AES 128 加密补充

上篇的博客主要写加密解密，但是具体的代码没有直接的写出来。下边我吧具体的写出来，供大家参考。

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <stdio.h>                      /* Standard I/O .h-file               */
#include <ctype.h>                      /* Character functions                */
#include <string.h>                     /* String and memory functions        */
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "stm32f0xx.h"
#include "stm32f0xx_conf.h"
#include "AES.h"
#include "Serial.h"
#include "Mcu_config.h"


// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4


// The number of rounds in AES Cipher. It is simply initiated to zero. The actual value is recieved in the program.
int Nr=0;


// The number of 32 bit words in the key. It is simply initiated to zero. The actual value is recieved in the program.
int Nk=0;


//Nc: the length of Key(128, 192 or 256) only
int Nc = 128;


// in - it is the array that holds the CipherText to be decrypted.
// out - it is the array that holds the output of the for decryption.
// state - the array that holds the intermediate results during decryption.
unsigned char in[16], out[32], state[4][4];


// The array that stores the round keys.
unsigned char RoundKey[RoundKeyLEN];


// The Key input to the AES Program
unsigned char Key[32];


#define AES_TEMP_BUFF_LEN 1024




const uint8_t rsbox[256] =
{ 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb
, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb
, 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e
, 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25
, 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92
, 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84
, 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06
, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b
, 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73
, 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e
, 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b
, 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4
, 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f
, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef
, 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61
, 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };
uint8_t getSBoxInvert(uint8_t num)
{
return rsbox[num];
}
const uint8_t sbox[256] =   {
    //0     1    2      3     4    5     6     7      8    9     A      B    C     D     E     F
    0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
    0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
    0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
    0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
    0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
    0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
    0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
    0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
    0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
    0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
    0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
    0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
    0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
    0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
    0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
    0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
uint8_t getSBoxValue(uint8_t num)
{
    return sbox[num];
}


// The round constant word array, Rcon[i], contains the values given by 
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
// Note that i starts at 1, not 0).
const uint8_t Rcon[255] = {
    0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 
    0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 
    0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 
    0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 
    0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 
    0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 
    0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 
    0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 
    0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 
    0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 
    0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 
    0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 
    0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 
    0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 
    0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 
    0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb  };


// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. 
void KeyExpansion()
{
    int i,j;
    unsigned char temp[4],k;
    
    // The first round key is the key itself.
    for(i=0;i<Nk;i++)
    {
        RoundKey[i*4]=Key[i*4];
        RoundKey[i*4+1]=Key[i*4+1];
        RoundKey[i*4+2]=Key[i*4+2];
        RoundKey[i*4+3]=Key[i*4+3];
    }


    // All other round keys are found from the previous round keys.
    while (i < (Nb * (Nr+1)))
    {
        for(j=0;j<4;j++)
        {
            temp[j]=RoundKey[(i-1) * 4 + j];
        }
        if (i % Nk == 0)
        {
            // This function rotates the 4 bytes in a word to the left once.
            // [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
            {
                k = temp[0];
                temp[0] = temp[1];
                temp[1] = temp[2];
                temp[2] = temp[3];
                temp[3] = k;
            }


            // SubWord() is a function that takes a four-byte input word and 
            // applies the S-box to each of the four bytes to produce an output word.
            {
                temp[0]=getSBoxValue(temp[0]);
                temp[1]=getSBoxValue(temp[1]);
                temp[2]=getSBoxValue(temp[2]);
                temp[3]=getSBoxValue(temp[3]);
            }


            temp[0] =  temp[0] ^ Rcon[i/Nk];
        }
        else if (Nk > 6 && i % Nk == 4)
        {
            {
                temp[0]=getSBoxValue(temp[0]);
                temp[1]=getSBoxValue(temp[1]);
                temp[2]=getSBoxValue(temp[2]);
                temp[3]=getSBoxValue(temp[3]);
            }
        }
        RoundKey[i*4+0] = RoundKey[(i-Nk)*4+0] ^ temp[0];
        RoundKey[i*4+1] = RoundKey[(i-Nk)*4+1] ^ temp[1];
        RoundKey[i*4+2] = RoundKey[(i-Nk)*4+2] ^ temp[2];
        RoundKey[i*4+3] = RoundKey[(i-Nk)*4+3] ^ temp[3];
        i++;
    }
}


// This function adds the round key to state.
// The round key is added to the state by an XOR function.
void AddRoundKey(int round) 
{
    int i,j;
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            state[j][i] ^= RoundKey[round * Nb * 4 + i * Nb + j];
        }
    }
}


// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
void InvSubBytes()
{
    int i,j;
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            state[i][j] = getSBoxInvert(state[i][j]);


        }
    }
}


// The ShiftRows() function shifts the rows in the state to the left.
// Each row is shifted with different offset.
// Offset = Row number. So the first row is not shifted.
void InvShiftRows()
{
    unsigned char temp;


    // Rotate first row 1 columns to right    
    temp=state[1][3];
    state[1][3]=state[1][2];
    state[1][2]=state[1][1];
    state[1][1]=state[1][0];
    state[1][0]=temp;


    // Rotate second row 2 columns to right    
    temp=state[2][0];
    state[2][0]=state[2][2];
    state[2][2]=temp;


    temp=state[2][1];
    state[2][1]=state[2][3];
    state[2][3]=temp;


    // Rotate third row 3 columns to right
    temp=state[3][0];
    state[3][0]=state[3][1];
    state[3][1]=state[3][2];
    state[3][2]=state[3][3];
    state[3][3]=temp;
}


// xtime is a macro that finds the product of {02} and the argument to xtime modulo {1b}  
#define xtime(x)   ((x<<1) ^ (((x>>7) & 1) * 0x1b))


// Multiplty is a macro used to multiply numbers in the field GF(2^8)
#define Multiply(x,y) (((y & 1) * x) ^ ((y>>1 & 1) * xtime(x)) ^ ((y>>2 & 1) * xtime(xtime(x))) ^ ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ ((y>>4 & 1) * xtime(xtime(xtime(xtime(x))))))


// MixColumns function mixes the columns of the state matrix.
// The method used to multiply may be difficult to understand for the inexperienced.
// Please use the references to gain more information.
void InvMixColumns()
{
    int i;
    unsigned char a,b,c,d;
    for(i=0;i<4;i++)
    {    
    
        a = state[0][i];
        b = state[1][i];
        c = state[2][i];
        d = state[3][i];


        
        state[0][i] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
        state[1][i] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
        state[2][i] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
        state[3][i] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
    }
}


// InvCipher is the main function that decrypts the CipherText.
void InvCipher()
{
    int i,j,round=0;


    //Copy the input CipherText to state array.
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            state[j][i] = in[i*4 + j];
        }
    }


    // Add the First round key to the state before starting the rounds.
    AddRoundKey(Nr); 


    // There will be Nr rounds.
    // The first Nr-1 rounds are identical.
    // These Nr-1 rounds are executed in the loop below.
    for(round=Nr-1;round>0;round--)
    {
        InvShiftRows();
        InvSubBytes();
        AddRoundKey(round);
        InvMixColumns();
    }
    
    // The last round is given below.
    // The MixColumns function is not here in the last round.
    InvShiftRows();
    InvSubBytes();
    AddRoundKey(0);


    // The decryption process is over.
    // Copy the state array to output array.
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            out[i*4+j]=state[j][i];
        }
    }
}


// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
void SubBytes()
{
    int i,j;
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            state[i][j] = getSBoxValue(state[i][j]);


        }
    }
}


// The ShiftRows() function shifts the rows in the state to the left.
// Each row is shifted with different offset.
// Offset = Row number. So the first row is not shifted.
void ShiftRows()
{
    unsigned char temp;


    // Rotate first row 1 columns to left    
    temp=state[1][0];
    state[1][0]=state[1][1];
    state[1][1]=state[1][2];
    state[1][2]=state[1][3];
    state[1][3]=temp;


    // Rotate second row 2 columns to left    
    temp=state[2][0];
    state[2][0]=state[2][2];
    state[2][2]=temp;


    temp=state[2][1];
    state[2][1]=state[2][3];
    state[2][3]=temp;


    // Rotate third row 3 columns to left
    temp=state[3][0];
    state[3][0]=state[3][3];
    state[3][3]=state[3][2];
    state[3][2]=state[3][1];
    state[3][1]=temp;
}


// xtime is a macro that finds the product of {02} and the argument to xtime modulo {1b}  
#define xtime(x)   ((x<<1) ^ (((x>>7) & 1) * 0x1b))


// MixColumns function mixes the columns of the state matrix
void MixColumns()
{
    int i;
    unsigned char Tmp,Tm,t;
    for(i=0;i<4;i++)
    {    
        t=state[0][i];
        Tmp = state[0][i] ^ state[1][i] ^ state[2][i] ^ state[3][i] ;
        Tm = state[0][i] ^ state[1][i] ; Tm = xtime(Tm); state[0][i] ^= Tm ^ Tmp ;
        Tm = state[1][i] ^ state[2][i] ; Tm = xtime(Tm); state[1][i] ^= Tm ^ Tmp ;
        Tm = state[2][i] ^ state[3][i] ; Tm = xtime(Tm); state[2][i] ^= Tm ^ Tmp ;
        Tm = state[3][i] ^ t ; Tm = xtime(Tm); state[3][i] ^= Tm ^ Tmp ;
    }
}


// Cipher is the main function that encrypts the PlainText.
void Cipher()
{
    int i,j,round=0;


    //Copy the input PlainText to state array.
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            state[j][i] = in[i*4 + j];
        }
    }


    // Add the First round key to the state before starting the rounds.
    AddRoundKey(0); 
    
    // There will be Nr rounds.
    // The first Nr-1 rounds are identical.
    // These Nr-1 rounds are executed in the loop below.
    for(round=1;round<Nr;round++)
    {
        SubBytes();
        ShiftRows();
        MixColumns();
        AddRoundKey(round);
    }
    
    // The last round is given below.
    // The MixColumns function is not here in the last round.
    SubBytes();
    ShiftRows();
    AddRoundKey(Nr);


    // The encryption process is over.
    // Copy the state array to output array.
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            out[i*4+j]=state[j][i];
        }
    }
}


char *encrypt(char *str, char *key) 
{
    int i,j,Nl;
int len;
char *newstr;


    Nk = Nc / 32;
    Nr = Nk + 6;
    
    len= strlen(str);
    Nl = (int)ceil(len / 16);      
  
    newstr = (char *)malloc(Nl*32);


    //memset(newstr,0,sizeof(newstr));
    memset(newstr,0,Nl*32);
 
    for(i=0;i<Nl;i++)
    {
        for(j=0;j<Nk*4;j++)
        {
            Key[j]=key[j];
            in[j]=str[i*16+j];
        }
        
        KeyExpansion();
        Cipher();
memcpy(newstr+16*i, out, 16);
        //strcat(newstr,out);
    }
    return newstr;
}




char *decrypt(char *str, char *key , int len) 
{
    int i,j,Nl;
char *newstr;


    Nk = Nc / 32;
    Nr = Nk + 6;
    
    //len= strlen(str);
    Nl = (int)ceil(len / 16);
     
    newstr = (char *)malloc(16*Nl);
    //memset(newstr,0,sizeof(newstr));
    memset(newstr,0,16*Nl);

    for(i=0;i<Nl;i++)
    {
        for(j=0;j<Nk*4;j++)
        {
            Key[j]=key[j];
            in[j]=str[i*16+j];
        }
        
        KeyExpansion();
        InvCipher();
memcpy(newstr+16*i, out, 16);
        //strcat(newstr,out);
    }
    return newstr;
}
//////////////////////////////////////////////////////////////////////////////////////////
//Base64 ??


int Base64Encode( char *OrgString, char *Base64String, int OrgStringLen ) 
{
// OrgString ????????
// Base64String ???????????
// OrgStringLen ????????
static char Base64Encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int Base64StringLen = 0;


while( OrgStringLen > 0 )
{
*Base64String ++ = Base64Encode[(OrgString[0] >> 2 ) & 0x3f];
if( OrgStringLen > 2 )
{
*Base64String ++ = Base64Encode[((OrgString[0] & 3) << 4) | (OrgString[1] >> 4)];
*Base64String ++ = Base64Encode[((OrgString[1] & 0xF) << 2) | (OrgString[2] >> 6)];
*Base64String ++ = Base64Encode[OrgString[2] & 0x3F];
}
else
{
switch( OrgStringLen )
{
case 1:
*Base64String ++ = Base64Encode[(OrgString[0] & 3) << 4 ];
*Base64String ++ = '=';
*Base64String ++ = '=';
break;
case 2:
*Base64String ++ = Base64Encode[((OrgString[0] & 3) << 4) | (OrgString[1] >> 4)];
*Base64String ++ = Base64Encode[((OrgString[1] & 0x0F) << 2) | (OrgString[2] >> 6)];
*Base64String ++ = '=';
break;
}
}

OrgString +=3;
OrgStringLen -=3;
Base64StringLen +=4;
}


*Base64String = 0;
return Base64StringLen;
}
//////////////////////////////////////////////////////////////////////////////////////////
//Base64 ??
char GetBase64Value(char ch) //?????
{
if ((ch >= 'A') && (ch <= 'Z'))  // A ~ Z
return ch - 'A';
if ((ch >= 'a') && (ch <= 'z'))  // a ~ z
return ch - 'a' + 26;
if ((ch >= '0') && (ch <= '9'))  // 0 ~ 9
return ch - '0' + 52;
switch (ch)       // ????
{
case '+':
return 62;
case '/':
return 63;
case '=':  //Base64 ????
return 0;
default:
return 0;
}
}
// ????
int Base64Decode( char *OrgString, char *Base64String, int Base64StringLen, bool bForceDecode )  //????
{
// OrgString ???????????
// Base64String ????????
// Base64StringLen ????????
// bForceDecode ????????????,??????
//     true  ????
//     false ?????
unsigned char Base64Encode[4];
unsigned char denghaoNum = 0;
unsigned char i;
int OrgStringLen=0;
if( Base64StringLen % 4 && !bForceDecode )   //???? 4 ???,? Base64 ?????
{
OrgString[0] = '\0';
return -1;
}
for (i=Base64StringLen-1; i>0; i--)
{
if (Base64String[i] == '=')
denghaoNum++;
else
break;
}




while( Base64StringLen > 2 )  
{
Base64Encode[0] = GetBase64Value(Base64String[0]);
Base64Encode[1] = GetBase64Value(Base64String[1]);
Base64Encode[2] = GetBase64Value(Base64String[2]);
Base64Encode[3] = GetBase64Value(Base64String[3]);

*OrgString ++ = (Base64Encode[0] << 2) | (Base64Encode[1] >> 4);
*OrgString ++ = (Base64Encode[1] << 4) | (Base64Encode[2] >> 2);
*OrgString ++ = (Base64Encode[2] << 6) | (Base64Encode[3]);

Base64String += 4;
Base64StringLen -= 4;
OrgStringLen += 3;
}

return OrgStringLen-denghaoNum;
}


/*
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*/
void AES_Encrypt(char* pExpressText , char* pCipherText  , char* pAeskey)
{
char* str;
uint8_t buWei;
uint16_t aesDataLen;  //待加密的数据长度


aesDataLen = strlen(pExpressText);
buWei = 16-aesDataLen%16;
memset(pExpressText+aesDataLen , buWei, buWei);

aesDataLen = strlen(pExpressText);
//pExpressText:待加密的明文数据，pkey：加密密钥  str：加密后的数据
str = encrypt(pExpressText, pAeskey);  //aesTempBuff[AES_TEMP_BUFF_LEN]

UART_Printf ("encrypt result:  ");
UART_Printf (str);
  UART_Printf ("\r\n");


//str:待编码的数据  pCipherText：编码后的数据  aesDataLen：待编码的长度
Base64Encode(str, pCipherText,aesDataLen);
free(str);
  UART_Printf("Base64 encoded result:  ");
UART_Printf(pCipherText);
  UART_Printf("\r\n");


}


/*
欢迎加入
二手开发板供求交易群  68936520
arm交流学习群    324753668
stm32交流学习群  227043677
*/
void AES_Decrypt(char* pExpressText , char* pCipherText , char* pAeskey)
{
char* str2;
uint8_t buIndex , i;
uint16_t aesDataLen;  //待解密的数据长度
char *newstr;

aesDataLen = strlen(pCipherText);
newstr = (char *)malloc(aesDataLen);
memset(newstr , 0 , aesDataLen);
aesDataLen = Base64Decode(newstr , pCipherText, aesDataLen, true);

  UART_Printf("decoded result:  ");
  UART_Printf(newstr);
  UART_Printf("\r\n");


//send_buff：待解密的数据  ，pkey：密钥   str2：解密后的数据
  str2 = decrypt(newstr, pAeskey , aesDataLen);
free(newstr);
//去除末尾补码
buIndex = str2[aesDataLen-1];


for(i=0; i<buIndex; i++)
{
if(str2[aesDataLen-i-1] != buIndex)
{
UART_Printf("\nit is a wrong data. \n");
free(str2);
return;
}
else
str2[aesDataLen-i-1] = '\0';
}
strcpy(pExpressText , str2);
free(str2);

  UART_Printf ("AES decrypt result:  ");
  UART_Printf (pExpressText);
  UART_Printf ("\r\n");
}

上边的代码已经实现AES的加密解密，大家直接复制就行，在STM32单片机里直接调用就行。