Botan::RFC4880_S2K Class Reference

#include <pgp_s2k.h>

Inheritance diagram for Botan::RFC4880_S2K:

Public Member Functions
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
size_t	iterations () const override
virtual size_t	memory_param () const
virtual size_t	parallelism () const
	RFC4880_S2K (HashFunction *hash, size_t iterations)
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 106 of file pgp_s2k.h.

Constructor & Destructor Documentation

RFC4880_S2K()

Botan::RFC4880_S2K::RFC4880_S2K	(	HashFunction *	hash,
		size_t	iterations
	)

Parameters

hash	the hash function to use
iterations	is rounded due to PGP formatting

Definition at line 198 of file pgp_s2k.cpp.

                                                              :
   m_hash(hash),
   m_iterations(iterations)
   {
   }

Member Function Documentation

derive_key()

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

out	buffer to store the derived key, must be of out_len bytes
out_len	the desired length of the key to produce
password	the password to derive the key from
password_len	the length of password in bytes
salt	a randomly chosen salt
salt_len	length 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 209 of file pgp_s2k.cpp.

References salt_len.

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

iterations()

size_t Botan::RFC4880_S2K::iterations ( ) const

inlineoverridevirtual

Most password hashes have some notion of iterations.

Implements Botan::PasswordHash.

Definition at line 117 of file pgp_s2k.h.

{ 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::Scrypt, and Botan::Bcrypt_PBKDF.

Definition at line 40 of file pwdhash.h.

{ 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::Scrypt, and Botan::Bcrypt_PBKDF.

Definition at line 50 of file pwdhash.h.

{ return 0; }

to_string()

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

overridevirtual

Implements Botan::PasswordHash.

Definition at line 204 of file pgp_s2k.cpp.

References Botan::ASN1::to_string().

   {
   return "OpenPGP-S2K(" + m_hash->name() + "," + std::to_string(m_iterations) + ")";
   }

total_memory_usage()

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

inlinevirtualinherited

Returns an estimate of the total memory usage 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::Scrypt, and Botan::Bcrypt_PBKDF.

Definition at line 59 of file pwdhash.h.

{ return 0; }

---

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

• src/lib/pbkdf/pgp_s2k/pgp_s2k.h
• src/lib/pbkdf/pgp_s2k/pgp_s2k.cpp