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_PKCS7,          /* Signature in PKCS#7 message */
  36         PKEY_ID_TYPE__LAST
  37 };
  38
  39 extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
  40
  41 /*
  42  * The use to which an asymmetric key is being put.
  43  */
  44 enum key_being_used_for {
  45         VERIFYING_MODULE_SIGNATURE,
  46         VERIFYING_FIRMWARE_SIGNATURE,
  47         VERIFYING_KEXEC_PE_SIGNATURE,
  48         VERIFYING_KEY_SIGNATURE,
  49         VERIFYING_KEY_SELF_SIGNATURE,
  50         VERIFYING_UNSPECIFIED_SIGNATURE,
  51         NR__KEY_BEING_USED_FOR
  52 };
  53 extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
  54
  55 /*
  56  * Cryptographic data for the public-key subtype of the asymmetric key type.
  57  *
  58  * Note that this may include private part of the key as well as the public
  59  * part.
  60  */
  61 struct public_key {
  62         const struct public_key_algorithm *algo;
  63         u8      capabilities;
  64 #define PKEY_CAN_ENCRYPT        0x01
  65 #define PKEY_CAN_DECRYPT        0x02
  66 #define PKEY_CAN_SIGN           0x04
  67 #define PKEY_CAN_VERIFY         0x08
  68         enum pkey_algo pkey_algo : 8;
  69         enum pkey_id_type id_type : 8;
  70         union {
  71                 MPI     mpi[5];
  72                 struct {
  73                         MPI     p;      /* DSA prime */
  74                         MPI     q;      /* DSA group order */
  75                         MPI     g;      /* DSA group generator */
  76                         MPI     y;      /* DSA public-key value = g^x mod p */
  77                         MPI     x;      /* DSA secret exponent (if present) */
  78                 } dsa;
  79                 struct {
  80                         MPI     n;      /* RSA public modulus */
  81                         MPI     e;      /* RSA public encryption exponent */
  82                         MPI     d;      /* RSA secret encryption exponent (if present) */
  83                         MPI     p;      /* RSA secret prime (if present) */
  84                         MPI     q;      /* RSA secret prime (if present) */
  85                 } rsa;
  86         };
  87 };
  88
  89 extern void public_key_destroy(void *payload);
  90
  91 /*
  92  * Public key cryptography signature data
  93  */
  94 struct public_key_signature {
  95         u8 *digest;
  96         u8 digest_size;                 /* Number of bytes in digest */
  97         u8 nr_mpi;                      /* Occupancy of mpi[] */
  98         enum pkey_algo pkey_algo : 8;
  99         enum hash_algo pkey_hash_algo : 8;
 100         union {
 101                 MPI mpi[2];
 102                 struct {
 103                         MPI s;          /* m^d mod n */
 104                 } rsa;
 105                 struct {
 106                         MPI r;
 107                         MPI s;
 108                 } dsa;
 109         };
 110 };
 111
 112 struct key;
 113 extern int verify_signature(const struct key *key,
 114                             const struct public_key_signature *sig);
 115
 116 struct asymmetric_key_id;
 117 extern struct key *x509_request_asymmetric_key(struct key *keyring,
 118                                                const struct asymmetric_key_id *id,
 119                                                const struct asymmetric_key_id *skid,
 120                                                bool partial);
 121
 122 #endif /* _LINUX_PUBLIC_KEY_H */