CMSEncoder.h   [plain text]


/*
 * Copyright (c) 2006-2010 Apple Inc. All Rights Reserved.
 * 
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

/*
 * CMSEncoder.h - encode, sign, and/or encrypt messages in the Cryptographic
 *				  Message Syntax (CMS), per RFC 3852.
 *
 * A CMS message can be signed, encrypted, or both. A message can be signed by
 * an arbitrary number of signers; in this module, signers are expressed as
 * SecIdentityRefs. A message can be encrypted for an arbitrary number of
 * recipients; recipients are expressed here as SecCertificateRefs. 
 * 
 * In CMS terminology, this module performs encryption using the EnvelopedData 
 * ContentType and signing using the SignedData ContentType.
 *
 * If the message is both signed and encrypted, it uses "nested ContentInfos" 
 * in CMS terminology; in this implementation, signed & encrypted messages 
 * are implemented as an EnvelopedData containing a SignedData. 
 */
 
#ifndef _CMS_ENCODER_H_
#define _CMS_ENCODER_H_

#include <CoreFoundation/CoreFoundation.h>
#include <Security/cssmtype.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Opaque reference to a CMS encoder object. 
 * This is a CF object, with standard CF semantics; dispose of it
 * with CFRelease().
 */
typedef struct _CMSEncoder *CMSEncoderRef;

CFTypeID CMSEncoderGetTypeID(void)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Create a CMSEncoder. Result must eventually be freed via CFRelease().
 */
OSStatus CMSEncoderCreate(
	CMSEncoderRef		*cmsEncoderOut)	/* RETURNED */
	__OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/* 
 * Specify signers of the CMS message; implies that the message will be signed. 
 *
 * -- Caller can pass in one signer, as a SecIdentityRef, or an array of 
 *    signers, as a CFArray of SecIdentityRefs. 
 * -- Can be called multiple times. 
 * -- If the message is not to be signed, don't call this.  
 * -- If this is called, it must be called before the first call to 
 *    CMSEncoderUpdateContent().
 */
OSStatus CMSEncoderAddSigners(
	CMSEncoderRef		cmsEncoder,
	CFTypeRef			signerOrArray)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Obtain an array of signers as specified in CMSEncoderSetSigners(). 
 * Returns a NULL signers array if CMSEncoderSetSigners() has not been called.  
 * Caller must CFRelease the result. 
 */
OSStatus CMSEncoderCopySigners(
	CMSEncoderRef		cmsEncoder,
	CFArrayRef			*signersOut)		/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Specify recipients of the message. Implies that the message will 
 * be encrypted. 
 *
 * -- Caller can pass in one recipient, as a SecCertificateRef, or an 
 *    array of recipients, as a CFArray of SecCertificateRefs. 
 * -- Can be called multiple times. 
 * -- If the message is not to be encrypted, don't call this.  
 * -- If this is called, it must be called before the first call to 
 *    CMSEncoderUpdateContent().
 */
OSStatus CMSEncoderAddRecipients(
	CMSEncoderRef		cmsEncoder,
	CFTypeRef			recipientOrArray)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Obtain an array of recipients as specified in CMSEncoderSetRecipients(). 
 * Returns a NULL recipients array if CMSEncoderSetRecipients() has not been 
 * called.  
 * Caller must CFRelease the result. 
 */
OSStatus CMSEncoderCopyRecipients(
	CMSEncoderRef		cmsEncoder,
	CFArrayRef			*recipientsOut)	/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/* 
 * A signed message optionally includes the data to be signed. If the message
 * is *not* to include the data to be signed, call this function with a value
 * of TRUE for detachedContent. The default, if this function is not called,
 * is detachedContent=FALSE, i.e., the message contains the data to be signed.
 * 
 * -- Encrypted messages can not use detached content. (This restriction 
 *    also applies to messages that are both signed and encrypted.)
 * -- If this is called, it must be called before the first call to 
 *    CMSEncoderUpdateContent().
 */ 
OSStatus CMSEncoderSetHasDetachedContent(
	CMSEncoderRef		cmsEncoder,
	Boolean			detachedContent)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/* 
 * Obtain a Boolean indicating whether the current message will have detached 
 * content.
 * Returns the value specified in CMSEncoderHasDetachedContent() if that
 * function has been called; else returns the default FALSE.
 */
OSStatus CMSEncoderGetHasDetachedContent(
	CMSEncoderRef		cmsEncoder,
	Boolean			*detachedContentOut)	/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Optionally specify an eContentType OID for the inner EncapsulatedData for
 * a signed message. The default eContentType, used if this function is not
 * called, is id-data (which is the normal eContentType for applications such
 * as SMIME).
 *
 * If this is called, it must be called before the first call to 
 * CMSEncoderUpdateContent().
 *
 * NOTE: This function is deprecated in Mac OS X 10.7 and later;
 * please use CMSEncoderSetEncapsulatedContentTypeOID() instead.
 */
OSStatus CMSEncoderSetEncapsulatedContentType(
	CMSEncoderRef		cmsEncoder,
	const CSSM_OID	*eContentType)
	/* DEPRECATED_IN_MAC_OS_X_VERSION_10_7_AND_LATER; */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Optionally specify an eContentType OID for the inner EncapsulatedData for
 * a signed message. The default eContentTypeOID, used if this function is not
 * called, is id-data (which is the normal eContentType for applications such
 * as SMIME).
 *
 * The eContentTypeOID parameter may be specified as a CF string, e.g.:
 * CFSTR("1.2.840.113549.1.7.1")
 *
 * If this is called, it must be called before the first call to 
 * CMSEncoderUpdateContent().
 */
OSStatus CMSEncoderSetEncapsulatedContentTypeOID(
	CMSEncoderRef		cmsEncoder,
	CFTypeRef			eContentTypeOID)
    __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);

/*
 * Obtain the eContentType OID specified in CMSEncoderSetEncapsulatedContentType().
 * If CMSEncoderSetEncapsulatedContentType() has not been called this returns a 
 * NULL pointer.
 * The returned OID's data is in the same format as the data provided to 
 * CMSEncoderSetEncapsulatedContentType;, i.e., it's the encoded content of 
 * the OID, not including the tag and length bytes. 
 */
OSStatus CMSEncoderCopyEncapsulatedContentType(
	CMSEncoderRef		cmsEncoder,
	CFDataRef			*eContentTypeOut)		/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Signed CMS messages can contain arbitrary sets of certificates beyond those
 * indicating the identity of the signer(s). This function provides a means of 
 * adding these other certs. For normal signed messages it is not necessary to 
 * call this; the signer cert(s) and the intermediate certs needed to verify the
 * signer(s) will be included in the message implicitly. 
 *
 * -- Caller can pass in one cert, as a SecCertificateRef, or an array of certs,
 *    as a CFArray of SecCertificateRefs. 
 * -- If this is called, it must be called before the first call to 
 *    CMSEncoderUpdateContent().
 * -- There is a "special case" use of CMS messages which involves neither
 *    signing nor encryption, but does include certificates. This is commonly
 *    used to transport "bags" of certificates. When constructing such a 
 *    message, all an application needs to do is to create a CMSEncoderRef,
 *    call CMSEncoderAddSupportingCerts() one or more times, and then call 
 *    CMSEncoderCopyEncodedContent() to get the resulting cert bag. No 'content'
 *    need be specified. (This is in fact the primary intended use for
 *    this function.)
 */
OSStatus CMSEncoderAddSupportingCerts(
	CMSEncoderRef		cmsEncoder,
	CFTypeRef			certOrArray)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Obtain the SecCertificates provided in CMSEncoderAddSupportingCerts(). 
 * If CMSEncoderAddSupportingCerts() has not been called this will return a
 * NULL value for *certs.
 * Caller must CFRelease the result.
 */
OSStatus CMSEncoderCopySupportingCerts(
	CMSEncoderRef		cmsEncoder,
	CFArrayRef			*certsOut)			/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Standard signed attributes, optionally specified in 
 * CMSEncoderAddSignedAttributes().
 */
enum {
	kCMSAttrNone						= 0x0000,
    /* 
     * S/MIME Capabilities - identifies supported signature, encryption, and
     * digest algorithms.
     */
    kCMSAttrSmimeCapabilities			= 0x0001,
    /*
     * Indicates that a cert is the preferred cert for S/MIME encryption.
     */
    kCMSAttrSmimeEncryptionKeyPrefs		= 0x0002,
    /* 
     * Same as kCMSSmimeEncryptionKeyPrefs, using an attribute OID preferred
     * by Microsoft.
     */
    kCMSAttrSmimeMSEncryptionKeyPrefs	= 0x0004,
    /*
     * Include the signing time.
     */
    kCMSAttrSigningTime					= 0x0008
};
typedef uint32_t CMSSignedAttributes;

/*
 * Optionally specify signed attributes. Only meaningful when creating a 
 * signed message. If this is called, it must be called before
 * CMSEncoderUpdateContent().
 */
OSStatus CMSEncoderAddSignedAttributes(
	CMSEncoderRef		cmsEncoder,
	CMSSignedAttributes	signedAttributes)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Specification of what certificates to include in a signed message.
 */
enum {
	kCMSCertificateNone = 0,		/* don't include any certificates */
	kCMSCertificateSignerOnly,		/* only include signer certificate(s) */
	kCMSCertificateChain,			/* signer certificate chain up to but not 
									 *   including root certiticate */ 
	kCMSCertificateChainWithRoot	/* signer certificate chain including root */
};
typedef uint32_t CMSCertificateChainMode;

/* 
 * Optionally specify which certificates, if any, to include in a 
 * signed CMS message. The default, if this is not called, is
 * kCMSCertificateChain, in which case the signer cert plus all CA
 * certs needed to verify the signer cert, except for the root 
 * cert, are included.
 * If this is called, it must be called before
 * CMSEncoderUpdateContent().
 */
OSStatus CMSEncoderSetCertificateChainMode(
	CMSEncoderRef			cmsEncoder,
	CMSCertificateChainMode	chainMode)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/* 
 * Obtain indication of which signer certs are to be included
 * in a signed CMS message. 
 */
OSStatus CMSEncoderGetCertificateChainMode(
	CMSEncoderRef			cmsEncoder,
	CMSCertificateChainMode	*chainModeOut)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Feed content bytes into the encoder. 
 * Can be called multiple times. 
 * No 'setter' routines can be called after this function has been called. 
 */ 
OSStatus CMSEncoderUpdateContent(
	CMSEncoderRef		cmsEncoder,
	const void			*content,
	size_t				contentLen)
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * Finish encoding the message and obtain the encoded result.
 * Caller must CFRelease the result. 
 */
OSStatus CMSEncoderCopyEncodedContent(
	CMSEncoderRef		cmsEncoder,
	CFDataRef			*encodedContentOut)	/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);

/*
 * High-level, one-shot encoder function.
 *
 * Inputs (all except for content optional, though at least one 
 *         of {signers, recipients} must be non-NULL)
 * ------------------------------------------------------------
 * signers          : signer identities. Either a SecIdentityRef, or a 
 *                    CFArray of them.
 * recipients       : recipient certificates. Either a SecCertificateRef, 
 *                    or a CFArray of them.
 * eContentType     : contentType for inner EncapsulatedData.
 * detachedContent  : when true, do not include the signed data in the message.
 * signedAttributes : Specifies which standard signed attributes are to be 
 *                    included in the message. 
 * content          : raw content to be signed and/or encrypted.
 *
 * Output
 * ------
 * encodedContent   : the result of the encoding.
 *
 * NOTE: This function is deprecated in Mac OS X 10.7 and later;
 * please use CMSEncodeContent() instead.
 */
OSStatus CMSEncode(
	CFTypeRef			signers,
	CFTypeRef			recipients,
	const CSSM_OID		*eContentType,
	Boolean				detachedContent,
	CMSSignedAttributes	signedAttributes,
	const void			*content,
	size_t				contentLen,
	CFDataRef			*encodedContentOut)	/* RETURNED */
	/* DEPRECATED_IN_MAC_OS_X_VERSION_10_7_AND_LATER; */
    __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_NA);


/*
 * High-level, one-shot encoder function.
 *
 * Inputs (all except for content optional, though at least one 
 *         of {signers, recipients} must be non-NULL)
 * ------------------------------------------------------------
 * signers          : signer identities. Either a SecIdentityRef, or a 
 *                    CFArray of them.
 * recipients       : recipient certificates. Either a SecCertificateRef, 
 *                    or a CFArray of them.
 * eContentTypeOID  : contentType OID for inner EncapsulatedData, e.g.:
 *                    CFSTR("1.2.840.113549.1.7.1")
 * detachedContent  : when true, do not include the signed data in the message.
 * signedAttributes : Specifies which standard signed attributes are to be 
 *                    included in the message. 
 * content          : raw content to be signed and/or encrypted.
 *
 * Output
 * ------
 * encodedContent   : the result of the encoding.
 */
OSStatus CMSEncodeContent(
	CFTypeRef			signers,
	CFTypeRef			recipients,
	CFTypeRef			eContentTypeOID,
	Boolean				detachedContent,
	CMSSignedAttributes	signedAttributes,
	const void			*content,
	size_t				contentLen,
	CFDataRef			*encodedContentOut)	/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);

OSStatus CMSEncoderCopySignerTimestamp(
	CMSEncoderRef		cmsEncoder,
	size_t				signerIndex,        /* usually 0 */
	CFAbsoluteTime      *timestamp)			/* RETURNED */
    __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);

#ifdef __cplusplus
}
#endif

#endif	/* _CMS_ENCODER_H_ */