Botan 2.19.2
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | Static Protected Attributes | List of all members
Botan::GCM_Decryption Class Referencefinal

#include <gcm.h>

Inheritance diagram for Botan::GCM_Decryption:
Botan::GCM_Mode Botan::AEAD_Mode Botan::Cipher_Mode Botan::SymmetricAlgorithm

Public Member Functions

virtual bool associated_data_requires_key () const
 
bool authenticated () const override
 
void clear () override
 
size_t default_nonce_length () const override
 
void finish (secure_vector< uint8_t > &final_block, size_t offset=0) override
 
 GCM_Decryption (BlockCipher *cipher, size_t tag_size=16)
 
Key_Length_Specification key_spec () const override
 
virtual size_t maximum_associated_data_inputs () const
 
size_t maximum_keylength () const
 
size_t minimum_final_size () const override
 
size_t minimum_keylength () const
 
std::string name () const override
 
size_t output_length (size_t input_length) const override
 
size_t process (uint8_t buf[], size_t size) override
 
std::string provider () const override
 
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
 
virtual void set_associated_data_n (size_t i, const uint8_t ad[], size_t ad_len)
 
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)
 
void start ()
 
template<typename Alloc >
void start (const std::vector< uint8_t, Alloc > &nonce)
 
void start (const uint8_t nonce[], size_t nonce_len)
 
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 len) const override
 

Static Public Member Functions

static std::unique_ptr< AEAD_Modecreate (const std::string &algo, Cipher_Dir direction, const std::string &provider="")
 
static std::unique_ptr< AEAD_Modecreate_or_throw (const std::string &algo, Cipher_Dir direction, 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
 

Protected Attributes

const std::string m_cipher_name
 
std::unique_ptr< StreamCipherm_ctr
 
std::unique_ptr< GHASHm_ghash
 
const size_t m_tag_size
 

Static Protected Attributes

static const size_t GCM_BS = 16
 

Detailed Description

GCM Decryption

Definition at line 92 of file gcm.h.

Constructor & Destructor Documentation

◆ GCM_Decryption()

Botan::GCM_Decryption::GCM_Decryption ( BlockCipher cipher,
size_t  tag_size = 16 
)
inline
Parameters
cipherthe 128 bit block cipher to use
tag_sizeis how big the auth tag will be

Definition at line 99 of file gcm.h.

99 :
100 GCM_Mode(cipher, tag_size) {}
GCM_Mode(BlockCipher *cipher, size_t tag_size)
Definition: gcm.cpp:19
size_t tag_size() const override
Definition: gcm.h:39

Member Function Documentation

◆ 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 94 of file aead.h.

94{ return true; }

◆ 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 47 of file aead.h.

47{ return true; }

◆ clear()

void Botan::GCM_Mode::clear ( )
overridevirtualinherited

Reset the state.

Implements Botan::SymmetricAlgorithm.

Definition at line 36 of file gcm.cpp.

37 {
38 m_ctr->clear();
39 m_ghash->clear();
40 reset();
41 }
std::unique_ptr< GHASH > m_ghash
Definition: gcm.h:57
void reset() override
Definition: gcm.cpp:43
std::unique_ptr< StreamCipher > m_ctr
Definition: gcm.h:56

References Botan::GCM_Mode::m_ctr, Botan::GCM_Mode::m_ghash, and Botan::GCM_Mode::reset().

◆ create()

std::unique_ptr< AEAD_Mode > Botan::AEAD_Mode::create ( const std::string &  algo,
Cipher_Dir  direction,
const std::string &  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 60 of file aead.cpp.

63 {
65#if defined(BOTAN_HAS_AEAD_CHACHA20_POLY1305)
66 if(algo == "ChaCha20Poly1305")
67 {
68 if(dir == ENCRYPTION)
69 return std::unique_ptr<AEAD_Mode>(new ChaCha20Poly1305_Encryption);
70 else
71 return std::unique_ptr<AEAD_Mode>(new ChaCha20Poly1305_Decryption);
72
73 }
74#endif
75
76 if(algo.find('/') != std::string::npos)
77 {
78 const std::vector<std::string> algo_parts = split_on(algo, '/');
79 const std::string cipher_name = algo_parts[0];
80 const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
81
82 if(mode_info.empty())
83 return std::unique_ptr<AEAD_Mode>();
84
85 std::ostringstream alg_args;
86
87 alg_args << '(' << cipher_name;
88 for(size_t i = 1; i < mode_info.size(); ++i)
89 alg_args << ',' << mode_info[i];
90 for(size_t i = 2; i < algo_parts.size(); ++i)
91 alg_args << ',' << algo_parts[i];
92 alg_args << ')';
93
94 const std::string mode_name = mode_info[0] + alg_args.str();
95 return AEAD_Mode::create(mode_name, dir);
96 }
97
98#if defined(BOTAN_HAS_BLOCK_CIPHER)
99
100 SCAN_Name req(algo);
101
102 if(req.arg_count() == 0)
103 {
104 return std::unique_ptr<AEAD_Mode>();
105 }
106
107 std::unique_ptr<BlockCipher> bc(BlockCipher::create(req.arg(0), provider));
108
109 if(!bc)
110 {
111 return std::unique_ptr<AEAD_Mode>();
112 }
113
114#if defined(BOTAN_HAS_AEAD_CCM)
115 if(req.algo_name() == "CCM")
116 {
117 size_t tag_len = req.arg_as_integer(1, 16);
118 size_t L_len = req.arg_as_integer(2, 3);
119 if(dir == ENCRYPTION)
120 return std::unique_ptr<AEAD_Mode>(new CCM_Encryption(bc.release(), tag_len, L_len));
121 else
122 return std::unique_ptr<AEAD_Mode>(new CCM_Decryption(bc.release(), tag_len, L_len));
123 }
124#endif
125
126#if defined(BOTAN_HAS_AEAD_GCM)
127 if(req.algo_name() == "GCM")
128 {
129 size_t tag_len = req.arg_as_integer(1, 16);
130 if(dir == ENCRYPTION)
131 return std::unique_ptr<AEAD_Mode>(new GCM_Encryption(bc.release(), tag_len));
132 else
133 return std::unique_ptr<AEAD_Mode>(new GCM_Decryption(bc.release(), tag_len));
134 }
135#endif
136
137#if defined(BOTAN_HAS_AEAD_OCB)
138 if(req.algo_name() == "OCB")
139 {
140 size_t tag_len = req.arg_as_integer(1, 16);
141 if(dir == ENCRYPTION)
142 return std::unique_ptr<AEAD_Mode>(new OCB_Encryption(bc.release(), tag_len));
143 else
144 return std::unique_ptr<AEAD_Mode>(new OCB_Decryption(bc.release(), tag_len));
145 }
146#endif
147
148#if defined(BOTAN_HAS_AEAD_EAX)
149 if(req.algo_name() == "EAX")
150 {
151 size_t tag_len = req.arg_as_integer(1, bc->block_size());
152 if(dir == ENCRYPTION)
153 return std::unique_ptr<AEAD_Mode>(new EAX_Encryption(bc.release(), tag_len));
154 else
155 return std::unique_ptr<AEAD_Mode>(new EAX_Decryption(bc.release(), tag_len));
156 }
157#endif
158
159#if defined(BOTAN_HAS_AEAD_SIV)
160 if(req.algo_name() == "SIV")
161 {
162 if(dir == ENCRYPTION)
163 return std::unique_ptr<AEAD_Mode>(new SIV_Encryption(bc.release()));
164 else
165 return std::unique_ptr<AEAD_Mode>(new SIV_Decryption(bc.release()));
166 }
167#endif
168
169#endif
170
171 return std::unique_ptr<AEAD_Mode>();
172 }
#define BOTAN_UNUSED(...)
Definition: assert.h:142
static std::unique_ptr< AEAD_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: aead.cpp:60
static std::unique_ptr< BlockCipher > create(const std::string &algo_spec, const std::string &provider="")
virtual std::string provider() const
Definition: cipher_mode.h:180
std::vector< std::string > split_on(const std::string &str, char delim)
Definition: parsing.cpp:148
@ ENCRYPTION
Definition: cipher_mode.h:23
std::vector< std::string > parse_algorithm_name(const std::string &namex)
Definition: parsing.cpp:95

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 ( const std::string &  algo,
Cipher_Dir  direction,
const std::string &  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 50 of file aead.cpp.

53 {
54 if(auto aead = AEAD_Mode::create(algo, dir, provider))
55 return aead;
56
57 throw Lookup_Error("AEAD", algo, provider);
58 }

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

Referenced by Botan::TLS::Connection_Cipher_State::Connection_Cipher_State(), Botan::TLS::Session::decrypt(), Botan::TLS::Session::encrypt(), Botan::mceies_decrypt(), and Botan::mceies_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()

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

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

Implements Botan::Cipher_Mode.

Definition at line 150 of file gcm.cpp.

151 {
152 BOTAN_ARG_CHECK(offset <= buffer.size(), "Invalid offset");
153 const size_t sz = buffer.size() - offset;
154 uint8_t* buf = buffer.data() + offset;
155
156 if(sz < tag_size())
157 throw Decoding_Error("Insufficient input for GCM decryption, tag missing");
158
159 const size_t remaining = sz - tag_size();
160
161 // handle any final input before the tag
162 if(remaining)
163 {
164 m_ghash->update(buf, remaining);
165 m_ctr->cipher(buf, buf, remaining);
166 }
167
168 uint8_t mac[16] = { 0 };
169 m_ghash->final(mac, tag_size());
170
171 const uint8_t* included_tag = &buffer[remaining+offset];
172
173 if(!constant_time_compare(mac, included_tag, tag_size()))
174 throw Invalid_Authentication_Tag("GCM tag check failed");
175
176 buffer.resize(offset + remaining);
177 }
#define BOTAN_ARG_CHECK(expr, msg)
Definition: assert.h:37
bool constant_time_compare(const uint8_t x[], const uint8_t y[], size_t len)
Definition: mem_ops.h:82

References BOTAN_ARG_CHECK, Botan::constant_time_compare(), Botan::GCM_Mode::m_ctr, Botan::GCM_Mode::m_ghash, and Botan::GCM_Mode::tag_size().

◆ key_spec()

Key_Length_Specification Botan::GCM_Mode::key_spec ( ) const
overridevirtualinherited
Returns
object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 69 of file gcm.cpp.

70 {
71 return m_ctr->key_spec();
72 }

References Botan::GCM_Mode::m_ctr.

◆ 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 87 of file aead.h.

87{ return 1; }

◆ maximum_keylength()

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

Definition at line 120 of file sym_algo.h.

121 {
122 return key_spec().maximum_keylength();
123 }
size_t maximum_keylength() const
Definition: sym_algo.h:70
virtual Key_Length_Specification key_spec() const =0

◆ minimum_final_size()

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

Implements Botan::Cipher_Mode.

Definition at line 108 of file gcm.h.

108{ return tag_size(); }

References Botan::Cipher_Mode::tag_size().

◆ minimum_keylength()

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

Definition at line 128 of file sym_algo.h.

129 {
130 return key_spec().minimum_keylength();
131 }
size_t minimum_keylength() const
Definition: sym_algo.h:62

Referenced by botan_block_cipher_get_keyspec(), and botan_mac_get_keyspec().

◆ name()

std::string Botan::GCM_Mode::name ( ) const
overridevirtualinherited
Returns
the algorithm name

Implements Botan::SymmetricAlgorithm.

Definition at line 48 of file gcm.cpp.

49 {
50 return (m_cipher_name + "/GCM(" + std::to_string(tag_size()) + ")");
51 }
const std::string m_cipher_name
Definition: gcm.h:54
std::string to_string(const BER_Object &obj)
Definition: asn1_obj.cpp:213

References Botan::GCM_Mode::m_cipher_name, Botan::GCM_Mode::tag_size(), and Botan::ASN1::to_string().

Referenced by Botan::GCM_Mode::GCM_Mode().

◆ output_length()

size_t Botan::GCM_Decryption::output_length ( size_t  input_length) const
inlineoverridevirtual

Returns the size of the output if this transform is used to process a message with input_length bytes. In most cases the answer is precise. If it is not possible to precise (namely for CBC decryption) instead a lower bound is returned.

Implements Botan::Cipher_Mode.

Definition at line 102 of file gcm.h.

103 {
104 BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input");
105 return input_length - tag_size();
106 }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:55

References BOTAN_ASSERT, and Botan::Cipher_Mode::tag_size().

◆ process()

size_t Botan::GCM_Decryption::process ( uint8_t  msg[],
size_t  msg_len 
)
overridevirtual

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

Implements Botan::Cipher_Mode.

Definition at line 142 of file gcm.cpp.

143 {
144 BOTAN_ARG_CHECK(sz % update_granularity() == 0, "Invalid buffer size");
145 m_ghash->update(buf, sz);
146 m_ctr->cipher(buf, buf, sz);
147 return sz;
148 }
size_t update_granularity() const override
Definition: gcm.cpp:58

References BOTAN_ARG_CHECK, Botan::GCM_Mode::m_ctr, Botan::GCM_Mode::m_ghash, and Botan::GCM_Mode::update_granularity().

◆ provider()

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

Reimplemented from Botan::Cipher_Mode.

Definition at line 53 of file gcm.cpp.

54 {
55 return m_ghash->provider();
56 }

References Botan::GCM_Mode::m_ghash.

◆ 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 173 of file cipher_mode.cpp.

174 {
175 const std::vector<std::string>& possible = { "base", "openssl", "commoncrypto" };
176 std::vector<std::string> providers;
177 for(auto&& prov : possible)
178 {
179 std::unique_ptr<Cipher_Mode> mode = Cipher_Mode::create(algo_spec, ENCRYPTION, prov);
180 if(mode)
181 {
182 providers.push_back(prov); // available
183 }
184 }
185 return providers;
186 }
static std::vector< std::string > providers(const std::string &algo_spec)
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:50

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

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

◆ reset()

void Botan::GCM_Mode::reset ( )
overridevirtualinherited

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

Implements Botan::Cipher_Mode.

Definition at line 43 of file gcm.cpp.

44 {
45 m_ghash->reset();
46 }

References Botan::GCM_Mode::m_ghash.

Referenced by Botan::GCM_Mode::clear().

◆ 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 121 of file aead.h.

122 {
123 set_associated_data(ad.data(), ad.size());
124 }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0

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

◆ set_associated_data()

void Botan::GCM_Mode::set_associated_data ( const uint8_t  ad[],
size_t  ad_len 
)
overridevirtualinherited

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 86 of file gcm.cpp.

87 {
88 m_ghash->set_associated_data(ad, ad_len);
89 }

References Botan::GCM_Mode::m_ghash.

◆ set_associated_data_n()

void Botan::AEAD_Mode::set_associated_data_n ( size_t  i,
const uint8_t  ad[],
size_t  ad_len 
)
virtualinherited

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 i will cause an exception.

Parameters
adthe associated data
ad_lenlength of add in bytes

Reimplemented in Botan::SIV_Mode.

Definition at line 42 of file aead.cpp.

43 {
44 if(i == 0)
45 this->set_associated_data(ad, ad_len);
46 else
47 throw Invalid_Argument("AEAD '" + name() + "' does not support multiple associated data");
48 }
virtual std::string name() const =0

References Botan::SymmetricAlgorithm::name(), and Botan::AEAD_Mode::set_associated_data().

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

◆ 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 106 of file aead.h.

107 {
108 set_associated_data(ad.data(), ad.size());
109 }

◆ set_key() [1/3]

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

Definition at line 153 of file sym_algo.h.

154 {
155 set_key(key.data(), key.size());
156 }
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:147

◆ set_key() [2/3]

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

◆ set_key() [3/3]

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:138

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

◆ start() [1/3]

void Botan::Cipher_Mode::start ( )
inlineinherited

Begin processing a message.

Definition at line 87 of file cipher_mode.h.

88 {
89 return start_msg(nullptr, 0);
90 }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ start() [2/3]

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 69 of file cipher_mode.h.

70 {
71 start_msg(nonce.data(), nonce.size());
72 }

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

◆ start() [3/3]

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 79 of file cipher_mode.h.

80 {
81 start_msg(nonce, nonce_len);
82 }

◆ tag_size()

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

Reimplemented from Botan::Cipher_Mode.

Definition at line 39 of file gcm.h.

39{ return m_tag_size; }
const size_t m_tag_size
Definition: gcm.h:53

Referenced by Botan::GCM_Encryption::finish(), finish(), and Botan::GCM_Mode::name().

◆ 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 112 of file cipher_mode.h.

113 {
114 BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
115 uint8_t* buf = buffer.data() + offset;
116 const size_t buf_size = buffer.size() - offset;
117
118 const size_t written = process(buf, buf_size);
119 buffer.resize(offset + written);
120 }
virtual size_t process(uint8_t msg[], size_t msg_len)=0

References BOTAN_ASSERT.

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

◆ update_granularity()

size_t Botan::GCM_Mode::update_granularity ( ) const
overridevirtualinherited
Returns
size of required blocks to update

Implements Botan::Cipher_Mode.

Definition at line 58 of file gcm.cpp.

59 {
60 return GCM_BS * std::max<size_t>(2, BOTAN_BLOCK_CIPHER_PAR_MULT);
61 }
static const size_t GCM_BS
Definition: gcm.h:51

References Botan::GCM_Mode::GCM_BS.

Referenced by Botan::GCM_Encryption::process(), and process().

◆ 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 138 of file sym_algo.h.

139 {
140 return key_spec().valid_keylength(length);
141 }
bool valid_keylength(size_t length) const
Definition: sym_algo.h:52

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

◆ valid_nonce_length()

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

Implements Botan::Cipher_Mode.

Definition at line 63 of file gcm.cpp.

64 {
65 // GCM does not support empty nonces
66 return (len > 0);
67 }

◆ verify_key_set()

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

Definition at line 171 of file sym_algo.h.

172 {
173 if(cond == false)
174 throw_key_not_set_error();
175 }

Referenced by Botan::ChaCha::cipher(), Botan::CTR_BE::cipher(), Botan::RC4::cipher(), Botan::Salsa20::cipher(), Botan::SHAKE_128_Cipher::cipher(), 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::CAST_256::decrypt_n(), Botan::DES::decrypt_n(), Botan::TripleDES::decrypt_n(), Botan::DESX::decrypt_n(), Botan::GOST_28147_89::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::KASUMI::decrypt_n(), Botan::Lion::decrypt_n(), Botan::MISTY1::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::XTEA::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::CAST_256::encrypt_n(), Botan::DES::encrypt_n(), Botan::TripleDES::encrypt_n(), Botan::DESX::encrypt_n(), Botan::GOST_28147_89::encrypt_n(), Botan::IDEA::encrypt_n(), Botan::KASUMI::encrypt_n(), Botan::Lion::encrypt_n(), Botan::MISTY1::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::XTEA::encrypt_n(), Botan::OCB_Encryption::finish(), Botan::OCB_Decryption::finish(), Botan::GHASH::ghash_update(), Botan::CFB_Encryption::process(), Botan::CFB_Decryption::process(), Botan::ChaCha::seek(), Botan::CTR_BE::seek(), Botan::Salsa20::seek(), Botan::OCB_Mode::set_associated_data(), Botan::ChaCha::set_iv(), Botan::Salsa20::set_iv(), Botan::GHASH::update(), Botan::GHASH::update_associated_data(), and Botan::ChaCha::write_keystream().

Member Data Documentation

◆ GCM_BS

const size_t Botan::GCM_Mode::GCM_BS = 16
staticprotectedinherited

Definition at line 51 of file gcm.h.

Referenced by Botan::GCM_Mode::GCM_Mode(), and Botan::GCM_Mode::update_granularity().

◆ m_cipher_name

const std::string Botan::GCM_Mode::m_cipher_name
protectedinherited

Definition at line 54 of file gcm.h.

Referenced by Botan::GCM_Mode::name().

◆ m_ctr

std::unique_ptr<StreamCipher> Botan::GCM_Mode::m_ctr
protectedinherited

◆ m_ghash

std::unique_ptr<GHASH> Botan::GCM_Mode::m_ghash
protectedinherited

◆ m_tag_size

const size_t Botan::GCM_Mode::m_tag_size
protectedinherited

Definition at line 53 of file gcm.h.

Referenced by Botan::GCM_Mode::GCM_Mode().


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