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

#include <ctr.h>

Inheritance diagram for Botan::CTR_BE:
Botan::StreamCipher Botan::SymmetricAlgorithm

Public Member Functions

void cipher (const uint8_t in[], uint8_t out[], size_t length) override
 
void cipher1 (uint8_t buf[], size_t len)
 
void clear () override
 
CTR_BEclone () const override
 
 CTR_BE (BlockCipher *cipher)
 
 CTR_BE (BlockCipher *cipher, size_t ctr_size)
 
template<typename Alloc >
void decrypt (std::vector< uint8_t, Alloc > &inout)
 
template<typename Alloc >
void encipher (std::vector< uint8_t, Alloc > &inout)
 
template<typename Alloc >
void encrypt (std::vector< uint8_t, Alloc > &inout)
 
Key_Length_Specification key_spec () const override
 
size_t maximum_keylength () const
 
size_t minimum_keylength () const
 
std::string name () const override
 
virtual std::string provider () const
 
void seek (uint64_t offset) override
 
void set_iv (const uint8_t iv[], size_t iv_len) override
 
void set_key (const SymmetricKey &key)
 
template<typename Alloc >
void set_key (const std::vector< uint8_t, Alloc > &key)
 
void set_key (const uint8_t key[], size_t length)
 
bool valid_iv_length (size_t iv_len) const override
 
bool valid_keylength (size_t length) const
 

Static Public Member Functions

static std::unique_ptr< StreamCiphercreate (const std::string &algo_spec, const std::string &provider="")
 
static std::unique_ptr< StreamCiphercreate_or_throw (const std::string &algo_spec, const std::string &provider="")
 
static std::vector< std::string > providers (const std::string &algo_spec)
 

Protected Member Functions

void verify_key_set (bool cond) const
 

Detailed Description

CTR-BE (Counter mode, big-endian)

Definition at line 19 of file ctr.h.

Constructor & Destructor Documentation

◆ CTR_BE() [1/2]

Botan::CTR_BE::CTR_BE ( BlockCipher cipher)
explicit
Parameters
cipherthe block cipher to use

Definition at line 13 of file ctr.cpp.

13  :
14  m_cipher(ciph),
15  m_block_size(m_cipher->block_size()),
16  m_ctr_size(m_block_size),
17  m_ctr_blocks(m_cipher->parallel_bytes() / m_block_size),
18  m_counter(m_cipher->parallel_bytes()),
19  m_pad(m_counter.size()),
20  m_pad_pos(0)
21  {
22  }

◆ CTR_BE() [2/2]

Botan::CTR_BE::CTR_BE ( BlockCipher cipher,
size_t  ctr_size 
)

Definition at line 24 of file ctr.cpp.

24  :
25  m_cipher(cipher),
26  m_block_size(m_cipher->block_size()),
27  m_ctr_size(ctr_size),
28  m_ctr_blocks(m_cipher->parallel_bytes() / m_block_size),
29  m_counter(m_cipher->parallel_bytes()),
30  m_pad(m_counter.size()),
31  m_pad_pos(0)
32  {
33  if(m_ctr_size < 4 || m_ctr_size > m_block_size)
34  throw Invalid_Argument("Invalid CTR-BE counter size");
35  }
void cipher(const uint8_t in[], uint8_t out[], size_t length) override
Definition: ctr.cpp:63

Member Function Documentation

◆ cipher()

void Botan::CTR_BE::cipher ( const uint8_t  in[],
uint8_t  out[],
size_t  len 
)
overridevirtual

Encrypt or decrypt a message

Parameters
inthe plaintext
outthe byte array to hold the output, i.e. the ciphertext
lenthe length of both in and out in bytes

Implements Botan::StreamCipher.

Definition at line 63 of file ctr.cpp.

References Botan::SymmetricAlgorithm::verify_key_set(), and Botan::xor_buf().

64  {
65  verify_key_set(m_iv.empty() == false);
66 
67  const uint8_t* pad_bits = &m_pad[0];
68  const size_t pad_size = m_pad.size();
69 
70  if(m_pad_pos > 0)
71  {
72  const size_t avail = pad_size - m_pad_pos;
73  const size_t take = std::min(length, avail);
74  xor_buf(out, in, pad_bits + m_pad_pos, take);
75  length -= take;
76  in += take;
77  out += take;
78  m_pad_pos += take;
79 
80  if(take == avail)
81  {
82  add_counter(m_ctr_blocks);
83  m_cipher->encrypt_n(m_counter.data(), m_pad.data(), m_ctr_blocks);
84  m_pad_pos = 0;
85  }
86  }
87 
88  while(length >= pad_size)
89  {
90  xor_buf(out, in, pad_bits, pad_size);
91  length -= pad_size;
92  in += pad_size;
93  out += pad_size;
94 
95  add_counter(m_ctr_blocks);
96  m_cipher->encrypt_n(m_counter.data(), m_pad.data(), m_ctr_blocks);
97  }
98 
99  xor_buf(out, in, pad_bits, length);
100  m_pad_pos += length;
101  }
void verify_key_set(bool cond) const
Definition: sym_algo.h:95
void xor_buf(uint8_t out[], const uint8_t in[], size_t length)
Definition: mem_ops.h:163

◆ cipher1()

void Botan::StreamCipher::cipher1 ( uint8_t  buf[],
size_t  len 
)
inlineinherited

Encrypt or decrypt a message The message is encrypted/decrypted in place.

Parameters
bufthe plaintext / ciphertext
lenthe length of buf in bytes

Definition at line 66 of file stream_cipher.h.

Referenced by Botan::SIV_Encryption::finish().

67  { cipher(buf, buf, len); }
virtual void cipher(const uint8_t in[], uint8_t out[], size_t len)=0

◆ clear()

void Botan::CTR_BE::clear ( )
overridevirtual

Reset the state.

Implements Botan::SymmetricAlgorithm.

Definition at line 37 of file ctr.cpp.

References set_iv(), Botan::zap(), and Botan::zeroise().

38  {
39  m_cipher->clear();
40  zeroise(m_pad);
41  zeroise(m_counter);
42  zap(m_iv);
43  m_pad_pos = 0;
44  }
void zap(std::vector< T, Alloc > &vec)
Definition: secmem.h:191
void zeroise(std::vector< T, Alloc > &vec)
Definition: secmem.h:181

◆ clone()

CTR_BE* Botan::CTR_BE::clone ( ) const
inlineoverridevirtual
Returns
a new object representing the same algorithm as *this

Implements Botan::StreamCipher.

Definition at line 36 of file ctr.h.

37  { return new CTR_BE(m_cipher->clone(), m_ctr_size); }
CTR_BE(BlockCipher *cipher)
Definition: ctr.cpp:13

◆ create()

std::unique_ptr< StreamCipher > Botan::StreamCipher::create ( const std::string &  algo_spec,
const std::string &  provider = "" 
)
staticinherited

Create an instance based on a name If provider is empty then best available is chosen.

Parameters
algo_specalgorithm name
providerprovider implementation to use
Returns
a null pointer if the algo/provider combination cannot be found

Definition at line 41 of file stream_cipher.cpp.

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_as_integer(), Botan::SCAN_Name::arg_count(), Botan::SCAN_Name::arg_count_between(), BOTAN_UNUSED, Botan::StreamCipher::cipher(), and Botan::BlockCipher::create().

Referenced by Botan::BlockCipher::create(), Botan::StreamCipher::create_or_throw(), Botan::get_cipher_mode(), and Botan::get_stream_cipher().

43  {
44  const SCAN_Name req(algo_spec);
45 
46 #if defined(BOTAN_HAS_CTR_BE)
47  if((req.algo_name() == "CTR-BE" || req.algo_name() == "CTR") && req.arg_count_between(1,2))
48  {
49  if(provider.empty() || provider == "base")
50  {
51  auto cipher = BlockCipher::create(req.arg(0));
52  if(cipher)
53  {
54  size_t ctr_size = req.arg_as_integer(1, cipher->block_size());
55  return std::unique_ptr<StreamCipher>(new CTR_BE(cipher.release(), ctr_size));
56  }
57  }
58  }
59 #endif
60 
61 #if defined(BOTAN_HAS_CHACHA)
62  if(req.algo_name() == "ChaCha")
63  {
64  if(provider.empty() || provider == "base")
65  return std::unique_ptr<StreamCipher>(new ChaCha(req.arg_as_integer(0, 20)));
66  }
67 
68  if(req.algo_name() == "ChaCha20")
69  {
70  if(provider.empty() || provider == "base")
71  return std::unique_ptr<StreamCipher>(new ChaCha(20));
72  }
73 #endif
74 
75 #if defined(BOTAN_HAS_SALSA20)
76  if(req.algo_name() == "Salsa20")
77  {
78  if(provider.empty() || provider == "base")
79  return std::unique_ptr<StreamCipher>(new Salsa20);
80  }
81 #endif
82 
83 #if defined(BOTAN_HAS_SHAKE_CIPHER)
84  if(req.algo_name() == "SHAKE-128")
85  {
86  if(provider.empty() || provider == "base")
87  return std::unique_ptr<StreamCipher>(new SHAKE_128_Cipher);
88  }
89 #endif
90 
91 #if defined(BOTAN_HAS_OFB)
92  if(req.algo_name() == "OFB" && req.arg_count() == 1)
93  {
94  if(provider.empty() || provider == "base")
95  {
96  if(auto c = BlockCipher::create(req.arg(0)))
97  return std::unique_ptr<StreamCipher>(new OFB(c.release()));
98  }
99  }
100 #endif
101 
102 #if defined(BOTAN_HAS_RC4)
103 
104  if(req.algo_name() == "RC4" ||
105  req.algo_name() == "ARC4" ||
106  req.algo_name() == "MARK-4")
107  {
108  const size_t skip = (req.algo_name() == "MARK-4") ? 256 : req.arg_as_integer(0, 0);
109 
110 #if defined(BOTAN_HAS_OPENSSL)
111  if(provider.empty() || provider == "openssl")
112  {
113  return std::unique_ptr<StreamCipher>(make_openssl_rc4(skip));
114  }
115 #endif
116 
117  if(provider.empty() || provider == "base")
118  {
119  return std::unique_ptr<StreamCipher>(new RC4(skip));
120  }
121  }
122 
123 #endif
124 
125  BOTAN_UNUSED(req);
127 
128  return nullptr;
129  }
virtual void cipher(const uint8_t in[], uint8_t out[], size_t len)=0
virtual std::string provider() const
#define BOTAN_UNUSED(...)
Definition: assert.h:106
static std::unique_ptr< BlockCipher > create(const std::string &algo_spec, const std::string &provider="")

◆ create_or_throw()

std::unique_ptr< StreamCipher > Botan::StreamCipher::create_or_throw ( const std::string &  algo_spec,
const std::string &  provider = "" 
)
staticinherited

Create an instance based on a name If provider is empty then best available is chosen.

Parameters
algo_specalgorithm name
providerprovider implementation to use Throws a Lookup_Error if the algo/provider combination cannot be found

Definition at line 133 of file stream_cipher.cpp.

References Botan::StreamCipher::create().

Referenced by Botan::ChaCha_RNG::ChaCha_RNG(), and Botan::make_stream_cipher().

135  {
136  if(auto sc = StreamCipher::create(algo, provider))
137  {
138  return sc;
139  }
140  throw Lookup_Error("Stream cipher", algo, provider);
141  }
virtual std::string provider() const
static std::unique_ptr< StreamCipher > create(const std::string &algo_spec, const std::string &provider="")

◆ decrypt()

template<typename Alloc >
void Botan::StreamCipher::decrypt ( std::vector< uint8_t, Alloc > &  inout)
inlineinherited

Decrypt a message in place The message is decrypted in place.

Parameters
inoutthe plaintext / ciphertext

Definition at line 93 of file stream_cipher.h.

94  { cipher(inout.data(), inout.data(), inout.size()); }
virtual void cipher(const uint8_t in[], uint8_t out[], size_t len)=0

◆ encipher()

template<typename Alloc >
void Botan::StreamCipher::encipher ( std::vector< uint8_t, Alloc > &  inout)
inlineinherited

Encrypt a message The message is encrypted/decrypted in place.

Parameters
inoutthe plaintext / ciphertext

Definition at line 75 of file stream_cipher.h.

76  { cipher(inout.data(), inout.data(), inout.size()); }
virtual void cipher(const uint8_t in[], uint8_t out[], size_t len)=0

◆ encrypt()

template<typename Alloc >
void Botan::StreamCipher::encrypt ( std::vector< uint8_t, Alloc > &  inout)
inlineinherited

Encrypt a message The message is encrypted in place.

Parameters
inoutthe plaintext / ciphertext

Definition at line 84 of file stream_cipher.h.

85  { cipher(inout.data(), inout.data(), inout.size()); }
virtual void cipher(const uint8_t in[], uint8_t out[], size_t len)=0

◆ key_spec()

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

Implements Botan::SymmetricAlgorithm.

Definition at line 29 of file ctr.h.

30  {
31  return m_cipher->key_spec();
32  }

◆ maximum_keylength()

size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const
inlineinherited
Returns
minimum allowed key length

Definition at line 39 of file sym_algo.h.

40  {
41  return key_spec().maximum_keylength();
42  }
size_t maximum_keylength() const
Definition: key_spec.h:69
virtual Key_Length_Specification key_spec() const =0

◆ minimum_keylength()

size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const
inlineinherited
Returns
maximum allowed key length

Definition at line 47 of file sym_algo.h.

48  {
49  return key_spec().minimum_keylength();
50  }
virtual Key_Length_Specification key_spec() const =0
size_t minimum_keylength() const
Definition: key_spec.h:61

◆ name()

std::string Botan::CTR_BE::name ( ) const
overridevirtual
Returns
the algorithm name

Implements Botan::SymmetricAlgorithm.

Definition at line 54 of file ctr.cpp.

References Botan::ASN1::to_string().

Referenced by set_iv().

55  {
56  if(m_ctr_size == m_block_size)
57  return ("CTR-BE(" + m_cipher->name() + ")");
58  else
59  return ("CTR-BE(" + m_cipher->name() + "," + std::to_string(m_ctr_size) + ")");
60 
61  }
std::string to_string(const BER_Object &obj)
Definition: asn1_obj.cpp:108

◆ provider()

virtual std::string Botan::StreamCipher::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::ChaCha.

Definition at line 124 of file stream_cipher.h.

124 { return "base"; }

◆ providers()

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

Definition at line 143 of file stream_cipher.cpp.

Referenced by Botan::TLS::Ciphersuite::by_id(), and Botan::get_stream_cipher_providers().

144  {
145  return probe_providers_of<StreamCipher>(algo_spec, {"base", "openssl"});
146  }

◆ seek()

void Botan::CTR_BE::seek ( uint64_t  offset)
overridevirtual

Set the offset and the state used later to generate the keystream

Parameters
offsetthe offset where we begin to generate the keystream

Implements Botan::StreamCipher.

Definition at line 175 of file ctr.cpp.

References Botan::buffer_insert(), Botan::SymmetricAlgorithm::verify_key_set(), and Botan::zeroise().

Referenced by set_iv().

176  {
177  verify_key_set(m_iv.empty() == false);
178 
179  const uint64_t base_counter = m_ctr_blocks * (offset / m_counter.size());
180 
181  zeroise(m_counter);
182  buffer_insert(m_counter, 0, m_iv);
183 
184  const size_t BS = m_block_size;
185 
186  // Set m_counter blocks to IV, IV + 1, ... IV + n
187  for(size_t i = 1; i != m_ctr_blocks; ++i)
188  {
189  buffer_insert(m_counter, i*BS, &m_counter[(i-1)*BS], BS);
190 
191  for(size_t j = 0; j != m_ctr_size; ++j)
192  if(++m_counter[i*BS + (BS - 1 - j)])
193  break;
194  }
195 
196  if(base_counter > 0)
197  add_counter(base_counter);
198 
199  m_cipher->encrypt_n(m_counter.data(), m_pad.data(), m_ctr_blocks);
200  m_pad_pos = offset % m_counter.size();
201  }
void verify_key_set(bool cond) const
Definition: sym_algo.h:95
size_t buffer_insert(std::vector< T, Alloc > &buf, size_t buf_offset, const T input[], size_t input_length)
Definition: secmem.h:103
void zeroise(std::vector< T, Alloc > &vec)
Definition: secmem.h:181

◆ set_iv()

void Botan::CTR_BE::set_iv ( const uint8_t  iv[],
size_t  iv_len 
)
overridevirtual

Resync the cipher using the IV

Parameters
ivthe initialization vector
iv_lenthe length of the IV in bytes

Implements Botan::StreamCipher.

Definition at line 103 of file ctr.cpp.

References Botan::buffer_insert(), Botan::load_be< uint32_t >(), Botan::load_be< uint64_t >(), name(), seek(), Botan::store_be(), valid_iv_length(), and Botan::zeroise().

Referenced by clear().

104  {
105  if(!valid_iv_length(iv_len))
106  throw Invalid_IV_Length(name(), iv_len);
107 
108  m_iv.resize(m_cipher->block_size());
109  zeroise(m_iv);
110  buffer_insert(m_iv, 0, iv, iv_len);
111 
112  seek(0);
113  }
std::string name() const override
Definition: ctr.cpp:54
void seek(uint64_t offset) override
Definition: ctr.cpp:175
size_t buffer_insert(std::vector< T, Alloc > &buf, size_t buf_offset, const T input[], size_t input_length)
Definition: secmem.h:103
bool valid_iv_length(size_t iv_len) const override
Definition: ctr.h:26
void zeroise(std::vector< T, Alloc > &vec)
Definition: secmem.h:181

◆ set_key() [1/3]

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

Set the symmetric key of this object.

Parameters
keythe SymmetricKey to be set.

Definition at line 66 of file sym_algo.h.

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

Referenced by Botan::aont_package(), Botan::aont_unpackage(), botan_block_cipher_set_key(), botan_mac_set_key(), Botan::GOST_34_11::copy_state(), Botan::DESX::decrypt_n(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec(), Botan::pbkdf2(), and Botan::TLS_PRF::TLS_PRF().

67  {
68  set_key(key.begin(), key.length());
69  }
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:66

◆ set_key() [2/3]

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

Definition at line 72 of file sym_algo.h.

73  {
74  set_key(key.data(), key.size());
75  }
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:66

◆ set_key() [3/3]

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

Set the symmetric key of this object.

Parameters
keythe to be set as a byte array.
lengthin bytes of key param

Definition at line 82 of file sym_algo.h.

83  {
84  if(!valid_keylength(length))
85  throw Invalid_Key_Length(name(), length);
86  key_schedule(key, length);
87  }
bool valid_keylength(size_t length) const
Definition: sym_algo.h:57
virtual std::string name() const =0

◆ valid_iv_length()

bool Botan::CTR_BE::valid_iv_length ( size_t  iv_len) const
inlineoverridevirtual
Parameters
iv_lenthe length of the IV in bytes
Returns
if the length is valid for this algorithm

Reimplemented from Botan::StreamCipher.

Definition at line 26 of file ctr.h.

Referenced by set_iv().

27  { return (iv_len <= m_cipher->block_size()); }

◆ valid_keylength()

bool Botan::SymmetricAlgorithm::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 57 of file sym_algo.h.

Referenced by Botan::aont_package(), and Botan::aont_unpackage().

58  {
59  return key_spec().valid_keylength(length);
60  }
bool valid_keylength(size_t length) const
Definition: key_spec.h:51
virtual Key_Length_Specification key_spec() const =0

◆ verify_key_set()

void Botan::SymmetricAlgorithm::verify_key_set ( bool  cond) const
inlineprotectedinherited

Definition at line 95 of file sym_algo.h.

Referenced by Botan::Salsa20::cipher(), cipher(), Botan::RC4::cipher(), Botan::SHAKE_128_Cipher::cipher(), Botan::ChaCha::cipher(), Botan::Poly1305::clear(), Botan::CAST_256::decrypt_n(), Botan::Twofish::decrypt_n(), Botan::DESX::decrypt_n(), Botan::DES::decrypt_n(), Botan::CAST_128::decrypt_n(), Botan::Threefish_512::decrypt_n(), Botan::MISTY1::decrypt_n(), Botan::SEED::decrypt_n(), Botan::SHACAL2::decrypt_n(), Botan::Noekeon::decrypt_n(), Botan::KASUMI::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::SM4::decrypt_n(), Botan::XTEA::decrypt_n(), Botan::Blowfish::decrypt_n(), Botan::Serpent::decrypt_n(), Botan::Lion::decrypt_n(), Botan::TripleDES::decrypt_n(), Botan::GOST_28147_89::decrypt_n(), Botan::CAST_128::encrypt_n(), Botan::Noekeon::encrypt_n(), Botan::XTEA::encrypt_n(), Botan::MISTY1::encrypt_n(), Botan::Twofish::encrypt_n(), Botan::SHACAL2::encrypt_n(), Botan::SEED::encrypt_n(), Botan::SM4::encrypt_n(), Botan::DES::encrypt_n(), Botan::CAST_256::encrypt_n(), Botan::DESX::encrypt_n(), Botan::IDEA::encrypt_n(), Botan::Threefish_512::encrypt_n(), Botan::Blowfish::encrypt_n(), Botan::KASUMI::encrypt_n(), Botan::Serpent::encrypt_n(), Botan::Lion::encrypt_n(), Botan::TripleDES::encrypt_n(), Botan::GOST_28147_89::encrypt_n(), Botan::Salsa20::seek(), seek(), Botan::ChaCha::seek(), and Botan::GHASH::update_associated_data().

96  {
97  if(cond == false)
98  throw Key_Not_Set(name());
99  }
virtual std::string name() const =0

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