ios - cannot decrypt after encryption - ios

I'm having troubles decrypting pdf files and displaying them with presentViewController after they are encrypted.
When I download the pdf files, they are being encrypted like this:
NSData *pdfData = [[NSFileManager defaultManager] contentsAtPath:filePathDocumetFolder];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documents = [paths objectAtIndex:0];
NSString *docFolder = [NSString stringWithFormat:#"/Documents/%#", documentFilePath];
NSString *filePath = [documents stringByAppendingPathComponent:docFolder];
NSString *pdfName = [NSString stringWithString:filename ];
NSError *error;
NSData *encryptedPdf = [RNEncryptor encryptData:pdfData withSettings:kRNCryptorAES256Settings password:#"A_SECRET_PASSWORD" error:&error];
if(error){
NSLog(#"error: %#", error);
}
NSLog(#"where?? FileTra%#", filePath);
[encryptedPdf writeToFile:[filePath stringByAppendingPathComponent:pdfName] atomically:YES];
I know that this encryption above works, as when I browse the filesystem with iExplorer, I cannot open the files because they are protected.
In my DocumentHandle controller I'm trying to decrypt them so that they can be viewed:
NSDictionary* dict = [command.arguments objectAtIndex:0];
NSString* urlStr = dict[#"url"];
NSURL* url = [NSURL URLWithString:urlStr];
NSString* fileName = [url path];
NSString* path = [NSTemporaryDirectory() stringByAppendingPathComponent: fileName];
NSData *dataEn = [[NSFileManager defaultManager] contentsAtPath:[path stringByAppendingPathComponent:fileName]];
NSLog(#"this to decrypt%#", [path stringByAppendingPathComponent:fileName]);
NSData *decryp = [RNDecryptor decryptData:dataEn withSettings:kRNCryptorAES256Settings password:#"A_SECRET_PASSWORD" error:nil];
[decryp writeToURL:[[NSURL alloc] initFileURLWithPath:path] atomically:YES];
if(decryp){
NSLog(#"decrypted");
}else{
NSLog(#" not decrypted");
}
weakSelf.fileUrl = [[NSURL alloc] initFileURLWithPath:path];
For some reason, the pdf files are not being decrypted and I'm being presented with a blank file even thought I'm receiving NSLog as decrypted :(
Can anyone help me please? thank you

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How can I check if a file is download and save on device? Help me please.
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if (_index1 == 0) {
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If you want to see if the file music.mp3 is in your Documents folder:
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This only makes sense if that file is always the same file. If it can be different files then you need to associate the URL you use to download with the file you stored it in.

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Here is my code.I have more 10 pdf and want to store them locally on device and display next time without download.
It saves the pdf again and i cannot check whether it is downloaded or not ?
Please help me
I am not sure what you mean but, to download a file , you need to use NSData:
NSString *stringURL = #"your file URL";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
if ( urlData )
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:#"%#/%#", documentsDirectory,#"filename.extension"];
[urlData writeToFile:filePath atomically:YES];
}
Now the downloaded file exists at filePath and you can get it by using:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"filename with extension"];
NSString *content = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:NULL];
you can try this to check if file exists at file path:
NSString* documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* file = [documentsPath stringByAppendingPathComponent:#"filename"];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:file];
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//dont download, just grab it and display it
}
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Change your SetDocuments like this
-(void)SetDocuments{
NSArray* doc;
//doc = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
doc = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
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if (!userDir) {
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NSError *error = nil;
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