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URandom OSX - Linux no dependencies
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| // Source: https://github.com/vapor-community/random | |
| public protocol RandomProtocol { | |
| /// Get a random array of Bytes | |
| func bytes(count: Int) throws -> Bytes | |
| } | |
| // MARK: - Throwing getter methods | |
| extension RandomProtocol { | |
| /// Get a random Int8 | |
| public func makeInt8() throws -> Int8 { | |
| return Int8(bitPattern: try makeUInt8()) | |
| } | |
| /// Get a random UInt8 | |
| public func makeUInt8() throws -> UInt8 { | |
| return try bytes(count: 1)[0] | |
| } | |
| /// Get a random Int16 | |
| public func makeInt16() throws -> Int16 { | |
| return Int16(bitPattern: try makeUInt16()) | |
| } | |
| /// Get a random UInt16 | |
| public func makeUInt16() throws -> UInt16 { | |
| let random = try bytes(count: 2) | |
| return UnsafeRawPointer(random) | |
| .assumingMemoryBound(to: UInt16.self) | |
| .pointee | |
| } | |
| /// Get a random Int32 | |
| public func makeInt32() throws -> Int32 { | |
| return Int32(bitPattern: try makeUInt32()) | |
| } | |
| /// Get a random UInt32 | |
| public func makeUInt32() throws -> UInt32 { | |
| let random = try bytes(count: 4) | |
| return UnsafeRawPointer(random) | |
| .assumingMemoryBound(to: UInt32.self) | |
| .pointee | |
| } | |
| /// Get a random Int64 | |
| public func makeInt64() throws -> Int64 { | |
| return Int64(bitPattern: try makeUInt64()) | |
| } | |
| /// Get a random UInt64 | |
| public func makeUInt64() throws -> UInt64 { | |
| let random = try bytes(count: 8) | |
| return UnsafeRawPointer(random) | |
| .assumingMemoryBound(to: UInt64.self) | |
| .pointee | |
| } | |
| /// Get a random Int | |
| public func makeInt() throws -> Int { | |
| return Int(bitPattern: try makeUInt()) | |
| } | |
| /// Get a random UInt | |
| public func makeUInt() throws -> UInt { | |
| let random = try bytes(count: MemoryLayout<UInt>.size) | |
| return UnsafeRawPointer(random) | |
| .assumingMemoryBound(to: UInt.self) | |
| .pointee | |
| } | |
| } | |
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| // Adapted to work with both Linux and OSX | |
| // Source: https://github.com/vapor-community/random | |
| #if os(Linux) | |
| import Glibc | |
| #else | |
| import Darwin | |
| #endif | |
| public typealias Bytes = [UInt8] | |
| public typealias Byte = UInt8 | |
| /// URandom represents a file connection to /dev/urandom on Unix systems. | |
| /// /dev/urandom is a cryptographically secure random generator provided by the OS. | |
| public final class URandom: RandomProtocol { | |
| public enum Error: Swift.Error { | |
| case open(Int32) | |
| case read(Int32) | |
| } | |
| private let file: UnsafeMutablePointer<FILE> | |
| /// Initialize URandom | |
| public init(path: String) throws { | |
| guard let file = fopen(path, "rb") else { | |
| // The Random protocol doesn't allow init to fail, so we have to | |
| // check whether /dev/urandom was successfully opened here | |
| throw Error.open(errno) | |
| } | |
| self.file = file | |
| } | |
| deinit { | |
| fclose(file) | |
| } | |
| private func read(numBytes: Int) throws -> [Int8] { | |
| // Initialize an empty array with space for numBytes bytes | |
| var bytes = [Int8](repeating: 0, count: numBytes) | |
| guard fread(&bytes, 1, numBytes, file) == numBytes else { | |
| // If the requested number of random bytes couldn't be read, | |
| // we need to throw an error | |
| throw Error.read(errno) | |
| } | |
| return bytes | |
| } | |
| /// Get a random array of Bytes | |
| public func bytes(count: Int) throws -> Bytes { | |
| return try read(numBytes: count).map({ Byte(bitPattern: $0) }) | |
| } | |
| } | |
| extension URandom { | |
| public convenience init() throws { | |
| try self.init(path: "/dev/urandom") | |
| } | |
| } |
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