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 <keys/asymmetric-type.h>
  19 #include <crypto/hash_info.h>
  20
  21 enum pkey_algo {
  22         PKEY_ALGO_DSA,
  23         PKEY_ALGO_RSA,
  24         PKEY_ALGO__LAST
  25 };
  26
  27 extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
  28 extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
  29
  30 /* asymmetric key implementation supports only up to SHA224 */
  31 #define PKEY_HASH__LAST         (HASH_ALGO_SHA224 + 1)
  32
  33 enum pkey_id_type {
  34         PKEY_ID_PGP,            /* OpenPGP generated key ID */
  35         PKEY_ID_X509,           /* X.509 arbitrary subjectKeyIdentifier */
  36         PKEY_ID_PKCS7,          /* Signature in PKCS#7 message */
  37         PKEY_ID_TYPE__LAST
  38 };
  39
  40 extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
  41
  42 /*
  43  * Cryptographic data for the public-key subtype of the asymmetric key type.
  44  *
  45  * Note that this may include private part of the key as well as the public
  46  * part.
  47  */
  48 struct public_key {
  49         const struct public_key_algorithm *algo;
  50         u8      capabilities;
  51 #define PKEY_CAN_ENCRYPT        0x01
  52 #define PKEY_CAN_DECRYPT        0x02
  53 #define PKEY_CAN_SIGN           0x04
  54 #define PKEY_CAN_VERIFY         0x08
  55         enum pkey_algo pkey_algo : 8;
  56         enum pkey_id_type id_type : 8;
  57         union {
  58                 MPI     mpi[5];
  59                 struct {
  60                         MPI     p;      /* DSA prime */
  61                         MPI     q;      /* DSA group order */
  62                         MPI     g;      /* DSA group generator */
  63                         MPI     y;      /* DSA public-key value = g^x mod p */
  64                         MPI     x;      /* DSA secret exponent (if present) */
  65                 } dsa;
  66                 struct {
  67                         MPI     n;      /* RSA public modulus */
  68                         MPI     e;      /* RSA public encryption exponent */
  69                         MPI     d;      /* RSA secret encryption exponent (if present) */
  70                         MPI     p;      /* RSA secret prime (if present) */
  71                         MPI     q;      /* RSA secret prime (if present) */
  72                 } rsa;
  73         };
  74 };
  75
  76 extern void public_key_destroy(void *payload);
  77
  78 /*
  79  * Public key cryptography signature data
  80  */
  81 struct public_key_signature {
  82         u8 *digest;
  83         u8 digest_size;                 /* Number of bytes in digest */
  84         u8 nr_mpi;                      /* Occupancy of mpi[] */
  85         enum pkey_algo pkey_algo : 8;
  86         enum hash_algo pkey_hash_algo : 8;
  87         union {
  88                 MPI mpi[2];
  89                 struct {
  90                         MPI s;          /* m^d mod n */
  91                 } rsa;
  92                 struct {
  93                         MPI r;
  94                         MPI s;
  95                 } dsa;
  96         };
  97 };
  98
  99 struct key;
 100 extern int verify_signature(const struct key *key,
 101                             const struct public_key_signature *sig);
 102
 103 struct asymmetric_key_id;
 104 extern struct key *x509_request_asymmetric_key(struct key *keyring,
 105                                                const struct asymmetric_key_id *id,
 106                                                const struct asymmetric_key_id *skid,
 107                                                bool partial);
 108
 109 #endif /* _LINUX_PUBLIC_KEY_H */