Base64编码、解码C语言例子（使用OpenSSL库）

#include
#include
#include
#include
#include
#include
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

注意：

在base64_encode的时候返回的base64编码自带换行，所以大家在使用的时候要注意，以免因为多了个换行而出现bug