TumblrXAuth

// TumblrXAuth
//
// Created by Eric Johnson on 08/27/2010.
// Copyright 2010 Eric Johnson. All rights reserved.
//
// Heavily modified by HT154 on 06/15/2012.
//
// Permission is given to use this source code file, free of charge, in any
// project, commercial or otherwise, entirely at your risk, with the condition
// that any redistribution (in part or whole) of source code must retain
// this copyright and permission notice. Attribution in compiled projects is
// appreciated but not required.

#import <Foundation/Foundation.h>
#import "JSONKit.h"
#include <CommonCrypto/CommonHMAC.h>
#import "NSData+Base64.h"

@interface NSString (URLEncode)
- (NSString *)encodeForURL;
- (NSString *)encodeForURLReplacingSpacesWithPlus;
- (NSString *)decodeFromURL;
@end

@interface NSData (URLEncode)
- (NSString *)encodeForURL;
- (NSString *)stringWithoutURLEncoding;
- (NSString *)encodeForOauthBaseString;
@end

@class TumblrXAuth;

@protocol TumblrXAuthDelegate <NSObject>
@optional
-(void)tumblrXAuthAuthorizationDidFail:(TumblrXAuth *)tumblrXAuth error:(NSError *)error;
-(void)tumblrXAuthDidAuthorize:(TumblrXAuth *)tumblrXAuth;
-(void)tumblrXAuthDidFail:(TumblrXAuth *)tumblrXAuth error:(NSError *)error;
-(void)tumblrXAuthDidRespond:(TumblrXAuth *)tumblrXAuth response:(NSString *)response;
@end

typedef enum {
	TumblrXAuthStateDefault,
	TumblrXAuthStateAuthorize,
	TumblrXAuthStateAPI,
} TumblrXAuthState;

@interface TumblrXAuth : NSObject {
	NSString *nonce;
	NSString *timestamp;
	NSString *consumerKey;
	NSString *password;
	NSString *username;
	NSString *consumerSecret;
	NSString *token;
	NSString *tokenSecret;
	NSMutableData * data;
	TumblrXAuthState state;
	id<TumblrXAuthDelegate> delegate;
	NSDictionary *currentParams;
	NSString *tumblrURL;
	NSString *method;
}
@property (nonatomic,copy) NSString * consumerKey;
@property (nonatomic,copy) NSString * password;
@property (nonatomic,copy) NSString * username;
@property (nonatomic,copy) NSString * consumerSecret;
@property (nonatomic,copy) NSString * token; //oauth_token
@property (nonatomic,copy) NSString * tokenSecret; //oauth_token_secret
@property (nonatomic,assign) id<TumblrXAuthDelegate> delegate;
-(void)authorize;
-(id)initWithDelegate:(id<TumblrXAuthDelegate>)aDelegate consumerKey:(NSString *)ck consumerSecret:(NSString *)cs tokenKey:(NSString *)tk tokenSecret:(NSString *)ts;
-(void)sendOAuthRequestWithURL:(NSString *)url method:(NSString *)httpMethod parameters:(NSDictionary *)arguments;
-(void)sendAPIKeyRequestWithURL:(NSString *)url parameters:(NSDictionary *)arguments;

- (NSString *) nonce;

@end

@implementation NSString (URLEncode)
- (NSString *)encodeForURL{
	const CFStringRef legalURLCharactersToBeEscaped = CFSTR("!*'();:@&=+$,/?#[]<>\"{}|\\`^% ");
	return [NSMakeCollectable(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)self, NULL, legalURLCharactersToBeEscaped, kCFStringEncodingUTF8)) autorelease];
}

- (NSString *)encodeForURLReplacingSpacesWithPlus;{
	const CFStringRef legalURLCharactersToBeEscaped = CFSTR("!*'();:@&=$,/?#[]<>\"{}|\\`^% ");
	NSString *replaced = [self stringByReplacingOccurrencesOfString:@" " withString:@"+"];
	return [NSMakeCollectable(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)replaced, NULL, legalURLCharactersToBeEscaped, kCFStringEncodingUTF8)) autorelease];
}

- (NSString *)decodeFromURL{
	NSString *decoded = [NSMakeCollectable(CFURLCreateStringByReplacingPercentEscapesUsingEncoding(kCFAllocatorDefault, (CFStringRef)self, CFSTR(""), kCFStringEncodingUTF8)) autorelease];
	return [decoded stringByReplacingOccurrencesOfString:@"+" withString:@" "];
}
@end

@implementation NSData (URLEncode)
- (NSString *) stringWithoutURLEncoding {
	NSString *hexDataDesc = [self description];
	hexDataDesc = [[hexDataDesc stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"<>"]] stringByReplacingOccurrencesOfString:@" " withString:@""];
	NSMutableString * newString = [NSMutableString string];	
	for (int x=0; x<[hexDataDesc length]; x+=2) {
		NSString *component = [hexDataDesc substringWithRange:NSMakeRange(x, 2)];
		int value = 0;
		sscanf([component cStringUsingEncoding:NSASCIIStringEncoding], "%x", &value);
		if((value <=46 && value >= 45) || (value <=57 && value >= 48) || (value <=90 && value >= 65) || (value == 95) || (value <=122 && value >= 97)){  //48-57, 65-90, 97-122
			[newString appendFormat:@"%c", (char)value];
		}else{
			[newString appendFormat:@"%%%@", [component uppercaseString]];
		}
	}
	NSString *aNewString = [newString stringByReplacingOccurrencesOfString:@"%20" withString:@"+"];
	return aNewString;
}

- (NSString *) encodeForURL {
	NSString *newString = [self stringWithoutURLEncoding];
	newString = [newString stringByReplacingOccurrencesOfString:@"+" withString:@"%20"];
	const CFStringRef legalURLCharactersToBeEscaped = CFSTR("!*'();:@&=+$,/?#[]<>\"{}|\\`^% ");	
	NSString *encodeForURLdString = [NSMakeCollectable(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)newString, NULL, legalURLCharactersToBeEscaped, kCFStringEncodingUTF8)) autorelease];
	return encodeForURLdString;
}

- (NSString *) encodeForOauthBaseString {
	NSString *newString = [self encodeForURL];
	newString =[newString stringByReplacingOccurrencesOfString:@"%257E" withString:@"~"];
	return newString;
}

@end

@interface TumblrXAuth ()
- (void) resetNonce;
- (void) resetTimestamp;
- (NSString *) timestamp;
- (NSString *) baseString;
- (NSString *) signature;
- (NSString *) authorizationHeader;
@end

@implementation TumblrXAuth

@synthesize consumerKey, password, username, consumerSecret, token, tokenSecret;
@synthesize delegate;

-(id)initWithDelegate:(id<TumblrXAuthDelegate>)aDelegate consumerKey:(NSString *)ck consumerSecret:(NSString *)cs tokenKey:(NSString *)tk tokenSecret:(NSString *)ts{
	if ((self = [super init])) {
		state = TumblrXAuthStateDefault;
		data = [[NSMutableData alloc] init];
		if(!ts){self.tokenSecret = @"";
		}else{self.tokenSecret = ts;}
		if(tk){self.token = tk;}
		if(ck){self.consumerKey = ck;}
		if(cs){self.consumerSecret = cs;}
		if(aDelegate){self.delegate = aDelegate;}
		method = @"GET";
	}
	return self;
}

-(id)init{
	return [self initWithDelegate:nil consumerKey:nil consumerSecret:nil tokenKey:nil tokenSecret:nil];
}

-(void)dealloc{
	[data release];
	[currentParams release];
	[super dealloc];
}
	
#pragma mark Authentication Methods

-(void)resetNonce{[nonce release]; nonce = nil;}
-(void)resetTimestamp{[timestamp release]; timestamp = nil;}
-(NSString *)nonce{if (nonce == nil){nonce = [[NSString stringWithFormat:@"%d", arc4random()] retain];} return nonce;}
-(NSString *)timestamp{if (timestamp == nil){timestamp = [[NSString stringWithFormat:@"%d", (int)(((float)([[NSDate date] timeIntervalSince1970])) + 0.5)] retain];} return timestamp;}

-(NSString *)signature{
	NSString * secret = [NSString stringWithFormat:@"%@&%@", self.consumerSecret, self.tokenSecret];

	NSData * secretData = [secret dataUsingEncoding:NSUTF8StringEncoding];
	NSData * baseData = [self.baseString dataUsingEncoding:NSUTF8StringEncoding];
	
	//uint8_t digest[CC_SHA1_DIGEST_LENGTH] = {0};
	uint8_t digest[20] = {0};
	CCHmac(kCCHmacAlgSHA1, secretData.bytes, secretData.length, baseData.bytes, baseData.length, digest);
	//NSData * signatureData = [NSData dataWithBytes:digest length:CC_SHA256_DIGEST_LENGTH];
	NSData * signatureData = [NSData dataWithBytes:digest length:20];
	return [signatureData base64EncodedString];
}

-(NSString *)authorizationHeader{
	NSArray * keysAndValues = [NSArray arrayWithObjects:
		[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_nonce", [self.nonce encodeForURL]],
		[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_signature_method", [[NSString stringWithString:@"HMAC-SHA1"] encodeForURL]],
		[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_timestamp", [self.timestamp encodeForURL]],
		[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_consumer_key", [self.consumerKey encodeForURL]],
		[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_signature", [self.signature encodeForURL]],
		[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_version", [[NSString stringWithString:@"1.0"] encodeForURL]],
		nil];
	if (state == TumblrXAuthStateAPI && self.token && [self.token length] > 0)
		keysAndValues = [keysAndValues arrayByAddingObject:[NSString stringWithFormat:@"%@=\"%@\"", @"oauth_token", [self.token encodeForURL]]];
	return [NSString stringWithFormat:@"OAuth %@", [keysAndValues componentsJoinedByString:@", "]];
}

-(void)authorize{
	//send POST to https://www.tumblr.com/oauth/access_token with parameters: x_auth_username, x_auth_password, x_auth_mode

	[self resetTimestamp];
	[self resetNonce];
	
	state = TumblrXAuthStateAuthorize;

	[tumblrURL release];
	tumblrURL = [[NSString stringWithString:@"https://www.tumblr.com/oauth/access_token"] retain];
	NSMutableURLRequest* postRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:tumblrURL]];
	[postRequest setHTTPMethod: @"POST"];
	method = @"POST";
	NSArray * parameterArray = [NSArray arrayWithObjects:
		[NSString stringWithFormat:@"%@=%@", @"x_auth_mode", @"client_auth"],
		[NSString stringWithFormat:@"%@=%@", @"x_auth_password", [self.password encodeForURL]],
		[NSString stringWithFormat:@"%@=%@", @"x_auth_username", [self.username encodeForURL]],
		nil];
	[postRequest setHTTPBody:[[parameterArray componentsJoinedByString:@"&"] dataUsingEncoding:NSUTF8StringEncoding]];
	[postRequest addValue:self.authorizationHeader forHTTPHeaderField:@"Authorization"];

	[data setLength:0];
	[NSURLConnection connectionWithRequest:postRequest delegate:self];
}

-(NSString *)baseString{
	//method&url&parameters
	NSString * url = nil;
	url = [tumblrURL encodeForURL];

	NSString * parameters;

	NSString * oauth_consumer_key = [self.consumerKey encodeForURL];
	NSString * oauth_nonce = [self.nonce encodeForURL];
	NSString * oauth_signature_method = [[NSString stringWithString:@"HMAC-SHA1"] encodeForURL];
	NSString * oauth_timestamp = [self.timestamp encodeForURL];
	NSString * oauth_version = [[NSString stringWithString:@"1.0"] encodeForURL];
	NSString * x_auth_mode = [[NSString stringWithString:@"client_auth"] encodeForURL];
	NSString * x_auth_password = [self.password encodeForURL];
	NSString * x_auth_username = [self.username encodeForURL];

	NSArray * params = [NSArray arrayWithObjects:
		[NSString stringWithFormat:@"%@%%3D%@", @"oauth_consumer_key", oauth_consumer_key],
		[NSString stringWithFormat:@"%@%%3D%@", @"oauth_nonce", oauth_nonce],
		[NSString stringWithFormat:@"%@%%3D%@", @"oauth_signature_method", oauth_signature_method],
		[NSString stringWithFormat:@"%@%%3D%@", @"oauth_timestamp", oauth_timestamp],
		[NSString stringWithFormat:@"%@%%3D%@", @"oauth_version", oauth_version],
		nil];
	if (state == TumblrXAuthStateAuthorize)
		params = [params arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:[NSString stringWithFormat:@"%@%%3D%@", @"x_auth_mode", x_auth_mode],
			[NSString stringWithFormat:@"%@%%3D%@", @"x_auth_password", [x_auth_password encodeForURL]],
			[NSString stringWithFormat:@"%@%%3D%@", @"x_auth_username", [x_auth_username encodeForURL]],
			nil]];
	if (state == TumblrXAuthStateAPI){
		params = [params arrayByAddingObject:[NSString stringWithFormat:@"%@%%3D%@", @"oauth_token", [self.token encodeForURL]]];
		if(currentParams){
			for(id key in currentParams){
				params = [params arrayByAddingObject:[NSString stringWithFormat:@"%@%%3D%@", key,[[[currentParams objectForKey:key] encodeForURL] encodeForURL]]];
			}
		}
	}
	//sort paramaters alphabetically
	params = [[params sortedArrayUsingSelector:@selector(compare:)] retain];
	
	parameters = [params componentsJoinedByString:@"%26"];

	NSArray *baseComponents = [NSArray arrayWithObjects:method, url, parameters, nil];
	NSString *baseString = [baseComponents componentsJoinedByString:@"&"];
	return baseString;
}

#pragma mark API Assists

-(void)sendOAuthRequestWithURL:(NSString *)url method:(NSString *)httpMethod parameters:(NSDictionary *)arguments{
	
	[self resetTimestamp];
	[self resetNonce];
	
	state = TumblrXAuthStateAPI;
	currentParams = arguments;
	NSMutableArray * parameterArray = [NSMutableArray array];
	if(arguments){for(id key in arguments){[parameterArray addObject:[NSString stringWithFormat:@"%@=%@", [key encodeForURL],[[arguments objectForKey:key] encodeForURL]]];}}
	[tumblrURL release];
	tumblrURL = [[NSString stringWithString:url] retain];
	if([httpMethod isEqual:@"GET"]){
		url = [url stringByAppendingFormat:@"?%@",[parameterArray componentsJoinedByString:@"&"]];
	}
	NSMutableURLRequest* postRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url]];
	
	[postRequest setHTTPMethod:httpMethod];
	method = httpMethod;
	
	if([httpMethod isEqual:@"POST"]){
		[postRequest setHTTPBody:[[parameterArray componentsJoinedByString:@"&"] dataUsingEncoding:NSUTF8StringEncoding]];
	}
	[postRequest addValue:self.authorizationHeader forHTTPHeaderField:@"Authorization"];
	[postRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-type"];
	[data setLength:0];
	
	[NSURLConnection connectionWithRequest:postRequest delegate:self];
}

-(void)sendAPIKeyRequestWithURL:(NSString *)url parameters:(NSDictionary *)arguments{
	state = TumblrXAuthStateAPI;
	NSMutableString *tURL = [NSMutableString stringWithCapacity:30];
	[tURL appendString:[NSString stringWithFormat:@"%@?api_key=%@",url,self.consumerKey]];
	if(arguments){
		for (id key in arguments){
			[tURL appendString:[NSString stringWithFormat:@"&%@=%@",key,[arguments objectForKey:key]]];
		}
	}
	NSMutableURLRequest *postRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:tURL]];
	[postRequest setHTTPMethod: @"GET"];
	[data setLength:0];
	[NSURLConnection connectionWithRequest:postRequest delegate:self];
}


#pragma mark NSURLConnection Delegate Methods

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
	if (state == TumblrXAuthStateAuthorize && delegate && [delegate respondsToSelector:@selector(tumblrXAuthAuthorizationDidFail:error:)])
		[delegate tumblrXAuthAuthorizationDidFail:self error:error];
	if (state == TumblrXAuthStateAPI && delegate && [delegate respondsToSelector:@selector(tumblrXAuthDidFail:error:)])
		[delegate tumblrXAuthDidFail:self error:error];
}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)newData{
	[data appendData:newData];
}

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
	if ([response respondsToSelector:@selector(statusCode)]) {
		NSInteger statusCode = [((NSHTTPURLResponse *)response) statusCode];
		if (statusCode >= 400) {
			[connection cancel];
			NSDictionary * errorInfo = [NSDictionary dictionaryWithObject:[NSString stringWithFormat:NSLocalizedString(@"Server returned status code %d",@""), statusCode] forKey:NSLocalizedDescriptionKey];
			NSError * statusError = [NSError errorWithDomain:@"HTTP Property Status Code" code:statusCode userInfo:errorInfo];
			[self connection:connection didFailWithError:statusError];
		}
	}
}

-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
	if (state == TumblrXAuthStateAuthorize) {
		NSString * response = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
		NSArray * parameters = [response componentsSeparatedByString:@"&"];
		NSMutableDictionary * dictionary = [NSMutableDictionary dictionary];
		for (NSString * parameter in parameters) {
			NSArray * keyAndValue = [parameter componentsSeparatedByString:@"="];
			if (keyAndValue == nil || [keyAndValue count] != 2)
				continue;
			NSString * key = [keyAndValue objectAtIndex:0];
			NSString * value = [keyAndValue lastObject];
			[dictionary setObject:value forKey:key];
		}
		if ([dictionary objectForKey:@"oauth_token_secret"])
			self.tokenSecret = [dictionary objectForKey:@"oauth_token_secret"];
		if ([dictionary objectForKey:@"oauth_token"])
			self.token = [dictionary objectForKey:@"oauth_token"];
		if (delegate && [delegate respondsToSelector:@selector(tumblrXAuthDidAuthorize:)])
			[delegate tumblrXAuthDidAuthorize:self];
	}else if (state == TumblrXAuthStateAPI) {
		if (delegate && [delegate respondsToSelector:@selector(tumblrXAuthDidRespond:response:)])
			[delegate tumblrXAuthDidRespond:self response:[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]];
	}
}

@end