Latest update.

providers/implementations/exchange/build.info

@@ -0,0 +1,8 @@
+# We make separate GOAL variables for each algorithm, to make it easy to
+# switch each to the Legacy provider when needed.
+
+$DH_GOAL=../../libimplementations.a
+
+IF[{- !$disabled{dh} -}]
+  SOURCE[$DH_GOAL]=dh_exch.c
+ENDIF

providers/implementations/exchange/dh_exch.c

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2019 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
+ */
+
+#include <openssl/crypto.h>
+#include <openssl/core_numbers.h>
+#include <openssl/core_names.h>
+#include <openssl/dh.h>
+#include <openssl/params.h>
+#include "prov/implementations.h"
+
+static OSSL_OP_keyexch_newctx_fn dh_newctx;
+static OSSL_OP_keyexch_init_fn dh_init;
+static OSSL_OP_keyexch_set_peer_fn dh_set_peer;
+static OSSL_OP_keyexch_derive_fn dh_derive;
+static OSSL_OP_keyexch_freectx_fn dh_freectx;
+static OSSL_OP_keyexch_dupctx_fn dh_dupctx;
+static OSSL_OP_keyexch_set_ctx_params_fn dh_set_ctx_params;
+static OSSL_OP_keyexch_settable_ctx_params_fn dh_settable_ctx_params;
+
+/*
+ * What's passed as an actual key is defined by the KEYMGMT interface.
+ * We happen to know that our KEYMGMT simply passes DH structures, so
+ * we use that here too.
+ */
+
+typedef struct {
+    DH *dh;
+    DH *dhpeer;
+    unsigned int pad : 1;
+} PROV_DH_CTX;
+
+static void *dh_newctx(void *provctx)
+{
+    return OPENSSL_zalloc(sizeof(PROV_DH_CTX));
+}
+
+static int dh_init(void *vpdhctx, void *vdh)
+{
+    PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
+
+    if (pdhctx == NULL || vdh == NULL || !DH_up_ref(vdh))
+        return 0;
+    DH_free(pdhctx->dh);
+    pdhctx->dh = vdh;
+    return 1;
+}
+
+static int dh_set_peer(void *vpdhctx, void *vdh)
+{
+    PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
+
+    if (pdhctx == NULL || vdh == NULL || !DH_up_ref(vdh))
+        return 0;
+    DH_free(pdhctx->dhpeer);
+    pdhctx->dhpeer = vdh;
+    return 1;
+}
+
+static int dh_derive(void *vpdhctx, unsigned char *secret, size_t *secretlen,
+                     size_t outlen)
+{
+    PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
+    int ret;
+    size_t dhsize;
+    const BIGNUM *pub_key = NULL;
+
+    /* TODO(3.0): Add errors to stack */
+    if (pdhctx->dh == NULL || pdhctx->dhpeer == NULL)
+        return 0;
+
+    dhsize = (size_t)DH_size(pdhctx->dh);
+    if (secret == NULL) {
+        *secretlen = dhsize;
+        return 1;
+    }
+    if (outlen < dhsize)
+        return 0;
+
+    DH_get0_key(pdhctx->dhpeer, &pub_key, NULL);
+    ret = (pdhctx->pad) ? DH_compute_key_padded(secret, pub_key, pdhctx->dh)
+                        : DH_compute_key(secret, pub_key, pdhctx->dh);
+    if (ret <= 0)
+        return 0;
+
+    *secretlen = ret;
+    return 1;
+}
+
+static void dh_freectx(void *vpdhctx)
+{
+    PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
+
+    DH_free(pdhctx->dh);
+    DH_free(pdhctx->dhpeer);
+
+    OPENSSL_free(pdhctx);
+}
+
+static void *dh_dupctx(void *vpdhctx)
+{
+    PROV_DH_CTX *srcctx = (PROV_DH_CTX *)vpdhctx;
+    PROV_DH_CTX *dstctx;
+
+    dstctx = OPENSSL_zalloc(sizeof(*srcctx));
+    if (dstctx == NULL)
+        return NULL;
+
+    *dstctx = *srcctx;
+    if (dstctx->dh != NULL && !DH_up_ref(dstctx->dh)) {
+        OPENSSL_free(dstctx);
+        return NULL;
+    }
+
+    if (dstctx->dhpeer != NULL && !DH_up_ref(dstctx->dhpeer)) {
+        DH_free(dstctx->dh);
+        OPENSSL_free(dstctx);
+        return NULL;
+    }
+
+    return dstctx;
+}
+
+static int dh_set_ctx_params(void *vpdhctx, const OSSL_PARAM params[])
+{
+    PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
+    const OSSL_PARAM *p;
+    unsigned int pad;
+
+    if (pdhctx == NULL || params == NULL)
+        return 0;
+
+    p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_PAD);
+    if (p == NULL || !OSSL_PARAM_get_uint(p, &pad))
+        return 0;
+    pdhctx->pad = pad ? 1 : 0;
+    return 1;
+}
+
+static const OSSL_PARAM known_settable_ctx_params[] = {
+    OSSL_PARAM_int(OSSL_EXCHANGE_PARAM_PAD, NULL),
+    OSSL_PARAM_END
+};
+
+static const OSSL_PARAM *dh_settable_ctx_params(void)
+{
+    return known_settable_ctx_params;
+}
+
+const OSSL_DISPATCH dh_keyexch_functions[] = {
+    { OSSL_FUNC_KEYEXCH_NEWCTX, (void (*)(void))dh_newctx },
+    { OSSL_FUNC_KEYEXCH_INIT, (void (*)(void))dh_init },
+    { OSSL_FUNC_KEYEXCH_DERIVE, (void (*)(void))dh_derive },
+    { OSSL_FUNC_KEYEXCH_SET_PEER, (void (*)(void))dh_set_peer },
+    { OSSL_FUNC_KEYEXCH_FREECTX, (void (*)(void))dh_freectx },
+    { OSSL_FUNC_KEYEXCH_DUPCTX, (void (*)(void))dh_dupctx },
+    { OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS, (void (*)(void))dh_set_ctx_params },
+    { OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS,
+      (void (*)(void))dh_settable_ctx_params },
+    { 0, NULL }
+};