X-Git-Url: https://code.wpia.club/?a=blobdiff_plain;f=lib%2Fopenssl%2Fdoc%2Fcrypto%2FCMS_encrypt.pod;fp=lib%2Fopenssl%2Fdoc%2Fcrypto%2FCMS_encrypt.pod;h=1ee5b275ec82b980888814e356bf84b862cf59c8;hb=9ff1530871deeb0f7eaa35ca0db6630724045e4a;hp=0000000000000000000000000000000000000000;hpb=25b73076b01ae059da1a2e9a1677e00788ada620;p=cassiopeia.git diff --git a/lib/openssl/doc/crypto/CMS_encrypt.pod b/lib/openssl/doc/crypto/CMS_encrypt.pod new file mode 100644 index 0000000..1ee5b27 --- /dev/null +++ b/lib/openssl/doc/crypto/CMS_encrypt.pod @@ -0,0 +1,96 @@ +=pod + +=head1 NAME + + CMS_encrypt - create a CMS envelopedData structure + +=head1 SYNOPSIS + + #include + + 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 +is a list of recipient certificates. B is the content to be encrypted. +B is the symmetric cipher to use. B 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 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 parameter. + +If the B flag is set MIME headers for type B are +prepended to the data. + +Normally the supplied content is translated into MIME canonical format (as +required by the S/MIME specifications) if B 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 is set then +B is ignored. + +OpenSSL will by default identify recipient certificates using issuer name +and serial number. If B 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 flag is set a partial B structure is +returned suitable for streaming I/O: no data is read from the BIO B. + +If the B flag is set a partial B 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 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 is set the returned B structure is +B complete and outputting its contents via a function that does not +properly finalize the B 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 directly using +BIO_new_CMS(). + +The recipients specified in B use a CMS KeyTransRecipientInfo info +structure. KEKRecipientInfo is also supported using the flag B +and CMS_add0_recipient_key(). + +The parameter B may be NULL if B 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, L + +=head1 HISTORY + +CMS_decrypt() was added to OpenSSL 0.9.8 +The B flag was first supported in OpenSSL 1.0.0. + +=cut