Provided by: libssl-doc_1.1.1c-1ubuntu4_all bug


       CMS_encrypt - create a CMS envelopedData structure


        #include <openssl/cms.h>

        CMS_ContentInfo *CMS_encrypt(STACK_OF(X509) *certs, BIO *in,
                                     const EVP_CIPHER *cipher, unsigned int flags);


       CMS_encrypt() creates and returns a CMS EnvelopedData structure. certs is a list of
       recipient certificates. in is the content to be encrypted.  cipher is the symmetric cipher
       to use. flags is an optional set of flags.


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

       EVP_des_ede3_cbc() (triple DES) is the algorithm of choice for S/MIME use because most
       clients will support it.

       The algorithm passed in the cipher parameter must support ASN1 encoding of its parameters.

       Many browsers implement a "sign and encrypt" option which is simply an S/MIME
       envelopedData containing an S/MIME signed message. This can be readily produced by storing
       the S/MIME signed message in a memory BIO and passing it to CMS_encrypt().

       The following flags can be passed in the flags parameter.

       If the CMS_TEXT flag is set MIME headers for type text/plain are prepended to the data.

       Normally the supplied content is translated into MIME canonical format (as required by the
       S/MIME specifications) if CMS_BINARY is set no translation occurs. This option should be
       used if the supplied data is in binary format otherwise the translation will corrupt it.
       If CMS_BINARY is set then CMS_TEXT is ignored.

       OpenSSL will by default identify recipient certificates using issuer name and serial
       number. If CMS_USE_KEYID is set it will use the subject key identifier value instead. An
       error occurs if all recipient certificates do not have a subject key identifier extension.

       If the CMS_STREAM flag is set a partial CMS_ContentInfo structure is returned suitable for
       streaming I/O: no data is read from the BIO in.

       If the CMS_PARTIAL flag is set a partial CMS_ContentInfo structure is returned to which
       additional recipients and attributes can be added before finalization.

       The data being encrypted is included in the CMS_ContentInfo structure, unless CMS_DETACHED
       is set in which case it is omitted. This is rarely used in practice and is not supported
       by SMIME_write_CMS().


       If the flag CMS_STREAM is set the returned CMS_ContentInfo structure is not complete and
       outputting its contents via a function that does not properly finalize the CMS_ContentInfo
       structure will give unpredictable results.

       Several functions including SMIME_write_CMS(), i2d_CMS_bio_stream(),
       PEM_write_bio_CMS_stream() finalize the structure. Alternatively finalization can be
       performed by obtaining the streaming ASN1 BIO directly using BIO_new_CMS().

       The recipients specified in certs use a CMS KeyTransRecipientInfo info structure.
       KEKRecipientInfo is also supported using the flag CMS_PARTIAL and

       The parameter certs may be NULL if CMS_PARTIAL is set and recipients added later using
       CMS_add1_recipient_cert() or CMS_add0_recipient_key().


       CMS_encrypt() returns either a CMS_ContentInfo structure or NULL if an error occurred. The
       error can be obtained from ERR_get_error(3).


       ERR_get_error(3), CMS_decrypt(3)


       The CMS_STREAM flag was first supported in OpenSSL 1.0.0.


       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 <>.