Files
SQLWorkbench/WorkbenchReplacement/MySQLProtocol.swift.backup-20261016-164525
T
2026-10-16 17:03:05 +01:00

330 lines
16 KiB
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import Foundation
import CommonCrypto
import CoreFoundation
import Security
// Native MySQL wire protocol client. No external mysql executable is used.
// Initial scope: TCP, mysql_native_password and caching_sha2_password fast authentication.
struct MySQLWireError: LocalizedError {
let message: String
var errorDescription: String? { message }
}
private struct ByteCursor {
let bytes: [UInt8]
var offset = 0
mutating func take(_ n: Int) throws -> [UInt8] {
guard n >= 0, offset + n <= bytes.count else { throw MySQLWireError(message: "Malformed MySQL packet") }
defer { offset += n }
return Array(bytes[offset..<(offset+n)])
}
mutating func u8() throws -> UInt8 { try take(1)[0] }
mutating func u16() throws -> Int { let b = try take(2); return Int(b[0]) | (Int(b[1]) << 8) }
mutating func u32() throws -> Int { let b = try take(4); return Int(b[0]) | (Int(b[1]) << 8) | (Int(b[2]) << 16) | (Int(b[3]) << 24) }
mutating func nulString() throws -> String {
let start = offset
while offset < bytes.count && bytes[offset] != 0 { offset += 1 }
guard offset < bytes.count else { throw MySQLWireError(message: "Unterminated server string") }
let s = String(decoding: bytes[start..<offset], as: UTF8.self)
offset += 1
return s
}
mutating func lenInt() throws -> Int? {
let first = try u8()
switch first {
case 0xfb: return nil
case 0xfc: return try u16()
case 0xfd:
let b = try take(3); return Int(b[0]) | Int(b[1]) << 8 | Int(b[2]) << 16
case 0xfe:
let b = try take(8)
var v: UInt64 = 0
for (i, byte) in b.enumerated() { v |= UInt64(byte) << (8 * i) }
guard v <= UInt64(Int.max) else { throw MySQLWireError(message: "Field too large") }
return Int(v)
default: return Int(first)
}
}
mutating func lenString() throws -> String? {
guard let n = try lenInt() else { return nil }
return String(decoding: try take(n), as: UTF8.self)
}
}
private func le32(_ v: Int) -> [UInt8] { (0..<4).map { UInt8(truncatingIfNeeded: v >> ($0 * 8)) } }
private func sha1(_ data: [UInt8]) -> [UInt8] {
var result = [UInt8](repeating: 0, count: Int(CC_SHA1_DIGEST_LENGTH))
data.withUnsafeBytes { ptr in _ = CC_SHA1(ptr.baseAddress, CC_LONG(data.count), &result) }
return result
}
private func sha256(_ data: [UInt8]) -> [UInt8] {
var result = [UInt8](repeating: 0, count: Int(CC_SHA256_DIGEST_LENGTH))
data.withUnsafeBytes { ptr in _ = CC_SHA256(ptr.baseAddress, CC_LONG(data.count), &result) }
return result
}
private func authResponse(password: String, salt: [UInt8], plugin: String) throws -> [UInt8] {
if password.isEmpty { return [] }
let pwd = Array(password.utf8)
if plugin == "mysql_native_password" {
let first = sha1(pwd), second = sha1(sha1(pwd))
let last = sha1(salt + second)
return zip(first, last).map { $0 ^ $1 }
}
if plugin == "caching_sha2_password" {
let first = sha256(pwd), second = sha256(sha256(pwd))
let last = sha256(second + salt)
return zip(first, last).map { $0 ^ $1 }
}
throw MySQLWireError(message: "Authentication plugin \(plugin) is not yet supported")
}
// Parse an RSA SubjectPublicKeyInfo PEM supplied by MySQL. Security.framework
// expects the inner PKCS#1 RSAPublicKey DER for SecKeyCreateWithData.
private func mysqlRSAPublicKey(_ packet: [UInt8]) throws -> SecKey {
guard packet.first == 0x01 else {
throw MySQLWireError(message: "Expected caching_sha2_password public-key response")
}
let pem = String(decoding: packet.dropFirst(), as: UTF8.self)
let base64 = pem.components(separatedBy: .newlines)
.filter { !$0.hasPrefix("-----") }.joined()
.trimmingCharacters(in: .whitespacesAndNewlines)
guard let spki = Data(base64Encoded: base64) else {
throw MySQLWireError(message: "Invalid MySQL RSA public key")
}
let der = [UInt8](spki)
func length(_ index: inout Int) throws -> Int {
guard index < der.count else { throw MySQLWireError(message: "Invalid RSA DER length") }
let first = Int(der[index]); index += 1
if first < 128 { return first }
let bytes = first & 0x7f
guard bytes > 0, bytes <= 4, index + bytes <= der.count else {
throw MySQLWireError(message: "Invalid RSA DER length")
}
var value = 0
for _ in 0..<bytes { value = (value << 8) | Int(der[index]); index += 1 }
return value
}
func element(_ index: inout Int, tag: UInt8) throws -> Range<Int> {
guard index < der.count, der[index] == tag else {
throw MySQLWireError(message: "Invalid RSA DER element")
}
index += 1
let count = try length(&index)
guard count <= der.count - index else { throw MySQLWireError(message: "Truncated RSA DER") }
let range = index..<(index + count)
index += count
return range
}
var i = 0
let outer = try element(&i, tag: 0x30)
i = outer.lowerBound
_ = try element(&i, tag: 0x30) // AlgorithmIdentifier
let bits = try element(&i, tag: 0x03)
guard bits.count > 1, der[bits.lowerBound] == 0 else {
throw MySQLWireError(message: "Invalid RSA public key bit string")
}
let pkcs1 = Data(der[(bits.lowerBound + 1)..<bits.upperBound])
var error: Unmanaged<CFError>?
guard let key = SecKeyCreateWithData(pkcs1 as CFData, [
kSecAttrKeyType as String: kSecAttrKeyTypeRSA,
kSecAttrKeyClass as String: kSecAttrKeyClassPublic
] as CFDictionary, &error) else {
throw MySQLWireError(message: "Cannot import MySQL RSA public key: \(error?.takeRetainedValue().localizedDescription ?? "unknown error")")
}
return key
}
final class MySQLWireConnection {
private let input: InputStream
private let output: OutputStream
private var sequence: UInt8 = 0
private let maxPacket = 16_777_215
init(host: String, port: Int) throws {
guard (1...65535).contains(port) else { throw MySQLWireError(message: "Invalid port") }
var read: Unmanaged<CFReadStream>?
var write: Unmanaged<CFWriteStream>?
CFStreamCreatePairWithSocketToHost(nil, host as CFString, UInt32(port), &read, &write)
guard let r = read?.takeRetainedValue(), let w = write?.takeRetainedValue() else {
throw MySQLWireError(message: "Cannot create connection")
}
input = unsafeBitCast(r, to: InputStream.self)
output = unsafeBitCast(w, to: OutputStream.self)
input.open(); output.open()
// A CFStream may still be .opening immediately after open(). The
// first blocking read below waits for the server greeting.
if input.streamStatus == .error || output.streamStatus == .error {
throw MySQLWireError(message: input.streamError?.localizedDescription ?? output.streamError?.localizedDescription ?? "Could not open MySQL connection")
}
}
deinit { input.close(); output.close() }
private func readExact(_ count: Int) throws -> [UInt8] {
var buffer = [UInt8](repeating: 0, count: count)
var done = 0
while done < count {
let n = buffer.withUnsafeMutableBufferPointer { ptr -> Int in
guard let base = ptr.baseAddress else { return -1 }
return input.read(base.advanced(by: done), maxLength: count - done)
}
guard n > 0 else { throw MySQLWireError(message: input.streamError?.localizedDescription ?? "MySQL connection closed") }
done += n
}
return buffer
}
private func readPacket() throws -> [UInt8] {
let header = try readExact(4)
let count = Int(header[0]) | Int(header[1]) << 8 | Int(header[2]) << 16
sequence = header[3] &+ 1
return try readExact(count)
}
private func send(_ payload: [UInt8]) throws {
guard payload.count < maxPacket else { throw MySQLWireError(message: "Query exceeds initial client packet limit") }
let count = payload.count
let packet = [UInt8(count & 255), UInt8((count >> 8) & 255), UInt8((count >> 16) & 255), sequence] + payload
sequence = sequence &+ 1
var written = 0
while written < packet.count {
let n = packet.withUnsafeBufferPointer { ptr -> Int in
guard let base = ptr.baseAddress else { return -1 }
return output.write(base.advanced(by: written), maxLength: packet.count - written)
}
guard n > 0 else { throw MySQLWireError(message: output.streamError?.localizedDescription ?? "MySQL write failed") }
written += n
}
}
private func checkError(_ p: [UInt8]) throws {
guard p.first == 0xff else { return }
let details = String(decoding: p.dropFirst(3), as: UTF8.self)
throw MySQLWireError(message: "MySQL error: \(details)")
}
func authenticate(user: String, password: String, database: String) throws {
let hello = try readPacket()
var c = ByteCursor(bytes: hello)
let version = try c.u8()
guard version == 10 else { throw MySQLWireError(message: "Unsupported MySQL handshake") }
_ = try c.nulString()
_ = try c.u32()
let salt1 = try c.take(8)
_ = try c.u8()
let lower = try c.u16()
_ = try c.u8() // character set
_ = try c.u16() // status
let upper = try c.u16()
let capabilities = lower | (upper << 16)
let authLen = Int(try c.u8())
_ = try c.take(10)
let salt2 = try c.take(max(13, authLen - 8))
let salt = salt1 + salt2.prefix(max(0, authLen - 9))
let plugin = (try? c.nulString()) ?? "mysql_native_password"
// This initial implementation deliberately refuses cleartext remote credentials.
guard hostIsLoopback else { throw MySQLWireError(message: "Direct remote connections require TLS, which is not yet implemented. Use a local SSH tunnel.") }
// CLIENT_LONG_PASSWORD, LONG_FLAG, PROTOCOL_41, TRANSACTIONS,
// SECURE_CONNECTION and PLUGIN_AUTH. Do not set DEPRECATE_EOF.
let clientFlags = 0x00000001 | 0x00000004 | 0x00000200 | 0x00002000 | 0x00008000 | 0x00080000
let response = try authResponse(password: password, salt: Array(salt), plugin: plugin)
var body = le32(clientFlags & capabilities) + le32(16_777_216) + [UInt8(45)] + [UInt8](repeating: 0, count: 23)
body += Array(user.utf8) + [0, UInt8(response.count)] + response
body += Array(plugin.utf8) + [0]
try send(body)
var reply = try readPacket()
try checkError(reply)
var currentPlugin = plugin
var currentSalt = Array(salt)
if reply.first == 0xfe {
var switchCursor = ByteCursor(bytes: Array(reply.dropFirst()))
let newPlugin = try switchCursor.nulString()
let rawSalt = Array(reply.dropFirst(1 + newPlugin.utf8.count + 1))
let newSalt = rawSalt.last == 0 ? Array(rawSalt.dropLast()) : rawSalt
currentPlugin = newPlugin
currentSalt = newSalt
try send(authResponse(password: password, salt: newSalt, plugin: newPlugin))
reply = try readPacket()
try checkError(reply)
}
if reply.first == 0x01 {
guard currentPlugin == "caching_sha2_password", reply.count >= 2 else {
throw MySQLWireError(message: "Unsupported authentication continuation")
}
switch reply[1] {
case 0x03: // Fast authentication accepted; wait for OK.
reply = try readPacket()
case 0x04: // Full authentication required.
guard hostIsLoopback else {
throw MySQLWireError(message: "Remote full authentication requires TLS (not implemented). Use a trusted local SSH tunnel.")
}
if password.isEmpty {
try send([0])
} else {
// Request the server's RSA public key (0x02). This is
// intended ONLY for a trusted local loopback connection.
try send([0x02])
let keyPacket = try readPacket()
try checkError(keyPacket)
let key = try mysqlRSAPublicKey(keyPacket)
guard !currentSalt.isEmpty else {
throw MySQLWireError(message: "Missing MySQL authentication nonce")
}
var scrambled = Array(password.utf8) + [0]
for i in scrambled.indices { scrambled[i] ^= currentSalt[i % currentSalt.count] }
var rsaError: Unmanaged<CFError>?
guard let encrypted = SecKeyCreateEncryptedData(
key, .rsaEncryptionOAEPSHA1, Data(scrambled) as CFData, &rsaError
) as Data? else {
throw MySQLWireError(message: "MySQL RSA encryption failed: \(rsaError?.takeRetainedValue().localizedDescription ?? "unknown error")")
}
try send(Array(encrypted))
}
reply = try readPacket()
default:
throw MySQLWireError(message: "Unsupported caching_sha2_password response: \(reply[1])")
}
}
try checkError(reply)
guard reply.first == 0x00 else { throw MySQLWireError(message: "Authentication did not complete") }
if !database.isEmpty { _ = try query("USE `\(database.replacingOccurrences(of: "`", with: "``"))`") }
}
private var hostIsLoopback = false
func markHost(_ host: String) { hostIsLoopback = ["localhost", "127.0.0.1", "::1"].contains(host.lowercased()) }
func query(_ sql: String) throws -> QueryResult {
sequence = 0
try send([0x03] + Array(sql.utf8))
let first = try readPacket()
try checkError(first)
if first.first == 0x00 { return QueryResult(message: "Statement executed successfully") }
var c = ByteCursor(bytes: first)
guard let columnCount = try c.lenInt(), columnCount <= 4096 else { throw MySQLWireError(message: "Invalid column count") }
var names: [String] = []
for _ in 0..<columnCount {
var field = ByteCursor(bytes: try readPacket())
for _ in 0..<4 { _ = try field.lenString() }
names.append(try field.lenString() ?? "")
}
_ = try readPacket() // column EOF (initial protocol requires EOF)
var rows: [[String]] = []
while true {
let packet = try readPacket()
try checkError(packet)
if packet.first == 0xfe && packet.count < 9 { break }
var row = ByteCursor(bytes: packet)
var values: [String] = []
for _ in 0..<columnCount { values.append(try row.lenString() ?? "NULL") }
rows.append(values)
if rows.count > 100_000 { throw MySQLWireError(message: "Result exceeds 100,000 row safety limit") }
}
return QueryResult(columns: names, rows: rows, message: "\(rows.count) row(s)")
}
}
enum NativeMySQLRunner {
static func run(profile: ConnectionProfile, database: String, password: String, sql: String) async throws -> QueryResult {
try await Task.detached(priority: .userInitiated) {
let connection = try MySQLWireConnection(host: profile.host, port: profile.port)
connection.markHost(profile.host)
try connection.authenticate(user: profile.username, password: password, database: database)
return try connection.query(sql)
}.value
}
}