include/crypto/public_key.h

   1 /* Asymmetric public-key algorithm definitions
   2  *
   3  * See Documentation/crypto/asymmetric-keys.txt
   4  *
   5  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
   6  * Written by David Howells (dhowells@redhat.com)
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public Licence
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the Licence, or (at your option) any later version.
  12  */
  13
  14 #ifndef _LINUX_PUBLIC_KEY_H
  15 #define _LINUX_PUBLIC_KEY_H
  16
  17 #include <linux/mpi.h>
  18 #include <crypto/hash_info.h>
  19
  20 enum pkey_algo {
  21         PKEY_ALGO_DSA,
  22         PKEY_ALGO_RSA,
  23         PKEY_ALGO__LAST
  24 };
  25
  26 extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
  27 extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
  28
  29 /* asymmetric key implementation supports only up to SHA224 */
  30 #define PKEY_HASH__LAST         (HASH_ALGO_SHA224 + 1)
  31
  32 enum pkey_id_type {
  33         PKEY_ID_PGP,            /* OpenPGP generated key ID */
  34         PKEY_ID_X509,           /* X.509 arbitrary subjectKeyIdentifier */
  35         PKEY_ID_TYPE__LAST
  36 };
  37
  38 extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
  39
  40 /*
  41  * Cryptographic data for the public-key subtype of the asymmetric key type.
  42  *
  43  * Note that this may include private part of the key as well as the public
  44  * part.
  45  */
  46 struct public_key {
  47         const struct public_key_algorithm *algo;
  48         u8      capabilities;
  49 #define PKEY_CAN_ENCRYPT        0x01
  50 #define PKEY_CAN_DECRYPT        0x02
  51 #define PKEY_CAN_SIGN           0x04
  52 #define PKEY_CAN_VERIFY         0x08
  53         enum pkey_algo pkey_algo : 8;
  54         enum pkey_id_type id_type : 8;
  55         union {
  56                 MPI     mpi[5];
  57                 struct {
  58                         MPI     p;      /* DSA prime */
  59                         MPI     q;      /* DSA group order */
  60                         MPI     g;      /* DSA group generator */
  61                         MPI     y;      /* DSA public-key value = g^x mod p */
  62                         MPI     x;      /* DSA secret exponent (if present) */
  63                 } dsa;
  64                 struct {
  65                         MPI     n;      /* RSA public modulus */
  66                         MPI     e;      /* RSA public encryption exponent */
  67                         MPI     d;      /* RSA secret encryption exponent (if present) */
  68                         MPI     p;      /* RSA secret prime (if present) */
  69                         MPI     q;      /* RSA secret prime (if present) */
  70                 } rsa;
  71         };
  72 };
  73
  74 extern void public_key_destroy(void *payload);
  75
  76 /*
  77  * Public key cryptography signature data
  78  */
  79 struct public_key_signature {
  80         u8 *digest;
  81         u8 digest_size;                 /* Number of bytes in digest */
  82         u8 nr_mpi;                      /* Occupancy of mpi[] */
  83         enum pkey_algo pkey_algo : 8;
  84         enum hash_algo pkey_hash_algo : 8;
  85         union {
  86                 MPI mpi[2];
  87                 struct {
  88                         MPI s;          /* m^d mod n */
  89                 } rsa;
  90                 struct {
  91                         MPI r;
  92                         MPI s;
  93                 } dsa;
  94         };
  95 };
  96
  97 struct key;
  98 extern int verify_signature(const struct key *key,
  99                             const struct public_key_signature *sig);
 100
 101 extern struct key *x509_request_asymmetric_key(struct key *keyring,
 102                                                const char *issuer,
 103                                                const char *key_id);
 104
 105 #endif /* _LINUX_PUBLIC_KEY_H */