From 2769e43f61d827e1b8fe46257450986d76319243 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kasper=20Ga=C5=82kowski?= <kpg@posteo.net>
Date: Fri, 8 Apr 2022 19:38:43 +0200
Subject: [PATCH] assert hash types for Git and Mercurial

---
 src/libfetchers/git.cc       | 8 ++++++++
 src/libfetchers/mercurial.cc | 9 +++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/libfetchers/git.cc b/src/libfetchers/git.cc
index d75c5d3ae..220442479 100644
--- a/src/libfetchers/git.cc
+++ b/src/libfetchers/git.cc
@@ -189,8 +189,16 @@ struct GitInputScheme : InputScheme
         if (submodules) cacheType += "-submodules";
         if (allRefs) cacheType += "-all-refs";
 
+        auto checkHashType = [&](const std::optional<Hash> & hash)
+        {
+            if (hash.has_value() && !(hash->type == htSHA1 || hash->type == htSHA256))
+                throw Error("Hash '%s' is not supported by Git. Supported types are sha1 and sha256.", hash->to_string(Base16, true));
+        };
+
         auto getLockedAttrs = [&]()
         {
+            checkHashType(input.getRev());
+
             return Attrs({
                 {"type", cacheType},
                 {"name", name},
diff --git a/src/libfetchers/mercurial.cc b/src/libfetchers/mercurial.cc
index 8b82e9daa..19ff98030 100644
--- a/src/libfetchers/mercurial.cc
+++ b/src/libfetchers/mercurial.cc
@@ -201,8 +201,17 @@ struct MercurialInputScheme : InputScheme
 
         if (!input.getRef()) input.attrs.insert_or_assign("ref", "default");
 
+        auto checkHashType = [&](const std::optional<Hash> & hash)
+        {
+            if (hash.has_value() && hash->type != htSHA1)
+                throw Error("Hash '%s' is not supported by Mercurial. Only sha1 is supported.", hash->to_string(Base16, true));
+        };
+
+
         auto getLockedAttrs = [&]()
         {
+            checkHashType(input.getRev());
+
             return Attrs({
                 {"type", "hg"},
                 {"name", name},