c/c++语言开发共享evp_encrypt不能在c中的for循环中工作

我是新来的,所以请原谅我做错了什么。

我尝试使用加密字符串创建一个数组,我正在使用EVP API进行加密。 这工作正常,但是我尝试在foor循环中使用加密function,控制台什么也没给我。

这是我的加密function:

char *encrypt(char *key, char *iv, char * source){ //char *target; int in_len, out_len; EVP_CIPHER_CTX ctx; in_len=strlen((const char *)source); unsigned char *target = (unsigned char *) malloc(in_len); //printf("This is the text before ciphering: %sn",source); //printf("The length of the string is: %dn",in_len); //starting the encryption process EVP_CIPHER_CTX_init(&ctx); EVP_EncryptInit_ex(&ctx,EVP_aes_128_cbc(),NULL,(unsigned char*) key,(unsigned char*)iv); EVP_EncryptUpdate(&ctx,target,&out_len,(unsigned char*)source,in_len); EVP_EncryptFinal_ex(&ctx,target,&out_len); target[out_len] = ''; //EVP_CIPHER_CTX_cleanup(&ctx); return ((char *)target); } 

并在主循环中:

 int main(){ char source[17]="Shahababamamaaaa"; char key[17]="ahardtobreakkey1"; char iv[17] = "veryinterestingv"; int rows = 1280; int cols = (3*800)/16; char *encrypted=encrypt(key, iv, source); printf("encrypted: %sn", encrypted); char *encrypted2; encrypted2=encrypt(key, iv, encrypted); printf("encrypted2: %sn", encrypted2); char *mx[rows]; char *in, *temp; in = (char *) malloc ( cols * sizeof(char) ); temp =(char *) malloc ( strlen(encrypted) ); int i, j; for (i=0; i<5; i++){ strcpy(in,encrypted); for(j=0;j<3;j++){ printf("in: %sn", in); strcpy(temp, encrypted2); printf("temp: %sn", temp); memset(encrypted2,0x00, strlen(encrypted)); encrypted2=encrypt(key, iv,temp); printf("encrypted2 nach j=%d : %sn",j, encrypted2); mx[i]=in; } } printf("Stele 0 Inhalt %sn",mx[0]); printf("Laenge von 1 %dn", strlen(mx[0])); //system ("PAUSE"); free(in); return 0; } 

我错过了什么? 再次使用encrypt2是不可能的吗? 非常感谢你。

    正如您所说,主要问题在于您的encrypt()函数,以及您如何调用它。 您正在使用malloc()在函数内部分配内存,并且永远不会释放它,这是一个内存泄漏(无论如何,malloc在c ++中都是禁忌)。 您也没有为ctx运行清理function。 而你的encrypt_final正在覆盖输出缓冲区的第一部分。 所以,这是一个清理的encrypt()和一个匹配的decrypt():

     int encrypt(unsigned char *key, unsigned char *iv, unsigned char * source, unsigned char* target, int in_len) // Need an in length. Not all input is going to be // zero-terminated, for example if we're reading from a file { int out_len; // Return the output length. Because it also won't be null // terminated, and may contain null characters inline int final_out_len; // So that we don't overwrite out_len with the final call EVP_CIPHER_CTX ctx; EVP_CIPHER_CTX_init(&ctx); EVP_EncryptInit_ex(&ctx,EVP_aes_128_cbc(),NULL,key,iv); EVP_EncryptUpdate(&ctx,target,&out_len,source,in_len); EVP_EncryptFinal_ex(&ctx,target+out_len,&final_out_len); EVP_CIPHER_CTX_cleanup(&ctx); return out_len+final_out_len; // need to sum these together, because both // encrypt calls wrote data } 

    并解密:

     int decrypt(unsigned char *key, unsigned char *iv, unsigned char * source, unsigned char* target, int in_len) { int out_len=0,final_out_len=0; EVP_CIPHER_CTX ctx; EVP_CIPHER_CTX_init(&ctx); EVP_DecryptInit_ex(&ctx,EVP_aes_128_cbc(),NULL,key,iv); EVP_DecryptUpdate(&ctx,target,&out_len,source,in_len); EVP_DecryptFinal_ex(&ctx,target+out_len,&final_out_len); EVP_CIPHER_CTX_cleanup(&ctx); //Just to be nice, we'll add a zero at the end of the decrypted string target[out_len+final_out_len] = 0; return out_len+final_out_len; } 

    把它们拉在一起(循环,以certificate你的概念):

     int _tmain(int argc, _TCHAR* argv[]) { unsigned char key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; unsigned char ivec[] = {1,2,3,4,5,6,7,8}; char *raw_buffer = "This is a test string"; int raw_count = strlen(raw_buffer); for (int i=0; i<5; i++){ unsigned char *decrypted_buffer = new unsigned char[raw_count+64]; unsigned char *encrypted_buffer = new unsigned char[raw_count+64]; int final_len = encrypt(key,ivec,(unsigned char*)raw_buffer,(unsigned char*)encrypted_buffer,raw_count); int dec_len = decrypt(key,ivec,(unsigned char*)encrypted_buffer,(unsigned char*)decrypted_buffer,final_len); printf("raw_count: %infinal_len: %indec_len: %in",raw_count,final_len,dec_len); printf("Original str: n%sn",raw_buffer); printf("Encrypted: n%sn", encrypted_buffer); printf("Decrypted:n%snnn", decrypted_buffer); delete[] decrypted_buffer; delete[] encrypted_buffer; } char c; c=getchar(); return 0; } 

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