moonlight-ios/Limelight/CryptoManager.m
2014-10-21 03:15:29 -04:00

237 lines
8.0 KiB
Objective-C

//
// CryptoManager.m
// Limelight
//
// Created by Diego Waxemberg on 10/14/14.
// Copyright (c) 2014 Limelight Stream. All rights reserved.
//
#import "CryptoManager.h"
#import "mkcert.h"
#import <AdSupport/ASIdentifierManager.h>
#include <openssl/aes.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/evp.h>
@implementation CryptoManager
static const int SHA1_DIGEST_LENGTH = 20;
static NSData* key = nil;
static NSData* cert = nil;
static NSData* p12 = nil;
- (NSData*) createAESKeyFromSalt:(NSData*)saltedPIN {
return [[self SHA1HashData:saltedPIN] subdataWithRange:NSMakeRange(0, 16)];
}
- (NSData*) SHA1HashData:(NSData*)data {
unsigned char sha1[SHA1_DIGEST_LENGTH];
SHA1([data bytes], [data length], sha1);
NSData* bytes = [NSData dataWithBytes:sha1 length:20];
return bytes;
}
- (NSData*) aesEncrypt:(NSData*)data withKey:(NSData*)key {
AES_KEY aesKey;
AES_set_encrypt_key([key bytes], 128, &aesKey);
int size = [self getEncryptSize:data];
unsigned char* buffer = malloc(size);
unsigned char* blockRoundedBuffer = calloc(1, size);
memcpy(blockRoundedBuffer, [data bytes], [data length]);
// AES_encrypt only encrypts the first 16 bytes so iterate the entire buffer
int blockOffset = 0;
while (blockOffset < size) {
AES_encrypt(blockRoundedBuffer + blockOffset, buffer + blockOffset, &aesKey);
blockOffset += 16;
}
NSData* encryptedData = [NSData dataWithBytes:buffer length:size];
free(buffer);
free(blockRoundedBuffer);
return encryptedData;
}
- (NSData*) aesDecrypt:(NSData*)data withKey:(NSData*)key {
AES_KEY aesKey;
AES_set_decrypt_key([key bytes], 128, &aesKey);
unsigned char* buffer = malloc([data length]);
// AES_decrypt only decrypts the first 16 bytes so iterate the entire buffer
int blockOffset = 0;
while (blockOffset < [data length]) {
AES_decrypt([data bytes] + blockOffset, buffer + blockOffset, &aesKey);
blockOffset += 16;
}
NSData* decryptedData = [NSData dataWithBytes:buffer length:[data length]];
free(buffer);
return decryptedData;
}
- (int) getEncryptSize:(NSData*)data {
// the size is the length of the data ceiling to the nearest 16 bytes
return (((int)[data length] + 15) / 16) * 16;
}
- (bool) verifySignature:(NSData *)data withSignature:(NSData*)signature andCert:(NSData*)cert {
const char* buffer = [cert bytes];
X509* x509;
BIO* bio = BIO_new(BIO_s_mem());
BIO_puts(bio, buffer);
x509 = PEM_read_bio_X509(bio, NULL, NULL, NULL);
BIO_free(bio);
if (!x509) {
fprintf(stderr, "unable to parse certificate in memory\n");
return NULL;
}
EVP_PKEY* pubKey = X509_get_pubkey(x509);
EVP_MD_CTX *mdctx = NULL;
mdctx = EVP_MD_CTX_create();
EVP_DigestVerifyInit(mdctx, NULL, EVP_sha256(), NULL, pubKey);
EVP_DigestVerifyUpdate(mdctx, [data bytes], [data length]);
int result = EVP_DigestVerifyFinal(mdctx, (unsigned char*)[signature bytes], [signature length]);
X509_free(x509);
EVP_PKEY_free(pubKey);
EVP_MD_CTX_destroy(mdctx);
return result > 0;
}
- (NSData *)signData:(NSData *)data withKey:(NSData *)key {
const char* buffer = [key bytes];
BIO* bio = BIO_new(BIO_s_mem());
BIO_puts(bio, buffer);
EVP_PKEY* pkey;
pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
BIO_free(bio);
if (!pkey) {
fprintf(stderr, "unable to parse private key in memory\n");
return NULL;
}
EVP_MD_CTX *mdctx = NULL;
mdctx = EVP_MD_CTX_create();
EVP_DigestSignInit(mdctx, NULL, EVP_sha256(), NULL, pkey);
EVP_DigestSignUpdate(mdctx, [data bytes], [data length]);
size_t slen;
EVP_DigestSignFinal(mdctx, NULL, &slen);
unsigned char* signature = malloc(slen);
int result = EVP_DigestSignFinal(mdctx, signature, &slen);
EVP_PKEY_free(pkey);
EVP_MD_CTX_destroy(mdctx);
if (result <= 0) {
free(signature);
return NULL;
}
NSData* signedData = [NSData dataWithBytes:signature length:slen];
free(signature);
return signedData;
}
// TODO: these three methods are almost identical, fix the copy-pasta
+ (NSData*) readCertFromFile {
if (cert == nil) {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *certFile = [documentsDirectory stringByAppendingPathComponent:@"client.crt"];
cert = [NSData dataWithContentsOfFile:certFile];
}
return cert;
}
+ (NSData*) readP12FromFile {
if (p12 == nil) {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *p12File = [documentsDirectory stringByAppendingPathComponent:@"client.p12"];
p12 = [NSData dataWithContentsOfFile:p12File];
}
return p12;
}
+ (NSData*) readKeyFromFile {
if (key == nil) {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *keyFile = [documentsDirectory stringByAppendingPathComponent:@"client.key"];
key = [NSData dataWithContentsOfFile:keyFile];
}
return key;
}
+ (bool) keyPairExists {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *keyFile = [documentsDirectory stringByAppendingPathComponent:@"client.key"];
NSString *p12File = [documentsDirectory stringByAppendingPathComponent:@"client.p12"];
NSString *certFile = [documentsDirectory stringByAppendingPathComponent:@"client.crt"];
bool keyFileExists = [[NSFileManager defaultManager] fileExistsAtPath:keyFile];
bool p12FileExists = [[NSFileManager defaultManager] fileExistsAtPath:p12File];
bool certFileExists = [[NSFileManager defaultManager] fileExistsAtPath:certFile];
return keyFileExists && p12FileExists && certFileExists;
}
+ (NSData *)getSignatureFromCert:(NSData *)cert {
const char* buffer = [cert bytes];
X509* x509;
BIO* bio = BIO_new(BIO_s_mem());
BIO_puts(bio, buffer);
x509 = PEM_read_bio_X509(bio, NULL, NULL, NULL);
if (!x509) {
fprintf(stderr, "unable to parse certificate in memory\n");
return NULL;
}
return [NSData dataWithBytes:x509->signature->data length:x509->signature->length];
}
+ (void) generateKeyPairUsingSSl {
if (![CryptoManager keyPairExists]) {
NSLog(@"Generating Certificate... ");
CertKeyPair certKeyPair = generateCertKeyPair();
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentsDirectory = [paths objectAtIndex:0];
NSString* certFile = [documentsDirectory stringByAppendingPathComponent:@"client.crt"];
NSString* keyPairFile = [documentsDirectory stringByAppendingPathComponent:@"client.key"];
NSString* p12File = [documentsDirectory stringByAppendingPathComponent:@"client.p12"];
//NSLog(@"Writing cert and key to: \n%@\n%@", certFile, keyPairFile);
saveCertKeyPair([certFile UTF8String], [p12File UTF8String], [keyPairFile UTF8String], certKeyPair);
freeCertKeyPair(certKeyPair);
}
}
+ (NSString*) getUniqueID {
// generate a UUID
NSUUID* uuid = [ASIdentifierManager sharedManager].advertisingIdentifier;
NSString* idString = [NSString stringWithString:[uuid UUIDString]];
// we need a 16byte hex-string so we take the last 17 characters
// and remove the '-' to get a 16 character string
NSMutableString* uniqueId = [NSMutableString stringWithString:[idString substringFromIndex:19]];
[uniqueId deleteCharactersInRange:NSMakeRange(4, 1)];
//NSLog(@"Unique ID: %@", uniqueId);
return [NSString stringWithString:uniqueId];
}
@end