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SMIME(1)			    OpenSSL			      SMIME(1)

       smime - S/MIME utility

       openssl smime [-encrypt]	[-decrypt] [-sign] [-verify] [-pk7out] [-des]
       [-des3] [-rc2-40] [-rc2-64] [-rc2-128] [-aes128]	[-aes192] [-aes256]
       [-in file] [-certfile file] [-signer file] [-recip  file] [-inform
       SMIME|PEM|DER] [-passin arg] [-inkey file] [-out	file] [-outform
       SMIME|PEM|DER] [-content	file] [-to addr] [-from	ad] [-subject s]
       [-text] [-rand file(s)] [cert.pem]...

       The smime command handles S/MIME	mail. It can encrypt, decrypt, sign
       and verify S/MIME messages.

       There are five operation	options	that set the type of operation to be
       performed.  The meaning of the other options varies according to	the
       operation type.

	   encrypt mail	for the	given recipient	certificates. Input file is
	   the message to be encrypted.	The output file	is the encrypted mail
	   in MIME format.

	   decrypt mail	using the supplied certificate and private key.	Ex-
	   pects an encrypted mail message in MIME format for the input	file.
	   The decrypted mail is written to the	output file.

	   sign	mail using the supplied	certificate and	private	key. Input
	   file	is the message to be signed. The signed	message	in MIME	format
	   is written to the output file.

	   verify signed mail. Expects a signed	mail message on	input and out-
	   puts	the signed data. Both clear text and opaque signing is sup-

	   takes an input message and writes out a PEM encoded PKCS#7 struc-

       -in filename
	   the input message to	be encrypted or	signed or the MIME message to
	   be decrypted	or verified.

       -inform SMIME|PEM|DER
	   this	specifies the input format for the PKCS#7 structure. The de-
	   fault is SMIME which	reads an S/MIME	format message.	PEM and	DER
	   format change this to expect	PEM and	DER format PKCS#7 structures
	   instead. This currently only	affects	the input format of the	PKCS#7
	   structure, if no PKCS#7 structure is	being input (for example with
	   -encrypt or -sign) this option has no effect.

       -out filename
	   the message text that has been decrypted or verified	or the output
	   MIME	format message that has	been signed or verified.

       -outform	SMIME|PEM|DER
	   this	specifies the output format for	the PKCS#7 structure. The de-
	   fault is SMIME which	write an S/MIME	format message.	PEM and	DER
	   format change this to write PEM and DER format PKCS#7 structures
	   instead. This currently only	affects	the output format of the
	   PKCS#7 structure, if	no PKCS#7 structure is being output (for exam-
	   ple with -verify or -decrypt) this option has no effect.

       -content	filename
	   This	specifies a file containing the	detached content, this is only
	   useful with the -verify command. This is only usable	if the PKCS#7
	   structure is	using the detached signature form where	the content is
	   not included. This option will override any content if the input
	   format is S/MIME and	it uses	the multipart/signed MIME content

	   this	option adds plain text (text/plain) MIME headers to the	sup-
	   plied message if encrypting or signing. If decrypting or verifying
	   it strips off text headers: if the decrypted	or verified message is
	   not of MIME type text/plain then an error occurs.

       -CAfile file
	   a file containing trusted CA	certificates, only used	with -verify.

       -CApath dir
	   a directory containing trusted CA certificates, only	used with
	   -verify. This directory must	be a standard certificate directory:
	   that	is a hash of each subject name (using x509 -hash) should be
	   linked to each certificate.

       -des -des3 -rc2-40 -rc2-64 -rc2-128 -aes128 -aes192 -aes256
	   the encryption algorithm to use. DES	(56 bits), triple DES (168
	   bits), 40, 64 or 128	bit RC2	or 128,	192 or 256 bit AES respec-
	   tively.  If not specified 40	bit RC2	is used. Only used with	-en-

	   when	verifying a message normally certificates (if any) included in
	   the message are searched for	the signing certificate. With this op-
	   tion	only the certificates specified	in the -certfile option	are
	   used.  The supplied certificates can	still be used as untrusted CAs

	   do not verify the signers certificate of a signed message.

	   do not do chain verification	of signers certificates: that is don't
	   use the certificates	in the signed message as untrusted CAs.

	   don't try to	verify the signatures on the message.

	   when	signing	a message the signer's certificate is normally in-
	   cluded with this option it is excluded. This	will reduce the	size
	   of the signed message but the verifier must have a copy of the
	   signers certificate available locally (passed using the -certfile
	   option for example).

	   normally when a message is signed a set of attributes are included
	   which include the signing time and supported	symmetric algorithms.
	   With	this option they are not included.

	   normally the	input message is converted to "canonical" format which
	   is effectively using	CR and LF as end of line: as required by the
	   S/MIME specification. When this option is present no	translation
	   occurs. This	is useful when handling	binary data which may not be
	   in MIME format.

	   when	signing	a message use opaque signing: this form	is more	resis-
	   tant	to translation by mail relays but it cannot be read by mail
	   agents that do not support S/MIME.  Without this option cleartext
	   signing with	the MIME type multipart/signed is used.

       -certfile file
	   allows additional certificates to be	specified. When	signing	these
	   will	be included with the message. When verifying these will	be
	   searched for	the signers certificates. The certificates should be
	   in PEM format.

       -signer file
	   the signers certificate when	signing	a message. If a	message	is be-
	   ing verified	then the signers certificates will be written to this
	   file	if the verification was	successful.

       -recip file
	   the recipients certificate when decrypting a	message. This certifi-
	   cate	must match one of the recipients of the	message	or an error

       -inkey file
	   the private key to use when signing or decrypting. This must	match
	   the corresponding certificate. If this option is not	specified then
	   the private key must	be included in the certificate file specified
	   with	the -recip or -signer file.

       -passin arg
	   the private key password source. For	more information about the
	   format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).

       -rand file(s)
	   a file or files containing random data used to seed the random num-
	   ber generator, or an	EGD socket (see	RAND_egd(3)).  Multiple	files
	   can be specified separated by a OS-dependent	character.  The	sepa-
	   rator is ; for MS-Windows, ,	for OpenVMS, and : for all others.

	   one or more certificates of message recipients: used	when encrypt-
	   ing a message.

       -to, -from, -subject
	   the relevant	mail headers. These are	included outside the signed
	   portion of a	message	so they	may be included	manually. If signing
	   then	many S/MIME mail clients check the signers certificate's email
	   address matches that	specified in the From: address.

       The MIME	message	must be	sent without any blank lines between the head-
       ers and the output. Some	mail programs will automatically add a blank
       line. Piping the	mail directly to sendmail is one way to	achieve	the
       correct format.

       The supplied message to be signed or encrypted must include the neces-
       sary MIME headers or many S/MIME	clients	wont display it	properly (if
       at all).	You can	use the	-text option to	automatically add plain	text

       A "signed and encrypted"	message	is one where a signed message is then
       encrypted. This can be produced by encrypting an	already	signed mes-
       sage: see the examples section.

       This version of the program only	allows one signer per message but it
       will verify multiple signers on received	messages. Some S/MIME clients
       choke if	a message contains multiple signers. It	is possible to sign
       messages	"in parallel" by signing an already signed message.

       The options -encrypt and	-decrypt reflect common	usage in S/MIME
       clients.	Strictly speaking these	process	PKCS#7 enveloped data: PKCS#7
       encrypted data is used for other	purposes.

       0   the operation was completely	successfully.

       1   an error occurred parsing the command options.

       2   one of the input files could	not be read.

       3   an error occurred creating the PKCS#7 file or when reading the MIME

       4   an error occurred decrypting	or verifying the message.

       5   the message was verified correctly but an error occurred writing
	   out the signers certificates.

       Create a	cleartext signed message:

	openssl	smime -sign -in	message.txt -text -out mail.msg	\
	       -signer mycert.pem

       Create and opaque signed	message

	openssl	smime -sign -in	message.txt -text -out mail.msg	-nodetach \
	       -signer mycert.pem

       Create a	signed message,	include	some additional	certificates and read
       the private key from another file:

	openssl	smime -sign -in	in.txt -text -out mail.msg \
	       -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem

       Send a signed message under Unix	directly to sendmail, including	head-

	openssl	smime -sign -in	in.txt -text -signer mycert.pem	\
	       -from -to someone@somewhere \
	       -subject	"Signed	message" | sendmail someone@somewhere

       Verify a	message	and extract the	signer's certificate if	successful:

	openssl	smime -verify -in mail.msg -signer user.pem -out signedtext.txt

       Send encrypted mail using triple	DES:

	openssl	smime -encrypt -in in.txt -from \
	       -to someone@somewhere -subject "Encrypted message" \
	       -des3 user.pem -out mail.msg

       Sign and	encrypt	mail:

	openssl	smime -sign -in	ml.txt -signer my.pem -text \
	       | openssl smime -encrypt	-out mail.msg \
	       -from -to someone@somewhere \
	       -subject	"Signed	and Encrypted message" -des3 user.pem

       Note: the encryption command does not include the -text option because
       the message being encrypted already has MIME headers.

       Decrypt mail:

	openssl	smime -decrypt -in mail.msg -recip mycert.pem -inkey key.pem

       The output from Netscape	form signing is	a PKCS#7 structure with	the
       detached	signature format. You can use this program to verify the sig-
       nature by line wrapping the base64 encoded structure and	surrounding it

	-----BEGIN PKCS7-----
	-----END PKCS7-----

       and using the command,

	openssl	smime -verify -inform PEM -in signature.pem -content content.txt

       alternatively you can base64 decode the signature and use

	openssl	smime -verify -inform DER -in signature.der -content content.txt

       The MIME	parser isn't very clever: it seems to handle most messages
       that I've thrown	at it but it may choke on others.

       The code	currently will only write out the signer's certificate to a
       file: if	the signer has a separate encryption certificate this must be
       manually	extracted. There should	be some	heuristic that determines the
       correct encryption certificate.

       Ideally a database should be maintained of a certificates for each
       email address.

       The code	doesn't	currently take note of the permitted symmetric encryp-
       tion algorithms as supplied in the SMIMECapabilities signed attribute.
       this means the user has to manually include the correct encryption al-
       gorithm.	It should store	the list of permitted ciphers in a database
       and only	use those.

       No revocation checking is done on the signer's certificate.

       The current code	can only handle	S/MIME v2 messages, the	more complex
       S/MIME v3 structures may	cause parsing errors.

0.9.7d				  2005-02-25			      SMIME(1)


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