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This commit is contained in:
cesaaargm 2023-12-17 14:15:00 +01:00
parent efbb3e0cbf
commit 7f3202be8e
2 changed files with 16 additions and 6 deletions
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19
src/core/libs/osnma_msg_receiver.cc
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@ -150,7 +150,9 @@ void osnma_msg_receiver::read_dsm_header(uint8_t dsm_header)
<< std::endl; << std::endl;
} }
/*
* accumulates dsm messages until completeness, then calls process_dsm_message
* */
void osnma_msg_receiver::read_dsm_block(const std::shared_ptr<OSNMA_msg>& osnma_msg) void osnma_msg_receiver::read_dsm_block(const std::shared_ptr<OSNMA_msg>& osnma_msg)
{ {
size_t index = 0; size_t index = 0;
@ -245,7 +247,13 @@ void osnma_msg_receiver::read_dsm_block(const std::shared_ptr<OSNMA_msg>& osnma_
} }
} }
/*
* case DSM-Kroot:
* - computes the padding
* - if successful, tries to verify the digital signature
* case DSM-PKR:
* - calls verify_dsm_pkr to verify the public key
* */
void osnma_msg_receiver::process_dsm_message(const std::vector<uint8_t>& dsm_msg, const std::shared_ptr<OSNMA_msg>& osnma_msg) void osnma_msg_receiver::process_dsm_message(const std::vector<uint8_t>& dsm_msg, const std::shared_ptr<OSNMA_msg>& osnma_msg)
{ {
if (d_osnma_data.d_dsm_header.dsm_id < 12) if (d_osnma_data.d_dsm_header.dsm_id < 12)
@ -441,8 +449,9 @@ void osnma_msg_receiver::read_mack_block(const std::shared_ptr<OSNMA_msg>& osnma
index = index + 4; index = index + 4;
} }
// compute time of subrame and kroot time of applicability, used in read_mack_body and process_mack_message // compute time of subrame and kroot time of applicability, used in read_mack_body and process_mack_message
d_GST_Sf = osnma_msg->TOW_sf0 + osnma_msg->WN_sf0 * 604800; // TODO - find a better placement d_GST_SIS = osnma_msg->TOW_sf0 + osnma_msg->WN_sf0 * 604800; // TODO - find a better placement
d_GST_0 = d_osnma_data.d_dsm_kroot_message.towh_k + 604800 * d_osnma_data.d_dsm_kroot_message.wn_k; d_GST_0 = d_osnma_data.d_dsm_kroot_message.towh_k + 604800 * d_osnma_data.d_dsm_kroot_message.wn_k;
d_GST_Sf = d_GST_0 + 30 * std::floor((d_GST_SIS-d_GST_0)/30); // TODO - find a better placement
if (d_osnma_data.d_dsm_kroot_message.ts != 0) // C: 4 ts < ts < 10 if (d_osnma_data.d_dsm_kroot_message.ts != 0) // C: 4 ts < ts < 10
{ {
read_mack_header(); read_mack_header();
@ -703,11 +712,11 @@ void osnma_msg_receiver::read_mack_body()
std::vector<uint8_t> K_II = d_osnma_data.d_mack_message.key; std::vector<uint8_t> K_II = d_osnma_data.d_mack_message.key;
std::vector<uint8_t> K_I; // result of the recursive hash operations std::vector<uint8_t> K_I; // result of the recursive hash operations
uint8_t size_hash_f = d_osnma_data.d_dsm_kroot_message.ks / 8; uint8_t size_hash_f = d_osnma_data.d_dsm_kroot_message.ks / 8;
// compute the current tesla key // compute the current tesla key , GST_SFi and K_II change in each iteration
for (uint8_t i = 1; i < num_of_hashes_needed ; i++) for (uint8_t i = 1; i < num_of_hashes_needed ; i++)
{ {
// build message digest m = (K_I+1 || GST_SFi || alpha) // build message digest m = (K_I+1 || GST_SFi || alpha)
std::vector<uint8_t> msg(sizeof(K_II) + sizeof(d_GST_Sf) + sizeof(d_osnma_data.d_dsm_kroot_message.alpha)); std::vector<uint8_t> msg(sizeof(K_II) + sizeof(GST_SFi) + sizeof(d_osnma_data.d_dsm_kroot_message.alpha));
std::copy(K_II.begin(),K_II.end(),msg.begin()); std::copy(K_II.begin(),K_II.end(),msg.begin());
msg.push_back((d_GST_Sf & 0xF000) >> 24); msg.push_back((d_GST_Sf & 0xF000) >> 24);

1
src/core/libs/osnma_msg_receiver.h
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@ -86,6 +86,7 @@ private:
bool d_kroot_verified{false}; bool d_kroot_verified{false};
uint32_t d_GST_Sf {}; // C: used for MACSEQ and Tesla Key verification uint32_t d_GST_Sf {}; // C: used for MACSEQ and Tesla Key verification
uint32_t d_GST_0 {}; uint32_t d_GST_0 {};
uint32_t d_GST_SIS {};
}; };