將3個獨立的字節數組組合到一個字節數組中

Question

我想將3個字節數組組合成一個字節數組。我嘗試了下面的代碼，我不知道爲什麼不是所有的數組都被複制到一個字節數組中。

似乎正在發生的事情是，所有的hmacDigest數組和密碼數組都正在被複制，但之後密碼數組的一部分再次被複制。我想完成的是將密碼數組，iv數組和hmacDigest數組組合，並將組合的數組存儲到組合的字節數組中。另外，我想這些陣列順序組合：密碼，四，hmacdigest

#include "mbed.h" 

#include "cyassl/ctaocrypt/hmac.h" 
#include "cyassl/ctaocrypt/aes.h" 

#include "MbedJSONValue.h" 
#include "LinearTempSensor.h" 

#include <string> 

using namespace std; 

Serial pc(USBTX, USBRX); 

LinearTempSensor sensor(p20, 300, LinearTempSensor::MCP9701); 
MbedJSONValue sensorResults; 

Aes enc; 
Aes dec; 

Hmac hmac; 

float Vout, Tav, To, TempValue; 

std::string s; 

int main() { 

    pc.baud(115200); 

    const byte key[16] = { 0x6d, 0x6e, 0x62, 0x76, 0x63, 0x78, 0x7a, 0x6c, 0x6b, 0x6a, 0x68, 0x67, 0x66, 0x64, 0x73, 0x61 }; 
    const byte iv[16] = { 0x61, 0x73, 0x64, 0x66, 0x67, 0x68, 0x6a, 0x6b, 0x6c, 0x70, 0x6f, 0x69, 0x75, 0x79, 0x74, 0x72 }; 

    byte plain[128] = { 'a', 'b', 'c', 'd', 'e', 'f' }; // an increment of 16, fill with data 
    byte cipher[128]; 
    byte deciphered[128]; 

    byte hkey[24] = { 0x8b, 0x21, 0x31, 0x21, 0xb7, 0xbe, 0x33, 0x1a, 0xcf, 0x1f, 0x71, 0x70, 0x45, 0xaf, 0x5c, 0x02, 0xa7, 0xa1, 0x4c, 0x34, 0xd4, 0xbc, 0x4b, 0x4a }; // fill key with keying material 
    byte buffer[2048]; // fill buffer with data to digest 
    byte hmacDigest[SHA256_DIGEST_SIZE]; 

    Vout = sensor.Sense();   // Sample data (read sensor) 
    Tav = sensor.GetAverageTemp(); // Calculate average temperature from N samples 
    To = sensor.GetLatestTemp(); // Calculate temperature from the latest sample 

    TempValue = sensor.GetAverageTemp(); 

    //Create JSON 
    sensorResults["DATA1"][0] = "Result"; 
    sensorResults["DATA1"][1] = 5.5; 
    sensorResults["DATA2"][0] = "Result"; 
    sensorResults["DATA2"][1] = 700; 
    sensorResults["DATA3"][0] = "Result"; 
    sensorResults["DATA3"][1] = TempValue; 

    //Serialize JSON 
    s = sensorResults.serialize(); 
    //sl = s.size(); 

    //Print JSON string 
    pc.printf("json: %s\r\n", s.c_str()); 

    //Convert JSON string to a char array to encrypt 
    //char *a=new char[s.size()+1]; 
    plain[s.size()]=0; 
    memcpy(plain,s.c_str(),s.size());//<-- Fills plain array with the JSON values 

    // encrypt 
    AesSetKey(&enc, key, sizeof(key), iv, AES_ENCRYPTION); 
    AesCbcEncrypt(&enc, cipher, plain, sizeof(plain)); 

    HmacSetKey(&hmac, SHA256, hkey, sizeof(key)); 
    HmacUpdate(&hmac, buffer, sizeof(buffer)); 
    HmacFinal(&hmac, hmacDigest); 

    //cipher now contains the cipher text from the plain text. 

    pc.printf("\r\nAES Key: "); 
    for(int i=0; i<sizeof(key); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     pc.printf("%.2X",key[i]); 
    } 

    pc.printf("\r\nAES IV: "); 
    for(int i=0; i<sizeof(iv); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     pc.printf("%.2X",iv[i]); 
    } 

    pc.printf("\r\nPlain HEX: "); 
    for(int i=0; i<sizeof(plain); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     pc.printf("%.2X",plain[i]); 
    } 

    pc.printf("\r\nEncrypted: "); 
    for(int i=0; i<sizeof(cipher); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     pc.printf("%.2X",cipher[i]); 
    } 

    pc.printf("\r\nhmacDigest: "); 
    for(int i=0; i<sizeof(hmacDigest); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     pc.printf("%.2X",hmacDigest[i]); 
    } 

    // decrypt 
    AesSetKey(&dec, key, sizeof(key), iv, AES_DECRYPTION); 
    AesCbcDecrypt(&dec, deciphered, cipher, sizeof(cipher)); 

    pc.printf("\r\nDecrypted: "); 
    for(int i=0; i<sizeof(deciphered); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     //pc.printf("%.2X",deciphered[i]); 
     pc.printf("%c",deciphered[i]); 
    } 

    //Combine the EncryptedData + IV + HMAC 
    const int S_CIPHER = sizeof(cipher); 
    const int S_IV = sizeof(iv); 
    const int S_HMACDIGEST = sizeof(hmacDigest); 

    const int S_TOTAL = S_CIPHER + S_IV + S_HMACDIGEST; 

    byte combined[S_TOTAL]; 
    //Copy arrays in individually. 
    memcpy(combined, cipher, S_CIPHER); 
    memcpy(combined, iv, S_IV); 
    memcpy(combined, hmacDigest, S_HMACDIGEST); 

    pc.printf("\r\nOutput: "); 
    for(int i=0; i<sizeof(combined); i++) 
    { 
     //if(i%16==0) pc.printf("\r\n"); 
     //pc.printf("%.2X",deciphered[i]); 
     pc.printf("%.2X",combined[i]); 
    } 
} 

Answer 1

您的memcpy數組總是在相同的點組合陣列

它更改爲：

memcpy(combined, cipher, S_CIPHER); 
memcpy(combined+S_CIPHER, iv, S_IV); 
memcpy(combined+S_CIPHER+S_IV, hmacDigest, S_HMACDIGEST); 

memcpy原型是

無效*memcpy(void *dest, const void *src, size_t n);

您必須將dest指針移動到每次複製單個陣列時的正確位置。