Add functions returning security bits.
[openssl.git] / crypto / dh / dh_ameth.c
index 0a862b73d2dd37a0faeb7eb34320034b7e46934b..ce1edcb0d92c6a5999a825fd846256a9cbf19f0a 100644 (file)
@@ -1,4 +1,4 @@
-/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
+/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
 /* ====================================================================
 #include <openssl/x509.h>
 #include <openssl/asn1.h>
 #include <openssl/dh.h>
+#include <openssl/bn.h>
+#include "asn1_locl.h"
+#ifndef OPENSSL_NO_CMS
+#include <openssl/cms.h>
+#endif
+
+extern const EVP_PKEY_ASN1_METHOD dhx_asn1_meth;
+
+/* 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)
+       {
+       if (pkey->ameth == &dhx_asn1_meth)
+               return d2i_DHxparams(NULL, pp, length);
+       return d2i_DHparams(NULL, pp, length);
+       }
+
+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, X509_PUBKEY *pubkey)
+       {
+       const unsigned char *p, *pm;
+       int pklen, pmlen;
+       int ptype;
+       void *pval;
+       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)))
+               {
+               DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
+               goto err;
+               }
+
+       if (!(public_key=d2i_ASN1_INTEGER(NULL, &p, pklen)))
+               {
+               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)))
+               {
+               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:
+       if (public_key)
+               ASN1_INTEGER_free(public_key);
+       if (dh)
+               DH_free(dh);
+       return 0;
+
+       }
+
+static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
+       {
+       DH *dh;
+       void *pval = NULL;
+       int ptype;
+       unsigned char *penc = NULL;
+       int penclen;
+       ASN1_STRING *str;
+       ASN1_INTEGER *pub_key = NULL;
+
+       dh=pkey->pkey.dh;
+
+       str = ASN1_STRING_new();
+       str->length = i2d_dhp(pkey, dh, &str->data);
+       if (str->length <= 0)
+               {
+               DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
+               goto err;
+               }
+       pval = str;
+       ptype = V_ASN1_SEQUENCE;
+
+       pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
+       if (!pub_key)
+               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, pval, penc, penclen))
+               return 1;
+
+       err:
+       if (penc)
+               OPENSSL_free(penc);
+       if (pval)
+               ASN1_STRING_free(pval);
+
+       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 explcitly included and the pubkey must be recalculated.
+ */
+       
+static int dh_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
+       {
+       const unsigned char *p, *pm;
+       int pklen, pmlen;
+       int ptype;
+       void *pval;
+       ASN1_STRING *pstr;
+       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)))
+               goto decerr;
+
+
+       pstr = pval;    
+       pm = pstr->data;
+       pmlen = pstr->length;
+       if (!(dh = d2i_dhp(pkey, &pm, pmlen)))
+               goto decerr;
+       /* We have parameters now set private key */
+       if (!(dh->priv_key = ASN1_INTEGER_to_BN(privkey, NULL)))
+               {
+               DHerr(DH_F_DH_PRIV_DECODE,DH_R_BN_ERROR);
+               goto dherr;
+               }
+       /* Calculate public key */
+       if (!DH_generate_key(dh))
+               goto dherr;
+
+       EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
+
+       ASN1_INTEGER_free(privkey);
+
+       return 1;
+
+       decerr:
+       DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
+       dherr:
+       DH_free(dh);
+       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)
+               {
+               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)
+               {
+               DHerr(DH_F_DH_PRIV_ENCODE,DH_R_BN_ERROR);
+               goto err;
+               }
+
+       dplen = i2d_ASN1_INTEGER(prkey, &dp);
+
+       ASN1_INTEGER_free(prkey);
+
+       if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
+                               V_ASN1_SEQUENCE, params, dp, dplen))
+               goto err;
+
+       return 1;
+
+err:
+       if (dp != NULL)
+               OPENSSL_free(dp);
+       if (params != NULL)
+               ASN1_STRING_free(params);
+       if (prkey != NULL)
+               ASN1_INTEGER_free(prkey);
+       return 0;
+}
+
+
+static void update_buflen(const BIGNUM *b, size_t *pbuflen)
+       {
+       size_t i;
+       if (!b)
+               return;
+       if (*pbuflen < (i = (size_t)BN_num_bytes(b)))
+                       *pbuflen = i;
+       }
+
+static int dh_param_decode(EVP_PKEY *pkey,
+                                       const unsigned char **pder, int derlen)
+       {
+       DH *dh;
+       if (!(dh = d2i_dhp(pkey, pder, derlen)))
+               {
+               DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
+               return 0;
+               }
+       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,
+                                               ASN1_PCTX *ctx, int ptype)
+       {
+       unsigned char *m=NULL;
+       int reason=ERR_R_BUF_LIB,ret=0;
+       size_t buf_len=0;
+
+       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;
+
+       update_buflen(x->p, &buf_len);
+
+       if (buf_len == 0)
+               {
+               reason = ERR_R_PASSED_NULL_PARAMETER;
+               goto err;
+               }
+
+       update_buflen(x->g, &buf_len);
+       update_buflen(x->q, &buf_len);
+       update_buflen(x->j, &buf_len);
+       update_buflen(x->counter, &buf_len);
+       update_buflen(pub_key, &buf_len);
+       update_buflen(priv_key, &buf_len);
+
+       if (ptype == 2)
+               ktype = "DH Private-Key";
+       else if (ptype == 1)
+               ktype = "DH Public-Key";
+       else
+               ktype = "DH Parameters";
+
+       m= OPENSSL_malloc(buf_len+10);
+       if (m == NULL)
+               {
+               reason=ERR_R_MALLOC_FAILURE;
+               goto err;
+               }
+
+       BIO_indent(bp, indent, 128);
+       if (BIO_printf(bp,"%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
+               goto err;
+       indent += 4;
+
+       if (!ASN1_bn_print(bp,"private-key:",priv_key,m,indent)) goto err;
+       if (!ASN1_bn_print(bp,"public-key:",pub_key,m,indent)) goto err;
+
+       if (!ASN1_bn_print(bp,"prime:",x->p,m,indent)) goto err;
+       if (!ASN1_bn_print(bp,"generator:",x->g,m,indent)) goto err;
+       if (x->q && !ASN1_bn_print(bp,"subgroup order:",x->q,m,indent)) goto err;
+       if (x->j && !ASN1_bn_print(bp,"subgroup factor:",x->j,m,indent))
+               goto err;
+       if (x->seed)
+               {
+               int i;
+               BIO_indent(bp, indent, 128);
+               BIO_puts(bp, "seed:");
+               for (i=0; i < x->seedlen; i++)
+                       {
+                       if ((i%15) == 0)
+                               {
+                               if(BIO_puts(bp,"\n") <= 0
+                                  || !BIO_indent(bp,indent+4,128))
+                                   goto err;
+                               }
+                       if (BIO_printf(bp,"%02x%s", x->seed[i],
+                                       ((i+1) == x->seedlen)?"":":") <= 0)
+                               goto err;
+                       }
+               if (BIO_write(bp,"\n",1) <= 0) return(0);
+               }
+       if (x->counter && !ASN1_bn_print(bp,"counter:",x->counter,m,indent))
+               goto err;
+       if (x->length != 0)
+               {
+               BIO_indent(bp, indent, 128);
+               if (BIO_printf(bp,"recommended-private-length: %d bits\n",
+                       (int)x->length) <= 0) goto err;
+               }
+
+
+       ret=1;
+       if (0)
+               {
+err:
+               DHerr(DH_F_DO_DH_PRINT,reason);
+               }
+       if (m != NULL) OPENSSL_free(m);
+       return(ret);
+       }
+
+static int int_dh_size(const EVP_PKEY *pkey)
+       {
+       return(DH_size(pkey->pkey.dh));
+       }
+
+static int dh_bits(const EVP_PKEY *pkey)
+       {
+       return BN_num_bits(pkey->pkey.dh->p);
+       }
+
+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)
+       {
+       if (    BN_cmp(a->pkey.dh->p,b->pkey.dh->p) ||
+               BN_cmp(a->pkey.dh->g,b->pkey.dh->g))
+               return 0;
+       else if (a->ameth == &dhx_asn1_meth)
+               {
+               if (BN_cmp(a->pkey.dh->q,b->pkey.dh->q))
+                       return 0;
+               }
+       return 1;
+       }
+
+static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
+       {
+       BIGNUM *a;
+       if (src)
+               {
+               a = BN_dup(src);
+               if (!a)
+                       return 0;
+               }
+       else 
+               a = NULL;
+       if (*dst)
+               BN_free(*dst);
+       *dst = a;
+       return 1;
+       }
+
+static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
+       {
+       if (is_x942 == -1)
+               is_x942 = !!from->q;
+       if (!int_dh_bn_cpy(&to->p, from->p))
+               return 0;
+       if (!int_dh_bn_cpy(&to->g, from->g))
+               return 0;
+       if (is_x942)
+               {
+               if (!int_dh_bn_cpy(&to->q, from->q))
+                       return 0;
+               if (!int_dh_bn_cpy(&to->j, from->j))
+                       return 0;
+               if(to->seed)
+                       {
+                       OPENSSL_free(to->seed);
+                       to->seed = NULL;
+                       to->seedlen = 0;
+                       }
+               if (from->seed)
+                       {
+                       to->seed = BUF_memdup(from->seed, from->seedlen);
+                       if (!to->seed)
+                               return 0;
+                       to->seedlen = from->seedlen;
+                       }
+               }
+       else
+               to->length = from->length;
+       return 1;
+       }
+
+
+DH *DHparams_dup(DH *dh)
+       {
+       DH *ret;
+       ret = DH_new();
+       if (!ret)
+               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)
+       {
+       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)
+       {
+       if (!a->pkey.dh->p || !a->pkey.dh->g)
+               return 1;
+       return 0;
+       }
+
+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, ctx, 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, ctx, 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, ctx, 2);
+       }
+
+int DHparams_print(BIO *bp, const DH *x)
+       {
+       return do_dh_print(bp, x, 4, NULL, 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)
+               {
+#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;
+               }
+
+       }
+
 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = 
        {
        EVP_PKEY_DH,
        EVP_PKEY_DH,
        0,
 
-       0,
-       0,
-       0,
-       0,
+       "DH",
+       "OpenSSL PKCS#3 DH method",
 
-       0,
-       0,
-       0,
+       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,
+       0
+       };
+
+const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = 
+       {
+       EVP_PKEY_DHX,
+       EVP_PKEY_DHX,
        0,
 
-       0,0,0,0,0,0,
+       "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,
-       0
+       dh_pkey_ctrl
        };
+#ifndef OPENSSL_NO_CMS
+
+static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
+                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
+       {
+       ASN1_OBJECT *aoid;
+       int atype;
+       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)
+               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_data(pubkey);
+       if (!p || !plen)
+               goto err;
+
+       if (!(public_key=d2i_ASN1_INTEGER(NULL, &p, plen)))
+               {
+               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)))
+               {
+               DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
+               goto err;
+               }
+
+       pkpeer = EVP_PKEY_new();
+       if (!pkpeer)
+               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:
+       if (public_key)
+               ASN1_INTEGER_free(public_key);
+       if (pkpeer)
+               EVP_PKEY_free(pkpeer);
+       if (dhpeer)
+               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 = BUF_memdup(ASN1_STRING_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:
+       if (kekalg)
+               X509_ALGOR_free(kekalg);
+       if (dukm)
+               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)
+               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;
+       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)
+               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;
+               pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
+               if (!pubk)
+                       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 paraneters 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)
+               goto err;
+       wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
+       wrap_alg->parameter = ASN1_TYPE_new();
+       if (!wrap_alg->parameter)
+               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 = BUF_memdup(ASN1_STRING_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 || !penclen)
+               goto err;
+       wrap_str = ASN1_STRING_new();
+       if (!wrap_str)
+               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:
+       if (penc)
+               OPENSSL_free(penc);
+       if (wrap_alg)
+               X509_ALGOR_free(wrap_alg);
+       return rv;
+       }
+
+#endif