Botan 3.6.1
Crypto and TLS for C&
Botan::RFC4880_S2K Class Referencefinal

#include <pgp_s2k.h>

Inheritance diagram for Botan::RFC4880_S2K:
Botan::PasswordHash

Public Member Functions

virtual void derive_key (uint8_t out[], size_t out_len, const char *password, size_t password_len, const uint8_t salt[], size_t salt_len, const uint8_t ad[], size_t ad_len, const uint8_t key[], size_t key_len) const
 
void derive_key (uint8_t out[], size_t out_len, const char *password, size_t password_len, const uint8_t salt[], size_t salt_len) const override
 
void hash (std::span< uint8_t > out, std::string_view password, std::span< const uint8_t > salt) const
 
void hash (std::span< uint8_t > out, std::string_view password, std::span< const uint8_t > salt, std::span< const uint8_t > associated_data, std::span< const uint8_t > key) const
 
size_t iterations () const override
 
virtual size_t memory_param () const
 
virtual size_t parallelism () const
 
 RFC4880_S2K (std::unique_ptr< HashFunction > hash, size_t iterations)
 
virtual bool supports_associated_data () const
 
virtual bool supports_keyed_operation () const
 
std::string to_string () const override
 
virtual size_t total_memory_usage () const
 

Detailed Description

OpenPGP's S2K

See RFC 4880 sections 3.7.1.1, 3.7.1.2, and 3.7.1.3 If the salt is empty and iterations == 1, "simple" S2K is used If the salt is non-empty and iterations == 1, "salted" S2K is used If the salt is non-empty and iterations > 1, "iterated" S2K is used

Note that unlike PBKDF2, OpenPGP S2K's "iterations" are defined as the number of bytes hashed.

Definition at line 80 of file pgp_s2k.h.

Constructor & Destructor Documentation

◆ RFC4880_S2K()

Botan::RFC4880_S2K::RFC4880_S2K ( std::unique_ptr< HashFunction > hash,
size_t iterations )
Parameters
hashthe hash function to use
iterationsis rounded due to PGP formatting

Definition at line 128 of file pgp_s2k.cpp.

128 :
129 m_hash(std::move(hash)), m_iterations(iterations) {}
void hash(std::span< uint8_t > out, std::string_view password, std::span< const uint8_t > salt) const
Definition pwdhash.h:84
size_t iterations() const override
Definition pgp_s2k.h:90

Member Function Documentation

◆ derive_key() [1/2]

void Botan::PasswordHash::derive_key ( uint8_t out[],
size_t out_len,
const char * password,
size_t password_len,
const uint8_t salt[],
size_t salt_len,
const uint8_t ad[],
size_t ad_len,
const uint8_t key[],
size_t key_len ) const
virtualinherited

Derive a key from a password plus additional data and/or a secret key

Currently this is only supported for Argon2. Using a non-empty AD or key with other algorithms will cause a Not_Implemented exception.

Parameters
outbuffer to store the derived key, must be of out_len bytes
out_lenthe desired length of the key to produce
passwordthe password to derive the key from
password_lenthe length of password in bytes
salta randomly chosen salt
salt_lenlength of salt in bytes
adsome additional data
ad_lenlength of ad in bytes
keya secret key
key_lenlength of key in bytes

This function is const, but is not thread safe. Different threads should either use unique objects, or serialize all access.

Reimplemented in Botan::Argon2.

Definition at line 34 of file pwdhash.cpp.

43 {
44 BOTAN_UNUSED(ad, key);
45
46 if(ad_len == 0 && key_len == 0) {
47 return this->derive_key(out, out_len, password, password_len, salt, salt_len);
48 } else {
49 throw Not_Implemented("PasswordHash " + this->to_string() + " does not support AD or key");
50 }
51}
#define BOTAN_UNUSED
Definition assert.h:118
virtual void derive_key(uint8_t out[], size_t out_len, const char *password, size_t password_len, const uint8_t salt[], size_t salt_len) const =0
virtual std::string to_string() const =0

References BOTAN_UNUSED, Botan::PasswordHash::derive_key(), and Botan::PasswordHash::to_string().

◆ derive_key() [2/2]

void Botan::RFC4880_S2K::derive_key ( uint8_t out[],
size_t out_len,
const char * password,
size_t password_len,
const uint8_t salt[],
size_t salt_len ) const
overridevirtual

Derive a key from a password

Parameters
outbuffer to store the derived key, must be of out_len bytes
out_lenthe desired length of the key to produce
passwordthe password to derive the key from
password_lenthe length of password in bytes
salta randomly chosen salt
salt_lenlength of salt in bytes

This function is const, but is not thread safe. Different threads should either use unique objects, or serialize all access.

Implements Botan::PasswordHash.

Definition at line 135 of file pgp_s2k.cpp.

140 {
141 pgp_s2k(*m_hash, out, out_len, password, password_len, salt, salt_len, m_iterations);
142}

◆ hash() [1/2]

void Botan::PasswordHash::hash ( std::span< uint8_t > out,
std::string_view password,
std::span< const uint8_t > salt ) const
inlineinherited

Hash a password into a bitstring

Derive a key from the specified password and salt, placing it into out.

Parameters
outa span where the derived key will be placed
passwordthe password to derive the key from
salta randomly chosen salt

This function is const, but is not thread safe. Different threads should either use unique objects, or serialize all access.

Definition at line 84 of file pwdhash.h.

84 {
85 this->derive_key(out.data(), out.size(), password.data(), password.size(), salt.data(), salt.size());
86 }

◆ hash() [2/2]

void Botan::PasswordHash::hash ( std::span< uint8_t > out,
std::string_view password,
std::span< const uint8_t > salt,
std::span< const uint8_t > associated_data,
std::span< const uint8_t > key ) const
inlineinherited

Hash a password into a bitstring

Derive a key from the specified password, salt, associated_data, and secret key, placing it into out. The associated_data and key are both allowed to be empty. Currently non-empty AD/key is only supported with Argon2.

Parameters
outa span where the derived key will be placed
passwordthe password to derive the key from
salta randomly chosen salt
associated_datasome additional data
keya secret key

This function is const, but is not thread safe. Different threads should either use unique objects, or serialize all access.

Definition at line 105 of file pwdhash.h.

109 {
110 this->derive_key(out.data(),
111 out.size(),
112 password.data(),
113 password.size(),
114 salt.data(),
115 salt.size(),
116 associated_data.data(),
117 associated_data.size(),
118 key.data(),
119 key.size());
120 }

◆ iterations()

size_t Botan::RFC4880_S2K::iterations ( ) const
inlineoverridevirtual

Most password hashes have some notion of iterations.

Implements Botan::PasswordHash.

Definition at line 90 of file pgp_s2k.h.

90{ return m_iterations; }

◆ memory_param()

virtual size_t Botan::PasswordHash::memory_param ( ) const
inlinevirtualinherited

Some password hashing algorithms have a parameter which controls how much memory is used. If not supported by some algorithm, returns 0.

Reimplemented in Botan::Argon2, Botan::Bcrypt_PBKDF, and Botan::Scrypt.

Definition at line 40 of file pwdhash.h.

40{ return 0; }

◆ parallelism()

virtual size_t Botan::PasswordHash::parallelism ( ) const
inlinevirtualinherited

Some password hashing algorithms have a parallelism parameter. If the algorithm does not support this notion, then the function returns zero. This allows distinguishing between a password hash which just does not support parallel operation, vs one that does support parallel operation but which has been configured to use a single lane.

Reimplemented in Botan::Argon2, Botan::Bcrypt_PBKDF, and Botan::Scrypt.

Definition at line 50 of file pwdhash.h.

50{ return 0; }

◆ supports_associated_data()

virtual bool Botan::PasswordHash::supports_associated_data ( ) const
inlinevirtualinherited
Returns
true if this password hash supports supplying associated data

Reimplemented in Botan::Argon2.

Definition at line 69 of file pwdhash.h.

69{ return false; }

◆ supports_keyed_operation()

virtual bool Botan::PasswordHash::supports_keyed_operation ( ) const
inlinevirtualinherited
Returns
true if this password hash supports supplying a key

Reimplemented in Botan::Argon2.

Definition at line 64 of file pwdhash.h.

64{ return false; }

◆ to_string()

std::string Botan::RFC4880_S2K::to_string ( ) const
overridevirtual

Implements Botan::PasswordHash.

Definition at line 131 of file pgp_s2k.cpp.

131 {
132 return fmt("OpenPGP-S2K({},{})", m_hash->name(), m_iterations);
133}
std::string fmt(std::string_view format, const T &... args)
Definition fmt.h:53

References Botan::fmt().

◆ total_memory_usage()

virtual size_t Botan::PasswordHash::total_memory_usage ( ) const
inlinevirtualinherited

Returns an estimate of the total number of bytes required to perform this key derivation.

If this algorithm uses a small and constant amount of memory, with no effort made towards being memory hard, this function returns 0.

Reimplemented in Botan::Argon2, Botan::Bcrypt_PBKDF, and Botan::Scrypt.

Definition at line 59 of file pwdhash.h.

59{ return 0; }

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