Add 'server/' from commit '800090542d91beae40bc81fc41b67ba61c47da77'

git-subtree-dir: server
git-subtree-mainline: 6a4054c15a
git-subtree-split: 800090542d

server/kordophone/Hooking/hooking.h

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+//
+//  hooking.h
+//  MessagesBridge
+//
+//  Created by James Magahern on 11/13/18.
+//  Copyright © 2018 James Magahern. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+// Returns success and a populated errorString on error.
+BOOL HookIMAgent(const char *hookDylibPath, char **errorString);

server/kordophone/Hooking/hooking.m

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+//
+//  hooking.c
+//  kordophoned
+//
+//  Created by James Magahern on 11/13/18.
+//  Copyright © 2018 James Magahern. All rights reserved.
+//
+
+#include "hooking.h"
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <unistd.h>
+
+BOOL HookIMAgent(const char *relativeDylibPath, char **errorString)
+{
+    MBIMLogInfo(@"Hooking imagent");
+    
+    const char *hookDylibPath = realpath(relativeDylibPath, NULL);
+    
+    // See if file is there.
+    int succ = access(hookDylibPath, R_OK);
+    if (succ != 0) {
+        *errorString = "Unable to access hook dylib. Does file exist?";
+        return NO;
+    }
+    
+    // Make sure we can load the dylib (filters out codesigning issues)
+    void *handle = dlopen(hookDylibPath, RTLD_NOW);
+    if (!handle) {
+        *errorString = dlerror();
+        return NO;
+    }
+    
+    /*********
+     ***********
+     PROBABLY DON'T DO THIS
+     
+     If other processes start and load agentHook, then they will crash because dyld tries to
+     interpose a function that doesn't exist.
+     
+     A better way (maybe put this in a script or something):
+     ( But launchctl debug needs to run as root :( )
+     
+     $ launchctl debug gui/501/com.apple.imagent --environment DYLD_INSERT_LIBRARIES=(path to libagentHook.dylib)
+     
+     $ launchctl kill SIGKILL gui/501/com.apple.imagent
+     
+     // then let it restart...
+     
+     **/
+    
+    // Set launchd DYLD_INSERT_LIBRARIES environment variable
+    const char *systemCommandFormatString = "/bin/launchctl setenv DYLD_INSERT_LIBRARIES %s";
+    size_t bufferSize = strlen(systemCommandFormatString) + strlen(hookDylibPath) + 2;
+    char *systemCommand = (char *)malloc(sizeof(char) * bufferSize);
+    
+    sprintf(systemCommand, "/bin/launchctl setenv DYLD_INSERT_LIBRARIES %s", hookDylibPath);
+    int setEnvSucc = system(systemCommand);
+    if (setEnvSucc != 0) {
+        *errorString = "Unable to set launchd environment variable.";
+        return NO;
+    }
+    
+    MBIMLogInfo(@"Successfully setup environment variables");
+    
+    // Kill imagent so the new one has the loaded bundle
+    MBIMLogInfo(@"Killing imagent...");
+    int killAgentSuccess = system("killall imagent");
+    
+    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+        system("/bin/launchctl unsetenv DYLD_INSERT_LIBRARIES");
+    });
+    
+    return (killAgentSuccess == 0);
+}