Dump URL schemes from an iOS system image (stock applications)

ios_image_app_url_dump.m

//
//  ios_image_app_url_dump
//
//  Created by Leptos on 2/19/19.
//  Copyright © 2019 Leptos. All rights reserved.
//

/* compile with:
 * $ clang -fobjc-arc -framework Foundation
 */

#import <Foundation/Foundation.h>

static void dumpBundleURLsToStdout(NSBundle *bundle, BOOL publicOnly, BOOL schemeIndicator) {
    NSArray<NSDictionary *> *appURLs = [bundle objectForInfoDictionaryKey:@"CFBundleURLTypes"];
    if (appURLs.count == 0) {
        return;
    }
    
    NSString *bundleIdentifier = [bundle objectForInfoDictionaryKey:(NSString *)kCFBundleIdentifierKey];
    NSString *bundleDisplayName = [bundle objectForInfoDictionaryKey:(NSString *)kCFBundleNameKey];
    
    NSMutableString *formatted = [NSMutableString stringWithFormat:@"%@ (%@):\n", bundleDisplayName, bundleIdentifier];
    
    BOOL shouldPrint = !publicOnly;
    for (NSDictionary *urlInfo in appURLs) {
        NSString *urlName = urlInfo[@"CFBundleURLName"] ?: @"UNKNUNKN";
        BOOL isPrivate = [urlInfo[@"CFBundleURLIsPrivate"] boolValue];
        if (isPrivate && publicOnly) {
            continue;
        }
        shouldPrint = YES;
        
        [formatted appendFormat:@"    %@", urlName];
        if (!publicOnly) {
            [formatted appendFormat:@" (%s)", isPrivate ? "Private" : "Public"];
        }
        [formatted appendString:@":\n"];
        
        for (NSString *urlScheme in urlInfo[@"CFBundleURLSchemes"]) {
            [formatted appendFormat:@"        %@%@\n", urlScheme, schemeIndicator ? @"://_" : @""];
        }
        [formatted appendString:@"\n"];
    }
    if (shouldPrint) {
        fputs(formatted.UTF8String, stdout);
    }
}

static void dumpBundlesInDirectory(NSString *path, BOOL publicOnly, BOOL schemeIndicator, NSError **error) {
    NSFileManager *const fileManager = [NSFileManager defaultManager];
    NSArray<NSString *> *apps = [fileManager contentsOfDirectoryAtPath:path error:error];
    
    for (NSString *appPath in apps) {
        NSString *fullPath = [path stringByAppendingPathComponent:appPath];
        dumpBundleURLsToStdout([NSBundle bundleWithPath:fullPath], publicOnly, schemeIndicator);
    }
}

static int putUsage(const char *progname) {
    return fprintf(stderr, "Usage: %s [-pl] <ios_root>\n"
                   "    -p : public Schemes only\n"
                   "    -l : generate a list of clickable links\n"
                   "    ios_root : path to the iOS system root\n", progname);
}

int main(int argc, char *argv[]) {
    const char *progname = argv[0];
    
    int publicOnly = NO;
    int schemeIndicator = NO;
    
    if (argc < 2) {
        putUsage(progname);
        return 1;
    }
    
    argc--;
    NSString *systemRoot = @(argv[argc]);
    int c;
    while ((c = getopt(argc, argv, ":pl")) != -1) {
        switch (c) {
            case 'p':
                publicOnly = YES;
                break;
            case 'l':
                schemeIndicator = YES;
                break;
            case '?': {
                putUsage(progname);
                return 1;
            } break;
        }
    }
    
    NSArray<NSString *> *searchDirectories = @[
        @"/Applications",
        // there are versions at "/System/Library/AppPlaceholders" which are asset-only (they should have the same `Info.plist`)
        @"/var/staged_system_apps"
    ];
    for (NSString *searchDirectory in searchDirectories) {
        NSError *err = nil;
        dumpBundlesInDirectory([systemRoot stringByAppendingPathComponent:searchDirectory], publicOnly, schemeIndicator, &err);
        if (err) {
            NSLog(@"[Fatal] %@", err);
            return 1;
        }
    }
    
    /*  there are some additional apps at (checked at a 12.2 and 13.1 beta)
     *     /System/Library/PrivateFrameworks/IDS.framework/identityservicesd.app
     *     /System/Library/PrivateFrameworks/IDSFoundation.framework/IDSCredentialsAgent.app
     *     /System/Library/PrivateFrameworks/IDSFoundation.framework/IDSRemoteURLConnectionAgent.app
     *     /System/Library/PrivateFrameworks/IMCore.framework/imagent.app
     *     /System/Library/PrivateFrameworks/IMDPersistence.framework/IMAutomaticHistoryDeletionAgent.app
     *     /System/Library/PrivateFrameworks/IMTransferServices.framework/IMTransferAgent.app
     *
     *  none of them had URL schemes
     */
}