diff options
Diffstat (limited to 'openssl/crypto/ec/ec_check.c')
| -rw-r--r-- | openssl/crypto/ec/ec_check.c | 123 |
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 000000000..0e316b4b3 --- /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; + } |