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7122aafc DSH |
1 | =pod |
2 | ||
3 | =head1 NAME | |
4 | ||
5 | cms - CMS utility | |
6 | ||
7 | =head1 SYNOPSIS | |
8 | ||
9 | B<openssl> B<cms> | |
10 | [B<-encrypt>] | |
11 | [B<-decrypt>] | |
12 | [B<-sign>] | |
7122aafc DSH |
13 | [B<-verify>] |
14 | [B<-cmsout>] | |
41f81a01 DSH |
15 | [B<-resign>] |
16 | [B<-data_create>] | |
17 | [B<-data_out>] | |
18 | [B<-digest_create>] | |
19 | [B<-digest_verify>] | |
20 | [B<-compress>] | |
21 | [B<-uncompress>] | |
22 | [B<-EncryptedData_encrypt>] | |
23 | [B<-sign_receipt>] | |
24 | [B<-verify_receipt receipt>] | |
25 | [B<-in filename>] | |
26 | [B<-inform SMIME|PEM|DER>] | |
27 | [B<-rctform SMIME|PEM|DER>] | |
28 | [B<-out filename>] | |
29 | [B<-outform SMIME|PEM|DER>] | |
30 | [B<-stream -indef -noindef>] | |
31 | [B<-noindef>] | |
32 | [B<-content filename>] | |
33 | [B<-text>] | |
34 | [B<-noout>] | |
35 | [B<-print>] | |
36 | [B<-CAfile file>] | |
37 | [B<-CApath dir>] | |
38 | [B<-md digest>] | |
e5fa864f | 39 | [B<-[cipher]>] |
41f81a01 DSH |
40 | [B<-nointern>] |
41 | [B<-no_signer_cert_verify>] | |
42 | [B<-nocerts>] | |
43 | [B<-noattr>] | |
44 | [B<-nosmimecap>] | |
45 | [B<-binary>] | |
46 | [B<-nodetach>] | |
7122aafc | 47 | [B<-certfile file>] |
4a954b56 | 48 | [B<-certsout file>] |
7122aafc | 49 | [B<-signer file>] |
41f81a01 DSH |
50 | [B<-recip file>] |
51 | [B<-keyid>] | |
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>] | |
56 | [B<-secretkey key>] | |
57 | [B<-secretkeyid id>] | |
58 | [B<-econtent_type type>] | |
7122aafc | 59 | [B<-inkey file>] |
41f81a01 | 60 | [B<-passin arg>] |
7122aafc | 61 | [B<-rand file(s)>] |
41f81a01 DSH |
62 | [B<cert.pem...>] |
63 | [B<-to addr>] | |
64 | [B<-from addr>] | |
65 | [B<-subject subj>] | |
7122aafc DSH |
66 | [cert.pem]... |
67 | ||
68 | =head1 DESCRIPTION | |
69 | ||
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. | |
72 | ||
73 | =head1 COMMAND OPTIONS | |
74 | ||
41f81a01 DSH |
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 | |
7122aafc DSH |
77 | type. |
78 | ||
79 | =over 4 | |
80 | ||
81 | =item B<-encrypt> | |
82 | ||
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>. | |
86 | ||
87 | =item B<-decrypt> | |
88 | ||
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. | |
92 | ||
93 | =item B<-sign> | |
94 | ||
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 | |
97 | to the output file. | |
98 | ||
99 | =item B<-verify> | |
100 | ||
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. | |
103 | ||
104 | =item B<-cmsout> | |
105 | ||
106 | takes an input message and writes out a PEM encoded CMS structure. | |
107 | ||
108 | =item B<-resign> | |
109 | ||
110 | resign a message: take an existing message and one or more new signers. | |
111 | ||
112 | =item B<-data_create> | |
113 | ||
114 | Create a CMS B<Data> type. | |
115 | ||
116 | =item B<-data_out> | |
117 | ||
118 | B<Data> type and output the content. | |
119 | ||
120 | =item B<-digest_create> | |
121 | ||
122 | Create a CMS B<DigestedData> type. | |
123 | ||
124 | =item B<-digest_verify> | |
125 | ||
126 | Verify a CMS B<DigestedData> type and output the content. | |
127 | ||
128 | =item B<-compress> | |
129 | ||
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. | |
132 | ||
133 | =item B<-uncompress> | |
134 | ||
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 | |
137 | output an error. | |
138 | ||
139 | =item B<-EncryptedData_encrypt> | |
140 | ||
141 | Encrypt suppled content using supplied symmetric key and algorithm using a CMS | |
142 | B<EncrytedData> type and output the content. | |
143 | ||
41f81a01 DSH |
144 | =item B<-sign_receipt> |
145 | ||
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. | |
149 | ||
150 | =item B<-verify_receipt receipt> | |
151 | ||
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. | |
155 | ||
7122aafc DSH |
156 | =item B<-in filename> |
157 | ||
41f81a01 DSH |
158 | the input message to be encrypted or signed or the message to be decrypted |
159 | or verified. | |
7122aafc DSH |
160 | |
161 | =item B<-inform SMIME|PEM|DER> | |
162 | ||
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. | |
169 | ||
41f81a01 DSH |
170 | =item B<-rctform SMIME|PEM|DER> |
171 | ||
172 | specify the format for a signed receipt for use with the B<-receipt_verify> | |
173 | operation. | |
174 | ||
7122aafc DSH |
175 | =item B<-out filename> |
176 | ||
177 | the message text that has been decrypted or verified or the output MIME | |
178 | format message that has been signed or verified. | |
179 | ||
180 | =item B<-outform SMIME|PEM|DER> | |
181 | ||
182 | this specifies the output format for the CMS structure. The default | |
41f81a01 | 183 | is B<SMIME> which writes an S/MIME format message. B<PEM> and B<DER> |
7122aafc DSH |
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. | |
188 | ||
189 | =item B<-stream -indef -noindef> | |
190 | ||
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 | |
196 | other operations. | |
197 | ||
198 | =item B<-noindef> | |
199 | ||
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. | |
203 | ||
204 | =item B<-content filename> | |
205 | ||
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. | |
211 | ||
212 | =item B<-text> | |
213 | ||
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. | |
218 | ||
41f81a01 DSH |
219 | =item B<-noout> |
220 | ||
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. | |
224 | ||
225 | =item B<-print> | |
226 | ||
227 | for the B<-cmsout> operation print out all fields of the CMS structure. This | |
228 | is mainly useful for testing purposes. | |
229 | ||
7122aafc DSH |
230 | =item B<-CAfile file> |
231 | ||
232 | a file containing trusted CA certificates, only used with B<-verify>. | |
233 | ||
234 | =item B<-CApath dir> | |
235 | ||
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 | |
239 | to each certificate. | |
240 | ||
241 | =item B<-md digest> | |
242 | ||
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). | |
245 | ||
e5fa864f | 246 | =item B<-[cipher]> |
7122aafc | 247 | |
e5fa864f DSH |
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 | |
7122aafc | 250 | EVP_get_cipherbyname() function) can also be used preceded by a dash, for |
e5fa864f DSH |
251 | example B<-aes_128_cbc>. See L<B<enc>|enc(1)> for a list of ciphers |
252 | supported by your version of OpenSSL. | |
7122aafc DSH |
253 | |
254 | If not specified triple DES is used. Only used with B<-encrypt> and | |
255 | B<-EncryptedData_create> commands. | |
256 | ||
257 | =item B<-nointern> | |
258 | ||
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. | |
263 | ||
41f81a01 | 264 | =item B<-no_signer_cert_verify> |
7122aafc DSH |
265 | |
266 | do not verify the signers certificate of a signed message. | |
267 | ||
268 | =item B<-nocerts> | |
269 | ||
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). | |
274 | ||
275 | =item B<-noattr> | |
276 | ||
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. | |
280 | ||
281 | =item B<-nosmimecap> | |
282 | ||
283 | exclude the list of supported algorithms from signed attributes, other options | |
284 | such as signing time and content type are still included. | |
285 | ||
286 | =item B<-binary> | |
287 | ||
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. | |
292 | ||
293 | =item B<-nodetach> | |
294 | ||
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. | |
299 | ||
300 | =item B<-certfile file> | |
301 | ||
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. | |
305 | ||
4a954b56 DSH |
306 | =item B<-certsout file> |
307 | ||
c386f8ac | 308 | any certificates contained in the message are written to B<file>. |
4a954b56 | 309 | |
7122aafc DSH |
310 | =item B<-signer file> |
311 | ||
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. | |
316 | ||
317 | =item B<-recip file> | |
318 | ||
319 | the recipients certificate when decrypting a message. This certificate | |
320 | must match one of the recipients of the message or an error occurs. | |
321 | ||
322 | =item B<-keyid> | |
323 | ||
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. | |
327 | ||
41f81a01 DSH |
328 | =item B<-receipt_request_all -receipt_request_first> |
329 | ||
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. | |
333 | ||
334 | =item B<-receipt_request_from emailaddress> | |
335 | ||
336 | for B<-sign> option include a signed receipt request. Add an explicit email | |
337 | address where receipts should be supplied. | |
338 | ||
339 | =item B<-receipt_request_to emailaddress> | |
340 | ||
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. | |
343 | ||
344 | =item B<-receipt_request_print> | |
345 | ||
346 | For the B<-verify> operation print out the contents of any signed receipt | |
347 | requests. | |
348 | ||
7122aafc DSH |
349 | =item B<-secretkey key> |
350 | ||
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. | |
356 | ||
357 | =item B<-secretkeyid id> | |
358 | ||
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. | |
364 | ||
365 | =item B<-econtent_type type> | |
366 | ||
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 | |
369 | numerical format. | |
370 | ||
371 | =item B<-inkey file> | |
372 | ||
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. | |
378 | ||
379 | =item B<-passin arg> | |
380 | ||
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)>. | |
383 | ||
384 | =item B<-rand file(s)> | |
385 | ||
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 | |
390 | all others. | |
391 | ||
392 | =item B<cert.pem...> | |
393 | ||
394 | one or more certificates of message recipients: used when encrypting | |
395 | a message. | |
396 | ||
397 | =item B<-to, -from, -subject> | |
398 | ||
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. | |
403 | ||
e5fa864f DSH |
404 | =item B<-purpose, -ignore_critical, -issuer_checks, -crl_check, -crl_check_all, -policy_check, -extended_crl, -x509_strict, -policy> |
405 | ||
406 | Set various certificate chain valiadition option. See the | |
407 | L<B<verify>|verify(1)> manual page for details. | |
408 | ||
7122aafc DSH |
409 | =back |
410 | ||
411 | =head1 NOTES | |
412 | ||
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. | |
417 | ||
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. | |
422 | ||
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. | |
426 | ||
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. | |
431 | ||
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. | |
435 | ||
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. | |
439 | ||
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. | |
444 | ||
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 | |
447 | remains DER. | |
448 | ||
449 | =head1 EXIT CODES | |
450 | ||
451 | =over 4 | |
452 | ||
453 | =item 0 | |
454 | ||
455 | the operation was completely successfully. | |
456 | ||
457 | =item 1 | |
458 | ||
459 | an error occurred parsing the command options. | |
460 | ||
461 | =item 2 | |
462 | ||
463 | one of the input files could not be read. | |
464 | ||
465 | =item 3 | |
466 | ||
467 | an error occurred creating the CMS file or when reading the MIME | |
468 | message. | |
469 | ||
470 | =item 4 | |
471 | ||
472 | an error occurred decrypting or verifying the message. | |
473 | ||
474 | =item 5 | |
475 | ||
476 | the message was verified correctly but an error occurred writing out | |
477 | the signers certificates. | |
478 | ||
479 | =back | |
480 | ||
481 | =head1 COMPATIBILITY WITH PKCS#7 format. | |
482 | ||
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. | |
487 | ||
488 | The use of the B<-keyid> option with B<-sign> or B<-encrypt>. | |
489 | ||
490 | The B<-outform PEM> option uses different headers. | |
491 | ||
492 | The B<-compress> option. | |
493 | ||
494 | The B<-secretkey> option when used with B<-encrypt>. | |
495 | ||
496 | Additionally the B<-EncryptedData_create> and B<-data_create> type cannot | |
497 | be processed by the older B<smime> command. | |
498 | ||
499 | =head1 EXAMPLES | |
500 | ||
501 | Create a cleartext signed message: | |
502 | ||
503 | openssl cms -sign -in message.txt -text -out mail.msg \ | |
504 | -signer mycert.pem | |
505 | ||
506 | Create an opaque signed message | |
507 | ||
508 | openssl cms -sign -in message.txt -text -out mail.msg -nodetach \ | |
509 | -signer mycert.pem | |
510 | ||
511 | Create a signed message, include some additional certificates and | |
512 | read the private key from another file: | |
513 | ||
514 | openssl cms -sign -in in.txt -text -out mail.msg \ | |
515 | -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem | |
516 | ||
517 | Create a signed message with two signers, use key identifier: | |
518 | ||
519 | openssl cms -sign -in message.txt -text -out mail.msg \ | |
520 | -signer mycert.pem -signer othercert.pem -keyid | |
521 | ||
522 | Send a signed message under Unix directly to sendmail, including headers: | |
523 | ||
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 | |
527 | ||
528 | Verify a message and extract the signer's certificate if successful: | |
529 | ||
530 | openssl cms -verify -in mail.msg -signer user.pem -out signedtext.txt | |
531 | ||
532 | Send encrypted mail using triple DES: | |
533 | ||
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 | |
537 | ||
538 | Sign and encrypt mail: | |
539 | ||
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 | |
544 | ||
545 | Note: the encryption command does not include the B<-text> option because the | |
546 | message being encrypted already has MIME headers. | |
547 | ||
548 | Decrypt mail: | |
549 | ||
550 | openssl cms -decrypt -in mail.msg -recip mycert.pem -inkey key.pem | |
551 | ||
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 | |
555 | it with: | |
556 | ||
557 | -----BEGIN PKCS7----- | |
558 | -----END PKCS7----- | |
559 | ||
560 | and using the command, | |
561 | ||
562 | openssl cms -verify -inform PEM -in signature.pem -content content.txt | |
563 | ||
564 | alternatively you can base64 decode the signature and use | |
565 | ||
566 | openssl cms -verify -inform DER -in signature.der -content content.txt | |
567 | ||
568 | Create an encrypted message using 128 bit Camellia: | |
569 | ||
570 | openssl cms -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem | |
571 | ||
572 | Add a signer to an existing message: | |
573 | ||
574 | openssl cms -resign -in mail.msg -signer newsign.pem -out mail2.msg | |
575 | ||
576 | =head1 BUGS | |
577 | ||
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. | |
580 | ||
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. | |
585 | ||
586 | Ideally a database should be maintained of a certificates for each email | |
587 | address. | |
588 | ||
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. | |
593 | ||
594 | No revocation checking is done on the signer's certificate. | |
595 | ||
596 | =head1 HISTORY | |
597 | ||
598 | The use of multiple B<-signer> options and the B<-resign> command were first | |
599 | added in OpenSSL 0.9.9 | |
600 | ||
601 | ||
602 | =cut |