Botan 3.5.0
Crypto and TLS for C&
Botan::OCB_Mode Class Referenceabstract

#include <ocb.h>

Inheritance diagram for Botan::OCB_Mode:
Botan::AEAD_Mode Botan::Cipher_Mode Botan::SymmetricAlgorithm Botan::OCB_Decryption Botan::OCB_Encryption

Public Member Functions

virtual bool associated_data_requires_key () const
 
bool authenticated () const
 
void clear () override final
 
size_t default_nonce_length () const override
 
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
 
virtual size_t maximum_associated_data_inputs () const
 
size_t maximum_keylength () const
 
virtual size_t minimum_final_size () const =0
 
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_ad (std::span< const uint8_t > ad)
 
void set_associated_data (const uint8_t ad[], size_t ad_len)
 
void set_associated_data (std::span< const uint8_t > ad)
 
void set_associated_data_n (size_t idx, std::span< const uint8_t > ad) override final
 
template<typename Alloc >
void set_associated_data_vec (const std::vector< uint8_t, Alloc > &ad)
 
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)
 
size_t tag_size () const override final
 
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) const override final
 
 ~OCB_Mode ()
 

Static Public Member Functions

static std::unique_ptr< AEAD_Modecreate (std::string_view algo, Cipher_Dir direction, std::string_view provider="")
 
static std::unique_ptr< AEAD_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
 
size_t block_size () const
 
virtual void finish_msg (secure_vector< uint8_t > &final_block, size_t offset=0)=0
 
 OCB_Mode (std::unique_ptr< BlockCipher > cipher, size_t tag_size)
 
size_t par_blocks () const
 
size_t par_bytes () const
 
virtual size_t process_msg (uint8_t msg[], size_t msg_len)=0
 

Protected Attributes

secure_vector< uint8_t > m_ad_hash
 
size_t m_block_index = 0
 
secure_vector< uint8_t > m_checksum
 
std::unique_ptr< BlockCipherm_cipher
 
std::unique_ptr< L_computer > m_L
 

Detailed Description

OCB Mode (base class for OCB_Encryption and OCB_Decryption). OCB was previously patented in the United States but the patent has now been allowed to lapse.

See also
"The OCB Authenticated-Encryption Algorithm" RFC 7253 https://tools.ietf.org/html/rfc7253
"OCB For Block Ciphers Without 128-Bit Blocks" (draft-krovetz-ocb-wide-d3) for the extension of OCB to Block Ciphers ciphers with larger Block Ciphers sizes.
https://mailarchive.ietf.org/arch/msg/cfrg/qLTveWOdTJcLn4HP3ev-vrj05Vg/

Definition at line 31 of file ocb.h.

Constructor & Destructor Documentation

◆ ~OCB_Mode()

Botan::OCB_Mode::~OCB_Mode ( )
default

◆ OCB_Mode()

Botan::OCB_Mode::OCB_Mode ( std::unique_ptr< BlockCipher > cipher,
size_t tag_size )
protected
Parameters
cipherthe block cipher to use
tag_sizeis how big the auth tag will be

Definition at line 160 of file ocb.cpp.

160 :
161 m_cipher(std::move(cipher)),
162 m_checksum(m_cipher->parallel_bytes()),
163 m_ad_hash(m_cipher->block_size()),
164 m_tag_size(tag_size),
165 m_block_size(m_cipher->block_size()),
166 m_par_blocks(m_cipher->parallel_bytes() / m_block_size) {
167 const size_t BS = block_size();
168
169 /*
170 * draft-krovetz-ocb-wide-d1 specifies OCB for several other block
171 * sizes but only 128, 192, 256 and 512 bit are currently supported
172 * by this implementation.
173 */
174 BOTAN_ARG_CHECK(BS == 16 || BS == 24 || BS == 32 || BS == 64, "Invalid block size for OCB");
175
176 BOTAN_ARG_CHECK(m_tag_size % 4 == 0 && m_tag_size >= 8 && m_tag_size <= BS && m_tag_size <= 32,
177 "Invalid OCB tag length");
178}
#define BOTAN_ARG_CHECK(expr, msg)
Definition assert.h:29
size_t block_size() const
Definition ocb.h:62
size_t tag_size() const override final
Definition ocb.h:45
secure_vector< uint8_t > m_checksum
Definition ocb.h:74
std::unique_ptr< BlockCipher > m_cipher
Definition ocb.h:69
secure_vector< uint8_t > m_ad_hash
Definition ocb.h:75

References block_size(), and BOTAN_ARG_CHECK.

Member Function Documentation

◆ assert_key_material_set() [1/2]

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

Definition at line 139 of file sym_algo.h.

virtual bool has_keying_material() const =0
void assert_key_material_set() const
Definition sym_algo.h:139

References Botan::SymmetricAlgorithm::assert_key_material_set().

Referenced by Botan::SymmetricAlgorithm::assert_key_material_set(), 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::GOST_28147_89::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::Kuznyechik::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::TripleDES::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::GOST_28147_89::encrypt_n(), Botan::IDEA::encrypt_n(), Botan::Kuznyechik::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::TripleDES::encrypt_n(), Botan::Twofish::encrypt_n(), Botan::GHASH::final(), Botan::GHASH::ghash_update(), Botan::ChaCha::seek(), Botan::CTR_BE::seek(), Botan::Salsa20::seek(), 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 141 of file sym_algo.h.

141 {
142 if(!predicate) {
143 throw_key_not_set_error();
144 }
145 }

◆ associated_data_requires_key()

virtual bool Botan::AEAD_Mode::associated_data_requires_key ( ) const
inlinevirtualinherited

Most AEADs require the key to be set prior to setting the AD A few allow the AD to be set even before the cipher is keyed. Such ciphers would return false from this function.

Reimplemented in Botan::CCM_Mode, and Botan::ChaCha20Poly1305_Mode.

Definition at line 98 of file aead.h.

98{ return true; }

◆ authenticated()

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

Definition at line 223 of file cipher_mode.h.

223{ return this->tag_size() > 0; }
virtual size_t tag_size() const

◆ block_size()

size_t Botan::OCB_Mode::block_size ( ) const
inlineprotected

Definition at line 62 of file ocb.h.

62{ return m_block_size; }

Referenced by ideal_granularity(), OCB_Mode(), update_granularity(), and valid_nonce_length().

◆ clear()

void Botan::OCB_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 182 of file ocb.cpp.

182 {
183 m_cipher->clear();
184 m_L.reset(); // add clear here?
185 reset();
186}
void reset() override final
Definition ocb.cpp:188
std::unique_ptr< L_computer > m_L
Definition ocb.h:70

References m_cipher, m_L, and reset().

◆ create()

std::unique_ptr< AEAD_Mode > Botan::AEAD_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 53 of file aead.cpp.

53 {
55#if defined(BOTAN_HAS_AEAD_CHACHA20_POLY1305)
56 if(algo == "ChaCha20Poly1305") {
57 if(dir == Cipher_Dir::Encryption) {
58 return std::make_unique<ChaCha20Poly1305_Encryption>();
59 } else {
60 return std::make_unique<ChaCha20Poly1305_Decryption>();
61 }
62 }
63#endif
64
65 if(algo.find('/') != std::string::npos) {
66 const std::vector<std::string> algo_parts = split_on(algo, '/');
67 std::string_view cipher_name = algo_parts[0];
68 const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
69
70 if(mode_info.empty()) {
71 return std::unique_ptr<AEAD_Mode>();
72 }
73
74 std::ostringstream mode_name;
75
76 mode_name << mode_info[0] << '(' << cipher_name;
77 for(size_t i = 1; i < mode_info.size(); ++i) {
78 mode_name << ',' << mode_info[i];
79 }
80 for(size_t i = 2; i < algo_parts.size(); ++i) {
81 mode_name << ',' << algo_parts[i];
82 }
83 mode_name << ')';
84
85 return AEAD_Mode::create(mode_name.str(), dir);
86 }
87
88#if defined(BOTAN_HAS_BLOCK_CIPHER)
89
90 SCAN_Name req(algo);
91
92 if(req.arg_count() == 0) {
93 return std::unique_ptr<AEAD_Mode>();
94 }
95
96 auto bc = BlockCipher::create(req.arg(0), provider);
97
98 if(!bc) {
99 return std::unique_ptr<AEAD_Mode>();
100 }
101
102 #if defined(BOTAN_HAS_AEAD_CCM)
103 if(req.algo_name() == "CCM") {
104 size_t tag_len = req.arg_as_integer(1, 16);
105 size_t L_len = req.arg_as_integer(2, 3);
106 if(dir == Cipher_Dir::Encryption) {
107 return std::make_unique<CCM_Encryption>(std::move(bc), tag_len, L_len);
108 } else {
109 return std::make_unique<CCM_Decryption>(std::move(bc), tag_len, L_len);
110 }
111 }
112 #endif
113
114 #if defined(BOTAN_HAS_AEAD_GCM)
115 if(req.algo_name() == "GCM") {
116 size_t tag_len = req.arg_as_integer(1, 16);
117 if(dir == Cipher_Dir::Encryption) {
118 return std::make_unique<GCM_Encryption>(std::move(bc), tag_len);
119 } else {
120 return std::make_unique<GCM_Decryption>(std::move(bc), tag_len);
121 }
122 }
123 #endif
124
125 #if defined(BOTAN_HAS_AEAD_OCB)
126 if(req.algo_name() == "OCB") {
127 size_t tag_len = req.arg_as_integer(1, 16);
128 if(dir == Cipher_Dir::Encryption) {
129 return std::make_unique<OCB_Encryption>(std::move(bc), tag_len);
130 } else {
131 return std::make_unique<OCB_Decryption>(std::move(bc), tag_len);
132 }
133 }
134 #endif
135
136 #if defined(BOTAN_HAS_AEAD_EAX)
137 if(req.algo_name() == "EAX") {
138 size_t tag_len = req.arg_as_integer(1, bc->block_size());
139 if(dir == Cipher_Dir::Encryption) {
140 return std::make_unique<EAX_Encryption>(std::move(bc), tag_len);
141 } else {
142 return std::make_unique<EAX_Decryption>(std::move(bc), tag_len);
143 }
144 }
145 #endif
146
147 #if defined(BOTAN_HAS_AEAD_SIV)
148 if(req.algo_name() == "SIV") {
149 if(dir == Cipher_Dir::Encryption) {
150 return std::make_unique<SIV_Encryption>(std::move(bc));
151 } else {
152 return std::make_unique<SIV_Decryption>(std::move(bc));
153 }
154 }
155 #endif
156
157#endif
158
159 return std::unique_ptr<AEAD_Mode>();
160}
#define BOTAN_UNUSED
Definition assert.h:118
static std::unique_ptr< AEAD_Mode > create(std::string_view algo, Cipher_Dir direction, std::string_view provider="")
Definition aead.cpp:53
static std::unique_ptr< BlockCipher > create(std::string_view algo_spec, std::string_view provider="")
virtual std::string provider() const
std::vector< std::string > split_on(std::string_view str, char delim)
Definition parsing.cpp:111
std::vector< std::string > parse_algorithm_name(std::string_view namex)
Definition parsing.cpp:57

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

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

◆ create_or_throw()

std::unique_ptr< AEAD_Mode > Botan::AEAD_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 43 of file aead.cpp.

45 {
46 if(auto aead = AEAD_Mode::create(algo, dir, provider)) {
47 return aead;
48 }
49
50 throw Lookup_Error("AEAD", algo, provider);
51}

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

Referenced by Botan::TLS::Cipher_State::advance_with_server_hello(), Botan::TLS::Connection_Cipher_State::Connection_Cipher_State(), Botan::TLS::Session::decrypt(), and Botan::TLS::Session::encrypt().

◆ 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::CCM_Mode, and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode.

Definition at line 130 of file aead.h.

130{ return 12; }

◆ 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 146 of file cipher_mode.h.

146{ finish_msg(final_block, offset); }
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 159 of file cipher_mode.h.

159 {
160 Botan::secure_vector<uint8_t> tmp(final_block.begin(), final_block.end());
161 finish_msg(tmp, offset);
162 final_block.resize(tmp.size());
163 std::copy(tmp.begin(), tmp.end(), final_block.begin());
164 }
std::vector< T, secure_allocator< T > > secure_vector
Definition secmem.h:61

◆ 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::OCB_Mode::has_keying_material ( ) const
finaloverridevirtual
Returns
true if a key has been set on this object

Implements Botan::SymmetricAlgorithm.

Definition at line 223 of file ocb.cpp.

223 {
224 return m_cipher->has_keying_material();
225}

References m_cipher.

◆ ideal_granularity()

size_t Botan::OCB_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 215 of file ocb.cpp.

215 {
216 return (m_par_blocks * block_size());
217}

References block_size().

◆ key_spec()

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

Implements Botan::SymmetricAlgorithm.

Definition at line 219 of file ocb.cpp.

219 {
220 return m_cipher->key_spec();
221}

References m_cipher.

◆ maximum_associated_data_inputs()

virtual size_t Botan::AEAD_Mode::maximum_associated_data_inputs ( ) const
inlinevirtualinherited

Returns the maximum supported number of associated data inputs which can be provided to set_associated_data_n

If returns 0, then no associated data is supported.

Reimplemented in Botan::SIV_Mode.

Definition at line 91 of file aead.h.

91{ return 1; }

◆ maximum_keylength()

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

Definition at line 95 of file sym_algo.h.

95{ return key_spec().maximum_keylength(); }
size_t maximum_keylength() const
Definition sym_algo.h:54
virtual Key_Length_Specification key_spec() const =0

◆ minimum_final_size()

◆ minimum_keylength()

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

Definition at line 100 of file sym_algo.h.

100{ return key_spec().minimum_keylength(); }
size_t minimum_keylength() const
Definition sym_algo.h:49

◆ name()

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

Implements Botan::SymmetricAlgorithm.

Definition at line 207 of file ocb.cpp.

207 {
208 return m_cipher->name() + "/OCB"; // include tag size?
209}

References m_cipher.

◆ output_length()

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

◆ par_blocks()

size_t Botan::OCB_Mode::par_blocks ( ) const
inlineprotected

Definition at line 64 of file ocb.h.

64{ return m_par_blocks; }

◆ par_bytes()

size_t Botan::OCB_Mode::par_bytes ( ) const
inlineprotected

Definition at line 66 of file ocb.h.

66{ return m_checksum.size(); }

◆ 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 123 of file cipher_mode.h.

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

Referenced by botan_cipher_update().

◆ process() [2/2]

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

Definition at line 125 of file cipher_mode.h.

125{ 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 234 of file cipher_mode.h.

234{ 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 164 of file cipher_mode.cpp.

164 {
165 const std::vector<std::string>& possible = {"base", "commoncrypto"};
166 std::vector<std::string> providers;
167 for(auto&& prov : possible) {
168 auto mode = Cipher_Mode::create(algo_spec, Cipher_Dir::Encryption, prov);
169 if(mode) {
170 providers.push_back(prov); // available
171 }
172 }
173 return providers;
174}
static std::unique_ptr< Cipher_Mode > create(std::string_view algo, Cipher_Dir direction, std::string_view provider="")
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 196 of file cipher_mode.h.

196{ return false; }

Referenced by botan_cipher_update().

◆ reset()

void Botan::OCB_Mode::reset ( )
finaloverridevirtual

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

Implements Botan::Cipher_Mode.

Definition at line 188 of file ocb.cpp.

188 {
189 m_block_index = 0;
192 m_last_nonce.clear();
193 m_stretch.clear();
194}
size_t m_block_index
Definition ocb.h:72
void zeroise(std::vector< T, Alloc > &vec)
Definition secmem.h:108

References m_ad_hash, m_block_index, m_checksum, and Botan::zeroise().

Referenced by clear().

◆ set_ad()

void Botan::AEAD_Mode::set_ad ( std::span< const uint8_t > 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 124 of file aead.h.

124{ set_associated_data(ad); }
void set_associated_data(std::span< const uint8_t > ad)
Definition aead.h:59

◆ set_associated_data() [1/2]

void Botan::AEAD_Mode::set_associated_data ( const uint8_t ad[],
size_t ad_len )
inlineinherited

Definition at line 61 of file aead.h.

61{ set_associated_data(std::span(ad, ad_len)); }

References Botan::AEAD_Mode::set_associated_data().

Referenced by Botan::AEAD_Mode::set_associated_data().

◆ set_associated_data() [2/2]

void Botan::AEAD_Mode::set_associated_data ( std::span< const uint8_t > 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.

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

Definition at line 59 of file aead.h.

59{ set_associated_data_n(0, ad); }
virtual void set_associated_data_n(size_t idx, std::span< const uint8_t > ad)=0

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

◆ set_associated_data_n()

void Botan::OCB_Mode::set_associated_data_n ( size_t idx,
std::span< const uint8_t > ad )
finaloverridevirtual

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.

Some AEADs (namely SIV) support multiple AD inputs. For all other modes only nominal AD input 0 is supported; all other values of idx will cause an exception.

Derived AEADs must implement this. For AEADs where maximum_associated_data_inputs() returns 1 (the default), the idx must simply be ignored.

Parameters
idxwhich associated data to set
adthe associated data

Implements Botan::AEAD_Mode.

Definition at line 232 of file ocb.cpp.

232 {
233 BOTAN_ARG_CHECK(idx == 0, "OCB: cannot handle non-zero index in set_associated_data_n");
235 m_ad_hash = ocb_hash(*m_L, *m_cipher, ad.data(), ad.size());
236}

References Botan::SymmetricAlgorithm::assert_key_material_set(), BOTAN_ARG_CHECK, m_ad_hash, m_cipher, and m_L.

◆ 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 111 of file aead.h.

111 {
113 }

◆ set_key() [1/3]

◆ set_key() [2/3]

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 126 of file sym_algo.h.

126{ set_key(std::span{key, length}); }

References Botan::SymmetricAlgorithm::set_key().

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

◆ set_key() [3/3]

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

Set the symmetric key of this object.

Parameters
keythe contiguous byte range to be set.

Definition at line 17 of file sym_algo.cpp.

17 {
18 if(!valid_keylength(key.size())) {
19 throw Invalid_Key_Length(name(), key.size());
20 }
21 key_schedule(key);
22}
bool valid_keylength(size_t length) const
Definition sym_algo.h:107
virtual std::string name() const =0

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

◆ 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 108 of file cipher_mode.h.

108{ return start_msg(nullptr, 0); }
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 96 of file cipher_mode.h.

96{ start_msg(nonce, nonce_len); }

◆ 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 89 of file cipher_mode.h.

89{ start_msg(nonce.data(), nonce.size()); }

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

◆ tag_size()

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

Reimplemented from Botan::Cipher_Mode.

Definition at line 45 of file ocb.h.

45{ return m_tag_size; }

◆ 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 133 of file cipher_mode.h.

133 {
134 BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
135 const size_t written = process(std::span(buffer).subspan(offset));
136 buffer.resize(offset + written);
137 }
#define BOTAN_ASSERT(expr, assertion_made)
Definition assert.h:50
size_t process(std::span< uint8_t > msg)

References BOTAN_ASSERT.

◆ update_granularity()

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

Implements Botan::Cipher_Mode.

Definition at line 211 of file ocb.cpp.

211 {
212 return block_size();
213}

References 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 107 of file sym_algo.h.

107{ return key_spec().valid_keylength(length); }
bool valid_keylength(size_t length) const
Definition sym_algo.h:42

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

◆ valid_nonce_length()

bool Botan::OCB_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 196 of file ocb.cpp.

196 {
197 if(length == 0) {
198 return false;
199 }
200 if(block_size() == 16) {
201 return length < 16;
202 } else {
203 return length < (block_size() - 1);
204 }
205}

References block_size().

Member Data Documentation

◆ m_ad_hash

secure_vector<uint8_t> Botan::OCB_Mode::m_ad_hash
protected

Definition at line 75 of file ocb.h.

Referenced by reset(), and set_associated_data_n().

◆ m_block_index

size_t Botan::OCB_Mode::m_block_index = 0
protected

Definition at line 72 of file ocb.h.

Referenced by reset().

◆ m_checksum

secure_vector<uint8_t> Botan::OCB_Mode::m_checksum
protected

Definition at line 74 of file ocb.h.

Referenced by reset().

◆ m_cipher

std::unique_ptr<BlockCipher> Botan::OCB_Mode::m_cipher
protected

Definition at line 69 of file ocb.h.

Referenced by clear(), has_keying_material(), key_spec(), name(), and set_associated_data_n().

◆ m_L

std::unique_ptr<L_computer> Botan::OCB_Mode::m_L
protected

Definition at line 70 of file ocb.h.

Referenced by clear(), and set_associated_data_n().


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