c - 如何在 C 编程中循环遍历字节数组并将其存储为十六进制字符串

Question

如何在 C 编程中循环遍历字节数组，并将字符串中每个字节元素的十六进制输出存储为十六进制。我使用的是VS2005。

int main(int ArgC,char** ArgV)
{
    char*           string;
    char            stringSHA1[3];
    char*           stringSHA1Final = "";
    Sha1Context     sha1Context;
    SHA1_HASH       sha1Hash;
    uint16_t        i;

    string = "Hello World";//ArgV[1];

    Sha1Initialise( &sha1Context );
    Sha1Update( &sha1Context, string, (uint32_t)strlen(string) );
    Sha1Finalise( &sha1Context, &sha1Hash );

    stringSHA1Final = malloc(sizeof(sha1Hash)*2 + 1);

    for( i=0; i<sizeof(sha1Hash); i++ )
    {
        printf( "%2.2x", sha1Hash.bytes[i] );
        sprintf_s(stringSHA1, 5, "%s%02x", "0x", sha1Hash.bytes[i] );
        stringSHA1Final[i] = stringSHA1;
    }
    printf( stringSHA1Final );

    return 0;
}

我在将十六进制字符串连接成单个字符串并返回时遇到了麻烦。

Answer 1

您可以使用指针，如下所示

char *sha1final = stringSHA1Final;
for (i = 0 ; i < sizeof(sha1Hash) ; i++)
 {
    int count;
    count = snprintf(sha1final, 2, "%02x", sha1Hash.bytes[i]);
    if (count < 0)
        continue; /* You have to handle this, it's an error */
    sha1final += count;
 }