cms.h

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#ifndef _IPXE_CMS_H
#define _IPXE_CMS_H

/** @file
 *
 * Cryptographic Message Syntax (PKCS #7)
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <time.h>
#include <ipxe/asn1.h>
#include <ipxe/crypto.h>
#include <ipxe/x509.h>
#include <ipxe/refcnt.h>

struct image;
struct cms_message;

/** A CMS message type */
struct cms_type {
        /** Name */
        const char *name;
        /** Object identifier */
        struct asn1_cursor oid;
        /** Parse content
         *
         * @v cms               CMS message
         * @v raw               ASN.1 cursor
         * @ret rc              Return status code
         */
        int ( * parse ) ( struct cms_message *cms,
                          const struct asn1_cursor *raw );
};

/** CMS participant information */
struct cms_participant {
        /** List of participant information blocks */
        struct list_head list;
        /** Certificate chain */
        struct x509_chain *chain;

        /** Digest algorithm (for signature messages) */
        struct digest_algorithm *digest;
        /** Public-key algorithm */
        struct pubkey_algorithm *pubkey;

        /** Signature or key value */
        struct asn1_cursor value;
};

/** A CMS message */
struct cms_message {
        /** Reference count */
        struct refcnt refcnt;
        /** Raw ASN.1 data */
        struct asn1_cursor *raw;
        /** Message type */
        struct cms_type *type;

        /** List of all certificates (for signature messages) */
        struct x509_chain *certificates;
        /** List of participant information blocks */
        struct list_head participants;

        /** Cipher algorithm */
        struct cipher_algorithm *cipher;
        /** Cipher initialization vector */
        struct asn1_cursor iv;
        /** Cipher authentication tag */
        struct asn1_cursor mac;
};

/**
 * Get reference to CMS message
 *
 * @v cms               CMS message
 * @ret cms             CMS message
 */
static inline __attribute__ (( always_inline )) struct cms_message *
cms_get ( struct cms_message *cms ) {
        ref_get ( &cms->refcnt );
        return cms;
}

/**
 * Drop reference to CMS message
 *
 * @v cms               CMS message
 */
static inline __attribute__ (( always_inline )) void
cms_put ( struct cms_message *cms ) {
        ref_put ( &cms->refcnt );
}

/**
 * Check if CMS message is a signature message
 *
 * @v cms               CMS message
 * @ret is_signature    Message is a signature message
 */
static inline __attribute__ (( always_inline )) int
cms_is_signature ( struct cms_message *cms ) {

        /* CMS signatures include an optional CertificateSet */
        return ( cms->certificates != NULL );
}

/**
 * Check if CMS message is an encrypted message
 *
 * @v cms               CMS message
 * @ret is_encrypted    Message is an encrypted message
 */
static inline __attribute__ (( always_inline )) int
cms_is_encrypted ( struct cms_message *cms ) {

        /* CMS encrypted messages have a cipher algorithm */
        return ( cms->cipher != NULL );
}

extern int cms_message ( struct image *image, struct cms_message **cms );
extern int cms_verify ( struct cms_message *cms, struct image *image,
                        const char *name, time_t time, struct x509_chain *store,
                        struct x509_root *root );
extern int cms_decrypt ( struct cms_message *cms, struct image *image,
                         const char *name, struct private_key *private_key );

#endif /* _IPXE_CMS_H */