Botan::OpenPGP_S2K Class Reference

#include <pgp_s2k.h>

Inheritance diagram for Botan::OpenPGP_S2K:

Public Member Functions
PBKDF *	clone () const
template<typename Alloc>
OctetString	derive_key (size_t out_len, std::string_view passphrase, const std::vector< uint8_t, Alloc > &salt, size_t iterations) const
template<typename Alloc>
OctetString	derive_key (size_t out_len, std::string_view passphrase, const std::vector< uint8_t, Alloc > &salt, std::chrono::milliseconds msec, size_t &iterations) const
OctetString	derive_key (size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations) const
OctetString	derive_key (size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, std::chrono::milliseconds msec, size_t &iterations) const
std::string	name () const override
std::unique_ptr< PBKDF >	new_object () const override
	OpenPGP_S2K (std::unique_ptr< HashFunction > hash)
size_t	pbkdf (uint8_t output_buf[], size_t output_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations, std::chrono::milliseconds msec) const override
secure_vector< uint8_t >	pbkdf_iterations (size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations) const
void	pbkdf_iterations (uint8_t out[], size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations) const
secure_vector< uint8_t >	pbkdf_timed (size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, std::chrono::milliseconds msec, size_t &iterations) const
void	pbkdf_timed (uint8_t out[], size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, std::chrono::milliseconds msec, size_t &iterations) const

Static Public Member Functions
static std::unique_ptr< PBKDF >	create (std::string_view algo_spec, std::string_view provider="")
static std::unique_ptr< PBKDF >	create_or_throw (std::string_view algo_spec, std::string_view provider="")
static size_t	decode_count (uint8_t encoded_iter)
static uint8_t	encode_count (size_t iterations)
static std::vector< std::string >	providers (std::string_view algo_spec)

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

Due to complexities of the PGP S2K algorithm, time-based derivation is not supported. So if iterations == 0 and msec.count() > 0, an exception is thrown. In the future this may be supported, in which case "iterated" S2K will be used and the number of iterations performed is returned.

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

Definition at line 39 of file pgp_s2k.h.

Constructor & Destructor Documentation

OpenPGP_S2K()

Botan::OpenPGP_S2K::OpenPGP_S2K ( std::unique_ptr< HashFunction > hash )

inlineexplicit

Parameters

hash	the hash function to use

Definition at line 44 of file pgp_s2k.h.

: m_hash(std::move(hash)) {}

Member Function Documentation

clone()

PBKDF * Botan::PBKDF::clone ( ) const

inlineinherited

Returns

new instance of this same algorithm

Definition at line 65 of file pbkdf.h.

{ return this->new_object().release(); }

References new_object().

create()

std::unique_ptr< PBKDF > Botan::PBKDF::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_spec	algorithm name
provider	provider implementation to choose

Returns

a null pointer if the algo/provider combination cannot be found

Definition at line 24 of file pbkdf.cpp.

                                                                                    {
   const SCAN_Name req(algo_spec);
 
#if defined(BOTAN_HAS_PBKDF2)
   if(req.algo_name() == "PBKDF2") {
      if(provider.empty() || provider == "base") {
         if(auto mac = MessageAuthenticationCode::create("HMAC(" + req.arg(0) + ")")) {
            return std::make_unique<PKCS5_PBKDF2>(std::move(mac));
         }
 
         if(auto mac = MessageAuthenticationCode::create(req.arg(0))) {
            return std::make_unique<PKCS5_PBKDF2>(std::move(mac));
         }
      }
 
      return nullptr;
   }
#endif
 
#if defined(BOTAN_HAS_PGP_S2K)
   if(req.algo_name() == "OpenPGP-S2K" && req.arg_count() == 1) {
      if(auto hash = HashFunction::create(req.arg(0))) {
         return std::make_unique<OpenPGP_S2K>(std::move(hash));
      }
   }
#endif
 
   BOTAN_UNUSED(req, provider);
 
   return nullptr;
}

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

Referenced by create_or_throw().

create_or_throw()

std::unique_ptr< PBKDF > Botan::PBKDF::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 57 of file pbkdf.cpp.

                                                                                        {
   if(auto pbkdf = PBKDF::create(algo, provider)) {
      return pbkdf;
   }
   throw Lookup_Error("PBKDF", algo, provider);
}

References create(), and pbkdf().

Referenced by Botan::get_pbkdf(), and Botan::get_s2k().

decode_count()

static size_t Botan::OpenPGP_S2K::decode_count ( uint8_t encoded_iter )

inlinestatic

Definition at line 63 of file pgp_s2k.h.

{ return RFC4880_decode_count(encoded_iter); }

References Botan::RFC4880_decode_count().

derive_key() [1/4]

template<typename Alloc>

OctetString Botan::PBKDF::derive_key ( size_t out_len, std::string_view passphrase, const std::vector< uint8_t, Alloc > & salt, size_t iterations ) const

inlineinherited

Derive a key from a passphrase

Parameters

out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
iterations	the number of iterations to use (use 10K or more)

Definition at line 189 of file pbkdf.h.

                                                      {
         return OctetString(pbkdf_iterations(out_len, passphrase, salt.data(), salt.size(), iterations));
      }

References pbkdf_iterations().

derive_key() [2/4]

template<typename Alloc>

OctetString Botan::PBKDF::derive_key ( size_t out_len, std::string_view passphrase, const std::vector< uint8_t, Alloc > & salt, std::chrono::milliseconds msec, size_t & iterations ) const

inlineinherited

Derive a key from a passphrase using a certain amount of time

Parameters

out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
msec	is how long to run the PBKDF
iterations	is set to the number of iterations used

Definition at line 223 of file pbkdf.h.

                                                       {
         return OctetString(pbkdf_timed(out_len, passphrase, salt.data(), salt.size(), msec, iterations));
      }

References pbkdf_timed().

derive_key() [3/4]

OctetString Botan::PBKDF::derive_key ( size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations ) const

inlineinherited

Derive a key from a passphrase

Parameters

out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
iterations	the number of iterations to use (use 10K or more)

Definition at line 176 of file pbkdf.h.

                                                                                                                    {
         return OctetString(pbkdf_iterations(out_len, passphrase, salt, salt_len, iterations));
      }

References pbkdf_iterations().

Referenced by Botan::check_passhash9(), and Botan::generate_passhash9().

derive_key() [4/4]

OctetString Botan::PBKDF::derive_key ( size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, std::chrono::milliseconds msec, size_t & iterations ) const

inlineinherited

Derive a key from a passphrase

Parameters

out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
msec	is how long to run the PBKDF
iterations	is set to the number of iterations used

Definition at line 205 of file pbkdf.h.

                                                       {
         return OctetString(pbkdf_timed(out_len, passphrase, salt, salt_len, msec, iterations));
      }

References pbkdf_timed().

encode_count()

static uint8_t Botan::OpenPGP_S2K::encode_count ( size_t iterations )

inlinestatic

RFC 4880 encodes the iteration count to a single-byte value

Definition at line 61 of file pgp_s2k.h.

{ return RFC4880_encode_count(iterations); }

References Botan::RFC4880_encode_count().

name()

std::string Botan::OpenPGP_S2K::name ( ) const

inlineoverridevirtual

Returns

name of this PBKDF

Implements Botan::PBKDF.

Definition at line 46 of file pgp_s2k.h.

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

new_object()

std::unique_ptr< PBKDF > Botan::OpenPGP_S2K::new_object ( ) const

inlineoverridevirtual

Returns

new instance of this same algorithm

Implements Botan::PBKDF.

Definition at line 48 of file pgp_s2k.h.

{ return std::make_unique<OpenPGP_S2K>(m_hash->new_object()); }

pbkdf()

size_t Botan::OpenPGP_S2K::pbkdf ( uint8_t out[], size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations, std::chrono::milliseconds msec ) const

overridevirtual

Derive a key from a passphrase for a number of iterations specified by either iterations or if iterations == 0 then running until msec time has elapsed.

Parameters

out	buffer to store the derived key, must be of out_len bytes
out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
iterations	the number of iterations to use (use 10K or more)
msec	if iterations is zero, then instead the PBKDF is run until msec milliseconds has passed.

Returns

the number of iterations performed

Implements Botan::PBKDF.

Definition at line 72 of file pgp_s2k.cpp.

                                                            {
   std::unique_ptr<PasswordHash> pwdhash;
 
   if(iterations == 0) {
      RFC4880_S2K_Family s2k_params(m_hash->new_object());
      iterations = s2k_params.tune(output_len, msec, 0, std::chrono::milliseconds(10))->iterations();
   }
 
   pgp_s2k(*m_hash, output_buf, output_len, password.data(), password.size(), salt, salt_len, iterations);
 
   return iterations;
}

References Botan::RFC4880_S2K_Family::tune().

pbkdf_iterations() [1/2]

secure_vector< uint8_t > Botan::PBKDF::pbkdf_iterations ( size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations ) const

inherited

Derive a key from a passphrase for a number of iterations.

Parameters

out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
iterations	the number of iterations to use (use 10K or more)

Returns

the derived key

Definition at line 93 of file pbkdf.cpp.

                                                                                                              {
   secure_vector<uint8_t> out(out_len);
   pbkdf_iterations(out.data(), out_len, passphrase, salt, salt_len, iterations);
   return out;
}

References pbkdf_iterations().

pbkdf_iterations() [2/2]

void Botan::PBKDF::pbkdf_iterations ( uint8_t out[], size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, size_t iterations ) const

inherited

Derive a key from a passphrase for a number of iterations.

Parameters

out	buffer to store the derived key, must be of out_len bytes
out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
iterations	the number of iterations to use (use 10K or more)

Definition at line 78 of file pbkdf.cpp.

                                                      {
   if(iterations == 0) {
      throw Invalid_Argument(name() + ": Invalid iteration count");
   }
 
   const size_t iterations_run =
      pbkdf(out, out_len, passphrase, salt, salt_len, iterations, std::chrono::milliseconds(0));
   BOTAN_ASSERT_EQUAL(iterations, iterations_run, "Expected PBKDF iterations");
}

References BOTAN_ASSERT_EQUAL, name(), and pbkdf().

Referenced by derive_key(), derive_key(), pbkdf(), and pbkdf_iterations().

pbkdf_timed() [1/2]

secure_vector< uint8_t > Botan::PBKDF::pbkdf_timed ( size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, std::chrono::milliseconds msec, size_t & iterations ) const

inherited

Derive a key from a passphrase, running until msec time has elapsed.

Parameters

out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
msec	if iterations is zero, then instead the PBKDF is run until msec milliseconds has passed.
iterations	set to the number iterations executed

Returns

the derived key

Definition at line 100 of file pbkdf.cpp.

                                                                    {
   secure_vector<uint8_t> out(out_len);
   pbkdf_timed(out.data(), out_len, passphrase, salt, salt_len, msec, iterations);
   return out;
}

References pbkdf_timed().

pbkdf_timed() [2/2]

void Botan::PBKDF::pbkdf_timed ( uint8_t out[], size_t out_len, std::string_view passphrase, const uint8_t salt[], size_t salt_len, std::chrono::milliseconds msec, size_t & iterations ) const

inherited

Derive a key from a passphrase, running until msec time has elapsed.

Parameters

out	buffer to store the derived key, must be of out_len bytes
out_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
msec	if iterations is zero, then instead the PBKDF is run until msec milliseconds has passed.
iterations	set to the number iterations executed

Definition at line 68 of file pbkdf.cpp.

                                                  {
   iterations = pbkdf(out, out_len, passphrase, salt, salt_len, 0, msec);
}

References pbkdf().

Referenced by derive_key(), derive_key(), pbkdf(), and pbkdf_timed().

providers()

std::vector< std::string > Botan::PBKDF::providers ( std::string_view algo_spec )

staticinherited

Returns

list of available providers for this algorithm, empty if not available

Definition at line 64 of file pbkdf.cpp.

                                                              {
   return probe_providers_of<PBKDF>(algo_spec);
}

References Botan::probe_providers_of().

---

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