RITESH REDDY SADULA / Mbed 2 deprecated Encrypt_Decrypt1

Ritesh

Dependencies:   mbed mbedtls

main.cpp@0:20df98087dc9, 2017-05-05 (annotated)

Committer:
ritesh2094
Date:
Fri May 05 20:14:32 2017 +0000
Revision:
0:20df98087dc9
Encrypt_Decrypt1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ritesh2094 0:20df98087dc9 1 #include "mbed.h"
ritesh2094 0:20df98087dc9 2
ritesh2094 0:20df98087dc9 3 //------------------------------------
ritesh2094 0:20df98087dc9 4 // Hyperterminal configuration
ritesh2094 0:20df98087dc9 5 // 9600 bauds, 8-bit data, no parity
ritesh2094 0:20df98087dc9 6 //------------------------------------
ritesh2094 0:20df98087dc9 7
ritesh2094 0:20df98087dc9 8 #include "mbedtls/aes.h"
ritesh2094 0:20df98087dc9 9
ritesh2094 0:20df98087dc9 10 #define IV_SIZE 16
ritesh2094 0:20df98087dc9 11 #define INPUT_SIZE 256
ritesh2094 0:20df98087dc9 12
ritesh2094 0:20df98087dc9 13 Serial pc(USBTX, USBRX);
ritesh2094 0:20df98087dc9 14
ritesh2094 0:20df98087dc9 15 // Indicator LED
ritesh2094 0:20df98087dc9 16 DigitalOut myled(LED1);
ritesh2094 0:20df98087dc9 17
ritesh2094 0:20df98087dc9 18 // This function initializes the initilization vector to the original one.
ritesh2094 0:20df98087dc9 19 void init_ivs(unsigned char iv_orig[], unsigned char iv1[], unsigned char iv2[]);
ritesh2094 0:20df98087dc9 20
ritesh2094 0:20df98087dc9 21
ritesh2094 0:20df98087dc9 22 int main()
ritesh2094 0:20df98087dc9 23 {
ritesh2094 0:20df98087dc9 24 int i=0;
ritesh2094 0:20df98087dc9 25
ritesh2094 0:20df98087dc9 26 // We create two AES contexts
ritesh2094 0:20df98087dc9 27 mbedtls_aes_context aes;
ritesh2094 0:20df98087dc9 28 mbedtls_aes_context aes2;
ritesh2094 0:20df98087dc9 29
ritesh2094 0:20df98087dc9 30 // Our KEY , should be shared only with the receiver and has to be as random as possible.
ritesh2094 0:20df98087dc9 31 // Here we use this simple example for ease and simplicity
ritesh2094 0:20df98087dc9 32 unsigned char key[32] = "1234567812345678123456781234567" ;
ritesh2094 0:20df98087dc9 33 key[31] = '8'; // we replace the 32th (index 31) which contains '/0' with the '8' char.
ritesh2094 0:20df98087dc9 34
ritesh2094 0:20df98087dc9 35 // This is the Init Vector generated with the random KEY from http://aes.online-domain-tools.com/
ritesh2094 0:20df98087dc9 36 unsigned char orig_iv[] = {0x8d, 0xf8, 0x4d, 0xed, 0x5f, 0xbd, 0x51, 0x57, 0x5c, 0x55, 0x17, 0xb0, 0x66, 0xee, 0xb1, 0x2b}; // e053a4a22fd6bfaf43fd5e8b5"; {0xb2, 0x4b, 0xf2, 0xf7, 0x7a, 0xc5, 0xec, 0x0c, 0x5e, 0x1f, 0x4d, 0xc1, 0xae, 0x46, 0x5e, 0x75};
ritesh2094 0:20df98087dc9 37 unsigned char iv1[IV_SIZE] = {0};
ritesh2094 0:20df98087dc9 38 unsigned char iv2[IV_SIZE] = {0};
ritesh2094 0:20df98087dc9 39
ritesh2094 0:20df98087dc9 40 // This is the text that we want to encrypt and send
ritesh2094 0:20df98087dc9 41 unsigned char my_txt[] = "My name is Ritesh Reddy Sadula";
ritesh2094 0:20df98087dc9 42
ritesh2094 0:20df98087dc9 43 unsigned char input[INPUT_SIZE] = {0};
ritesh2094 0:20df98087dc9 44
ritesh2094 0:20df98087dc9 45 for(int m=0; m<strlen((const char*)my_txt); m++)
ritesh2094 0:20df98087dc9 46 {
ritesh2094 0:20df98087dc9 47 input[m] = *(my_txt+m);
ritesh2094 0:20df98087dc9 48 }
ritesh2094 0:20df98087dc9 49
ritesh2094 0:20df98087dc9 50
ritesh2094 0:20df98087dc9 51 // Output of encryption
ritesh2094 0:20df98087dc9 52 unsigned char output[INPUT_SIZE] = {0};
ritesh2094 0:20df98087dc9 53 // Output of decryption
ritesh2094 0:20df98087dc9 54 unsigned char output2[INPUT_SIZE] = {0};
ritesh2094 0:20df98087dc9 55
ritesh2094 0:20df98087dc9 56 int ret =0;
ritesh2094 0:20df98087dc9 57
ritesh2094 0:20df98087dc9 58 // To be a valid length, it has to be a multiple of 16, so we take the muliple of 16 that is nearly bigger than the actual size
ritesh2094 0:20df98087dc9 59 // Or the
ritesh2094 0:20df98087dc9 60 int TXT_VALID_LENGTH = ((strlen((const char*)my_txt)%16 == 0) ? strlen((const char*)my_txt) : (strlen((const char*)my_txt)/16 + 1)*16);
ritesh2094 0:20df98087dc9 61 while(1){
ritesh2094 0:20df98087dc9 62 init_ivs(orig_iv , iv1, iv2);
ritesh2094 0:20df98087dc9 63
ritesh2094 0:20df98087dc9 64
ritesh2094 0:20df98087dc9 65 mbedtls_aes_setkey_enc( &aes, key, 256);
ritesh2094 0:20df98087dc9 66 ret = mbedtls_aes_crypt_cbc( &aes, MBEDTLS_AES_ENCRYPT, TXT_VALID_LENGTH, iv1, input, output );
ritesh2094 0:20df98087dc9 67 pc.printf("%d - Ret: %d - strlen(input)=%d - ENCRYPTED output %s\n", i, ret , TXT_VALID_LENGTH, output);
ritesh2094 0:20df98087dc9 68
ritesh2094 0:20df98087dc9 69 // We can use 64encoding to send data and to avoid encoding problems
ritesh2094 0:20df98087dc9 70 // In our case we use haxadecimal representation of the characters so no need.
ritesh2094 0:20df98087dc9 71 // mbedtls_base64_encode(encoded64, 200, &out_len, (const unsigned char *)output, strlen((const char*)output) );
ritesh2094 0:20df98087dc9 72 // printf("%d 64ENCODED ENCRYPTED output %s\n", i, encoded64);
ritesh2094 0:20df98087dc9 73
ritesh2094 0:20df98087dc9 74 pc.printf("%d HEX ENCRYPTED output\n", i);
ritesh2094 0:20df98087dc9 75 for(int j=0; j<TXT_VALID_LENGTH; j++)
ritesh2094 0:20df98087dc9 76 {
ritesh2094 0:20df98087dc9 77 pc.printf("%02x ", output[j]);
ritesh2094 0:20df98087dc9 78 }
ritesh2094 0:20df98087dc9 79 pc.printf("\n");
ritesh2094 0:20df98087dc9 80
ritesh2094 0:20df98087dc9 81 // We decrypt the OUTPUT1 and we get the same input string
ritesh2094 0:20df98087dc9 82
ritesh2094 0:20df98087dc9 83 mbedtls_aes_setkey_dec( &aes2, key, 256);
ritesh2094 0:20df98087dc9 84 ret = mbedtls_aes_crypt_cbc(&aes2, MBEDTLS_AES_DECRYPT, TXT_VALID_LENGTH, iv2, output, output2 );
ritesh2094 0:20df98087dc9 85 pc.printf("%d - Ret: %d - DECRYPTED output %s\n\n", i , ret, output2);
ritesh2094 0:20df98087dc9 86
ritesh2094 0:20df98087dc9 87 // Showing the decrypted result in HEX
ritesh2094 0:20df98087dc9 88 pc.printf("%d HEX DECRYPTED output\n", i, output2);
ritesh2094 0:20df98087dc9 89 for(int j=0; j<TXT_VALID_LENGTH; j++)
ritesh2094 0:20df98087dc9 90 {
ritesh2094 0:20df98087dc9 91 pc.printf("%02x ", output2[j]);
ritesh2094 0:20df98087dc9 92 }
ritesh2094 0:20df98087dc9 93 pc.printf("\n\n\n");
ritesh2094 0:20df98087dc9 94
ritesh2094 0:20df98087dc9 95 i++;
ritesh2094 0:20df98087dc9 96 // Wait 2 seconds and re-do it.
ritesh2094 0:20df98087dc9 97 wait(2);
ritesh2094 0:20df98087dc9 98 }
ritesh2094 0:20df98087dc9 99
ritesh2094 0:20df98087dc9 100 }
ritesh2094 0:20df98087dc9 101
ritesh2094 0:20df98087dc9 102 void init_ivs(unsigned char iv_orig[], unsigned char iv1[], unsigned char iv2[])
ritesh2094 0:20df98087dc9 103 {
ritesh2094 0:20df98087dc9 104 for(int i=0; i<IV_SIZE; i++){
ritesh2094 0:20df98087dc9 105
ritesh2094 0:20df98087dc9 106 iv2[i] = iv1[i] = iv_orig[i];
ritesh2094 0:20df98087dc9 107
ritesh2094 0:20df98087dc9 108 }
ritesh2094 0:20df98087dc9 109 }