Botan 3.0.0-alpha0
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | List of all members
Botan::RFC4880_S2K_Family Class Referencefinal

#include <pgp_s2k.h>

Inheritance diagram for Botan::RFC4880_S2K_Family:
Botan::PasswordHashFamily

Public Member Functions

std::unique_ptr< PasswordHashdefault_params () const override
 
std::unique_ptr< PasswordHashfrom_iterations (size_t iter) const override
 
std::unique_ptr< PasswordHashfrom_params (size_t iter, size_t, size_t) const override
 
std::string name () const override
 
 RFC4880_S2K_Family (HashFunction *hash)
 
std::unique_ptr< PasswordHashtune (size_t output_len, std::chrono::milliseconds msec, size_t max_mem) 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 112 of file pgp_s2k.h.

Constructor & Destructor Documentation

◆ RFC4880_S2K_Family()

Botan::RFC4880_S2K_Family::RFC4880_S2K_Family ( HashFunction hash)
inline

Definition at line 115 of file pgp_s2k.h.

115: m_hash(hash) {}
MechanismType hash

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

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::RFC4880_S2K_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 130 of file pgp_s2k.cpp.

131 {
132 return std::make_unique<RFC4880_S2K>(m_hash->clone(), 50331648);
133 }

◆ from_iterations()

std::unique_ptr< PasswordHash > Botan::RFC4880_S2K_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 135 of file pgp_s2k.cpp.

136 {
137 return std::make_unique<RFC4880_S2K>(m_hash->clone(), iter);
138 }

◆ from_params()

std::unique_ptr< PasswordHash > Botan::RFC4880_S2K_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 125 of file pgp_s2k.cpp.

126 {
127 return std::make_unique<RFC4880_S2K>(m_hash->clone(), iter);
128 }

◆ name()

std::string Botan::RFC4880_S2K_Family::name ( ) const
overridevirtual
Returns
name of this PasswordHash

Implements Botan::PasswordHashFamily.

Definition at line 96 of file pgp_s2k.cpp.

97 {
98 return "OpenPGP-S2K(" + m_hash->name() + ")";
99 }

◆ 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::RFC4880_S2K_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 101 of file pgp_s2k.cpp.

102 {
103 const auto tune_time = BOTAN_PBKDF_TUNING_TIME;
104
105 const size_t buf_size = 1024;
106 std::vector<uint8_t> buffer(buf_size);
107
108 Timer timer("RFC4880_S2K", buf_size);
109 timer.run_until_elapsed(tune_time, [&]() {
110 m_hash->update(buffer);
111 });
112
113 const double hash_bytes_per_second = timer.bytes_per_second();
114 const uint64_t desired_nsec = msec.count() * 1000000;
115
116 const size_t hash_size = m_hash->output_length();
117 const size_t blocks_required = (output_len <= hash_size ? 1 : (output_len + hash_size - 1) / hash_size);
118
119 const double bytes_to_be_hashed = (hash_bytes_per_second * (desired_nsec / 1000000000.0)) / blocks_required;
120 const size_t iterations = RFC4880_round_iterations(static_cast<size_t>(bytes_to_be_hashed));
121
122 return std::make_unique<RFC4880_S2K>(m_hash->clone(), iterations);
123 }
#define BOTAN_PBKDF_TUNING_TIME
Definition: build.h:447
size_t RFC4880_round_iterations(size_t iterations)
Definition: rfc4880.h:32

References BOTAN_PBKDF_TUNING_TIME, Botan::Timer::bytes_per_second(), Botan::RFC4880_round_iterations(), and Botan::Timer::run_until_elapsed().

Referenced by Botan::OpenPGP_S2K::pbkdf().


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