providers/implementations/keymgmt/rsa_kmgmt.c

   1 /*
   2  * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <openssl/core_numbers.h>
  11 #include <openssl/core_names.h>
  12 #include <openssl/bn.h>
  13 #include <openssl/err.h>
  14 #include <openssl/rsa.h>
  15 #include <openssl/evp.h>
  16 #include <openssl/params.h>
  17 #include <openssl/types.h>
  18 #include "internal/param_build.h"
  19 #include "prov/implementations.h"
  20 #include "prov/providercommon.h"
  21 #include "crypto/rsa.h"
  22
  23 static OSSL_OP_keymgmt_importkey_fn rsa_importkey;
  24 static OSSL_OP_keymgmt_exportkey_fn rsa_exportkey;
  25 static OSSL_OP_keymgmt_get_key_params_fn rsa_get_key_params;
  26
  27 #define RSA_DEFAULT_MD "SHA256"
  28
  29 DEFINE_STACK_OF(BIGNUM)
  30 DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
  31
  32 static int collect_numbers(STACK_OF(BIGNUM) *numbers,
  33                            const OSSL_PARAM params[], const char *key)
  34 {
  35     const OSSL_PARAM *p = NULL;
  36
  37     if (numbers == NULL)
  38         return 0;
  39
  40     for (p = params; (p = OSSL_PARAM_locate_const(p, key)) != NULL; p++) {
  41         BIGNUM *tmp = NULL;
  42
  43         if (!OSSL_PARAM_get_BN(p, &tmp))
  44             return 0;
  45         sk_BIGNUM_push(numbers, tmp);
  46     }
  47
  48     return 1;
  49 }
  50
  51 static int params_to_key(RSA *rsa, const OSSL_PARAM params[])
  52 {
  53     const OSSL_PARAM *param_n, *param_e,  *param_d;
  54     BIGNUM *n = NULL, *e = NULL, *d = NULL;
  55     STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
  56     int is_private = 0;
  57
  58     if (rsa == NULL)
  59         return 0;
  60
  61     param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
  62     param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
  63     param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
  64
  65     if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
  66         || (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
  67         || (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
  68         goto err;
  69
  70     is_private = (d != NULL);
  71
  72     if (!RSA_set0_key(rsa, n, e, d))
  73         goto err;
  74     n = e = d = NULL;
  75
  76     if (is_private) {
  77         if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
  78                              OSSL_PKEY_PARAM_RSA_FACTOR)
  79             || !collect_numbers(exps = sk_BIGNUM_new_null(), params,
  80                                 OSSL_PKEY_PARAM_RSA_EXPONENT)
  81             || !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
  82                                 OSSL_PKEY_PARAM_RSA_COEFFICIENT))
  83             goto err;
  84
  85         /* It's ok if this private key just has n, e and d */
  86         if (sk_BIGNUM_num(factors) != 0
  87             && !rsa_set0_all_params(rsa, factors, exps, coeffs))
  88             goto err;
  89     }
  90
  91     sk_BIGNUM_free(factors);
  92     sk_BIGNUM_free(exps);
  93     sk_BIGNUM_free(coeffs);
  94     return 1;
  95
  96  err:
  97     BN_free(n);
  98     BN_free(e);
  99     BN_free(d);
 100     sk_BIGNUM_pop_free(factors, BN_free);
 101     sk_BIGNUM_pop_free(exps, BN_free);
 102     sk_BIGNUM_pop_free(coeffs, BN_free);
 103     return 0;
 104 }
 105
 106 static int export_numbers(OSSL_PARAM_BLD *tmpl, const char *key,
 107                           STACK_OF(BIGNUM_const) *numbers)
 108 {
 109     int i, nnum;
 110
 111     if (numbers == NULL)
 112         return 0;
 113
 114     nnum = sk_BIGNUM_const_num(numbers);
 115
 116     for (i = 0; i < nnum; i++) {
 117         if (!ossl_param_bld_push_BN(tmpl, key,
 118                                     sk_BIGNUM_const_value(numbers, i)))
 119             return 0;
 120     }
 121
 122     return 1;
 123 }
 124
 125 static int key_to_params(RSA *rsa, OSSL_PARAM_BLD *tmpl)
 126 {
 127     int ret = 0;
 128     const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
 129     STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
 130     STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
 131     STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
 132
 133     if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
 134         goto err;
 135
 136     RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
 137     rsa_get0_all_params(rsa, factors, exps, coeffs);
 138
 139     if (rsa_n != NULL
 140         && !ossl_param_bld_push_BN(tmpl, OSSL_PKEY_PARAM_RSA_N, rsa_n))
 141         goto err;
 142     if (rsa_e != NULL
 143         && !ossl_param_bld_push_BN(tmpl, OSSL_PKEY_PARAM_RSA_E, rsa_e))
 144         goto err;
 145     if (rsa_d != NULL
 146         && !ossl_param_bld_push_BN(tmpl, OSSL_PKEY_PARAM_RSA_D, rsa_d))
 147         goto err;
 148
 149     if (!export_numbers(tmpl, OSSL_PKEY_PARAM_RSA_FACTOR, factors)
 150         || !export_numbers(tmpl, OSSL_PKEY_PARAM_RSA_EXPONENT, exps)
 151         || !export_numbers(tmpl, OSSL_PKEY_PARAM_RSA_COEFFICIENT, coeffs))
 152         goto err;
 153
 154     ret = 1;
 155  err:
 156     sk_BIGNUM_const_free(factors);
 157     sk_BIGNUM_const_free(exps);
 158     sk_BIGNUM_const_free(coeffs);
 159     return ret;
 160 }
 161
 162 static void *rsa_importkey(void *provctx, const OSSL_PARAM params[])
 163 {
 164     RSA *rsa;
 165
 166     if ((rsa = RSA_new()) == NULL
 167         || !params_to_key(rsa, params)) {
 168         RSA_free(rsa);
 169         rsa = NULL;
 170     }
 171     return rsa;
 172 }
 173
 174 static int rsa_exportkey(void *key, OSSL_CALLBACK *param_callback, void *cbarg)
 175 {
 176     RSA *rsa = key;
 177     OSSL_PARAM_BLD tmpl;
 178     OSSL_PARAM *params = NULL;
 179     int ret;
 180
 181     ossl_param_bld_init(&tmpl);
 182     if (rsa == NULL
 183         || !key_to_params(rsa, &tmpl)
 184         || (params = ossl_param_bld_to_param(&tmpl)) == NULL)
 185         return 0;
 186     ret = param_callback(params, cbarg);
 187     ossl_param_bld_free(params);
 188     return ret;
 189 }
 190
 191 /*
 192  * This provider can export everything in an RSA key, so we use the exact
 193  * same type description for export as for import.  Other providers might
 194  * choose to import full keys, but only export the public parts, and will
 195  * therefore have the importkey_types and importkey_types functions return
 196  * different arrays.
 197  */
 198 static const OSSL_PARAM rsa_key_types[] = {
 199     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_N, NULL, 0),
 200     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_E, NULL, 0),
 201     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_D, NULL, 0),
 202     /* We tolerate up to 10 factors... */
 203     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 204     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 205     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 206     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 207     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 208     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 209     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 210     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 211     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 212     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
 213     /* ..., up to 10 CRT exponents... */
 214     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 215     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 216     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 217     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 218     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 219     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 220     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 221     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 222     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 223     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
 224     /* ..., and up to 9 CRT coefficients */
 225     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 226     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 227     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 228     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 229     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 230     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 231     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 232     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 233     OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
 234 };
 235 /*
 236  * We lied about the amount of factors, exponents and coefficients, the
 237  * export and import functions can really deal with an infinite amount
 238  * of these numbers.  However, RSA keys with too many primes are futile,
 239  * so we at least pretend to have some limits.
 240  */
 241
 242 static const OSSL_PARAM *rsa_exportkey_types(void)
 243 {
 244     return rsa_key_types;
 245 }
 246
 247 static const OSSL_PARAM *rsa_importkey_types(void)
 248 {
 249     return rsa_key_types;
 250 }
 251
 252 static int rsa_get_key_params(void *key, OSSL_PARAM params[])
 253 {
 254     RSA *rsa = key;
 255     OSSL_PARAM *p;
 256
 257     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_BITS)) != NULL
 258         && !OSSL_PARAM_set_int(p, RSA_bits(rsa)))
 259         return 0;
 260     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_SECURITY_BITS)) != NULL
 261         && !OSSL_PARAM_set_int(p, RSA_security_bits(rsa)))
 262         return 0;
 263     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_MAX_SIZE)) != NULL
 264         && !OSSL_PARAM_set_int(p, RSA_size(rsa)))
 265         return 0;
 266
 267 # if 0                           /* PSS support pending */
 268     if ((p = OSSL_PARAM_locate(params,
 269                                OSSL_PKEY_PARAM_MANDATORY_DIGEST)) != NULL
 270         && RSA_get0_pss_params(rsa) != NULL) {
 271         const EVP_MD *md, *mgf1md;
 272         int min_saltlen;
 273
 274         if (!rsa_pss_get_param(RSA_get0_pss_params(rsa),
 275                                &md, &mgf1md, &min_saltlen)) {
 276             ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
 277             return 0;
 278         }
 279         if (!OSSL_PARAM_set_utf8_string(p, EVP_MD_name(md)))
 280             return 0;
 281     }
 282 #endif
 283     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_DEFAULT_DIGEST)) != NULL
 284         && RSA_get0_pss_params(rsa) == NULL)
 285         if (!OSSL_PARAM_set_utf8_string(p, RSA_DEFAULT_MD))
 286             return 0;
 287
 288     return 1;
 289 }
 290
 291 const OSSL_DISPATCH rsa_keymgmt_functions[] = {
 292     { OSSL_FUNC_KEYMGMT_IMPORTKEY, (void (*)(void))rsa_importkey },
 293     { OSSL_FUNC_KEYMGMT_IMPORTKEY_TYPES, (void (*)(void))rsa_importkey_types },
 294     { OSSL_FUNC_KEYMGMT_EXPORTKEY, (void (*)(void))rsa_exportkey },
 295     { OSSL_FUNC_KEYMGMT_EXPORTKEY_TYPES, (void (*)(void))rsa_exportkey_types },
 296     { OSSL_FUNC_KEYMGMT_FREEKEY, (void (*)(void))RSA_free },
 297     { OSSL_FUNC_KEYMGMT_GET_KEY_PARAMS,  (void (*) (void))rsa_get_key_params },
 298     { 0, NULL }
 299 };