c - 简单的 base64 解码不起作用 :(

Question

我一直在尝试使用以下代码对输入的 char * 进行 base64 解码。“msg”的值似乎是一个空字符串:(

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <openssl/bn.h>
#include <openssl/bio.h>
#include <openssl/objects.h>
#include <openssl/pem.h>
#include <openssl/objects.h>

// reads b64 encoded msg (pReadBuffer) and writes to pWriiteFile.
char *  dgstdecode(char *pReadBuffer, int pLength)
{
     char *msg = (char *)malloc(pLength);
    memset(msg, 0x00, pLength);
    int readbytes = -1;

    printf("inside dgstdecode\n");
    printf("\n pReadBuffer = %s \n", pReadBuffer);
    BIO *b64, *bio = NULL;
    b64 = BIO_new(BIO_f_base64());
    bio = BIO_new_mem_buf(pReadBuffer, pLength);
    bio = BIO_push(b64, bio);
   //BIO_set_flags(bio,BIO_FLAGS_BASE64_NO_NL);

    while ((readbytes = BIO_read(bio, msg, pLength)) > 0)
    {
    printf("readbytes:  %d\n", readbytes);
    printf("inside dgstdecode\n");
    }
    BIO_flush(bio);
    printf("msg = %s\n", msg);
    BIO_free_all(bio);
    //BIO_free_all(b64);
    return msg;

}


int main(int argc, char *argv[])
{
    int i = 0;
    char buff [9] ="aGVsbG8K" ;
    //memset(buff, 0, 9);
    char* ptr ;
    ptr = (char*)malloc(9);

    for(i =0;i < 4; i++){

        buff[9] = '\0';

        printf("strlen buff = %d\n", strlen(buff));
        ptr = dgstdecode(buff, 9);
        printf("ptr = %s\n", ptr);
    }

    return 0;

}

Answer 1

对不起!这是正确的方法。我刚刚清理了主要功能:

int main(int argc, char *argv[])
{
    int i = 0;
    char buff [] ="aGVsbG8K\n\0" ;
    char* ptr ;

    for(i =0;i < 4; i++){

        printf("strlen buff = %d\n", strlen(buff));
        ptr = dgstdecode(buff, strlen(buff));
        printf("ptr = %s\n", ptr);
        printf("\n");
    }

    return 0;
}

我现在的输出是(仍在执行删除/n 的操作):

strlen 增益 = 9在 dgstdecode 里面

pReadBuffer = aGVsbG8K

读取字节数:6在 dgstdecode 里面消息 = 你好

ptr = 你好

strlen 增益 = 9在 dgstdecode 里面

pReadBuffer = aGVsbG8K

读取字节数:6在 dgstdecode 里面消息 = 你好

ptr = 你好

strlen 增益 = 9在 dgstdecode 里面

pReadBuffer = aGVsbG8K

读取字节数:6在 dgstdecode 里面消息 = 你好

ptr = 你好

strlen 增益 = 9在 dgstdecode 里面

pReadBuffer = aGVsbG8K

读取字节数:6在 dgstdecode 里面消息 = 你好

ptr = 你好

请忽略我下面的原始回复:

bio = BIO_push(b64, bio); 行似乎是罪魁祸首。它似乎正在覆盖引用。这是我评论该行后的输出(编辑器似乎删除了一些/n):

strlen buff = 8
inside dgstdecode

 pReadBuffer = aGVsbG8K 
readbytes:  9
inside dgstdecode
msg = aGVsbG8K
ptr = aGVsbG8K

strlen buff = 8
inside dgstdecode

 pReadBuffer = aGVsbG8K 
readbytes:  9
inside dgstdecode
msg = aGVsbG8K
ptr = aGVsbG8K

strlen buff = 8
inside dgstdecode

 pReadBuffer = aGVsbG8K 
readbytes:  9
inside dgstdecode
msg = aGVsbG8K
ptr = aGVsbG8K

strlen buff = 8
inside dgstdecode

 pReadBuffer = aGVsbG8K 
readbytes:  9
inside dgstdecode
msg = aGVsbG8K
ptr = aGVsbG8K