drivers/s390/crypto/zcrypt_cca_key.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  *  Copyright IBM Corp. 2001, 2006
   4  *  Author(s): Robert Burroughs
   5  *             Eric Rossman (edrossma@us.ibm.com)
   6  *
   7  *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
   8  *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
   9  */
  10
  11 #ifndef _ZCRYPT_CCA_KEY_H_
  12 #define _ZCRYPT_CCA_KEY_H_
  13
  14 struct T6_keyBlock_hdr {
  15         unsigned short blen;
  16         unsigned short ulen;
  17         unsigned short flags;
  18 };
  19
  20 /**
  21  * mapping for the cca private ME key token.
  22  * Three parts of interest here: the header, the private section and
  23  * the public section.
  24  *
  25  * mapping for the cca key token header
  26  */
  27 struct cca_token_hdr {
  28         unsigned char  token_identifier;
  29         unsigned char  version;
  30         unsigned short token_length;
  31         unsigned char  reserved[4];
  32 } __packed;
  33
  34 #define CCA_TKN_HDR_ID_EXT 0x1E
  35
  36 #define CCA_PVT_USAGE_ALL 0x80
  37
  38 /**
  39  * mapping for the cca public section
  40  * In a private key, the modulus doesn't appear in the public
  41  * section. So, an arbitrary public exponent of 0x010001 will be
  42  * used, for a section length of 0x0F always.
  43  */
  44 struct cca_public_sec {
  45         unsigned char  section_identifier;
  46         unsigned char  version;
  47         unsigned short section_length;
  48         unsigned char  reserved[2];
  49         unsigned short exponent_len;
  50         unsigned short modulus_bit_len;
  51         unsigned short modulus_byte_len;    /* In a private key, this is 0 */
  52 } __packed;
  53
  54 /**
  55  * mapping for the cca private CRT key 'token'
  56  * The first three parts (the only parts considered in this release)
  57  * are: the header, the private section and the public section.
  58  * The header and public section are the same as for the
  59  * struct cca_private_ext_ME
  60  *
  61  * Following the structure are the quantities p, q, dp, dq, u, pad,
  62  * and modulus, in that order, where pad_len is the modulo 8
  63  * complement of the residue modulo 8 of the sum of
  64  * (p_len + q_len + dp_len + dq_len + u_len).
  65  */
  66 struct cca_pvt_ext_CRT_sec {
  67         unsigned char  section_identifier;
  68         unsigned char  version;
  69         unsigned short section_length;
  70         unsigned char  private_key_hash[20];
  71         unsigned char  reserved1[4];
  72         unsigned char  key_format;
  73         unsigned char  reserved2;
  74         unsigned char  key_name_hash[20];
  75         unsigned char  key_use_flags[4];
  76         unsigned short p_len;
  77         unsigned short q_len;
  78         unsigned short dp_len;
  79         unsigned short dq_len;
  80         unsigned short u_len;
  81         unsigned short mod_len;
  82         unsigned char  reserved3[4];
  83         unsigned short pad_len;
  84         unsigned char  reserved4[52];
  85         unsigned char  confounder[8];
  86 } __packed;
  87
  88 #define CCA_PVT_EXT_CRT_SEC_ID_PVT 0x08
  89 #define CCA_PVT_EXT_CRT_SEC_FMT_CL 0x40
  90
  91 /**
  92  * Set up private key fields of a type6 MEX message. The _pad variant
  93  * strips leading zeroes from the b_key.
  94  * Note that all numerics in the key token are big-endian,
  95  * while the entries in the key block header are little-endian.
  96  *
  97  * @mex: pointer to user input data
  98  * @p: pointer to memory area for the key
  99  *
 100  * Returns the size of the key area or negative errno value.
 101  */
 102 static inline int zcrypt_type6_mex_key_en(struct ica_rsa_modexpo *mex, void *p)
 103 {
 104         static struct cca_token_hdr static_pub_hdr = {
 105                 .token_identifier       =  0x1E,
 106         };
 107         static struct cca_public_sec static_pub_sec = {
 108                 .section_identifier     =  0x04,
 109         };
 110         struct {
 111                 struct T6_keyBlock_hdr t6_hdr;
 112                 struct cca_token_hdr pubHdr;
 113                 struct cca_public_sec pubSec;
 114                 char exponent[0];
 115         } __packed *key = p;
 116         unsigned char *temp;
 117         int i;
 118
 119         /*
 120          * The inputdatalength was a selection criteria in the dispatching
 121          * function zcrypt_rsa_modexpo(). However, do a plausibility check
 122          * here to make sure the following copy_from_user() can't be utilized
 123          * to compromise the system.
 124          */
 125         if (WARN_ON_ONCE(mex->inputdatalength > 512))
 126                 return -EINVAL;
 127
 128         memset(key, 0, sizeof(*key));
 129
 130         key->pubHdr = static_pub_hdr;
 131         key->pubSec = static_pub_sec;
 132
 133         /* key parameter block */
 134         temp = key->exponent;
 135         if (copy_from_user(temp, mex->b_key, mex->inputdatalength))
 136                 return -EFAULT;
 137         /* Strip leading zeroes from b_key. */
 138         for (i = 0; i < mex->inputdatalength; i++)
 139                 if (temp[i])
 140                         break;
 141         if (i >= mex->inputdatalength)
 142                 return -EINVAL;
 143         memmove(temp, temp + i, mex->inputdatalength - i);
 144         temp += mex->inputdatalength - i;
 145         /* modulus */
 146         if (copy_from_user(temp, mex->n_modulus, mex->inputdatalength))
 147                 return -EFAULT;
 148
 149         key->pubSec.modulus_bit_len = 8 * mex->inputdatalength;
 150         key->pubSec.modulus_byte_len = mex->inputdatalength;
 151         key->pubSec.exponent_len = mex->inputdatalength - i;
 152         key->pubSec.section_length = sizeof(key->pubSec) +
 153                                         2*mex->inputdatalength - i;
 154         key->pubHdr.token_length =
 155                 key->pubSec.section_length + sizeof(key->pubHdr);
 156         key->t6_hdr.ulen = key->pubHdr.token_length + 4;
 157         key->t6_hdr.blen = key->pubHdr.token_length + 6;
 158         return sizeof(*key) + 2*mex->inputdatalength - i;
 159 }
 160
 161 /**
 162  * Set up private key fields of a type6 CRT message.
 163  * Note that all numerics in the key token are big-endian,
 164  * while the entries in the key block header are little-endian.
 165  *
 166  * @mex: pointer to user input data
 167  * @p: pointer to memory area for the key
 168  *
 169  * Returns the size of the key area or -EFAULT
 170  */
 171 static inline int zcrypt_type6_crt_key(struct ica_rsa_modexpo_crt *crt, void *p)
 172 {
 173         static struct cca_public_sec static_cca_pub_sec = {
 174                 .section_identifier = 4,
 175                 .section_length = 0x000f,
 176                 .exponent_len = 0x0003,
 177         };
 178         static char pk_exponent[3] = { 0x01, 0x00, 0x01 };
 179         struct {
 180                 struct T6_keyBlock_hdr t6_hdr;
 181                 struct cca_token_hdr token;
 182                 struct cca_pvt_ext_CRT_sec pvt;
 183                 char key_parts[0];
 184         } __packed *key = p;
 185         struct cca_public_sec *pub;
 186         int short_len, long_len, pad_len, key_len, size;
 187
 188         /*
 189          * The inputdatalength was a selection criteria in the dispatching
 190          * function zcrypt_rsa_crt(). However, do a plausibility check
 191          * here to make sure the following copy_from_user() can't be utilized
 192          * to compromise the system.
 193          */
 194         if (WARN_ON_ONCE(crt->inputdatalength > 512))
 195                 return -EINVAL;
 196
 197         memset(key, 0, sizeof(*key));
 198
 199         short_len = (crt->inputdatalength + 1) / 2;
 200         long_len = short_len + 8;
 201         pad_len = -(3*long_len + 2*short_len) & 7;
 202         key_len = 3*long_len + 2*short_len + pad_len + crt->inputdatalength;
 203         size = sizeof(*key) + key_len + sizeof(*pub) + 3;
 204
 205         /* parameter block.key block */
 206         key->t6_hdr.blen = size;
 207         key->t6_hdr.ulen = size - 2;
 208
 209         /* key token header */
 210         key->token.token_identifier = CCA_TKN_HDR_ID_EXT;
 211         key->token.token_length = size - 6;
 212
 213         /* private section */
 214         key->pvt.section_identifier = CCA_PVT_EXT_CRT_SEC_ID_PVT;
 215         key->pvt.section_length = sizeof(key->pvt) + key_len;
 216         key->pvt.key_format = CCA_PVT_EXT_CRT_SEC_FMT_CL;
 217         key->pvt.key_use_flags[0] = CCA_PVT_USAGE_ALL;
 218         key->pvt.p_len = key->pvt.dp_len = key->pvt.u_len = long_len;
 219         key->pvt.q_len = key->pvt.dq_len = short_len;
 220         key->pvt.mod_len = crt->inputdatalength;
 221         key->pvt.pad_len = pad_len;
 222
 223         /* key parts */
 224         if (copy_from_user(key->key_parts, crt->np_prime, long_len) ||
 225             copy_from_user(key->key_parts + long_len,
 226                                         crt->nq_prime, short_len) ||
 227             copy_from_user(key->key_parts + long_len + short_len,
 228                                         crt->bp_key, long_len) ||
 229             copy_from_user(key->key_parts + 2*long_len + short_len,
 230                                         crt->bq_key, short_len) ||
 231             copy_from_user(key->key_parts + 2*long_len + 2*short_len,
 232                                         crt->u_mult_inv, long_len))
 233                 return -EFAULT;
 234         memset(key->key_parts + 3*long_len + 2*short_len + pad_len,
 235                0xff, crt->inputdatalength);
 236         pub = (struct cca_public_sec *)(key->key_parts + key_len);
 237         *pub = static_cca_pub_sec;
 238         pub->modulus_bit_len = 8 * crt->inputdatalength;
 239         /*
 240          * In a private key, the modulus doesn't appear in the public
 241          * section. So, an arbitrary public exponent of 0x010001 will be
 242          * used.
 243          */
 244         memcpy((char *) (pub + 1), pk_exponent, 3);
 245         return size;
 246 }
 247
 248 #endif /* _ZCRYPT_CCA_KEY_H_ */