25 [B<-attime timestamp>]
46 [B<-verify_depth num>]
47 [B<-verify_email email>]
48 [B<-verify_hostname hostname>]
50 [B<-verify_name name>]
55 [B<-inform SMIME|PEM|DER>]
59 [B<-outform SMIME|PEM|DER>]
74 The B<smime> command handles S/MIME mail. It can encrypt, decrypt, sign and
75 verify S/MIME messages.
77 =head1 COMMAND OPTIONS
79 There are six operation options that set the type of operation to be performed.
80 The meaning of the other options varies according to the operation type.
86 Print out a usage message.
90 encrypt mail for the given recipient certificates. Input file is the message
91 to be encrypted. The output file is the encrypted mail in MIME format.
95 decrypt mail using the supplied certificate and private key. Expects an
96 encrypted mail message in MIME format for the input file. The decrypted mail
97 is written to the output file.
101 sign mail using the supplied certificate and private key. Input file is
102 the message to be signed. The signed message in MIME format is written
107 verify signed mail. Expects a signed mail message on input and outputs
108 the signed data. Both clear text and opaque signing is supported.
112 takes an input message and writes out a PEM encoded PKCS#7 structure.
116 resign a message: take an existing message and one or more new signers.
118 =item B<-in filename>
120 the input message to be encrypted or signed or the MIME message to
121 be decrypted or verified.
123 =item B<-inform SMIME|PEM|DER>
125 this specifies the input format for the PKCS#7 structure. The default
126 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
127 format change this to expect PEM and DER format PKCS#7 structures
128 instead. This currently only affects the input format of the PKCS#7
129 structure, if no PKCS#7 structure is being input (for example with
130 B<-encrypt> or B<-sign>) this option has no effect.
132 =item B<-out filename>
134 the message text that has been decrypted or verified or the output MIME
135 format message that has been signed or verified.
137 =item B<-outform SMIME|PEM|DER>
139 this specifies the output format for the PKCS#7 structure. The default
140 is B<SMIME> which write an S/MIME format message. B<PEM> and B<DER>
141 format change this to write PEM and DER format PKCS#7 structures
142 instead. This currently only affects the output format of the PKCS#7
143 structure, if no PKCS#7 structure is being output (for example with
144 B<-verify> or B<-decrypt>) this option has no effect.
146 =item B<-stream -indef -noindef>
148 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
149 for encoding operations. This permits single pass processing of data without
150 the need to hold the entire contents in memory, potentially supporting very
151 large files. Streaming is automatically set for S/MIME signing with detached
152 data if the output format is B<SMIME> it is currently off by default for all
157 disable streaming I/O where it would produce and indefinite length constructed
158 encoding. This option currently has no effect. In future streaming will be
159 enabled by default on all relevant operations and this option will disable it.
161 =item B<-content filename>
163 This specifies a file containing the detached content, this is only
164 useful with the B<-verify> command. This is only usable if the PKCS#7
165 structure is using the detached signature form where the content is
166 not included. This option will override any content if the input format
167 is S/MIME and it uses the multipart/signed MIME content type.
171 this option adds plain text (text/plain) MIME headers to the supplied
172 message if encrypting or signing. If decrypting or verifying it strips
173 off text headers: if the decrypted or verified message is not of MIME
174 type text/plain then an error occurs.
176 =item B<-CAfile file>
178 a file containing trusted CA certificates, only used with B<-verify>.
182 a directory containing trusted CA certificates, only used with
183 B<-verify>. This directory must be a standard certificate directory: that
184 is a hash of each subject name (using B<x509 -hash>) should be linked
189 Do not load the trusted CA certificates from the default file location
193 Do not load the trusted CA certificates from the default directory location
197 digest algorithm to use when signing or resigning. If not present then the
198 default digest algorithm for the signing key will be used (usually SHA1).
202 the encryption algorithm to use. For example DES (56 bits) - B<-des>,
203 triple DES (168 bits) - B<-des3>,
204 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
205 example B<-aes-128-cbc>. See L<B<enc>|enc(1)> for list of ciphers
206 supported by your version of OpenSSL.
208 If not specified triple DES is used. Only used with B<-encrypt>.
212 when verifying a message normally certificates (if any) included in
213 the message are searched for the signing certificate. With this option
214 only the certificates specified in the B<-certfile> option are used.
215 The supplied certificates can still be used as untrusted CAs however.
219 do not verify the signers certificate of a signed message.
223 do not do chain verification of signers certificates: that is don't
224 use the certificates in the signed message as untrusted CAs.
228 don't try to verify the signatures on the message.
232 when signing a message the signer's certificate is normally included
233 with this option it is excluded. This will reduce the size of the
234 signed message but the verifier must have a copy of the signers certificate
235 available locally (passed using the B<-certfile> option for example).
239 normally when a message is signed a set of attributes are included which
240 include the signing time and supported symmetric algorithms. With this
241 option they are not included.
245 normally the input message is converted to "canonical" format which is
246 effectively using CR and LF as end of line: as required by the S/MIME
247 specification. When this option is present no translation occurs. This
248 is useful when handling binary data which may not be in MIME format.
252 normally the output file uses a single B<LF> as end of line. When this
253 option is present B<CRLF> is used instead.
257 when signing a message use opaque signing: this form is more resistant
258 to translation by mail relays but it cannot be read by mail agents that
259 do not support S/MIME. Without this option cleartext signing with
260 the MIME type multipart/signed is used.
262 =item B<-certfile file>
264 allows additional certificates to be specified. When signing these will
265 be included with the message. When verifying these will be searched for
266 the signers certificates. The certificates should be in PEM format.
268 =item B<-signer file>
270 a signing certificate when signing or resigning a message, this option can be
271 used multiple times if more than one signer is required. If a message is being
272 verified then the signers certificates will be written to this file if the
273 verification was successful.
277 the recipients certificate when decrypting a message. This certificate
278 must match one of the recipients of the message or an error occurs.
282 the private key to use when signing or decrypting. This must match the
283 corresponding certificate. If this option is not specified then the
284 private key must be included in the certificate file specified with
285 the B<-recip> or B<-signer> file. When signing this option can be used
286 multiple times to specify successive keys.
290 the private key password source. For more information about the format of B<arg>
291 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
293 =item B<-rand file(s)>
295 a file or files containing random data used to seed the random number
296 generator, or an EGD socket (see L<RAND_egd(3)>).
297 Multiple files can be specified separated by an OS-dependent character.
298 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
303 one or more certificates of message recipients: used when encrypting
306 =item B<-to, -from, -subject>
308 the relevant mail headers. These are included outside the signed
309 portion of a message so they may be included manually. If signing
310 then many S/MIME mail clients check the signers certificate's email
311 address matches that specified in the From: address.
313 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
314 B<-explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
315 B<-inhibit_map>, B<-no_alt_chains>, B<-partial_chain>, B<-policy>,
316 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
317 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
318 B<-auth_level>, B<-verify_depth>, B<-verify_email>, B<-verify_hostname>,
319 B<-verify_ip>, B<-verify_name>, B<-x509_strict>
321 Set various options of certificate chain verification. See
322 L<verify(1)> manual page for details.
328 The MIME message must be sent without any blank lines between the
329 headers and the output. Some mail programs will automatically add
330 a blank line. Piping the mail directly to sendmail is one way to
331 achieve the correct format.
333 The supplied message to be signed or encrypted must include the
334 necessary MIME headers or many S/MIME clients wont display it
335 properly (if at all). You can use the B<-text> option to automatically
336 add plain text headers.
338 A "signed and encrypted" message is one where a signed message is
339 then encrypted. This can be produced by encrypting an already signed
340 message: see the examples section.
342 This version of the program only allows one signer per message but it
343 will verify multiple signers on received messages. Some S/MIME clients
344 choke if a message contains multiple signers. It is possible to sign
345 messages "in parallel" by signing an already signed message.
347 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
348 clients. Strictly speaking these process PKCS#7 enveloped data: PKCS#7
349 encrypted data is used for other purposes.
351 The B<-resign> option uses an existing message digest when adding a new
352 signer. This means that attributes must be present in at least one existing
353 signer using the same message digest or this operation will fail.
355 The B<-stream> and B<-indef> options enable streaming I/O support.
356 As a result the encoding is BER using indefinite length constructed encoding
357 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
358 B<-sign> operation if the content is not detached.
360 Streaming is always used for the B<-sign> operation with detached data but
361 since the content is no longer part of the PKCS#7 structure the encoding
370 the operation was completely successfully.
374 an error occurred parsing the command options.
378 one of the input files could not be read.
382 an error occurred creating the PKCS#7 file or when reading the MIME
387 an error occurred decrypting or verifying the message.
391 the message was verified correctly but an error occurred writing out
392 the signers certificates.
398 Create a cleartext signed message:
400 openssl smime -sign -in message.txt -text -out mail.msg \
403 Create an opaque signed message:
405 openssl smime -sign -in message.txt -text -out mail.msg -nodetach \
408 Create a signed message, include some additional certificates and
409 read the private key from another file:
411 openssl smime -sign -in in.txt -text -out mail.msg \
412 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
414 Create a signed message with two signers:
416 openssl smime -sign -in message.txt -text -out mail.msg \
417 -signer mycert.pem -signer othercert.pem
419 Send a signed message under Unix directly to sendmail, including headers:
421 openssl smime -sign -in in.txt -text -signer mycert.pem \
422 -from steve@openssl.org -to someone@somewhere \
423 -subject "Signed message" | sendmail someone@somewhere
425 Verify a message and extract the signer's certificate if successful:
427 openssl smime -verify -in mail.msg -signer user.pem -out signedtext.txt
429 Send encrypted mail using triple DES:
431 openssl smime -encrypt -in in.txt -from steve@openssl.org \
432 -to someone@somewhere -subject "Encrypted message" \
433 -des3 user.pem -out mail.msg
435 Sign and encrypt mail:
437 openssl smime -sign -in ml.txt -signer my.pem -text \
438 | openssl smime -encrypt -out mail.msg \
439 -from steve@openssl.org -to someone@somewhere \
440 -subject "Signed and Encrypted message" -des3 user.pem
442 Note: the encryption command does not include the B<-text> option because the
443 message being encrypted already has MIME headers.
447 openssl smime -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
449 The output from Netscape form signing is a PKCS#7 structure with the
450 detached signature format. You can use this program to verify the
451 signature by line wrapping the base64 encoded structure and surrounding
454 -----BEGIN PKCS7-----
457 and using the command:
459 openssl smime -verify -inform PEM -in signature.pem -content content.txt
461 Alternatively you can base64 decode the signature and use:
463 openssl smime -verify -inform DER -in signature.der -content content.txt
465 Create an encrypted message using 128 bit Camellia:
467 openssl smime -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
469 Add a signer to an existing message:
471 openssl smime -resign -in mail.msg -signer newsign.pem -out mail2.msg
475 The MIME parser isn't very clever: it seems to handle most messages that I've
476 thrown at it but it may choke on others.
478 The code currently will only write out the signer's certificate to a file: if
479 the signer has a separate encryption certificate this must be manually
480 extracted. There should be some heuristic that determines the correct
481 encryption certificate.
483 Ideally a database should be maintained of a certificates for each email
486 The code doesn't currently take note of the permitted symmetric encryption
487 algorithms as supplied in the SMIMECapabilities signed attribute. This means the
488 user has to manually include the correct encryption algorithm. It should store
489 the list of permitted ciphers in a database and only use those.
491 No revocation checking is done on the signer's certificate.
493 The current code can only handle S/MIME v2 messages, the more complex S/MIME v3
494 structures may cause parsing errors.
498 The use of multiple B<-signer> options and the B<-resign> command were first
499 added in OpenSSL 1.0.0
501 The -no_alt_chains options was first added to OpenSSL 1.1.0.
507 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
509 Licensed under the OpenSSL license (the "License"). You may not use
510 this file except in compliance with the License. You can obtain a copy
511 in the file LICENSE in the source distribution or at
512 L<https://www.openssl.org/source/license.html>.