/*

 File: CryptoServerRequest.m

 Abstract: Handles a server networking request, composed of cryptographic 

 operations, made by a connected client.

 Version: 1.2

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 */

#import "CryptoServer.h"

#import "SecKeyWrapper.h"

#import "CryptoCommon.h"

#import "CryptoServerRequest.h"

#include <CFNetwork/CFSocketStream.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <unistd.h>

#include <arpa/inet.h>

static const uint8_t kMessageBodyBytes[] = kMessageBody;

@implementation CryptoServerRequest

@synthesize istr, ostr, peerName, peerPublicKey, delegate;

- (id)initWithInputStream:(NSInputStream *)readStream 

             outputStream:(NSOutputStream *)writeStream 

                     peer:(NSString *)peerAddress 

                 delegate:(NSObject <CryptoServerRequestDelegate, NSObject> *)anObject {

    if (self = [super init]) {

        self.istr = readStream;

        self.ostr = writeStream;

        self.peerName = peerAddress;

        self.peerPublicKey = nil;

        self.delegate = anObject;

    }

    return self;

}

- (void)runProtocol {

    LOGGING_FACILITY(self.istr != nil && self.ostr != nil, @"Streams not set up properly." );

    if (self.istr && self.ostr) {

        self.istr.delegate = self;

        [self.istr scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

        [self.istr open];

        self.ostr.delegate = self;

        [self.ostr scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

        [self.ostr open];

    }

}

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode

{

    switch(eventCode) {

        case NSStreamEventHasSpaceAvailable:

        {

            if (stream == self.ostr) {

                if ([(NSOutputStream *) stream hasSpaceAvailable] && self.peerPublicKey) { 

                    [self createBlobAndSend];

                }

            }

            break;

        }

        case NSStreamEventHasBytesAvailable:

        {

            if (stream == self.istr) {

                NSData * publicKey = [self receiveData];

                [self.istr close];

                if (publicKey) {

                    self.peerPublicKey = publicKey;

                    if ([self.ostr hasSpaceAvailable]) {

                        [self createBlobAndSend];

                    }

                } else {

                    LOGGING_FACILITY( 0, @"Connected Client sent too large of a key." );

                    [delegate cryptoServerRequestDidReceiveError:self];

                }

            }

            break;

        }

        case NSStreamEventErrorOccurred:

        {

            // No debugging facility because we don't want to exit even in DEBUG.

            // It's annoying.

            NSLog(@"stream: %@", stream);

            [delegate cryptoServerRequestDidReceiveError:self];

            break;

        }

        default:

            break;

    }

}

- (void)createBlobAndSend {

    size_t sentBytes = 0;

    NSData * cryptoBlob = [self createBlob:self.peerName peerPublicKey:self.peerPublicKey];

    if (cryptoBlob) {

        sentBytes = [self sendData:cryptoBlob];

    } else {

        LOGGING_FACILITY(0, @"Something wrong with the building of the crypto blob.\n");

    }

    LOGGING_FACILITY1( sentBytes == [cryptoBlob length], @"Only sent %d bytes of crypto blob.", sentBytes );

    [self.ostr close];

    // Remove ourselves from the mutable container and thereby releasing ourselves.

    [delegate cryptoServerRequestDidFinish:self];

}

- (NSData *)receiveData {

    int len = 0;

    size_t lengthByte = 0;

    NSMutableData * retBlob = nil;

    len = [self.istr read:(uint8_t *)&lengthByte maxLength:sizeof(size_t)];

    LOGGING_FACILITY1( len == sizeof(size_t), @"Read failure errno: [%d]", errno );

    if (lengthByte <= kMaxMessageLength && len == sizeof(size_t)) {

        retBlob = [NSMutableData dataWithLength:lengthByte];

        len = [self.istr read:(uint8_t *)[retBlob mutableBytes] maxLength:lengthByte];

        LOGGING_FACILITY1( len == lengthByte, @"Read failure, after buffer errno: [%d]", errno );

        if (len != lengthByte) {

            retBlob = nil;

        }

    }

    return retBlob;

}

- (NSUInteger)sendData:(NSData *)outData {

    size_t len = 0;

    if (outData) {

        len = [outData length];

        if (len > 0) {

            size_t longSize = sizeof(size_t);

            NSMutableData * message = [[NSMutableData alloc] initWithCapacity:(len + longSize)];

            [message appendBytes:(const void *)&len length:longSize];

            [message appendData:outData];

            [self.ostr write:[message bytes] maxLength:[message length]];

            [message release];

        }

    }

    return len;

}

- (NSData *)createBlob:(NSString *)peer peerPublicKey:(NSData *)peerKey {

    NSData * message = nil;

    NSString * error = nil;

    CCOptions pad = 0;

    SecKeyRef peerPublicKeyRef = NULL;

    NSMutableDictionary * messageHolder = [[NSMutableDictionary alloc] init];

    NSData * symmetricKey = [[SecKeyWrapper sharedWrapper] getSymmetricKeyBytes];

    // Build the plain text.

    NSData * plainText = [NSData dataWithBytes:(const void *)kMessageBodyBytes length:(sizeof(kMessageBodyBytes)/sizeof(kMessageBodyBytes[0]))];

    // Acquire handle to public key.

    peerPublicKeyRef = [[SecKeyWrapper sharedWrapper] addPeerPublicKey:peer keyBits:peerKey];

    LOGGING_FACILITY( peerPublicKeyRef, @"Could not establish client handle to public key." );

    if (peerPublicKey) {

        // Add the public key.

        [messageHolder  setObject:[[SecKeyWrapper sharedWrapper] getPublicKeyBits]

                          forKey:[NSString stringWithUTF8String:(const char *)kPubTag]];

        // Add the signature to the message holder.     

        [messageHolder  setObject:[[SecKeyWrapper sharedWrapper] getSignatureBytes:plainText]

                          forKey:[NSString stringWithUTF8String:(const char *)kSigTag]];

        // Add the encrypted message.

        [messageHolder  setObject:[[SecKeyWrapper sharedWrapper] doCipher:plainText key:symmetricKey context:kCCEncrypt padding:&pad] 

                          forKey:[NSString stringWithUTF8String:(const char *)kMesTag]];

        // Add the padding PKCS#7 flag.

        [messageHolder  setObject:[NSNumber numberWithUnsignedInt:pad] 

                          forKey:[NSString stringWithUTF8String:(const char *)kPadTag]];

        // Add the wrapped symmetric key.

        [messageHolder  setObject:[[SecKeyWrapper sharedWrapper] wrapSymmetricKey:symmetricKey keyRef:peerPublicKeyRef]

                          forKey:[NSString stringWithUTF8String:(const char *)kSymTag]];

        message = [NSPropertyListSerialization dataFromPropertyList:messageHolder format:NSPropertyListBinaryFormat_v1_0 errorDescription:&error];

        // All done. Time to remove the public key from the keychain.

        [[SecKeyWrapper sharedWrapper] removePeerPublicKey:peer];

    } else {

        LOGGING_FACILITY(0, @"Could not establish client handle to public key.");

    }

    [messageHolder release];

    LOGGING_FACILITY( error == nil, error );

    [error release];

    return message;

}

- (void)dealloc {

    [istr removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

    [istr release];

    [ostr removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

    [ostr release];

    [peerName release];

    [peerPublicKey release];

    [super dealloc];

}

@end