Encryption Difference between processor and coprocessor - c

Question

i am trying to handle a problem using encryption and decryption algorithms, i used below program to test my requirements and i realised an odd problem.
i am using polarssl for my encryption and decryption needs.
This program works well when i compile it with icc compiler on intel processor using this command :(aes.c from polarssl)
icc Deneme.c aes.c -o deneme
Output:
Encryption result, encrypted value:
11 22 7 86 a2 d3 ed 95 b9 14 c0 57 f7 af 5f dc 93 66 77 68 44 12 9f 1b 72 6a ea 51 b8 f7 1d a4
Decryption result, plain array:
a2 d8 69 9c 77 73 c7 5e 1d 3b 83 26 6e 2f 35 30 9d f0 f2 e5 0 0 0 0 0 0 0 0 0 0 0 0
When i tried to compile with icc compiler but this time run on microprocessor; encryption result are not true.
command:
icc -mmic Deneme.c aes.c -o deneme
Output:
Encryption result, encrypted value:
4a 4b 4c 32 e0 ef fb 22 4a 67 7e 2c 3a fe 36 65 4b 5b 18 9 63 28 a1 c4 8e b7 e4 c6 33 a7 36 7c
Decryption result, plain array:
a2 d8 69 9c 77 73 c7 5e 1d 3b 83 26 6e 2f 35 30 9d f0 f2 e5 0 0 0 0 0 0 0 0 0 0 0 0
What makes my encrypted values different??
here is full program
#include <stdio.h>
#include <polarssl/aes.h>
const int ENCRIPTION = 1;
const int DECRIPTION = 0;
void printByteArray(unsigned char * array, int length) {
int i = 0;
for (i = 0; i < length; i++) {
printf("%x ", array[i]);
}
printf("\n");
}
void encrypt() {
unsigned char o[32];
unsigned char key[16] = { 0x03, 0xC9, 0xD8, 0xE6, 0x01, 0xA5, 0x05,
0x9F, 0x11, 0xBF, 0x44, 0x9D, 0xF9, 0x55, 0x18, 0xED
};
unsigned char iv[16] = { 0x03, 0xB5, 0x62, 0x57, 0xC8, 0x69, 0x22, 0x89,
0xF4, 0x96, 0x2B, 0x05, 0x44, 0x2B, 0xD0, 0xA7
};
unsigned char plain[32]=
{
0xA2, 0xD8, 0x69, 0x9C, 0x77, 0x73, 0xC7, 0x5E, 0x1D, 0x3B, 0x83, 0x26, 0x6E, 0x2F, 0x35, 0x30,
0x9D, 0xF0, 0xF2, 0xE5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
aes_context aesCtx;
aes_setkey_enc(&aesCtx, key, 128);
aes_crypt_cbc(&aesCtx, ENCRIPTION, 32, iv, plain, o);
printf("Encryption result, encrypted value:\n");
printByteArray(o, 32);
}
decrypt() {
unsigned char o[32];
unsigned char key[16] = { 0x03, 0xC9, 0xD8, 0xE6, 0x01, 0xA5, 0x05,
0x9F, 0x11, 0xBF, 0x44, 0x9D, 0xF9, 0x55, 0x18, 0xED
};
unsigned char iv[16] = { 0x03, 0xB5, 0x62, 0x57, 0xC8, 0x69, 0x22, 0x89,
0xF4, 0x96, 0x2B, 0x05, 0x44, 0x2B, 0xD0, 0xA7
};
unsigned char encryptedValue[32] = { 0x11, 0x22, 0x07, 0x86,
0xA2, 0xD3, 0xED, 0x95, 0xB9, 0x14, 0xC0, 0x57, 0xF7, 0xAF, 0x5F,
0xDC, 0x93, 0x66, 0x77, 0x68, 0x44, 0x12, 0x9F, 0x1B, 0x72, 0x6A,
0xEA, 0x51, 0xB8, 0xF7, 0x1D, 0xA4 };
aes_context aesCtx;
aes_setkey_dec(&aesCtx, key, 128);
aes_crypt_cbc(&aesCtx, DECRIPTION, 32, iv, encryptedValue,
o);
printf("Decryption result, plain array:\n");
printByteArray(o, 32);
}
int main() {
encrypt();
decrypt();
}

Answer 1

icc by default uses optimization for performance on your code and this limits correctness. However, you can use -O0 option to compile without any optimization on both and compare the results.
-mmic generates instruction set for MIC ie Xeon phi architecture.