c++安全传输平台——老师结构体编码与解码(ASN.1编码解码)

素颜马尾好姑娘i 2022-10-31 13:42 420阅读 0赞

### 文章目录 ###

*  安全传输平台之老师结构体编码与解码
 *   *  demo1
     *   *  主函数
         *  mywritefile函数
         *  解码
         *  编码
     *  itcast\_asn1\_der.h
     *  itcast\_asn1\_der.c

# 安全传输平台之老师结构体编码与解码 #

老师结构体编码与解码

## demo1 ##

#define _CRT_SECURE_NO_WARNINGS
    #include "stdio.h"
    #include "stdlib.h"
    #include "string.h"
    #include "itcast_asn1_der.h"
    #include "itcastderlog.h"
    
    //老师结构体
    typedef struct _Teacher
    { 
    	char name[64];
    	int age;
    	char *p;
    	int plen;
    }Teacher;
    
    //释放内存
    void freeTeacher(Teacher **pTeacher)
    { 
    	if (pTeacher == NULL) { 
    		return;
    	}
    	if (pTeacher != NULL) { 
    		if ((*pTeacher)->p != NULL) { 
    			free((*pTeacher)->p);
    			(*pTeacher)->p = NULL;
    		}
    		free(*pTeacher);
    		*pTeacher = NULL;
    	}
    }
    
    
    //解码
    //int TeacherDecode(unsigned char *indata, int inLen, Teacher **pStruct)
    
    //持久化
    //int mywritefile(unsigned char *buf, int len)
    
    //主函数
    //int main(void)

### 主函数 ###

int main(void)
    { 
    	int					ret = 0;
    
    	Teacher				t1;
    	Teacher  *pt2 = NULL;
    
    	unsigned char		*myOut = NULL;
    	int					myOutlen = 0;
    
    	t1.age = 10;
    	strcpy(t1.name, "myName");
    	t1.p = malloc(64);
    	strcpy(t1.p, "aaaabbbb");
    	t1.plen = strlen(t1.p);
    
    	TeacherEncode(&t1, &myOut, &myOutlen);
    	mywritefile(myOut, myOutlen);
    
    	TeacherDecode(myOut, myOutlen, &pt2);
    
    	if (strcmp(t1.name, pt2->name) == 0 &&
    		memcmp(t1.p, pt2->p, pt2->plen) == 0) 
    	{ 
    		printf("编码 == 解码 \n");
    	}
    	else
    	{ 
    		printf("编码 != 解码 \n");
    	}
    
    	freeTeacher(&pt2);
    
    	printf("hello...\n");
    	system("pause");
    
    	return 0;
    }

### mywritefile函数 ###

int mywritefile(unsigned char *buf, int len)
    { 
    	FILE *fp = NULL;
    	fp = fopen("c:/itcast/teacher.ber", "wb+");
    	if (fp == NULL)
    	{ 
    		printf("fopen file error \n");
    		return -1;
    	}
    	fwrite(buf, 1, len, fp);
    	fclose(fp);
    	return 0;
    }

### 解码 ###

int TeacherDecode(unsigned char *indata, int inLen, Teacher **pStruct)
    { 
    	int					ret = 0;
    	ITCAST_ANYBUF		*pTmp = NULL, *pHead = NULL;
    	ITCAST_ANYBUF		*pOutData = NULL;
    	ITCAST_ANYBUF		*tmpAnyBuf = NULL;
    
    	Teacher *pStrTeacher = NULL;
    
    	// 转码 BER 报文 unsigned char * --> ITCAST_ANYBUF
    	ret = DER_ITCAST_String_To_AnyBuf(&tmpAnyBuf, indata, inLen);
    	if (ret != 0) { 
    		if (tmpAnyBuf != NULL) 
    			DER_ITCAST_FreeQueue(tmpAnyBuf);
    
    		printf(" Decode DER_ITCAST_String_To_AnyBuf error: %d\n", ret);
    		return ret;
    	}
    
    	// 解码大Teacher 结构体
    	ret = DER_ItAsn1_ReadSequence(tmpAnyBuf, &pHead);
    	if (ret != 0) { 
    		if (tmpAnyBuf != NULL)
    			DER_ITCAST_FreeQueue(tmpAnyBuf);
    		printf(" Decode DER_ItAsn1_ReadSequence error: %d\n", ret);
    		return ret;
    	}
    
    	// 给Teacher 结构体 malloc 空间。
    	if (pStrTeacher == NULL) { 
    		pStrTeacher = (Teacher *)malloc(sizeof(Teacher));
    		if (pStrTeacher == NULL) { 
    			DER_ITCAST_FreeQueue(pHead);
    			ret = -1;
    			printf("Teacher malloc error: %d\n", ret);
    			return ret;
    		}
    		memset(pStrTeacher, 0, sizeof(Teacher));
    	}
    
    	pTmp = pHead;
    
    	// 解码 name
    	ret = DER_ItAsn1_ReadPrintableString(pTmp, &pOutData);
    	if (ret != 0) { 
    		DER_ITCAST_FreeQueue(pHead);
    		freeTeacher(&pStrTeacher);
    
    		printf(" Decode DER_ItAsn1_ReadPrintableString name error: %d\n", ret);
    		return ret;
    	}
    
    	// ppPrintString -> pData; ---> name
    	memcpy(pStrTeacher->name, pOutData->pData, pOutData->dataLen);
    	
    	pTmp = pTmp->next;
    	// 解码age
    	ret = DER_ItAsn1_ReadInteger(pTmp, &pStrTeacher->age);
    	if (ret != 0) { 
    		DER_ITCAST_FreeQueue(pHead);
    		freeTeacher(&pStrTeacher);
    		printf(" Decode DER_ItAsn1_ReadInteger age error: %d\n", ret);
    		return ret;
    	}
    
    	pTmp = pTmp->next;
    	// 解码 p
    	ret = DER_ItAsn1_ReadPrintableString(pTmp, &pOutData);
    	if (ret != 0) { 
    		DER_ITCAST_FreeQueue(pHead);
    		freeTeacher(&pStrTeacher);
    		printf(" Decode DER_ItAsn1_ReadPrintableString p error: %d\n", ret);
    		return ret;
    	}
    	// 给Teacher 结构体中的 p 指针开辟空间
    	pStrTeacher->p = malloc(pOutData->dataLen + 1);
    	if (pStrTeacher->p == NULL) { 
    		DER_ITCAST_FreeQueue(pHead);
    		freeTeacher(&pStrTeacher);
    		ret = -2;
    		printf("Teacher->p malloc error: %d\n", ret);
    		return ret;
    	}
    	memcpy(pStrTeacher->p, pOutData->pData, pOutData->dataLen);
    	//pStrTeacher->p[pOutData->dataLen - 4] = 'R';
    	pStrTeacher->p[pOutData->dataLen] = '\0';
    
    	pTmp = pTmp->next;
    	// 解码plen
    	ret = DER_ItAsn1_ReadInteger(pTmp, &pStrTeacher->plen);
    	if (ret != 0) { 
    		DER_ITCAST_FreeQueue(pHead);
    		freeTeacher(&pStrTeacher);
    		printf(" Decode DER_ItAsn1_ReadInteger plen error: %d\n", ret);
    		return ret;
    	}
    
    	*pStruct = pStrTeacher;
    
    	return 0;
    }

### 编码 ###

// 传入、传出、传入传出。
    int TeacherEncode(Teacher *pThecher, unsigned char **out, int *outlen)
    { 
    	int					ret = 0;
    	ITCAST_ANYBUF		*pTmp = NULL, *pHeadBuf = NULL;
    	ITCAST_ANYBUF		*pTmpBuf = NULL;
    	ITCAST_ANYBUF		*pOutData = NULL;
    
    	unsigned char		*tmpout = NULL;
    	int					tmpoutlen = 0;
    
    	//将 char * 类型的name 转换成 ITCAST_ANYBUF 类型
    	ret = DER_ITCAST_String_To_AnyBuf(&pTmpBuf, pThecher->name, strlen(pThecher->name));
    	if (ret != 0) { 
    		printf("DER_ITCAST_String_To_AnyBuf error: %d\n", ret);
    		return ret;
    	}
    
    	// 编码 name --> TLV
    	ret = DER_ItAsn1_WritePrintableString(pTmpBuf, &pHeadBuf);
    	if (ret != 0) { 
    		DER_ITCAST_FreeQueue(pTmpBuf);
    		printf("DER_ItAsn1_WritePrintableString error: %d\n", ret);
    		return ret;
    	}
    	DER_ITCAST_FreeQueue(pTmpBuf);
    
    	pTmp = pHeadBuf;
    
    	// 编码 age
    	ret = DER_ItAsn1_WriteInteger(pThecher->age, &(pTmp->next));
    	if (ret != 0) { 
    		printf("DER_ItAsn1_WriteInteger error: %d\n", ret);
    		return ret;
    	}
    	pTmp = pTmp->next;
    
    	//编码 p char *
    	ret = EncodeChar(pThecher->p, pThecher->plen, &pTmp->next);
    	if (ret != 0) { 
    		printf("EncodeChar error: %d\n", ret);
    		return ret;
    	}
    	pTmp = pTmp->next;
    
    	//编码 plen
    	ret = DER_ItAsn1_WriteInteger(pThecher->plen, &(pTmp->next));
    	if (ret != 0) { 
    		printf("DER_ItAsn1_WriteInteger plen error: %d\n", ret);
    		return ret;
    	}
    
    	//编码大结构体
    	ret = DER_ItAsn1_WriteSequence(pHeadBuf, &pOutData);
    	if (ret != 0) { 
    		DER_ITCAST_FreeQueue(pHeadBuf);
    		printf("DER_ItAsn1_WriteSequence error: %d\n", ret);
    		return ret;
    	}
    
    
    
    	*out = pOutData->pData;
    
    	*outlen = pOutData->dataLen;
    
    	return 0;
    }

说明1

// 编码 age
    	ret = DER_ItAsn1_WriteInteger(pThecher->age, &(pTmp->next));

与

//编码 p char *
    	ret = EncodeChar(pThecher->p, pThecher->plen, &pTmp->next);

这两段代码中，`&(pTmp->next)`和`&pTmp->next`是一样的，因为后操作符优先。  
说明2

Teacher *pStrTeacher = NULL;
        
    	// 给Teacher 结构体 malloc 空间。
    	if (pStrTeacher == NULL) { 
    		pStrTeacher = (Teacher *)malloc(sizeof(Teacher));
    		if (pStrTeacher == NULL) { 
    			DER_ITCAST_FreeQueue(pHead);
    			ret = -1;
    			printf("Teacher malloc error: %d\n", ret);
    			return ret;
    		}
    		memset(pStrTeacher, 0, sizeof(Teacher));
    	}

常用用`malloc`来开辟空间，`memset`来初始化空间。  
C 库函数 - memset()

C 库函数 void *memset(void *str, int c, size_t n) 复制字符 c（一个无符号字符）到参数 str 所指向的字符串的前 n 个字符。

C 库函数 - malloc()

C 库函数 void *malloc(size_t size) 分配所需的内存空间，并返回一个指向它的指针。

## itcast\_asn1\_der.h ##

部分关键代码

//别名
    typedef int					ITCAST_INT ;
    typedef unsigned char       ITCAST_UINT8;
    typedef unsigned short      ITCAST_UINT16;
    typedef unsigned long		ITCAST_UINT32;
    typedef signed long         ITCAST_SINT32;
    
    //结构体
    typedef struct ITCAST_ANYBUF_{ 
    	
        unsigned char 	  *pData;
        ITCAST_UINT32     dataLen;
        
        ITCAST_UINT32     unusedBits;  /* for bit string */  
        ITCAST_UINT32     memoryType;
        ITCAST_UINT32     dataType;
        struct ITCAST_ANYBUF_ *next;    /* for sequence and set */
        struct ITCAST_ANYBUF_ *prev;
        
    }ITCAST_ANYBUF;
     
     //别名
    typedef ITCAST_UINT8     ITASN1_BOOLEAN;
    typedef ITCAST_ANYBUF    ITASN1_INTEGER;
    typedef ITCAST_ANYBUF    ITASN1_OCTETSTRING;
    typedef ITCAST_ANYBUF    ITASN1_BITSTRING;
    typedef ITCAST_ANYBUF    ITASN1_PRINTABLESTRING;
    /*begin of bmpstring*/
    typedef ITCAST_ANYBUF	 ITASN1_BMPSTRING;
    /*end of bmpstring*/
    typedef ITCAST_ANYBUF    ITASN1_ENUMERATED;
    typedef ITCAST_ANYBUF    ITASN1_IA5STRING;
    typedef ITCAST_ANYBUF    ITASN1_SEQUENCE;
    typedef ITCAST_ANYBUF    ITASN1_SET; 
    
    
    //函数
    ITCAST_INT
    DER_ItAsn1_WriteInteger(ITCAST_UINT32 integer, ITASN1_INTEGER **ppDerInteger);
    
    ITCAST_INT
    DER_ItAsn1_ReadInteger(ITASN1_INTEGER *pDerInteger, ITCAST_UINT32 *pInteger);
    
    ITCAST_INT
    DER_ItAsn1_WriteBitString(ITASN1_BITSTRING *pBitString,ITASN1_BITSTRING **ppDerBitString);
    
    ITCAST_INT
    DER_ItAsn1_ReadBitString(ITASN1_BITSTRING *pDerBitString,ITASN1_BITSTRING **ppBitString);
    
    
    ITCAST_INT
    DER_ItAsn1_WritePrintableString(ITASN1_PRINTABLESTRING *pPrintString, 
    ITASN1_PRINTABLESTRING **ppDerPrintString);
    
    ITCAST_INT
    DER_ItAsn1_ReadPrintableString(ITASN1_PRINTABLESTRING *pDerPrintString, 
    ITASN1_PRINTABLESTRING **ppPrintString);
    
    ITCAST_INT
    DER_ItAsn1_WriteSequence(ITASN1_SEQUENCE *pSequence, ITCAST_ANYBUF **ppDerSequence);
    
    ITCAST_INT
    DER_ItAsn1_ReadSequence(ITCAST_ANYBUF *pDerSequence, ITASN1_SEQUENCE **ppSequence);
    
    ITCAST_INT
    DER_ItAsn1_WriteNull(ITCAST_ANYBUF ** ppDerNull);
    
    ITCAST_INT
    DER_ItAsn1_ReadNull(ITCAST_ANYBUF * ppDerNull, ITCAST_UINT8 * pInt);
    
    ITCAST_INT 
    DER_ITCAST_FreeQueue(ITCAST_ANYBUF *pAnyBuf);
    
    ITCAST_INT
    DER_ITCAST_String_To_AnyBuf(ITCAST_ANYBUF **pOriginBuf,	unsigned char *strOrigin, int strOriginLen);
    
    int WriteNullSequence(ITCAST_ANYBUF **pOutData);
    
    int EncodeChar(char *pData, int dataLen, ITCAST_ANYBUF **outBuf);
    
    int EncodeUnsignedChar(unsigned char *pData, int dataLen, ITCAST_ANYBUF **outBuf);
    
    int DecodeChar(ITCAST_ANYBUF *inBuf, char **Data, int *pDataLen);

## itcast\_asn1\_der.c ##

DER\_ITCAST\_String\_To\_AnyBuf

ITCAST_INT
    DER_ITCAST_String_To_AnyBuf(ITCAST_ANYBUF **pOriginBuf,
    	unsigned char * strOrigin,
    	int  strOriginLen)
    { 
    	ITCAST_ANYBUF *pValueBuf;
    
    	pValueBuf = malloc(sizeof(ITCAST_ANYBUF));
    	if (pValueBuf == NULL)
    	{ 
    		ITDER_LOG(__FILE__, __LINE__,LogLevel[4], ITDER_MemoryErr,"malloc err");
    		return ITDER_MemoryErr;
    	}
    	memset(pValueBuf,0,sizeof(ITCAST_ANYBUF));
    
    	if(strOriginLen <= 0)
    	{ 
    		pValueBuf ->pData = NULL;
    		strOriginLen = 0;
    	}
    	else
    	{ 
    		pValueBuf->pData =(unsigned char *)malloc(strOriginLen);
    		if (pValueBuf->pData == NULL)
    		{ 
    			DER_ITCAST_Free(pValueBuf);
    			ITDER_LOG(__FILE__, __LINE__,LogLevel[4], ITDER_LengthErr,"malloc err");
    			return ITDER_MemoryErr;
    		}	
    		memcpy(pValueBuf->pData,strOrigin,strOriginLen); 
    	}
    	pValueBuf->dataLen =  strOriginLen;
    	pValueBuf->dataType = ITCAST_DER_ID_STRING_PRINTABLE;
    	pValueBuf->next = NULL;
     	pValueBuf->prev = NULL;
    	pValueBuf->unusedBits = (strOriginLen % 8);
    	pValueBuf->memoryType = 0;
    	*pOriginBuf = pValueBuf; 
    	return ITDER_NoErr;
    }

DER\_ItAsn1\_WritePrintableString

//DER编码PrintableString类型数据
    ITCAST_INT
    DER_ItAsn1_WritePrintableString(
        ITASN1_PRINTABLESTRING *pPrintString,
        ITASN1_PRINTABLESTRING **ppDerPrintString)
    { 
    	int iResult;
    	
    	if (pPrintString->dataType == ITCAST_DER_STRING_BMP)
    	{ 
    		iResult = DER_ItAsn1_WriteBmpString(pPrintString,ppDerPrintString);
            if (iResult != ITDER_NoErr)
    		{ 
    			ITDER_LOG(__FILE__, __LINE__,LogLevel[4], iResult,"func DER_ItAsn1_WriteBmpString() err");
    			return  iResult;	
    		}
    	
    	}
    	else
        { 
    		iResult = DER_ItAsn1_WriteCharString(pPrintString,ppDerPrintString);
            if (iResult != ITDER_NoErr)
    		{ 
    			ITDER_LOG(__FILE__, __LINE__,LogLevel[4], iResult,"func DER_ItAsn1_WriteCharString() err");
    			return  iResult;	
    		}
    	}
    	
    	return 0;
    }