base58加密解密的C语言实现

解码函数部分参考

(42条消息) BASE58 编码 解码 C语言 (比特币)_Qode的博客-CSDN博客

在其基础上进行修改，编译环境VS2022，直接F5完美运行

#include 
#include 
#include 

unsigned char* en_base58(unsigned char* input)  // 编码
{
    static char* nb58 = (char*)"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
    size_t len = strlen((char*)input);
    size_t rlen = (len / 2 + 1) * 3;
    unsigned char* ret = (unsigned char*)malloc(rlen + len);
    unsigned char* src = ret + rlen;
    unsigned char* rptr = ret + rlen;
    unsigned char* ptr, * e = src + len - 1;
    size_t i;
    memcpy(src, input, len);
    while (src <= e)
    {
        if (*src)
        {
            unsigned char rest = 0;
            ptr = src;
            while (ptr <= e)
            {
                unsigned int c = rest * 256;
                rest = (c + *ptr) % 58;
                *ptr = (c + *ptr) / 58;
                ptr++;
            }
            --rptr;
            *rptr = nb58[rest];
        }
        else
        {
            src++;
        }
    }
    for (i = 0; i < ret + rlen - rptr; i++)
        ret[i] = rptr[i];
    ret[i] = 0;
    return ret;
}

bool de_base58(unsigned char* src)  // 解码
{
    static char b58n[] =
    {
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1,  0,  1,  2,  3,  4,  5,  6,  7,  8, -1, -1, -1, -1, -1, -1,
        -1,  9, 10, 11, 12, 13, 14, 15, 16, -1, 17, 18, 19, 20, 21, -1,
        22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, -1, -1, -1, -1, -1,
        -1, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, -1, 44, 45, 46,
        47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    };
    size_t len = strlen((char*)src);
    size_t rlen = (len / 4 + 1) * 3;
    unsigned char* ret = (unsigned char*)malloc(rlen);
    unsigned char* rptr = ret + rlen;
    size_t i;
    unsigned char* ptr;
    for (i = 0; i < len; i++)
    {
        char rest = b58n[src[i]];
        if (rest < 0)
        {
            free(ret);
            return NULL;
        }
        for (ptr = ret + rlen - 1; ptr >= rptr; ptr--)
        {
            unsigned int c = rest + *ptr * 58;
            *ptr = c % 256;
            rest = c / 256;
        }
        if (rest > 0)
        {
            rptr--;
            if (rptr < ret)
            {
                free(ret);
                return NULL;
            }
            *rptr = rest;
        }
    }
    for (i = 0; i < ret + rlen - rptr; i++)
        ret[i] = rptr[i];
    ret[i] = 0;
    memcpy(src, ret, strlen((char*)src));
}

int main()
{
    char str[] = "9EGJCxbxRGT";
    printf("%sn", en_base58((unsigned char*)"12345678"));
    de_base58((unsigned char*)str);
    printf("%s", str);
    getchar();
    return 0;
}