Removing header before decrypting. Continuing to add decryption tests to PDCP NR

lib/include/srslte/upper/pdcp_entity_nr.h

@@ -74,9 +74,9 @@ private:
   uint32_t window_size = 0;
 
   // Packing/Unpacking Helper functions
-  void     write_data_header(const unique_byte_buffer_t& sdu, uint32_t sn);
+  void read_data_header(const unique_byte_buffer_t& sdu, uint32_t* rcvd_sn);
-  void     append_mac(const unique_byte_buffer_t& sdu, uint8_t* mac);
+  void write_data_header(const unique_byte_buffer_t& sdu, uint32_t sn);
-  uint32_t get_rcvd_sn(const unique_byte_buffer_t& pdu);
+  void append_mac(const unique_byte_buffer_t& sdu, uint8_t* mac);
 };
 
 } // namespace srslte

lib/src/upper/pdcp_entity_base.cc

@@ -92,8 +92,8 @@ void pdcp_entity_base::integrity_generate(uint8_t* msg, uint32_t msg_len, uint32
              count,
              cfg.bearer_id,
              (cfg.direction == SECURITY_DIRECTION_DOWNLINK ? "Downlink" : "Uplink"));
+  log->debug_hex(msg, msg_len, "Integrity gen input msg:");
   log->debug_hex(mac, 4, "MAC (generated)");
-  log->debug_hex(msg, msg_len, "  Message");
 }
 
 bool pdcp_entity_base::integrity_verify(uint8_t* msg, uint32_t msg_len, uint32_t count, uint8_t* mac)
@@ -140,7 +140,7 @@ bool pdcp_entity_base::integrity_verify(uint8_t* msg, uint32_t msg_len, uint32_t
              count,
              cfg.bearer_id,
              (cfg.direction == SECURITY_DIRECTION_DOWNLINK ? "Downlink" : "Uplink"));
-  log->debug_hex(msg, msg_len, "  Message");
+  log->debug_hex(msg, msg_len, "Integrity check input msg:");
 
   if (integ_algo != INTEGRITY_ALGORITHM_ID_EIA0) {
     for (uint8_t i = 0; i < 4; i++) {
@@ -175,6 +175,7 @@ void pdcp_entity_base::cipher_encrypt(uint8_t* msg, uint32_t msg_len, uint32_t c
              count,
              cfg.bearer_id,
              (cfg.direction == SECURITY_DIRECTION_DOWNLINK) ? "Downlink" : "Uplink");
+  log->debug_hex(msg, msg_len, "Cipher encrypt input msg");
 
   switch (cipher_algo) {
     case CIPHERING_ALGORITHM_ID_EEA0:
@@ -190,12 +191,14 @@ void pdcp_entity_base::cipher_encrypt(uint8_t* msg, uint32_t msg_len, uint32_t c
     default:
       break;
   }
+  log->debug_hex(ct, msg_len, "Cipher encrypt output msg");
 }
 
 void pdcp_entity_base::cipher_decrypt(uint8_t* ct, uint32_t ct_len, uint32_t count, uint8_t* msg)
 {
   byte_buffer_t msg_tmp;
   uint8_t *k_enc;
+
   // If control plane use RRC encrytion key. If data use user plane key
   if (is_srb()) {
     k_enc = k_rrc_enc;
@@ -203,10 +206,11 @@ void pdcp_entity_base::cipher_decrypt(uint8_t* ct, uint32_t ct_len, uint32_t cou
     k_enc = k_up_enc;
   }
 
-  log->debug("Cipher decript input: COUNT: %d, Bearer ID: %d, Direction %s\n",
+  log->debug("Cipher decrypt input: COUNT: %d, Bearer ID: %d, Direction %s\n",
              count,
              cfg.bearer_id,
              (cfg.direction == SECURITY_DIRECTION_DOWNLINK) ? "Downlink" : "Uplink");
+  log->debug_hex(ct, ct_len, "Cipher decrypt input msg");
 
   switch(cipher_algo)
   {
@@ -237,6 +241,7 @@ void pdcp_entity_base::cipher_decrypt(uint8_t* ct, uint32_t ct_len, uint32_t cou
   default:
     break;
   }
+  log->debug_hex(msg, ct_len,"Cipher decrypt output msg");
 }
 
 }

lib/src/upper/pdcp_entity_nr.cc

@@ -45,6 +45,8 @@ void pdcp_entity_nr::init(srsue::rlc_interface_pdcp* rlc_,
   active        = true;
   do_integrity  = false;
   do_encryption = false;
+
+  window_size = 1 << (cfg.sn_len - 1);
 }
 
 // Reestablishment procedure: 38.323 5.2
@@ -107,18 +109,27 @@ void pdcp_entity_nr::write_pdu(unique_byte_buffer_t pdu)
     return;
   }
 
+  // Extract RCVD_SN from header
+  uint32_t rcvd_sn;
+  read_data_header(pdu, &rcvd_sn);
+
   // Calculate RCVD_COUNT
-  uint32_t rcvd_sn = get_rcvd_sn(pdu);
+  printf("%d\n", rcvd_sn);
   uint32_t rcvd_hfn, rcvd_count;
-  if (rcvd_sn < SN(rx_deliv) - window_size) {
+  if ((int64_t)rcvd_sn < (int64_t)SN(rx_deliv) - (int64_t)window_size) {
+    printf("rcvd_sn %d < SN(rx_deliv) %d(%d) - window_size %d\n", rcvd_sn, SN(rx_deliv), rx_deliv, window_size);
     rcvd_hfn = HFN(rx_deliv) + 1;
   } else if (rcvd_sn >= SN(rx_deliv) + window_size) {
+    printf("rcvd_sn %d >= SN(rx_deliv) %d(%d) + window_size %d\n", rcvd_sn, SN(rx_deliv), rx_deliv, window_size);
     rcvd_hfn = HFN(rx_deliv) - 1;
   } else {
     rcvd_hfn = HFN(rx_deliv);
   }
   rcvd_count = COUNT(rcvd_hfn, rcvd_sn);
 
+  // Decripting
+  cipher_decrypt(pdu->msg, pdu->N_bytes - 4, rcvd_count, pdu->msg);
+
   // Integrity check
   uint8_t mac[4];
   bool is_valid = integrity_verify(pdu->msg, pdu->N_bytes, rcvd_count, mac);
@@ -126,8 +137,6 @@ void pdcp_entity_nr::write_pdu(unique_byte_buffer_t pdu)
     return; // Invalid packet, drop.
   }
 
-  // Decripting
-  cipher_decrypt(pdu->msg, pdu->N_bytes, rcvd_count, pdu->msg);
 
   // Check valid rcvd_count
   if (rcvd_count < rx_deliv /*|| check_received_before() TODO*/) {
@@ -154,20 +163,23 @@ void pdcp_entity_nr::write_pdu(unique_byte_buffer_t pdu)
   // TODO handle reordering timers
 }
 
-uint32_t pdcp_entity_nr::get_rcvd_sn(const unique_byte_buffer_t& pdu)
+void pdcp_entity_nr::read_data_header(const unique_byte_buffer_t& pdu, uint32_t *rcvd_sn)
 {
-  uint32_t rcvd_sn = 0;
+  uint16_t rcvd_sn_16 = 0;
   switch (cfg.sn_len) {
     case PDCP_SN_LEN_12:
-      pdu->msg;
+      srslte::uint8_to_uint16(pdu->msg, &rcvd_sn_16);
+      (*rcvd_sn) = 0x0FFF & rcvd_sn_16;
       break;
     case PDCP_SN_LEN_18:
-      pdu->msg;
+      // srslte::uint8_to_uint24((uint16_t*)sdu->msg, rcvd_sn);
       break;
     default:
       log->error("Cannot extract RCVD_SN, invalid SN length configured: %d\n", cfg.sn_len);
   }
-  return rcvd_sn;
+  pdu->msg += cfg.hdr_len_bytes;
+  pdu->N_bytes -= cfg.hdr_len_bytes;
+  return;
 }
 
 void pdcp_entity_nr::write_data_header(const srslte::unique_byte_buffer_t& sdu, uint32_t count)