* computeStorePathForText: take the references into account when

  computing the store path (NIX-77).  This is an important security
  property in multi-user Nix stores.

  Note that this changes the store paths of derivations (since the
  derivation aterms are added using addTextToStore), but not most
  outputs (unless they use builtins.toFile).

5 files changed, 18 insertions, 6 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 589faf48ae25..aca5f5856de8 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -624,7 +624,7 @@ static Expr prim_toFile(EvalState & state, const ATermVector & args)
     }
     
     Path storePath = readOnlyMode
-        ? computeStorePathForText(name, contents)
+        ? computeStorePathForText(name, contents, refs)
         : store->addTextToStore(name, contents, refs);
 
     /* Note: we don't need to add `context' to the context of the
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index aea95ef31477..3456a5f714a0 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -29,7 +29,7 @@ Path writeDerivation(const Derivation & drv, const string & name)
     string suffix = name + drvExtension;
     string contents = atPrint(unparseDerivation(drv));
     return readOnlyMode
-        ? computeStorePathForText(suffix, contents)
+        ? computeStorePathForText(suffix, contents, references)
         : store->addTextToStore(suffix, contents, references);
 }
 
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 34fe33461f20..56d97a048aad 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -667,7 +667,7 @@ Path LocalStore::addToStore(const Path & _srcPath, bool fixed,
 Path LocalStore::addTextToStore(const string & suffix, const string & s,
     const PathSet & references)
 {
-    Path dstPath = computeStorePathForText(suffix, s);
+    Path dstPath = computeStorePathForText(suffix, s, references);
     
     addTempRoot(dstPath);
 
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index be9ea788bc20..6ffbaf1ebf1e 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -73,6 +73,8 @@ Path makeStorePath(const string & type,
     string s = type + ":sha256:" + printHash(hash) + ":"
         + nixStore + ":" + suffix;
 
+    printMsg(lvlError, s);
+    
     checkStoreName(suffix);
 
     return nixStore + "/"
@@ -114,10 +116,19 @@ std::pair<Path, Hash> computeStorePathForPath(const Path & srcPath,
 }
 
 
-Path computeStorePathForText(const string & suffix, const string & s)
+Path computeStorePathForText(const string & suffix, const string & s,
+    const PathSet & references)
 {
     Hash hash = hashString(htSHA256, s);
-    return makeStorePath("text", hash, suffix);
+    /* Stuff the references (if any) into the type.  This is a bit
+       hacky, but we can't put them in `s' since that would be
+       ambiguous. */
+    string type = "text";
+    for (PathSet::const_iterator i = references.begin(); i != references.end(); ++i) {
+        type += ":";
+        type += *i;
+    }
+    return makeStorePath(type, hash, suffix);
 }
 
 
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index d92b03df0621..361e7aaa1aee 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -215,7 +215,8 @@ std::pair<Path, Hash> computeStorePathForPath(const Path & srcPath,
    simply yield a different store path, so other users wouldn't be
    affected), but it has some backwards compatibility issues (the
    hashing scheme changes), so I'm not doing that for now. */
-Path computeStorePathForText(const string & suffix, const string & s);
+Path computeStorePathForText(const string & suffix, const string & s,
+    const PathSet & references);
 
 
 /* Remove the temporary roots file for this process.  Any temporary