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- DES算法通过Java/C#/Python等语言实现很简单,有现成的封装库。
- C语言实现则比较麻烦,找了半天才找到合适的算法实现。
- 本实例主要实现DES+EBC+PKSC5/PKSC7的加解密算法
- 源码开源:小康师兄 / DES (https://gitee.com/weijian.kang/DES)
ZeroPadding
、PKCS5Padding
和PKCS7Padding
等等
ZeroPadding
填充0数据,简单粗暴,但是缺点很明显,如果原始数据中就0数据,就无法判断是填充的数据,还是填充的数据。PKCS5Padding
填充的数据==填充数据的长度。
###
,填充后:###55555
;#####
,填充后:#####333
;PKCS7Padding
是为了支持AES,在PKCS5Padding
上进行扩展。PKCS5Padding
是针对8个字节块算法进行填充。PKCS7Padding
则最大可以到255个字节的块算法。所以,对DES来说,PKCS5Padding
和PKCS7Padding
这两种填充方式是一样的。ECB
和CBC
ECB
:电子文本方式,相对简单CBC
:密文分组连接方式,相对复杂,不易破解。需要增加参数:偏移向量IV。Windows系统上可以选择VSCode搭建C语言开发环境,也可以选择Dev-C++集成开发工具
#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include "stdio.h"
#include "stdlib.h"
#include "crypto.h"
//密钥
const unsigned char key[]="abcdefgh";
unsigned char key_len=strlen((const char*)key);
//明文
const unsigned char plaintext[]="12345678";
int main()
{
int ret=0;
int out_len=8;
unsigned char *des_out, *base64_out, *out;
printf("\r\nkey|%d: %s\r\n\r\n", key_len, key);
printf("====================plaintext des encrypt===================\r\n");
out_len = strlen((const char*)plaintext);
printf("plaintext|%d: %s\r\n", out_len, plaintext);
//des 加密
ret=des_encrypt(DES_ECB, key, key_len, NULL, plaintext, &des_out, &out_len);
printf("des_encrypt res=%d, len=%d, out=", ret, out_len);
printHex(des_out, out_len);
//base64 编码
ret=base64_en(des_out, &base64_out, &out_len);
printf("base64_en res=%d, len=%d, out=%s\r\n", ret, out_len, base64_out);
free(base64_out);
free(des_out);
printf("=======================================\r\n\r\n");
printf("====================ciphertext des decrypt===================\r\n");
out_len = strlen((const char*)base64_out);
printf("ciphertext|%d: %s\r\n", out_len, base64_out);
//base64 解码
ret=base64_de(base64_out, &out, &out_len);
printf("base64_de res=%d, len=%d, out=", ret, out_len);
printHex(out, out_len);
//des 解密
ret=des_decrypt(DES_ECB, key, key_len, NULL, out, &des_out, &out_len);
des_out[out_len]='\0';
printf("des_decrypt res=%d, len=%d, out=%s\r\n", ret, out_len, des_out);
free(des_out);
free(out);
printf("=======================================\r\n\r\n");
}
crypto.h
#ifndef __CRYPTO_H
#define __CRYPTO_H
typedef enum{
DES_ECB =0,
DES_CBC,
DES3_ECB,
DES3_CBC,
}CRYPTO_TYPE;
typedef enum{
RESULT_TYPE_BIN =0,//bin类型
RESULT_TYPE_STR_UPPER,//HEX大写字符串
RESULT_TYPE_STR_LOWER,//HEX小写字符串
}MD5_RESULT_TYPE;
typedef enum{
RESULT_OK = 0,
RESULT_ERROR,
}CRYPTO_RESULT;
#ifdef __cplusplus
extern "C" {
#endif
/*
DES 加密
type[in]:加密方式
key[in] 秘钥 des 固定8位 3des可为8位 16位 24位
keyLen[in] 秘钥长度,des固定为8,3des可为8 16 24
vi[in] 偏移 固定8位, CBC方式可用,ECB 为null
in[in] 待加密数据
out[out] 加密后数据(需要free)
len[in/out] 传入待加密数据长度,传出加密后数据长度
return 是否成功
*/
CRYPTO_RESULT des_encrypt(CRYPTO_TYPE type, const unsigned char key[], unsigned char keyLen, const unsigned char vi[8], const unsigned char in[],unsigned char **out,int *len);
/*
DES 解密
type[in]:解密方式
key[in] 秘钥 des 固定8位 3des可为8位 16位 24位
keyLen[in] 秘钥长度,des固定为8,3des可为8 16 24
vi[in] 偏移 固定8位, CBC方式可用,ECB 为null
in[in] 待解密数据
out[out] 解密后数据(需要free)
len[in/out] 传入待解密数据长度,传出解密后数据长度
return 是否成功
*/
CRYPTO_RESULT des_decrypt(CRYPTO_TYPE type, const unsigned char key[], unsigned char keyLen, const unsigned char vi[8], const unsigned char in[],unsigned char **out,int *len);
/*
BASE64编码
type[in]:结果方式
in[in] 待编码的数据
out[out] 编码后数据(需要free)
len[in/out] 传入编码要数据长度,传出编码后数据长度
return 是否成功
*/
CRYPTO_RESULT base64_en(const unsigned char in[],unsigned char **out,int *len);
/*
BASE64解码
type[in]:结果方式
in[in] 待解码的数据
out[out] 解码后数据(需要free)
len[in/out] 传入编码要数据长度,传出编码后数据长度
return 是否成功
*/
CRYPTO_RESULT base64_de(const unsigned char in[],unsigned char **out,int *len);
void printHex(unsigned char *data , int len);
#ifdef __cplusplus
}
#endif
#endif
crypto.c
#include <string.h>
#include "stdio.h"
#include "stdlib.h"
#include "crypto.h"
#include "des.h"
#include "base64.h"
void printHex(unsigned char *data , int len){
int i = 0;
for(i = 0; i < len; i++){
//printf("%02X ",data[i]);
printf("%02x",data[i]);
}
printf("\n");
}
static unsigned char* pack_padding_pkcs5(const unsigned char in[], int *len){
unsigned char paddNum = 8 - *len % 8;
unsigned char *data = (unsigned char *)malloc(*len + paddNum);
int i = 0;
memset(data, 0, *len + paddNum);
memcpy(data, in, *len);
for (i = 0; i < paddNum; i++) {
data[*len + i] = paddNum;
}
*len = *len + paddNum;
return data;
}
static unsigned char* unpack_padding_pkcs5(const unsigned char in[], int *len){
unsigned char paddNum = in[*len - 1];
if(paddNum > 8){
*len = 0;
return NULL;
}
*len = *len - paddNum;
unsigned char *data = (unsigned char *)malloc(*len);
memset(data, 0, *len);
memcpy(data, in, *len );
return data;
}
CRYPTO_RESULT des_encrypt(CRYPTO_TYPE type, const unsigned char key[], unsigned char keyLen, const unsigned char vi[8], const unsigned char in[],unsigned char **out,int *len){
unsigned char *data = pack_padding_pkcs5(in,len);
*out = (unsigned char *)malloc(*len);
if(type == DES_ECB || type == DES_CBC){
mbedtls_des_context context;
mbedtls_des_init(&context);
mbedtls_des_setkey_enc(&context, key);
if(type == DES_ECB){
int i = 0;
int num = *len / 8;
for(i = 0; i < num; i++){
mbedtls_des_crypt_ecb(&context, data + i * 8, *out + i * 8);
}
}else{
unsigned char v[8] = {0};
memcpy(v,vi,8);
mbedtls_des_crypt_cbc(&context,MBEDTLS_DES_ENCRYPT,*len, v, data, *out);
}
}else if(type == DES3_ECB || type == DES3_CBC){
mbedtls_des3_context context;
if(keyLen != 8 && keyLen != 16 && keyLen != 24){
return RESULT_ERROR;
}
unsigned char k[24] = {0};
memcpy(k,key,keyLen);
mbedtls_des3_init(&context);
mbedtls_des3_set3key_enc(&context, k);
if(type == DES3_ECB){
int i = 0;
int num = *len / 8;
for(i = 0; i < num; i++){
mbedtls_des3_crypt_ecb(&context, data + i * 8, *out + i * 8);
}
}else{
unsigned char v[8] = {0};
memcpy(v,vi,8);
mbedtls_des3_crypt_cbc(&context,MBEDTLS_DES_ENCRYPT,*len, v, data, *out);
}
}
free(data);
return RESULT_OK;
}
CRYPTO_RESULT des_decrypt(CRYPTO_TYPE type, const unsigned char key[], unsigned char keyLen, const unsigned char vi[8], const unsigned char in[],unsigned char **out,int *len){
if(*len % 8){
return RESULT_ERROR;
}
unsigned char *data = (unsigned char *)malloc(*len);
if(type == DES_ECB || type == DES_CBC){
mbedtls_des_context context;
mbedtls_des_init(&context);
mbedtls_des_setkey_dec(&context, key);
if(type == DES_ECB){
int i = 0;
int num = *len / 8;
for(i = 0; i < num; i++){
mbedtls_des_crypt_ecb(&context, in + i * 8, data + i * 8);
}
}else{
unsigned char v[8] = {0};
memcpy(v,vi,8);
mbedtls_des_crypt_cbc(&context,MBEDTLS_DES_DECRYPT,*len, v, in, data);
}
}else if(type == DES3_ECB || type == DES3_CBC){
mbedtls_des3_context context;
if(keyLen != 8 && keyLen != 16 && keyLen != 24){
return RESULT_ERROR;
}
unsigned char k[24] = {0};
memcpy(k,key,keyLen);
mbedtls_des3_init(&context);
mbedtls_des3_set3key_dec(&context, k);
if(type == DES3_ECB){
int i = 0;
int num = *len / 8;
for(i = 0; i < num; i++){
mbedtls_des3_crypt_ecb(&context, in + i * 8, data + i * 8);
}
}else{
unsigned char v[8] = {0};
memcpy(v,vi,8);
mbedtls_des3_crypt_cbc(&context,MBEDTLS_DES_DECRYPT,*len, v, in, data);
}
}
*out = unpack_padding_pkcs5(data,len);
free(data);
if(*len == 0){
return RESULT_ERROR;
}
return RESULT_OK;
}
CRYPTO_RESULT base64_en(const unsigned char in[],unsigned char **out,int *len){
unsigned char *encode_out;
encode_out = (unsigned char*)malloc(BASE64_ENCODE_OUT_SIZE(*len));
*len = base64_encode(in, *len, (char *)encode_out);
if(*len > 0){
*out = (unsigned char*)malloc(*len + 1);
memset(*out,0,*len + 1);
memcpy(*out,encode_out,*len);
free(encode_out);
return RESULT_OK;
}else{
*out = (unsigned char*)malloc(1);
*out[0] = 0;
*len = 0;
free(encode_out);
return RESULT_ERROR;
}
}
CRYPTO_RESULT base64_de(const unsigned char in[],unsigned char **out,int *len){
unsigned char *decode_out;
decode_out = (unsigned char*)malloc(BASE64_DECODE_OUT_SIZE(*len));
*len = base64_decode((const char*)in, *len, decode_out);
if(*len > 0){
*out = (unsigned char*)malloc(*len);
memset(*out,0,*len);
memcpy(*out,decode_out,*len);
free(decode_out);
return RESULT_OK;
}else{
*out = (unsigned char*)malloc(1);
*out[0] = 0;
*len = 0;
free(decode_out);
return RESULT_ERROR;
}
}
des.h
/**
* \file des.h
*
* \brief DES block cipher
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
/*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*
*/
#ifndef MBEDTLS_DES_H
#define MBEDTLS_DES_H
#include <stddef.h>
#include <stdint.h>
#define MBEDTLS_DES_ENCRYPT 1
#define MBEDTLS_DES_DECRYPT 0
#define MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH -0x0032 /**< The data input has an invalid length. */
#define MBEDTLS_ERR_DES_HW_ACCEL_FAILED -0x0033 /**< DES hardware accelerator failed. */
#define MBEDTLS_DES_KEY_SIZE 8
#ifdef __cplusplus
extern "C" {
#endif
// Regular implementation
//
/**
* \brief DES context structure
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
typedef struct mbedtls_des_context
{
uint32_t sk[32]; /*!< DES subkeys */
}
mbedtls_des_context;
/**
* \brief Triple-DES context structure
*/
typedef struct mbedtls_des3_context
{
uint32_t sk[96]; /*!< 3DES subkeys */
}
mbedtls_des3_context;
/**
* \brief Initialize DES context
*
* \param ctx DES context to be initialized
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
void mbedtls_des_init( mbedtls_des_context *ctx );
/**
* \brief Clear DES context
*
* \param ctx DES context to be cleared
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
void mbedtls_des_free( mbedtls_des_context *ctx );
/**
* \brief Initialize Triple-DES context
*
* \param ctx DES3 context to be initialized
*/
void mbedtls_des3_init( mbedtls_des3_context *ctx );
/**
* \brief Clear Triple-DES context
*
* \param ctx DES3 context to be cleared
*/
void mbedtls_des3_free( mbedtls_des3_context *ctx );
/**
* \brief DES key schedule (56-bit, encryption)
*
* \param ctx DES context to be initialized
* \param key 8-byte secret key
*
* \return 0
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
int mbedtls_des_setkey_enc( mbedtls_des_context *ctx, const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
/**
* \brief DES key schedule (56-bit, decryption)
*
* \param ctx DES context to be initialized
* \param key 8-byte secret key
*
* \return 0
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
int mbedtls_des_setkey_dec( mbedtls_des_context *ctx, const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
/**
* \brief Triple-DES key schedule (112-bit, encryption)
*
* \param ctx 3DES context to be initialized
* \param key 16-byte secret key
*
* \return 0
*/
int mbedtls_des3_set2key_enc( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 2] );
/**
* \brief Triple-DES key schedule (112-bit, decryption)
*
* \param ctx 3DES context to be initialized
* \param key 16-byte secret key
*
* \return 0
*/
int mbedtls_des3_set2key_dec( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 2] );
/**
* \brief Triple-DES key schedule (168-bit, encryption)
*
* \param ctx 3DES context to be initialized
* \param key 24-byte secret key
*
* \return 0
*/
int mbedtls_des3_set3key_enc( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 3] );
/**
* \brief Triple-DES key schedule (168-bit, decryption)
*
* \param ctx 3DES context to be initialized
* \param key 24-byte secret key
*
* \return 0
*/
int mbedtls_des3_set3key_dec( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 3] );
/**
* \brief DES-ECB block encryption/decryption
*
* \param ctx DES context
* \param input 64-bit input block
* \param output 64-bit output block
*
* \return 0 if successful
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
int mbedtls_des_crypt_ecb( mbedtls_des_context *ctx,
const unsigned char input[8],
unsigned char output[8] );
/**
* \brief DES-CBC buffer encryption/decryption
*
* \note Upon exit, the content of the IV is updated so that you can
* call the function same function again on the following
* block(s) of data and get the same result as if it was
* encrypted in one call. This allows a "streaming" usage.
* If on the other hand you need to retain the contents of the
* IV, you should either save it manually or use the cipher
* module instead.
*
* \param ctx DES context
* \param mode MBEDTLS_DES_ENCRYPT or MBEDTLS_DES_DECRYPT
* \param length length of the input data
* \param iv initialization vector (updated after use)
* \param input buffer holding the input data
* \param output buffer holding the output data
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
int mode,
size_t length,
unsigned char iv[8],
const unsigned char *input,
unsigned char *output );
/**
* \brief 3DES-ECB block encryption/decryption
*
* \param ctx 3DES context
* \param input 64-bit input block
* \param output 64-bit output block
*
* \return 0 if successful
*/
int mbedtls_des3_crypt_ecb( mbedtls_des3_context *ctx,
const unsigned char input[8],
unsigned char output[8] );
/**
* \brief 3DES-CBC buffer encryption/decryption
*
* \note Upon exit, the content of the IV is updated so that you can
* call the function same function again on the following
* block(s) of data and get the same result as if it was
* encrypted in one call. This allows a "streaming" usage.
* If on the other hand you need to retain the contents of the
* IV, you should either save it manually or use the cipher
* module instead.
*
* \param ctx 3DES context
* \param mode MBEDTLS_DES_ENCRYPT or MBEDTLS_DES_DECRYPT
* \param length length of the input data
* \param iv initialization vector (updated after use)
* \param input buffer holding the input data
* \param output buffer holding the output data
*
* \return 0 if successful, or MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH
*/
int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
int mode,
size_t length,
unsigned char iv[8],
const unsigned char *input,
unsigned char *output );
/**
* \brief Internal function for key expansion.
* (Only exposed to allow overriding it,
* see MBEDTLS_DES_SETKEY_ALT)
*
* \param SK Round keys
* \param key Base key
*
* \warning DES is considered a weak cipher and its use constitutes a
* security risk. We recommend considering stronger ciphers
* instead.
*/
void mbedtls_des_setkey( uint32_t SK[32],
const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
#ifdef __cplusplus
}
#endif
#endif /* des.h */
des.h
/*
* FIPS-46-3 compliant Triple-DES implementation
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* DES, on which TDES is based, was originally designed by Horst Feistel
* at IBM in 1974, and was adopted as a standard by NIST (formerly NBS).
*
* http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf
*/
#include "des.h"
#include <string.h>
#include <stdio.h>
/*
* 32-bit integer manipulation macros (big endian)
*/
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i) \
{ \
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
| ( (uint32_t) (b)[(i) + 3] ); \
}
#endif
#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i) \
{ \
(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
(b)[(i) + 3] = (unsigned char) ( (n) ); \
}
#endif
/*
* Expanded DES S-boxes
*/
static const uint32_t SB1[64] =
{
0x01010400, 0x00000000, 0x00010000, 0x01010404,
0x01010004, 0x00010404, 0x00000004, 0x00010000,
0x00000400, 0x01010400, 0x01010404, 0x00000400,
0x01000404, 0x01010004, 0x01000000, 0x00000004,
0x00000404, 0x01000400, 0x01000400, 0x00010400,
0x00010400, 0x01010000, 0x01010000, 0x01000404,
0x00010004, 0x01000004, 0x01000004, 0x00010004,
0x00000000, 0x00000404, 0x00010404, 0x01000000,
0x00010000, 0x01010404, 0x00000004, 0x01010000,
0x01010400, 0x01000000, 0x01000000, 0x00000400,
0x01010004, 0x00010000, 0x00010400, 0x01000004,
0x00000400, 0x00000004, 0x01000404, 0x00010404,
0x01010404, 0x00010004, 0x01010000, 0x01000404,
0x01000004, 0x00000404, 0x00010404, 0x01010400,
0x00000404, 0x01000400, 0x01000400, 0x00000000,
0x00010004, 0x00010400, 0x00000000, 0x01010004
};
static const uint32_t SB2[64] =
{
0x80108020, 0x80008000, 0x00008000, 0x00108020,
0x00100000, 0x00000020, 0x80100020, 0x80008020,
0x80000020, 0x80108020, 0x80108000, 0x80000000,
0x80008000, 0x00100000, 0x00000020, 0x80100020,
0x00108000, 0x00100020, 0x80008020, 0x00000000,
0x80000000, 0x00008000, 0x00108020, 0x80100000,
0x00100020, 0x80000020, 0x00000000, 0x00108000,
0x00008020, 0x80108000, 0x80100000, 0x00008020,
0x00000000, 0x00108020, 0x80100020, 0x00100000,
0x80008020, 0x80100000, 0x80108000, 0x00008000,
0x80100000, 0x80008000, 0x00000020, 0x80108020,
0x00108020, 0x00000020, 0x00008000, 0x80000000,
0x00008020, 0x80108000, 0x00100000, 0x80000020,
0x00100020, 0x80008020, 0x80000020, 0x00100020,
0x00108000, 0x00000000, 0x80008000, 0x00008020,
0x80000000, 0x80100020, 0x80108020, 0x00108000
};
static const uint32_t SB3[64] =
{
0x00000208, 0x08020200, 0x00000000, 0x08020008,
0x08000200, 0x00000000, 0x00020208, 0x08000200,
0x00020008, 0x08000008, 0x08000008, 0x00020000,
0x08020208, 0x00020008, 0x08020000, 0x00000208,
0x08000000, 0x00000008, 0x08020200, 0x00000200,
0x00020200, 0x08020000, 0x08020008, 0x00020208,
0x08000208, 0x00020200, 0x00020000, 0x08000208,
0x00000008, 0x08020208, 0x00000200, 0x08000000,
0x08020200, 0x08000000, 0x00020008, 0x00000208,
0x00020000, 0x08020200, 0x08000200, 0x00000000,
0x00000200, 0x00020008, 0x08020208, 0x08000200,
0x08000008, 0x00000200, 0x00000000, 0x08020008,
0x08000208, 0x00020000, 0x08000000, 0x08020208,
0x00000008, 0x00020208, 0x00020200, 0x08000008,
0x08020000, 0x08000208, 0x00000208, 0x08020000,
0x00020208, 0x00000008, 0x08020008, 0x00020200
};
static const uint32_t SB4[64] =
{
0x00802001, 0x00002081, 0x00002081, 0x00000080,
0x00802080, 0x00800081, 0x00800001, 0x00002001,
0x00000000, 0x00802000, 0x00802000, 0x00802081,
0x00000081, 0x00000000, 0x00800080, 0x00800001,
0x00000001, 0x00002000, 0x00800000, 0x00802001,
0x00000080, 0x00800000, 0x00002001, 0x00002080,
0x00800081, 0x00000001, 0x00002080, 0x00800080,
0x00002000, 0x00802080, 0x00802081, 0x00000081,
0x00800080, 0x00800001, 0x00802000, 0x00802081,
0x00000081, 0x00000000, 0x00000000, 0x00802000,
0x00002080, 0x00800080, 0x00800081, 0x00000001,
0x00802001, 0x00002081, 0x00002081, 0x00000080,
0x00802081, 0x00000081, 0x00000001, 0x00002000,
0x00800001, 0x00002001, 0x00802080, 0x00800081,
0x00002001, 0x00002080, 0x00800000, 0x00802001,
0x00000080, 0x00800000, 0x00002000, 0x00802080
};
static const uint32_t SB5[64] =
{
0x00000100, 0x02080100, 0x02080000, 0x42000100,
0x00080000, 0x00000100, 0x40000000, 0x02080000,
0x40080100, 0x00080000, 0x02000100, 0x40080100,
0x42000100, 0x42080000, 0x00080100, 0x40000000,
0x02000000, 0x40080000, 0x40080000, 0x00000000,
0x40000100, 0x42080100, 0x42080100, 0x02000100,
0x42080000, 0x40000100, 0x00000000, 0x42000000,
0x02080100, 0x02000000, 0x42000000, 0x00080100,
0x00080000, 0x42000100, 0x00000100, 0x02000000,
0x40000000, 0x02080000, 0x42000100, 0x40080100,
0x02000100, 0x40000000, 0x42080000, 0x02080100,
0x40080100, 0x00000100, 0x02000000, 0x42080000,
0x42080100, 0x00080100, 0x42000000, 0x42080100,
0x02080000, 0x00000000, 0x40080000, 0x42000000,
0x00080100, 0x02000100, 0x40000100, 0x00080000,
0x00000000, 0x40080000, 0x02080100, 0x40000100
};
static const uint32_t SB6[64] =
{
0x20000010, 0x20400000, 0x00004000, 0x20404010,
0x20400000, 0x00000010, 0x20404010, 0x00400000,
0x20004000, 0x00404010, 0x00400000, 0x20000010,
0x00400010, 0x20004000, 0x20000000, 0x00004010,
0x00000000, 0x00400010, 0x20004010, 0x00004000,
0x00404000, 0x20004010, 0x00000010, 0x20400010,
0x20400010, 0x00000000, 0x00404010, 0x20404000,
0x00004010, 0x00404000, 0x20404000, 0x20000000,
0x20004000, 0x00000010, 0x20400010, 0x00404000,
0x20404010, 0x00400000, 0x00004010, 0x20000010,
0x00400000, 0x20004000, 0x20000000, 0x00004010,
0x20000010, 0x20404010, 0x00404000, 0x20400000,
0x00404010, 0x20404000, 0x00000000, 0x20400010,
0x00000010, 0x00004000, 0x20400000, 0x00404010,
0x00004000, 0x00400010, 0x20004010, 0x00000000,
0x20404000, 0x20000000, 0x00400010, 0x20004010
};
static const uint32_t SB7[64] =
{
0x00200000, 0x04200002, 0x04000802, 0x00000000,
0x00000800, 0x04000802, 0x00200802, 0x04200800,
0x04200802, 0x00200000, 0x00000000, 0x04000002,
0x00000002, 0x04000000, 0x04200002, 0x00000802,
0x04000800, 0x00200802, 0x00200002, 0x04000800,
0x04000002, 0x04200000, 0x04200800, 0x00200002,
0x04200000, 0x00000800, 0x00000802, 0x04200802,
0x00200800, 0x00000002, 0x04000000, 0x00200800,
0x04000000, 0x00200800, 0x00200000, 0x04000802,
0x04000802, 0x04200002, 0x04200002, 0x00000002,
0x00200002, 0x04000000, 0x04000800, 0x00200000,
0x04200800, 0x00000802, 0x00200802, 0x04200800,
0x00000802, 0x04000002, 0x04200802, 0x04200000,
0x00200800, 0x00000000, 0x00000002, 0x04200802,
0x00000000, 0x00200802, 0x04200000, 0x00000800,
0x04000002, 0x04000800, 0x00000800, 0x00200002
};
static const uint32_t SB8[64] =
{
0x10001040, 0x00001000, 0x00040000, 0x10041040,
0x10000000, 0x10001040, 0x00000040, 0x10000000,
0x00040040, 0x10040000, 0x10041040, 0x00041000,
0x10041000, 0x00041040, 0x00001000, 0x00000040,
0x10040000, 0x10000040, 0x10001000, 0x00001040,
0x00041000, 0x00040040, 0x10040040, 0x10041000,
0x00001040, 0x00000000, 0x00000000, 0x10040040,
0x10000040, 0x10001000, 0x00041040, 0x00040000,
0x00041040, 0x00040000, 0x10041000, 0x00001000,
0x00000040, 0x10040040, 0x00001000, 0x00041040,
0x10001000, 0x00000040, 0x10000040, 0x10040000,
0x10040040, 0x10000000, 0x00040000, 0x10001040,
0x00000000, 0x10041040, 0x00040040, 0x10000040,
0x10040000, 0x10001000, 0x10001040, 0x00000000,
0x10041040, 0x00041000, 0x00041000, 0x00001040,
0x00001040, 0x00040040, 0x10000000, 0x10041000
};
/*
* PC1: left and right halves bit-swap
*/
static const uint32_t LHs[16] =
{
0x00000000, 0x00000001, 0x00000100, 0x00000101,
0x00010000, 0x00010001, 0x00010100, 0x00010101,
0x01000000, 0x01000001, 0x01000100, 0x01000101,
0x01010000, 0x01010001, 0x01010100, 0x01010101
};
static const uint32_t RHs[16] =
{
0x00000000, 0x01000000, 0x00010000, 0x01010000,
0x00000100, 0x01000100, 0x00010100, 0x01010100,
0x00000001, 0x01000001, 0x00010001, 0x01010001,
0x00000101, 0x01000101, 0x00010101, 0x01010101,
};
/*
* Initial Permutation macro
*/
#define DES_IP(X,Y) \
{ \
T = ((X >> 4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T << 4); \
T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16); \
T = ((Y >> 2) ^ X) & 0x33333333; X ^= T; Y ^= (T << 2); \
T = ((Y >> 8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T << 8); \
Y = ((Y << 1) | (Y >> 31)) & 0xFFFFFFFF; \
T = (X ^ Y) & 0xAAAAAAAA; Y ^= T; X ^= T; \
X = ((X << 1) | (X >> 31)) & 0xFFFFFFFF; \
}
/*
* Final Permutation macro
*/
#define DES_FP(X,Y) \
{ \
X = ((X << 31) | (X >> 1)) & 0xFFFFFFFF; \
T = (X ^ Y) & 0xAAAAAAAA; X ^= T; Y ^= T; \
Y = ((Y << 31) | (Y >> 1)) & 0xFFFFFFFF; \
T = ((Y >> 8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T << 8); \
T = ((Y >> 2) ^ X) & 0x33333333; X ^= T; Y ^= (T << 2); \
T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16); \
T = ((X >> 4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T << 4); \
}
/*
* DES round macro
*/
#define DES_ROUND(X,Y) \
{ \
T = *SK++ ^ X; \
Y ^= SB8[ (T ) & 0x3F ] ^ \
SB6[ (T >> 8) & 0x3F ] ^ \
SB4[ (T >> 16) & 0x3F ] ^ \
SB2[ (T >> 24) & 0x3F ]; \
\
T = *SK++ ^ ((X << 28) | (X >> 4)); \
Y ^= SB7[ (T ) & 0x3F ] ^ \
SB5[ (T >> 8) & 0x3F ] ^ \
SB3[ (T >> 16) & 0x3F ] ^ \
SB1[ (T >> 24) & 0x3F ]; \
}
#define SWAP(a,b) { uint32_t t = a; a = b; b = t; t = 0; }
void mbedtls_des_init( mbedtls_des_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_des_context ) );
}
void mbedtls_des_free( mbedtls_des_context *ctx )
{
if( ctx == NULL )
return;
memset( ctx, 0, sizeof( mbedtls_des_context ) );
}
void mbedtls_des3_init( mbedtls_des3_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_des3_context ) );
}
void mbedtls_des3_free( mbedtls_des3_context *ctx )
{
if( ctx == NULL )
return;
memset( ctx, 0, sizeof( mbedtls_des3_context ) );
}
void mbedtls_des_setkey( uint32_t SK[32], const unsigned char key[MBEDTLS_DES_KEY_SIZE] )
{
int i;
uint32_t X, Y, T;
GET_UINT32_BE( X, key, 0 );
GET_UINT32_BE( Y, key, 4 );
/*
* Permuted Choice 1
*/
T = ((Y >> 4) ^ X) & 0x0F0F0F0F; X ^= T; Y ^= (T << 4);
T = ((Y ) ^ X) & 0x10101010; X ^= T; Y ^= (T );
X = (LHs[ (X ) & 0xF] << 3) | (LHs[ (X >> 8) & 0xF ] << 2)
| (LHs[ (X >> 16) & 0xF] << 1) | (LHs[ (X >> 24) & 0xF ] )
| (LHs[ (X >> 5) & 0xF] << 7) | (LHs[ (X >> 13) & 0xF ] << 6)
| (LHs[ (X >> 21) & 0xF] << 5) | (LHs[ (X >> 29) & 0xF ] << 4);
Y = (RHs[ (Y >> 1) & 0xF] << 3) | (RHs[ (Y >> 9) & 0xF ] << 2)
| (RHs[ (Y >> 17) & 0xF] << 1) | (RHs[ (Y >> 25) & 0xF ] )
| (RHs[ (Y >> 4) & 0xF] << 7) | (RHs[ (Y >> 12) & 0xF ] << 6)
| (RHs[ (Y >> 20) & 0xF] << 5) | (RHs[ (Y >> 28) & 0xF ] << 4);
X &= 0x0FFFFFFF;
Y &= 0x0FFFFFFF;
/*
* calculate subkeys
*/
for( i = 0; i < 16; i++ )
{
if( i < 2 || i == 8 || i == 15 )
{
X = ((X << 1) | (X >> 27)) & 0x0FFFFFFF;
Y = ((Y << 1) | (Y >> 27)) & 0x0FFFFFFF;
}
else
{
X = ((X << 2) | (X >> 26)) & 0x0FFFFFFF;
Y = ((Y << 2) | (Y >> 26)) & 0x0FFFFFFF;
}
*SK++ = ((X << 4) & 0x24000000) | ((X << 28) & 0x10000000)
| ((X << 14) & 0x08000000) | ((X << 18) & 0x02080000)
| ((X << 6) & 0x01000000) | ((X << 9) & 0x00200000)
| ((X >> 1) & 0x00100000) | ((X << 10) & 0x00040000)
| ((X << 2) & 0x00020000) | ((X >> 10) & 0x00010000)
| ((Y >> 13) & 0x00002000) | ((Y >> 4) & 0x00001000)
| ((Y << 6) & 0x00000800) | ((Y >> 1) & 0x00000400)
| ((Y >> 14) & 0x00000200) | ((Y ) & 0x00000100)
| ((Y >> 5) & 0x00000020) | ((Y >> 10) & 0x00000010)
| ((Y >> 3) & 0x00000008) | ((Y >> 18) & 0x00000004)
| ((Y >> 26) & 0x00000002) | ((Y >> 24) & 0x00000001);
*SK++ = ((X << 15) & 0x20000000) | ((X << 17) & 0x10000000)
| ((X << 10) & 0x08000000) | ((X << 22) & 0x04000000)
| ((X >> 2) & 0x02000000) | ((X << 1) & 0x01000000)
| ((X << 16) & 0x00200000) | ((X << 11) & 0x00100000)
| ((X << 3) & 0x00080000) | ((X >> 6) & 0x00040000)
| ((X << 15) & 0x00020000) | ((X >> 4) & 0x00010000)
| ((Y >> 2) & 0x00002000) | ((Y << 8) & 0x00001000)
| ((Y >> 14) & 0x00000808) | ((Y >> 9) & 0x00000400)
| ((Y ) & 0x00000200) | ((Y << 7) & 0x00000100)
| ((Y >> 7) & 0x00000020) | ((Y >> 3) & 0x00000011)
| ((Y << 2) & 0x00000004) | ((Y >> 21) & 0x00000002);
}
}
/*
* DES key schedule (56-bit, encryption)
*/
int mbedtls_des_setkey_enc( mbedtls_des_context *ctx, const unsigned char key[MBEDTLS_DES_KEY_SIZE] )
{
mbedtls_des_setkey( ctx->sk, key );
return( 0 );
}
/*
* DES key schedule (56-bit, decryption)
*/
int mbedtls_des_setkey_dec( mbedtls_des_context *ctx, const unsigned char key[MBEDTLS_DES_KEY_SIZE] )
{
int i;
mbedtls_des_setkey( ctx->sk, key );
for( i = 0; i < 16; i += 2 )
{
SWAP( ctx->sk[i ], ctx->sk[30 - i] );
SWAP( ctx->sk[i + 1], ctx->sk[31 - i] );
}
return( 0 );
}
static void des3_set2key( uint32_t esk[96],
uint32_t dsk[96],
const unsigned char key[MBEDTLS_DES_KEY_SIZE*2] )
{
int i;
mbedtls_des_setkey( esk, key );
mbedtls_des_setkey( dsk + 32, key + 8 );
for( i = 0; i < 32; i += 2 )
{
dsk[i ] = esk[30 - i];
dsk[i + 1] = esk[31 - i];
esk[i + 32] = dsk[62 - i];
esk[i + 33] = dsk[63 - i];
esk[i + 64] = esk[i ];
esk[i + 65] = esk[i + 1];
dsk[i + 64] = dsk[i ];
dsk[i + 65] = dsk[i + 1];
}
}
/*
* Triple-DES key schedule (112-bit, encryption)
*/
int mbedtls_des3_set2key_enc( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 2] )
{
uint32_t sk[96];
des3_set2key( ctx->sk, sk, key );
memset( sk, 0, sizeof( sk ) );
return( 0 );
}
/*
* Triple-DES key schedule (112-bit, decryption)
*/
int mbedtls_des3_set2key_dec( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 2] )
{
uint32_t sk[96];
des3_set2key( sk, ctx->sk, key );
memset( sk, 0, sizeof( sk ) );
return( 0 );
}
static void des3_set3key( uint32_t esk[96],
uint32_t dsk[96],
const unsigned char key[24] )
{
int i;
mbedtls_des_setkey( esk, key );
mbedtls_des_setkey( dsk + 32, key + 8 );
mbedtls_des_setkey( esk + 64, key + 16 );
for( i = 0; i < 32; i += 2 )
{
dsk[i ] = esk[94 - i];
dsk[i + 1] = esk[95 - i];
esk[i + 32] = dsk[62 - i];
esk[i + 33] = dsk[63 - i];
dsk[i + 64] = esk[30 - i];
dsk[i + 65] = esk[31 - i];
}
}
/*
* Triple-DES key schedule (168-bit, encryption)
*/
int mbedtls_des3_set3key_enc( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 3] )
{
uint32_t sk[96];
des3_set3key( ctx->sk, sk, key );
memset( sk, 0, sizeof( sk ) );
return( 0 );
}
/*
* Triple-DES key schedule (168-bit, decryption)
*/
int mbedtls_des3_set3key_dec( mbedtls_des3_context *ctx,
const unsigned char key[MBEDTLS_DES_KEY_SIZE * 3] )
{
uint32_t sk[96];
des3_set3key( sk, ctx->sk, key );
memset( sk, 0, sizeof( sk ) );
return( 0 );
}
/*
* DES-ECB block encryption/decryption
*/
int mbedtls_des_crypt_ecb( mbedtls_des_context *ctx,
const unsigned char input[8],
unsigned char output[8] )
{
int i;
uint32_t X, Y, T, *SK;
SK = ctx->sk;
GET_UINT32_BE( X, input, 0 );
GET_UINT32_BE( Y, input, 4 );
DES_IP( X, Y );
for( i = 0; i < 8; i++ )
{
DES_ROUND( Y, X );
DES_ROUND( X, Y );
}
DES_FP( Y, X );
PUT_UINT32_BE( Y, output, 0 );
PUT_UINT32_BE( X, output, 4 );
return( 0 );
}
/*
* DES-CBC buffer encryption/decryption
*/
int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
int mode,
size_t length,
unsigned char iv[8],
const unsigned char *input,
unsigned char *output )
{
int i;
unsigned char temp[8];
if( length % 8 )
return( MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH );
if( mode == MBEDTLS_DES_ENCRYPT )
{
while( length > 0 )
{
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( input[i] ^ iv[i] );
mbedtls_des_crypt_ecb( ctx, output, output );
memcpy( iv, output, 8 );
input += 8;
output += 8;
length -= 8;
}
}
else /* MBEDTLS_DES_DECRYPT */
{
while( length > 0 )
{
memcpy( temp, input, 8 );
mbedtls_des_crypt_ecb( ctx, input, output );
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( output[i] ^ iv[i] );
memcpy( iv, temp, 8 );
input += 8;
output += 8;
length -= 8;
}
}
return( 0 );
}
/*
* 3DES-ECB block encryption/decryption
*/
int mbedtls_des3_crypt_ecb( mbedtls_des3_context *ctx,
const unsigned char input[8],
unsigned char output[8] )
{
int i;
uint32_t X, Y, T, *SK;
SK = ctx->sk;
GET_UINT32_BE( X, input, 0 );
GET_UINT32_BE( Y, input, 4 );
DES_IP( X, Y );
for( i = 0; i < 8; i++ )
{
DES_ROUND( Y, X );
DES_ROUND( X, Y );
}
for( i = 0; i < 8; i++ )
{
DES_ROUND( X, Y );
DES_ROUND( Y, X );
}
for( i = 0; i < 8; i++ )
{
DES_ROUND( Y, X );
DES_ROUND( X, Y );
}
DES_FP( Y, X );
PUT_UINT32_BE( Y, output, 0 );
PUT_UINT32_BE( X, output, 4 );
return( 0 );
}
/*
* 3DES-CBC buffer encryption/decryption
*/
int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
int mode,
size_t length,
unsigned char iv[8],
const unsigned char *input,
unsigned char *output )
{
int i;
unsigned char temp[8];
if( length % 8 )
return( MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH );
if( mode == MBEDTLS_DES_ENCRYPT )
{
while( length > 0 )
{
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( input[i] ^ iv[i] );
mbedtls_des3_crypt_ecb( ctx, output, output );
memcpy( iv, output, 8 );
input += 8;
output += 8;
length -= 8;
}
}
else /* MBEDTLS_DES_DECRYPT */
{
while( length > 0 )
{
memcpy( temp, input, 8 );
mbedtls_des3_crypt_ecb( ctx, input, output );
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( output[i] ^ iv[i] );
memcpy( iv, temp, 8 );
input += 8;
output += 8;
length -= 8;
}
}
return( 0 );
}
base64.h
#ifndef BASE64_H
#define BASE64_H
#define BASE64_ENCODE_OUT_SIZE(s) ((unsigned int)((((s) + 2) / 3) * 4 + 1))
#define BASE64_DECODE_OUT_SIZE(s) ((unsigned int)(((s) / 4) * 3))
#ifdef __cplusplus
extern "C" {
#endif
/*
* out is null-terminated encode string.
* return values is out length, exclusive terminating `\0'
*/
unsigned int
base64_encode(const unsigned char *in, unsigned int inlen, char *out);
/*
* return values is out length
*/
unsigned int
base64_decode(const char *in, unsigned int inlen, unsigned char *out);
#ifdef __cplusplus
}
#endif
#endif /* BASE64_H */
base64.c
/* This is a public domain base64 implementation written by WEI Zhicheng. */
#include "base64.h"
#define BASE64_PAD '='
/* BASE 64 encode table */
static const char base64en[] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/',
};
/* ASCII order for BASE 64 decode, 255 in unused character */
static const unsigned char base64de[] = {
/* nul, soh, stx, etx, eot, enq, ack, bel, */
255, 255, 255, 255, 255, 255, 255, 255,
/* bs, ht, nl, vt, np, cr, so, si, */
255, 255, 255, 255, 255, 255, 255, 255,
/* dle, dc1, dc2, dc3, dc4, nak, syn, etb, */
255, 255, 255, 255, 255, 255, 255, 255,
/* can, em, sub, esc, fs, gs, rs, us, */
255, 255, 255, 255, 255, 255, 255, 255,
/* sp, '!', '"', '#', '$', '%', '&', ''', */
255, 255, 255, 255, 255, 255, 255, 255,
/* '(', ')', '*', '+', ',', '-', '.', '/', */
255, 255, 255, 62, 255, 255, 255, 63,
/* '0', '1', '2', '3', '4', '5', '6', '7', */
52, 53, 54, 55, 56, 57, 58, 59,
/* '8', '9', ':', ';', '<', '=', '>', '?', */
60, 61, 255, 255, 255, 255, 255, 255,
/* '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G', */
255, 0, 1, 2, 3, 4, 5, 6,
/* 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', */
7, 8, 9, 10, 11, 12, 13, 14,
/* 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', */
15, 16, 17, 18, 19, 20, 21, 22,
/* 'X', 'Y', 'Z', '[', '\', ']', '^', '_', */
23, 24, 25, 255, 255, 255, 255, 255,
/* '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', */
255, 26, 27, 28, 29, 30, 31, 32,
/* 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', */
33, 34, 35, 36, 37, 38, 39, 40,
/* 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', */
41, 42, 43, 44, 45, 46, 47, 48,
/* 'x', 'y', 'z', '{', '|', '}', '~', del, */
49, 50, 51, 255, 255, 255, 255, 255
};
unsigned int
base64_encode(const unsigned char *in, unsigned int inlen, char *out)
{
int s;
unsigned int i;
unsigned int j;
unsigned char c;
unsigned char l;
s = 0;
l = 0;
for (i = j = 0; i < inlen; i++) {
c = in[i];
switch (s) {
case 0:
s = 1;
out[j++] = base64en[(c >> 2) & 0x3F];
break;
case 1:
s = 2;
out[j++] = base64en[((l & 0x3) << 4) | ((c >> 4) & 0xF)];
break;
case 2:
s = 0;
out[j++] = base64en[((l & 0xF) << 2) | ((c >> 6) & 0x3)];
out[j++] = base64en[c & 0x3F];
break;
}
l = c;
}
switch (s) {
case 1:
out[j++] = base64en[(l & 0x3) << 4];
out[j++] = BASE64_PAD;
out[j++] = BASE64_PAD;
break;
case 2:
out[j++] = base64en[(l & 0xF) << 2];
out[j++] = BASE64_PAD;
break;
}
out[j] = 0;
return j;
}
unsigned int
base64_decode(const char *in, unsigned int inlen, unsigned char *out)
{
unsigned int i;
unsigned int j;
unsigned char c;
if (inlen & 0x3) {
return 0;
}
for (i = j = 0; i < inlen; i++) {
if (in[i] == BASE64_PAD) {
break;
}
if (in[i] < 0) {
return 0;
}
c = base64de[in[i]];
if (c == 255) {
return 0;
}
switch (i & 0x3) {
case 0:
out[j] = (c << 2) & 0xFF;
break;
case 1:
out[j++] |= (c >> 4) & 0x3;
out[j] = (c & 0xF) << 4;
break;
case 2:
out[j++] |= (c >> 2) & 0xF;
out[j] = (c & 0x3) << 6;
break;
case 3:
out[j++] |= c;
break;
}
}
out[j] = '\0';
return j;
}
觉得好,就一键三连呗(点赞+收藏+关注)
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