CMS(1SSL)                           OpenSSL                          CMS(1SSL)

       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 the PASS PHRASE ARGUMENTS section 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 2008-2018 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

1.1.1f                            2023-10-10                         CMS(1SSL)
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