Botan 3.0.0-alpha0
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | List of all members
Botan::Argon2_Family Class Referencefinal

#include <argon2.h>

Inheritance diagram for Botan::Argon2_Family:
Botan::PasswordHashFamily

Public Member Functions

 Argon2_Family (uint8_t family)
 
std::unique_ptr< PasswordHashdefault_params () const override
 
std::unique_ptr< PasswordHashfrom_iterations (size_t iter) const override
 
std::unique_ptr< PasswordHashfrom_params (size_t M, size_t t, size_t p) const override
 
std::string name () const override
 
std::unique_ptr< PasswordHashtune (size_t output_length, std::chrono::milliseconds msec, size_t max_memory) const override
 

Static Public Member Functions

static std::unique_ptr< PasswordHashFamilycreate (const std::string &algo_spec, const std::string &provider="")
 
static std::unique_ptr< PasswordHashFamilycreate_or_throw (const std::string &algo_spec, const std::string &provider="")
 
static std::vector< std::string > providers (const std::string &algo_spec)
 

Detailed Description

Definition at line 73 of file argon2.h.

Constructor & Destructor Documentation

◆ Argon2_Family()

Botan::Argon2_Family::Argon2_Family ( uint8_t  family)

Definition at line 76 of file argon2pwhash.cpp.

76 : m_family(family)
77 {
78 if(m_family != 0 && m_family != 1 && m_family != 2)
79 throw Invalid_Argument("Unknown Argon2 family identifier");
80 }

Member Function Documentation

◆ create()

std::unique_ptr< PasswordHashFamily > Botan::PasswordHashFamily::create ( const std::string &  algo_spec,
const std::string &  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 49 of file pwdhash.cpp.

51 {
52 const SCAN_Name req(algo_spec);
53
54#if defined(BOTAN_HAS_PBKDF2)
55 if(req.algo_name() == "PBKDF2")
56 {
57 if(provider.empty() || provider == "base")
58 {
59 if(auto mac = MessageAuthenticationCode::create("HMAC(" + req.arg(0) + ")"))
60 return std::make_unique<PBKDF2_Family>(mac.release());
61
62 if(auto mac = MessageAuthenticationCode::create(req.arg(0)))
63 return std::make_unique<PBKDF2_Family>(mac.release());
64 }
65
66 return nullptr;
67 }
68#endif
69
70#if defined(BOTAN_HAS_SCRYPT)
71 if(req.algo_name() == "Scrypt")
72 {
73 return std::make_unique<Scrypt_Family>();
74 }
75#endif
76
77#if defined(BOTAN_HAS_ARGON2)
78 if(req.algo_name() == "Argon2d")
79 {
80 return std::make_unique<Argon2_Family>(static_cast<uint8_t>(0));
81 }
82 else if(req.algo_name() == "Argon2i")
83 {
84 return std::make_unique<Argon2_Family>(static_cast<uint8_t>(1));
85 }
86 else if(req.algo_name() == "Argon2id")
87 {
88 return std::make_unique<Argon2_Family>(static_cast<uint8_t>(2));
89 }
90#endif
91
92#if defined(BOTAN_HAS_PBKDF_BCRYPT)
93 if(req.algo_name() == "Bcrypt-PBKDF")
94 {
95 return std::make_unique<Bcrypt_PBKDF_Family>();
96 }
97#endif
98
99#if defined(BOTAN_HAS_PGP_S2K)
100 if(req.algo_name() == "OpenPGP-S2K" && req.arg_count() == 1)
101 {
102 if(auto hash = HashFunction::create(req.arg(0)))
103 {
104 return std::make_unique<RFC4880_S2K_Family>(hash.release());
105 }
106 }
107#endif
108
109 BOTAN_UNUSED(req);
110 BOTAN_UNUSED(provider);
111
112 return nullptr;
113 }
#define BOTAN_UNUSED(...)
Definition: assert.h:141
static std::unique_ptr< HashFunction > create(const std::string &algo_spec, const std::string &provider="")
Definition: hash.cpp:98
static std::unique_ptr< MessageAuthenticationCode > create(const std::string &algo_spec, const std::string &provider="")
Definition: mac.cpp:46
MechanismType hash

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

Referenced by botan_pwdhash(), botan_pwdhash_timed(), and Botan::PasswordHashFamily::create_or_throw().

◆ create_or_throw()

std::unique_ptr< PasswordHashFamily > Botan::PasswordHashFamily::create_or_throw ( const std::string &  algo_spec,
const std::string &  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 117 of file pwdhash.cpp.

119 {
120 if(auto pbkdf = PasswordHashFamily::create(algo, provider))
121 {
122 return pbkdf;
123 }
124 throw Lookup_Error("PasswordHashFamily", algo, provider);
125 }
static std::unique_ptr< PasswordHashFamily > create(const std::string &algo_spec, const std::string &provider="")
Definition: pwdhash.cpp:49

References Botan::PasswordHashFamily::create().

Referenced by Botan::argon2_check_pwhash(), Botan::argon2_generate_pwhash(), Botan::CryptoBox::decrypt_bin(), and Botan::CryptoBox::encrypt().

◆ default_params()

std::unique_ptr< PasswordHash > Botan::Argon2_Family::default_params ( ) const
overridevirtual

Return some default parameter set for this PBKDF that should be good enough for most users. The value returned may change over time as processing power and attacks improve.

Implements Botan::PasswordHashFamily.

Definition at line 151 of file argon2pwhash.cpp.

152 {
153 return this->from_params(128*1024, 1, 1);
154 }
std::unique_ptr< PasswordHash > from_params(size_t M, size_t t, size_t p) const override

References from_params().

Referenced by tune().

◆ from_iterations()

std::unique_ptr< PasswordHash > Botan::Argon2_Family::from_iterations ( size_t  iterations) const
overridevirtual

Return a parameter chosen based on a rough approximation with the specified iteration count. The exact value this returns for a particular algorithm may change from over time. Think of it as an alternative to tune, where time is expressed in terms of PBKDF2 iterations rather than milliseconds.

Implements Botan::PasswordHashFamily.

Definition at line 156 of file argon2pwhash.cpp.

157 {
158 /*
159 These choices are arbitrary, but should not change in future
160 releases since they will break applications expecting deterministic
161 mapping from iteration count to params
162 */
163 const size_t M = iter;
164 const size_t t = 1;
165 const size_t p = 1;
166 return this->from_params(M, t, p);
167 }

References from_params().

◆ from_params()

std::unique_ptr< PasswordHash > Botan::Argon2_Family::from_params ( size_t  i1,
size_t  i2,
size_t  i3 
) const
overridevirtual

Create a password hash using some scheme specific format. Parameters are as follows:

  • For PBKDF2, PGP-S2K, and Bcrypt-PBKDF, i1 is iterations
  • Scrypt uses N, r, p for i{1-3}
  • Argon2 family uses memory (in KB), iterations, and parallelism for i{1-3}

All unneeded parameters should be set to 0 or left blank.

Implements Botan::PasswordHashFamily.

Definition at line 169 of file argon2pwhash.cpp.

170 {
171 return std::make_unique<Argon2>(m_family, M, t, p);
172 }

Referenced by default_params(), from_iterations(), and tune().

◆ name()

std::string Botan::Argon2_Family::name ( ) const
overridevirtual
Returns
name of this PasswordHash

Implements Botan::PasswordHashFamily.

Definition at line 82 of file argon2pwhash.cpp.

83 {
84 return argon2_family_name(m_family);
85 }

◆ providers()

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

Definition at line 127 of file pwdhash.cpp.

128 {
129 return probe_providers_of<PasswordHashFamily>(algo_spec);
130 }

◆ tune()

std::unique_ptr< PasswordHash > Botan::Argon2_Family::tune ( size_t  output_length,
std::chrono::milliseconds  msec,
size_t  max_memory_usage_mb 
) const
overridevirtual

Return a new parameter set tuned for this machine

Parameters
output_lengthhow long the output length will be
msecthe desired execution time in milliseconds
max_memory_usage_mbsome password hash functions can use a tunable amount of memory, in this case max_memory_usage limits the amount of RAM the returned parameters will require, in mebibytes (2**20 bytes). It may require some small amount above the request. Set to zero to place no limit at all.

Implements Botan::PasswordHashFamily.

Definition at line 87 of file argon2pwhash.cpp.

90 {
91 const size_t max_kib = (max_memory == 0) ? 256*1024 : max_memory*1024;
92
93 // Tune with a large memory otherwise we measure cache vs RAM speeds and underestimate
94 // costs for larger params. Default is 36 MiB, or use 128 for long times.
95 const size_t tune_M = (msec >= std::chrono::milliseconds(500) ? 128 : 36) * 1024;
96 const size_t p = 1;
97 size_t t = 1;
98
99 Timer timer("Argon2");
100 const auto tune_time = BOTAN_PBKDF_TUNING_TIME;
101
102 auto pwhash = this->from_params(tune_M, t, p);
103
104 timer.run_until_elapsed(tune_time, [&]() {
105 uint8_t output[64] = { 0 };
106 pwhash->derive_key(output, sizeof(output),
107 "test", 4,
108 nullptr, 0);
109 });
110
111 if(timer.events() == 0 || timer.value() == 0)
112 return default_params();
113
114 size_t M = 4*1024;
115
116 const uint64_t measured_time = timer.value() / (timer.events() * (tune_M / M));
117
118 const uint64_t target_nsec = msec.count() * static_cast<uint64_t>(1000000);
119
120 /*
121 * Argon2 scaling rules:
122 * k*M, k*t, k*p all increase cost by about k
123 *
124 * Since we don't even take advantage of p > 1, we prefer increasing
125 * t or M instead.
126 *
127 * If possible to increase M, prefer that.
128 */
129
130 uint64_t est_nsec = measured_time;
131
132 if(est_nsec < target_nsec && M < max_kib)
133 {
134 const uint64_t desired_cost_increase = (target_nsec + est_nsec - 1) / est_nsec;
135 const uint64_t mem_headroom = max_kib / M;
136
137 const uint64_t M_mult = std::min(desired_cost_increase, mem_headroom);
138 M *= static_cast<size_t>(M_mult);
139 est_nsec *= M_mult;
140 }
141
142 if(est_nsec < target_nsec)
143 {
144 const uint64_t desired_cost_increase = (target_nsec + est_nsec - 1) / est_nsec;
145 t *= static_cast<size_t>(desired_cost_increase);
146 }
147
148 return this->from_params(M, t, p);
149 }
std::unique_ptr< PasswordHash > default_params() const override
#define BOTAN_PBKDF_TUNING_TIME
Definition: build.h:447

References BOTAN_PBKDF_TUNING_TIME, default_params(), Botan::Timer::events(), from_params(), Botan::Timer::run_until_elapsed(), and Botan::Timer::value().


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