code

Plugins/MqttClient/Source/DTMqtt/MqttC/utf-8.c

@@ -0,0 +1,217 @@
+// Copyright 2023 Dexter.Wan. All Rights Reserved. 
+// EMail: 45141961@qq.com
+
+#include "utf-8.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "StackTrace.h"
+
+/**
+ * Macro to determine the number of elements in a single-dimension array
+ */
+#if !defined(ARRAY_SIZE)
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
+#endif
+
+
+/**
+ * Structure to hold the valid ranges of UTF-8 characters, for each byte up to 4
+ */
+struct
+{
+	int len; /**< number of elements in the following array (1 to 4) */
+	struct
+	{
+		char lower; /**< lower limit of valid range */
+		char upper; /**< upper limit of valid range */
+	} bytes[4];   /**< up to 4 bytes can be used per character */
+}
+valid_ranges[] =
+{
+		{1, { {00, 0x7F} } },
+		{2, { {0xC2, 0xDF}, {0x80, 0xBF} } },
+		{3, { {0xE0, 0xE0}, {0xA0, 0xBF}, {0x80, 0xBF} } },
+		{3, { {0xE1, 0xEC}, {0x80, 0xBF}, {0x80, 0xBF} } },
+		{3, { {0xED, 0xED}, {0x80, 0x9F}, {0x80, 0xBF} } },
+		{3, { {0xEE, 0xEF}, {0x80, 0xBF}, {0x80, 0xBF} } },
+		{4, { {0xF0, 0xF0}, {0x90, 0xBF}, {0x80, 0xBF}, {0x80, 0xBF} } },
+		{4, { {0xF1, 0xF3}, {0x80, 0xBF}, {0x80, 0xBF}, {0x80, 0xBF} } },
+		{4, { {0xF4, 0xF4}, {0x80, 0x8F}, {0x80, 0xBF}, {0x80, 0xBF} } },
+};
+
+
+static const char* UTF8_char_validate(int len, const char* data);
+
+
+/**
+ * Validate a single UTF-8 character
+ * @param len the length of the string in "data"
+ * @param data the bytes to check for a valid UTF-8 char
+ * @return pointer to the start of the next UTF-8 character in "data"
+ */
+static const char* UTF8_char_validate(int len, const char* data)
+{
+	int good = 0;
+	int charlen = 2;
+	int i, j;
+	const char *rc = NULL;
+
+	if (data == NULL)
+		goto exit;	/* don't have data, can't continue */
+
+	/* first work out how many bytes this char is encoded in */
+	if ((data[0] & 128) == 0)
+		charlen = 1;
+	else if ((data[0] & 0xF0) == 0xF0)
+		charlen = 4;
+	else if ((data[0] & 0xE0) == 0xE0)
+		charlen = 3;
+
+	if (charlen > len)
+		goto exit;	/* not enough characters in the string we were given */
+
+	for (i = 0; i < ARRAY_SIZE(valid_ranges); ++i)
+	{ /* just has to match one of these rows */
+		if (valid_ranges[i].len == charlen)
+		{
+			good = 1;
+			for (j = 0; j < charlen; ++j)
+			{
+				if (data[j] < valid_ranges[i].bytes[j].lower ||
+						data[j] > valid_ranges[i].bytes[j].upper)
+				{
+					good = 0;  /* failed the check */
+					break;
+				}
+			}
+			if (good)
+				break;
+		}
+	}
+
+	if (good)
+		rc = data + charlen;
+	exit:
+	return rc;
+}
+
+
+/**
+ * Validate a length-delimited string has only UTF-8 characters
+ * @param len the length of the string in "data"
+ * @param data the bytes to check for valid UTF-8 characters
+ * @return 1 (true) if the string has only UTF-8 characters, 0 (false) otherwise
+ */
+int MQTT_UTF8_validate(int len, const char* data)
+{
+	const char* curdata = NULL;
+	int rc = 0;
+
+	FUNC_ENTRY;
+	if (len == 0 || data == NULL)
+	{
+		rc = 1;
+		goto exit;
+	}
+	curdata = UTF8_char_validate(len, data);
+	while (curdata && (curdata < data + len))
+		curdata = UTF8_char_validate((int)(data + len - curdata), curdata);
+
+	rc = curdata != NULL;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+ * Validate a null-terminated string has only UTF-8 characters
+ * @param string the string to check for valid UTF-8 characters
+ * @return 1 (true) if the string has only UTF-8 characters, 0 (false) otherwise
+ */
+int MQTT_UTF8_validateString(const char* string)
+{
+	int rc = 0;
+
+	FUNC_ENTRY;
+	if (string != NULL)
+	{
+		rc = MQTT_UTF8_validate((int)strlen(string), string);
+	}
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+
+#if defined(UNIT_TESTS)
+#include <stdio.h>
+
+typedef struct
+{
+	int len;
+	char data[20];
+} tests;
+
+tests valid_strings[] =
+{
+		{3, "hjk" },
+		{7, {0x41, 0xE2, 0x89, 0xA2, 0xCE, 0x91, 0x2E} },
+		{3, {'f', 0xC9, 0xB1 } },
+		{9, {0xED, 0x95, 0x9C, 0xEA, 0xB5, 0xAD, 0xEC, 0x96, 0xB4} },
+		{9, {0xE6, 0x97, 0xA5, 0xE6, 0x9C, 0xAC, 0xE8, 0xAA, 0x9E} },
+		{4, {0x2F, 0x2E, 0x2E, 0x2F} },
+		{7, {0xEF, 0xBB, 0xBF, 0xF0, 0xA3, 0x8E, 0xB4} },
+};
+
+tests invalid_strings[] =
+{
+		{2, {0xC0, 0x80} },
+		{5, {0x2F, 0xC0, 0xAE, 0x2E, 0x2F} },
+		{6, {0xED, 0xA1, 0x8C, 0xED, 0xBE, 0xB4} },
+		{1, {0xF4} },
+};
+
+int main (int argc, char *argv[])
+{
+	int i, failed = 0;
+
+	for (i = 0; i < ARRAY_SIZE(valid_strings); ++i)
+	{
+		if (!MQTT_UTF8_validate(valid_strings[i].len, valid_strings[i].data))
+		{
+			printf("valid test %d failed\n", i);
+			failed = 1;
+		}
+		else
+			printf("valid test %d passed\n", i);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(invalid_strings); ++i)
+	{
+		if (MQTT_UTF8_validate(invalid_strings[i].len, invalid_strings[i].data))
+		{
+			printf("invalid test %d failed\n", i);
+			failed = 1;
+		}
+		else
+			printf("invalid test %d passed\n", i);
+	}
+
+	if (failed)
+		printf("Failed\n");
+	else
+		printf("Passed\n");
+
+    //Don't crash on null data
+	MQTT_UTF8_validateString(NULL);
+	MQTT_UTF8_validate(1, NULL);
+	UTF8_char_validate(1, NULL);
+
+	return 0;
+} /* End of main function*/
+
+#endif
+