Botan::SRP6_Server_Session Class Reference

#include <srp6.h>

Public Member Functions
BigInt	step1 (const BigInt &v, const std::string &group_id, const std::string &hash_id, RandomNumberGenerator &rng)
BigInt	step1 (const BigInt &v, const DL_Group &group, const std::string &hash_id, const size_t b_bits, RandomNumberGenerator &rng)
SymmetricKey	step2 (const BigInt &A)

Detailed Description

Represents a SRP-6a server session

Definition at line 107 of file srp6.h.

Member Function Documentation

BigInt Botan::SRP6_Server_Session::step1	(	const BigInt &	v,
		const std::string &	group_id,
		const std::string &	hash_id,
		RandomNumberGenerator &	rng
	)

Server side step 1

Parameters

v	the verification value saved from client registration
group_id	the SRP group id
hash_id	the SRP hash in use
rng	a random number generator

Returns

SRP-6 B value

Definition at line 148 of file srp6.cpp.

References Botan::DL_Group::exponent_bits().

   {
   DL_Group group(group_id);
   const size_t b_bits = group.exponent_bits();

   return this->step1(v, group, hash_id, b_bits, rng);
   }

BigInt Botan::SRP6_Server_Session::step1	(	const BigInt &	v,
		const DL_Group &	group,
		const std::string &	hash_id,
		const size_t	b_bits,
		RandomNumberGenerator &	rng
	)

Server side step 1 This version of step1 added in 2.11

Parameters

v	the verification value saved from client registration
group	the SRP group
hash_id	the SRP hash in use
rng	a random number generator
b_bits	size of secret exponent in bits

Returns

SRP-6 B value

Definition at line 159 of file srp6.cpp.

References Botan::BigInt::bytes(), Botan::DL_Group::get_g(), Botan::DL_Group::get_p(), Botan::DL_Group::mod_p(), and Botan::DL_Group::power_g_p().

   {
   const BigInt& g = group.get_g();
   const BigInt& p = group.get_p();

   m_p_bytes = p.bytes();
   m_v = v;
   m_b = BigInt(rng, b_bits);
   m_p = p;
   m_hash_id = hash_id;

   const BigInt k = hash_seq(hash_id, m_p_bytes, p, g);

   m_B = group.mod_p(v*k + group.power_g_p(m_b, b_bits));

   return m_B;
   }

SymmetricKey Botan::SRP6_Server_Session::step2

(

const BigInt &

A

)

Server side step 2

Parameters

A	the client's value

Returns

shared symmetric key

Definition at line 181 of file srp6.cpp.

References Botan::BigInt::encode_1363(), and Botan::power_mod().

Referenced by Botan::TLS::Client_Key_Exchange::Client_Key_Exchange().

   {
   if(A <= 0 || A >= m_p)
      throw Decoding_Error("Invalid SRP parameter from client");

   const BigInt u = hash_seq(m_hash_id, m_p_bytes, A, m_B);

   const BigInt S = power_mod(A * power_mod(m_v, u, m_p), m_b, m_p);

   return BigInt::encode_1363(S, m_p_bytes);
   }

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

• src/lib/misc/srp6/srp6.h
• src/lib/misc/srp6/srp6.cpp