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CMS(1)				    OpenSSL				CMS(1)

       openssl-cms, cms	- CMS utility

       openssl cms [-help] [-encrypt] [-decrypt] [-sign] [-verify] [-cmsout]
       [-resign] [-data_create]	[-data_out] [-digest_create] [-digest_verify]
       [-compress] [-uncompress] [-EncryptedData_encrypt] [-sign_receipt]
       [-verify_receipt	receipt] [-in filename]	[-inform SMIME|PEM|DER]
       [-rctform SMIME|PEM|DER]	[-out filename]	[-outform SMIME|PEM|DER]
       [-stream	-indef -noindef] [-noindef] [-content filename]	[-text]
       [-noout]	[-print] [-CAfile file]	[-CApath dir] [-no-CAfile]
       [-no-CApath] [-attime timestamp]	[-check_ss_sig]	[-crl_check]
       [-crl_check_all]	[-explicit_policy] [-extended_crl] [-ignore_critical]
       [-inhibit_any] [-inhibit_map] [-no_check_time] [-partial_chain]
       [-policy	arg] [-policy_check] [-policy_print] [-purpose purpose]
       [-suiteB_128] [-suiteB_128_only]	[-suiteB_192] [-trusted_first]
       [-no_alt_chains]	[-use_deltas] [-auth_level num]	[-verify_depth num]
       [-verify_email email] [-verify_hostname hostname] [-verify_ip ip]
       [-verify_name name] [-x509_strict] [-md digest] [-cipher] [-nointern]
       [-noverify] [-nocerts] [-noattr]	[-nosmimecap] [-binary]	[-crlfeol]
       [-asciicrlf] [-nodetach]	[-certfile file] [-certsout file] [-signer
       file] [-recip file] [-keyid] [-receipt_request_all]
       [-receipt_request_first]	[-receipt_request_from emailaddress]
       [-receipt_request_to emailaddress] [-receipt_request_print] [-secretkey
       key] [-secretkeyid id] [-econtent_type type] [-inkey file] [-keyopt
       name:parameter] [-passin	arg] [-rand file...]  [-writerand file]
       [cert.pem...]  [-to addr] [-from	addr] [-subject	subj] [cert.pem]...

       The cms command handles S/MIME v3.1 mail. It can	encrypt, decrypt, sign
       and verify, compress and	uncompress S/MIME messages.

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

	   Print out a usage message.

	   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. The actual CMS type is <B>EnvelopedData<B>.

	   Note	that no	revocation check is done for the recipient cert, so if
	   that	key has	been compromised, others may be	able to	decrypt	the

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

	   This	option sets the	CMS_DEBUG_DECRYPT flag.	This option should be
	   used	with caution: see the notes section below.

	   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
	   outputs the signed data. Both clear text and	opaque signing is

	   Takes an input message and writes out a PEM encoded CMS structure.

	   Resign a message: take an existing message and one or more new

	   Create a CMS	Data type.

	   Data	type and output	the content.

	   Create a CMS	DigestedData type.

	   Verify a CMS	DigestedData type and output the content.

	   Create a CMS	CompressedData type. OpenSSL must be compiled with
	   zlib	support	for this option	to work, otherwise it will output an

	   Uncompress a	CMS CompressedData type	and output the content.
	   OpenSSL must	be compiled with zlib support for this option to work,
	   otherwise it	will output an error.

	   Encrypt content using supplied symmetric key	and algorithm using a
	   CMS EncryptedData type and output the content.

	   Generate and	output a signed	receipt	for the	supplied message. The
	   input message must contain a	signed receipt request.	Functionality
	   is otherwise	similar	to the -sign operation.

       -verify_receipt receipt
	   Verify a signed receipt in filename receipt.	The input message must
	   contain the original	receipt	request. Functionality is otherwise
	   similar to the -verify operation.

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

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

       -rctform	SMIME|PEM|DER
	   Specify the format for a signed receipt for use with	the
	   -receipt_verify operation.

       -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 CMS	structure. The default
	   is SMIME which writes an S/MIME format message. PEM and DER format
	   change this to write	PEM and	DER format CMS structures instead.
	   This	currently only affects the output format of the	CMS structure,
	   if no CMS structure is being	output (for example with -verify or
	   -decrypt) this option has no	effect.

       -stream -indef -noindef
	   The -stream and -indef options are equivalent and enable streaming
	   I/O for encoding operations.	This permits single pass processing of
	   data	without	the need to hold the entire contents in	memory,
	   potentially supporting very large files. Streaming is automatically
	   set for S/MIME signing with detached	data if	the output format is
	   SMIME it is currently off by	default	for all	other operations.

	   Disable streaming I/O where it would	produce	and indefinite length
	   constructed encoding. This option currently has no effect. In
	   future streaming will be enabled by default on all relevant
	   operations and this option will disable it.

       -content	filename
	   This	specifies a file containing the	detached content, this is only
	   useful with the -verify command. This is only usable	if the CMS
	   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
	   supplied 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.

	   For the -cmsout operation do	not output the parsed CMS structure.
	   This	is useful when combined	with the -print	option or if the
	   syntax of the CMS structure is being	checked.

	   For the -cmsout operation print out all fields of the CMS
	   structure. This is mainly useful for	testing	purposes.

       -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.

	   Do not load the trusted CA certificates from	the default file

	   Do not load the trusted CA certificates from	the default directory

       -md digest
	   Digest algorithm to use when	signing	or resigning. If not present
	   then	the default digest algorithm for the signing key will be used
	   (usually SHA1).

	   The encryption algorithm to use. For	example	triple DES (168	bits)
	   - -des3 or 256 bit AES - -aes256. Any standard algorithm name (as
	   used	by the EVP_get_cipherbyname() function)	can also be used
	   preceded by a dash, for example -aes-128-cbc. See enc(1) for	a list
	   of ciphers supported	by your	version	of OpenSSL.

	   If not specified triple DES is used.	Only used with -encrypt	and
	   -EncryptedData_create commands.

	   When	verifying a message normally certificates (if any) included in
	   the message are searched for	the signing certificate. With this
	   option 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.

	   When	signing	a message the signer's certificate is normally
	   included 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.

	   Exclude the list of supported algorithms from signed	attributes,
	   other options such as signing time and content type are still

	   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.

	   Normally the	output file uses a single LF as	end of line. When this
	   option is present CRLF is used instead.

	   When	signing	use ASCII CRLF format canonicalisation.	This strips
	   trailing whitespace from all	lines, deletes trailing	blank lines at
	   EOF and sets	the encapsulated content type. This option is normally
	   used	with detached content and an output signature format of	DER.
	   This	option is not normally needed when verifying as	it is enabled
	   automatically if the	encapsulated content format is detected.

	   When	signing	a message use opaque signing: this form	is more
	   resistant 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.

       -certsout file
	   Any certificates contained in the message are written to file.

       -signer file
	   A signing certificate when signing or resigning a message, this
	   option can be used multiple times if	more than one signer is
	   required. If	a message is being verified then the signers
	   certificates	will be	written	to this	file if	the verification was

       -recip file
	   When	decrypting a message this specifies the	recipients
	   certificate.	The certificate	must match one of the recipients of
	   the message or an error occurs.

	   When	encrypting a message this option may be	used multiple times to
	   specify each	recipient. This	form must be used if customised
	   parameters are required (for	example	to specify RSA-OAEP).

	   Only	certificates carrying RSA, Diffie-Hellman or EC	keys are
	   supported by	this option.

	   Use subject key identifier to identify certificates instead of
	   issuer name and serial number. The supplied certificate must
	   include a subject key identifier extension. Supported by -sign and
	   -encrypt options.

       -receipt_request_all, -receipt_request_first
	   For -sign option include a signed receipt request. Indicate
	   requests should be provided by all recipient	or first tier
	   recipients (those mailed directly and not from a mailing list).
	   Ignored it -receipt_request_from is included.

       -receipt_request_from emailaddress
	   For -sign option include a signed receipt request. Add an explicit
	   email address where receipts	should be supplied.

       -receipt_request_to emailaddress
	   Add an explicit email address where signed receipts should be sent
	   to. This option must	but supplied if	a signed receipt it requested.

	   For the -verify operation print out the contents of any signed
	   receipt requests.

       -secretkey key
	   Specify symmetric key to use. The key must be supplied in hex
	   format and be consistent with the algorithm used. Supported by the
	   -EncryptedData_encrypt -EncryptedData_decrypt, -encrypt and
	   -decrypt options. When used with -encrypt or	-decrypt the supplied
	   key is used to wrap or unwrap the content encryption	key using an
	   AES key in the KEKRecipientInfo type.

       -secretkeyid id
	   The key identifier for the supplied symmetric key for
	   KEKRecipientInfo type.  This	option must be present if the
	   -secretkey option is	used with -encrypt. With -decrypt operations
	   the id is used to locate the	relevant key if	it is not supplied
	   then	an attempt is used to decrypt any KEKRecipientInfo structures.

       -econtent_type type
	   Set the encapsulated	content	type to	type if	not supplied the Data
	   type	is used. The type argument can be any valid OID	name in	either
	   text	or numerical format.

       -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. When signing this option can be
	   used	multiple times to specify successive keys.

       -keyopt name:opt
	   For signing and encryption this option can be used multiple times
	   to set customised parameters	for the	preceding key or certificate.
	   It can currently be used to set RSA-PSS for signing,	RSA-OAEP for
	   encryption or to modify default parameters for ECDH.

       -passin arg
	   The private key password source. For	more information about the
	   format of arg see "Pass Phrase Options" in openssl(1).

       -rand file...
	   A file or files containing random data used to seed the random
	   number generator.  Multiple files can be specified separated	by an
	   OS-dependent	character.  The	separator is ; for MS-Windows, , for
	   OpenVMS, and	: for all others.

       [-writerand file]
	   Writes random data to the specified file upon exit.	This can be
	   used	with a subsequent -rand	flag.

	   One or more certificates of message recipients: used	when
	   encrypting 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.

       -attime,	-check_ss_sig, -crl_check, -crl_check_all, -explicit_policy,
       -extended_crl, -ignore_critical,	-inhibit_any, -inhibit_map,
       -no_alt_chains, -no_check_time, -partial_chain, -policy,	-policy_check,
       -policy_print, -purpose,	-suiteB_128, -suiteB_128_only, -suiteB_192,
       -trusted_first, -use_deltas, -auth_level, -verify_depth,	-verify_email,
       -verify_hostname, -verify_ip, -verify_name, -x509_strict
	   Set various certificate chain validation options. See the verify(1)
	   manual page for details.

       The MIME	message	must be	sent without any blank lines between the
       headers 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
       necessary MIME headers or many S/MIME clients won't display it properly
       (if at all). You	can use	the -text option to automatically add plain
       text headers.

       A "signed and encrypted"	message	is one where a signed message is then
       encrypted. This can be produced by encrypting an	already	signed
       message:	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	CMS enveloped data: CMS
       encrypted data is used for other	purposes.

       The -resign option uses an existing message digest when adding a	new
       signer. This means that attributes must be present in at	least one
       existing	signer using the same message digest or	this operation will

       The -stream and -indef options enable streaming I/O support.  As	a
       result the encoding is BER using	indefinite length constructed encoding
       and no longer DER. Streaming is supported for the -encrypt operation
       and the -sign operation if the content is not detached.

       Streaming is always used	for the	-sign operation	with detached data but
       since the content is no longer part of the CMS structure	the encoding
       remains DER.

       If the -decrypt option is used without a	recipient certificate then an
       attempt is made to locate the recipient by trying each potential
       recipient in turn using the supplied private key. To thwart the MMA
       attack (Bleichenbacher's	attack on PKCS #1 v1.5 RSA padding) all
       recipients are tried whether they succeed or not	and if no recipients
       match the message is "decrypted"	using a	random key which will
       typically output	garbage.  The -debug_decrypt option can	be used	to
       disable the MMA attack protection and return an error if	no recipient
       can be found: this option should	be used	with caution. For a fuller
       description see CMS_decrypt(3)).

       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 CMS 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.

       The smime utility can only process the older PKCS#7 format. The cms
       utility supports	Cryptographic Message Syntax format. Use of some
       features	will result in messages	which cannot be	processed by
       applications which only support the older format. These are detailed

       The use of the -keyid option with -sign or -encrypt.

       The -outform PEM	option uses different headers.

       The -compress option.

       The -secretkey option when used with -encrypt.

       The use of PSS with -sign.

       The use of OAEP or non-RSA keys with -encrypt.

       Additionally the	-EncryptedData_create and -data_create type cannot be
       processed by the	older smime command.

       Create a	cleartext signed message:

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

       Create an opaque	signed message

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

       Create a	signed message with two	signers, use key identifier:

	openssl	cms -sign -in message.txt -text	-out mail.msg \
	       -signer mycert.pem -signer othercert.pem	-keyid

       Send a signed message under Unix	directly to sendmail, including

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

       Send encrypted mail using triple	DES:

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

       Sign and	encrypt	mail:

	openssl	cms -sign -in ml.txt -signer my.pem -text \
	       | openssl cms -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	cms -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
       signature by line wrapping the base64 encoded structure and surrounding
       it with:

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

       and using the command,

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

       alternatively you can base64 decode the signature and use

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

       Create an encrypted message using 128 bit Camellia:

	openssl	cms -encrypt -in plain.txt -camellia128	-out mail.msg cert.pem

       Add a signer to an existing message:

	openssl	cms -resign -in	mail.msg -signer newsign.pem -out mail2.msg

       Sign mail using RSA-PSS:

	openssl	cms -sign -in message.txt -text	-out mail.msg \
	       -signer mycert.pem -keyopt rsa_padding_mode:pss

       Create encrypted	mail using RSA-OAEP:

	openssl	cms -encrypt -in plain.txt -out	mail.msg \
	       -recip cert.pem -keyopt rsa_padding_mode:oaep

       Use SHA256 KDF with an ECDH certificate:

	openssl	cms -encrypt -in plain.txt -out	mail.msg \
	       -recip ecdhcert.pem -keyopt ecdh_kdf_md:sha256

       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
       encryption algorithms as	supplied in the	SMIMECapabilities signed
       attribute. this means the user has to manually include the correct
       encryption algorithm. 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 use of multiple -signer options and the -resign command were	first
       added in	OpenSSL	1.0.0.

       The keyopt option was added in OpenSSL 1.0.2.

       Support for RSA-OAEP and	RSA-PSS	was added in OpenSSL 1.0.2.

       The use of non-RSA keys with -encrypt and -decrypt was added in OpenSSL

       The -no_alt_chains option was added in OpenSSL 1.0.2b.

       Copyright 2008-2021 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (the "License").  You	may not	use
       this file except	in compliance with the License.	 You can obtain	a copy
       in the file LICENSE in the source distribution or at

1.1.1k				  2021-03-25				CMS(1)


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