diff options
Diffstat (limited to 'openssl/crypto/ec/ec2_oct.c')
| -rw-r--r-- | openssl/crypto/ec/ec2_oct.c | 620 |
1 files changed, 308 insertions, 312 deletions
diff --git a/openssl/crypto/ec/ec2_oct.c b/openssl/crypto/ec/ec2_oct.c index f1d75e5dd..c245d886d 100644 --- a/openssl/crypto/ec/ec2_oct.c +++ b/openssl/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 |