crypto/rsa_helper.c

   1 /*
   2  * RSA key extract helper
   3  *
   4  * Copyright (c) 2015, Intel Corporation
   5  * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the Free
   9  * Software Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  */
  13 #include <linux/kernel.h>
  14 #include <linux/export.h>
  15 #include <linux/err.h>
  16 #include <linux/fips.h>
  17 #include <crypto/internal/rsa.h>
  18 #include "rsapubkey-asn1.h"
  19 #include "rsaprivkey-asn1.h"
  20
  21 int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
  22               const void *value, size_t vlen)
  23 {
  24         struct rsa_key *key = context;
  25         const u8 *ptr = value;
  26         size_t n_sz = vlen;
  27
  28         /* invalid key provided */
  29         if (!value || !vlen)
  30                 return -EINVAL;
  31
  32         if (fips_enabled) {
  33                 while (n_sz && !*ptr) {
  34                         ptr++;
  35                         n_sz--;
  36                 }
  37
  38                 /* In FIPS mode only allow key size 2K and higher */
  39                 if (n_sz < 256) {
  40                         pr_err("RSA: key size not allowed in FIPS mode\n");
  41                         return -EINVAL;
  42                 }
  43         }
  44
  45         key->n = value;
  46         key->n_sz = vlen;
  47
  48         return 0;
  49 }
  50
  51 int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
  52               const void *value, size_t vlen)
  53 {
  54         struct rsa_key *key = context;
  55
  56         /* invalid key provided */
  57         if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
  58                 return -EINVAL;
  59
  60         key->e = value;
  61         key->e_sz = vlen;
  62
  63         return 0;
  64 }
  65
  66 int rsa_get_d(void *context, size_t hdrlen, unsigned char tag,
  67               const void *value, size_t vlen)
  68 {
  69         struct rsa_key *key = context;
  70
  71         /* invalid key provided */
  72         if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
  73                 return -EINVAL;
  74
  75         key->d = value;
  76         key->d_sz = vlen;
  77
  78         return 0;
  79 }
  80
  81 int rsa_get_p(void *context, size_t hdrlen, unsigned char tag,
  82               const void *value, size_t vlen)
  83 {
  84         struct rsa_key *key = context;
  85
  86         /* invalid key provided */
  87         if (!value || !vlen || vlen > key->n_sz)
  88                 return -EINVAL;
  89
  90         key->p = value;
  91         key->p_sz = vlen;
  92
  93         return 0;
  94 }
  95
  96 int rsa_get_q(void *context, size_t hdrlen, unsigned char tag,
  97               const void *value, size_t vlen)
  98 {
  99         struct rsa_key *key = context;
 100
 101         /* invalid key provided */
 102         if (!value || !vlen || vlen > key->n_sz)
 103                 return -EINVAL;
 104
 105         key->q = value;
 106         key->q_sz = vlen;
 107
 108         return 0;
 109 }
 110
 111 int rsa_get_dp(void *context, size_t hdrlen, unsigned char tag,
 112                const void *value, size_t vlen)
 113 {
 114         struct rsa_key *key = context;
 115
 116         /* invalid key provided */
 117         if (!value || !vlen || vlen > key->n_sz)
 118                 return -EINVAL;
 119
 120         key->dp = value;
 121         key->dp_sz = vlen;
 122
 123         return 0;
 124 }
 125
 126 int rsa_get_dq(void *context, size_t hdrlen, unsigned char tag,
 127                const void *value, size_t vlen)
 128 {
 129         struct rsa_key *key = context;
 130
 131         /* invalid key provided */
 132         if (!value || !vlen || vlen > key->n_sz)
 133                 return -EINVAL;
 134
 135         key->dq = value;
 136         key->dq_sz = vlen;
 137
 138         return 0;
 139 }
 140
 141 int rsa_get_qinv(void *context, size_t hdrlen, unsigned char tag,
 142                  const void *value, size_t vlen)
 143 {
 144         struct rsa_key *key = context;
 145
 146         /* invalid key provided */
 147         if (!value || !vlen || vlen > key->n_sz)
 148                 return -EINVAL;
 149
 150         key->qinv = value;
 151         key->qinv_sz = vlen;
 152
 153         return 0;
 154 }
 155
 156 /**
 157  * rsa_parse_pub_key() - decodes the BER encoded buffer and stores in the
 158  *                       provided struct rsa_key, pointers to the raw key as is,
 159  *                       so that the caller can copy it or MPI parse it, etc.
 160  *
 161  * @rsa_key:    struct rsa_key key representation
 162  * @key:        key in BER format
 163  * @key_len:    length of key
 164  *
 165  * Return:      0 on success or error code in case of error
 166  */
 167 int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key,
 168                       unsigned int key_len)
 169 {
 170         return asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len);
 171 }
 172 EXPORT_SYMBOL_GPL(rsa_parse_pub_key);
 173
 174 /**
 175  * rsa_parse_priv_key() - decodes the BER encoded buffer and stores in the
 176  *                        provided struct rsa_key, pointers to the raw key
 177  *                        as is, so that the caller can copy it or MPI parse it,
 178  *                        etc.
 179  *
 180  * @rsa_key:    struct rsa_key key representation
 181  * @key:        key in BER format
 182  * @key_len:    length of key
 183  *
 184  * Return:      0 on success or error code in case of error
 185  */
 186 int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key,
 187                        unsigned int key_len)
 188 {
 189         return asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len);
 190 }
 191 EXPORT_SYMBOL_GPL(rsa_parse_priv_key);