Ios Epub字体损坏不起作用
我正在使用Swift 2为iOS创建EPUB 3阅读器 我目前面临的问题是字体混淆/字体损坏。我读过一篇教程,其中介绍了如何在Swift中实现这一点,并对其进行了一些修改,将其集成到我的项目中 当我将一个模糊的epub加载到我的应用程序中时,字体加载不正确,会退回到其他系统字体。当我加载一个具有相同字体但没有混淆的epub时,一切看起来都很好。显然,这意味着我的模糊代码有问题,但我一辈子都找不到错误 这是我的密码:Ios Epub字体损坏不起作用,ios,swift,fonts,epub,reader,Ios,Swift,Fonts,Epub,Reader,我正在使用Swift 2为iOS创建EPUB 3阅读器 我目前面临的问题是字体混淆/字体损坏。我读过一篇教程,其中介绍了如何在Swift中实现这一点,并对其进行了一些修改,将其集成到我的项目中 当我将一个模糊的epub加载到我的应用程序中时,字体加载不正确,会退回到其他系统字体。当我加载一个具有相同字体但没有混淆的epub时,一切看起来都很好。显然,这意味着我的模糊代码有问题,但我一辈子都找不到错误 这是我的密码: public struct Crypto { public func ob
public struct Crypto {
public func obfuscateFontIDPF(data:NSData, key:String) -> NSData {
let source = data
var destination = [UInt8]()
let shaKey = key.sha1()
let keyData = shaKey.utf8Array
var arr = [UInt8](count: source.length, repeatedValue: 0)
source.getBytes(&arr, length:source.length)
var outer = 0
while outer < 52 && arr.isEmpty == false {
var inner = 0
while inner < 20 && arr.isEmpty == false {
let byte = arr.removeAtIndex(0) //Assumes read advances file position
let sourceByte = byte
let keyByte = keyData[inner]
let obfuscatedByte = sourceByte ^ keyByte
destination.append(obfuscatedByte)
inner++
}
outer++
}
if arr.isEmpty == false {
while arr.isEmpty == false {
let byte = arr.removeAtIndex(0)
destination.append(byte)
}
}
let newData = NSData(bytes: &destination, length: destination.count*sizeof(UInt8))
return newData
}
}
extension String {
func sha1() -> String {
var selfAsSha1 = ""
if let data = self.dataUsingEncoding(NSUTF8StringEncoding)
{
var digest = [UInt8](count: Int(CC_SHA1_DIGEST_LENGTH), repeatedValue: 0)
CC_SHA1(data.bytes, CC_LONG(data.length), &digest)
for index in 0..<CC_SHA1_DIGEST_LENGTH
{
selfAsSha1 += String(format: "%02x", digest[Int(index)])
}
}
return selfAsSha1
}
var utf8Array: [UInt8] {
return Array(utf8)
}
}
如果您看到错误可能在哪里,请告诉我。我找到了,下面是工作代码:
private func obfuscateData(data: NSData, key: String) -> NSData {
var destinationBytes = [UInt8]()
// Key needs to be SHA1 hash with length of exactly 20 chars
let hashedKeyBytes = generateHashedBytesFromString(key)
var sourceBytes = [UInt8](count: data.length, repeatedValue: 0)
data.getBytes(&sourceBytes, length: data.length)
var outerCount = 0
while outerCount < 52 && sourceBytes.isEmpty == false {
var innerCount = 0
while innerCount < 20 && sourceBytes.isEmpty == false {
let sourceByte = sourceBytes.removeAtIndex(0)
let keyByte = hashedKeyBytes[innerCount]
let obfuscatedByte = (sourceByte ^ keyByte)
destinationBytes.append(obfuscatedByte)
innerCount += 1
}
outerCount += 1
}
destinationBytes.appendContentsOf(sourceBytes)
let destinationData = NSData(bytes: &destinationBytes, length: destinationBytes.count*sizeof(UInt8))
sourceBytes.removeAll(keepCapacity: false)
destinationBytes.removeAll(keepCapacity: false)
return destinationData
}
/// Convert the key string to a SHA1 hashed Byte Array
private func generateHashedBytesFromString(string: String) -> [UInt8] {
var resultBytes = [UInt8]()
var hashedString = string.sha1()
for _ in 0.stride(to: hashedString.characters.count, by: 2) {
let character = "0x\(hashedString.returnTwoCharacters())"
resultBytes.append(UInt8(strtod(character, nil)))
}
return resultBytes
}
extension String {
func sha1() -> String {
var selfAsSha1 = ""
if let data = self.dataUsingEncoding(NSUTF8StringEncoding) {
var digest = [UInt8](count: Int(CC_SHA1_DIGEST_LENGTH), repeatedValue: 0)
CC_SHA1(data.bytes, CC_LONG(data.length), &digest)
for index in 0..<CC_SHA1_DIGEST_LENGTH {
selfAsSha1 += String(format: "%02x", digest[Int(index)])
}
}
return selfAsSha1
}
mutating func returnTwoCharacters() -> String {
var characters: String = ""
characters.append(self.removeAtIndex(startIndex))
characters.append(self.removeAtIndex(startIndex))
return characters
}
}
有趣的是,使用真正的加密AES和普通加密可能会快几个数量级。@zaph是的,不幸的是,不是我制定了Epub标准。而且,这只是法律上的保护,解压epub和提取字体非常容易。这样做只是为了合法地保护出版商。
private func obfuscateData(data: NSData, key: String) -> NSData {
var destinationBytes = [UInt8]()
// Key needs to be SHA1 hash with length of exactly 20 chars
let hashedKeyBytes = generateHashedBytesFromString(key)
var sourceBytes = [UInt8](count: data.length, repeatedValue: 0)
data.getBytes(&sourceBytes, length: data.length)
var outerCount = 0
while outerCount < 52 && sourceBytes.isEmpty == false {
var innerCount = 0
while innerCount < 20 && sourceBytes.isEmpty == false {
let sourceByte = sourceBytes.removeAtIndex(0)
let keyByte = hashedKeyBytes[innerCount]
let obfuscatedByte = (sourceByte ^ keyByte)
destinationBytes.append(obfuscatedByte)
innerCount += 1
}
outerCount += 1
}
destinationBytes.appendContentsOf(sourceBytes)
let destinationData = NSData(bytes: &destinationBytes, length: destinationBytes.count*sizeof(UInt8))
sourceBytes.removeAll(keepCapacity: false)
destinationBytes.removeAll(keepCapacity: false)
return destinationData
}
/// Convert the key string to a SHA1 hashed Byte Array
private func generateHashedBytesFromString(string: String) -> [UInt8] {
var resultBytes = [UInt8]()
var hashedString = string.sha1()
for _ in 0.stride(to: hashedString.characters.count, by: 2) {
let character = "0x\(hashedString.returnTwoCharacters())"
resultBytes.append(UInt8(strtod(character, nil)))
}
return resultBytes
}
extension String {
func sha1() -> String {
var selfAsSha1 = ""
if let data = self.dataUsingEncoding(NSUTF8StringEncoding) {
var digest = [UInt8](count: Int(CC_SHA1_DIGEST_LENGTH), repeatedValue: 0)
CC_SHA1(data.bytes, CC_LONG(data.length), &digest)
for index in 0..<CC_SHA1_DIGEST_LENGTH {
selfAsSha1 += String(format: "%02x", digest[Int(index)])
}
}
return selfAsSha1
}
mutating func returnTwoCharacters() -> String {
var characters: String = ""
characters.append(self.removeAtIndex(startIndex))
characters.append(self.removeAtIndex(startIndex))
return characters
}
}