crypto/ffc/ffc_params.c

   1 /*
   2  * Copyright 2019-2020 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 <string.h> /* memset */
  11 #include "internal/ffc.h"
  12 #ifndef FIPS_MODE
  13 # include <openssl/asn1.h> /* ffc_params_print */
  14 #endif
  15
  16 void ffc_params_init(FFC_PARAMS *params)
  17 {
  18     memset(params, 0, sizeof(*params));
  19     params->pcounter = -1;
  20     params->gindex = FFC_UNVERIFIABLE_GINDEX;
  21 }
  22
  23 void ffc_params_cleanup(FFC_PARAMS *params)
  24 {
  25     BN_free(params->p);
  26     BN_free(params->q);
  27     BN_free(params->g);
  28     BN_free(params->j);
  29     OPENSSL_free(params->seed);
  30     ffc_params_init(params);
  31 }
  32
  33 void ffc_params_set0_pqg(FFC_PARAMS *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
  34 {
  35     if (p != NULL && p != d->p) {
  36         BN_free(d->p);
  37         d->p = p;
  38     }
  39     if (q != NULL && q != d->q) {
  40         BN_free(d->q);
  41         d->q = q;
  42     }
  43     if (g != NULL && g != d->g) {
  44         BN_free(d->g);
  45         d->g = g;
  46     }
  47 }
  48
  49 void ffc_params_get0_pqg(const FFC_PARAMS *d, const BIGNUM **p,
  50                          const BIGNUM **q, const BIGNUM **g)
  51 {
  52     if (p != NULL)
  53         *p = d->p;
  54     if (q != NULL)
  55         *q = d->q;
  56     if (g != NULL)
  57         *g = d->g;
  58 }
  59
  60
  61 /* j is the 'cofactor' that is optionally output for ASN1. */
  62 void ffc_params_set0_j(FFC_PARAMS *d, BIGNUM *j)
  63 {
  64     BN_free(d->j);
  65     d->j = NULL;
  66     if (j != NULL)
  67         d->j = j;
  68 }
  69
  70 int ffc_params_set_validate_params(FFC_PARAMS *params,
  71                                    const unsigned char *seed, size_t seedlen,
  72                                    int counter)
  73 {
  74     if (params == NULL)
  75         return 0;
  76
  77     if (params->seed != NULL)
  78         OPENSSL_free(params->seed);
  79
  80     if (seed != NULL && seedlen > 0) {
  81         params->seed = OPENSSL_memdup(seed, seedlen);
  82         if (params->seed == NULL)
  83             return 0;
  84         params->seedlen = seedlen;
  85     } else {
  86         params->seed = NULL;
  87         params->seedlen = 0;
  88     }
  89     params->pcounter = counter;
  90     return 1;
  91 }
  92
  93 void ffc_params_get_validate_params(const FFC_PARAMS *params,
  94                                     unsigned char **seed, size_t *seedlen,
  95                                     int *pcounter)
  96 {
  97     if (seed != NULL)
  98         *seed = params->seed;
  99     if (seedlen != NULL)
 100         *seedlen = params->seedlen;
 101     if (pcounter != NULL)
 102         *pcounter = params->pcounter;
 103 }
 104
 105 static int ffc_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 106 {
 107     BIGNUM *a;
 108
 109     /*
 110      * If source is read only just copy the pointer, so
 111      * we don't have to reallocate it.
 112      */
 113     if (src == NULL)
 114         a = NULL;
 115     else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
 116              && !BN_get_flags(src, BN_FLG_MALLOCED))
 117         a = (BIGNUM *)src;
 118     else if ((a = BN_dup(src)) == NULL)
 119         return 0;
 120     BN_clear_free(*dst);
 121     *dst = a;
 122     return 1;
 123 }
 124
 125 int ffc_params_copy(FFC_PARAMS *dst, const FFC_PARAMS *src)
 126 {
 127     if (!ffc_bn_cpy(&dst->p, src->p)
 128         || !ffc_bn_cpy(&dst->g, src->g)
 129         || !ffc_bn_cpy(&dst->q, src->q)
 130         || !ffc_bn_cpy(&dst->j, src->j))
 131         return 0;
 132
 133     OPENSSL_free(dst->seed);
 134     dst->seedlen = src->seedlen;
 135     if (src->seed != NULL) {
 136         dst->seed = OPENSSL_memdup(src->seed, src->seedlen);
 137         if  (dst->seed == NULL)
 138             return 0;
 139     } else {
 140         dst->seed = NULL;
 141     }
 142     dst->pcounter = src->pcounter;
 143     return 1;
 144 }
 145
 146 int ffc_params_cmp(const FFC_PARAMS *a, const FFC_PARAMS *b, int ignore_q)
 147 {
 148     return BN_cmp(a->p, b->p) == 0
 149            && BN_cmp(a->g, b->g) == 0
 150            && (ignore_q || BN_cmp(a->q, b->q) == 0); /* Note: q may be NULL */
 151 }
 152
 153 #ifndef FIPS_MODE
 154 int ffc_params_print(BIO *bp, const FFC_PARAMS *ffc, int indent)
 155 {
 156     if (!ASN1_bn_print(bp, "prime P:", ffc->p, NULL, indent))
 157         goto err;
 158     if (!ASN1_bn_print(bp, "generator G:", ffc->g, NULL, indent))
 159         goto err;
 160     if (ffc->q != NULL
 161         && !ASN1_bn_print(bp, "subgroup order Q:", ffc->q, NULL, indent))
 162         goto err;
 163     if (ffc->j != NULL
 164         && !ASN1_bn_print(bp, "subgroup factor:", ffc->j, NULL, indent))
 165         goto err;
 166     if (ffc->seed != NULL) {
 167         size_t i;
 168         BIO_indent(bp, indent, 128);
 169         BIO_puts(bp, "seed:");
 170         for (i = 0; i < ffc->seedlen; i++) {
 171             if ((i % 15) == 0) {
 172                 if (BIO_puts(bp, "\n") <= 0
 173                     || !BIO_indent(bp, indent + 4, 128))
 174                     goto err;
 175             }
 176             if (BIO_printf(bp, "%02x%s", ffc->seed[i],
 177                            ((i + 1) == ffc->seedlen) ? "" : ":") <= 0)
 178                 goto err;
 179         }
 180         if (BIO_write(bp, "\n", 1) <= 0)
 181             return 0;
 182     }
 183     if (ffc->pcounter != -1) {
 184         BIO_indent(bp, indent, 128);
 185         if (BIO_printf(bp, "counter: %d\n", ffc->pcounter) <= 0)
 186             goto err;
 187     }
 188     return 1;
 189 err:
 190     return 0;
 191 }
 192 #endif /* FIPS_MODE */