From e7eb9ce662079df9f667e964807a1bc50f93d0fa Mon Sep 17 00:00:00 2001
From: Mike <mk6i@proton.me>
Date: Sun, 19 May 2024 21:41:49 -0400
Subject: [PATCH] export password hashing funcs and move to wire pkg

---
 state/user_store.go | 37 ++++---------------------------------
 wire/user.go        | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 33 deletions(-)
 create mode 100644 wire/user.go

diff --git a/state/user_store.go b/state/user_store.go
index 13f9c565..3e66b051 100644
--- a/state/user_store.go
+++ b/state/user_store.go
@@ -2,12 +2,10 @@ package state
 
 import (
 	"bytes"
-	"crypto/md5"
 	"database/sql"
 	"embed"
 	"errors"
 	"fmt"
-	"io"
 	"io/fs"
 	"net/http"
 	"time"
@@ -65,46 +63,19 @@ func (u *User) ValidateHash(md5Hash []byte) bool {
 // hash of the user's actual password. A roasted password is a XOR-obfuscated
 // form of the real password, intended to add a simple layer of security.
 func (u *User) ValidateRoastedPass(roastedPass []byte) bool {
-	var roastTable = [16]byte{
-		0xF3, 0x26, 0x81, 0xC4, 0x39, 0x86, 0xDB, 0x92,
-		0x71, 0xA3, 0xB9, 0xE6, 0x53, 0x7A, 0x95, 0x7C,
-	}
-	clearPass := make([]byte, len(roastedPass))
-	for i := range roastedPass {
-		clearPass[i] = roastedPass[i] ^ roastTable[i%len(roastTable)]
-	}
-	md5Hash := weakMD5PasswordHash(string(clearPass), u.AuthKey) // todo remove string conversion
+	clearPass := wire.RoastPassword(roastedPass)
+	md5Hash := wire.WeakMD5PasswordHash(string(clearPass), u.AuthKey) // todo remove string conversion
 	return bytes.Equal(u.WeakMD5Pass, md5Hash)
 }
 
 // HashPassword computes MD5 hashes of the user's password. It computes both
 // weak and strong variants and stores them in the struct.
 func (u *User) HashPassword(passwd string) error {
-	u.WeakMD5Pass = weakMD5PasswordHash(passwd, u.AuthKey)
-	u.StrongMD5Pass = strongMD5PasswordHash(passwd, u.AuthKey)
+	u.WeakMD5Pass = wire.WeakMD5PasswordHash(passwd, u.AuthKey)
+	u.StrongMD5Pass = wire.StrongMD5PasswordHash(passwd, u.AuthKey)
 	return nil
 }
 
-//goland:noinspection GoUnhandledErrorResult
-func weakMD5PasswordHash(pass, authKey string) []byte {
-	hash := md5.New()
-	io.WriteString(hash, authKey)
-	io.WriteString(hash, pass)
-	io.WriteString(hash, "AOL Instant Messenger (SM)")
-	return hash.Sum(nil)
-}
-
-//goland:noinspection GoUnhandledErrorResult
-func strongMD5PasswordHash(pass, authKey string) []byte {
-	top := md5.New()
-	io.WriteString(top, pass)
-	bottom := md5.New()
-	io.WriteString(bottom, authKey)
-	bottom.Write(top.Sum(nil))
-	io.WriteString(bottom, "AOL Instant Messenger (SM)")
-	return bottom.Sum(nil)
-}
-
 // SQLiteUserStore stores user feedbag (buddy list), profile, and
 // authentication credentials information in a SQLite database.
 type SQLiteUserStore struct {
diff --git a/wire/user.go b/wire/user.go
new file mode 100644
index 00000000..8346ee4d
--- /dev/null
+++ b/wire/user.go
@@ -0,0 +1,45 @@
+package wire
+
+import (
+	"crypto/md5"
+	"io"
+)
+
+// WeakMD5PasswordHash hashes password and authKey for AIM v3.5-v4.7.
+//
+//goland:noinspection ALL
+func WeakMD5PasswordHash(pass, authKey string) []byte {
+	hash := md5.New()
+	io.WriteString(hash, authKey)
+	io.WriteString(hash, pass)
+	io.WriteString(hash, "AOL Instant Messenger (SM)")
+	return hash.Sum(nil)
+}
+
+// StrongMD5PasswordHash hashes password and authKey for AIM v4.8+.
+//
+//goland:noinspection ALL
+func StrongMD5PasswordHash(pass, authKey string) []byte {
+	top := md5.New()
+	io.WriteString(top, pass)
+	bottom := md5.New()
+	io.WriteString(bottom, authKey)
+	bottom.Write(top.Sum(nil))
+	io.WriteString(bottom, "AOL Instant Messenger (SM)")
+	return bottom.Sum(nil)
+}
+
+// RoastPassword toggles password obfuscation using a roasting algorithm for
+// AIM v1.0-v3.0 auth. The first call obfuscates the password, and the second
+// call de-obfuscates the password, and so on.
+func RoastPassword(roastedPass []byte) []byte {
+	var roastTable = [16]byte{
+		0xF3, 0x26, 0x81, 0xC4, 0x39, 0x86, 0xDB, 0x92,
+		0x71, 0xA3, 0xB9, 0xE6, 0x53, 0x7A, 0x95, 0x7C,
+	}
+	clearPass := make([]byte, len(roastedPass))
+	for i := range roastedPass {
+		clearPass[i] = roastedPass[i] ^ roastTable[i%len(roastTable)]
+	}
+	return clearPass
+}