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  * The use to which an asymmetric key is being put.
  44  */
  45 enum key_being_used_for {
  46         VERIFYING_MODULE_SIGNATURE,
  47         VERIFYING_FIRMWARE_SIGNATURE,
  48         VERIFYING_KEXEC_PE_SIGNATURE,
  49         VERIFYING_KEY_SIGNATURE,
  50         VERIFYING_KEY_SELF_SIGNATURE,
  51         VERIFYING_UNSPECIFIED_SIGNATURE,
  52         NR__KEY_BEING_USED_FOR
  53 };
  54 extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
  55
  56 /*
  57  * Cryptographic data for the public-key subtype of the asymmetric key type.
  58  *
  59  * Note that this may include private part of the key as well as the public
  60  * part.
  61  */
  62 struct public_key {
  63         const struct public_key_algorithm *algo;
  64         u8      capabilities;
  65 #define PKEY_CAN_ENCRYPT        0x01
  66 #define PKEY_CAN_DECRYPT        0x02
  67 #define PKEY_CAN_SIGN           0x04
  68 #define PKEY_CAN_VERIFY         0x08
  69         enum pkey_algo pkey_algo : 8;
  70         enum pkey_id_type id_type : 8;
  71         union {
  72                 MPI     mpi[5];
  73                 struct {
  74                         MPI     p;      /* DSA prime */
  75                         MPI     q;      /* DSA group order */
  76                         MPI     g;      /* DSA group generator */
  77                         MPI     y;      /* DSA public-key value = g^x mod p */
  78                         MPI     x;      /* DSA secret exponent (if present) */
  79                 } dsa;
  80                 struct {
  81                         MPI     n;      /* RSA public modulus */
  82                         MPI     e;      /* RSA public encryption exponent */
  83                         MPI     d;      /* RSA secret encryption exponent (if present) */
  84                         MPI     p;      /* RSA secret prime (if present) */
  85                         MPI     q;      /* RSA secret prime (if present) */
  86                 } rsa;
  87         };
  88 };
  89
  90 extern void public_key_destroy(void *payload);
  91
  92 /*
  93  * Public key cryptography signature data
  94  */
  95 struct public_key_signature {
  96         u8 *digest;
  97         u8 digest_size;                 /* Number of bytes in digest */
  98         u8 nr_mpi;                      /* Occupancy of mpi[] */
  99         enum pkey_algo pkey_algo : 8;
 100         enum hash_algo pkey_hash_algo : 8;
 101         union {
 102                 MPI mpi[2];
 103                 struct {
 104                         MPI s;          /* m^d mod n */
 105                 } rsa;
 106                 struct {
 107                         MPI r;
 108                         MPI s;
 109                 } dsa;
 110         };
 111 };
 112
 113 struct key;
 114 extern int verify_signature(const struct key *key,
 115                             const struct public_key_signature *sig);
 116
 117 struct asymmetric_key_id;
 118 extern struct key *x509_request_asymmetric_key(struct key *keyring,
 119                                                const struct asymmetric_key_id *id,
 120                                                const struct asymmetric_key_id *skid,
 121                                                bool partial);
 122
 123 #endif /* _LINUX_PUBLIC_KEY_H */