From 2f283bd4f148202f447c3e8fa8370863da7ada50 Mon Sep 17 00:00:00 2001
From: Richard Schneider <makaretu@gmail.com>
Date: Tue, 9 Apr 2019 14:53:13 +1200
Subject: [PATCH] feat: allow $IPFS_PASS to hold the passphrase (#81)

---
 doc/articles/envvars.md |  1 +
 src/IpfsEngine.cs       | 24 ++++++++++++++++++++++++
 test/IpfsEngineTest.cs  | 28 ++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/doc/articles/envvars.md b/doc/articles/envvars.md
index 5f5fd5e2..42799274 100644
--- a/doc/articles/envvars.md
+++ b/doc/articles/envvars.md
@@ -8,3 +8,4 @@ are used to control the behaviour of the library
 | HOME | The user's home directory |
 | HOMEPATH | same as `HOME` |
 | IPFS_PATH | The folder of the IPFS [repository](repository.md) |
+| IPFS_PASS | Contains the passphrase for the [key chain](key.md) |
diff --git a/src/IpfsEngine.cs b/src/IpfsEngine.cs
index 41b72a07..6e12bb77 100644
--- a/src/IpfsEngine.cs
+++ b/src/IpfsEngine.cs
@@ -36,6 +36,27 @@ public partial class IpfsEngine : ICoreApi, IService, IDisposable
         SecureString passphrase;
         ConcurrentBag<Func<Task>> stopTasks = new ConcurrentBag<Func<Task>>();
 
+        /// <summary>
+        ///   Creates a new instance of the <see cref="IpfsEngine"/> class
+        ///   with the IPFS_PASS environment variable.
+        /// </summary>
+        /// <remarks>
+        ///   Th passphrase must be in the IPFS_PASS environment variable.
+        /// </remarks>
+        public IpfsEngine()
+        {
+            var s = Environment.GetEnvironmentVariable("IPFS_PASS");
+            if (s == null)
+                throw new Exception("The IPFS_PASS environement variable is missing.");
+
+            passphrase = new SecureString();
+            foreach (var c in s)
+            {
+                this.passphrase.AppendChar(c);
+            }
+            Init();
+        }
+
         /// <summary>
         ///   Creates a new instance of the <see cref="IpfsEngine"/> class
         ///   with the specified passphrase.
@@ -64,6 +85,9 @@ public IpfsEngine(char[] passphrase)
         /// <param name="passphrase">
         ///   The password used to access the keychain.
         /// </param>
+        /// <remarks>
+        ///  A copy of the <paramref name="passphrase"/> is made.
+        /// </remarks>
         public IpfsEngine(SecureString passphrase)
         {
             this.passphrase = passphrase.Copy();
diff --git a/test/IpfsEngineTest.cs b/test/IpfsEngineTest.cs
index 5165e44c..6ba4827f 100644
--- a/test/IpfsEngineTest.cs
+++ b/test/IpfsEngineTest.cs
@@ -35,6 +35,27 @@ public async Task SecureString_Passphrase()
             await ipfs.KeyChain();
         }
 
+        [TestMethod]
+        public async Task IpfsPass_Passphrase()
+        {
+            var secret = "this is not a secure pass phrase";
+            var ipfs = new IpfsEngine(secret.ToCharArray());
+            ipfs.Options = TestFixture.Ipfs.Options;
+            await ipfs.KeyChain();
+
+            Environment.SetEnvironmentVariable("IPFS_PASS", secret);
+            try
+            {
+                ipfs = new IpfsEngine();
+                ipfs.Options = TestFixture.Ipfs.Options;
+                await ipfs.KeyChain();
+            }
+            finally
+            {
+                Environment.SetEnvironmentVariable("IPFS_PASS", null);
+            }
+        }
+
         [TestMethod]
         public async Task Wrong_Passphrase()
         {
@@ -51,6 +72,13 @@ public async Task Wrong_Passphrase()
             });
         }
 
+        [TestMethod]
+        [ExpectedException(typeof(Exception))]
+        public void IpfsPass_Missing()
+        {
+            var _ = new IpfsEngine();
+        }
+
         [TestMethod]
         public async Task Can_Start_And_Stop()
         {