crypto/dh/dh_ameth.c - third_party/openssl - Git at Google

 /*
  * Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 /*
  * DH low level APIs are deprecated for public use, but still ok for
  * internal use.
  */
 #include "internal/deprecated.h"

 #include <stdio.h>
 #include "internal/cryptlib.h"
 #include <openssl/x509.h>
 #include <openssl/asn1.h>
 #include "dh_local.h"
 #include <openssl/bn.h>
 #include "crypto/asn1.h"
 #include "crypto/dh.h"
 #include "crypto/evp.h"
 #include <openssl/cms.h>
 #include <openssl/core_names.h>
 #include <openssl/param_build.h>
 #include "internal/ffc.h"

 /*
  * i2d/d2i like DH parameter functions which use the appropriate routine for
  * PKCS#3 DH or X9.42 DH.
  */

 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
                    long length)
 {
     DH *dh = NULL;
     int is_dhx = (pkey->ameth == &dhx_asn1_meth);

     if (is_dhx)
         dh = d2i_DHxparams(NULL, pp, length);
     else
         dh = d2i_DHparams(NULL, pp, length);

     if (dh != NULL) {
         DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
         DH_set_flags(dh, is_dhx ? DH_FLAG_TYPE_DHX : DH_FLAG_TYPE_DH);
     }
     return dh;
 }

 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
 {
     if (pkey->ameth == &dhx_asn1_meth)
         return i2d_DHxparams(a, pp);
     return i2d_DHparams(a, pp);
 }

 static void int_dh_free(EVP_PKEY *pkey)
 {
     DH_free(pkey->pkey.dh);
 }

 static int dh_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
 {
     const unsigned char *p, *pm;
     int pklen, pmlen;
     int ptype;
     const void *pval;
     const ASN1_STRING *pstr;
     X509_ALGOR *palg;
     ASN1_INTEGER *public_key = NULL;

     DH *dh = NULL;

     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
         return 0;
     X509_ALGOR_get0(NULL, &ptype, &pval, palg);

     if (ptype != V_ASN1_SEQUENCE) {
         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
         goto err;
     }

     pstr = pval;
     pm = pstr->data;
     pmlen = pstr->length;

     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
         goto err;
     }

     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
         goto err;
     }

     /* We have parameters now set public key */
     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
         goto err;
     }

     ASN1_INTEGER_free(public_key);
     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
     return 1;

  err:
     ASN1_INTEGER_free(public_key);
     DH_free(dh);
     return 0;
 }

 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 {
     DH *dh;
     int ptype;
     unsigned char *penc = NULL;
     int penclen;
     ASN1_STRING *str;
     ASN1_INTEGER *pub_key = NULL;

     dh = pkey->pkey.dh;

     str = ASN1_STRING_new();
     if (str == NULL) {
         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
         goto err;
     }
     str->length = i2d_dhp(pkey, dh, &str->data);
     if (str->length <= 0) {
         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
         goto err;
     }
     ptype = V_ASN1_SEQUENCE;

     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
     if (pub_key == NULL)
         goto err;

     penclen = i2d_ASN1_INTEGER(pub_key, &penc);

     ASN1_INTEGER_free(pub_key);

     if (penclen <= 0) {
         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
         goto err;
     }

     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
                                ptype, str, penc, penclen))
         return 1;

  err:
     OPENSSL_free(penc);
     ASN1_STRING_free(str);

     return 0;
 }

 /*
  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
  * the AlgorithmIdentifier contains the parameters, the private key is
  * explicitly included and the pubkey must be recalculated.
  */

 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 {
     const unsigned char *p, *pm;
     int pklen, pmlen;
     int ptype;
     const void *pval;
     const ASN1_STRING *pstr;
     const X509_ALGOR *palg;
     ASN1_INTEGER *privkey = NULL;
     DH *dh = NULL;

     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
         return 0;

     X509_ALGOR_get0(NULL, &ptype, &pval, palg);

     if (ptype != V_ASN1_SEQUENCE)
         goto decerr;
     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
         goto decerr;

     pstr = pval;
     pm = pstr->data;
     pmlen = pstr->length;
     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
         goto decerr;

     /* We have parameters now set private key */
     if ((dh->priv_key = BN_secure_new()) == NULL
         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
         goto dherr;
     }
     /* Calculate public key, increments dirty_cnt */
     if (!DH_generate_key(dh))
         goto dherr;

     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);

     ASN1_STRING_clear_free(privkey);

     return 1;

  decerr:
     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
  dherr:
     DH_free(dh);
     ASN1_STRING_clear_free(privkey);
     return 0;
 }

 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 {
     ASN1_STRING *params = NULL;
     ASN1_INTEGER *prkey = NULL;
     unsigned char *dp = NULL;
     int dplen;

     params = ASN1_STRING_new();

     if (params == NULL) {
         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
         goto err;
     }

     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
     if (params->length <= 0) {
         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
         goto err;
     }
     params->type = V_ASN1_SEQUENCE;

     /* Get private key into integer */
     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);

     if (prkey == NULL) {
         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
         goto err;
     }

     dplen = i2d_ASN1_INTEGER(prkey, &dp);

     ASN1_STRING_clear_free(prkey);
     prkey = NULL;

     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
                          V_ASN1_SEQUENCE, params, dp, dplen))
         goto err;

     return 1;

  err:
     OPENSSL_free(dp);
     ASN1_STRING_free(params);
     ASN1_STRING_clear_free(prkey);
     return 0;
 }

 static int dh_param_decode(EVP_PKEY *pkey,
                            const unsigned char **pder, int derlen)
 {
     DH *dh;

     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL)
         return 0;
     dh->dirty_cnt++;
     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
     return 1;
 }

 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 {
     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 }

 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 {
     int reason = ERR_R_BUF_LIB;
     const char *ktype = NULL;
     BIGNUM *priv_key, *pub_key;

     if (ptype == 2)
         priv_key = x->priv_key;
     else
         priv_key = NULL;

     if (ptype > 0)
         pub_key = x->pub_key;
     else
         pub_key = NULL;

     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
             || (ptype > 0 && pub_key == NULL)) {
         reason = ERR_R_PASSED_NULL_PARAMETER;
         goto err;
     }

     if (ptype == 2)
         ktype = "DH Private-Key";
     else if (ptype == 1)
         ktype = "DH Public-Key";
     else
         ktype = "DH Parameters";

     if (!BIO_indent(bp, indent, 128)
             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
         goto err;
     indent += 4;

     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
         goto err;
     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
         goto err;

     if (!ffc_params_print(bp, &x->params, indent))
         goto err;

     if (x->length != 0) {
         if (!BIO_indent(bp, indent, 128)
                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
                               (int)x->length) <= 0)
             goto err;
     }

     return 1;

  err:
     DHerr(DH_F_DO_DH_PRINT, reason);
     return 0;
 }

 static int int_dh_size(const EVP_PKEY *pkey)
 {
     return DH_size(pkey->pkey.dh);
 }

 static int dh_bits(const EVP_PKEY *pkey)
 {
     return DH_bits(pkey->pkey.dh);
 }

 static int dh_security_bits(const EVP_PKEY *pkey)
 {
     return DH_security_bits(pkey->pkey.dh);
 }

 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 {
     return ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
                           a->ameth != &dhx_asn1_meth);
 }

 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 {
     if (is_x942 == -1)
         is_x942 = (from->params.q != NULL);
     if (!ffc_params_copy(&to->params, &from->params))
         return 0;
     if (!is_x942)
         to->length = from->length;
     to->dirty_cnt++;
     return 1;
 }

 DH *DHparams_dup(const DH *dh)
 {
     DH *ret;
     ret = DH_new();
     if (ret == NULL)
         return NULL;
     if (!int_dh_param_copy(ret, dh, -1)) {
         DH_free(ret);
         return NULL;
     }
     return ret;
 }

 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 {
     if (to->pkey.dh == NULL) {
         to->pkey.dh = DH_new();
         if (to->pkey.dh == NULL)
             return 0;
     }
     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
                              from->ameth == &dhx_asn1_meth);
 }

 static int dh_missing_parameters(const EVP_PKEY *a)
 {
     return a->pkey.dh == NULL
         || a->pkey.dh->params.p == NULL
         || a->pkey.dh->params.g == NULL;
 }

 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 {
     if (dh_cmp_parameters(a, b) == 0)
         return 0;
     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
         return 0;
     else
         return 1;
 }

 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
                           ASN1_PCTX *ctx)
 {
     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 }

 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
                            ASN1_PCTX *ctx)
 {
     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 }

 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
                             ASN1_PCTX *ctx)
 {
     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 }

 int DHparams_print(BIO *bp, const DH *x)
 {
     return do_dh_print(bp, x, 4, 0);
 }

 #ifndef OPENSSL_NO_CMS
 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 #endif

 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 {
     switch (op) {
     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2, 0, 1);
     default:
         return -2;
     }
 }

 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 {
     switch (op) {
 #ifndef OPENSSL_NO_CMS

     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
         if (arg1 == 1)
             return dh_cms_decrypt(arg2);
         else if (arg1 == 0)
             return dh_cms_encrypt(arg2);
         return -2;

     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
         *(int *)arg2 = CMS_RECIPINFO_AGREE;
         return 1;
 #endif
     default:
         return -2;
     }

 }

 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 {
     DH *dh = pkey->pkey.dh;

     if (dh->pub_key == NULL) {
         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
         return 0;
     }

     return DH_check_pub_key_ex(dh, dh->pub_key);
 }

 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 {
     DH *dh = pkey->pkey.dh;

     return DH_check_ex(dh);
 }

 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 {
     return pkey->pkey.dh->dirty_cnt;
 }

 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
                              EVP_KEYMGMT *to_keymgmt, OPENSSL_CTX *libctx,
                              const char *propq)
 {
     DH *dh = from->pkey.dh;
     OSSL_PARAM_BLD *tmpl;
     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
     const BIGNUM *pub_key = DH_get0_pub_key(dh);
     const BIGNUM *priv_key = DH_get0_priv_key(dh);
     OSSL_PARAM *params = NULL;
     int selection = 0;
     int rv = 0;

     /*
      * If the DH method is foreign, then we can't be sure of anything, and
      * can therefore not export or pretend to export.
      */
     if (dh_get_method(dh) != DH_OpenSSL())
         return 0;

     if (p == NULL || g == NULL)
         return 0;

     tmpl = OSSL_PARAM_BLD_new();
     if (tmpl == NULL)
         return 0;
     if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
         || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
         goto err;
     if (q != NULL) {
         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
             goto err;
     }
     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
     if (pub_key != NULL) {
         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
             goto err;
         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
     }
     if (priv_key != NULL) {
         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
                                     priv_key))
             goto err;
         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
     }

     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
         goto err;

     /* We export, the provider imports */
     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);

     OSSL_PARAM_BLD_free_params(params);
 err:
     OSSL_PARAM_BLD_free(tmpl);
     return rv;
 }

 static int dh_pkey_import_from_type(const OSSL_PARAM params[], void *vpctx,
                                     int type)
 {
     EVP_PKEY_CTX *pctx = vpctx;
     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
     DH *dh = dh_new_ex(pctx->libctx);

     if (dh == NULL) {
         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
         return 0;
     }
     DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
     DH_set_flags(dh, type == EVP_PKEY_DH ? DH_FLAG_TYPE_DH : DH_FLAG_TYPE_DHX);

     if (!dh_ffc_params_fromdata(dh, params)
         || !dh_key_fromdata(dh, params)
         || !EVP_PKEY_assign(pkey, type, dh)) {
         DH_free(dh);
         return 0;
     }
     return 1;
 }

 static int dh_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 {
     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DH);
 }

 static int dhx_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 {
     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DHX);
 }

 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
     EVP_PKEY_DH,
     EVP_PKEY_DH,
     0,

     "DH",
     "OpenSSL PKCS#3 DH method",

     dh_pub_decode,
     dh_pub_encode,
     dh_pub_cmp,
     dh_public_print,

     dh_priv_decode,
     dh_priv_encode,
     dh_private_print,

     int_dh_size,
     dh_bits,
     dh_security_bits,

     dh_param_decode,
     dh_param_encode,
     dh_missing_parameters,
     dh_copy_parameters,
     dh_cmp_parameters,
     dh_param_print,
     0,

     int_dh_free,
     dh_pkey_ctrl,

     0, 0, 0, 0, 0,

     0,
     dh_pkey_public_check,
     dh_pkey_param_check,

     0, 0, 0, 0,

     dh_pkey_dirty_cnt,
     dh_pkey_export_to,
     dh_pkey_import_from,
 };

 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
     EVP_PKEY_DHX,
     EVP_PKEY_DHX,
     0,

     "X9.42 DH",
     "OpenSSL X9.42 DH method",

     dh_pub_decode,
     dh_pub_encode,
     dh_pub_cmp,
     dh_public_print,

     dh_priv_decode,
     dh_priv_encode,
     dh_private_print,

     int_dh_size,
     dh_bits,
     dh_security_bits,

     dh_param_decode,
     dh_param_encode,
     dh_missing_parameters,
     dh_copy_parameters,
     dh_cmp_parameters,
     dh_param_print,
     0,

     int_dh_free,
     dhx_pkey_ctrl,

     0, 0, 0, 0, 0,

     0,
     dh_pkey_public_check,
     dh_pkey_param_check,
     0, 0, 0, 0,
     dh_pkey_dirty_cnt,
     dh_pkey_export_to,
     dhx_pkey_import_from,
 };

 #ifndef OPENSSL_NO_CMS

 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 {
     const ASN1_OBJECT *aoid;
     int atype;
     const void *aval;
     ASN1_INTEGER *public_key = NULL;
     int rv = 0;
     EVP_PKEY *pkpeer = NULL, *pk = NULL;
     DH *dhpeer = NULL;
     const unsigned char *p;
     int plen;

     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
         goto err;
     /* Only absent parameters allowed in RFC XXXX */
     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
         goto err;

     pk = EVP_PKEY_CTX_get0_pkey(pctx);
     if (pk == NULL)
         goto err;
     if (pk->type != EVP_PKEY_DHX)
         goto err;
     /* Get parameters from parent key */
     dhpeer = DHparams_dup(pk->pkey.dh);
     /* We have parameters now set public key */
     plen = ASN1_STRING_length(pubkey);
     p = ASN1_STRING_get0_data(pubkey);
     if (p == NULL || plen == 0)
         goto err;

     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
         goto err;
     }

     /* We have parameters now set public key */
     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
         goto err;
     }

     pkpeer = EVP_PKEY_new();
     if (pkpeer == NULL)
         goto err;
     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
     dhpeer = NULL;
     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
         rv = 1;
  err:
     ASN1_INTEGER_free(public_key);
     EVP_PKEY_free(pkpeer);
     DH_free(dhpeer);
     return rv;
 }

 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 {
     int rv = 0;

     X509_ALGOR *alg, *kekalg = NULL;
     ASN1_OCTET_STRING *ukm;
     const unsigned char *p;
     unsigned char *dukm = NULL;
     size_t dukmlen = 0;
     int keylen, plen;
     const EVP_CIPHER *kekcipher;
     EVP_CIPHER_CTX *kekctx;

     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
         goto err;

     /*
      * For DH we only have one OID permissible. If ever any more get defined
      * we will need something cleverer.
      */
     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
         goto err;
     }

     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
         goto err;

     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
         goto err;

     if (alg->parameter->type != V_ASN1_SEQUENCE)
         goto err;

     p = alg->parameter->value.sequence->data;
     plen = alg->parameter->value.sequence->length;
     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
     if (!kekalg)
         goto err;
     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
     if (!kekctx)
         goto err;
     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
         goto err;
     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
         goto err;
     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
         goto err;

     keylen = EVP_CIPHER_CTX_key_length(kekctx);
     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
         goto err;
     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
         <= 0)
         goto err;

     if (ukm) {
         dukmlen = ASN1_STRING_length(ukm);
         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
         if (!dukm)
             goto err;
     }

     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
         goto err;
     dukm = NULL;

     rv = 1;
  err:
     X509_ALGOR_free(kekalg);
     OPENSSL_free(dukm);
     return rv;
 }

 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 {
     EVP_PKEY_CTX *pctx;

     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);

     if (pctx == NULL)
         return 0;
     /* See if we need to set peer key */
     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
         X509_ALGOR *alg;
         ASN1_BIT_STRING *pubkey;
         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
                                                  NULL, NULL, NULL))
             return 0;
         if (!alg || !pubkey)
             return 0;
         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
             return 0;
         }
     }
     /* Set DH derivation parameters and initialise unwrap context */
     if (!dh_cms_set_shared_info(pctx, ri)) {
         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
         return 0;
     }
     return 1;
 }

 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 {
     EVP_PKEY_CTX *pctx;
     EVP_PKEY *pkey;
     EVP_CIPHER_CTX *ctx;
     int keylen;
     X509_ALGOR *talg, *wrap_alg = NULL;
     const ASN1_OBJECT *aoid;
     ASN1_BIT_STRING *pubkey;
     ASN1_STRING *wrap_str;
     ASN1_OCTET_STRING *ukm;
     unsigned char *penc = NULL, *dukm = NULL;
     int penclen;
     size_t dukmlen = 0;
     int rv = 0;
     int kdf_type, wrap_nid;
     const EVP_MD *kdf_md;

     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
     if (pctx == NULL)
         return 0;
     /* Get ephemeral key */
     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
                                              NULL, NULL, NULL))
         goto err;
     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
     /* Is everything uninitialised? */
     if (aoid == OBJ_nid2obj(NID_undef)) {
         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);

         if (pubk == NULL)
             goto err;
         /* Set the key */

         penclen = i2d_ASN1_INTEGER(pubk, &penc);
         ASN1_INTEGER_free(pubk);
         if (penclen <= 0)
             goto err;
         ASN1_STRING_set0(pubkey, penc, penclen);
         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;

         penc = NULL;
         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
                         V_ASN1_UNDEF, NULL);
     }

     /* See if custom parameters set */
     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
     if (kdf_type <= 0)
         goto err;
     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
         goto err;

     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
         kdf_type = EVP_PKEY_DH_KDF_X9_42;
         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
             goto err;
     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
         /* Unknown KDF */
         goto err;
     if (kdf_md == NULL) {
         /* Only SHA1 supported */
         kdf_md = EVP_sha1();
         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
             goto err;
     } else if (EVP_MD_type(kdf_md) != NID_sha1)
         /* Unsupported digest */
         goto err;

     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
         goto err;

     /* Get wrap NID */
     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
     wrap_nid = EVP_CIPHER_CTX_type(ctx);
     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
         goto err;
     keylen = EVP_CIPHER_CTX_key_length(ctx);

     /* Package wrap algorithm in an AlgorithmIdentifier */

     wrap_alg = X509_ALGOR_new();
     if (wrap_alg == NULL)
         goto err;
     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
     wrap_alg->parameter = ASN1_TYPE_new();
     if (wrap_alg->parameter == NULL)
         goto err;
     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
         goto err;
     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
         ASN1_TYPE_free(wrap_alg->parameter);
         wrap_alg->parameter = NULL;
     }

     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
         goto err;

     if (ukm) {
         dukmlen = ASN1_STRING_length(ukm);
         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
         if (!dukm)
             goto err;
     }

     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
         goto err;
     dukm = NULL;

     /*
      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
      * of another AlgorithmIdentifier.
      */
     penc = NULL;
     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
     if (penc == NULL || penclen == 0)
         goto err;
     wrap_str = ASN1_STRING_new();
     if (wrap_str == NULL)
         goto err;
     ASN1_STRING_set0(wrap_str, penc, penclen);
     penc = NULL;
     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
                     V_ASN1_SEQUENCE, wrap_str);

     rv = 1;

  err:
     OPENSSL_free(penc);
     X509_ALGOR_free(wrap_alg);
     OPENSSL_free(dukm);
     return rv;
 }

 #endif
	/*
	* Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	/*
	* DH low level APIs are deprecated for public use, but still ok for
	* internal use.
	*/
	#include "internal/deprecated.h"

	#include <stdio.h>
	#include "internal/cryptlib.h"
	#include <openssl/x509.h>
	#include <openssl/asn1.h>
	#include "dh_local.h"
	#include <openssl/bn.h>
	#include "crypto/asn1.h"
	#include "crypto/dh.h"
	#include "crypto/evp.h"
	#include <openssl/cms.h>
	#include <openssl/core_names.h>
	#include <openssl/param_build.h>
	#include "internal/ffc.h"

	/*
	* i2d/d2i like DH parameter functions which use the appropriate routine for
	* PKCS#3 DH or X9.42 DH.
	*/

	static DH d2i_dhp(const EVP_PKEY pkey, const unsigned char **pp,
	long length)
	{
	DH *dh = NULL;
	int is_dhx = (pkey->ameth == &dhx_asn1_meth);

	if (is_dhx)
	dh = d2i_DHxparams(NULL, pp, length);
	else
	dh = d2i_DHparams(NULL, pp, length);

	if (dh != NULL) {
	DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
	DH_set_flags(dh, is_dhx ? DH_FLAG_TYPE_DHX : DH_FLAG_TYPE_DH);
	}
	return dh;
	}

	static int i2d_dhp(const EVP_PKEY pkey, const DH a, unsigned char **pp)
	{
	if (pkey->ameth == &dhx_asn1_meth)
	return i2d_DHxparams(a, pp);
	return i2d_DHparams(a, pp);
	}

	static void int_dh_free(EVP_PKEY *pkey)
	{
	DH_free(pkey->pkey.dh);
	}

	static int dh_pub_decode(EVP_PKEY pkey, const X509_PUBKEY pubkey)
	{
	const unsigned char p, pm;
	int pklen, pmlen;
	int ptype;
	const void *pval;
	const ASN1_STRING *pstr;
	X509_ALGOR *palg;
	ASN1_INTEGER *public_key = NULL;

	DH *dh = NULL;

	if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
	return 0;
	X509_ALGOR_get0(NULL, &ptype, &pval, palg);

	if (ptype != V_ASN1_SEQUENCE) {
	DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
	goto err;
	}

	pstr = pval;
	pm = pstr->data;
	pmlen = pstr->length;

	if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
	DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
	goto err;
	}

	if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
	DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
	goto err;
	}

	/* We have parameters now set public key */
	if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
	DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
	goto err;
	}

	ASN1_INTEGER_free(public_key);
	EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
	return 1;

	err:
	ASN1_INTEGER_free(public_key);
	DH_free(dh);
	return 0;
	}

	static int dh_pub_encode(X509_PUBKEY pk, const EVP_PKEY pkey)
	{
	DH *dh;
	int ptype;
	unsigned char *penc = NULL;
	int penclen;
	ASN1_STRING *str;
	ASN1_INTEGER *pub_key = NULL;

	dh = pkey->pkey.dh;

	str = ASN1_STRING_new();
	if (str == NULL) {
	DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	str->length = i2d_dhp(pkey, dh, &str->data);
	if (str->length <= 0) {
	DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	ptype = V_ASN1_SEQUENCE;

	pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
	if (pub_key == NULL)
	goto err;

	penclen = i2d_ASN1_INTEGER(pub_key, &penc);

	ASN1_INTEGER_free(pub_key);

	if (penclen <= 0) {
	DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
	goto err;
	}

	if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
	ptype, str, penc, penclen))
	return 1;

	err:
	OPENSSL_free(penc);
	ASN1_STRING_free(str);

	return 0;
	}

	/*
	* PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
	* the AlgorithmIdentifier contains the parameters, the private key is
	* explicitly included and the pubkey must be recalculated.
	*/

	static int dh_priv_decode(EVP_PKEY pkey, const PKCS8_PRIV_KEY_INFO p8)
	{
	const unsigned char p, pm;
	int pklen, pmlen;
	int ptype;
	const void *pval;
	const ASN1_STRING *pstr;
	const X509_ALGOR *palg;
	ASN1_INTEGER *privkey = NULL;
	DH *dh = NULL;

	if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
	return 0;

	X509_ALGOR_get0(NULL, &ptype, &pval, palg);

	if (ptype != V_ASN1_SEQUENCE)
	goto decerr;
	if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
	goto decerr;

	pstr = pval;
	pm = pstr->data;
	pmlen = pstr->length;
	if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
	goto decerr;

	/* We have parameters now set private key */
	if ((dh->priv_key = BN_secure_new()) == NULL
	\|\| !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
	DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
	goto dherr;
	}
	/* Calculate public key, increments dirty_cnt */
	if (!DH_generate_key(dh))
	goto dherr;

	EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);

	ASN1_STRING_clear_free(privkey);

	return 1;

	decerr:
	DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
	dherr:
	DH_free(dh);
	ASN1_STRING_clear_free(privkey);
	return 0;
	}

	static int dh_priv_encode(PKCS8_PRIV_KEY_INFO p8, const EVP_PKEY pkey)
	{
	ASN1_STRING *params = NULL;
	ASN1_INTEGER *prkey = NULL;
	unsigned char *dp = NULL;
	int dplen;

	params = ASN1_STRING_new();

	if (params == NULL) {
	DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
	goto err;
	}

	params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
	if (params->length <= 0) {
	DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	params->type = V_ASN1_SEQUENCE;

	/* Get private key into integer */
	prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);

	if (prkey == NULL) {
	DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
	goto err;
	}

	dplen = i2d_ASN1_INTEGER(prkey, &dp);

	ASN1_STRING_clear_free(prkey);
	prkey = NULL;

	if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
	V_ASN1_SEQUENCE, params, dp, dplen))
	goto err;

	return 1;

	err:
	OPENSSL_free(dp);
	ASN1_STRING_free(params);
	ASN1_STRING_clear_free(prkey);
	return 0;
	}

	static int dh_param_decode(EVP_PKEY *pkey,
	const unsigned char **pder, int derlen)
	{
	DH *dh;

	if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL)
	return 0;
	dh->dirty_cnt++;
	EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
	return 1;
	}

	static int dh_param_encode(const EVP_PKEY pkey, unsigned char *pder)
	{
	return i2d_dhp(pkey, pkey->pkey.dh, pder);
	}

	static int do_dh_print(BIO bp, const DH x, int indent, int ptype)
	{
	int reason = ERR_R_BUF_LIB;
	const char *ktype = NULL;
	BIGNUM priv_key, pub_key;

	if (ptype == 2)
	priv_key = x->priv_key;
	else
	priv_key = NULL;

	if (ptype > 0)
	pub_key = x->pub_key;
	else
	pub_key = NULL;

	if (x->params.p == NULL \|\| (ptype == 2 && priv_key == NULL)
	\|\| (ptype > 0 && pub_key == NULL)) {
	reason = ERR_R_PASSED_NULL_PARAMETER;
	goto err;
	}

	if (ptype == 2)
	ktype = "DH Private-Key";
	else if (ptype == 1)
	ktype = "DH Public-Key";
	else
	ktype = "DH Parameters";

	if (!BIO_indent(bp, indent, 128)
	\|\| BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
	goto err;
	indent += 4;

	if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
	goto err;
	if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
	goto err;

	if (!ffc_params_print(bp, &x->params, indent))
	goto err;

	if (x->length != 0) {
	if (!BIO_indent(bp, indent, 128)
	\|\| BIO_printf(bp, "recommended-private-length: %d bits\n",
	(int)x->length) <= 0)
	goto err;
	}

	return 1;

	err:
	DHerr(DH_F_DO_DH_PRINT, reason);
	return 0;
	}

	static int int_dh_size(const EVP_PKEY *pkey)
	{
	return DH_size(pkey->pkey.dh);
	}

	static int dh_bits(const EVP_PKEY *pkey)
	{
	return DH_bits(pkey->pkey.dh);
	}

	static int dh_security_bits(const EVP_PKEY *pkey)
	{
	return DH_security_bits(pkey->pkey.dh);
	}

	static int dh_cmp_parameters(const EVP_PKEY a, const EVP_PKEY b)
	{
	return ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
	a->ameth != &dhx_asn1_meth);
	}

	static int int_dh_param_copy(DH to, const DH from, int is_x942)
	{
	if (is_x942 == -1)
	is_x942 = (from->params.q != NULL);
	if (!ffc_params_copy(&to->params, &from->params))
	return 0;
	if (!is_x942)
	to->length = from->length;
	to->dirty_cnt++;
	return 1;
	}

	DH DHparams_dup(const DH dh)
	{
	DH *ret;
	ret = DH_new();
	if (ret == NULL)
	return NULL;
	if (!int_dh_param_copy(ret, dh, -1)) {
	DH_free(ret);
	return NULL;
	}
	return ret;
	}

	static int dh_copy_parameters(EVP_PKEY to, const EVP_PKEY from)
	{
	if (to->pkey.dh == NULL) {
	to->pkey.dh = DH_new();
	if (to->pkey.dh == NULL)
	return 0;
	}
	return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
	from->ameth == &dhx_asn1_meth);
	}

	static int dh_missing_parameters(const EVP_PKEY *a)
	{
	return a->pkey.dh == NULL
	\|\| a->pkey.dh->params.p == NULL
	\|\| a->pkey.dh->params.g == NULL;
	}

	static int dh_pub_cmp(const EVP_PKEY a, const EVP_PKEY b)
	{
	if (dh_cmp_parameters(a, b) == 0)
	return 0;
	if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
	return 0;
	else
	return 1;
	}

	static int dh_param_print(BIO bp, const EVP_PKEY pkey, int indent,
	ASN1_PCTX *ctx)
	{
	return do_dh_print(bp, pkey->pkey.dh, indent, 0);
	}

	static int dh_public_print(BIO bp, const EVP_PKEY pkey, int indent,
	ASN1_PCTX *ctx)
	{
	return do_dh_print(bp, pkey->pkey.dh, indent, 1);
	}

	static int dh_private_print(BIO bp, const EVP_PKEY pkey, int indent,
	ASN1_PCTX *ctx)
	{
	return do_dh_print(bp, pkey->pkey.dh, indent, 2);
	}

	int DHparams_print(BIO bp, const DH x)
	{
	return do_dh_print(bp, x, 4, 0);
	}

	#ifndef OPENSSL_NO_CMS
	static int dh_cms_decrypt(CMS_RecipientInfo *ri);
	static int dh_cms_encrypt(CMS_RecipientInfo *ri);
	#endif

	static int dh_pkey_ctrl(EVP_PKEY pkey, int op, long arg1, void arg2)
	{
	switch (op) {
	case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
	return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
	case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
	return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2, 0, 1);
	default:
	return -2;
	}
	}

	static int dhx_pkey_ctrl(EVP_PKEY pkey, int op, long arg1, void arg2)
	{
	switch (op) {
	#ifndef OPENSSL_NO_CMS

	case ASN1_PKEY_CTRL_CMS_ENVELOPE:
	if (arg1 == 1)
	return dh_cms_decrypt(arg2);
	else if (arg1 == 0)
	return dh_cms_encrypt(arg2);
	return -2;

	case ASN1_PKEY_CTRL_CMS_RI_TYPE:
	(int )arg2 = CMS_RECIPINFO_AGREE;
	return 1;
	#endif
	default:
	return -2;
	}

	}

	static int dh_pkey_public_check(const EVP_PKEY *pkey)
	{
	DH *dh = pkey->pkey.dh;

	if (dh->pub_key == NULL) {
	DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
	return 0;
	}

	return DH_check_pub_key_ex(dh, dh->pub_key);
	}

	static int dh_pkey_param_check(const EVP_PKEY *pkey)
	{
	DH *dh = pkey->pkey.dh;

	return DH_check_ex(dh);
	}

	static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
	{
	return pkey->pkey.dh->dirty_cnt;
	}

	static int dh_pkey_export_to(const EVP_PKEY from, void to_keydata,
	EVP_KEYMGMT to_keymgmt, OPENSSL_CTX libctx,
	const char *propq)
	{
	DH *dh = from->pkey.dh;
	OSSL_PARAM_BLD *tmpl;
	const BIGNUM p = DH_get0_p(dh), g = DH_get0_g(dh), *q = DH_get0_q(dh);
	const BIGNUM *pub_key = DH_get0_pub_key(dh);
	const BIGNUM *priv_key = DH_get0_priv_key(dh);
	OSSL_PARAM *params = NULL;
	int selection = 0;
	int rv = 0;

	/*
	* If the DH method is foreign, then we can't be sure of anything, and
	* can therefore not export or pretend to export.
	*/
	if (dh_get_method(dh) != DH_OpenSSL())
	return 0;

	if (p == NULL \|\| g == NULL)
	return 0;

	tmpl = OSSL_PARAM_BLD_new();
	if (tmpl == NULL)
	return 0;
	if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
	\|\| !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
	goto err;
	if (q != NULL) {
	if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
	goto err;
	}
	selection \|= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
	if (pub_key != NULL) {
	if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
	goto err;
	selection \|= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
	}
	if (priv_key != NULL) {
	if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
	priv_key))
	goto err;
	selection \|= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
	}

	if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
	goto err;

	/* We export, the provider imports */
	rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);

	OSSL_PARAM_BLD_free_params(params);
	err:
	OSSL_PARAM_BLD_free(tmpl);
	return rv;
	}

	static int dh_pkey_import_from_type(const OSSL_PARAM params[], void *vpctx,
	int type)
	{
	EVP_PKEY_CTX *pctx = vpctx;
	EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
	DH *dh = dh_new_ex(pctx->libctx);

	if (dh == NULL) {
	ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
	return 0;
	}
	DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
	DH_set_flags(dh, type == EVP_PKEY_DH ? DH_FLAG_TYPE_DH : DH_FLAG_TYPE_DHX);

	if (!dh_ffc_params_fromdata(dh, params)
	\|\| !dh_key_fromdata(dh, params)
	\|\| !EVP_PKEY_assign(pkey, type, dh)) {
	DH_free(dh);
	return 0;
	}
	return 1;
	}

	static int dh_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
	{
	return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DH);
	}

	static int dhx_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
	{
	return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DHX);
	}

	const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
	EVP_PKEY_DH,
	EVP_PKEY_DH,
	0,

	"DH",
	"OpenSSL PKCS#3 DH method",

	dh_pub_decode,
	dh_pub_encode,
	dh_pub_cmp,
	dh_public_print,

	dh_priv_decode,
	dh_priv_encode,
	dh_private_print,

	int_dh_size,
	dh_bits,
	dh_security_bits,

	dh_param_decode,
	dh_param_encode,
	dh_missing_parameters,
	dh_copy_parameters,
	dh_cmp_parameters,
	dh_param_print,
	0,

	int_dh_free,
	dh_pkey_ctrl,

	0, 0, 0, 0, 0,

	0,
	dh_pkey_public_check,
	dh_pkey_param_check,

	0, 0, 0, 0,

	dh_pkey_dirty_cnt,
	dh_pkey_export_to,
	dh_pkey_import_from,
	};

	const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
	EVP_PKEY_DHX,
	EVP_PKEY_DHX,
	0,

	"X9.42 DH",
	"OpenSSL X9.42 DH method",

	dh_pub_decode,
	dh_pub_encode,
	dh_pub_cmp,
	dh_public_print,

	dh_priv_decode,
	dh_priv_encode,
	dh_private_print,

	int_dh_size,
	dh_bits,
	dh_security_bits,

	dh_param_decode,
	dh_param_encode,
	dh_missing_parameters,
	dh_copy_parameters,
	dh_cmp_parameters,
	dh_param_print,
	0,

	int_dh_free,
	dhx_pkey_ctrl,

	0, 0, 0, 0, 0,

	0,
	dh_pkey_public_check,
	dh_pkey_param_check,
	0, 0, 0, 0,
	dh_pkey_dirty_cnt,
	dh_pkey_export_to,
	dhx_pkey_import_from,
	};

	#ifndef OPENSSL_NO_CMS

	static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
	X509_ALGOR alg, ASN1_BIT_STRING pubkey)
	{
	const ASN1_OBJECT *aoid;
	int atype;
	const void *aval;
	ASN1_INTEGER *public_key = NULL;
	int rv = 0;
	EVP_PKEY pkpeer = NULL, pk = NULL;
	DH *dhpeer = NULL;
	const unsigned char *p;
	int plen;

	X509_ALGOR_get0(&aoid, &atype, &aval, alg);
	if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
	goto err;
	/* Only absent parameters allowed in RFC XXXX */
	if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
	goto err;

	pk = EVP_PKEY_CTX_get0_pkey(pctx);
	if (pk == NULL)
	goto err;
	if (pk->type != EVP_PKEY_DHX)
	goto err;
	/* Get parameters from parent key */
	dhpeer = DHparams_dup(pk->pkey.dh);
	/* We have parameters now set public key */
	plen = ASN1_STRING_length(pubkey);
	p = ASN1_STRING_get0_data(pubkey);
	if (p == NULL \|\| plen == 0)
	goto err;

	if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
	DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
	goto err;
	}

	/* We have parameters now set public key */
	if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
	DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
	goto err;
	}

	pkpeer = EVP_PKEY_new();
	if (pkpeer == NULL)
	goto err;
	EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
	dhpeer = NULL;
	if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
	rv = 1;
	err:
	ASN1_INTEGER_free(public_key);
	EVP_PKEY_free(pkpeer);
	DH_free(dhpeer);
	return rv;
	}

	static int dh_cms_set_shared_info(EVP_PKEY_CTX pctx, CMS_RecipientInfo ri)
	{
	int rv = 0;

	X509_ALGOR alg, kekalg = NULL;
	ASN1_OCTET_STRING *ukm;
	const unsigned char *p;
	unsigned char *dukm = NULL;
	size_t dukmlen = 0;
	int keylen, plen;
	const EVP_CIPHER *kekcipher;
	EVP_CIPHER_CTX *kekctx;

	if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
	goto err;

	/*
	* For DH we only have one OID permissible. If ever any more get defined
	* we will need something cleverer.
	*/
	if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
	DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
	goto err;
	}

	if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
	goto err;

	if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
	goto err;

	if (alg->parameter->type != V_ASN1_SEQUENCE)
	goto err;

	p = alg->parameter->value.sequence->data;
	plen = alg->parameter->value.sequence->length;
	kekalg = d2i_X509_ALGOR(NULL, &p, plen);
	if (!kekalg)
	goto err;
	kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
	if (!kekctx)
	goto err;
	kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
	if (!kekcipher \|\| EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
	goto err;
	if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
	goto err;
	if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
	goto err;

	keylen = EVP_CIPHER_CTX_key_length(kekctx);
	if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
	goto err;
	/* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
	if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
	OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
	<= 0)
	goto err;

	if (ukm) {
	dukmlen = ASN1_STRING_length(ukm);
	dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
	if (!dukm)
	goto err;
	}

	if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
	goto err;
	dukm = NULL;

	rv = 1;
	err:
	X509_ALGOR_free(kekalg);
	OPENSSL_free(dukm);
	return rv;
	}

	static int dh_cms_decrypt(CMS_RecipientInfo *ri)
	{
	EVP_PKEY_CTX *pctx;

	pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);

	if (pctx == NULL)
	return 0;
	/* See if we need to set peer key */
	if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
	X509_ALGOR *alg;
	ASN1_BIT_STRING *pubkey;
	if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
	NULL, NULL, NULL))
	return 0;
	if (!alg \|\| !pubkey)
	return 0;
	if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
	DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
	return 0;
	}
	}
	/* Set DH derivation parameters and initialise unwrap context */
	if (!dh_cms_set_shared_info(pctx, ri)) {
	DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
	return 0;
	}
	return 1;
	}

	static int dh_cms_encrypt(CMS_RecipientInfo *ri)
	{
	EVP_PKEY_CTX *pctx;
	EVP_PKEY *pkey;
	EVP_CIPHER_CTX *ctx;
	int keylen;
	X509_ALGOR talg, wrap_alg = NULL;
	const ASN1_OBJECT *aoid;
	ASN1_BIT_STRING *pubkey;
	ASN1_STRING *wrap_str;
	ASN1_OCTET_STRING *ukm;
	unsigned char penc = NULL, dukm = NULL;
	int penclen;
	size_t dukmlen = 0;
	int rv = 0;
	int kdf_type, wrap_nid;
	const EVP_MD *kdf_md;

	pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
	if (pctx == NULL)
	return 0;
	/* Get ephemeral key */
	pkey = EVP_PKEY_CTX_get0_pkey(pctx);
	if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
	NULL, NULL, NULL))
	goto err;
	X509_ALGOR_get0(&aoid, NULL, NULL, talg);
	/* Is everything uninitialised? */
	if (aoid == OBJ_nid2obj(NID_undef)) {
	ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);

	if (pubk == NULL)
	goto err;
	/* Set the key */

	penclen = i2d_ASN1_INTEGER(pubk, &penc);
	ASN1_INTEGER_free(pubk);
	if (penclen <= 0)
	goto err;
	ASN1_STRING_set0(pubkey, penc, penclen);
	pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT \| 0x07);
	pubkey->flags \|= ASN1_STRING_FLAG_BITS_LEFT;

	penc = NULL;
	X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
	V_ASN1_UNDEF, NULL);
	}

	/* See if custom parameters set */
	kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
	if (kdf_type <= 0)
	goto err;
	if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
	goto err;

	if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
	kdf_type = EVP_PKEY_DH_KDF_X9_42;
	if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
	goto err;
	} else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
	/* Unknown KDF */
	goto err;
	if (kdf_md == NULL) {
	/* Only SHA1 supported */
	kdf_md = EVP_sha1();
	if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
	goto err;
	} else if (EVP_MD_type(kdf_md) != NID_sha1)
	/* Unsupported digest */
	goto err;

	if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
	goto err;

	/* Get wrap NID */
	ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
	wrap_nid = EVP_CIPHER_CTX_type(ctx);
	if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
	goto err;
	keylen = EVP_CIPHER_CTX_key_length(ctx);

	/* Package wrap algorithm in an AlgorithmIdentifier */

	wrap_alg = X509_ALGOR_new();
	if (wrap_alg == NULL)
	goto err;
	wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
	wrap_alg->parameter = ASN1_TYPE_new();
	if (wrap_alg->parameter == NULL)
	goto err;
	if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
	goto err;
	if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
	ASN1_TYPE_free(wrap_alg->parameter);
	wrap_alg->parameter = NULL;
	}

	if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
	goto err;

	if (ukm) {
	dukmlen = ASN1_STRING_length(ukm);
	dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
	if (!dukm)
	goto err;
	}

	if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
	goto err;
	dukm = NULL;

	/*
	* Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
	* of another AlgorithmIdentifier.
	*/
	penc = NULL;
	penclen = i2d_X509_ALGOR(wrap_alg, &penc);
	if (penc == NULL \|\| penclen == 0)
	goto err;
	wrap_str = ASN1_STRING_new();
	if (wrap_str == NULL)
	goto err;
	ASN1_STRING_set0(wrap_str, penc, penclen);
	penc = NULL;
	X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
	V_ASN1_SEQUENCE, wrap_str);

	rv = 1;

	err:
	OPENSSL_free(penc);
	X509_ALGOR_free(wrap_alg);
	OPENSSL_free(dukm);
	return rv;
	}

	#endif