Embedded systems coursework 2.
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cipher/BlockCipher.cpp@16:c702a2fd256e, 2018-03-23 (annotated)
- Committer:
- trod
- Date:
- Fri Mar 23 20:04:35 2018 +0000
- Revision:
- 16:c702a2fd256e
- Parent:
- 14:f04410cef037
final
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
feb11 | 8:a090264e9b2d | 1 | #include "BlockCipher.h" |
feb11 | 8:a090264e9b2d | 2 | #include <string.h> |
feb11 | 8:a090264e9b2d | 3 | |
feb11 | 8:a090264e9b2d | 4 | BlockCipher::BlockCipher(uint32_t bs, BLOCK_CIPHER_MODE m, uint8_t *iv): |
feb11 | 8:a090264e9b2d | 5 | Cipher(), |
feb11 | 8:a090264e9b2d | 6 | blockSize(bs), |
feb11 | 8:a090264e9b2d | 7 | mode(m), |
feb11 | 8:a090264e9b2d | 8 | IV(0) |
feb11 | 8:a090264e9b2d | 9 | { |
feb11 | 8:a090264e9b2d | 10 | if(mode == CBC_MODE) |
feb11 | 8:a090264e9b2d | 11 | { |
feb11 | 8:a090264e9b2d | 12 | IV = new uint8_t[blockSize]; |
feb11 | 8:a090264e9b2d | 13 | memcpy(IV, iv, blockSize); |
feb11 | 8:a090264e9b2d | 14 | } |
feb11 | 8:a090264e9b2d | 15 | } |
feb11 | 8:a090264e9b2d | 16 | |
feb11 | 8:a090264e9b2d | 17 | BlockCipher::~BlockCipher() |
feb11 | 8:a090264e9b2d | 18 | { |
feb11 | 8:a090264e9b2d | 19 | if(IV != 0) |
feb11 | 8:a090264e9b2d | 20 | delete[] IV; |
feb11 | 8:a090264e9b2d | 21 | } |
feb11 | 8:a090264e9b2d | 22 | |
feb11 | 8:a090264e9b2d | 23 | CIPHER_TYPE BlockCipher::getType() const |
feb11 | 8:a090264e9b2d | 24 | { |
feb11 | 8:a090264e9b2d | 25 | return BLOCK_CIPHER; |
feb11 | 8:a090264e9b2d | 26 | } |
feb11 | 8:a090264e9b2d | 27 | |
feb11 | 8:a090264e9b2d | 28 | uint32_t BlockCipher::getBlockSize() const |
feb11 | 8:a090264e9b2d | 29 | { |
feb11 | 8:a090264e9b2d | 30 | return blockSize; |
feb11 | 8:a090264e9b2d | 31 | } |
feb11 | 8:a090264e9b2d | 32 | |
feb11 | 8:a090264e9b2d | 33 | void BlockCipher::encrypt(uint8_t *out, uint8_t *in, uint32_t length) |
feb11 | 8:a090264e9b2d | 34 | { |
feb11 | 14:f04410cef037 | 35 | uint8_t *tmp = 0; |
feb11 | 14:f04410cef037 | 36 | if(mode == CBC_MODE) |
feb11 | 14:f04410cef037 | 37 | tmp = new uint8_t[getBlockSize()]; |
feb11 | 8:a090264e9b2d | 38 | for(uint32_t i = 0; i < length; i += getBlockSize()) |
feb11 | 8:a090264e9b2d | 39 | { |
feb11 | 14:f04410cef037 | 40 | if(mode == CBC_MODE) |
feb11 | 14:f04410cef037 | 41 | { |
feb11 | 14:f04410cef037 | 42 | memcpy(tmp, &in[i], getBlockSize()); |
feb11 | 14:f04410cef037 | 43 | for(int j = 0; j < (int)getBlockSize(); ++j) |
feb11 | 14:f04410cef037 | 44 | tmp[j] ^= IV[j]; |
feb11 | 14:f04410cef037 | 45 | |
feb11 | 14:f04410cef037 | 46 | encryptBlock(&out[i], tmp); |
feb11 | 8:a090264e9b2d | 47 | |
feb11 | 14:f04410cef037 | 48 | memcpy(IV, &out[i], getBlockSize()); |
feb11 | 14:f04410cef037 | 49 | } |
feb11 | 14:f04410cef037 | 50 | else |
feb11 | 14:f04410cef037 | 51 | encryptBlock(&out[i], &in[i]); |
feb11 | 8:a090264e9b2d | 52 | } |
feb11 | 14:f04410cef037 | 53 | if(mode == CBC_MODE) |
feb11 | 14:f04410cef037 | 54 | delete[] tmp; |
feb11 | 8:a090264e9b2d | 55 | } |
feb11 | 8:a090264e9b2d | 56 | |
feb11 | 8:a090264e9b2d | 57 | void BlockCipher::decrypt(uint8_t *out, uint8_t *in, uint32_t length) |
feb11 | 8:a090264e9b2d | 58 | { |
feb11 | 8:a090264e9b2d | 59 | for(uint32_t i = 0; i < length; i += getBlockSize()) |
feb11 | 8:a090264e9b2d | 60 | { |
feb11 | 14:f04410cef037 | 61 | if(mode == CBC_MODE) |
feb11 | 14:f04410cef037 | 62 | { |
feb11 | 14:f04410cef037 | 63 | decryptBlock(&out[i], &in[i]); |
feb11 | 14:f04410cef037 | 64 | for(int j = 0; j < (int)getBlockSize(); ++j) |
feb11 | 14:f04410cef037 | 65 | out[i+j] ^= IV[j]; |
feb11 | 8:a090264e9b2d | 66 | |
feb11 | 14:f04410cef037 | 67 | memcpy(IV, &in[i], getBlockSize()); |
feb11 | 14:f04410cef037 | 68 | } |
feb11 | 14:f04410cef037 | 69 | else |
feb11 | 14:f04410cef037 | 70 | decryptBlock(&out[i], &in[i]); |
feb11 | 8:a090264e9b2d | 71 | } |
feb11 | 8:a090264e9b2d | 72 | } |