implemented client-server connection, but found out RSA is broken

.vscode/launch.json

@@ -7,6 +7,7 @@
             "request": "launch",
             "program": "${workspaceFolder}/bin/tcp-chat",
             "windows": { "program": "${workspaceFolder}/bin/tcp-chat.exe" },
+            "args": [ "-l", "127.0.0.1:9988" ],
             "preLaunchTask": "build_exec_dbg",
             "stopAtEntry": false,
             "cwd": "${workspaceFolder}/bin",

dependencies/tlibc

@@ -1 +1 @@
-Subproject commit 75c94e88d9a7e12839d343bf4c7978cb7ecf91e1
+Subproject commit 5fb2db2380b678381ef455a18c8210a6a3314e60

src/client/ClientCredential.c

@@ -1,7 +1,7 @@
 #include "client.h"
 #include "tlibc/string/StringBuilder.h"
 
-void ClientCredential_free(ClientCredential* cred){
+void ClientCredentials_free(ClientCredentials* cred){
     if(cred == NULL)
         return;
     free(cred->username.data);
@@ -10,10 +10,10 @@ void ClientCredential_free(ClientCredential* cred){
 }
 
 
-Result(ClientCredential*) ClientCredential_create(str username, str password){
+Result(ClientCredentials*) ClientCredentials_create(str username, str password){
     Deferral(8);
-    ClientCredential* cred = (ClientCredential*)malloc(sizeof(ClientCredential));
+    ClientCredentials* cred = (ClientCredentials*)malloc(sizeof(ClientCredentials));
-    memset(cred, 0, sizeof(ClientCredential));
+    memset(cred, 0, sizeof(ClientCredentials));
     bool success = false;
     Defer(
         if(!success)

src/client/ServerConnection.c

@@ -5,8 +5,7 @@ void ServerConnection_close(ServerConnection* conn){
     if(conn == NULL)
         return;
     RSA_destroyPublicKey(&conn->server_pk);
-    socket_close(conn->system_socket.sock);
+    socket_close(conn->sock.sock);
-    socket_close(conn->content_socket.sock);
     free(conn->session_key.data);
     free(conn);
 }
@@ -17,10 +16,9 @@ void ServerConnection_close(ServerConnection* conn){
 Result(void) ServerLink_parse(cstr server_link_cstr, EndpointIPv4* server_end_out, br_rsa_public_key* server_key_out){
     Deferral(8);
     str server_link_str = str_from_cstr(server_link_cstr);
-    i32 sep_pos = 0;
     
     // parse address and port
-    sep_pos = str_seekChar(server_link_str, ':', sep_pos);
+    i32 sep_pos = str_seekChar(server_link_str, ':', 0);
     if(sep_pos == -1){
         Return RESULT_ERROR_FMT("server link is invalid: %s", server_link_cstr);
     }
@@ -31,22 +29,21 @@ Result(void) ServerLink_parse(cstr server_link_cstr, EndpointIPv4* server_end_ou
     }
 
     // parse public key
-    sep_pos = str_seekChar(server_link_str, ':', sep_pos);
+    sep_pos = str_seekChar(server_link_str, ':', sep_pos + 1);
     if(sep_pos == -1){
         Return RESULT_ERROR_FMT("server link is invalid: %s", server_link_cstr);
     }
-    str server_key_str = server_link_str;
+    str server_key_str = str_sliceAfter(server_link_str, sep_pos + 1);
-    server_key_str.data += sep_pos + 1;
     try_void(RSA_parsePublicKey_base64(server_key_str, server_key_out));
     
     Return RESULT_VOID;
 }
 
-Result(ServerConnection*) ServerConnection_open(ClientCredential* client_credential, cstr server_link_cstr){
+Result(ServerConnection*) ServerConnection_open(ClientCredentials* client_credentials, cstr server_link_cstr){
     Deferral(64);
 
     ServerConnection* conn = (ServerConnection*)malloc(sizeof(ServerConnection));
-    memset(conn, 0, sizeof(ServerConnection));
+    memset(conn, 0, sizeof(*conn));
     bool success = false;
     Defer(
         if(!success)
@@ -57,6 +54,7 @@ Result(ServerConnection*) ServerConnection_open(ClientCredential* client_credent
     RSAEncryptor_construct(&conn->rsa_enc, &conn->server_pk);
     
     conn->session_key = Array_alloc_size(AES_SESSION_KEY_SIZE);
+    // generate random session key
     br_hmac_drbg_context key_rng = { .vtable = &br_hmac_drbg_vtable };
     rng_init_sha256_seedFromSystem(&key_rng.vtable);
     br_hmac_drbg_generate(&key_rng, conn->session_key.data, conn->session_key.size);
@@ -64,73 +62,85 @@ Result(ServerConnection*) ServerConnection_open(ClientCredential* client_credent
     // connect to server address
     Socket _s;
     try(_s, i, socket_open_TCP());
-    EncryptedSocketTCP_construct(&conn->system_socket, _s, conn->session_key);
+    try_void(socket_connect(_s, conn->server_end));
-    try_void(socket_connect(conn->system_socket.sock, conn->server_end));
+    EncryptedSocketTCP_construct(&conn->sock, _s, conn->session_key);
     
-    Array(u8) encrypted_buf = Array_alloc_size(8*1024);
+    Array(u8) enc_buf = Array_alloc_size(8*1024);
-    Defer(free(encrypted_buf.data));
+    Defer(free(enc_buf.data));
-    Array(u8) decrypted_buf = Array_alloc_size(8*1024);
+    Array(u8) dec_buf = Array_alloc_size(8*1024);
-    Defer(free(decrypted_buf.data));
+    Defer(free(dec_buf.data));
-    u32 encrypted_size = 0, decrypted_size = 0;
+    u32 enc_size = 0, dec_size = 0;
 
-    // send handshake to the server
+    // construct ClientHandshake in dec_buf
-    ClientHandshake client_handshake;
+    try_void(ClientHandshake_tryConstruct((ClientHandshake*)dec_buf.data, conn->session_key));
-    try_void(ClientHandshake_tryConstruct(&client_handshake, conn->session_key));
+    // encrypt by server public key
-    // encryption by server public key
+    try(enc_size, u, 
-    try(encrypted_size, u, RSAEncryptor_encrypt(&conn->rsa_enc, 
+        RSAEncryptor_encrypt(
-        struct_castTo_Array(&client_handshake), 
+            &conn->rsa_enc, 
-        encrypted_buf));
+            Array_sliceBefore(dec_buf, sizeof(ClientHandshake)), 
-    try_void(socket_send(conn->system_socket.sock, 
+            enc_buf
-        Array_construct_size(encrypted_buf.data, encrypted_size)));
+        )
+    );
+    try_void(socket_send(conn->sock.sock, Array_sliceBefore(enc_buf, enc_size)));
     
     // receive server response
-    encrypted_size = AESStreamEncryptor_calcDstSize(sizeof(PacketHeader));
+    enc_size = AESStreamEncryptor_calcDstSize(sizeof(PacketHeader));
-    try(decrypted_size, u, EncryptedSocketTCP_recv(&conn->system_socket,
+    try(dec_size, u, 
-        Array_construct_size(encrypted_buf.data, encrypted_size),
+        EncryptedSocketTCP_recv(&conn->sock,
-        decrypted_buf,
+            Array_sliceBefore(enc_buf, enc_size),
-        SocketRecvFlag_WaitAll));
+            dec_buf,
-    try_assert(decrypted_size == sizeof(PacketHeader));
+            SocketRecvFlag_WaitAll
-    PacketHeader* packet_header = decrypted_buf.data;
+        )
+    );
+    try_assert(dec_size == sizeof(PacketHeader));
+    PacketHeader* packet_header = dec_buf.data;
     try_void(PacketHeader_validateMagic(packet_header));
     
+    // handle server response
     switch(packet_header->type){
-        case PacketType_ErrorMessage:
+        case PacketType_ErrorMessage: {
             Array(u8) err_buf = Array_alloc_size(packet_header->content_size + 1);
             bool err_msg_completed = false;
             Defer(
                 if(!err_msg_completed)
                     free(err_buf.data);
             );
-            encrypted_size = AESStreamEncryptor_calcDstSize(packet_header->content_size);
+
-            if(encrypted_size > encrypted_buf.size)
+            // receive error message of length packet_header->content_size
-                encrypted_size = encrypted_buf.size;
+            enc_size = AESStreamEncryptor_calcDstSize(packet_header->content_size);
-            try_void(EncryptedSocketTCP_recv(&conn->system_socket,
+            if(enc_size > enc_buf.size)
-                Array_construct_size(encrypted_buf.data, encrypted_size),
+                enc_size = enc_buf.size;
+            try_void(
+                EncryptedSocketTCP_recv(
+                    &conn->sock,
+                    Array_sliceBefore(enc_buf, enc_size),
                     err_buf,
-                SocketRecvFlag_WaitAll));
+                    SocketRecvFlag_WaitAll
-            ((u8*)err_buf.data)[encrypted_size] = 0;
+                )
+            );
+
+            ((u8*)err_buf.data)[enc_size] = 0;
             err_msg_completed = true;
             Return RESULT_ERROR((char*)err_buf.data, true);
-        case PacketType_ServerHandshake:
+        }
-            encrypted_size = AESStreamEncryptor_calcDstSize(sizeof(ServerHandshake) - sizeof(PacketHeader));
+        case PacketType_ServerHandshake: {
-            try_void(EncryptedSocketTCP_recv(&conn->system_socket,
+            enc_size = AESStreamEncryptor_calcDstSize(sizeof(ServerHandshake) - sizeof(PacketHeader));
-                Array_construct_size(encrypted_buf.data, encrypted_size),
+            try_void(
-                Array_construct_size((u8*)decrypted_buf.data + sizeof(PacketHeader), decrypted_buf.size - sizeof(PacketHeader)),
+                EncryptedSocketTCP_recv(
+                    &conn->sock,
+                    Array_sliceBefore(enc_buf, enc_size),
+                    Array_sliceAfter(dec_buf, sizeof(PacketHeader)),
                     SocketRecvFlag_WaitAll
-            ));
+                )
-            ServerHandshake* server_handshake = decrypted_buf.data;
+            );
+            ServerHandshake* server_handshake = dec_buf.data;
             conn->session_id = server_handshake->session_id;
             break;
+        }
         default:
             Return RESULT_ERROR_FMT("unexpected response type: %i", packet_header->type);
     }
     
-    
-    try(_s, i, socket_open_TCP());
-    EncryptedSocketTCP_construct(&conn->content_socket, _s, conn->session_key);
-    // TODO: how to connect the second socket to the server and associate it with current session?
-    //try_void(socket_connect(conn->content_socket.sock, conn->server_end????));
-
     success = true;
     Return RESULT_VALUE(p, conn);
 }

src/client/client.c

@@ -15,12 +15,12 @@ static const str farewell_art = STR(
     "\\(_,J J                          L l`,)/\n"
 );
 
-static ClientCredential* _client_credential = NULL;
+static ClientCredentials* _client_credentials = NULL;
 static ServerConnection* _server_connection = NULL;
 
 static Result(void) commandExec(str command, bool* stop);
 
-static Result(void) askUserNameAndPassword(ClientCredential** cred){
+static Result(void) askUserNameAndPassword(ClientCredentials** cred){
     Deferral(8);
 
     printf("username: ");
@@ -32,7 +32,7 @@ static Result(void) askUserNameAndPassword(ClientCredential** cred){
     // TODO: hide password
     fgets(password, sizeof(password), stdin);
 
-    try(*cred, p, ClientCredential_create(str_from_cstr(username), str_from_cstr(password)));
+    try(*cred, p, ClientCredentials_create(str_from_cstr(username), str_from_cstr(password)));
     Return RESULT_VOID;
 }
 
@@ -43,7 +43,7 @@ Result(void) client_run() {
     }
 
     fputs(greeting_art.data, stdout);
-    try_void(askUserNameAndPassword(&_client_credential));
+    try_void(askUserNameAndPassword(&_client_credentials));
 
     Array(char) input_buf = Array_alloc(char, 10000);
     str command_input = str_null;
@@ -68,7 +68,7 @@ Result(void) client_run() {
     }
 
     free(input_buf.data);
-    ClientCredential_free(_client_credential);
+    ClientCredentials_free(_client_credentials);
     ServerConnection_close(_server_connection);
     Return RESULT_VOID;
 }
@@ -77,7 +77,7 @@ Result(void) client_run() {
 
 static Result(void) commandExec(str command, bool* stop){
     Deferral(64);
-    char answer_buf[512];
+    char answer_buf[10000];
     const u32 answer_buf_size = sizeof(answer_buf);
     if(is_alias("q") || is_alias("quit") || is_alias("exit")){
         fputs(farewell_art.data, stdout);
@@ -89,6 +89,7 @@ static Result(void) commandExec(str command, bool* stop){
     else if(is_alias("h") || is_alias("help")){
         puts(
             "COMMANDS:\n"
+            "h, help                        Show this message.\n"
             "q, quit, exit                  Close the program.\n"
             "clear                          Clear the screen.\n"
             "j, join                        Join a server.\n"
@@ -103,8 +104,8 @@ static Result(void) commandExec(str command, bool* stop){
         str new_server_link = str_from_cstr(answer_buf);
         str_trim(&new_server_link, true);
 
-        printf("connecting to server %s\n", new_server_link.data);
+        printf("connecting to server...\n");
-        try(_server_connection, p, ServerConnection_open(_client_credential, new_server_link.data));
+        try(_server_connection, p, ServerConnection_open(_client_credentials, new_server_link.data));
 
         // TODO: request server info
         // show server info

src/client/client.h

@@ -5,15 +5,15 @@
 
 Result(void) client_run();
 
-typedef struct ClientCredential {
+typedef struct ClientCredentials {
     str username;
     Array(u8) aes_key;
     AESBlockEncryptor user_data_aes_enc;
     AESBlockDecryptor user_data_aes_dec;
-} ClientCredential;
+} ClientCredentials;
 
-Result(ClientCredential*) ClientCredential_create(str username, str password);
+Result(ClientCredentials*) ClientCredentials_create(str username, str password);
-void ClientCredential_free(ClientCredential* cred);
+void ClientCredentials_free(ClientCredentials* cred);
 
 typedef struct ServerConnection {
     u64 session_id;
@@ -21,9 +21,8 @@ typedef struct ServerConnection {
     br_rsa_public_key server_pk;
     RSAEncryptor rsa_enc;
     Array(u8) session_key;
-    EncryptedSocketTCP system_socket;
+    EncryptedSocketTCP sock;
-    EncryptedSocketTCP content_socket;
 } ServerConnection;
 
-Result(ServerConnection*) ServerConnection_open(ClientCredential* client_credential, cstr server_link_cstr);
+Result(ServerConnection*) ServerConnection_open(ClientCredentials* client_credentials, cstr server_link_cstr);
 void ServerConnection_close(ServerConnection* conn);

src/config.c

@@ -0,0 +1,36 @@
+#include "config.h"
+
+Result(void) config_findValue(str config_str, str key, str* value, bool throwNotFoundError){
+    u32 line_n = 0;
+    while(config_str.size > 0){
+        line_n++;
+        i32 line_end = str_seekChar(config_str, '\n', 0);
+        if(line_end < 0)
+            line_end = config_str.size - 1;
+        str line = str_sliceBefore(config_str, line_end);
+        config_str = str_sliceAfter(config_str, line_end + 1);
+        
+        i32 sep_pos = str_seekChar(line, '=', 1);
+        if(sep_pos < 0){
+            //not a 'key = value' line
+            continue;
+        }
+
+        str line_key = str_sliceBefore(line, sep_pos - 1);
+        str_trim(&line_key, false);
+        if(str_equals(line_key, key)){
+            str line_value = str_sliceAfter(line, sep_pos + 1);
+            str_trim(&line_value, false);
+            *value = line_value;
+            return RESULT_VOID;
+        }
+    }
+
+    if(throwNotFoundError){
+        char* key_cstr = str_copy(key).data;
+        char* err_msg = sprintf_malloc(key.size + 64, "can't find key '%s'", key_cstr);
+        free(key_cstr);
+        return RESULT_ERROR(err_msg, true);
+    }
+    return RESULT_VOID;
+}

src/config.h

@@ -0,0 +1,6 @@
+#pragma once
+#include "tlibc/errors.h"
+#include "tlibc/string/str.h"
+
+/// searches for pattern `key = value`
+Result(void) config_findValue(str config_str, str key, str* value, bool throwNotFoundError);

src/cryptography/AES.c

@@ -4,15 +4,13 @@
 // write data from src to array and increment array data pointer
 static inline void __Array_writeNext(Array(u8)* dst, u8* src, size_t size){
     memcpy(dst->data, src, size);
-    dst->data = (u8*)dst->data + size;
+    *dst = Array_sliceAfter(*dst, size);
-    dst->size -= size;
 }
 
 // read data from array to dst and increment array data pointer
 static inline void __Array_readNext(u8* dst, Array(u8)* src, size_t size){
     memcpy(dst, src->data, size);
-    src->data = (u8*)src->data + size;
+    *src = Array_sliceAfter(*src, size);
-    src->size -= size;
 }
 
 

src/cryptography/RSA.c

@@ -31,7 +31,7 @@ Result(void) RSA_generateKeyPair(u32 key_size,
     Return RESULT_VOID;
 }
 
-Result(void) RSA_generateKeyPairFromTime(u32 key_size, 
+Result(void) RSA_generateKeyPairFromSystemRandom(u32 key_size, 
     br_rsa_private_key* sk, br_rsa_public_key* pk)
 {
     Deferral(8);
@@ -122,7 +122,7 @@ Result(void) RSA_parsePublicKey_base64(const str src, br_rsa_public_key* pk){
     pk->elen = 4;
     pk->nlen = key_buffer_size - 4;
     pk->e = pk->n + pk->nlen;
-    u32 offset = str_seekChar(src, ':', 14) + 1;
+    u32 offset = str_seekChar(src, ':', 10) + 1;
     if(offset == 0){
         Return RESULT_ERROR("missing ':' before key data", false);
     }
@@ -155,7 +155,7 @@ Result(void) RSA_parsePrivateKey_base64(const str src, br_rsa_private_key* sk){
     sk->dp = sk->q + field_len;
     sk->dq = sk->dp + field_len;
     sk->iq = sk->dq + field_len;
-    u32 offset = str_seekChar(src, ':', 14) + 1;
+    u32 offset = str_seekChar(src, ':', 10) + 1;
     if(offset == 0){
         Return RESULT_ERROR("missing ':' before key data", false);
     }

src/cryptography/RSA.h

@@ -12,7 +12,7 @@
 
 #define RSA_DEFAULT_KEY_SIZE 3072
 
-/// @brief generate random key pair based on system time
+/// @brief generate random key pair
 /// @param key_size size of public key in bits (2048/3072/4096)
 /// @param sk key for decryption
 /// @param pk key for encryption
@@ -21,7 +21,8 @@ Result(void) RSA_generateKeyPair(u32 key_size,
     br_rsa_private_key* sk, br_rsa_public_key* pk,
     const br_prng_class** rng_vtable_ptr);
 
-Result(void) RSA_generateKeyPairFromTime(u32 key_size, 
+/// @brief generate random key pair using system crypto-rng provider
+Result(void) RSA_generateKeyPairFromSystemRandom(u32 key_size, 
     br_rsa_private_key* sk, br_rsa_public_key* pk);
 
 Result(void) RSA_generateKeyPairFromPassword(u32 key_size, 

src/log.h

@@ -0,0 +1,8 @@
+#pragma once
+#include <stdio.h>
+
+#define log(context, severity, format, ...) printf("[%s][" severity "]: " format "\n", context ,##__VA_ARGS__)
+#define logDebug(context, format, ...) log(context, "DEBUG", format ,##__VA_ARGS__)
+#define logInfo(context, format, ...) log(context, "INFO", format ,##__VA_ARGS__)
+#define logWarning(context, format, ...) log(context, "WARNING", format ,##__VA_ARGS__)
+#define logError(context, format, ...) log(context, "ERROR", format ,##__VA_ARGS__)

src/main.c

@@ -2,10 +2,14 @@
 #include "client/client.h"
 #include "server/server.h"
 
+#define _DEFAULT_CONFIG_PATH_CLIENT "tcp-chat-client.config"
+#define _DEFAULT_CONFIG_PATH_SERVER "tcp-chat-server.config"
+
 typedef enum ProgramMode {
     Client,
     Server,
-    RsaGen,
+    RsaGenStdin,
+    RsaGenRandom,
 } ProgramMode;
 
 #define arg_is(LITERAL) str_equals(arg_str, STR(LITERAL))
@@ -19,8 +23,9 @@ int main(const int argc, cstr const* argv){
     }
 
     ProgramMode mode = Client;
-    cstr server_endpoint_cstr;
+    cstr server_endpoint_cstr = NULL;
-    u32 key_size = RSA_DEFAULT_KEY_SIZE;
+    cstr config_path = NULL;
+    u32 key_size = 0;
 
     for(int argi = 1; argi < argc; argi++){
         str arg_str = str_from_cstr(argv[argi]);
@@ -30,7 +35,12 @@ int main(const int argc, cstr const* argv){
                 "no arguments                   Interactive client mode.\n"
                 "-h, --help                     Show this message.\n"
                 "-l, --listen [addr:port]       Start server.\n"
-                "--rsa-gen [size]               Generate RSA private and public keys based on stdin data (64Kb max)\n"
+                "--config [path]                Load config from specified path.\n"
+                "    Default path for config is '" _DEFAULT_CONFIG_PATH_CLIENT "' or '" _DEFAULT_CONFIG_PATH_SERVER "'\n"
+                "--rsa-gen-stdin [size]         Generate RSA private and public keys based on stdin data (64Kb max).\n"
+                "    size: 2048 / 3072 (default) / 4096\n"
+                "    Usage: `cat somefile | tcp-chat --gen-rsa-stdin`\n"
+                "--rsa-gen-random [size]        Generate random RSA private and public keys.\n"
                 "    size: 2048 / 3072 (default) / 4096\n"
             );
             Return 0;
@@ -48,18 +58,39 @@ int main(const int argc, cstr const* argv){
             }
             server_endpoint_cstr = argv[argi];
         }
-        else if(arg_is("--rsa-gen")){
+        else if(arg_is("--config")){
+            if(++argi >= argc){
+                printfe("ERROR: no config path specified\n");
+                Return 1;
+            }
+            config_path = argv[argi];
+        }
+        else if(arg_is("--rsa-gen-stdin")){
             if(mode != Client){
                 printf("program mode is set already\n");
                 Return 1;
             }
 
-            mode = RsaGen;
+            mode = RsaGenStdin;
             if(++argi >= argc){
+                key_size = RSA_DEFAULT_KEY_SIZE;
+            }
+            else if(sscanf(argv[argi], "%u", &key_size) != 1){
                 printfe("ERROR: no key size specified\n");
+            }
+        }
+        
+        else if(arg_is("--rsa-gen-random")){
+            if(mode != Client){
+                printf("program mode is set already\n");
                 Return 1;
             }
-            if(sscanf(argv[argi], "%u", &key_size) != 1){
+
+            mode = RsaGenRandom;
+            if(++argi >= argc){
+                key_size = RSA_DEFAULT_KEY_SIZE;
+            }
+            else if(sscanf(argv[argi], "%u", &key_size) != 1){
                 printfe("ERROR: no key size specified\n");
             }
         }
@@ -75,13 +106,21 @@ int main(const int argc, cstr const* argv){
     Defer(network_deinit());
     
     switch(mode){
-        case Client:
+        case Client: {
+            if(config_path == NULL)
+                config_path = _DEFAULT_CONFIG_PATH_CLIENT;
             try_fatal_void(client_run());
             break;
-        case Server:
+        }
-            try_fatal_void(server_run(server_endpoint_cstr));
+
+        case Server: {
+            if(config_path == NULL)
+                config_path = _DEFAULT_CONFIG_PATH_SERVER;
+            try_fatal_void(server_run(server_endpoint_cstr, config_path));
             break;
-        case RsaGen:{
+        }
+
+        case RsaGenStdin: {
                 size_t input_max_size = 64*1024;
                 char* input_buf = malloc(input_max_size);
                 Defer(free(input_buf));
@@ -91,7 +130,7 @@ int main(const int argc, cstr const* argv){
                     Return 1;
                 }
                 str input_str = str_construct(input_buf, read_n, false);
-                printfe("generating RSA key pair...\n");
+                printfe("generating RSA key pair based on stdin...\n");
                 br_rsa_private_key sk;
                 br_rsa_public_key pk;
                 try_fatal_void(RSA_generateKeyPairFromPassword(key_size, &sk, &pk, input_str));
@@ -99,18 +138,37 @@ int main(const int argc, cstr const* argv){
                     RSA_destroyPrivateKey(&sk);
                     RSA_destroyPublicKey(&pk);
                 );
-                puts("-----BEGIN RSA PRIVATE KEY-----");
+                
                 str sk_str = RSA_serializePrivateKey_base64(&sk);
-                puts(sk_str.data);
+                printf("rsa_private_key = %s\n", sk_str.data);
                 free(sk_str.data);
-                puts("-----END RSA PRIVATE KEY-------");
+                
-                puts("-----BEGIN RSA PUBLIC KEY------");
                 str pk_str = RSA_serializePublicKey_base64(&pk);
-                puts(pk_str.data);
+                printf("\nrsa_public_key = %s\n", pk_str.data);
                 free(pk_str.data);
-                puts("-----END RSA PUBLIC KEY--------");
             }
             break;
+        
+        case RsaGenRandom: {
+                printfe("generating random RSA key pair...\n");
+                br_rsa_private_key sk;
+                br_rsa_public_key pk;
+                try_fatal_void(RSA_generateKeyPairFromSystemRandom(key_size, &sk, &pk));
+                Defer(
+                    RSA_destroyPrivateKey(&sk);
+                    RSA_destroyPublicKey(&pk);
+                );
+
+                str sk_str = RSA_serializePrivateKey_base64(&sk);
+                printf("rsa_private_key = %s\n", sk_str.data);
+                free(sk_str.data);
+                
+                str pk_str = RSA_serializePublicKey_base64(&pk);
+                printf("\nrsa_public_key = %s\n", pk_str.data);
+                free(pk_str.data);
+            }
+            break;
+        
         default:
             printfe("ERROR: invalid program mode %i\n", mode);
             Return 1;

src/network/encrypted_sockets.c

@@ -24,6 +24,7 @@ Result(i32) EncryptedSocketTCP_recv(EncryptedSocketTCP* ptr,
 {
     Deferral(4);
     try(i32 received_size, i, socket_recv(ptr->sock, encrypted_buf, flags));
+    //TODO: return something when received_size == 0 (socket has been closed)
     encrypted_buf.size = received_size;
     try(i32 decrypted_size, u, AESStreamDecryptor_decrypt(&ptr->dec, encrypted_buf, decrypted_buf));
     Return RESULT_VALUE(i, decrypted_size);

src/network/tcp-chat-protocol/constant.h

@@ -6,11 +6,13 @@
 
 extern const Magic64 PacketHeader_MAGIC;
 
+// sizeof(PacketHeader) must be 64 
 typedef struct PacketHeader {
     Magic64 magic;
     u8 protocol_version;
-    u8 _reserved;
+    u8 _reserved1;
     u16 type;
+    u32 _reserved4;
     u64 content_size;
 } __attribute__((aligned(64))) PacketHeader;
 

src/network/tcp-chat-protocol/v1.c

@@ -8,3 +8,7 @@ Result(void) ClientHandshake_tryConstruct(ClientHandshake* ptr, Array(u8) sessio
     Return RESULT_VOID;
 }
 
+void ServerHandshake_construct(ServerHandshake* ptr, u64 session_id){
+    PacketHeader_construct(&ptr->header, PROTOCOL_VERSION, PacketType_ClientHandshake, sizeof(session_id));
+    ptr->session_id = session_id;
+}

src/network/tcp-chat-protocol/v1.h

@@ -4,6 +4,7 @@
 
 #define PROTOCOL_VERSION 1 /* 1.0.0 */
 
+
 typedef enum PacketType {
     PacketType_Invalid,
     PacketType_ErrorMessage,
@@ -11,11 +12,13 @@ typedef enum PacketType {
     PacketType_ServerHandshake,
 } __attribute__((__packed__)) PacketType;
 
+
 typedef struct ErrorMessage {
     PacketHeader header;
     /* content stream of size `header.content_size` */
 } ErrorMessage;
 
+
 typedef struct ClientHandshake {
     PacketHeader header;
     u8 session_key[AES_SESSION_KEY_SIZE];
@@ -28,3 +31,5 @@ typedef struct ServerHandshake {
     PacketHeader header;
     u64 session_id;
 } ServerHandshake;
+
+void ServerHandshake_construct(ServerHandshake* ptr, u64 session_id);

src/server/ClientConnection.c

@@ -1,10 +1,87 @@
 #include "server.h"
+#include "network/tcp-chat-protocol/v1.h"
 
 void ClientConnection_close(ClientConnection* conn){
     if(conn == NULL)
         return;
-    socket_close(conn->system_socket.sock);
+    socket_close(conn->sock.sock);
-    socket_close(conn->content_socket.sock);
     free(conn->session_key.data);
     free(conn);
 }
+
+Result(ClientConnection*) ClientConnection_accept(ServerCredentials* server_credentials, 
+    Socket sock_tcp, EndpointIPv4 client_end, u64 session_id)
+{
+    Deferral(32);
+
+    ClientConnection* conn = (ClientConnection*)malloc(sizeof(ClientConnection));
+    memset(conn, 0, sizeof(*conn));
+    bool success = false;
+    Defer(
+        if(!success)
+            ClientConnection_close(conn);
+    );
+
+    conn->client_end = client_end;
+    conn->session_id = session_id;
+    conn->session_key = Array_alloc_size(AES_SESSION_KEY_SIZE);
+
+    Array(u8) enc_buf = Array_alloc_size(8*1024);
+    Defer(free(enc_buf.data));
+    Array(u8) dec_buf = Array_alloc_size(8*1024);
+    Defer(free(dec_buf.data));
+    u32 enc_size = 0, dec_size = 0;
+
+    // receive message encrypted by server public key
+    try(enc_size, u, 
+        socket_recv(
+            sock_tcp,
+            Array_sliceBefore(enc_buf, server_credentials->rsa_pk.nlen),
+            SocketRecvFlag_WaitAll
+        )
+    );
+
+    // decrypt the message using server private key
+    RSADecryptor rsa_dec;
+    RSADecryptor_construct(&rsa_dec, &server_credentials->rsa_sk);
+    try(dec_size, u, 
+        RSADecryptor_decrypt(
+            &rsa_dec,
+            Array_sliceBefore(enc_buf, enc_size)
+        )
+    );
+    
+    // validate client handshake
+    if(dec_size != sizeof(ClientHandshake)){
+        Return RESULT_ERROR_FMT(
+            "decrypted message (size: %u) is not a ClientHandshake (size: %u)",
+            dec_size, (u32)sizeof(ClientHandshake) 
+        );
+    }
+    ClientHandshake* client_handshake = dec_buf.data;
+    try_void(PacketHeader_validateMagic(&client_handshake->header));
+    if(client_handshake->header.type != PacketType_ClientHandshake){
+        Return RESULT_ERROR_FMT(
+            "received message of unexpected type: %u",
+            client_handshake->header.type
+        );
+    }
+
+    // use received session key
+    memcpy(conn->session_key.data, client_handshake->session_key, conn->session_key.size);
+    EncryptedSocketTCP_construct(&conn->sock, sock_tcp, conn->session_key);
+    
+    // construct ServerHandshake in dec_buf
+    ServerHandshake_construct((ServerHandshake*)dec_buf.data, session_id);
+    // send ServerHandshake over encrypted TCP socket
+    try_void(
+        EncryptedSocketTCP_send(
+            &conn->sock,
+            Array_sliceBefore(dec_buf, sizeof(ServerHandshake)),
+            enc_buf
+        )
+    );
+
+    success = true;
+    Return RESULT_VALUE(p, conn);
+}

src/server/ServerCredentials.c

@@ -0,0 +1,26 @@
+#include "server.h"
+
+
+Result(ServerCredentials*) ServerCredentials_create(const str rsa_sk_base64, const str rsa_pk_base64){
+    Deferral(4);
+    
+    ServerCredentials* cred = (ServerCredentials*)malloc(sizeof(ServerCredentials));
+    memset(cred, 0, sizeof(*cred));
+    bool success = false;
+    Defer(
+        if(!success)
+            ServerCredentials_free(cred);
+    );
+
+    try_void(RSA_parsePrivateKey_base64(rsa_sk_base64, &cred->rsa_sk));
+    try_void(RSA_parsePublicKey_base64(rsa_pk_base64, &cred->rsa_pk));
+    
+    success = true;
+    Return RESULT_VALUE(p, cred);
+}
+
+void ServerCredentials_free(ServerCredentials* cred){
+    RSA_destroyPrivateKey(&cred->rsa_sk);
+    RSA_destroyPublicKey(&cred->rsa_pk);
+    free(cred);
+}

src/server/server.c

@@ -1,8 +1,9 @@
-#include "server.h"
-#include "db/idb.h"
 #include <pthread.h>
-
+#include "tlibc/filesystem.h"
-static void* handle_connection(void* _args);
+#include "db/idb.h"
+#include "server.h"
+#include "config.h"
+#include "log.h"
 
 typedef struct ConnectionHandlerArgs {
     Socket accepted_socket;
@@ -10,22 +11,57 @@ typedef struct ConnectionHandlerArgs {
     u64 session_id;
 } ConnectionHandlerArgs;
 
-Result(void) server_run(cstr server_endpoint_str){
+static void* handle_connection(void* _args);
+static Result(void) try_handle_connection(ConnectionHandlerArgs* args, cstr log_ctx);
+
+
+static ServerCredentials* _server_credentials = NULL;
+
+
+static Result(void) parseConfig(cstr config_path){
+    Deferral(8);
+
+    // open file
+    try(FILE* config_file, p, file_open(config_path, FO_ReadExisting));
+    // read whole file into Array(char)
+    try(i64 config_file_size, i, file_getSize(config_file));
+    Array(char) config_buf = Array_alloc(char, config_file_size);
+    Defer(free(config_buf.data));
+    try_void(file_readBytesArray(config_file, config_buf));
+    str config_str = Array_castTo_str(config_buf, false);
+
+    str sk_base64;
+    str pk_base64;
+    try_void(config_findValue(config_str, STR("rsa_private_key"), &sk_base64, true));
+    try_void(config_findValue(config_str, STR("rsa_public_key"), &pk_base64, true));
+    try(_server_credentials, p, ServerCredentials_create(sk_base64, pk_base64));
+    
+    Return RESULT_VOID;
+}
+
+Result(void) server_run(cstr server_endpoint_cstr, cstr config_path){
     Deferral(32);
+    cstr log_ctx = "Server/MainThread";
+    logInfo(log_ctx, "starting server");
+    logDebug(log_ctx, "parsing config");
+    try_void(parseConfig(config_path));
+
+    logDebug(log_ctx, "initializing main socket");
     EndpointIPv4 server_end;
-    EndpointIPv4_parse(server_endpoint_str, &server_end);
+    EndpointIPv4_parse(server_endpoint_cstr, &server_end);
-    //TODO: add log
     try(Socket main_socket, i, socket_open_TCP());
     try_void(socket_bind(main_socket, server_end));
     try_void(socket_listen(main_socket, 512));
+    logInfo(log_ctx, "server is listening at %s", server_endpoint_cstr);
 
     u64 session_id = 1;
-
     while(true){
         ConnectionHandlerArgs* args = (ConnectionHandlerArgs*)malloc(sizeof(ConnectionHandlerArgs));
         try(args->accepted_socket, i, socket_accept(main_socket, &args->client_end));
         args->session_id = session_id++;
         pthread_t conn_thread = {0};
+        //TODO: use async IO instead of threads to not waste system resources 
+        // while waiting for incoming data in 100500 threads
         try_stderrcode(pthread_create(&conn_thread, NULL, handle_connection, args));
     }
 
@@ -33,13 +69,41 @@ Result(void) server_run(cstr server_endpoint_str){
 }
 
 static void* handle_connection(void* _args){
-    Deferral(64);
+    ConnectionHandlerArgs* args = (ConnectionHandlerArgs*)_args;
-    //ConnectionHandlerArgs* args = (ConnectionHandlerArgs*)_args;
+    char log_ctx[64];
-    Defer(free(_args));
+    sprintf(log_ctx, "Session-" IFWIN("%llx", "%lx"), args->session_id);
-    // TODO: receive handshake and session key
     
-    //ClientConnection conn;
+    Result(void) r = try_handle_connection(args, log_ctx);
+    if(r.error){
+        str error_s = Error_toStr(r.error);
+        logError(log_ctx, "%s", error_s.data);
+        free(error_s.data);
+    }
     
-
+    return NULL;
-    Return NULL;
+}
+
+static Result(void) try_handle_connection(ConnectionHandlerArgs* args, cstr log_ctx){
+    Deferral(64);
+    Defer(free(args));
+    
+    ClientConnection* conn = NULL;
+    Defer(ClientConnection_close(conn));
+    // establish encrypted connection
+    try(conn, p, 
+        ClientConnection_accept(
+            _server_credentials,
+            args->accepted_socket,
+            args->client_end,
+            args->session_id
+        )
+    );
+    logDebug(log_ctx, "session accepted");
+
+    // handle requests
+    while(true){
+        sleepMsec(10);
+    }
+
+    Return RESULT_VOID;
 }

src/server/server.h

@@ -3,12 +3,33 @@
 #include "cryptography/RSA.h"
 #include "network/encrypted_sockets.h"
 
-Result(void) server_run(cstr server_endpoint_str);
+Result(void) server_run(cstr server_endpoint_cstr, cstr config_path);
+
+
+typedef struct ServerCredentials {
+    br_rsa_private_key rsa_sk;
+    br_rsa_public_key rsa_pk;
+} ServerCredentials;
+
+Result(ServerCredentials*) ServerCredentials_create(const str rsa_sk_base64, const str rsa_pk_base64);
+
+void ServerCredentials_free(ServerCredentials* cred);
+
+
+typedef struct ServerMetadata {
+    str name;
+    str description;
+} ServerMetadata;
+
 
 typedef struct ClientConnection {
     u64 session_id;
     EndpointIPv4 client_end;
     Array(u8) session_key;
-    EncryptedSocketTCP system_socket;
+    EncryptedSocketTCP sock;
-    EncryptedSocketTCP content_socket;
 } ClientConnection;
+
+Result(ClientConnection*) ClientConnection_accept(ServerCredentials* server_credentials, 
+    Socket sock, EndpointIPv4 client_end, u64 session_id);
+
+void ClientConnection_close(ClientConnection* conn);