Base64编码、解码 C语言例子（使用OpenSSL库）

朱雀 2022-02-28 07:28 704阅读 0赞

#include <stdio.h>
    #include <string.h>
    #include <unistd.h>
     
    #include <openssl/pem.h>
    #include <openssl/bio.h>
    #include <openssl/evp.h>
     
    int base64_encode(char *in_str, int in_len, char *out_str)
    {
        BIO *b64, *bio;
        BUF_MEM *bptr = NULL;
        size_t size = 0;
     
        if (in_str == NULL || out_str == NULL)
            return -1;
     
        b64 = BIO_new(BIO_f_base64());
        bio = BIO_new(BIO_s_mem());
        bio = BIO_push(b64, bio);
     
        BIO_write(bio, in_str, in_len);
        BIO_flush(bio);
     
        BIO_get_mem_ptr(bio, &bptr);
        memcpy(out_str, bptr->data, bptr->length);
        out_str[bptr->length] = '\0';
        size = bptr->length;
     
        BIO_free_all(bio);
        return size;
    }
     
    int base64_decode(char *in_str, int in_len, char *out_str)
    {
        BIO *b64, *bio;
        BUF_MEM *bptr = NULL;
        int counts;
        int size = 0;
     
        if (in_str == NULL || out_str == NULL)
            return -1;
     
        b64 = BIO_new(BIO_f_base64());
        BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
     
        bio = BIO_new_mem_buf(in_str, in_len);
        bio = BIO_push(b64, bio);
     
        size = BIO_read(bio, out_str, in_len);
        out_str[size] = '\0';
     
        BIO_free_all(bio);
        return size;
    }
     
    int main()
    {
    	char instr[] = "hello";
    	char outstr1[1024] = {0};
    	base64_encode(instr,5,outstr1);
    	printf("base64:%s\n",outstr1);
     
    	char outstr2[1024] = {0};
    	base64_decode(outstr1,strlen(outstr1),outstr2);
    	printf("str:%s\n",outstr2);
    	return 0;
    
    }

编译及运行：

$ gcc base64.c -lcrypto

$ ./a.out

结果：

base64:aGVsbG8=  
  
str:hello

ref:[https://blog.csdn.net/lell3538/article/details/59137414][https_blog.csdn.net_lell3538_article_details_59137414]

[https_blog.csdn.net_lell3538_article_details_59137414]: https://blog.csdn.net/lell3538/article/details/59137414