root/include/crypto/public_key.h

/* Asymmetric public-key algorithm definitions
 *
 * See Documentation/crypto/asymmetric-keys.txt
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#ifndef _LINUX_PUBLIC_KEY_H
#define _LINUX_PUBLIC_KEY_H

#include <linux/mpi.h>
#include <keys/asymmetric-type.h>
#include <crypto/hash_info.h>

enum pkey_algo {
        PKEY_ALGO_DSA,
        PKEY_ALGO_RSA,
        PKEY_ALGO__LAST
};

extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];

/* asymmetric key implementation supports only up to SHA224 */
#define PKEY_HASH__LAST         (HASH_ALGO_SHA224 + 1)

enum pkey_id_type {
        PKEY_ID_PGP,            /* OpenPGP generated key ID */
        PKEY_ID_X509,           /* X.509 arbitrary subjectKeyIdentifier */
        PKEY_ID_TYPE__LAST
};

extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];

/*
 * Cryptographic data for the public-key subtype of the asymmetric key type.
 *
 * Note that this may include private part of the key as well as the public
 * part.
 */
struct public_key {
        const struct public_key_algorithm *algo;
        u8      capabilities;
#define PKEY_CAN_ENCRYPT        0x01
#define PKEY_CAN_DECRYPT        0x02
#define PKEY_CAN_SIGN           0x04
#define PKEY_CAN_VERIFY         0x08
        enum pkey_algo pkey_algo : 8;
        enum pkey_id_type id_type : 8;
        union {
                MPI     mpi[5];
                struct {
                        MPI     p;      /* DSA prime */
                        MPI     q;      /* DSA group order */
                        MPI     g;      /* DSA group generator */
                        MPI     y;      /* DSA public-key value = g^x mod p */
                        MPI     x;      /* DSA secret exponent (if present) */
                } dsa;
                struct {
                        MPI     n;      /* RSA public modulus */
                        MPI     e;      /* RSA public encryption exponent */
                        MPI     d;      /* RSA secret encryption exponent (if present) */
                        MPI     p;      /* RSA secret prime (if present) */
                        MPI     q;      /* RSA secret prime (if present) */
                } rsa;
        };
};

extern void public_key_destroy(void *payload);

/*
 * Public key cryptography signature data
 */
struct public_key_signature {
        u8 *digest;
        u8 digest_size;                 /* Number of bytes in digest */
        u8 nr_mpi;                      /* Occupancy of mpi[] */
        enum pkey_algo pkey_algo : 8;
        enum hash_algo pkey_hash_algo : 8;
        union {
                MPI mpi[2];
                struct {
                        MPI s;          /* m^d mod n */
                } rsa;
                struct {
                        MPI r;
                        MPI s;
                } dsa;
        };
};

struct key;
extern int verify_signature(const struct key *key,
                            const struct public_key_signature *sig);

struct asymmetric_key_id;
extern struct key *x509_request_asymmetric_key(struct key *keyring,
                                               const struct asymmetric_key_id *kid,
                                               bool partial);

#endif /* _LINUX_PUBLIC_KEY_H */