Arduino Cryptography Library
ChaCha.h
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22 
23 #ifndef CRYPTO_CHACHA_h
24 #define CRYPTO_CHACHA_h
25 
26 #include "Cipher.h"
27 
28 class ChaChaPoly;
29 
30 class ChaCha : public Cipher
31 {
32 public:
33  explicit ChaCha(uint8_t numRounds = 20);
34  virtual ~ChaCha();
35 
36  size_t keySize() const;
37  size_t ivSize() const;
38 
39  uint8_t numRounds() const { return rounds; }
40  void setNumRounds(uint8_t numRounds) { rounds = numRounds; }
41 
42  bool setKey(const uint8_t *key, size_t len);
43  bool setIV(const uint8_t *iv, size_t len);
44  bool setCounter(const uint8_t *counter, size_t len);
45 
46  void encrypt(uint8_t *output, const uint8_t *input, size_t len);
47  void decrypt(uint8_t *output, const uint8_t *input, size_t len);
48 
49  void clear();
50 
51  static void hashCore(uint32_t *output, const uint32_t *input, uint8_t rounds);
52 
53 private:
54  uint8_t block[64];
55  uint8_t stream[64];
56  uint8_t rounds;
57  uint8_t posn;
58 
59  void keystreamBlock(uint32_t *output);
60 
61  friend class ChaChaPoly;
62 };
63 
64 #endif
Authenticated cipher based on ChaCha and Poly1305.
Definition: ChaChaPoly.h:31
ChaCha stream cipher.
Definition: ChaCha.h:31
void setNumRounds(uint8_t numRounds)
Sets the number of encryption rounds.
Definition: ChaCha.h:40
void decrypt(uint8_t *output, const uint8_t *input, size_t len)
Decrypts an input buffer and writes the plaintext to an output buffer.
Definition: ChaCha.cpp:190
static void hashCore(uint32_t *output, const uint32_t *input, uint8_t rounds)
Executes the ChaCha hash core on an input memory block.
Definition: ChaCha.cpp:253
uint8_t numRounds() const
Returns the number of encryption rounds; usually 8, 12, or 20.
Definition: ChaCha.h:39
ChaCha(uint8_t numRounds=20)
Constructs a new ChaCha stream cipher.
Definition: ChaCha.cpp:47
bool setKey(const uint8_t *key, size_t len)
Sets the key to use for future encryption and decryption operations.
Definition: ChaCha.cpp:87
bool setIV(const uint8_t *iv, size_t len)
Sets the initialization vector to use for future encryption and decryption operations.
Definition: ChaCha.cpp:111
size_t keySize() const
Default size of the key for this cipher, in bytes.
Definition: ChaCha.cpp:59
size_t ivSize() const
Size of the initialization vector for this cipher, in bytes.
Definition: ChaCha.cpp:65
bool setCounter(const uint8_t *counter, size_t len)
Sets the starting counter for encryption.
Definition: ChaCha.cpp:145
void encrypt(uint8_t *output, const uint8_t *input, size_t len)
Encrypts an input buffer and writes the ciphertext to an output buffer.
Definition: ChaCha.cpp:158
void clear()
Clears all security-sensitive state from this cipher.
Definition: ChaCha.cpp:218
Abstract base class for stream ciphers.
Definition: Cipher.h:30