move ECDH implementation to crypto/ec

Reviewed-by: Richard Levitte <levitte@openssl.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/crypto/ec/ecdh_ossl.c b/crypto/ec/ecdh_ossl.c
new file mode 100644
index 0000000000..ba66bd5af2
--- /dev/null
+++ b/crypto/ec/ecdh_ossl.c
@@ -0,0 +1,211 @@
+/* crypto/ecdh/ech_ossl.c */
+/* ====================================================================
+ * 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 <string.h>
+#include <limits.h>
+
+#include "internal/cryptlib.h"
+
+#include "ech_locl.h"
+#include <openssl/err.h>
+#include <openssl/sha.h>
+#include <openssl/obj_mac.h>
+#include <openssl/bn.h>
+
+static int ecdh_compute_key(void *out, size_t len, const EC_POINT *pub_key,
+                            EC_KEY *ecdh,
+                            void *(*KDF) (const void *in, size_t inlen,
+                                          void *out, size_t *outlen));
+
+static ECDH_METHOD openssl_ecdh_meth = {
+    "OpenSSL ECDH method",
+    ecdh_compute_key,
+    ECDH_FLAG_FIPS_METHOD,      /* flags */
+    NULL                        /* app_data */
+};
+
+const ECDH_METHOD *ECDH_OpenSSL(void)
+{
+    return &openssl_ecdh_meth;
+}
+
+/*-
+ * This implementation is based on the following primitives in the IEEE 1363 standard:
+ *  - ECKAS-DH1
+ *  - ECSVDP-DH
+ * Finally an optional KDF is applied.
+ */
+static 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;
+    EC_POINT *tmp = NULL;
+    BIGNUM *x = NULL, *y = NULL;
+    const BIGNUM *priv_key;
+    const EC_GROUP *group;
+    int ret = -1;
+    size_t buflen, len;
+    unsigned char *buf = NULL;
+
+    if (outlen > INT_MAX) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE); /* sort of,
+                                                                 * anyway */
+        return -1;
+    }
+
+    if ((ctx = BN_CTX_new()) == NULL)
+        goto err;
+    BN_CTX_start(ctx);
+    x = BN_CTX_get(ctx);
+    y = BN_CTX_get(ctx);
+
+    priv_key = EC_KEY_get0_private_key(ecdh);
+    if (priv_key == NULL) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_NO_PRIVATE_VALUE);
+        goto err;
+    }
+
+    group = EC_KEY_get0_group(ecdh);
+
+    if (EC_KEY_get_flags(ecdh) & EC_FLAG_COFACTOR_ECDH) {
+        if (!EC_GROUP_get_cofactor(group, x, ctx) ||
+            !BN_mul(x, x, priv_key, ctx)) {
+            ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+        priv_key = x;
+    }
+
+    if ((tmp = EC_POINT_new(group)) == NULL) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    if (!EC_POINT_mul(group, tmp, NULL, pub_key, priv_key, ctx)) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_POINT_ARITHMETIC_FAILURE);
+        goto err;
+    }
+
+    if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) ==
+        NID_X9_62_prime_field) {
+        if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, y, ctx)) {
+            ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_POINT_ARITHMETIC_FAILURE);
+            goto err;
+        }
+    }
+#ifndef OPENSSL_NO_EC2M
+    else {
+        if (!EC_POINT_get_affine_coordinates_GF2m(group, tmp, x, y, ctx)) {
+            ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_POINT_ARITHMETIC_FAILURE);
+            goto err;
+        }
+    }
+#endif
+
+    buflen = (EC_GROUP_get_degree(group) + 7) / 8;
+    len = BN_num_bytes(x);
+    if (len > buflen) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+    if ((buf = OPENSSL_malloc(buflen)) == NULL) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    memset(buf, 0, buflen - len);
+    if (len != (size_t)BN_bn2bin(x, buf + buflen - len)) {
+        ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_BN_LIB);
+        goto err;
+    }
+
+    if (KDF != 0) {
+        if (KDF(buf, buflen, out, &outlen) == NULL) {
+            ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_KDF_FAILED);
+            goto err;
+        }
+        ret = outlen;
+    } else {
+        /* no KDF, just copy as much as we can */
+        if (outlen > buflen)
+            outlen = buflen;
+        memcpy(out, buf, outlen);
+        ret = outlen;
+    }
+
+ err:
+    EC_POINT_free(tmp);
+    if (ctx)
+        BN_CTX_end(ctx);
+    BN_CTX_free(ctx);
+    OPENSSL_free(buf);
+    return (ret);
+}