+EVP_PKEY_CTX *EVP_PKEY_CTX_dup(EVP_PKEY_CTX *pctx)
+ {
+ EVP_PKEY_CTX *rctx;
+ if (!pctx->pmeth || !pctx->pmeth->copy)
+ return NULL;
+ rctx = OPENSSL_malloc(sizeof(EVP_PKEY_CTX));
+ if (!rctx)
+ return NULL;
+
+ rctx->pmeth = pctx->pmeth;
+
+ if (pctx->pkey)
+ {
+ CRYPTO_add(&pctx->pkey->references,1,CRYPTO_LOCK_EVP_PKEY);
+ rctx->pkey = pctx->pkey;
+ }
+
+ if (pctx->peerkey)
+ {
+ CRYPTO_add(&pctx->peerkey->references,1,CRYPTO_LOCK_EVP_PKEY);
+ rctx->peerkey = pctx->peerkey;
+ }
+
+ rctx->data = NULL;
+ rctx->app_data = NULL;
+ rctx->operation = pctx->operation;
+
+ if (pctx->pmeth->copy(rctx, pctx) > 0)
+ return pctx;
+
+ EVP_PKEY_CTX_free(rctx);
+ return NULL;
+
+ }
+