asn1c_constraint.c

来自「RSA加密/解密算法源码 asn1c-0.9.12」· C语言 代码 · 共 630 行 · 第 1/2 页

			 */
			asn1constraint_range_free(range);
			return 0;
		} else {
			utf8_full_alphabet_check = 1;
		}
	} else {
		/*
		 * This permitted alphabet check will be
		 * expressed using conditional statements
		 * instead of table lookups. Table would be
		 * to large or otherwise inappropriate (too sparse?).
		 */
	}

	OUT("static int check_permitted_alphabet_%d(const void *sptr) {\n",
			arg->expr->_type_unique_index);
	INDENT(+1);
	if(utf8_full_alphabet_check) {
		OUT("if(UTF8String_length((const UTF8String_t *)sptr) < 0)\n");
		OUT("\treturn -1; /* Alphabet (sic!) test failed. */\n");
		OUT("\n");
	} else {
		if(use_table) {
			OUT("int *table = permitted_alphabet_table_%d;\n",
				arg->expr->_type_unique_index);
			emit_alphabet_check_loop(arg, 0);
		} else {
			emit_alphabet_check_loop(arg, range);
		}
	}
	OUT("return 0;\n");
	INDENT(-1);
	OUT("}\n");
	OUT("\n");

	asn1constraint_range_free(range);

	return 1;
}

static int
emit_alphabet_check_loop(arg_t *arg, asn1cnst_range_t *range) {
	asn1c_integer_t natural_stop;
	asn1p_expr_t *terminal;
	char *tname;

	terminal = asn1f_find_terminal_type_ex(arg->asn, arg->expr);
	if(terminal) {
		OUT("/* The underlying type is %s */\n",
			ASN_EXPR_TYPE2STR(terminal->expr_type));
	} else {
		terminal = arg->expr;
	}
	tname = asn1c_type_name(arg, terminal, TNF_SAFE);
	OUT("const %s_t *st = (const %s_t *)sptr;\n", tname, tname);

	switch(terminal->expr_type) {
	case ASN_STRING_UTF8String:
		OUT("const uint8_t *ch = st->buf;\n");
		OUT("const uint8_t *end = ch + st->size;\n");
		OUT("\n");
		OUT("for(; ch < end; ch++) {\n");
			INDENT(+1);
			OUT("uint8_t cv = *ch;\n");
			if(!range) OUT("if(cv >= 0x80) return -1;\n");
		natural_stop = 0xffffffffUL;
		break;
	case ASN_STRING_UniversalString:
		OUT("const uint8_t *ch = st->buf;\n");
		OUT("const uint8_t *end = ch + st->size;\n");
		OUT("\n");
		OUT("if(st->size %% 4) return -1; /* (size%%4)! */\n");
		OUT("for(; ch < end; ch += 4) {\n");
			INDENT(+1);
			OUT("uint32_t cv = (ch[0] << 24)\n");
			OUT("\t\t| (ch[1] << 16)\n");
			OUT("\t\t| (ch[2] << 8)\n");
			OUT("\t\t|  ch[3];\n");
			if(!range) OUT("if(cv > 255) return -1;\n");
		natural_stop = 0xffffffffUL;
		break;
	case ASN_STRING_BMPString:
		OUT("const uint8_t *ch = st->buf;\n");
		OUT("const uint8_t *end = ch + st->size;\n");
		OUT("\n");
		OUT("if(st->size %% 2) return -1; /* (size%%2)! */\n");
		OUT("for(; ch < end; ch += 2) {\n");
			INDENT(+1);
			OUT("uint16_t cv = (ch[0] << 8)\n");
			OUT("\t\t| ch[1];\n");
			if(!range) OUT("if(cv > 255) return -1;\n");
		natural_stop = 0xffff;
		break;
	case ASN_BASIC_OCTET_STRING:
	default:
		OUT("const uint8_t *ch = st->buf;\n");
		OUT("const uint8_t *end = ch + st->size;\n");
		OUT("\n");
		OUT("for(; ch < end; ch++) {\n");
			INDENT(+1);
			OUT("uint8_t cv = *ch;\n");
		natural_stop = 0xff;
		break;
	}

	if(range) {
		OUT("if(!(");
		emit_range_comparison_code(arg, range, "cv", 0, natural_stop);
		OUT(")) return -1;\n");
	} else {
		OUT("if(!table[cv]) return -1;\n");
	}

	INDENT(-1);
	OUT("}\n");

	return 0;
}

static int
emit_range_comparison_code(arg_t *arg, asn1cnst_range_t *range, const char *varname, asn1c_integer_t natural_start, asn1c_integer_t natural_stop) {
	int ignore_left;
	int ignore_right;
	int generated_something = 0;
	int i;

	for(i = -1; i < range->el_count; i++) {
		asn1cnst_range_t *r;
		if(i == -1) {
			if(range->el_count) continue;
			r = range;
		} else {
			if(i) OUT(" || ");
			r = range->elements[i];
		}

		if(r != range) OUT("(");

		ignore_left = (r->left.type == ARE_MIN)
				|| (natural_start != -1
					&& r->left.value <= natural_start);
		ignore_right = (r->right.type == ARE_MAX)
				|| (natural_stop != -1
					&& r->right.value >= natural_stop);
		if(ignore_left && ignore_right) {
			OUT("1 /* Constraint matches natural range of %s */",
				varname);
			continue;
		}

		if(ignore_left) {
			OUT("%s <= %" PRIdASN, varname,
				r->right.value);
		} else if(ignore_right) {
			OUT("%s >= %" PRIdASN, varname,
				r->left.value);
		} else if(r->left.value == r->right.value) {
			OUT("%s == %" PRIdASN, varname,
				r->right.value);
		} else {
			OUT("%s >= %" PRIdASN " && %s <= %" PRIdASN,
				varname,
				r->left.value,
				varname,
				r->right.value);
		}
		if(r != range) OUT(")");
		generated_something = 1;
	}

	return generated_something;
}

static int
emit_size_determination_code(arg_t *arg, asn1p_expr_type_e etype) {

	switch(etype) {
	case ASN_BASIC_BIT_STRING:
		OUT("if(st->size > 0) {\n");
		OUT("\t/* Size in bits */\n");
		OUT("\tsize = 8 * (st->size - 1) - (st->buf[0] & 0x7);\n");
		OUT("} else {\n");
		OUT("\tsize = 0;\n");
		OUT("}\n");
		break;
	case ASN_STRING_UniversalString:
		OUT("size = st->size >> 2;\t/* 4 byte per character */\n");
		break;
	case ASN_STRING_BMPString:
		OUT("size = st->size >> 1;\t/* 2 byte per character */\n");
		break;
	case ASN_STRING_UTF8String:
		OUT("size = UTF8String_length(st);\n");
		OUT("if((ssize_t)size < 0) {\n");
		OUT("\t_ASN_ERRLOG(app_errlog, app_key,\n");
		OUT("\t\t\"%%s: UTF-8: broken encoding (%%s:%%d)\",\n");
		OUT("\t\ttd->name, __FILE__, __LINE__);\n");
		OUT("\treturn -1;\n");
		OUT("}\n");
		break;
	case ASN_CONSTR_SET_OF:
	case ASN_CONSTR_SEQUENCE_OF:
		OUT("{ /* Determine the number of elements */\n");
			INDENT(+1);
			OUT("const A_%s_OF(void) *list;\n",
				etype==ASN_CONSTR_SET_OF?"SET":"SEQUENCE");
			OUT("(const void *)list = sptr;\n");
			OUT("size = list->count;\n");
			INDENT(-1);
		OUT("}\n");
		break;
	case ASN_BASIC_OCTET_STRING:
		OUT("size = st->size;\n");
		break;
	default:
		if(etype & ASN_STRING_MASK) {
			OUT("size = st->size;\n");
			break;
		} else {
			const char *type_name = ASN_EXPR_TYPE2STR(etype);
			if(!type_name) type_name = arg->expr->Identifier;
			WARNING("SizeConstraint is not defined for %s",
				type_name);
			OUT_NOINDENT("#warning SizeConstraint "
				"is not defined for %s!\n", type_name);
			OUT("size = st->size;\n");
		}
		return -1;
	}

	return 0;
}

static int
emit_value_determination_code(arg_t *arg, asn1p_expr_type_e etype, asn1cnst_range_t *r_value) {

	switch(etype) {
	case ASN_BASIC_INTEGER:
	case ASN_BASIC_ENUMERATED:
		if(arg->flags & A1C_USE_NATIVE_TYPES) {
			OUT("value = *(const long *)sptr;\n");
		} else {
			if(r_value->el_count == 0
			&& (
				/* Speed-up common case: (0..MAX) */
				(r_value->left.type == ARE_VALUE
				&& r_value->left.value == 0
				&& r_value->right.type == ARE_MAX)
			    ||
				/* Speed-up common case: (MIN..-1) */
				(r_value->left.type == ARE_MIN
				&& r_value->right.type == ARE_VALUE
				&& r_value->right.value == -1)
			)) {
				OUT("/* Check if the sign bit is present */\n");
				OUT("value = st->buf ? ((st->buf[0] & 0x80) ? -1 : 1) : 0;\n");
				break;
			}

			OUT("if(asn_INTEGER2long(st, &value)) {\n");
				INDENT(+1);
				OUT("_ASN_ERRLOG(app_errlog, app_key,\n");
				OUT("\t\"%%s: value too large (%%s:%%d)\",\n");
				OUT("\ttd->name, __FILE__, __LINE__);\n");
				OUT("return -1;\n");
				INDENT(-1);
			OUT("}\n");
		}
		break;
	case ASN_BASIC_REAL:
		if(arg->flags & A1C_USE_NATIVE_TYPES) {
			OUT("value = *(const double *)sptr;\n");
		} else {
			OUT("if(asn_REAL2double(st, &value)) {\n");
				INDENT(+1);
				OUT("_ASN_ERRLOG(app_errlog, app_key,\n");
				OUT("\t\"%%s: value too large (%%s:%%d)\",\n");
				OUT("\ttd->name, __FILE__, __LINE__);\n");
				OUT("return -1;\n");
				INDENT(-1);
			OUT("}\n");
		}
		break;
	case ASN_BASIC_BOOLEAN:
		OUT("value = (*(const long *)sptr) ? 1 : 0;\n");
		break;
	default:
		WARNING("%s:%d: Value cannot be determined "
			"for constraint check for %s",
			arg->mod->source_file_name,
			arg->expr->_lineno,
			arg->expr->Identifier
		);
		OUT_NOINDENT(
			"#error %s:%d: Value of %s cannot be determined\n",
			arg->mod->source_file_name,
			arg->expr->_lineno,
			arg->expr->Identifier
		);
		break;
	}

	return 0;
}

static asn1p_expr_type_e
_find_terminal_type(arg_t *arg) {
	asn1p_expr_t *expr;
	expr = asn1f_find_terminal_type_ex(arg->asn, arg->expr);
	if(expr) return expr->expr_type;
	return A1TC_INVALID;
}