Hi @ all,
I'm searching for the correct way to get the correct signing for my upload.
I get different results by using the command line and the Scratchpad. I'm using the Ooyala API (little bit modified, because it won't work in my Project) at the moment.
Is there a good example how to add the json-body to the signing? I think creating the NSData by using the
NSJSONSerialization with the option "NSJSONWritingPrettyPrinted" does not work very well for the signing purpose. I attached my code to this.
I'm using AFNetworking for the HTTPRequest with the generated Link of the OoyalaAPI.
Ooyala API:
#import "OoyalaAPI.h"
#import <CommonCrypto/CommonDigest.h>
#define ROUNDING_WINDOW 300
@implementation OoyalaAPI
/// <summary>
/// Takes in the necessary parameters to build a V2 signature for the Ooyala API
/// Use generateEncodedSignedURLWithHTTPMethod
/// </summary>
/// <param name="apiKey">
/// The API key for the Ooyala account to generate the URL for. You can find this key in the Developers tab in Backlot
/// </param>
/// <param name="secretKey">
/// The Secret key for the Ooyala account to generate the URL for. You can find this key in the Developers tab in Backlot
/// </param>
/// <param name="HTTPMethod">
/// The method to be used for the request. Possible values are: GET, POST, PUT, PATCH or DELETE
/// </param>
/// <param name="requestPath">
/// The path to use for the request
/// </param>
/// <param name="queryStringParameters">
/// A dictionary containing the list of parameters that will be included in the request.
/// </param>
/// <param name="requestBody">
/// An NSData containing the JSON representation of the data to be sent on the request. If there's no body for the request, just include an empty NSData object
/// </param>
/// <returns>
/// The signed URL to be used in the HTTP request.
/// </returns>
/*+ (NSString *)URLEncodeString:(NSString *)string
{
return [string stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];
}*/
+ (NSString *)URLEncodeString:(NSString *)string
{
CFTypeRef URLEncodedCFType = CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)string, NULL, (CFStringRef)@"!*'\"();:@&=+$,/?%#[]% ", kCFStringEncodingUTF8);
NSString *URLEncodedString = [NSString stringWithFormat:@"%@",URLEncodedCFType];
CFRelease(URLEncodedCFType);
return URLEncodedString;
}
+ (NSString *)generateEncodedSignatureWithHTTPMethod:(NSString *)HTTPMethod requestPath:(NSString *)requestPath queryStringParameters:(NSDictionary *)queryStringParameters secretKey:(NSString *)secretKey apiKey:(NSString *)apiKey andRequestBody:(NSData *)requestBody
{
//
// Generate stringToSign
//
//Concatenate first parameters to stringToSign
NSString *stringToSign = [NSString stringWithFormat:@"%@%@%@",secretKey,HTTPMethod,requestPath];
//Generate mutable dictionary for parameters
NSMutableDictionary *parametersDictionary = [NSMutableDictionary dictionaryWithDictionary:queryStringParameters];
//Expires
//Generate and add expires parameter if not already present
//Default expires time: 5min = 300s
if(![parametersDictionary objectForKey:@"expires"]){
NSNumber *expiresWindow = [NSNumber numberWithInt:300];
NSUInteger timestamp = (long)[[NSDate date] timeIntervalSince1970] + [expiresWindow intValue];
timestamp += [[NSNumber numberWithInt:ROUNDING_WINDOW] intValue] - (timestamp % [[NSNumber numberWithInt:ROUNDING_WINDOW] intValue] );
[parametersDictionary setValue:[NSString stringWithFormat:@"%lu", (unsigned long)timestamp] forKey:@"expires"];
}
//Add api_key parameter
[parametersDictionary setValue:[NSString stringWithFormat:@"%@", apiKey] forKey:@"api_key"];
//Sort parameters and append to stringToSign
NSArray *keys = [[parametersDictionary allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
for (NSUInteger i = 0; i < [keys count]; i++) {
NSString *key = [keys objectAtIndex:i];
NSString *value = [parametersDictionary objectForKey:key];
stringToSign = [stringToSign stringByAppendingFormat:@"%@=%@", key, value];
}
//Append Body
NSString *requestBodyString = [[NSString alloc] initWithData:requestBody encoding:NSUTF8StringEncoding];
stringToSign = [stringToSign stringByAppendingFormat:@"%@",requestBodyString];
//
// Generate signature from stringToSign
//
unsigned char hashedChars[32];
NSUInteger i;
//Generate SHA-256 in Base64
CC_SHA256([stringToSign UTF8String], [stringToSign lengthOfBytesUsingEncoding:NSUTF8StringEncoding], hashedChars);
NSData *hashedData = [NSData dataWithBytes:hashedChars length:32];
NSString *signature = [hashedData base64EncodedStringWithOptions:0];
//Truncate signature to 43 characters
signature = [signature substringToIndex:(NSUInteger)43];
//Remove from signature trailing = signs
for (i = [signature length] - 1; [signature characterAtIndex:i] == '='; i = [signature length] - 1) {
signature = [signature substringToIndex:i];
}
//URL-encode signature
return [OoyalaAPI URLEncodeString:signature];
}
+ (NSURL *)generateEncodedSignedURLWithHTTPMethod:(NSString *)HTTPMethod requestPath:(NSString *)requestPath queryStringParameters:(NSDictionary *)queryStringParameters apiKey:(NSString *)apiKey secretKey:(NSString *)secretKey andRequestBody:(NSData *)requestBody
{
//Append first parts of URLString
NSString *URLString = [NSString stringWithFormat:@"%@%@",@"https://api.ooyala.com",requestPath];
/**
* Process queryStringParameters
*/
//Generate mutable dictionary for parameters
NSMutableDictionary *parametersDictionary = [NSMutableDictionary dictionaryWithDictionary:queryStringParameters];
//Expires
//Generate and add expires parameter if not already present
//Default expires time: 5min = 300s
if(![parametersDictionary objectForKey:@"expires"]){
NSNumber *expiresWindow = [NSNumber numberWithInt:15];
NSUInteger timestamp = (long)[[NSDate date] timeIntervalSince1970] + [expiresWindow intValue];
timestamp += [[NSNumber numberWithInt:ROUNDING_WINDOW] intValue] - (timestamp % [[NSNumber numberWithInt:ROUNDING_WINDOW] intValue] );
[parametersDictionary setValue:[NSString stringWithFormat:@"%lu", (unsigned long)timestamp] forKey:@"expires"];
}
//Add api_key parameter
[parametersDictionary setValue:[NSString stringWithFormat:@"%@", apiKey] forKey:@"api_key"];
//Sort parameters and append to URLString
NSArray *keys = [[parametersDictionary allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
for (NSUInteger i = 0; i < [keys count]; i++) {
NSString *key = [keys objectAtIndex:i];
NSString *value = [parametersDictionary objectForKey:key];
NSString *format = (i==0)?@"?%@=%@":@"&%@=%@";
URLString = [URLString stringByAppendingFormat:format, [OoyalaAPI URLEncodeString:key], [OoyalaAPI URLEncodeString:value]];
}
//Append the signature
URLString = [URLString stringByAppendingFormat:@"&signature=%@",[self generateEncodedSignatureWithHTTPMethod:HTTPMethod requestPath:requestPath queryStringParameters:queryStringParameters secretKey:secretKey apiKey:apiKey andRequestBody:requestBody]];
return [NSURL URLWithString:URLString];
}
@endAnd my function to call the API:
// Ooyala Account defines
#define OoyalaAPIKey @"OoyalaAPIKey"
#define OoyalaSecret @"OoyalaSecret"
#define videoUploadSize 100000
/*
The Ooyala Backend Connection for video up- and download
*/
#pragma mark - Ooyala Backend
+(void)requestSignedVideoURL:(Video *)video {
// Build the attributes for the post request
NSMutableDictionary *parameter = [[NSMutableDictionary alloc] init];
[parameter setValue:video.fileName forKey:@"name"]; //todo
[parameter setValue:video.fileName forKey:@"file_name"];
[parameter setValue:@"video" forKey:@"asset_type"];
[parameter setValue:[NSString stringWithFormat:@"%d", video.fileSize] forKey:@"file_size"];
[parameter setValue:[NSString stringWithFormat:@"%i", videoUploadSize] forKey:@"chunk_size"];
// Perform the request to the ooyala backend
NSError *error = nil;
NSData *jsonParameters = [NSJSONSerialization dataWithJSONObject:parameter options:0 error:&error];
NSURL *finalURL = [OoyalaAPI generateEncodedSignedURLWithHTTPMethod:@"POST" requestPath:@"/v2/assets" queryStringParameters:nil apiKey:OoyalaAPIKey secretKey:OoyalaSecret andRequestBody:jsonParameters];
// ... Sending the Request by using AFNetworking and the configured httpSessionManager as a POST method ...
}
Looking forward for some help!
Cheers!
