2019-02-17 19:25:07 -06:00

129 lines
4.0 KiB
Forth

module PrayerTracker.Cookies
open Microsoft.AspNetCore.Http
open Newtonsoft.Json
open System
open System.Security.Cryptography
open System.IO
/// Cryptography settings to use for encrypting cookies
type CookieCrypto (key : string, iv : string) =
/// The key for the AES encryptor/decryptor
member __.Key = Convert.FromBase64String key
/// The initialization vector for the AES encryptor/decryptor
member __.IV = Convert.FromBase64String iv
/// Helpers for encrypting/decrypting cookies
[<AutoOpen>]
module private Crypto =
/// An instance of the cookie cryptography settings
let mutable crypto = CookieCrypto ("", "")
/// Encrypt a cookie payload
let encrypt (payload : string) =
use aes = new AesManaged ()
use enc = aes.CreateEncryptor (crypto.Key, crypto.IV)
use ms = new MemoryStream ()
use cs = new CryptoStream (ms, enc, CryptoStreamMode.Write)
use sw = new StreamWriter (cs)
sw.Write payload
sw.Close ()
(ms.ToArray >> Convert.ToBase64String) ()
/// Decrypt a cookie payload
let decrypt payload =
use aes = new AesManaged ()
use dec = aes.CreateDecryptor (crypto.Key, crypto.IV)
use ms = new MemoryStream (Convert.FromBase64String payload)
use cs = new CryptoStream (ms, dec, CryptoStreamMode.Read)
use sr = new StreamReader (cs)
sr.ReadToEnd ()
/// Encrypt a cookie
let encryptCookie cookie =
(JsonConvert.SerializeObject >> encrypt) cookie
/// Decrypt a cookie
let decryptCookie<'T> payload =
(decrypt >> JsonConvert.DeserializeObject<'T> >> box) payload
|> function null -> None | x -> Some (unbox<'T> x)
/// Accessor so that the crypto settings instance can be set during startup
let setCrypto c = Crypto.crypto <- c
/// Properties stored in the Small Group cookie
type GroupCookie =
{ /// The Id of the small group
[<JsonProperty "g">]
GroupId : Guid
/// The password hash of the small group
[<JsonProperty "p">]
PasswordHash : string
}
with
/// Convert these properties to a cookie payload
member this.toPayload () =
encryptCookie this
/// Create a set of strongly-typed properties from the cookie payload
static member fromPayload x =
try decryptCookie<GroupCookie> x with _ -> None
/// The payload for the timeout cookie
type TimeoutCookie =
{ /// The Id of the small group to which the user is currently logged in
[<JsonProperty "g">]
GroupId : Guid
/// The Id of the user who is currently logged in
[<JsonProperty "i">]
Id : Guid
/// The salted timeout hash to ensure that there has been no tampering with the cookie
[<JsonProperty "p">]
Password : string
/// How long this cookie is valid
[<JsonProperty "u">]
Until : int64
}
with
/// Convert this set of properties to the cookie payload
member this.toPayload () =
encryptCookie this
/// Create a strongly-typed timeout cookie from the cookie payload
static member fromPayload x =
try decryptCookie<TimeoutCookie> x with _ -> None
/// The payload for the user's "Remember Me" cookie
type UserCookie =
{ /// The Id of the group into to which the user is logged
[< JsonProperty "g">]
GroupId : Guid
/// The Id of the user
[<JsonProperty "i">]
Id : Guid
/// The user's password hash
[<JsonProperty "p">]
PasswordHash : string
}
with
/// Convert this set of properties to a cookie payload
member this.toPayload () =
encryptCookie this
/// Create the strongly-typed cookie properties from a cookie payload
static member fromPayload x =
try decryptCookie<UserCookie> x with _ -> None
/// Create a salted hash to use to validate the idle timeout key
let saltedTimeoutHash (c : TimeoutCookie) =
sha1Hash (sprintf "Prayer%ATracker%AIdle%dTimeout" c.Id c.GroupId c.Until)
/// Cookie options to push an expiration out by 100 days
let autoRefresh =
CookieOptions (Expires = Nullable<DateTimeOffset> (DateTimeOffset (DateTime.UtcNow.AddDays 100.)), HttpOnly = true)