ffi_srp6.cpp File Reference

#include <botan/ffi.h>
#include <botan/assert.h>
#include <botan/internal/ffi_rng.h>
#include <botan/internal/ffi_util.h>

Go to the source code of this file.

Functions
	BOTAN_FFI_DECLARE_DUMMY_STRUCT (botan_srp6_server_session_struct, 0x44F7425F)
int	botan_srp6_client_agree (const char *identity, const char *password, const char *group_id, const char *hash_id, const uint8_t salt[], size_t salt_len, const uint8_t b[], size_t b_len, botan_rng_t rng_obj, uint8_t A[], size_t *A_len, uint8_t K[], size_t *K_len)
int	botan_srp6_generate_verifier (const char *username, const char *password, const uint8_t salt[], size_t salt_len, const char *group_id, const char *hash_id, uint8_t verifier[], size_t *verifier_len)
int	botan_srp6_group_size (const char *group_id, size_t *group_p_bytes)
int	botan_srp6_server_session_destroy (botan_srp6_server_session_t srp6)
int	botan_srp6_server_session_init (botan_srp6_server_session_t *srp6)
int	botan_srp6_server_session_step1 (botan_srp6_server_session_t srp6, const uint8_t *verifier, size_t verifier_len, const char *group_id, const char *hash_id, botan_rng_t rng_obj, uint8_t b_pub[], size_t *b_pub_len)
int	botan_srp6_server_session_step2 (botan_srp6_server_session_t srp6, const uint8_t a[], size_t a_len, uint8_t key[], size_t *key_len)

Function Documentation

BOTAN_FFI_DECLARE_DUMMY_STRUCT()

BOTAN_FFI_DECLARE_DUMMY_STRUCT	(	botan_srp6_server_session_struct	,
		0x44F7425F	)

botan_srp6_client_agree()

int botan_srp6_client_agree	(	const char *	username,
		const char *	password,
		const char *	group_id,
		const char *	hash_id,
		const uint8_t	salt[],
		size_t	salt_len,
		const uint8_t	B[],
		size_t	B_len,
		botan_rng_t	rng_obj,
		uint8_t	A[],
		size_t *	A_len,
		uint8_t	K[],
		size_t *	K_len )

SRP6a Client side

Parameters

username	the username we are attempting login for
password	the password we are attempting to use
group_id	specifies the shared SRP group
hash_id	specifies a secure hash function
salt	is the salt value sent by the server
salt_len	the length of salt
B	is the server's public value
B_len	is the server's public value length
rng_obj	is a random number generator object
A	out buffer to store the SRP-6 A value
A_len	SRP-6 A verifier value length
K	out buffer to store the symmetric value
K_len	symmetric key length

Returns

0 on success, negative on failure

Definition at line 150 of file ffi_srp6.cpp.

                                           {
#if defined(BOTAN_HAS_SRP6)
   return ffi_guard_thunk(__func__, [=]() -> int {
      if(any_null_pointers(identity, password, salt, group_id, hash_id, b, rng_obj)) {
         return BOTAN_FFI_ERROR_NULL_POINTER;
      }
      try {
         const std::vector<uint8_t> saltv(salt, salt + salt_len);
         Botan::RandomNumberGenerator& rng = safe_get(rng_obj);
         auto b_bn = Botan::BigInt::from_bytes({b, b_len});
         const auto group = Botan::DL_Group::from_name(group_id);
         const size_t a_bits = group.exponent_bits();
         auto [A_bn, K_sk] = Botan::srp6_client_agree(identity, password, group, hash_id, saltv, b_bn, a_bits, rng);
         auto ret_a = write_vec_output(A, A_len, A_bn.serialize(group.p_bytes()));
         auto ret_k = write_vec_output(K, K_len, K_sk.bits_of());
         if(ret_a != BOTAN_FFI_SUCCESS) {
            return ret_a;
         }
         if(ret_k != BOTAN_FFI_SUCCESS) {
            return ret_k;
         }
         return BOTAN_FFI_SUCCESS;
      } catch(Botan::Lookup_Error&) {
         return BOTAN_FFI_ERROR_BAD_PARAMETER;
      }
   });
#else
   BOTAN_UNUSED(identity, password, group_id, hash_id, rng_obj);
   BOTAN_UNUSED(salt, salt_len, b, b_len, A, A_len, K, K_len);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References Botan_FFI::any_null_pointers(), BOTAN_FFI_ERROR_BAD_PARAMETER, BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FFI_SUCCESS, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), Botan::BigInt::from_bytes(), Botan::DL_Group::from_name(), Botan_FFI::safe_get(), Botan::srp6_client_agree(), and Botan_FFI::write_vec_output().

Referenced by botan_srp6_server_session_step1().

botan_srp6_generate_verifier()

int botan_srp6_generate_verifier	(	const char *	identifier,
		const char *	password,
		const uint8_t	salt[],
		size_t	salt_len,
		const char *	group_id,
		const char *	hash_id,
		uint8_t	verifier[],
		size_t *	verifier_len )

Generate a new SRP-6 verifier

Parameters

identifier	a username or other client identifier
password	the secret used to authenticate user
salt	a randomly chosen value, at least 128 bits long
salt_len	the length of salt
group_id	specifies the shared SRP group
hash_id	specifies a secure hash function
verifier	out buffer to store the SRP-6 verifier value
verifier_len	SRP-6 verifier value length

Returns

0 on success, negative on failure

Definition at line 120 of file ffi_srp6.cpp.

                                                       {
#if defined(BOTAN_HAS_SRP6)
   return ffi_guard_thunk(__func__, [=]() -> int {
      if(any_null_pointers(username, password, salt, group_id, hash_id)) {
         return BOTAN_FFI_ERROR_NULL_POINTER;
      }
      try {
         const std::vector<uint8_t> salt_vec(salt, salt + salt_len);
         const auto group = Botan::DL_Group::from_name(group_id);
         const size_t p_bytes = group.p_bytes();
         auto verifier_bn = Botan::srp6_generate_verifier(username, password, salt_vec, group, hash_id);
         return write_vec_output(verifier, verifier_len, verifier_bn.serialize(p_bytes));
      } catch(Botan::Lookup_Error&) {
         return BOTAN_FFI_ERROR_BAD_PARAMETER;
      }
   });
#else
   BOTAN_UNUSED(username, password, group_id, hash_id);
   BOTAN_UNUSED(salt, salt_len, verifier, verifier_len);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References Botan_FFI::any_null_pointers(), BOTAN_FFI_ERROR_BAD_PARAMETER, BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), Botan::DL_Group::from_name(), Botan::srp6_generate_verifier(), and Botan_FFI::write_vec_output().

Referenced by botan_srp6_server_session_step1().

botan_srp6_group_size()

int botan_srp6_group_size	(	const char *	group_id,
		size_t *	group_p_bytes )

Return the size, in bytes, of the prime associated with group_id

Definition at line 46 of file ffi_srp6.cpp.

                                                                       {
#if defined(BOTAN_HAS_SRP6)
   if(any_null_pointers(group_id, group_p_bytes)) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }
 
   return ffi_guard_thunk(__func__, [=]() -> int {
      const auto group = Botan::DL_Group::from_name(group_id);
      *group_p_bytes = group.p_bytes();
      return BOTAN_FFI_SUCCESS;
   });
#else
   BOTAN_UNUSED(group_id, group_p_bytes);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References Botan_FFI::any_null_pointers(), BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FFI_SUCCESS, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), and Botan::DL_Group::from_name().

Referenced by botan_srp6_server_session_step1().

botan_srp6_server_session_destroy()

int botan_srp6_server_session_destroy

(

botan_srp6_server_session_t

srp6

)

Frees all resources of the SRP-6 server session object

Parameters

srp6	SRP-6 server session object

Returns

0 if success, error if invalid object handle

Definition at line 42 of file ffi_srp6.cpp.

                                                                        {
   return BOTAN_FFI_CHECKED_DELETE(srp6);
}

References BOTAN_FFI_CHECKED_DELETE.

botan_srp6_server_session_init()

int botan_srp6_server_session_init

(

botan_srp6_server_session_t *

srp6

)

Initialize an SRP-6 server session object

Parameters

srp6	SRP-6 server session object

Definition at line 32 of file ffi_srp6.cpp.

                                                                      {
#if defined(BOTAN_HAS_SRP6)
   return ffi_guard_thunk(
      __func__, [=]() -> int { return ffi_new_object(srp6, std::make_unique<Botan::SRP6_Server_Session>()); });
#else
   BOTAN_UNUSED(srp6);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), and Botan_FFI::ffi_new_object().

botan_srp6_server_session_step1()

int botan_srp6_server_session_step1	(	botan_srp6_server_session_t	srp6,
		const uint8_t *	verifier,
		size_t	verifier_len,
		const char *	group_id,
		const char *	hash_id,
		botan_rng_t	rng_obj,
		uint8_t	b_pub[],
		size_t *	b_pub_len )

Definition at line 63 of file ffi_srp6.cpp.

                                                       {
#if defined(BOTAN_HAS_SRP6)
   return BOTAN_FFI_VISIT(srp6, [=](auto& s) -> int {
      if(any_null_pointers(verifier, group_id, hash_id, rng_obj)) {
         return BOTAN_FFI_ERROR_NULL_POINTER;
      }
      try {
         const auto group = Botan::DL_Group::from_name(group_id);
         const auto rc = check_and_prepare_output_space(b_pub, b_pub_len, group.p_bytes());
         if(rc != BOTAN_FFI_SUCCESS) {
            return rc;
         }
 
         Botan::RandomNumberGenerator& rng = safe_get(rng_obj);
         auto v_bn = Botan::BigInt::from_bytes(std::span{verifier, verifier_len});
         auto b_pub_bn = s.step1(v_bn, group, hash_id, group.exponent_bits(), rng);
         return write_vec_output(b_pub, b_pub_len, b_pub_bn.serialize(group.p_bytes()));
      } catch(Botan::Decoding_Error&) {
         return BOTAN_FFI_ERROR_BAD_PARAMETER;
      } catch(Botan::Lookup_Error&) {
         return BOTAN_FFI_ERROR_BAD_PARAMETER;
      }
   });
#else
   BOTAN_UNUSED(srp6, verifier, verifier_len, group_id, hash_id, rng_obj, b_pub, b_pub_len);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References Botan_FFI::any_null_pointers(), BOTAN_FFI_ERROR_BAD_PARAMETER, BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FFI_SUCCESS, BOTAN_FFI_VISIT, BOTAN_UNUSED, Botan_FFI::check_and_prepare_output_space(), Botan::BigInt::from_bytes(), Botan::DL_Group::from_name(), Botan_FFI::safe_get(), and Botan_FFI::write_vec_output().

botan_srp6_server_session_step2()

int botan_srp6_server_session_step2	(	botan_srp6_server_session_t	srp6,
		const uint8_t	A[],
		size_t	A_len,
		uint8_t	key[],
		size_t *	key_len )

SRP-6 Server side step 2

Parameters

srp6	SRP-6 server session object
A	the client's value
A_len	the client's value length
key	out buffer to store the symmetric key value
key_len	symmetric key length

Returns

0 on success, negative on failure

Definition at line 99 of file ffi_srp6.cpp.

                                                                                                      {
#if defined(BOTAN_HAS_SRP6)
   return BOTAN_FFI_VISIT(srp6, [=](auto& s) -> int {
      if(!a) {
         return BOTAN_FFI_ERROR_NULL_POINTER;
      }
      try {
         const Botan::BigInt a_bn = Botan::BigInt::from_bytes({a, a_len});
         auto key_sk = s.step2(a_bn);
         return write_vec_output(key, key_len, key_sk.bits_of());
      } catch(Botan::Decoding_Error&) {
         return BOTAN_FFI_ERROR_BAD_PARAMETER;
      }
   });
#else
   BOTAN_UNUSED(srp6, a, a_len, key, key_len);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References BOTAN_FFI_ERROR_BAD_PARAMETER, BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FFI_VISIT, BOTAN_UNUSED, Botan::BigInt::from_bytes(), and Botan_FFI::write_vec_output().

Referenced by botan_srp6_server_session_step1().