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-rw-r--r--crypto/ec/ec2_oct.c620
1 files changed, 308 insertions, 312 deletions
diff --git a/crypto/ec/ec2_oct.c b/crypto/ec/ec2_oct.c
index f1d75e5ddf66..c245d886dad1 100644
--- a/crypto/ec/ec2_oct.c
+++ b/crypto/ec/ec2_oct.c
@@ -21,7 +21,7 @@
* are met:
*
* 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
+ * 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
@@ -73,12 +73,13 @@
#ifndef OPENSSL_NO_EC2M
-/* Calculates and sets the affine coordinates of an EC_POINT from the given
- * compressed coordinates. Uses algorithm 2.3.4 of SEC 1.
+/*-
+ * Calculates and sets the affine coordinates of an EC_POINT from the given
+ * compressed coordinates. Uses algorithm 2.3.4 of SEC 1.
* Note that the simple implementation only uses affine coordinates.
*
* The method is from the following publication:
- *
+ *
* Harper, Menezes, Vanstone:
* "Public-Key Cryptosystems with Very Small Key Lengths",
* EUROCRYPT '92, Springer-Verlag LNCS 658,
@@ -88,320 +89,315 @@
* the same method, but claim no priority date earlier than July 29, 1994
* (and additionally fail to cite the EUROCRYPT '92 publication as prior art).
*/
-int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
- const BIGNUM *x_, int y_bit, BN_CTX *ctx)
- {
- BN_CTX *new_ctx = NULL;
- BIGNUM *tmp, *x, *y, *z;
- int ret = 0, z0;
-
- /* clear error queue */
- ERR_clear_error();
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- y_bit = (y_bit != 0) ? 1 : 0;
-
- BN_CTX_start(ctx);
- tmp = BN_CTX_get(ctx);
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- z = BN_CTX_get(ctx);
- if (z == NULL) goto err;
-
- if (!BN_GF2m_mod_arr(x, x_, group->poly)) goto err;
- if (BN_is_zero(x))
- {
- if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx)) goto err;
- }
- else
- {
- if (!group->meth->field_sqr(group, tmp, x, ctx)) goto err;
- if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) goto err;
- if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err;
- if (!BN_GF2m_add(tmp, x, tmp)) goto err;
- if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx))
- {
- unsigned long err = ERR_peek_last_error();
-
- if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NO_SOLUTION)
- {
- ERR_clear_error();
- ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
- }
- else
- ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
- goto err;
- }
- z0 = (BN_is_odd(z)) ? 1 : 0;
- if (!group->meth->field_mul(group, y, x, z, ctx)) goto err;
- if (z0 != y_bit)
- {
- if (!BN_GF2m_add(y, y, x)) goto err;
- }
- }
-
- if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-
- ret = 1;
+int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group,
+ EC_POINT *point,
+ const BIGNUM *x_, int y_bit,
+ BN_CTX *ctx)
+{
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp, *x, *y, *z;
+ int ret = 0, z0;
+
+ /* clear error queue */
+ ERR_clear_error();
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ y_bit = (y_bit != 0) ? 1 : 0;
+
+ BN_CTX_start(ctx);
+ tmp = BN_CTX_get(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ z = BN_CTX_get(ctx);
+ if (z == NULL)
+ goto err;
+
+ if (!BN_GF2m_mod_arr(x, x_, group->poly))
+ goto err;
+ if (BN_is_zero(x)) {
+ if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx))
+ goto err;
+ } else {
+ if (!group->meth->field_sqr(group, tmp, x, ctx))
+ goto err;
+ if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx))
+ goto err;
+ if (!BN_GF2m_add(tmp, &group->a, tmp))
+ goto err;
+ if (!BN_GF2m_add(tmp, x, tmp))
+ goto err;
+ if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx)) {
+ unsigned long err = ERR_peek_last_error();
+
+ if (ERR_GET_LIB(err) == ERR_LIB_BN
+ && ERR_GET_REASON(err) == BN_R_NO_SOLUTION) {
+ ERR_clear_error();
+ ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES,
+ EC_R_INVALID_COMPRESSED_POINT);
+ } else
+ ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES,
+ ERR_R_BN_LIB);
+ goto err;
+ }
+ z0 = (BN_is_odd(z)) ? 1 : 0;
+ if (!group->meth->field_mul(group, y, x, z, ctx))
+ goto err;
+ if (z0 != y_bit) {
+ if (!BN_GF2m_add(y, y, x))
+ goto err;
+ }
+ }
+
+ if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx))
+ goto err;
+
+ ret = 1;
err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
-
-
-/* Converts an EC_POINT to an octet string.
- * If buf is NULL, the encoded length will be returned.
- * If the length len of buf is smaller than required an error will be returned.
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+}
+
+/*
+ * Converts an EC_POINT to an octet string. If buf is NULL, the encoded
+ * length will be returned. If the length len of buf is smaller than required
+ * an error will be returned.
*/
-size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
- unsigned char *buf, size_t len, BN_CTX *ctx)
- {
- size_t ret;
- BN_CTX *new_ctx = NULL;
- int used_ctx = 0;
- BIGNUM *x, *y, *yxi;
- size_t field_len, i, skip;
-
- if ((form != POINT_CONVERSION_COMPRESSED)
- && (form != POINT_CONVERSION_UNCOMPRESSED)
- && (form != POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
- goto err;
- }
-
- if (EC_POINT_is_at_infinity(group, point))
- {
- /* encodes to a single 0 octet */
- if (buf != NULL)
- {
- if (len < 1)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- return 0;
- }
- buf[0] = 0;
- }
- return 1;
- }
-
-
- /* ret := required output buffer length */
- field_len = (EC_GROUP_get_degree(group) + 7) / 8;
- ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
- /* if 'buf' is NULL, just return required length */
- if (buf != NULL)
- {
- if (len < ret)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- goto err;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- used_ctx = 1;
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- yxi = BN_CTX_get(ctx);
- if (yxi == NULL) goto err;
-
- if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-
- buf[0] = form;
- if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x))
- {
- if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
- if (BN_is_odd(yxi)) buf[0]++;
- }
-
- i = 1;
-
- skip = field_len - BN_num_bytes(x);
- if (skip > field_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- while (skip > 0)
- {
- buf[i++] = 0;
- skip--;
- }
- skip = BN_bn2bin(x, buf + i);
- i += skip;
- if (i != 1 + field_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
-
- if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
- {
- skip = field_len - BN_num_bytes(y);
- if (skip > field_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- while (skip > 0)
- {
- buf[i++] = 0;
- skip--;
- }
- skip = BN_bn2bin(y, buf + i);
- i += skip;
- }
-
- if (i != ret)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- }
-
- if (used_ctx)
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
+size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point,
+ point_conversion_form_t form,
+ unsigned char *buf, size_t len, BN_CTX *ctx)
+{
+ size_t ret;
+ BN_CTX *new_ctx = NULL;
+ int used_ctx = 0;
+ BIGNUM *x, *y, *yxi;
+ size_t field_len, i, skip;
+
+ if ((form != POINT_CONVERSION_COMPRESSED)
+ && (form != POINT_CONVERSION_UNCOMPRESSED)
+ && (form != POINT_CONVERSION_HYBRID)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
+ goto err;
+ }
+
+ if (EC_POINT_is_at_infinity(group, point)) {
+ /* encodes to a single 0 octet */
+ if (buf != NULL) {
+ if (len < 1) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+ buf[0] = 0;
+ }
+ return 1;
+ }
+
+ /* ret := required output buffer length */
+ field_len = (EC_GROUP_get_degree(group) + 7) / 8;
+ ret =
+ (form ==
+ POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2 * field_len;
+
+ /* if 'buf' is NULL, just return required length */
+ if (buf != NULL) {
+ if (len < ret) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
+ goto err;
+ }
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ used_ctx = 1;
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ yxi = BN_CTX_get(ctx);
+ if (yxi == NULL)
+ goto err;
+
+ if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx))
+ goto err;
+
+ buf[0] = form;
+ if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x)) {
+ if (!group->meth->field_div(group, yxi, y, x, ctx))
+ goto err;
+ if (BN_is_odd(yxi))
+ buf[0]++;
+ }
+
+ i = 1;
+
+ skip = field_len - BN_num_bytes(x);
+ if (skip > field_len) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ while (skip > 0) {
+ buf[i++] = 0;
+ skip--;
+ }
+ skip = BN_bn2bin(x, buf + i);
+ i += skip;
+ if (i != 1 + field_len) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ if (form == POINT_CONVERSION_UNCOMPRESSED
+ || form == POINT_CONVERSION_HYBRID) {
+ skip = field_len - BN_num_bytes(y);
+ if (skip > field_len) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ while (skip > 0) {
+ buf[i++] = 0;
+ skip--;
+ }
+ skip = BN_bn2bin(y, buf + i);
+ i += skip;
+ }
+
+ if (i != ret) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ }
+
+ if (used_ctx)
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
err:
- if (used_ctx)
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return 0;
- }
-
-
-/* Converts an octet string representation to an EC_POINT.
- * Note that the simple implementation only uses affine coordinates.
+ if (used_ctx)
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return 0;
+}
+
+/*
+ * Converts an octet string representation to an EC_POINT. Note that the
+ * simple implementation only uses affine coordinates.
*/
int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
- const unsigned char *buf, size_t len, BN_CTX *ctx)
- {
- point_conversion_form_t form;
- int y_bit;
- BN_CTX *new_ctx = NULL;
- BIGNUM *x, *y, *yxi;
- size_t field_len, enc_len;
- int ret = 0;
-
- if (len == 0)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
- return 0;
- }
- form = buf[0];
- y_bit = form & 1;
- form = form & ~1U;
- if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
- && (form != POINT_CONVERSION_UNCOMPRESSED)
- && (form != POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
- if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- if (form == 0)
- {
- if (len != 1)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- return EC_POINT_set_to_infinity(group, point);
- }
-
- field_len = (EC_GROUP_get_degree(group) + 7) / 8;
- enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
- if (len != enc_len)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- yxi = BN_CTX_get(ctx);
- if (yxi == NULL) goto err;
-
- if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
- if (BN_ucmp(x, &group->field) >= 0)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
-
- if (form == POINT_CONVERSION_COMPRESSED)
- {
- if (!EC_POINT_set_compressed_coordinates_GF2m(group, point, x, y_bit, ctx)) goto err;
- }
- else
- {
- if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
- if (BN_ucmp(y, &group->field) >= 0)
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
- if (form == POINT_CONVERSION_HYBRID)
- {
- if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
- if (y_bit != BN_is_odd(yxi))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
- }
-
- if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
- }
-
- if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
- goto err;
- }
-
- ret = 1;
-
+ const unsigned char *buf, size_t len,
+ BN_CTX *ctx)
+{
+ point_conversion_form_t form;
+ int y_bit;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *x, *y, *yxi;
+ size_t field_len, enc_len;
+ int ret = 0;
+
+ if (len == 0) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+ form = buf[0];
+ y_bit = form & 1;
+ form = form & ~1U;
+ if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
+ && (form != POINT_CONVERSION_UNCOMPRESSED)
+ && (form != POINT_CONVERSION_HYBRID)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+ if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ if (form == 0) {
+ if (len != 1) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ return EC_POINT_set_to_infinity(group, point);
+ }
+
+ field_len = (EC_GROUP_get_degree(group) + 7) / 8;
+ enc_len =
+ (form ==
+ POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2 * field_len;
+
+ if (len != enc_len) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ yxi = BN_CTX_get(ctx);
+ if (yxi == NULL)
+ goto err;
+
+ if (!BN_bin2bn(buf + 1, field_len, x))
+ goto err;
+ if (BN_ucmp(x, &group->field) >= 0) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ goto err;
+ }
+
+ if (form == POINT_CONVERSION_COMPRESSED) {
+ if (!EC_POINT_set_compressed_coordinates_GF2m
+ (group, point, x, y_bit, ctx))
+ goto err;
+ } else {
+ if (!BN_bin2bn(buf + 1 + field_len, field_len, y))
+ goto err;
+ if (BN_ucmp(y, &group->field) >= 0) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ goto err;
+ }
+ if (form == POINT_CONVERSION_HYBRID) {
+ if (!group->meth->field_div(group, yxi, y, x, ctx))
+ goto err;
+ if (y_bit != BN_is_odd(yxi)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ goto err;
+ }
+ }
+
+ if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx))
+ goto err;
+ }
+
+ /* test required by X9.62 */
+ if (!EC_POINT_is_on_curve(group, point, ctx)) {
+ ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
+ goto err;
+ }
+
+ ret = 1;
+
err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+}
#endif