Complete AES 128 encryption

Author: lmshao

AES.c

@@ -0,0 +1,258 @@
+//
+// Created by Liming Shao on 2018/4/24.
+//
+
+#include "AES.h"
+#include <stdio.h>
+#include <string.h>
+
+#define BLOCKSIZE 16
+
+#define LOAD32H(x, y) \
+  do { (x) = ((uint32_t)((y)[0] & 0xff)<<24) | ((uint32_t)((y)[1] & 0xff)<<16) | \
+             ((uint32_t)((y)[2] & 0xff)<<8)  | ((uint32_t)((y)[3] & 0xff));} while(0)
+
+#define STORE32H(x, y) \
+  do { (y)[0] = (uint8_t)(((x)>>24) & 0xff); (y)[1] = (uint8_t)(((x)>>16) & 0xff);   \
+       (y)[2] = (uint8_t)(((x)>>8) & 0xff); (y)[3] = (uint8_t)((x) & 0xff); } while(0)
+
+/* extract a byte */
+#define BYTE(x, n) (((x) >> (8 * (n))) & 0xff)
+
+/* used for keyExpansion */
+#define MIX(x) (((S[BYTE(x, 2)] << 24) & 0xff000000) ^ ((S[BYTE(x, 1)] << 16) & 0xff0000) ^ \
+                ((S[BYTE(x, 0)] << 8) & 0xff00) ^ (S[BYTE(x, 3)] & 0xff))
+
+#define ROF32(x, n)  (((x) << (n)) | ((x) >> (32-(n))))
+
+/* for 128-bit blocks, Rijndael never uses more than 10 rcon values */
+static const uint32_t rcon[10] = {
+        0x01000000UL, 0x02000000UL, 0x04000000UL, 0x08000000UL, 0x10000000UL,
+        0x20000000UL, 0x40000000UL, 0x80000000UL, 0x1B000000UL, 0x36000000UL
+};
+
+unsigned char S[256] = {
+        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
+};
+
+unsigned char inv_S[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
+};
+
+/* copy in[16] to state[4][4] */
+int loadStateArray(uint8_t (*state)[4], const uint8_t *in) {
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j) {
+            state[j][i] = *in++;
+        }
+    }
+    return 0;
+}
+
+/* copy state[4][4] to out[16] */
+int storeStateArray(uint8_t (*state)[4], uint8_t *out) {
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j) {
+            *out++ = state[j][i];
+        }
+    }
+    return 0;
+}
+
+int keyExpansion(const uint8_t *key, uint32_t keyLen, AesKey *aesKey) {
+
+    if (NULL == key || NULL == aesKey){
+        printf("keyExpansion param is NULL\n");
+        return -1;
+    }
+
+    if (keyLen != 16){
+        printf("keyExpansion keyLen = %d, Not support.\n", keyLen);
+        return -1;
+    }
+
+    uint32_t *w = aesKey->eK;
+
+    /* keyLen is 16 Bytes, generate uint32_t W[44]. */
+
+    /* W[0-3] */
+    for (int i = 0; i < 4; ++i) {
+        LOAD32H(w[i], key + 4*i);
+    }
+
+    /* W[4-43] */
+    for (int i = 0; i < 10; ++i) {
+        w[4] = w[0] ^ MIX(w[3]) ^ rcon[i];
+        w[5] = w[1] ^ w[4];
+        w[6] = w[2] ^ w[5];
+        w[7] = w[3] ^ w[6];
+        w += 4;
+    }
+
+    return 0;
+}
+
+int addRoundKey(uint8_t (*state)[4], const uint32_t *key) {
+    uint8_t k[4][4];
+
+    /* i: row, j: col */
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j) {
+            k[i][j] = (uint8_t) BYTE(key[j], 3 - i);  /* copy uint32 key[4] to uint8 k[4][4] */
+            state[i][j] ^= k[i][j];
+        }
+    }
+
+    return 0;
+}
+
+int subBytes(uint8_t (*state)[4]) {
+    /* i: row, j: col */
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j) {
+            state[i][j] = S[state[i][j]];
+        }
+    }
+
+    return 0;
+}
+
+int shiftRows(uint8_t (*state)[4]) {
+    uint32_t block[4] = {0};
+
+    /* i: row */
+    for (int i = 0; i < 4; ++i) {
+        LOAD32H(block[i], state[i]);
+        block[i] = ROF32(block[i], 8*i);
+        STORE32H(block[i], state[i]);
+    }
+
+    return 0;
+}
+
+/* Galois Field (256) Multiplication of two Bytes */
+uint8_t GMul(uint8_t u, uint8_t v) {
+    uint8_t p = 0;
+
+    for (int i = 0; i < 8; ++i) {
+        if (u & 0x01) {    //
+            p ^= v;
+        }
+
+        int flag = (v & 0x80);
+        v <<= 1;
+        if (flag) {
+            v ^= 0x1B; /* x^8 + x^4 + x^3 + x + 1 */
+        }
+
+        u >>= 1;
+    }
+
+    return p;
+}
+
+int mixColumns(uint8_t (*state)[4]) {
+    uint8_t tmp[4][4];
+    uint8_t M[4][4] = {{0x02, 0x03, 0x01, 0x01},
+                       {0x01, 0x02, 0x03, 0x01},
+                       {0x01, 0x01, 0x02, 0x03},
+                       {0x03, 0x01, 0x01, 0x02}};
+
+    /* copy state[4][4] to tmp[4][4] */
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j){
+            tmp[i][j] = state[i][j];
+        }
+    }
+
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j) {
+            state[i][j] = GMul(M[i][0], tmp[0][j]) ^ GMul(M[i][1], tmp[1][j])
+                        ^ GMul(M[i][2], tmp[2][j]) ^ GMul(M[i][3], tmp[3][j]);
+        }
+    }
+
+    return 0;
+}
+
+int aesEncrypt(const uint8_t *key, uint32_t keyLen, const uint8_t *pt, uint8_t *ct, uint32_t len) {
+
+    AesKey aesKey;
+    uint8_t *pos = ct;
+    const uint32_t *rk = aesKey.eK;
+    uint8_t out[BLOCKSIZE] = {0};
+    uint8_t actualKey[16] = {0};
+    uint8_t state[4][4] = {0};
+
+    if (NULL == key || NULL == pt || NULL == ct){
+        printf("param err.\n");
+        return -1;
+    }
+
+    if (keyLen > 16){
+        printf("keyLen must be 16.\n");
+        return -1;
+    }
+
+    if (len % BLOCKSIZE){
+        printf("inLen is invalid.\n");
+        return -1;
+    }
+
+    memcpy(actualKey, key, keyLen);
+    keyExpansion(actualKey, 16, &aesKey);
+
+    for (int i = 0; i < len; i += BLOCKSIZE) {
+
+        loadStateArray(state, pt);
+        addRoundKey(state, rk);
+
+        for (int j = 1; j < 10; ++j) {
+            rk += 4;
+            subBytes(state);
+            shiftRows(state);
+            mixColumns(state);
+            addRoundKey(state, rk);
+        }
+
+        subBytes(state);
+        shiftRows(state);
+        addRoundKey(state, rk+4);
+
+        storeStateArray(state, pos);
+
+        pos += BLOCKSIZE;
+        pt += BLOCKSIZE;
+    }
+    return 0;
+}

AES.h

@@ -0,0 +1,42 @@
+//
+// Created by Liming Shao on 2018/4/24.
+//
+
+#ifndef AES_AES_H
+#define AES_AES_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+typedef struct{
+    uint32_t eK[44], dK[60];    // encKey, decKey
+    int Nr; // 10 rounds
+}AesKey;
+
+int loadStateArray(uint8_t state[4][4], const uint8_t *in);
+
+int storeStateArray(uint8_t state[4][4], uint8_t *out);
+
+int keyExpansion(const uint8_t *key, uint32_t keyLen, AesKey *aesKey);
+
+int addRoundKey(uint8_t state[4][4], const uint32_t key[4]);
+
+int subBytes(uint8_t state[4][4]);
+
+int shiftRows(uint8_t state[4][4]);
+
+uint8_t GMul(uint8_t a, uint8_t b);
+
+int mixColumns(uint8_t state[4][4]);
+
+// data length must be multiple of 16B, so data need to be padded before encryption/decryption
+int aesEncrypt(const uint8_t *key, uint32_t keyLen, const uint8_t *pt, uint8_t *ct, uint32_t len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif //AES_AES_H

CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.8.2)
+project(AES)
+
+set(CMAKE_C_STANDARD 99)
+
+set(SOURCE_FILES main.c AES.h AES.c Utils.c Utils.h)
+add_executable(AES ${SOURCE_FILES})

Utils.c

@@ -0,0 +1,22 @@
+//
+// Created by Liming Shao on 4/30/2018.
+//
+
+#include <stdio.h>
+#include "Utils.h"
+
+void printHex(uint8_t *ptr, int len, char *tag) {
+    printf("%s\ndata[%d]: ", tag, len);
+    for (int i = 0; i < len; ++i) {
+        printf("%0.2X ", *ptr++);
+    }
+    printf("\n");
+}
+
+void printState(uint8_t (*state)[4], char *tag) {
+    printf("%s\n", tag);
+    for (int i = 0; i < 4; ++i) {
+        printf("%0.2X %0.2X %0.2X %0.2X\n", state[i][0], state[i][1], state[i][2], state[i][3]);
+    }
+    printf("\n");
+}

Utils.h

@@ -0,0 +1,14 @@
+//
+// Created by Liming Shao on 4/30/2018.
+//
+
+#ifndef AES_UTILS_H
+#define AES_UTILS_H
+
+#include <stdint.h>
+
+void printHex(uint8_t *ptr, int len, char *tag);
+
+void printState(uint8_t state[4][4], char *tag);
+
+#endif //AES_UTILS_H

main.c

@@ -0,0 +1,25 @@
+//
+// Created by Liming Shao on 2018/4/24.
+//
+
+#include <stdio.h>
+#include "AES.h"
+#include "Utils.h"
+
+int main() {
+
+    const uint8_t key[16] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
+    const uint8_t pt[16]={0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x31, 0x31, 0x98, 0xa2, 0xe0, 0x37, 0x07, 0x34};
+    uint8_t ct[16] = {0};
+    aesEncrypt(key, 16, pt, ct, 16);
+    printf("expect: 39 25 84 1D 02 DC 09 FB DC 11 85 97 19 6A 0B 32\n");
+    printHex(ct, 16, "cipher data:");
+
+    const uint8_t key1[]="1234567890123456";
+    const uint8_t *data = (uint8_t*)"abcdefghijklmnop";
+    aesEncrypt(key1, 16, data, ct, 16);
+    printf("\nexpect: fcad715bd73b5cb0488f840f3bad7889\n");
+    printHex(ct, 16, "cipher data:");
+
+    return 0;
+}