| Index: openssl/doc/crypto/CMS_encrypt.pod
|
| ===================================================================
|
| --- openssl/doc/crypto/CMS_encrypt.pod (revision 0)
|
| +++ openssl/doc/crypto/CMS_encrypt.pod (revision 0)
|
| @@ -0,0 +1,96 @@
|
| +=pod
|
| +
|
| +=head1 NAME
|
| +
|
| + CMS_encrypt - create a CMS envelopedData structure
|
| +
|
| +=head1 SYNOPSIS
|
| +
|
| + #include <openssl/cms.h>
|
| +
|
| + CMS_ContentInfo *CMS_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, unsigned int flags);
|
| +
|
| +=head1 DESCRIPTION
|
| +
|
| +CMS_encrypt() creates and returns a CMS EnvelopedData structure. B<certs>
|
| +is a list of recipient certificates. B<in> is the content to be encrypted.
|
| +B<cipher> is the symmetric cipher to use. B<flags> is an optional set of flags.
|
| +
|
| +=head1 NOTES
|
| +
|
| +Only certificates carrying RSA keys are supported so the recipient certificates
|
| +supplied to this function must all contain RSA public keys, though they do not
|
| +have to be signed using the RSA algorithm.
|
| +
|
| +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 B<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 B<flags> parameter.
|
| +
|
| +If the B<CMS_TEXT> flag is set MIME headers for type B<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 B<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 B<CMS_BINARY> is set then
|
| +B<CMS_TEXT> is ignored.
|
| +
|
| +OpenSSL will by default identify recipient certificates using issuer name
|
| +and serial number. If B<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 B<CMS_STREAM> flag is set a partial B<CMS_ContentInfo> structure is
|
| +returned suitable for streaming I/O: no data is read from the BIO B<in>.
|
| +
|
| +If the B<CMS_PARTIAL> flag is set a partial B<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
|
| +B<CMS_DETACHED> is set in which case it is omitted. This is rarely used in
|
| +practice and is not supported by SMIME_write_CMS().
|
| +
|
| +=head1 NOTES
|
| +
|
| +If the flag B<CMS_STREAM> is set the returned B<CMS_ContentInfo> structure is
|
| +B<not> complete and outputting its contents via a function that does not
|
| +properly finalize the B<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 B<BIO> directly using
|
| +BIO_new_CMS().
|
| +
|
| +The recipients specified in B<certs> use a CMS KeyTransRecipientInfo info
|
| +structure. KEKRecipientInfo is also supported using the flag B<CMS_PARTIAL>
|
| +and CMS_add0_recipient_key().
|
| +
|
| +The parameter B<certs> may be NULL if B<CMS_PARTIAL> is set and recipients
|
| +added later using CMS_add1_recipient_cert() or CMS_add0_recipient_key().
|
| +
|
| +=head1 RETURN VALUES
|
| +
|
| +CMS_encrypt() returns either a CMS_ContentInfo structure or NULL if an error
|
| +occurred. The error can be obtained from ERR_get_error(3).
|
| +
|
| +=head1 SEE ALSO
|
| +
|
| +L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_decrypt(3)|CMS_decrypt(3)>
|
| +
|
| +=head1 HISTORY
|
| +
|
| +CMS_decrypt() was added to OpenSSL 0.9.8
|
| +The B<CMS_STREAM> flag was first supported in OpenSSL 1.0.0.
|
| +
|
| +=cut
|
|
|