Skip to content

Make password hashing fast #189

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 21, 2021
Merged

Make password hashing fast #189

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
45 changes: 41 additions & 4 deletions Sources/PostgresNIO/New/PSQLChannelHandler.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -357,16 +357,16 @@ final class PSQLChannelHandler: ChannelDuplexHandler {
switch mode {
case .md5(let salt):
let hash1 = (authContext.password ?? "") + authContext.username
let pwdhash = Insecure.MD5.hash(data: [UInt8](hash1.utf8)).hexdigest()
let pwdhash = Insecure.MD5.hash(data: [UInt8](hash1.utf8)).asciiHexDigest()

var hash2 = [UInt8]()
hash2.reserveCapacity(pwdhash.count + 4)
hash2.append(contentsOf: pwdhash.utf8)
hash2.append(contentsOf: pwdhash)
hash2.append(salt.0)
hash2.append(salt.1)
hash2.append(salt.2)
hash2.append(salt.3)
let hash = "md5" + Insecure.MD5.hash(data: hash2).hexdigest()
let hash = Insecure.MD5.hash(data: hash2).md5PrefixHexdigest()

try! self.encoder.encode(.password(.init(value: hash)))
context.writeAndFlush(self.wrapOutboundOut(self.encoder.flush()!), promise: nil)
Expand Down Expand Up @@ -552,3 +552,40 @@ extension AuthContext {
replication: .false)
}
}

private extension Insecure.MD5.Digest {

private static let lowercaseLookup: [UInt8] = [
UInt8(ascii: "0"), UInt8(ascii: "1"), UInt8(ascii: "2"), UInt8(ascii: "3"),
UInt8(ascii: "4"), UInt8(ascii: "5"), UInt8(ascii: "6"), UInt8(ascii: "7"),
UInt8(ascii: "8"), UInt8(ascii: "9"), UInt8(ascii: "a"), UInt8(ascii: "b"),
UInt8(ascii: "c"), UInt8(ascii: "d"), UInt8(ascii: "e"), UInt8(ascii: "f"),
]

func asciiHexDigest() -> [UInt8] {
var result = [UInt8]()
result.reserveCapacity(2 * Insecure.MD5Digest.byteCount)
for byte in self {
result.append(Self.lowercaseLookup[Int(byte >> 4)])
result.append(Self.lowercaseLookup[Int(byte & 0x0F)])
}
return result
}

func md5PrefixHexdigest() -> String {
// TODO: The array should be stack allocated in the best case. But we support down to 5.2.
// Given that this method is called only on startup of a new connection, this is an
// okay tradeoff for now.
var result = [UInt8]()
result.reserveCapacity(3 + 2 * Insecure.MD5Digest.byteCount)
result.append(UInt8(ascii: "m"))
result.append(UInt8(ascii: "d"))
result.append(UInt8(ascii: "5"))

for byte in self {
result.append(Self.lowercaseLookup[Int(byte >> 4)])
result.append(Self.lowercaseLookup[Int(byte & 0x0F)])
}
return String(decoding: result, as: Unicode.UTF8.self)
}
}