Botan 3.8.1
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

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
 
template<size_t key_len>
std::array< uint8_t, key_len > derive_key (std::span< const uint8_t > secret, std::span< const uint8_t > salt={}, std::span< const uint8_t > label={})
 
template<size_t key_len>
std::array< uint8_t, key_len > derive_key (std::span< const uint8_t > secret, std::span< const uint8_t > salt={}, std::string_view label="")
 
template<size_t key_len>
std::array< uint8_t, key_len > derive_key (std::span< const uint8_t > secret, std::string_view salt="", std::string_view label="")
 
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
 
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

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 242 of file kdf.h.

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

References new_object().

◆ 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 72 of file kdf.cpp.

72 {
73 const SCAN_Name req(algo_spec);
74
75#if defined(BOTAN_HAS_HKDF)
76 if(req.algo_name() == "HKDF" && req.arg_count() == 1) {
77 if(provider.empty() || provider == "base") {
78 return kdf_create_mac_or_hash<HKDF>(req.arg(0));
79 }
80 }
81
82 if(req.algo_name() == "HKDF-Extract" && req.arg_count() == 1) {
83 if(provider.empty() || provider == "base") {
84 return kdf_create_mac_or_hash<HKDF_Extract>(req.arg(0));
85 }
86 }
87
88 if(req.algo_name() == "HKDF-Expand" && req.arg_count() == 1) {
89 if(provider.empty() || provider == "base") {
90 return kdf_create_mac_or_hash<HKDF_Expand>(req.arg(0));
91 }
92 }
93#endif
94
95#if defined(BOTAN_HAS_KDF2)
96 if(req.algo_name() == "KDF2" && req.arg_count() == 1) {
97 if(provider.empty() || provider == "base") {
98 if(auto hash = HashFunction::create(req.arg(0))) {
99 return std::make_unique<KDF2>(std::move(hash));
100 }
101 }
102 }
103#endif
104
105#if defined(BOTAN_HAS_KDF1_18033)
106 if(req.algo_name() == "KDF1-18033" && req.arg_count() == 1) {
107 if(provider.empty() || provider == "base") {
108 if(auto hash = HashFunction::create(req.arg(0))) {
109 return std::make_unique<KDF1_18033>(std::move(hash));
110 }
111 }
112 }
113#endif
114
115#if defined(BOTAN_HAS_KDF1)
116 if(req.algo_name() == "KDF1" && req.arg_count() == 1) {
117 if(provider.empty() || provider == "base") {
118 if(auto hash = HashFunction::create(req.arg(0))) {
119 return std::make_unique<KDF1>(std::move(hash));
120 }
121 }
122 }
123#endif
124
125#if defined(BOTAN_HAS_TLS_V12_PRF)
126 if(req.algo_name() == "TLS-12-PRF" && req.arg_count() == 1) {
127 if(provider.empty() || provider == "base") {
128 return kdf_create_mac_or_hash<TLS_12_PRF>(req.arg(0));
129 }
130 }
131#endif
132
133#if defined(BOTAN_HAS_X942_PRF)
134 if(req.algo_name() == "X9.42-PRF" && req.arg_count() == 1) {
135 if(provider.empty() || provider == "base") {
136 return std::make_unique<X942_PRF>(req.arg(0));
137 }
138 }
139#endif
140
141#if defined(BOTAN_HAS_SP800_108)
142 if(req.algo_name() == "SP800-108-Counter" && req.arg_count_between(1, 3)) {
143 if(provider.empty() || provider == "base") {
144 return kdf_create_mac_or_hash<SP800_108_Counter>(
145 req.arg(0), req.arg_as_integer(1, 32), req.arg_as_integer(2, 32));
146 }
147 }
148
149 if(req.algo_name() == "SP800-108-Feedback" && req.arg_count_between(1, 3)) {
150 if(provider.empty() || provider == "base") {
151 return kdf_create_mac_or_hash<SP800_108_Feedback>(
152 req.arg(0), req.arg_as_integer(1, 32), req.arg_as_integer(2, 32));
153 }
154 }
155
156 if(req.algo_name() == "SP800-108-Pipeline" && req.arg_count_between(1, 3)) {
157 if(provider.empty() || provider == "base") {
158 return kdf_create_mac_or_hash<SP800_108_Pipeline>(
159 req.arg(0), req.arg_as_integer(1, 32), req.arg_as_integer(2, 32));
160 }
161 }
162#endif
163
164#if defined(BOTAN_HAS_SP800_56A)
165 if(req.algo_name() == "SP800-56A" && req.arg_count() == 1) {
166 if(auto hash = HashFunction::create(req.arg(0))) {
167 return std::make_unique<SP800_56C_One_Step_Hash>(std::move(hash));
168 }
169 if(req.arg(0) == "KMAC-128") {
170 return std::make_unique<SP800_56C_One_Step_KMAC128>();
171 }
172 if(req.arg(0) == "KMAC-256") {
173 return std::make_unique<SP800_56C_One_Step_KMAC256>();
174 }
175 if(auto mac = MessageAuthenticationCode::create(req.arg(0))) {
176 return std::make_unique<SP800_56C_One_Step_HMAC>(std::move(mac));
177 }
178 }
179#endif
180
181#if defined(BOTAN_HAS_SP800_56C)
182 if(req.algo_name() == "SP800-56C" && req.arg_count() == 1) {
183 std::unique_ptr<KDF> exp(kdf_create_mac_or_hash<SP800_108_Feedback>(req.arg(0), 32, 32));
184 if(exp) {
185 if(auto mac = MessageAuthenticationCode::create(req.arg(0))) {
186 return std::make_unique<SP800_56C_Two_Step>(std::move(mac), std::move(exp));
187 }
188
189 if(auto mac = MessageAuthenticationCode::create(fmt("HMAC({})", req.arg(0)))) {
190 return std::make_unique<SP800_56C_Two_Step>(std::move(mac), std::move(exp));
191 }
192 }
193 }
194#endif
195
196 BOTAN_UNUSED(req);
197 BOTAN_UNUSED(provider);
198
199 return nullptr;
200}
BOTAN_UNUSED
#define BOTAN_UNUSED
Definition assert.h:120
Botan::HashFunction::create
static std::unique_ptr< HashFunction > create(std::string_view algo_spec, std::string_view provider="")
Definition hash.cpp:107
Botan::MessageAuthenticationCode::create
static std::unique_ptr< MessageAuthenticationCode > create(std::string_view algo_spec, std::string_view provider="")
Definition mac.cpp:51
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_as_integer(), Botan::SCAN_Name::arg_count(), Botan::SCAN_Name::arg_count_between(), BOTAN_UNUSED, Botan::HashFunction::create(), Botan::MessageAuthenticationCode::create(), and Botan::fmt().

Referenced by create_or_throw(), and ~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 203 of file kdf.cpp.

203 {
204 if(auto kdf = KDF::create(algo, provider)) {
205 return kdf;
206 }
207 throw Lookup_Error("KDF", algo, provider);
208}
Botan::KDF::create
static std::unique_ptr< KDF > create(std::string_view algo_spec, std::string_view provider="")
Definition kdf.cpp:72
Botan::KDF::kdf
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
Definition kdf.h:67

References create(), and kdf().

Referenced by botan_kdf(), Botan::ECIES_KA_Operation::derive_secret(), Botan::get_kdf(), 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(), Botan::TLS::Handshake_State::protocol_specific_prf(), and ~KDF().

◆ derive_key() [1/9]

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 91 of file kdf.h.

97 {
98 return derive_key<T>(key_len, {secret, secret_len}, {salt, salt_len}, {label, label_len});
99 }
Botan::KDF::derive_key
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
Definition kdf.h:91

References derive_key().

Referenced by derive_key(), derive_key(), derive_key(), derive_key(), derive_key(), Botan::hkdf_expand_label(), and kdf().

◆ derive_key() [2/9]

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 179 of file kdf.h.

183 {
184 return derive_key<T>(key_len, {secret, secret_len}, _as_span(salt), _as_span(label));
185 }

References derive_key().

◆ derive_key() [3/9]

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 160 of file kdf.h.

164 {
165 return derive_key<T>(key_len, secret, {salt, salt_len}, _as_span(label));
166 }

References derive_key().

◆ derive_key() [4/9]

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 140 of file kdf.h.

143 {
144 T key(key_len);
145 perform_kdf(key, secret, salt, label);
146 return key;
147 }
Botan::KDF::perform_kdf
virtual void perform_kdf(std::span< uint8_t > key, std::span< const uint8_t > secret, std::span< const uint8_t > salt, std::span< const uint8_t > label) const =0

References perform_kdf().

◆ derive_key() [5/9]

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 110 of file kdf.h.

113 {
114 return derive_key<T>(key_len, secret, _as_span(salt), _as_span(label));
115 }

References derive_key().

◆ derive_key() [6/9]

template<size_t key_len>
std::array< uint8_t, key_len > Botan::KDF::derive_key ( std::span< const uint8_t > secret,
std::span< const uint8_t > salt = {},
std::span< const uint8_t > label = {} )
inlineinherited

Derive a key

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

Definition at line 196 of file kdf.h.

197 {},
198 std::span<const uint8_t> label = {}) {
199 std::array<uint8_t, key_len> key;
200 perform_kdf(key, secret, salt, label);
201 return key;
202 }

◆ derive_key() [7/9]

template<size_t key_len>
std::array< uint8_t, key_len > Botan::KDF::derive_key ( std::span< const uint8_t > secret,
std::span< const uint8_t > salt = {},
std::string_view label = "" )
inlineinherited

Derive a key

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

Definition at line 213 of file kdf.h.

214 {},
215 std::string_view label = "") {
216 return derive_key<key_len>(secret, salt, _as_span(label));
217 }

◆ derive_key() [8/9]

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

Derive a key

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

Definition at line 228 of file kdf.h.

230 {
231 return derive_key<key_len>(secret, _as_span(salt), _as_span(label));
232 }

References derive_key().

◆ derive_key() [9/9]

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 124 of file kdf.h.

127 {
128 perform_kdf(key, secret, salt, label);
129 }

References perform_kdf().

◆ kdf()

void Botan::KDF::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
inlineinherited

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

Definition at line 67 of file kdf.h.

74 {
75 derive_key({key, key_len}, {secret, secret_len}, {salt, salt_len}, {label, label_len});
76 }

References derive_key(), and kdf().

Referenced by create_or_throw(), and kdf().

◆ name()

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

Implements Botan::KDF.

Definition at line 23 of file hkdf.cpp.

23 {
24 return fmt("HKDF({})", m_prf->name());
25}

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 19 of file hkdf.cpp.

19 {
20 return std::make_unique<HKDF>(m_prf->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 210 of file kdf.cpp.

210 {
211 return probe_providers_of<KDF>(algo_spec);
212}
Botan::probe_providers_of
std::vector< std::string > probe_providers_of(std::string_view algo_spec, const std::vector< std::string > &possible={"base"})
Definition scan_name.h:105

References Botan::probe_providers_of().

Referenced by ~KDF().

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