20 [B<-attime timestamp>]
40 [B<-verify_depth num>]
41 [B<-verify_email email>]
42 [B<-verify_hostname hostname>]
44 [B<-verify_name name>]
49 [B<-inform SMIME|PEM|DER>]
53 [B<-outform SMIME|PEM|DER>]
68 The B<smime> command handles S/MIME mail. It can encrypt, decrypt, sign and
69 verify S/MIME messages.
71 =head1 COMMAND OPTIONS
73 There are six operation options that set the type of operation to be performed.
74 The meaning of the other options varies according to the operation type.
80 encrypt mail for the given recipient certificates. Input file is the message
81 to be encrypted. The output file is the encrypted mail in MIME format.
85 decrypt mail using the supplied certificate and private key. Expects an
86 encrypted mail message in MIME format for the input file. The decrypted mail
87 is written to the output file.
91 sign mail using the supplied certificate and private key. Input file is
92 the message to be signed. The signed message in MIME format is written
97 verify signed mail. Expects a signed mail message on input and outputs
98 the signed data. Both clear text and opaque signing is supported.
102 takes an input message and writes out a PEM encoded PKCS#7 structure.
106 resign a message: take an existing message and one or more new signers.
108 =item B<-in filename>
110 the input message to be encrypted or signed or the MIME message to
111 be decrypted or verified.
113 =item B<-inform SMIME|PEM|DER>
115 this specifies the input format for the PKCS#7 structure. The default
116 is B<SMIME> which reads an S/MIME format message. B<PEM> and B<DER>
117 format change this to expect PEM and DER format PKCS#7 structures
118 instead. This currently only affects the input format of the PKCS#7
119 structure, if no PKCS#7 structure is being input (for example with
120 B<-encrypt> or B<-sign>) this option has no effect.
122 =item B<-out filename>
124 the message text that has been decrypted or verified or the output MIME
125 format message that has been signed or verified.
127 =item B<-outform SMIME|PEM|DER>
129 this specifies the output format for the PKCS#7 structure. The default
130 is B<SMIME> which write an S/MIME format message. B<PEM> and B<DER>
131 format change this to write PEM and DER format PKCS#7 structures
132 instead. This currently only affects the output format of the PKCS#7
133 structure, if no PKCS#7 structure is being output (for example with
134 B<-verify> or B<-decrypt>) this option has no effect.
136 =item B<-stream -indef -noindef>
138 the B<-stream> and B<-indef> options are equivalent and enable streaming I/O
139 for encoding operations. This permits single pass processing of data without
140 the need to hold the entire contents in memory, potentially supporting very
141 large files. Streaming is automatically set for S/MIME signing with detached
142 data if the output format is B<SMIME> it is currently off by default for all
147 disable streaming I/O where it would produce and indefinite length constructed
148 encoding. This option currently has no effect. In future streaming will be
149 enabled by default on all relevant operations and this option will disable it.
151 =item B<-content filename>
153 This specifies a file containing the detached content, this is only
154 useful with the B<-verify> command. This is only usable if the PKCS#7
155 structure is using the detached signature form where the content is
156 not included. This option will override any content if the input format
157 is S/MIME and it uses the multipart/signed MIME content type.
161 this option adds plain text (text/plain) MIME headers to the supplied
162 message if encrypting or signing. If decrypting or verifying it strips
163 off text headers: if the decrypted or verified message is not of MIME
164 type text/plain then an error occurs.
166 =item B<-CAfile file>
168 a file containing trusted CA certificates, only used with B<-verify>.
172 a directory containing trusted CA certificates, only used with
173 B<-verify>. This directory must be a standard certificate directory: that
174 is a hash of each subject name (using B<x509 -hash>) should be linked
179 digest algorithm to use when signing or resigning. If not present then the
180 default digest algorithm for the signing key will be used (usually SHA1).
184 the encryption algorithm to use. For example DES (56 bits) - B<-des>,
185 triple DES (168 bits) - B<-des3>,
186 EVP_get_cipherbyname() function) can also be used preceded by a dash, for
187 example B<-aes_128_cbc>. See L<B<enc>|enc(1)> for list of ciphers
188 supported by your version of OpenSSL.
190 If not specified triple DES is used. Only used with B<-encrypt>.
194 when verifying a message normally certificates (if any) included in
195 the message are searched for the signing certificate. With this option
196 only the certificates specified in the B<-certfile> option are used.
197 The supplied certificates can still be used as untrusted CAs however.
201 do not verify the signers certificate of a signed message.
205 do not do chain verification of signers certificates: that is don't
206 use the certificates in the signed message as untrusted CAs.
210 don't try to verify the signatures on the message.
214 when signing a message the signer's certificate is normally included
215 with this option it is excluded. This will reduce the size of the
216 signed message but the verifier must have a copy of the signers certificate
217 available locally (passed using the B<-certfile> option for example).
221 normally when a message is signed a set of attributes are included which
222 include the signing time and supported symmetric algorithms. With this
223 option they are not included.
227 normally the input message is converted to "canonical" format which is
228 effectively using CR and LF as end of line: as required by the S/MIME
229 specification. When this option is present no translation occurs. This
230 is useful when handling binary data which may not be in MIME format.
234 when signing a message use opaque signing: this form is more resistant
235 to translation by mail relays but it cannot be read by mail agents that
236 do not support S/MIME. Without this option cleartext signing with
237 the MIME type multipart/signed is used.
239 =item B<-certfile file>
241 allows additional certificates to be specified. When signing these will
242 be included with the message. When verifying these will be searched for
243 the signers certificates. The certificates should be in PEM format.
245 =item B<-signer file>
247 a signing certificate when signing or resigning a message, this option can be
248 used multiple times if more than one signer is required. If a message is being
249 verified then the signers certificates will be written to this file if the
250 verification was successful.
254 the recipients certificate when decrypting a message. This certificate
255 must match one of the recipients of the message or an error occurs.
259 the private key to use when signing or decrypting. This must match the
260 corresponding certificate. If this option is not specified then the
261 private key must be included in the certificate file specified with
262 the B<-recip> or B<-signer> file. When signing this option can be used
263 multiple times to specify successive keys.
267 the private key password source. For more information about the format of B<arg>
268 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
270 =item B<-rand file(s)>
272 a file or files containing random data used to seed the random number
273 generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
274 Multiple files can be specified separated by a OS-dependent character.
275 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
280 one or more certificates of message recipients: used when encrypting
283 =item B<-to, -from, -subject>
285 the relevant mail headers. These are included outside the signed
286 portion of a message so they may be included manually. If signing
287 then many S/MIME mail clients check the signers certificate's email
288 address matches that specified in the From: address.
290 =item B<-attime>, B<-check_ss_sig>, B<-crl_check>, B<-crl_check_all>,
291 B<explicit_policy>, B<-extended_crl>, B<-ignore_critical>, B<-inhibit_any>,
292 B<-inhibit_map>, B<-issuer_checks>, B<-partial_chain>, B<-policy>,
293 B<-policy_check>, B<-policy_print>, B<-purpose>, B<-suiteB_128>,
294 B<-suiteB_128_only>, B<-suiteB_192>, B<-trusted_first>, B<-use_deltas>,
295 B<-verify_depth>, B<-verify_email>, B<-verify_hostname>, B<-verify_ip>,
296 B<-verify_name>, B<-x509_strict>
298 Set various options of certificate chain verification. See
299 L<B<verify>|verify(1)> manual page for details.
305 The MIME message must be sent without any blank lines between the
306 headers and the output. Some mail programs will automatically add
307 a blank line. Piping the mail directly to sendmail is one way to
308 achieve the correct format.
310 The supplied message to be signed or encrypted must include the
311 necessary MIME headers or many S/MIME clients wont display it
312 properly (if at all). You can use the B<-text> option to automatically
313 add plain text headers.
315 A "signed and encrypted" message is one where a signed message is
316 then encrypted. This can be produced by encrypting an already signed
317 message: see the examples section.
319 This version of the program only allows one signer per message but it
320 will verify multiple signers on received messages. Some S/MIME clients
321 choke if a message contains multiple signers. It is possible to sign
322 messages "in parallel" by signing an already signed message.
324 The options B<-encrypt> and B<-decrypt> reflect common usage in S/MIME
325 clients. Strictly speaking these process PKCS#7 enveloped data: PKCS#7
326 encrypted data is used for other purposes.
328 The B<-resign> option uses an existing message digest when adding a new
329 signer. This means that attributes must be present in at least one existing
330 signer using the same message digest or this operation will fail.
332 The B<-stream> and B<-indef> options enable experimental streaming I/O support.
333 As a result the encoding is BER using indefinite length constructed encoding
334 and no longer DER. Streaming is supported for the B<-encrypt> operation and the
335 B<-sign> operation if the content is not detached.
337 Streaming is always used for the B<-sign> operation with detached data but
338 since the content is no longer part of the PKCS#7 structure the encoding
347 the operation was completely successfully.
351 an error occurred parsing the command options.
355 one of the input files could not be read.
359 an error occurred creating the PKCS#7 file or when reading the MIME
364 an error occurred decrypting or verifying the message.
368 the message was verified correctly but an error occurred writing out
369 the signers certificates.
375 Create a cleartext signed message:
377 openssl smime -sign -in message.txt -text -out mail.msg \
380 Create an opaque signed message:
382 openssl smime -sign -in message.txt -text -out mail.msg -nodetach \
385 Create a signed message, include some additional certificates and
386 read the private key from another file:
388 openssl smime -sign -in in.txt -text -out mail.msg \
389 -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
391 Create a signed message with two signers:
393 openssl smime -sign -in message.txt -text -out mail.msg \
394 -signer mycert.pem -signer othercert.pem
396 Send a signed message under Unix directly to sendmail, including headers:
398 openssl smime -sign -in in.txt -text -signer mycert.pem \
399 -from steve@openssl.org -to someone@somewhere \
400 -subject "Signed message" | sendmail someone@somewhere
402 Verify a message and extract the signer's certificate if successful:
404 openssl smime -verify -in mail.msg -signer user.pem -out signedtext.txt
406 Send encrypted mail using triple DES:
408 openssl smime -encrypt -in in.txt -from steve@openssl.org \
409 -to someone@somewhere -subject "Encrypted message" \
410 -des3 user.pem -out mail.msg
412 Sign and encrypt mail:
414 openssl smime -sign -in ml.txt -signer my.pem -text \
415 | openssl smime -encrypt -out mail.msg \
416 -from steve@openssl.org -to someone@somewhere \
417 -subject "Signed and Encrypted message" -des3 user.pem
419 Note: the encryption command does not include the B<-text> option because the
420 message being encrypted already has MIME headers.
424 openssl smime -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
426 The output from Netscape form signing is a PKCS#7 structure with the
427 detached signature format. You can use this program to verify the
428 signature by line wrapping the base64 encoded structure and surrounding
431 -----BEGIN PKCS7-----
434 and using the command:
436 openssl smime -verify -inform PEM -in signature.pem -content content.txt
438 Alternatively you can base64 decode the signature and use:
440 openssl smime -verify -inform DER -in signature.der -content content.txt
442 Create an encrypted message using 128 bit Camellia:
444 openssl smime -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
446 Add a signer to an existing message:
448 openssl smime -resign -in mail.msg -signer newsign.pem -out mail2.msg
452 The MIME parser isn't very clever: it seems to handle most messages that I've
453 thrown at it but it may choke on others.
455 The code currently will only write out the signer's certificate to a file: if
456 the signer has a separate encryption certificate this must be manually
457 extracted. There should be some heuristic that determines the correct
458 encryption certificate.
460 Ideally a database should be maintained of a certificates for each email
463 The code doesn't currently take note of the permitted symmetric encryption
464 algorithms as supplied in the SMIMECapabilities signed attribute. This means the
465 user has to manually include the correct encryption algorithm. It should store
466 the list of permitted ciphers in a database and only use those.
468 No revocation checking is done on the signer's certificate.
470 The current code can only handle S/MIME v2 messages, the more complex S/MIME v3
471 structures may cause parsing errors.
475 The use of multiple B<-signer> options and the B<-resign> command were first
476 added in OpenSSL 1.0.0