Botan 3.0.0
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
Botan::XTS_Mode Class Referenceabstract

#include <xts.h>

Inheritance diagram for Botan::XTS_Mode:
Botan::Cipher_Mode Botan::SymmetricAlgorithm Botan::XTS_Decryption Botan::XTS_Encryption

Public Member Functions

bool authenticated () const
 
void clear () override final
 
size_t default_nonce_length () const override final
 
void finish (secure_vector< uint8_t > &final_block, size_t offset=0)
 
template<concepts::resizable_byte_buffer T>
void finish (T &final_block, size_t offset=0)
 
bool has_keying_material () const override final
 
size_t ideal_granularity () const override final
 
Key_Length_Specification key_spec () const override final
 
size_t maximum_keylength () const
 
size_t minimum_final_size () const override final
 
size_t minimum_keylength () const
 
std::string name () const override final
 
virtual size_t output_length (size_t input_length) const =0
 
size_t process (std::span< uint8_t > msg)
 
size_t process (uint8_t msg[], size_t msg_len)
 
virtual std::string provider () const
 
virtual bool requires_entire_message () const
 
void reset () override final
 
void set_key (const SymmetricKey &key)
 
void set_key (const uint8_t key[], size_t length)
 
void set_key (std::span< const uint8_t > key)
 
void start ()
 
void start (const uint8_t nonce[], size_t nonce_len)
 
void start (std::span< const uint8_t > nonce)
 
virtual size_t tag_size () const
 
template<concepts::resizable_byte_buffer T>
void update (T &buffer, size_t offset=0)
 
size_t update_granularity () const override final
 
bool valid_keylength (size_t length) const
 
bool valid_nonce_length (size_t n) const override final
 

Static Public Member Functions

static std::unique_ptr< Cipher_Modecreate (std::string_view algo, Cipher_Dir direction, std::string_view provider="")
 
static std::unique_ptr< Cipher_Modecreate_or_throw (std::string_view algo, Cipher_Dir direction, std::string_view provider="")
 
static std::vector< std::string > providers (std::string_view algo_spec)
 

Protected Member Functions

void assert_key_material_set () const
 
void assert_key_material_set (bool predicate) const
 
const BlockCiphercipher () const
 
size_t cipher_block_size () const
 
virtual void finish_msg (secure_vector< uint8_t > &final_block, size_t offset=0)=0
 
virtual size_t process_msg (uint8_t msg[], size_t msg_len)=0
 
const uint8_t * tweak () const
 
size_t tweak_blocks () const
 
bool tweak_set () const
 
void update_tweak (size_t last_used)
 
 XTS_Mode (std::unique_ptr< BlockCipher > cipher)
 

Detailed Description

IEEE P1619 XTS Mode

Definition at line 20 of file xts.h.

Constructor & Destructor Documentation

◆ XTS_Mode()

Botan::XTS_Mode::XTS_Mode ( std::unique_ptr< BlockCipher cipher)
explicitprotected

Definition at line 15 of file xts.cpp.

15 :
16 m_cipher(std::move(cipher)),
17 m_cipher_block_size(m_cipher->block_size()),
18 m_cipher_parallelism(m_cipher->parallel_bytes()),
19 m_tweak_blocks(m_cipher_parallelism / m_cipher_block_size)
20 {
21 if(poly_double_supported_size(m_cipher_block_size) == false)
22 {
23 throw Invalid_Argument(fmt("Cannot use {} with XTS", m_cipher->name()));
24 }
25
26 m_tweak_cipher = m_cipher->new_object();
27 }
const BlockCipher & cipher() const
Definition: xts.h:51
std::string fmt(std::string_view format, const T &... args)
Definition: fmt.h:60
bool poly_double_supported_size(size_t n)
Definition: poly_dbl.h:22

References Botan::fmt(), and Botan::poly_double_supported_size().

Member Function Documentation

◆ assert_key_material_set() [1/2]

void Botan::SymmetricAlgorithm::assert_key_material_set ( ) const
inlineprotectedinherited

Definition at line 182 of file sym_algo.h.

183 {
185 }
virtual bool has_keying_material() const =0
void assert_key_material_set() const
Definition: sym_algo.h:182

Referenced by Botan::Salsa20::cipher_bytes(), Botan::AES_128::decrypt_n(), Botan::AES_192::decrypt_n(), Botan::AES_256::decrypt_n(), Botan::ARIA_128::decrypt_n(), Botan::ARIA_192::decrypt_n(), Botan::ARIA_256::decrypt_n(), Botan::Blowfish::decrypt_n(), Botan::Camellia_128::decrypt_n(), Botan::Camellia_192::decrypt_n(), Botan::Camellia_256::decrypt_n(), Botan::CAST_128::decrypt_n(), Botan::DES::decrypt_n(), Botan::TripleDES::decrypt_n(), Botan::GOST_28147_89::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::Lion::decrypt_n(), Botan::Noekeon::decrypt_n(), Botan::SEED::decrypt_n(), Botan::Serpent::decrypt_n(), Botan::SHACAL2::decrypt_n(), Botan::SM4::decrypt_n(), Botan::Threefish_512::decrypt_n(), Botan::Twofish::decrypt_n(), Botan::AES_128::encrypt_n(), Botan::AES_192::encrypt_n(), Botan::AES_256::encrypt_n(), Botan::ARIA_128::encrypt_n(), Botan::ARIA_192::encrypt_n(), Botan::ARIA_256::encrypt_n(), Botan::Blowfish::encrypt_n(), Botan::Camellia_128::encrypt_n(), Botan::Camellia_192::encrypt_n(), Botan::Camellia_256::encrypt_n(), Botan::CAST_128::encrypt_n(), Botan::DES::encrypt_n(), Botan::TripleDES::encrypt_n(), Botan::GOST_28147_89::encrypt_n(), Botan::IDEA::encrypt_n(), Botan::Lion::encrypt_n(), Botan::Noekeon::encrypt_n(), Botan::SEED::encrypt_n(), Botan::Serpent::encrypt_n(), Botan::SHACAL2::encrypt_n(), Botan::SM4::encrypt_n(), Botan::Threefish_512::encrypt_n(), Botan::Twofish::encrypt_n(), Botan::GHASH::final(), Botan::GHASH::ghash_update(), Botan::ChaCha::seek(), Botan::CTR_BE::seek(), Botan::Salsa20::seek(), Botan::OCB_Mode::set_associated_data_n(), Botan::Salsa20::set_iv_bytes(), Botan::GHASH::update(), and Botan::GHASH::update_associated_data().

◆ assert_key_material_set() [2/2]

void Botan::SymmetricAlgorithm::assert_key_material_set ( bool  predicate) const
inlineprotectedinherited

Definition at line 187 of file sym_algo.h.

188 {
189 if(!predicate)
190 throw_key_not_set_error();
191 }

◆ authenticated()

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

Definition at line 239 of file cipher_mode.h.

239{ return this->tag_size() > 0; }
virtual size_t tag_size() const
Definition: cipher_mode.h:244

◆ cipher()

const BlockCipher & Botan::XTS_Mode::cipher ( ) const
inlineprotected

Definition at line 51 of file xts.h.

51{ return *m_cipher; }

Referenced by key_spec(), and name().

◆ cipher_block_size()

size_t Botan::XTS_Mode::cipher_block_size ( ) const
inlineprotected

Definition at line 55 of file xts.h.

55{ return m_cipher_block_size; }

Referenced by default_nonce_length(), minimum_final_size(), and valid_nonce_length().

◆ clear()

void Botan::XTS_Mode::clear ( )
finaloverridevirtual

Reset the internal state. This includes not just the key, but any partial message that may have been in process.

Implements Botan::SymmetricAlgorithm.

Definition at line 29 of file xts.cpp.

30 {
31 m_cipher->clear();
32 m_tweak_cipher->clear();
33 reset();
34 }
void reset() override final
Definition: xts.cpp:46

References reset().

◆ create()

std::unique_ptr< Cipher_Mode > Botan::Cipher_Mode::create ( std::string_view  algo,
Cipher_Dir  direction,
std::string_view  provider = "" 
)
staticinherited

Create an AEAD mode

Parameters
algothe algorithm to create
directionspecify if this should be an encryption or decryption AEAD
provideroptional specification for provider to use
Returns
an AEAD mode or a null pointer if not available

Definition at line 50 of file cipher_mode.cpp.

53 {
54#if defined(BOTAN_HAS_COMMONCRYPTO)
55 if(provider.empty() || provider == "commoncrypto")
56 {
57 auto commoncrypto_cipher = make_commoncrypto_cipher_mode(algo, direction);
58
59 if(commoncrypto_cipher)
60 return commoncrypto_cipher;
61
62 if(!provider.empty())
63 return std::unique_ptr<Cipher_Mode>();
64 }
65#endif
66
67#if defined(BOTAN_HAS_STREAM_CIPHER)
68 if(auto sc = StreamCipher::create(algo))
69 {
70 return std::make_unique<Stream_Cipher_Mode>(std::move(sc));
71 }
72#endif
73
74#if defined(BOTAN_HAS_AEAD_MODES)
75 if(auto aead = AEAD_Mode::create(algo, direction))
76 {
77 return aead;
78 }
79#endif
80
81 if(algo.find('/') != std::string::npos)
82 {
83 const std::vector<std::string> algo_parts = split_on(algo, '/');
84 std::string_view cipher_name = algo_parts[0];
85 const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
86
87 if(mode_info.empty())
88 return std::unique_ptr<Cipher_Mode>();
89
90 std::ostringstream mode_name;
91
92 mode_name << mode_info[0] << '(' << cipher_name;
93 for(size_t i = 1; i < mode_info.size(); ++i)
94 mode_name << ',' << mode_info[i];
95 for(size_t i = 2; i < algo_parts.size(); ++i)
96 mode_name << ',' << algo_parts[i];
97 mode_name << ')';
98
99 return Cipher_Mode::create(mode_name.str(), direction, provider);
100 }
101
102#if defined(BOTAN_HAS_BLOCK_CIPHER)
103
104 SCAN_Name spec(algo);
105
106 if(spec.arg_count() == 0)
107 {
108 return std::unique_ptr<Cipher_Mode>();
109 }
110
111 auto bc = BlockCipher::create(spec.arg(0), provider);
112
113 if(!bc)
114 {
115 return std::unique_ptr<Cipher_Mode>();
116 }
117
118#if defined(BOTAN_HAS_MODE_CBC)
119 if(spec.algo_name() == "CBC")
120 {
121 const std::string padding = spec.arg(1, "PKCS7");
122
123 if(padding == "CTS")
124 {
125 if(direction == Cipher_Dir::Encryption)
126 return std::make_unique<CTS_Encryption>(std::move(bc));
127 else
128 return std::make_unique<CTS_Decryption>(std::move(bc));
129 }
130 else
131 {
132 auto pad = BlockCipherModePaddingMethod::create(padding);
133
134 if(pad)
135 {
136 if(direction == Cipher_Dir::Encryption)
137 return std::make_unique<CBC_Encryption>(std::move(bc), std::move(pad));
138 else
139 return std::make_unique<CBC_Decryption>(std::move(bc), std::move(pad));
140 }
141 }
142 }
143#endif
144
145#if defined(BOTAN_HAS_MODE_XTS)
146 if(spec.algo_name() == "XTS")
147 {
148 if(direction == Cipher_Dir::Encryption)
149 return std::make_unique<XTS_Encryption>(std::move(bc));
150 else
151 return std::make_unique<XTS_Decryption>(std::move(bc));
152 }
153#endif
154
155#if defined(BOTAN_HAS_MODE_CFB)
156 if(spec.algo_name() == "CFB")
157 {
158 const size_t feedback_bits = spec.arg_as_integer(1, 8*bc->block_size());
159 if(direction == Cipher_Dir::Encryption)
160 return std::make_unique<CFB_Encryption>(std::move(bc), feedback_bits);
161 else
162 return std::make_unique<CFB_Decryption>(std::move(bc), feedback_bits);
163 }
164#endif
165
166#endif
167
168 return std::unique_ptr<Cipher_Mode>();
169 }
static std::unique_ptr< AEAD_Mode > create(std::string_view algo, Cipher_Dir direction, std::string_view provider="")
Definition: aead.cpp:52
static std::unique_ptr< BlockCipherModePaddingMethod > create(std::string_view algo_spec)
Definition: mode_pad.cpp:19
static std::unique_ptr< BlockCipher > create(std::string_view algo_spec, std::string_view provider="")
static std::unique_ptr< Cipher_Mode > create(std::string_view algo, Cipher_Dir direction, std::string_view provider="")
Definition: cipher_mode.cpp:50
virtual std::string provider() const
Definition: cipher_mode.h:250
static std::unique_ptr< StreamCipher > create(std::string_view algo_spec, std::string_view provider="")
std::vector< std::string > split_on(std::string_view str, char delim)
Definition: parsing.cpp:117
std::unique_ptr< Cipher_Mode > make_commoncrypto_cipher_mode(std::string_view name, Cipher_Dir direction)
std::vector< std::string > parse_algorithm_name(std::string_view namex)
Definition: parsing.cpp:61

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_as_integer(), Botan::SCAN_Name::arg_count(), Botan::AEAD_Mode::create(), Botan::Cipher_Mode::create(), Botan::BlockCipherModePaddingMethod::create(), Botan::BlockCipher::create(), Botan::StreamCipher::create(), Botan::Encryption, Botan::make_commoncrypto_cipher_mode(), Botan::parse_algorithm_name(), Botan::Cipher_Mode::provider(), and Botan::split_on().

Referenced by botan_cipher_init(), Botan::Cipher_Mode::create(), Botan::Cipher_Mode::create_or_throw(), Botan::get_cipher_mode(), Botan::pbes2_decrypt(), and Botan::Cipher_Mode::providers().

◆ create_or_throw()

std::unique_ptr< Cipher_Mode > Botan::Cipher_Mode::create_or_throw ( std::string_view  algo,
Cipher_Dir  direction,
std::string_view  provider = "" 
)
staticinherited

Create an AEAD mode, or throw

Parameters
algothe algorithm to create
directionspecify if this should be an encryption or decryption AEAD
provideroptional specification for provider to use
Returns
an AEAD mode, or throw an exception

Definition at line 40 of file cipher_mode.cpp.

43 {
44 if(auto mode = Cipher_Mode::create(algo, direction, provider))
45 return mode;
46
47 throw Lookup_Error("Cipher mode", algo, provider);
48 }

References Botan::Cipher_Mode::create(), and Botan::Cipher_Mode::provider().

Referenced by Botan::ECIES_System_Params::create_cipher(), Botan::CryptoBox::decrypt_bin(), Botan::CryptoBox::encrypt(), and Botan::get_cipher().

◆ default_nonce_length()

size_t Botan::XTS_Mode::default_nonce_length ( ) const
finaloverridevirtual
Returns
the default size for a nonce

Implements Botan::Cipher_Mode.

Definition at line 66 of file xts.cpp.

67 {
68 return cipher_block_size();
69 }
size_t cipher_block_size() const
Definition: xts.h:55

References cipher_block_size().

◆ finish() [1/2]

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

Complete processing of a message.

Parameters
final_blockin/out parameter which must be at least minimum_final_size() bytes, and will be set to any final output
offsetan offset into final_block to begin processing

Definition at line 158 of file cipher_mode.h.

159 {
160 finish_msg(final_block, offset);
161 }
virtual void finish_msg(secure_vector< uint8_t > &final_block, size_t offset=0)=0

Referenced by botan_cipher_update(), and Botan::TLS::write_record().

◆ finish() [2/2]

template<concepts::resizable_byte_buffer T>
void Botan::Cipher_Mode::finish ( T final_block,
size_t  offset = 0 
)
inlineinherited

Complete procession of a message.

Note: Using this overload with anything but a Botan::secure_vector<> is copying the bytes in the in/out buffer.

Parameters
final_blockin/out parameter which must be at least minimum_final_size() bytes, and will be set to any final output
offsetan offset into final_block to begin processing

Definition at line 174 of file cipher_mode.h.

175 {
176 Botan::secure_vector<uint8_t> tmp(final_block.begin(), final_block.end());
177 finish_msg(tmp, offset);
178 final_block.resize(tmp.size());
179 std::copy(tmp.begin(), tmp.end(), final_block.begin());
180 }
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:64

◆ finish_msg()

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

◆ has_keying_material()

bool Botan::XTS_Mode::has_keying_material ( ) const
finaloverridevirtual
Returns
true if a key has been set on this object

Implements Botan::SymmetricAlgorithm.

Definition at line 76 of file xts.cpp.

77 {
78 return m_cipher->has_keying_material() &&
79 m_tweak_cipher->has_keying_material();
80 }

◆ ideal_granularity()

size_t Botan::XTS_Mode::ideal_granularity ( ) const
finaloverridevirtual

Return an ideal granularity. This will be a multiple of the result of update_granularity but may be larger. If so it indicates that better performance may be achieved by providing buffers that are at least that size.

Implements Botan::Cipher_Mode.

Definition at line 41 of file xts.cpp.

42 {
43 return m_cipher_parallelism;
44 }

◆ key_spec()

Key_Length_Specification Botan::XTS_Mode::key_spec ( ) const
finaloverridevirtual
Returns
object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 61 of file xts.cpp.

62 {
63 return cipher().key_spec().multiple(2);
64 }
Key_Length_Specification multiple(size_t n) const
Definition: sym_algo.h:90
virtual Key_Length_Specification key_spec() const =0

References cipher(), Botan::SymmetricAlgorithm::key_spec(), and Botan::Key_Length_Specification::multiple().

◆ maximum_keylength()

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

Definition at line 123 of file sym_algo.h.

124 {
125 return key_spec().maximum_keylength();
126 }
size_t maximum_keylength() const
Definition: sym_algo.h:72

◆ minimum_final_size()

size_t Botan::XTS_Mode::minimum_final_size ( ) const
finaloverridevirtual
Returns
required minimium size to finalize() - may be any length larger than this.

Implements Botan::Cipher_Mode.

Definition at line 56 of file xts.cpp.

57 {
58 return cipher_block_size();
59 }

References cipher_block_size().

◆ minimum_keylength()

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

Definition at line 131 of file sym_algo.h.

132 {
133 return key_spec().minimum_keylength();
134 }
size_t minimum_keylength() const
Definition: sym_algo.h:64

◆ name()

std::string Botan::XTS_Mode::name ( ) const
finaloverridevirtual
Returns
the algorithm name

Implements Botan::SymmetricAlgorithm.

Definition at line 51 of file xts.cpp.

52 {
53 return cipher().name() + "/XTS";
54 }
virtual std::string name() const =0

References cipher(), and Botan::SymmetricAlgorithm::name().

◆ output_length()

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

◆ process() [1/2]

size_t Botan::Cipher_Mode::process ( std::span< uint8_t >  msg)
inlineinherited

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
Returns
bytes written in-place

Definition at line 133 of file cipher_mode.h.

134 { return this->process_msg(msg.data(), msg.size()); }
virtual size_t process_msg(uint8_t msg[], size_t msg_len)=0

◆ process() [2/2]

size_t Botan::Cipher_Mode::process ( uint8_t  msg[],
size_t  msg_len 
)
inlineinherited

Definition at line 135 of file cipher_mode.h.

136 { return this->process_msg(msg, msg_len); }

◆ process_msg()

virtual size_t Botan::Cipher_Mode::process_msg ( uint8_t  msg[],
size_t  msg_len 
)
protectedpure virtualinherited

◆ 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 250 of file cipher_mode.h.

250{ return "base"; }

Referenced by Botan::AEAD_Mode::create(), Botan::Cipher_Mode::create(), Botan::AEAD_Mode::create_or_throw(), and Botan::Cipher_Mode::create_or_throw().

◆ providers()

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

Definition at line 172 of file cipher_mode.cpp.

173 {
174 const std::vector<std::string>& possible = { "base", "commoncrypto" };
175 std::vector<std::string> providers;
176 for(auto&& prov : possible)
177 {
178 auto mode = Cipher_Mode::create(algo_spec, Cipher_Dir::Encryption, prov);
179 if(mode)
180 {
181 providers.push_back(prov); // available
182 }
183 }
184 return providers;
185 }
static std::vector< std::string > providers(std::string_view algo_spec)

References Botan::Cipher_Mode::create(), Botan::Encryption, and Botan::Cipher_Mode::providers().

Referenced by Botan::Cipher_Mode::providers().

◆ requires_entire_message()

virtual bool Botan::Cipher_Mode::requires_entire_message ( ) const
inlinevirtualinherited

Certain modes require the entire message be available before any processing can occur. For such modes, input will be consumed but not returned, until finish is called, which returns the entire message.

This function returns true if this mode has this style of operation.

Reimplemented in Botan::CCM_Mode, and Botan::SIV_Mode.

Definition at line 212 of file cipher_mode.h.

212{ return false; }

◆ reset()

void Botan::XTS_Mode::reset ( )
finaloverridevirtual

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

Implements Botan::Cipher_Mode.

Definition at line 46 of file xts.cpp.

47 {
48 m_tweak.clear();
49 }

Referenced by clear().

◆ set_key() [1/3]

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

◆ set_key() [2/3]

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

Set the symmetric key of this object.

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

Definition at line 17 of file sym_algo.cpp.

18 {
19 if(!valid_keylength(length))
20 throw Invalid_Key_Length(name(), length);
21 key_schedule(key, length);
22 }
bool valid_keylength(size_t length) const
Definition: sym_algo.h:141

References Botan::SymmetricAlgorithm::name(), and Botan::SymmetricAlgorithm::valid_keylength().

◆ set_key() [3/3]

void Botan::SymmetricAlgorithm::set_key ( std::span< const uint8_t >  key)
inlineinherited

Set the symmetric key of this object.

Parameters
keythe contiguous byte range to be set.

Definition at line 159 of file sym_algo.h.

160 {
161 set_key(key.data(), key.size());
162 }

◆ start() [1/3]

void Botan::Cipher_Mode::start ( )
inlineinherited

Begin processing a message.

The exact semantics of this depend on the mode. For many modes, the call will fail since a nonce must be provided.

For certain modes such as CBC this will instead cause the last ciphertext block to be used as the nonce of the new message; doing this isn't a good idea, but some (mostly older) protocols do this.

Definition at line 115 of file cipher_mode.h.

116 {
117 return start_msg(nullptr, 0);
118 }
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 with a fresh nonce.

Parameters
noncethe per message nonce
nonce_lenlength of nonce

Definition at line 100 of file cipher_mode.h.

101 {
102 start_msg(nonce, nonce_len);
103 }

◆ start() [3/3]

void Botan::Cipher_Mode::start ( std::span< const uint8_t >  nonce)
inlineinherited

Begin processing a message with a fresh nonce.

Parameters
noncethe per message nonce

Definition at line 90 of file cipher_mode.h.

91 {
92 start_msg(nonce.data(), nonce.size());
93 }

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

◆ tag_size()

virtual size_t Botan::Cipher_Mode::tag_size ( ) const
inlinevirtualinherited
Returns
the size of the authentication tag used (in bytes)

Reimplemented in Botan::ChaCha20Poly1305_Mode, Botan::CCM_Mode, Botan::EAX_Mode, Botan::GCM_Mode, Botan::OCB_Mode, Botan::SIV_Mode, and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode.

Definition at line 244 of file cipher_mode.h.

244{ return 0; }

◆ tweak()

const uint8_t * Botan::XTS_Mode::tweak ( ) const
inlineprotected

Definition at line 45 of file xts.h.

45{ return m_tweak.data(); }

◆ tweak_blocks()

size_t Botan::XTS_Mode::tweak_blocks ( ) const
inlineprotected

Definition at line 49 of file xts.h.

49{ return m_tweak_blocks; }

Referenced by update_tweak().

◆ tweak_set()

bool Botan::XTS_Mode::tweak_set ( ) const
inlineprotected

Definition at line 47 of file xts.h.

47{ return m_tweak.empty() == false; }

◆ update()

template<concepts::resizable_byte_buffer T>
void Botan::Cipher_Mode::update ( 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 144 of file cipher_mode.h.

145 {
146 BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
147 const size_t written = process(std::span(buffer).subspan(offset));
148 buffer.resize(offset + written);
149 }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:54
size_t process(std::span< uint8_t > msg)
Definition: cipher_mode.h:133

References BOTAN_ASSERT.

Referenced by botan_cipher_update().

◆ update_granularity()

size_t Botan::XTS_Mode::update_granularity ( ) const
finaloverridevirtual
Returns
size of required blocks to update

Implements Botan::Cipher_Mode.

Definition at line 36 of file xts.cpp.

37 {
38 return m_cipher_block_size;
39 }

◆ update_tweak()

void Botan::XTS_Mode::update_tweak ( size_t  last_used)
protected

Definition at line 106 of file xts.cpp.

107 {
108 const size_t BS = m_tweak_cipher->block_size();
109
110 if(which > 0)
111 poly_double_n_le(m_tweak.data(), &m_tweak[(which-1)*BS], BS);
112
113 const size_t blocks_in_tweak = tweak_blocks();
114
115 for(size_t i = 1; i < blocks_in_tweak; ++i)
116 poly_double_n_le(&m_tweak[i*BS], &m_tweak[(i-1)*BS], BS);
117 }
size_t tweak_blocks() const
Definition: xts.h:49
void poly_double_n_le(uint8_t out[], const uint8_t in[], size_t n)
Definition: poly_dbl.cpp:96

References Botan::poly_double_n_le(), and tweak_blocks().

◆ 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 141 of file sym_algo.h.

142 {
143 return key_spec().valid_keylength(length);
144 }
bool valid_keylength(size_t length) const
Definition: sym_algo.h:54

Referenced by Botan::SymmetricAlgorithm::set_key().

◆ valid_nonce_length()

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

Implements Botan::Cipher_Mode.

Definition at line 71 of file xts.cpp.

72 {
73 return n <= cipher_block_size();
74 }

References cipher_block_size().


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