1 files changed, 272 insertions, 0 deletions

diff --git a/src/lib/libcrypto/ecdh/ecdh.c b/src/lib/libcrypto/ecdh/ecdh.c
new file mode 100644
index 0000000000..d2de3a09af
--- /dev/null
+++ b/src/lib/libcrypto/ecdh/ecdh.c
@@ -0,0 +1,272 @@
+/* $OpenBSD: ecdh.c,v 1.1 2023/07/05 12:31:14 tb Exp $ */
+/* ====================================================================
+ * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
+ *
+ * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
+ * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
+ * to the OpenSSL project.
+ *
+ * The ECC Code is licensed pursuant to the OpenSSL open source
+ * license provided below.
+ *
+ * The ECDH software is originally written by Douglas Stebila of
+ * Sun Microsystems Laboratories.
+ *
+ */
+/* ====================================================================
+ * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <openssl/opensslconf.h>
+
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/ecdh.h>
+#include <openssl/err.h>
+#include <openssl/evp.h>
+
+#include "ec_local.h"
+
+/*
+ * Key derivation function from X9.63/SECG.
+ */
+
+/* Way more than we will ever need */
+#define ECDH_KDF_MAX    (1 << 30)
+
+int
+ecdh_KDF_X9_63(unsigned char *out, size_t outlen, const unsigned char *Z,
+    size_t Zlen, const unsigned char *sinfo, size_t sinfolen, const EVP_MD *md)
+{
+        EVP_MD_CTX *mctx = NULL;
+        unsigned int i;
+        size_t mdlen;
+        unsigned char ctr[4];
+        int rv = 0;
+
+        if (sinfolen > ECDH_KDF_MAX || outlen > ECDH_KDF_MAX ||
+            Zlen > ECDH_KDF_MAX)
+                return 0;
+        mctx = EVP_MD_CTX_new();
+        if (mctx == NULL)
+                return 0;
+        mdlen = EVP_MD_size(md);
+        for (i = 1;; i++) {
+                unsigned char mtmp[EVP_MAX_MD_SIZE];
+                if (!EVP_DigestInit_ex(mctx, md, NULL))
+                        goto err;
+                ctr[3] = i & 0xFF;
+                ctr[2] = (i >> 8) & 0xFF;
+                ctr[1] = (i >> 16) & 0xFF;
+                ctr[0] = (i >> 24) & 0xFF;
+                if (!EVP_DigestUpdate(mctx, Z, Zlen))
+                        goto err;
+                if (!EVP_DigestUpdate(mctx, ctr, sizeof(ctr)))
+                        goto err;
+                if (!EVP_DigestUpdate(mctx, sinfo, sinfolen))
+                        goto err;
+                if (outlen >= mdlen) {
+                        if (!EVP_DigestFinal(mctx, out, NULL))
+                                goto err;
+                        outlen -= mdlen;
+                        if (outlen == 0)
+                                break;
+                        out += mdlen;
+                } else {
+                        if (!EVP_DigestFinal(mctx, mtmp, NULL))
+                                goto err;
+                        memcpy(out, mtmp, outlen);
+                        explicit_bzero(mtmp, mdlen);
+                        break;
+                }
+        }
+        rv = 1;
+
+ err:
+        EVP_MD_CTX_free(mctx);
+
+        return rv;
+}
+
+/*
+ * Based on the ECKAS-DH1 and ECSVDP-DH primitives in the IEEE 1363 standard.
+ */
+/* XXX - KDF handling moved to ECDH_compute_key().  See OpenSSL e2285d87. */
+int
+ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key, EC_KEY *ecdh,
+    void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
+{
+        BN_CTX *ctx;
+        BIGNUM *cofactor, *x;
+        const BIGNUM *priv_key;
+        const EC_GROUP *group;
+        EC_POINT *point = NULL;
+        unsigned char *buf = NULL;
+        int buflen;
+        int ret = -1;
+
+        if (outlen > INT_MAX) {
+                /* Sort of, anyway. */
+                ECDHerror(ERR_R_MALLOC_FAILURE);
+                return -1;
+        }
+
+        if ((ctx = BN_CTX_new()) == NULL)
+                goto err;
+
+        BN_CTX_start(ctx);
+
+        if ((x = BN_CTX_get(ctx)) == NULL)
+                goto err;
+        if ((cofactor = BN_CTX_get(ctx)) == NULL)
+                goto err;
+
+        if ((group = EC_KEY_get0_group(ecdh)) == NULL)
+                goto err;
+
+        if (!EC_POINT_is_on_curve(group, pub_key, ctx))
+                goto err;
+
+        if ((point = EC_POINT_new(group)) == NULL) {
+                ECDHerror(ERR_R_MALLOC_FAILURE);
+                goto err;
+        }
+
+        if ((priv_key = EC_KEY_get0_private_key(ecdh)) == NULL) {
+                ECDHerror(ECDH_R_NO_PRIVATE_VALUE);
+                goto err;
+        }
+
+        if ((EC_KEY_get_flags(ecdh) & EC_FLAG_COFACTOR_ECDH) != 0) {
+                if (!EC_GROUP_get_cofactor(group, cofactor, NULL)) {
+                        ECDHerror(ERR_R_EC_LIB);
+                        goto err;
+                }
+                if (!BN_mul(cofactor, cofactor, priv_key, ctx)) {
+                        ECDHerror(ERR_R_BN_LIB);
+                        goto err;
+                }
+                priv_key = cofactor;
+        }
+
+        if (!EC_POINT_mul(group, point, NULL, pub_key, priv_key, ctx)) {
+                ECDHerror(ECDH_R_POINT_ARITHMETIC_FAILURE);
+                goto err;
+        }
+
+        if (!EC_POINT_get_affine_coordinates(group, point, x, NULL, ctx)) {
+                ECDHerror(ECDH_R_POINT_ARITHMETIC_FAILURE);
+                goto err;
+        }
+
+        if ((buflen = ECDH_size(ecdh)) < BN_num_bytes(x)) {
+                ECDHerror(ERR_R_INTERNAL_ERROR);
+                goto err;
+        }
+        if (KDF == NULL && outlen < buflen) {
+                /* The resulting key would be truncated. */
+                ECDHerror(ECDH_R_KEY_TRUNCATION);
+                goto err;
+        }
+        if ((buf = malloc(buflen)) == NULL) {
+                ECDHerror(ERR_R_MALLOC_FAILURE);
+                goto err;
+        }
+        if (BN_bn2binpad(x, buf, buflen) != buflen) {
+                ECDHerror(ERR_R_BN_LIB);
+                goto err;
+        }
+
+        if (KDF != NULL) {
+                if (KDF(buf, buflen, out, &outlen) == NULL) {
+                        ECDHerror(ECDH_R_KDF_FAILED);
+                        goto err;
+                }
+        } else {
+                memset(out, 0, outlen);
+                if (outlen > buflen)
+                        outlen = buflen;
+                memcpy(out, buf, outlen);
+        }
+
+        ret = outlen;
+ err:
+        EC_POINT_free(point);
+        BN_CTX_end(ctx);
+        BN_CTX_free(ctx);
+        free(buf);
+
+        return ret;
+}
+
+int
+ECDH_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
+    EC_KEY *eckey,
+    void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
+{
+        if (eckey->meth->compute_key == NULL) {
+                ECerror(EC_R_NOT_IMPLEMENTED);
+                return 0;
+        }
+        return eckey->meth->compute_key(out, outlen, pub_key, eckey, KDF);
+}
+
+int
+ECDH_size(const EC_KEY *d)
+{
+        return (EC_GROUP_get_degree(EC_KEY_get0_group(d)) + 7) / 8;
+}