Botan::PKCS12_KDF Class Reference

#include <pkcs12_kdf.h>

Inheritance diagram for Botan::PKCS12_KDF:

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
	PKCS12_KDF (std::unique_ptr< HashFunction > hash, uint8_t id, 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

PKCS#12 KDF (RFC 7292 Appendix B)

The id parameter (purpose byte) is fixed at family construction time: 1 = encryption key, 2 = IV, 3 = MAC key

The family spec used with PasswordHashFamily::create() is "PKCS12-KDF(hash,id)", e.g. "PKCS12-KDF(SHA-1,1)" with two arguments. PKCS12_KDF::to_string() additionally embeds the iteration count for round-tripping a fully-parameterized instance, producing "PKCS12-KDF(hash,id,iterations)"; that 3-argument form is not accepted by PasswordHashFamily::create() and should not be used as an algo spec.

Definition at line 35 of file pkcs12_kdf.h.

Constructor & Destructor Documentation

PKCS12_KDF()

Botan::PKCS12_KDF::PKCS12_KDF	(	std::unique_ptr< HashFunction >	hash,
		uint8_t	id,
		size_t	iterations )

Definition at line 166 of file pkcs12_kdf.cpp.

                                                                                      :
      m_hash(std::move(hash)), m_id(id), m_iterations(iterations) {
   BOTAN_ARG_CHECK(m_hash != nullptr, "PKCS12-KDF: hash must not be null");
   BOTAN_ARG_CHECK(m_iterations > 0, "PKCS12-KDF: iterations must be greater than zero");
   BOTAN_ARG_CHECK(m_id >= 1 && m_id <= 3, "PKCS12-KDF: id must be 1 (key), 2 (IV), or 3 (MAC)");
}

References BOTAN_ARG_CHECK, Botan::PasswordHash::hash(), and iterations().

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

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
ad	some additional data
ad_len	length of ad in bytes
key	a secret key
key_len	length 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 39 of file pwdhash.cpp.

                                                    {
   BOTAN_UNUSED(ad, key);
 
   if(ad_len == 0 && key_len == 0) {
      return this->derive_key(out, out_len, password, password_len, salt, salt_len);
   } else {
      throw Not_Implemented("PasswordHash " + this->to_string() + " does not support AD or key");
   }
}

References BOTAN_UNUSED, derive_key(), and to_string().

derive_key() [2/2]

void Botan::PKCS12_KDF::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 177 of file pkcs12_kdf.cpp.

                                                   {
   const std::string_view pwd =
      (password != nullptr && password_len > 0) ? std::string_view(password, password_len) : std::string_view{};
   pkcs12_kdf_with_hash({out, out_len}, pkcs12_encode_password(pwd), {salt, salt_len}, m_iterations, m_id, *m_hash);
}

Referenced by Botan::PKCS12::export_to().

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

out	a span where the derived key will be placed
password	the password to derive the key from
salt	a 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 95 of file pwdhash.h.

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

References derive_key().

Referenced by Botan::PKCS12_KDF::PKCS12_KDF(), and Botan::RFC4880_S2K::RFC4880_S2K().

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

out	a span where the derived key will be placed
password	the password to derive the key from
salt	a randomly chosen salt
associated_data	some additional data
key	a 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 116 of file pwdhash.h.

                                                  {
         this->derive_key(out.data(),
                          out.size(),
                          password.data(),
                          password.size(),
                          salt.data(),
                          salt.size(),
                          associated_data.data(),
                          associated_data.size(),
                          key.data(),
                          key.size());
      }

References derive_key().

iterations()

size_t Botan::PKCS12_KDF::iterations ( ) const

inlineoverridevirtual

Most password hashes have some notion of iterations.

Implements Botan::PasswordHash.

Definition at line 41 of file pkcs12_kdf.h.

{ return m_iterations; }

Referenced by PKCS12_KDF().

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 47 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::Bcrypt_PBKDF, and Botan::Scrypt.

Definition at line 57 of file pwdhash.h.

{ return 0; }

supports_associated_data()

virtual bool Botan::PasswordHash::supports_associated_data ( ) const

inlinevirtualinherited

Query if this password hash supports associated data

Returns

true if this password hash supports supplying associated data

Reimplemented in Botan::Argon2.

Definition at line 80 of file pwdhash.h.

{ return false; }

supports_keyed_operation()

virtual bool Botan::PasswordHash::supports_keyed_operation ( ) const

inlinevirtualinherited

Query if this password hash supports a symmetric key

Returns

true if this password hash supports supplying a key

Reimplemented in Botan::Argon2.

Definition at line 73 of file pwdhash.h.

{ return false; }

to_string()

std::string Botan::PKCS12_KDF::to_string ( ) const

overridevirtual

Return a free-form string identifying the algorithm and parameters

Implements Botan::PasswordHash.

Definition at line 173 of file pkcs12_kdf.cpp.

                                      {
   return fmt("PKCS12-KDF({},{},{})", m_hash->name(), static_cast<unsigned>(m_id), m_iterations);
}

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 66 of file pwdhash.h.

{ return 0; }

---

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

• src/lib/pbkdf/pkcs12_kdf/pkcs12_kdf.h
• src/lib/pbkdf/pkcs12_kdf/pkcs12_kdf.cpp