From 16506b6d8bd205931b60cded82a13a318c10a30b Mon Sep 17 00:00:00 2001
From: Jason Rhinelander <jason@imaginary.ca>
Date: Wed, 25 Oct 2023 17:14:54 -0300
Subject: [PATCH] Default libcrypt to whether or not we find it

Also deliberately don't provide the function at all if we aren't
compiled with libcrypt so that we can't link if we try to call it when
not available.
---
 external/CMakeLists.txt | 5 ++++-
 llarp/crypto/crypto.cpp | 6 ++----
 llarp/service/auth.cpp  | 2 ++
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index f901be4c3..e8eca96e4 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -139,7 +139,10 @@ endif()
 set(default_libcrypt OFF)
 
 if(LINUX AND NOT STATIC_LINK)
-  set(default_libcrypt ON)
+  pkg_check_modules(LIBCRYPT libcrypt IMPORTED_TARGET)
+  if(LIBCRYPTO_FOUND)
+      set(default_libcrypt ON)
+  endif()
 endif()
 if(MACOS)
   set(default_libcrypt ON)
diff --git a/llarp/crypto/crypto.cpp b/llarp/crypto/crypto.cpp
index 81b9cd57d..f8a61535a 100644
--- a/llarp/crypto/crypto.cpp
+++ b/llarp/crypto/crypto.cpp
@@ -499,13 +499,11 @@ namespace llarp
     crypto_kem_keypair(d + PQ_SECRETKEYSIZE, d);
   }
 
+#ifdef HAVE_CRYPT
   bool
   crypto::check_passwd_hash(std::string pwhash, std::string challenge)
   {
-    (void)pwhash;
-    (void)challenge;
     bool ret = false;
-#ifdef HAVE_CRYPT
     auto pos = pwhash.find_last_of('$');
     auto settings = pwhash.substr(0, pos);
     crypt_data data{};
@@ -514,9 +512,9 @@ namespace llarp
       ret = ptr == pwhash;
     }
     sodium_memzero(&data, sizeof(data));
-#endif
     return ret;
   }
+#endif
 
   const byte_t*
   seckey_topublic(const SecretKey& sec)
diff --git a/llarp/service/auth.cpp b/llarp/service/auth.cpp
index b5a6c97e8..17fbda0cb 100644
--- a/llarp/service/auth.cpp
+++ b/llarp/service/auth.cpp
@@ -125,7 +125,9 @@ namespace llarp::service
         case AuthFileType::eAuthFilePlain:
           return hash == challenge;
         case AuthFileType::eAuthFileHashes:
+#ifdef HAVE_CRYPT
           return crypto::check_passwd_hash(std::move(hash), std::move(challenge));
+#endif
         default:
           return false;
       }