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| 1 | +import Async |
| 2 | +import Crypto |
| 3 | + |
| 4 | +/// A PostgreSQL frontend client. |
| 5 | +public final class PostgreSQLConnection { |
| 6 | + /// Handles enqueued redis commands and responses. |
| 7 | + private let queueStream: QueueStream<PostgreSQLMessage, PostgreSQLMessage> |
| 8 | + |
| 9 | + /// If non-nil, will log queries. |
| 10 | + public var logger: PostgreSQLLogger? |
| 11 | + |
| 12 | + /// Creates a new Redis client on the provided data source and sink. |
| 13 | + init<Stream>(stream: Stream, on worker: Worker) where Stream: ByteStream { |
| 14 | + let queueStream = QueueStream<PostgreSQLMessage, PostgreSQLMessage>() |
| 15 | + |
| 16 | + let serializerStream = PostgreSQLMessageSerializer().stream(on: worker) |
| 17 | + let parserStream = PostgreSQLMessageParser().stream(on: worker) |
| 18 | + |
| 19 | + stream.stream(to: parserStream) |
| 20 | + .stream(to: queueStream) |
| 21 | + .stream(to: serializerStream) |
| 22 | + .output(to: stream) |
| 23 | + |
| 24 | + self.queueStream = queueStream |
| 25 | + } |
| 26 | + |
| 27 | + /// Sends `PostgreSQLMessage` to the server. |
| 28 | + func send(_ messages: [PostgreSQLMessage], onResponse: @escaping (PostgreSQLMessage) throws -> ()) -> Future<Void> { |
| 29 | + var error: Error? |
| 30 | + return queueStream.enqueue(messages) { message in |
| 31 | + switch message { |
| 32 | + case .readyForQuery: |
| 33 | + if let e = error { throw e } |
| 34 | + return true |
| 35 | + case .error(let e): error = e |
| 36 | + case .notice(let n): print(n) |
| 37 | + default: try onResponse(message) |
| 38 | + } |
| 39 | + return false // request until ready for query |
| 40 | + } |
| 41 | + } |
| 42 | + |
| 43 | + /// Sends `PostgreSQLMessage` to the server. |
| 44 | + func send(_ message: [PostgreSQLMessage]) -> Future<[PostgreSQLMessage]> { |
| 45 | + var responses: [PostgreSQLMessage] = [] |
| 46 | + return send(message) { response in |
| 47 | + responses.append(response) |
| 48 | + }.map(to: [PostgreSQLMessage].self) { |
| 49 | + return responses |
| 50 | + } |
| 51 | + } |
| 52 | + |
| 53 | + /// Authenticates the `PostgreSQLClient` using a username with no password. |
| 54 | + public func authenticate(username: String, database: String? = nil, password: String? = nil) -> Future<Void> { |
| 55 | + let startup = PostgreSQLStartupMessage.versionThree(parameters: [ |
| 56 | + "user": username, |
| 57 | + "database": database ?? username |
| 58 | + ]) |
| 59 | + var authRequest: PostgreSQLAuthenticationRequest? |
| 60 | + return queueStream.enqueue([.startupMessage(startup)]) { message in |
| 61 | + switch message { |
| 62 | + case .authenticationRequest(let a): |
| 63 | + authRequest = a |
| 64 | + return true |
| 65 | + default: throw PostgreSQLError(identifier: "auth", reason: "Unsupported message encountered during auth: \(message).", source: .capture()) |
| 66 | + } |
| 67 | + }.flatMap(to: Void.self) { |
| 68 | + guard let auth = authRequest else { |
| 69 | + throw PostgreSQLError(identifier: "authRequest", reason: "No authorization request / status sent.", source: .capture()) |
| 70 | + } |
| 71 | + |
| 72 | + let input: [PostgreSQLMessage] |
| 73 | + switch auth { |
| 74 | + case .ok: |
| 75 | + guard password == nil else { |
| 76 | + throw PostgreSQLError(identifier: "trust", reason: "No password is required", source: .capture()) |
| 77 | + } |
| 78 | + input = [] |
| 79 | + case .plaintext: |
| 80 | + guard let password = password else { |
| 81 | + throw PostgreSQLError(identifier: "password", reason: "Password is required", source: .capture()) |
| 82 | + } |
| 83 | + let passwordMessage = PostgreSQLPasswordMessage(password: password) |
| 84 | + input = [.password(passwordMessage)] |
| 85 | + case .md5(let salt): |
| 86 | + guard let password = password else { |
| 87 | + throw PostgreSQLError(identifier: "password", reason: "Password is required", source: .capture()) |
| 88 | + } |
| 89 | + guard let passwordData = password.data(using: .utf8) else { |
| 90 | + throw PostgreSQLError(identifier: "passwordUTF8", reason: "Could not convert password to UTF-8 encoded Data.", source: .capture()) |
| 91 | + } |
| 92 | + |
| 93 | + guard let usernameData = username.data(using: .utf8) else { |
| 94 | + throw PostgreSQLError(identifier: "usernameUTF8", reason: "Could not convert username to UTF-8 encoded Data.", source: .capture()) |
| 95 | + } |
| 96 | + |
| 97 | + let hasher = MD5() |
| 98 | + // pwdhash = md5(password + username).hexdigest() |
| 99 | + var passwordUsernameData = passwordData + usernameData |
| 100 | + hasher.update(sequence: &passwordUsernameData) |
| 101 | + hasher.finalize() |
| 102 | + guard let pwdhash = hasher.hash.hexString.data(using: .utf8) else { |
| 103 | + throw PostgreSQLError(identifier: "hashUTF8", reason: "Could not convert password hash to UTF-8 encoded Data.", source: .capture()) |
| 104 | + } |
| 105 | + hasher.reset() |
| 106 | + // hash = ′ md 5′ + md 5(pwdhash + salt ).hexdigest () |
| 107 | + var saltedData = pwdhash + salt |
| 108 | + hasher.update(sequence: &saltedData) |
| 109 | + hasher.finalize() |
| 110 | + let passwordMessage = PostgreSQLPasswordMessage(password: "md5" + hasher.hash.hexString) |
| 111 | + input = [.password(passwordMessage)] |
| 112 | + } |
| 113 | + |
| 114 | + return self.queueStream.enqueue(input) { message in |
| 115 | + switch message { |
| 116 | + case .error(let error): throw error |
| 117 | + case .readyForQuery: return true |
| 118 | + case .authenticationRequest: return false |
| 119 | + case .parameterStatus, .backendKeyData: return false |
| 120 | + default: throw PostgreSQLError(identifier: "authenticationMessage", reason: "Unexpected authentication message: \(message)", source: .capture()) |
| 121 | + } |
| 122 | + } |
| 123 | + } |
| 124 | + } |
| 125 | + |
| 126 | + /// Closes this client. |
| 127 | + public func close() { |
| 128 | + queueStream.close() |
| 129 | + } |
| 130 | +} |
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