Botan  2.4.0
Crypto and TLS for C++11
Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
Botan::ChaCha20Poly1305_Mode Class Referenceabstract

#include <chacha20poly1305.h>

Inheritance diagram for Botan::ChaCha20Poly1305_Mode:
Botan::AEAD_Mode Botan::Cipher_Mode Botan::ChaCha20Poly1305_Decryption Botan::ChaCha20Poly1305_Encryption

Public Member Functions

bool authenticated () const override
 
void clear () override
 
size_t default_nonce_length () const override
 
virtual void finish (secure_vector< uint8_t > &final_block, size_t offset=0)=0
 
Key_Length_Specification key_spec () const override
 
virtual size_t minimum_final_size () const =0
 
std::string name () const override
 
virtual size_t output_length (size_t input_length) const =0
 
virtual size_t process (uint8_t msg[], size_t msg_len)=0
 
virtual std::string provider () const
 
void reset () override
 
template<typename Alloc >
void set_ad (const std::vector< uint8_t, Alloc > &ad)
 
void set_associated_data (const uint8_t ad[], size_t ad_len) override
 
template<typename Alloc >
void set_associated_data_vec (const std::vector< uint8_t, Alloc > &ad)
 
template<typename Alloc >
void set_key (const std::vector< uint8_t, Alloc > &key)
 
void set_key (const SymmetricKey &key)
 
void set_key (const uint8_t key[], size_t length)
 
template<typename Alloc >
void start (const std::vector< uint8_t, Alloc > &nonce)
 
void start (const uint8_t nonce[], size_t nonce_len)
 
void start ()
 
size_t tag_size () const override
 
void update (secure_vector< uint8_t > &buffer, size_t offset=0)
 
size_t update_granularity () const override
 
bool valid_keylength (size_t length) const
 
bool valid_nonce_length (size_t n) const override
 

Static Public Member Functions

static std::vector< std::string > providers (const std::string &algo_spec)
 

Protected Member Functions

bool cfrg_version () const
 
 ChaCha20Poly1305_Mode ()
 
void update_len (size_t len)
 

Protected Attributes

secure_vector< uint8_t > m_ad
 
std::unique_ptr< StreamCipherm_chacha
 
size_t m_ctext_len = 0
 
size_t m_nonce_len = 0
 
std::unique_ptr< MessageAuthenticationCodem_poly1305
 

Detailed Description

Base class See draft-irtf-cfrg-chacha20-poly1305-03 for specification If a nonce of 64 bits is used the older version described in draft-agl-tls-chacha20poly1305-04 is used instead.

Definition at line 24 of file chacha20poly1305.h.

Constructor & Destructor Documentation

◆ ChaCha20Poly1305_Mode()

Botan::ChaCha20Poly1305_Mode::ChaCha20Poly1305_Mode ( )
protected

Definition at line 13 of file chacha20poly1305.cpp.

References m_chacha, and m_poly1305.

13  :
14  m_chacha(StreamCipher::create("ChaCha")),
16  {
17  if(!m_chacha || !m_poly1305)
18  throw Algorithm_Not_Found("ChaCha20Poly1305");
19  }
static std::unique_ptr< MessageAuthenticationCode > create(const std::string &algo_spec, const std::string &provider="")
Definition: mac.cpp:45
std::unique_ptr< MessageAuthenticationCode > m_poly1305
std::unique_ptr< StreamCipher > m_chacha
static std::unique_ptr< StreamCipher > create(const std::string &algo_spec, const std::string &provider="")

Member Function Documentation

◆ authenticated()

bool Botan::AEAD_Mode::authenticated ( ) const
inlineoverridevirtualinherited
Returns
true iff this mode provides authentication as well as confidentiality.

Reimplemented from Botan::Cipher_Mode.

Definition at line 25 of file aead.h.

25 { return true; }

◆ cfrg_version()

bool Botan::ChaCha20Poly1305_Mode::cfrg_version ( ) const
inlineprotected

◆ clear()

void Botan::ChaCha20Poly1305_Mode::clear ( )
overridevirtual

Zeroise all state See also reset_msg()

Implements Botan::Cipher_Mode.

Definition at line 26 of file chacha20poly1305.cpp.

References m_chacha, m_poly1305, and reset().

27  {
28  m_chacha->clear();
29  m_poly1305->clear();
30  reset();
31  }
std::unique_ptr< MessageAuthenticationCode > m_poly1305
std::unique_ptr< StreamCipher > m_chacha

◆ default_nonce_length()

size_t Botan::AEAD_Mode::default_nonce_length ( ) const
inlineoverridevirtualinherited
Returns
default AEAD nonce size (a commonly supported value among AEAD modes, and large enough that random collisions are unlikely)

Implements Botan::Cipher_Mode.

Reimplemented in Botan::TLS::TLS_CBC_HMAC_AEAD_Mode, and Botan::CCM_Mode.

Definition at line 75 of file aead.h.

References BOTAN_PUBLIC_API, and Botan::get_aead().

75 { return 12; }

◆ finish()

virtual void Botan::Cipher_Mode::finish ( secure_vector< uint8_t > &  final_block,
size_t  offset = 0 
)
pure virtualinherited

◆ key_spec()

Key_Length_Specification Botan::ChaCha20Poly1305_Mode::key_spec ( ) const
inlineoverridevirtual
Returns
object describing limits on key size

Implements Botan::Cipher_Mode.

Definition at line 33 of file chacha20poly1305.h.

34  { return Key_Length_Specification(32); }

◆ minimum_final_size()

virtual size_t Botan::Cipher_Mode::minimum_final_size ( ) const
pure virtualinherited

◆ name()

std::string Botan::ChaCha20Poly1305_Mode::name ( ) const
inlineoverridevirtual

Implements Botan::Cipher_Mode.

Definition at line 29 of file chacha20poly1305.h.

Referenced by update_len().

29 { return "ChaCha20Poly1305"; }

◆ output_length()

virtual size_t Botan::Cipher_Mode::output_length ( size_t  input_length) const
pure virtualinherited

◆ process()

virtual size_t Botan::Cipher_Mode::process ( uint8_t  msg[],
size_t  msg_len 
)
pure virtualinherited

Process message blocks

Input must be a multiple of update_granularity

Processes msg in place and returns bytes written. Normally this will be either msg_len (indicating the entire message was processed) or for certain AEAD modes zero (indicating that the mode requires the entire message be processed in one pass).

Parameters
msgthe message to be processed
msg_lenlength of the message in bytes

Implemented in Botan::OCB_Decryption, Botan::CBC_Decryption, Botan::EAX_Decryption, Botan::GCM_Decryption, Botan::OCB_Encryption, Botan::CFB_Decryption, Botan::ChaCha20Poly1305_Decryption, Botan::XTS_Decryption, Botan::EAX_Encryption, Botan::GCM_Encryption, Botan::CBC_Encryption, Botan::CFB_Encryption, Botan::ChaCha20Poly1305_Encryption, Botan::XTS_Encryption, Botan::TLS::TLS_CBC_HMAC_AEAD_Mode, Botan::SIV_Mode, Botan::CCM_Mode, and Botan::Stream_Cipher_Mode.

Referenced by Botan::TLS::check_tls_cbc_padding(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::set_associated_data().

◆ provider()

virtual std::string Botan::Cipher_Mode::provider ( ) const
inlinevirtualinherited
Returns
provider information about this implementation. Default is "base", might also return "sse2", "avx2", "openssl", or some other arbitrary string.

Reimplemented in Botan::GCM_Mode.

Definition at line 208 of file cipher_mode.h.

208 { return "base"; }

◆ providers()

std::vector< std::string > Botan::Cipher_Mode::providers ( const std::string &  algo_spec)
staticinherited
Returns
list of available providers for this algorithm, empty if not available
Parameters
algo_specalgorithm name

Definition at line 158 of file cipher_mode.cpp.

References Botan::ENCRYPTION, and Botan::get_cipher_mode().

159  {
160  const std::vector<std::string>& possible = { "base", "openssl" };
161  std::vector<std::string> providers;
162  for(auto&& prov : possible)
163  {
164  std::unique_ptr<Cipher_Mode> mode(get_cipher_mode(algo_spec, ENCRYPTION, prov));
165  if(mode)
166  {
167  providers.push_back(prov); // available
168  }
169  }
170  return providers;
171  }
Cipher_Mode * get_cipher_mode(const std::string &algo, Cipher_Dir direction, const std::string &provider)
Definition: cipher_mode.cpp:40
static std::vector< std::string > providers(const std::string &algo_spec)

◆ reset()

void Botan::ChaCha20Poly1305_Mode::reset ( )
overridevirtual

Resets just the message specific state and allows encrypting again under the existing key

Implements Botan::Cipher_Mode.

Definition at line 33 of file chacha20poly1305.cpp.

References m_ad, m_chacha, m_ctext_len, and m_nonce_len.

Referenced by clear().

34  {
35  m_ad.clear();
36  m_ctext_len = 0;
37  m_nonce_len = 0;
38  }
secure_vector< uint8_t > m_ad

◆ set_ad()

template<typename Alloc >
void Botan::AEAD_Mode::set_ad ( const std::vector< uint8_t, Alloc > &  ad)
inlineinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

See set_associated_data().

Parameters
adthe associated data

Definition at line 66 of file aead.h.

Referenced by Botan::TLS::write_record().

67  {
68  set_associated_data(ad.data(), ad.size());
69  }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0

◆ set_associated_data()

void Botan::ChaCha20Poly1305_Mode::set_associated_data ( const uint8_t  ad[],
size_t  ad_len 
)
overridevirtual

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

Unless reset by another call, the associated data is kept between messages. Thus, if the AD does not change, calling once (after set_key) is the optimum.

Parameters
adthe associated data
ad_lenlength of add in bytes

Implements Botan::AEAD_Mode.

Definition at line 45 of file chacha20poly1305.cpp.

References m_ad, and m_ctext_len.

46  {
47  if(m_ctext_len)
48  throw Exception("Too late to set AD for ChaCha20Poly1305");
49  m_ad.assign(ad, ad + length);
50  }
secure_vector< uint8_t > m_ad

◆ set_associated_data_vec()

template<typename Alloc >
void Botan::AEAD_Mode::set_associated_data_vec ( const std::vector< uint8_t, Alloc > &  ad)
inlineinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

See set_associated_data().

Parameters
adthe associated data

Definition at line 51 of file aead.h.

Referenced by Botan::TLS::write_record().

52  {
53  set_associated_data(ad.data(), ad.size());
54  }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0

◆ set_key() [1/3]

template<typename Alloc >
void Botan::Cipher_Mode::set_key ( const std::vector< uint8_t, Alloc > &  key)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material

Definition at line 178 of file cipher_mode.h.

Referenced by botan_cipher_set_key(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec().

179  {
180  set_key(key.data(), key.size());
181  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:178

◆ set_key() [2/3]

void Botan::Cipher_Mode::set_key ( const SymmetricKey key)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material

Definition at line 187 of file cipher_mode.h.

References Botan::OctetString::begin(), and Botan::OctetString::length().

188  {
189  set_key(key.begin(), key.length());
190  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:178

◆ set_key() [3/3]

void Botan::Cipher_Mode::set_key ( const uint8_t  key[],
size_t  length 
)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material
lengthin bytes of key param

Definition at line 197 of file cipher_mode.h.

198  {
199  if(!valid_keylength(length))
200  throw Invalid_Key_Length(name(), length);
201  key_schedule(key, length);
202  }
virtual std::string name() const =0
bool valid_keylength(size_t length) const
Definition: cipher_mode.h:168

◆ start() [1/3]

template<typename Alloc >
void Botan::Cipher_Mode::start ( const std::vector< uint8_t, Alloc > &  nonce)
inlineinherited

Begin processing a message.

Parameters
noncethe per message nonce

Definition at line 44 of file cipher_mode.h.

Referenced by botan_cipher_start(), Botan::TLS::check_tls_cbc_padding(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::set_associated_data(), and Botan::TLS::write_record().

45  {
46  start_msg(nonce.data(), nonce.size());
47  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ start() [2/3]

void Botan::Cipher_Mode::start ( const uint8_t  nonce[],
size_t  nonce_len 
)
inlineinherited

Begin processing a message.

Parameters
noncethe per message nonce
nonce_lenlength of nonce

Definition at line 54 of file cipher_mode.h.

55  {
56  start_msg(nonce, nonce_len);
57  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ start() [3/3]

void Botan::Cipher_Mode::start ( )
inlineinherited

Begin processing a message.

Definition at line 62 of file cipher_mode.h.

63  {
64  return start_msg(nullptr, 0);
65  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ tag_size()

size_t Botan::ChaCha20Poly1305_Mode::tag_size ( ) const
inlineoverridevirtual
Returns
the size of the authentication tag used (in bytes)

Reimplemented from Botan::Cipher_Mode.

Definition at line 38 of file chacha20poly1305.h.

Referenced by Botan::ChaCha20Poly1305_Encryption::finish(), and Botan::ChaCha20Poly1305_Decryption::finish().

38 { return 16; }

◆ update()

void Botan::Cipher_Mode::update ( secure_vector< uint8_t > &  buffer,
size_t  offset = 0 
)
inlineinherited

Process some data. Input must be in size update_granularity() uint8_t blocks.

Parameters
bufferin/out parameter which will possibly be resized
offsetan offset into blocks to begin processing

Definition at line 87 of file cipher_mode.h.

References BOTAN_ASSERT.

Referenced by botan_cipher_update(), Botan::XTS_Encryption::finish(), Botan::ChaCha20Poly1305_Encryption::finish(), Botan::CFB_Encryption::finish(), Botan::CBC_Encryption::finish(), Botan::EAX_Encryption::finish(), Botan::XTS_Decryption::finish(), Botan::CFB_Decryption::finish(), Botan::CTS_Encryption::finish(), Botan::CBC_Decryption::finish(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), Botan::CTS_Decryption::finish(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::finish().

88  {
89  BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
90  uint8_t* buf = buffer.data() + offset;
91  const size_t buf_size = buffer.size() - offset;
92 
93  const size_t written = process(buf, buf_size);
94  buffer.resize(offset + written);
95  }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:29
virtual size_t process(uint8_t msg[], size_t msg_len)=0

◆ update_granularity()

size_t Botan::ChaCha20Poly1305_Mode::update_granularity ( ) const
inlineoverridevirtual
Returns
size of required blocks to update

Implements Botan::Cipher_Mode.

Definition at line 31 of file chacha20poly1305.h.

31 { return 64; }

◆ update_len()

void Botan::ChaCha20Poly1305_Mode::update_len ( size_t  len)
protected

Definition at line 52 of file chacha20poly1305.cpp.

References cfrg_version(), m_ad, m_chacha, m_ctext_len, m_nonce_len, m_poly1305, name(), Botan::store_le(), and valid_nonce_length().

Referenced by Botan::ChaCha20Poly1305_Encryption::finish(), and Botan::ChaCha20Poly1305_Decryption::finish().

53  {
54  uint8_t len8[8] = { 0 };
55  store_le(static_cast<uint64_t>(len), len8);
56  m_poly1305->update(len8, 8);
57  }
std::unique_ptr< MessageAuthenticationCode > m_poly1305
void store_le(uint16_t in, uint8_t out[2])
Definition: loadstor.h:450

◆ valid_keylength()

bool Botan::Cipher_Mode::valid_keylength ( size_t  length) const
inlineinherited

Check whether a given key length is valid for this algorithm.

Parameters
lengththe key length to be checked.
Returns
true if the key length is valid.

Definition at line 168 of file cipher_mode.h.

169  {
170  return key_spec().valid_keylength(length);
171  }
virtual Key_Length_Specification key_spec() const =0
bool valid_keylength(size_t length) const
Definition: key_spec.h:51

◆ valid_nonce_length()

bool Botan::ChaCha20Poly1305_Mode::valid_nonce_length ( size_t  nonce_len) const
overridevirtual
Returns
true iff nonce_len is a valid length for the nonce

Implements Botan::Cipher_Mode.

Definition at line 21 of file chacha20poly1305.cpp.

Referenced by update_len().

22  {
23  return (n == 8 || n == 12);
24  }

Member Data Documentation

◆ m_ad

secure_vector<uint8_t> Botan::ChaCha20Poly1305_Mode::m_ad
protected

◆ m_chacha

std::unique_ptr<StreamCipher> Botan::ChaCha20Poly1305_Mode::m_chacha
protected

◆ m_ctext_len

size_t Botan::ChaCha20Poly1305_Mode::m_ctext_len = 0
protected

◆ m_nonce_len

size_t Botan::ChaCha20Poly1305_Mode::m_nonce_len = 0
protected

Definition at line 51 of file chacha20poly1305.h.

Referenced by reset(), and update_len().

◆ m_poly1305

std::unique_ptr<MessageAuthenticationCode> Botan::ChaCha20Poly1305_Mode::m_poly1305
protected

The documentation for this class was generated from the following files: