diff options
Diffstat (limited to 'crypto/ec/ec_lib.c')
-rw-r--r-- | crypto/ec/ec_lib.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/crypto/ec/ec_lib.c b/crypto/ec/ec_lib.c index c00875c..b3ef056 100644 --- a/crypto/ec/ec_lib.c +++ b/crypto/ec/ec_lib.c @@ -470,6 +470,81 @@ int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx) } +int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx) + { + int r = 0; + BIGNUM *a1, *a2, *a3, *b1, *b2, *b3; + BN_CTX *ctx_new = NULL; + + /* compare the field types*/ + if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) != + EC_METHOD_get_field_type(EC_GROUP_method_of(b))) + return 1; + /* compare the curve name (if present) */ + if (EC_GROUP_get_nid(a) && EC_GROUP_get_nid(b) && + EC_GROUP_get_nid(a) == EC_GROUP_get_nid(b)) + return 0; + + if (!ctx) + ctx_new = ctx = BN_CTX_new(); + if (!ctx) + return -1; + + BN_CTX_start(ctx); + a1 = BN_CTX_get(ctx); + a2 = BN_CTX_get(ctx); + a3 = BN_CTX_get(ctx); + b1 = BN_CTX_get(ctx); + b2 = BN_CTX_get(ctx); + b3 = BN_CTX_get(ctx); + if (!b3) + { + BN_CTX_end(ctx); + if (ctx_new) + BN_CTX_free(ctx); + return -1; + } + + /* XXX This approach assumes that the external representation + * of curves over the same field type is the same. + */ + if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) || + !b->meth->group_get_curve(b, b1, b2, b3, ctx)) + r = 1; + + if (r || BN_cmp(a1, b2) || BN_cmp(a2, b2) || BN_cmp(a3, b3)) + r = 1; + + /* XXX EC_POINT_cmp() assumes that the methods are equal */ + if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a), + EC_GROUP_get0_generator(b), ctx)) + r = 1; + + if (!r) + { + /* compare the order and cofactor */ + if (!EC_GROUP_get_order(a, a1, ctx) || + !EC_GROUP_get_order(b, b1, ctx) || + !EC_GROUP_get_cofactor(a, a2, ctx) || + !EC_GROUP_get_cofactor(b, b2, ctx)) + { + BN_CTX_end(ctx); + if (ctx_new) + BN_CTX_free(ctx); + return -1; + } + if (BN_cmp(a1, b1) || BN_cmp(a2, b2)) + r = 1; + } + + BN_CTX_end(ctx); + if (ctx_new) + BN_CTX_free(ctx); + + return r; + } + + /* this has 'package' visibility */ int EC_GROUP_set_extra_data(EC_GROUP *group, void *data, void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *)) |