nsstring - How to get iOS appStoreReceiptURL into Base 64 Encoded String?

Question

I want to use appStoreReceiptURL to see which version of the app someone purchased. How can I get this into a string?

I'm testing this by downloading the app from the store, then running a new version of the app from Xcode. Here is what I've tried:

NSURL *receiptUrl = [[NSBundle mainBundle] appStoreReceiptURL];
NSLog(@"receiptUrl %@",[receiptUrl path]);
if ([[NSFileManager defaultManager] fileExistsAtPath:[receiptUrl path]]) {
        NSLog(@"exists");
         NSError *error;
         NSString *receiptString = [[NSString alloc] initWithContentsOfFile:[receiptUrl path] encoding:NSUTF8StringEncoding error:&error];
         if (receiptString == nil) {
              NSLog(@"Error: %@", [error localizedDescription]);
         } else {
             NSLog(@"Receipt: %@",receiptString);
        }

} else {
        NSLog(@"does not exist");
}

This is what I get:

receiptUrl /var/mobile/Applications/E612F261-2D30-416E-BF82-F24xxxx8860/StoreKit/receipt
exists
Error: The operation couldn’t be completed. (Cocoa error 261.)

Answer 1

I figured out the trick is to read the receipt as data then base 64 encode it from the data. Here's what worked for me if it helps anyone else. Also thanks to this thread for the base 64 encoding: Converting NSData to base64

// this returns an NSDictionary of the app's store receipt, status=0 for good, -1 for bad
- (NSDictionary *) getStoreReceipt:(BOOL)sandbox {

    NSArray *objects;
    NSArray *keys;
    NSDictionary *dictionary;

    BOOL gotreceipt = false;

    @try {

        NSURL *receiptUrl = [[NSBundle mainBundle] appStoreReceiptURL];

        if ([[NSFileManager defaultManager] fileExistsAtPath:[receiptUrl path]]) {

            NSData *receiptData = [NSData dataWithContentsOfURL:receiptUrl];

            NSString *receiptString = [self base64forData:receiptData];

            if (receiptString != nil) {

                objects = [[NSArray alloc] initWithObjects:receiptString, nil];
                keys = [[NSArray alloc] initWithObjects:@"receipt-data", nil];
                dictionary = [[NSDictionary alloc] initWithObjects:objects forKeys:keys];

                NSString *postData = [self getJsonStringFromDictionary:dictionary];

                NSString *urlSting = @"https://buy.itunes.apple.com/verifyReceipt";
                if (sandbox) urlSting = @"https://sandbox.itunes.apple.com/verifyReceipt";

                dictionary = [self getJsonDictionaryWithPostFromUrlString:urlSting andDataString:postData];

                if ([dictionary objectForKey:@"status"] != nil) {

                    if ([[dictionary objectForKey:@"status"] intValue] == 0) {

                        gotreceipt = true;

                    }
                }

            }

        }

    } @catch (NSException * e) {
        gotreceipt = false;
    }

    if (!gotreceipt) {
        objects = [[NSArray alloc] initWithObjects:@"-1", nil];
        keys = [[NSArray alloc] initWithObjects:@"status", nil];
        dictionary = [[NSDictionary alloc] initWithObjects:objects forKeys:keys];
    }

    return dictionary;
}



- (NSDictionary *) getJsonDictionaryWithPostFromUrlString:(NSString *)urlString andDataString:(NSString *)dataString {
    NSString *jsonString = [self getStringWithPostFromUrlString:urlString andDataString:dataString];
    NSLog(@"%@", jsonString); // see what the response looks like
    return [self getDictionaryFromJsonString:jsonString];
}


- (NSDictionary *) getDictionaryFromJsonString:(NSString *)jsonstring {
    NSError *jsonError;
    NSDictionary *dictionary = (NSDictionary *) [NSJSONSerialization JSONObjectWithData:[jsonstring dataUsingEncoding:NSUTF8StringEncoding] options:0 error:&jsonError];
    if (jsonError) {
       dictionary = [[NSDictionary alloc] init];
    }
    return dictionary;
}


- (NSString *) getStringWithPostFromUrlString:(NSString *)urlString andDataString:(NSString *)dataString {
    NSString *s = @"";
    @try {
        NSData *postdata = [dataString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
        NSString *postlength = [NSString stringWithFormat:@"%d", [postdata length]];
        NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
        [request setURL:[NSURL URLWithString:urlString]];
            [request setTimeoutInterval:60];
        [request setHTTPMethod:@"POST"];
        [request setValue:postlength forHTTPHeaderField:@"Content-Length"];
        [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
        [request setHTTPBody:postdata];
        NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
        if (data != nil) {
            s = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        }
    }
    @catch (NSException *exception) { 
        s = @"";
    } 
    return s;
}


// from https://stackoverflow.com/questions/2197362/converting-nsdata-to-base64
- (NSString*)base64forData:(NSData*)theData {
    const uint8_t* input = (const uint8_t*)[theData bytes];
    NSInteger length = [theData length];
    static char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    NSMutableData* data = [NSMutableData dataWithLength:((length + 2) / 3) * 4];
    uint8_t* output = (uint8_t*)data.mutableBytes;
    NSInteger i;
    for (i=0; i < length; i += 3) {
        NSInteger value = 0;
        NSInteger j;
        for (j = i; j < (i + 3); j++) {
            value <<= 8;

            if (j < length) {
                value |= (0xFF & input[j]);
            }
        }
        NSInteger theIndex = (i / 3) * 4;
        output[theIndex + 0] =                    table[(value >> 18) & 0x3F];
        output[theIndex + 1] =                    table[(value >> 12) & 0x3F];
        output[theIndex + 2] = (i + 1) < length ? table[(value >> 6)  & 0x3F] : '=';
        output[theIndex + 3] = (i + 2) < length ? table[(value >> 0)  & 0x3F] : '=';
    }
    return [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
}