Go实战--go中使用base64加密(The way to go)

生命不止，继续 Go go go !!!

base64加密你一点也不会陌生，Base64是网络上最常见的用于传输8Bit字节代码的编码方式之一，大家可以查看RFC2045～RFC2049，上面有MIME的详细规范。Base64编码可用于在HTTP环境下传递较长的标识信息。

首先介绍介绍一下老本行，C++中是如何进行base64加密解密的，直接上代码了：
base64.h

#include <string>#ifndef _BASE64_H_#define _BASE64_H_ __declspec(dllexport)  std::string base64_encode(unsigned char const*, unsigned int len); __declspec(dllexport)  std::string base64_decode(std::string const& s);#endif

base64.cc

#include "base64.h"#include <iostream>static const std::string base64_chars =              "ABCDEFGHIJKLMNOPQRSTUVWXYZ"             "abcdefghijklmnopqrstuvwxyz"             "0123456789+/";static inline bool is_base64(unsigned char c) {  return (isalnum(c) || (c == '+') || (c == '/'));}std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {  std::string ret;  int i = 0, j = 0;  unsigned char char_array_3[3], char_array_4[4];  while (in_len--)    {    char_array_3[i++] = *(bytes_to_encode++);    if (i == 3)         {      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);      char_array_4[3] = char_array_3[2] & 0x3f;      for(i = 0; (i <4) ; i++)        ret += base64_chars[char_array_4[i]];      i = 0;    }  }  if (i)  {    for(j = i; j < 3; j++)      char_array_3[j] = '\0';    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);    char_array_4[3] = char_array_3[2] & 0x3f;    for (j = 0; (j < i + 1); j++)      ret += base64_chars[char_array_4[j]];    while((i++ < 3))      ret += '=';  }  return ret;}std::string base64_decode(std::string const& encoded_string) {  int in_len = encoded_string.size();  int i = 0, j = 0, in_ = 0;  unsigned char char_array_4[4], char_array_3[3];  std::string ret;  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_]))     {    char_array_4[i++] = encoded_string[in_]; in_++;    if (i ==4) {      for (i = 0; i <4; i++)        char_array_4[i] = base64_chars.find(char_array_4[i]);      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];      for (i = 0; (i < 3); i++)        ret += char_array_3[i];      i = 0;    }  }  if (i)     {    for (j = i; j <4; j++)      char_array_4[j] = 0;    for (j = 0; j <4; j++)      char_array_4[j] = base64_chars.find(char_array_4[j]);    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);    char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];    for (j = 0; (j < i - 1); j++)             ret += char_array_3[j];  }  return ret;}

下面就进行介绍在golang中如何进行base64加密。

encoding/base64
Package base64 implements base64 encoding as specified by RFC 4648.

StdEncoding
StdEncoding is the standard base64 encoding, as defined in RFC 4648.

NewDecoder

func NewDecoder(enc *Encoding, r io.Reader) io.Reader

NewDecoder constructs a new base64 stream decoder.

EncodeToString

func (enc *Encoding) EncodeToString(src []byte) string

EncodeToString returns the base64 encoding of src.

应用：

package mainimport (    "encoding/base64"    "fmt")func main() {    s := "heal the world, make it a better place"    encodeStd := "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"    s64 := base64.NewEncoding(encodeStd).EncodeToString([]byte(s))    fmt.Println("base64.NewEncoding(encodeStd).EncodeToString")    fmt.Println(len(s))    fmt.Println(len(s64))    fmt.Println(s)    fmt.Println(s64)    s64_std := base64.StdEncoding.EncodeToString([]byte(s))    fmt.Println("base64.StdEncoding.EncodeToString")    fmt.Println(len(s))    fmt.Println(len(s64_std))    fmt.Println(s)    fmt.Println(s64_std)}

输出结果：
base64.NewEncoding(encodeStd).EncodeToString
38
52
heal the world, make it a better place
aGVhbCB0aGUgd29ybGQsIG1ha2UgaXQgYSBiZXR0ZXIgcGxhY2U=

base64.StdEncoding.EncodeToString
38
52
heal the world, make it a better place
aGVhbCB0aGUgd29ybGQsIG1ha2UgaXQgYSBiZXR0ZXIgcGxhY2U=