Botan 3.2.0
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | List of all members
Botan::HKDF Class Referencefinal

#include <hkdf.h>

Inheritance diagram for Botan::HKDF:
Botan::KDF

Public Member Functions

KDFclone () 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 derive_key (std::span< uint8_t > key, std::span< const uint8_t > secret, std::span< const uint8_t > salt, std::span< const uint8_t > label) const
 
 HKDF (std::unique_ptr< MessageAuthenticationCode > prf)
 
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
 
std::string name () const override
 
std::unique_ptr< KDFnew_object () const override
 

Static Public Member Functions

static std::unique_ptr< KDFcreate (std::string_view algo_spec, std::string_view provider="")
 
static std::unique_ptr< KDFcreate_or_throw (std::string_view algo_spec, std::string_view provider="")
 
static std::vector< std::string > providers (std::string_view algo_spec)
 

Detailed Description

HKDF from RFC 5869.

Definition at line 20 of file hkdf.h.

Constructor & Destructor Documentation

◆ HKDF()

Botan::HKDF::HKDF ( std::unique_ptr< MessageAuthenticationCode prf)
inlineexplicit
Parameters
prfMAC algorithm to use

Definition at line 25 of file hkdf.h.

25: m_prf(std::move(prf)) {}

Member Function Documentation

◆ clone()

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

Definition at line 202 of file kdf.h.

202{ return this->new_object().release(); }
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}
#define BOTAN_UNUSED
Definition assert.h:118
static std::unique_ptr< HashFunction > create(std::string_view algo_spec, std::string_view provider="")
Definition hash.cpp:103
static std::unique_ptr< MessageAuthenticationCode > create(std::string_view algo_spec, std::string_view provider="")
Definition mac.cpp:50
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}
static std::unique_ptr< KDF > create(std::string_view algo_spec, std::string_view provider="")
Definition kdf.cpp:71
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() [1/6]

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 }
FE_25519 T
Definition ge.cpp:34

References T.

◆ derive_key() [2/6]

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 180 of file kdf.h.

184 {
185 return derive_key<T>(key_len,
186 secret,
187 secret_len,
188 cast_char_ptr_to_uint8(salt.data()),
189 salt.length(),
190 cast_char_ptr_to_uint8(label.data()),
191 label.length());
192 }
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() [3/6]

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 161 of file kdf.h.

165 {
166 return derive_key<T>(
167 key_len, secret.data(), secret.size(), salt, salt_len, cast_char_ptr_to_uint8(label.data()), label.size());
168 }

References Botan::cast_char_ptr_to_uint8().

◆ derive_key() [4/6]

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 143 of file kdf.h.

146 {
147 return derive_key<T>(
148 key_len, secret.data(), secret.size(), salt.data(), salt.size(), label.data(), label.size());
149 }

◆ derive_key() [5/6]

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().

◆ derive_key() [6/6]

void Botan::KDF::derive_key ( std::span< uint8_t >  key,
std::span< const uint8_t >  secret,
std::span< const uint8_t >  salt,
std::span< const uint8_t >  label 
) const
inlineinherited

Derive a key

Parameters
keythe output buffer for the to-be-derived key
secretthe secret input
salta diversifier
labelpurpose for the derived keying material

Definition at line 126 of file kdf.h.

129 {
130 return kdf(
131 key.data(), key.size(), secret.data(), secret.size(), salt.data(), salt.size(), label.data(), label.size());
132 }

◆ kdf()

void Botan::HKDF::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 25 of file hkdf.cpp.

32 {
33 HKDF_Extract extract(m_prf->new_object());
34 HKDF_Expand expand(m_prf->new_object());
35 secure_vector<uint8_t> prk(m_prf->output_length());
36
37 extract.kdf(prk.data(), prk.size(), secret, secret_len, salt, salt_len, nullptr, 0);
38 expand.kdf(key, key_len, prk.data(), prk.size(), nullptr, 0, label, label_len);
39}

References Botan::HKDF_Extract::kdf(), and Botan::HKDF_Expand::kdf().

◆ name()

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

Implements Botan::KDF.

Definition at line 21 of file hkdf.cpp.

21 {
22 return fmt("HKDF({})", m_prf->name());
23}

References Botan::fmt().

◆ new_object()

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

Implements Botan::KDF.

Definition at line 17 of file hkdf.cpp.

17 {
18 return std::make_unique<HKDF>(m_prf->new_object());
19}

◆ 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: