1 /* 2 * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (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 <stdio.h> 11 #include "internal/cryptlib.h" 12 #include <openssl/bn.h> 13 #include "dh_locl.h" 14 #include <openssl/objects.h> 15 #include <openssl/asn1t.h> 16 17 /* Override the default free and new methods */ 18 static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it, 19 void *exarg) 20 { 21 if (operation == ASN1_OP_NEW_PRE) { 22 *pval = (ASN1_VALUE *)DH_new(); 23 if (*pval != NULL) 24 return 2; 25 return 0; 26 } else if (operation == ASN1_OP_FREE_PRE) { 27 DH_free((DH *)*pval); 28 *pval = NULL; 29 return 2; 30 } 31 return 1; 32 } 33 34 ASN1_SEQUENCE_cb(DHparams, dh_cb) = { 35 ASN1_SIMPLE(DH, p, BIGNUM), 36 ASN1_SIMPLE(DH, g, BIGNUM), 37 ASN1_OPT_EMBED(DH, length, ZINT32), 38 } ASN1_SEQUENCE_END_cb(DH, DHparams) 39 40 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams) 41 42 /* 43 * Internal only structures for handling X9.42 DH: this gets translated to or 44 * from a DH structure straight away. 45 */ 46 47 typedef struct { 48 ASN1_BIT_STRING *seed; 49 BIGNUM *counter; 50 } int_dhvparams; 51 52 typedef struct { 53 BIGNUM *p; 54 BIGNUM *q; 55 BIGNUM *g; 56 BIGNUM *j; 57 int_dhvparams *vparams; 58 } int_dhx942_dh; 59 60 ASN1_SEQUENCE(DHvparams) = { 61 ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING), 62 ASN1_SIMPLE(int_dhvparams, counter, BIGNUM) 63 } static_ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams) 64 65 ASN1_SEQUENCE(DHxparams) = { 66 ASN1_SIMPLE(int_dhx942_dh, p, BIGNUM), 67 ASN1_SIMPLE(int_dhx942_dh, g, BIGNUM), 68 ASN1_SIMPLE(int_dhx942_dh, q, BIGNUM), 69 ASN1_OPT(int_dhx942_dh, j, BIGNUM), 70 ASN1_OPT(int_dhx942_dh, vparams, DHvparams), 71 } static_ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams) 72 73 int_dhx942_dh *d2i_int_dhx(int_dhx942_dh **a, 74 const unsigned char **pp, long length); 75 int i2d_int_dhx(const int_dhx942_dh *a, unsigned char **pp); 76 77 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(int_dhx942_dh, DHxparams, int_dhx) 78 79 /* Application public function: read in X9.42 DH parameters into DH structure */ 80 81 DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length) 82 { 83 int_dhx942_dh *dhx = NULL; 84 DH *dh = NULL; 85 dh = DH_new(); 86 if (dh == NULL) 87 return NULL; 88 dhx = d2i_int_dhx(NULL, pp, length); 89 if (dhx == NULL) { 90 DH_free(dh); 91 return NULL; 92 } 93 94 if (a) { 95 DH_free(*a); 96 *a = dh; 97 } 98 99 dh->p = dhx->p; 100 dh->q = dhx->q; 101 dh->g = dhx->g; 102 dh->j = dhx->j; 103 104 if (dhx->vparams) { 105 dh->seed = dhx->vparams->seed->data; 106 dh->seedlen = dhx->vparams->seed->length; 107 dh->counter = dhx->vparams->counter; 108 dhx->vparams->seed->data = NULL; 109 ASN1_BIT_STRING_free(dhx->vparams->seed); 110 OPENSSL_free(dhx->vparams); 111 dhx->vparams = NULL; 112 } 113 114 OPENSSL_free(dhx); 115 return dh; 116 } 117 118 int i2d_DHxparams(const DH *dh, unsigned char **pp) 119 { 120 int_dhx942_dh dhx; 121 int_dhvparams dhv; 122 ASN1_BIT_STRING bs; 123 dhx.p = dh->p; 124 dhx.g = dh->g; 125 dhx.q = dh->q; 126 dhx.j = dh->j; 127 if (dh->counter && dh->seed && dh->seedlen > 0) { 128 bs.flags = ASN1_STRING_FLAG_BITS_LEFT; 129 bs.data = dh->seed; 130 bs.length = dh->seedlen; 131 dhv.seed = &bs; 132 dhv.counter = dh->counter; 133 dhx.vparams = &dhv; 134 } else 135 dhx.vparams = NULL; 136 137 return i2d_int_dhx(&dhx, pp); 138 } 139