Botan 3.1.1
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | List of all members
Botan::KDF2 Class Referencefinal

#include <kdf2.h>

Inheritance diagram for Botan::KDF2:
Botan::KDF

Public Member Functions

KDF * clone () const
 
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T derive_key (size_t key_len, const uint8_t secret[], size_t secret_len, const uint8_t salt[], size_t salt_len, const uint8_t label[]=nullptr, size_t label_len=0) const
 
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T derive_key (size_t key_len, const uint8_t secret[], size_t secret_len, std::string_view salt="", std::string_view label="") const
 
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T derive_key (size_t key_len, std::span< const uint8_t > secret, const uint8_t salt[], size_t salt_len, std::string_view label="") const
 
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T derive_key (size_t key_len, std::span< const uint8_t > secret, std::span< const uint8_t > salt, std::span< const uint8_t > label) const
 
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T derive_key (size_t key_len, std::span< const uint8_t > secret, std::string_view salt="", std::string_view label="") const
 
void kdf (uint8_t key[], size_t key_len, const uint8_t secret[], size_t secret_len, const uint8_t salt[], size_t salt_len, const uint8_t label[], size_t label_len) const override
 
 KDF2 (std::unique_ptr< HashFunction > hash)
 
std::string name () const override
 
std::unique_ptr< KDF > new_object () const override
 

Static Public Member Functions

static std::unique_ptr< KDF > create (std::string_view algo_spec, std::string_view provider="")
 
static std::unique_ptr< KDF > create_or_throw (std::string_view algo_spec, std::string_view provider="")
 
static std::vector< std::string > providers (std::string_view algo_spec)
 

Detailed Description

KDF2, from IEEE 1363

Definition at line 19 of file kdf2.h.

Constructor & Destructor Documentation

◆ KDF2()

Botan::KDF2::KDF2 ( std::unique_ptr< HashFunction >  hash)
inlineexplicit
Parameters
hashthe hash function to use

Definition at line 37 of file kdf2.h.

37: m_hash(std::move(hash)) {}

Member Function Documentation

◆ clone()

KDF * Botan::KDF::clone ( ) const
inlineinherited
Returns
new object representing the same algorithm as *this

Definition at line 187 of file kdf.h.

187{ return this->new_object().release(); }
Botan::KDF::new_object
virtual std::unique_ptr< KDF > new_object() const =0

◆ create()

std::unique_ptr< KDF > Botan::KDF::create ( std::string_view  algo_spec,
std::string_view  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 choose
Returns
a null pointer if the algo/provider combination cannot be found

Definition at line 71 of file kdf.cpp.

71 {
72 const SCAN_Name req(algo_spec);
73
74#if defined(BOTAN_HAS_HKDF)
75 if(req.algo_name() == "HKDF" && req.arg_count() == 1) {
76 if(provider.empty() || provider == "base") {
77 return kdf_create_mac_or_hash<HKDF>(req.arg(0));
78 }
79 }
80
81 if(req.algo_name() == "HKDF-Extract" && req.arg_count() == 1) {
82 if(provider.empty() || provider == "base") {
83 return kdf_create_mac_or_hash<HKDF_Extract>(req.arg(0));
84 }
85 }
86
87 if(req.algo_name() == "HKDF-Expand" && req.arg_count() == 1) {
88 if(provider.empty() || provider == "base") {
89 return kdf_create_mac_or_hash<HKDF_Expand>(req.arg(0));
90 }
91 }
92#endif
93
94#if defined(BOTAN_HAS_KDF2)
95 if(req.algo_name() == "KDF2" && req.arg_count() == 1) {
96 if(provider.empty() || provider == "base") {
97 if(auto hash = HashFunction::create(req.arg(0))) {
98 return std::make_unique<KDF2>(std::move(hash));
99 }
100 }
101 }
102#endif
103
104#if defined(BOTAN_HAS_KDF1_18033)
105 if(req.algo_name() == "KDF1-18033" && req.arg_count() == 1) {
106 if(provider.empty() || provider == "base") {
107 if(auto hash = HashFunction::create(req.arg(0))) {
108 return std::make_unique<KDF1_18033>(std::move(hash));
109 }
110 }
111 }
112#endif
113
114#if defined(BOTAN_HAS_KDF1)
115 if(req.algo_name() == "KDF1" && req.arg_count() == 1) {
116 if(provider.empty() || provider == "base") {
117 if(auto hash = HashFunction::create(req.arg(0))) {
118 return std::make_unique<KDF1>(std::move(hash));
119 }
120 }
121 }
122#endif
123
124#if defined(BOTAN_HAS_TLS_V12_PRF)
125 if(req.algo_name() == "TLS-12-PRF" && req.arg_count() == 1) {
126 if(provider.empty() || provider == "base") {
127 return kdf_create_mac_or_hash<TLS_12_PRF>(req.arg(0));
128 }
129 }
130#endif
131
132#if defined(BOTAN_HAS_X942_PRF)
133 if(req.algo_name() == "X9.42-PRF" && req.arg_count() == 1) {
134 if(provider.empty() || provider == "base") {
135 return std::make_unique<X942_PRF>(req.arg(0));
136 }
137 }
138#endif
139
140#if defined(BOTAN_HAS_SP800_108)
141 if(req.algo_name() == "SP800-108-Counter" && req.arg_count() == 1) {
142 if(provider.empty() || provider == "base") {
143 return kdf_create_mac_or_hash<SP800_108_Counter>(req.arg(0));
144 }
145 }
146
147 if(req.algo_name() == "SP800-108-Feedback" && req.arg_count() == 1) {
148 if(provider.empty() || provider == "base") {
149 return kdf_create_mac_or_hash<SP800_108_Feedback>(req.arg(0));
150 }
151 }
152
153 if(req.algo_name() == "SP800-108-Pipeline" && req.arg_count() == 1) {
154 if(provider.empty() || provider == "base") {
155 return kdf_create_mac_or_hash<SP800_108_Pipeline>(req.arg(0));
156 }
157 }
158#endif
159
160#if defined(BOTAN_HAS_SP800_56A)
161 if(req.algo_name() == "SP800-56A" && req.arg_count() == 1) {
162 if(auto hash = HashFunction::create(req.arg(0))) {
163 return std::make_unique<SP800_56A_Hash>(std::move(hash));
164 }
165 if(auto mac = MessageAuthenticationCode::create(req.arg(0))) {
166 return std::make_unique<SP800_56A_HMAC>(std::move(mac));
167 }
168 }
169#endif
170
171#if defined(BOTAN_HAS_SP800_56C)
172 if(req.algo_name() == "SP800-56C" && req.arg_count() == 1) {
173 std::unique_ptr<KDF> exp(kdf_create_mac_or_hash<SP800_108_Feedback>(req.arg(0)));
174 if(exp) {
175 if(auto mac = MessageAuthenticationCode::create(req.arg(0))) {
176 return std::make_unique<SP800_56C>(std::move(mac), std::move(exp));
177 }
178
179 if(auto mac = MessageAuthenticationCode::create(fmt("HMAC({})", req.arg(0)))) {
180 return std::make_unique<SP800_56C>(std::move(mac), std::move(exp));
181 }
182 }
183 }
184#endif
185
186 BOTAN_UNUSED(req);
187 BOTAN_UNUSED(provider);
188
189 return nullptr;
190}
BOTAN_UNUSED
#define BOTAN_UNUSED
Definition: assert.h:118
Botan::HashFunction::create
static std::unique_ptr< HashFunction > create(std::string_view algo_spec, std::string_view provider="")
Definition: hash.cpp:103
Botan::MessageAuthenticationCode::create
static std::unique_ptr< MessageAuthenticationCode > create(std::string_view algo_spec, std::string_view provider="")
Definition: mac.cpp:46
Botan::fmt
std::string fmt(std::string_view format, const T &... args)
Definition: fmt.h:53

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_count(), BOTAN_UNUSED, Botan::HashFunction::create(), Botan::MessageAuthenticationCode::create(), and Botan::fmt().

Referenced by Botan::KDF::create_or_throw(), and Botan::get_kdf().

◆ create_or_throw()

std::unique_ptr< KDF > Botan::KDF::create_or_throw ( std::string_view  algo_spec,
std::string_view  provider = "" 
)
staticinherited

Create an instance based on a name, or throw if the algo/provider combination cannot be found. If provider is empty then best available is chosen.

Definition at line 193 of file kdf.cpp.

193 {
194 if(auto kdf = KDF::create(algo, provider)) {
195 return kdf;
196 }
197 throw Lookup_Error("KDF", algo, provider);
198}
Botan::KDF::create
static std::unique_ptr< KDF > create(std::string_view algo_spec, std::string_view provider="")
Definition: kdf.cpp:71
Botan::KDF::kdf
virtual void kdf(uint8_t key[], size_t key_len, const uint8_t secret[], size_t secret_len, const uint8_t salt[], size_t salt_len, const uint8_t label[], size_t label_len) const =0

References Botan::KDF::create(), and Botan::KDF::kdf().

Referenced by botan_kdf(), Botan::ECIES_KA_Operation::derive_secret(), Botan::PK_Ops::KEM_Decryption_with_KDF::KEM_Decryption_with_KDF(), Botan::PK_Ops::KEM_Encryption_with_KDF::KEM_Encryption_with_KDF(), Botan::PK_Ops::Key_Agreement_with_KDF::Key_Agreement_with_KDF(), and Botan::TLS::Handshake_State::protocol_specific_prf().

◆ derive_key() [1/5]

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T Botan::KDF::derive_key ( size_t  key_len,
const uint8_t  secret[],
size_t  secret_len,
const uint8_t  salt[],
size_t  salt_len,
const uint8_t  label[] = nullptr,
size_t  label_len = 0 
) const
inlineinherited

Derive a key

Parameters
key_lenthe desired output length in bytes
secretthe secret input
secret_lensize of secret in bytes
salta diversifier
salt_lensize of salt in bytes
labelpurpose for the derived keying material
label_lensize of label in bytes
Returns
the derived key

Definition at line 85 of file kdf.h.

91 {
92 T key(key_len);
93 kdf(key.data(), key.size(), secret, secret_len, salt, salt_len, label, label_len);
94 return key;
95 }
T
FE_25519 T
Definition: ge.cpp:34

References T.

◆ derive_key() [2/5]

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T Botan::KDF::derive_key ( size_t  key_len,
const uint8_t  secret[],
size_t  secret_len,
std::string_view  salt = "",
std::string_view  label = "" 
) const
inlineinherited

Derive a key

Parameters
key_lenthe desired output length in bytes
secretthe secret input
secret_lensize of secret in bytes
salta diversifier
labelpurpose for the derived keying material
Returns
the derived key

Definition at line 165 of file kdf.h.

169 {
170 return derive_key<T>(key_len,
171 secret,
172 secret_len,
173 cast_char_ptr_to_uint8(salt.data()),
174 salt.length(),
175 cast_char_ptr_to_uint8(label.data()),
176 label.length());
177 }
Botan::cast_char_ptr_to_uint8
const uint8_t * cast_char_ptr_to_uint8(const char *s)
Definition: mem_ops.h:177

References Botan::cast_char_ptr_to_uint8().

◆ derive_key() [3/5]

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T Botan::KDF::derive_key ( size_t  key_len,
std::span< const uint8_t >  secret,
const uint8_t  salt[],
size_t  salt_len,
std::string_view  label = "" 
) const
inlineinherited

Derive a key

Parameters
key_lenthe desired output length in bytes
secretthe secret input
salta diversifier
salt_lensize of salt in bytes
labelpurpose for the derived keying material
Returns
the derived key

Definition at line 146 of file kdf.h.

150 {
151 return derive_key<T>(
152 key_len, secret.data(), secret.size(), salt, salt_len, cast_char_ptr_to_uint8(label.data()), label.size());
153 }

References Botan::cast_char_ptr_to_uint8().

◆ derive_key() [4/5]

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T Botan::KDF::derive_key ( size_t  key_len,
std::span< const uint8_t >  secret,
std::span< const uint8_t >  salt,
std::span< const uint8_t >  label 
) const
inlineinherited

Derive a key

Parameters
key_lenthe desired output length in bytes
secretthe secret input
salta diversifier
labelpurpose for the derived keying material
Returns
the derived key

Definition at line 128 of file kdf.h.

131 {
132 return derive_key<T>(
133 key_len, secret.data(), secret.size(), salt.data(), salt.size(), label.data(), label.size());
134 }

◆ derive_key() [5/5]

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T Botan::KDF::derive_key ( size_t  key_len,
std::span< const uint8_t >  secret,
std::string_view  salt = "",
std::string_view  label = "" 
) const
inlineinherited

Derive a key

Parameters
key_lenthe desired output length in bytes
secretthe secret input
salta diversifier
labelpurpose for the derived keying material
Returns
the derived key

Definition at line 106 of file kdf.h.

109 {
110 return derive_key<T>(key_len,
111 secret.data(),
112 secret.size(),
113 cast_char_ptr_to_uint8(salt.data()),
114 salt.length(),
115 cast_char_ptr_to_uint8(label.data()),
116 label.length());
117 }

References Botan::cast_char_ptr_to_uint8().

◆ kdf()

void Botan::KDF2::kdf ( uint8_t  key[],
size_t  key_len,
const uint8_t  secret[],
size_t  secret_len,
const uint8_t  salt[],
size_t  salt_len,
const uint8_t  label[],
size_t  label_len 
) const
overridevirtual

Derive a key

Parameters
keybuffer holding the derived key, must be of length key_len
key_lenthe desired output length in bytes
secretthe secret input
secret_lensize of secret in bytes
salta diversifier
salt_lensize of salt in bytes
labelpurpose for the derived keying material
label_lensize of label in bytes

Implements Botan::KDF.

Definition at line 23 of file kdf2.cpp.

30 {
31 if(key_len == 0) {
32 return;
33 }
34
35 const size_t blocks_required = key_len / m_hash->output_length();
36
37 if(blocks_required >= 0xFFFFFFFE) {
38 throw Invalid_Argument("KDF2 maximum output length exceeeded");
39 }
40
41 uint32_t counter = 1;
42 secure_vector<uint8_t> h;
43
44 size_t offset = 0;
45 while(offset != key_len) {
46 m_hash->update(secret, secret_len);
47 m_hash->update_be(counter);
48 m_hash->update(label, label_len);
49 m_hash->update(salt, salt_len);
50 m_hash->final(h);
51
52 const size_t added = std::min(h.size(), key_len - offset);
53 copy_mem(&key[offset], h.data(), added);
54 offset += added;
55
56 counter += 1;
57 BOTAN_ASSERT_NOMSG(counter != 0); // no overflow
58 }
59}
BOTAN_ASSERT_NOMSG
#define BOTAN_ASSERT_NOMSG(expr)
Definition: assert.h:59
Botan::copy_mem
constexpr void copy_mem(T *out, const T *in, size_t n)
Definition: mem_ops.h:120

References BOTAN_ASSERT_NOMSG, and Botan::copy_mem().

◆ name()

std::string Botan::KDF2::name ( ) const
overridevirtual
Returns
KDF name

Implements Botan::KDF.

Definition at line 15 of file kdf2.cpp.

15 {
16 return fmt("KDF2({})", m_hash->name());
17}

References Botan::fmt().

◆ new_object()

std::unique_ptr< KDF > Botan::KDF2::new_object ( ) const
overridevirtual
Returns
new object representing the same algorithm as *this

Implements Botan::KDF.

Definition at line 19 of file kdf2.cpp.

19 {
20 return std::make_unique<KDF2>(m_hash->new_object());
21}

◆ providers()

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

Definition at line 200 of file kdf.cpp.

200 {
201 return probe_providers_of<KDF>(algo_spec);
202}
The documentation for this class was generated from the following files:
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