME headers.
555 openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
557 The output from Netscape form signing is a PKCS#7 structure with the
558 detached signature format. You can use this program to verify the
559 signature by line wrapping the base64 encoded structure and surrounding
562 -----BEGIN PKCS7-----
565 and using the command,
567 openssl cms -verify -inform PEM -in signature.pem -content content.txt
569 alternatively you can base64 decode the signature and use
571 openssl cms -verify -inform DER -in signature.der -content content.txt
573 Create an encrypted message using 128 bit Camellia:
575 openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
577 Add a signer to an existing message:
579 openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg
583 The MIME parser isn't very clever: it seems to handle most messages that I've
584 thrown at it but it may choke on others.
586 The code currently will only write out the signer's certificate to a file: if
587 the signer has a separate encryption certificate this must be manually
588 extracted. There should be some heuristic that determines the correct
589 encryption certificate.
591 Ideally a database should be maintained of a certificates for each email
594 The code doesn't currently take note of the permitted symmetric encryption
595 algorithms as supplied in the SMIMECapabilities signed attribute. this means the
596 user has to manually include the correct encryption algorithm. It should store
597 the list of permitted ciphers in a database and only use those.
599 No revocation checking is done on the signer's certificate.
603 The use of multiple B<-signer> options and the B<-resign> command were first
604 added in OpenSSL 0.9.9