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