Add RFC7919 support to EVP

Reviewed-by: NAndy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4485)

crypto/dh/dh_pmeth.c

@@ -29,6 +29,7 @@ typedef struct {
     /* message digest used for parameter generation */
     const EVP_MD *md;
     int rfc5114_param;
+    int param_nid;
     /* Keygen callback info */
     int gentmp[2];
     /* KDF (if any) to use for DH */
@@ -87,6 +88,7 @@ static int pkey_dh_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
     dctx->use_dsa = sctx->use_dsa;
     dctx->md = sctx->md;
     dctx->rfc5114_param = sctx->rfc5114_param;
+    dctx->param_nid = sctx->param_nid;
 
     dctx->kdf_type = sctx->kdf_type;
     dctx->kdf_oid = OBJ_dup(sctx->kdf_oid);
@@ -137,11 +139,17 @@ static int pkey_dh_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
         return 1;
 
     case EVP_PKEY_CTRL_DH_RFC5114:
-        if (p1 < 1 || p1 > 3)
+        if (p1 < 1 || p1 > 3 || dctx->param_nid != NID_undef)
             return -2;
         dctx->rfc5114_param = p1;
         return 1;
 
+    case EVP_PKEY_CTRL_DH_NID:
+        if (p1 <= 0 || dctx->rfc5114_param != 0)
+            return -2;
+        dctx->param_nid = p1;
+        return 1;
+
     case EVP_PKEY_CTRL_PEER_KEY:
         /* Default behaviour is OK */
         return 1;
@@ -221,6 +229,17 @@ static int pkey_dh_ctrl_str(EVP_PKEY_CTX *ctx,
         dctx->rfc5114_param = len;
         return 1;
     }
+    if (strcmp(type, "dh_param") == 0) {
+        DH_PKEY_CTX *dctx = ctx->data;
+        int nid = OBJ_sn2nid(value);
+
+        if (nid == NID_undef) {
+            DHerr(DH_F_PKEY_DH_CTRL_STR, DH_R_INVALID_PARAMETER_NAME);
+            return -2;
+        }
+        dctx->param_nid = nid;
+        return 1;
+    }
     if (strcmp(type, "dh_paramgen_generator") == 0) {
         int len;
         len = atoi(value);
@@ -320,6 +339,13 @@ static int pkey_dh_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
         return 1;
     }
 
+    if (dctx->param_nid != 0) {
+        if ((dh = DH_new_by_nid(dctx->param_nid)) == NULL)
+            return 0;
+        EVP_PKEY_assign(pkey, EVP_PKEY_DH, dh);
+        return 1;
+    }
+
     if (ctx->pkey_gencb) {
         pcb = BN_GENCB_new();
         if (pcb == NULL)
@@ -359,17 +385,22 @@ static int pkey_dh_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
 
 static int pkey_dh_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
 {
+    DH_PKEY_CTX *dctx = ctx->data;
     DH *dh = NULL;
-    if (ctx->pkey == NULL) {
+
+    if (ctx->pkey == NULL && dctx->param_nid == 0) {
         DHerr(DH_F_PKEY_DH_KEYGEN, DH_R_NO_PARAMETERS_SET);
         return 0;
     }
-    dh = DH_new();
+    if (dctx->param_nid != 0)
+        dh = DH_new_by_nid(dctx->param_nid);
+    else
+        dh = DH_new();
     if (dh == NULL)
         return 0;
     EVP_PKEY_assign(pkey, ctx->pmeth->pkey_id, dh);
     /* Note: if error return, pkey is freed by parent routine */
-    if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
+    if (ctx->pkey != NULL && !EVP_PKEY_copy_parameters(pkey, ctx->pkey))
         return 0;
     return DH_generate_key(pkey->pkey.dh);
 }

include/openssl/dh.h

@@ -242,6 +242,11 @@ int DH_meth_set_generate_params(DH_METHOD *dhm,
         EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DHX, EVP_PKEY_OP_PARAMGEN, \
                         EVP_PKEY_CTRL_DH_RFC5114, gen, NULL)
 
+# define EVP_PKEY_CTX_set_dh_nid(ctx, nid) \
+        EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, \
+                        EVP_PKEY_OP_PARAMGEN | EVP_PKEY_OP_KEYGEN, \
+                        EVP_PKEY_CTRL_DH_NID, nid, NULL)
+
 # define EVP_PKEY_CTX_set_dh_kdf_type(ctx, kdf) \
         EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DHX, \
                                 EVP_PKEY_OP_DERIVE, \
@@ -306,6 +311,7 @@ int DH_meth_set_generate_params(DH_METHOD *dhm,
 # define EVP_PKEY_CTRL_GET_DH_KDF_UKM            (EVP_PKEY_ALG_CTRL + 12)
 # define EVP_PKEY_CTRL_DH_KDF_OID                (EVP_PKEY_ALG_CTRL + 13)
 # define EVP_PKEY_CTRL_GET_DH_KDF_OID            (EVP_PKEY_ALG_CTRL + 14)
+# define EVP_PKEY_CTRL_DH_NID                    (EVP_PKEY_ALG_CTRL + 15)
 
 /* KDF types */
 # define EVP_PKEY_DH_KDF_NONE                            1