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authorArne Schwabe <arne@rfc2549.org>2012-04-16 19:21:14 +0200
committerArne Schwabe <arne@rfc2549.org>2012-04-16 19:21:14 +0200
commit3e4d8f433239c40311037616b1b8833a06651ae0 (patch)
tree98ab7fce0d011d34677b0beb762d389cb5c39199 /openssl/crypto/ec/ec_check.c
Initial import
Diffstat (limited to 'openssl/crypto/ec/ec_check.c')
-rw-r--r--openssl/crypto/ec/ec_check.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/openssl/crypto/ec/ec_check.c b/openssl/crypto/ec/ec_check.c
new file mode 100644
index 00000000..0e316b4b
--- /dev/null
+++ b/openssl/crypto/ec/ec_check.c
@@ -0,0 +1,123 @@
+/* crypto/ec/ec_check.c */
+/* ====================================================================
+ * Copyright (c) 1998-2002 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 "ec_lcl.h"
+#include <openssl/err.h>
+
+int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)
+ {
+ int ret = 0;
+ BIGNUM *order;
+ BN_CTX *new_ctx = NULL;
+ EC_POINT *point = NULL;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ {
+ ECerr(EC_F_EC_GROUP_CHECK, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ }
+ BN_CTX_start(ctx);
+ if ((order = BN_CTX_get(ctx)) == NULL) goto err;
+
+ /* check the discriminant */
+ if (!EC_GROUP_check_discriminant(group, ctx))
+ {
+ ECerr(EC_F_EC_GROUP_CHECK, EC_R_DISCRIMINANT_IS_ZERO);
+ goto err;
+ }
+
+ /* check the generator */
+ if (group->generator == NULL)
+ {
+ ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_GENERATOR);
+ goto err;
+ }
+ if (!EC_POINT_is_on_curve(group, group->generator, ctx))
+ {
+ ECerr(EC_F_EC_GROUP_CHECK, EC_R_POINT_IS_NOT_ON_CURVE);
+ goto err;
+ }
+
+ /* check the order of the generator */
+ if ((point = EC_POINT_new(group)) == NULL) goto err;
+ if (!EC_GROUP_get_order(group, order, ctx)) goto err;
+ if (BN_is_zero(order))
+ {
+ ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_ORDER);
+ goto err;
+ }
+
+ if (!EC_POINT_mul(group, point, order, NULL, NULL, ctx)) goto err;
+ if (!EC_POINT_is_at_infinity(group, point))
+ {
+ ECerr(EC_F_EC_GROUP_CHECK, EC_R_INVALID_GROUP_ORDER);
+ goto err;
+ }
+
+ ret = 1;
+
+err:
+ if (ctx != NULL)
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ if (point)
+ EC_POINT_free(point);
+ return ret;
+ }