smime_read_cms(3ssl) [debian man page]

SMIME_read_CMS(3SSL)						      OpenSSL						      SMIME_read_CMS(3SSL)

NAME

	SMIME_read_CMS - parse S/MIME message.

SYNOPSIS

	#include <openssl/cms.h>

	CMS_ContentInfo *SMIME_read_CMS(BIO *in, BIO **bcont);

DESCRIPTION

       SMIME_read_CMS() parses a message in S/MIME format.

       in is a BIO to read the message from.

       If cleartext signing is used then the content is saved in a memory bio which is written to *bcont, otherwise *bcont is set to NULL.

       The parsed CMS_ContentInfo structure is returned or NULL if an error occurred.

NOTES

       If *bcont is not NULL then the message is clear text signed. *bcont can then be passed to CMS_verify() with the CMS_DETACHED flag set.

       Otherwise the type of the returned structure can be determined using CMS_get0_type().

       To support future functionality if bcont is not NULL *bcont should be initialized to NULL. For example:

	BIO *cont = NULL;
	CMS_ContentInfo *cms;

	cms = SMIME_read_CMS(in, &cont);

BUGS

       The MIME parser used by SMIME_read_CMS() is somewhat primitive.	While it will handle most S/MIME messages more complex compound formats
       may not work.

       The parser assumes that the CMS_ContentInfo structure is always base64 encoded and will not handle the case where it is in binary format or
       uses quoted printable format.

       The use of a memory BIO to hold the signed content limits the size of message which can be processed due to memory restraints: a streaming
       single pass option should be available.

RETURN VALUES

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

SEE ALSO

       ERR_get_error(3), CMS_type(3) SMIME_read_CMS(3), CMS_sign(3), CMS_verify(3), CMS_encrypt(3) CMS_decrypt(3)

HISTORY

       SMIME_read_CMS() was added to OpenSSL 0.9.8

1.0.1e								    2013-02-11						      SMIME_read_CMS(3SSL)

CMS_encrypt(3SSL)						      OpenSSL							 CMS_encrypt(3SSL)

NAME

	CMS_encrypt - create a CMS envelopedData structure

SYNOPSIS

	#include <openssl/cms.h>

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

DESCRIPTION

       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.

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 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().

NOTES

       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 CMS_add0_recipient_key().

       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().

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).

SEE ALSO

       ERR_get_error(3), CMS_decrypt(3)

HISTORY

       CMS_decrypt() was added to OpenSSL 0.9.8 The CMS_STREAM flag was first supported in OpenSSL 1.0.0.

1.0.1e								    2013-02-11							 CMS_encrypt(3SSL)