public_key.h

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/* Asymmetric public-key algorithm definitions
 *
 * See Documentation/crypto/asymmetric-keys.txt
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * 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>

enum pkey_algo {
    PKEY_ALGO_DSA,
    PKEY_ALGO_RSA,
    PKEY_ALGO__LAST
};

extern const char *const pkey_algo[PKEY_ALGO__LAST];

enum pkey_hash_algo {
    PKEY_HASH_MD4,
    PKEY_HASH_MD5,
    PKEY_HASH_SHA1,
    PKEY_HASH_RIPE_MD_160,
    PKEY_HASH_SHA256,
    PKEY_HASH_SHA384,
    PKEY_HASH_SHA512,
    PKEY_HASH_SHA224,
    PKEY_HASH__LAST
};

extern const char *const pkey_hash_algo[PKEY_HASH__LAST];

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[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_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_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);

#endif /* _LINUX_PUBLIC_KEY_H */