python: fixes and additions for experimental key derivation function query library

python/ql/lib/experimental/cryptography/CryptoAlgorithmNames.qll

@@ -104,9 +104,9 @@ predicate isSymmetricEncryptionAlgorithm(string name) {
 predicate isKeyDerivationAlgorithm(string name) {
   name =
     [
-      "ARGON2", "CONCATKDF", "CONCATKDFHASH", "CONCATKDFHMAC", "KBKDFCMAC", "BCRYPT", "HKDF",
-      "HKDFEXPAND", "KBKDF", "KBKDFHMAC", "PBKDF1", "PBKDF2", "PBKDF2HMAC", "PKCS5", "SCRYPT",
-      "X963KDF", "EVPKDF"
+      "ARGON2", "ARGON2D", "ARGON2I", "ARGON2ID", "CONCATKDF", "CONCATKDFHASH", "CONCATKDFHMAC",
+      "KBKDFCMAC", "BCRYPT", "HKDF", "HKDFEXPAND", "KBKDF", "KBKDFHMAC", "PBKDF1", "PBKDF2",
+      "PBKDF2HMAC", "PKCS5", "SCRYPT", "X963KDF", "EVPKDF"
     ]
 }
 

python/ql/lib/experimental/cryptography/CryptoArtifact.qll

@@ -135,6 +135,10 @@ abstract class KeyDerivationOperation extends CryptographicOperation {
 
   DataFlow::Node getHashConfigSrc() { none() }
 
+  DataFlow::Node getLanesConfigSrc() { none() }
+
+  DataFlow::Node getMemoryCostConfigSrc() { none() }
+
   // TODO: get encryption algorithm for CBC-based KDF?
   DataFlow::Node getDerivedKeySizeSrc() { none() }
 
@@ -147,6 +151,10 @@ abstract class KeyDerivationOperation extends CryptographicOperation {
 
   abstract predicate requiresHash();
 
+  abstract predicate requiresLanes();
+
+  abstract predicate requiresMemoryCost();
+
   //abstract predicate requiresKeySize(); // Going to assume all requires a size
   abstract predicate requiresMode();
 }

python/ql/lib/experimental/cryptography/modules/CryptographyModule.qll

@@ -70,10 +70,10 @@ module KDF {
             .getMember(algName) and
       result = algModule.asSource() and
       // https://github.com/pyca/cryptography/tree/main/src/cryptography/hazmat/primitives/kdf
-      member in ["concatkdf", "hkdf", "kbkdf", "pbkdf2", "scrypt", "x963kdf"] and
+      member in ["argon2", "concatkdf", "hkdf", "kbkdf", "pbkdf2", "scrypt", "x963kdf"] and
       algName in [
-          "ConcatKDFHash", "ConcatKDFHMAC", "HKDF", "HKDFExpand", "KBKDFCMAC", "KBKDFHMAC",
-          "PBKDF2HMAC", "Scrypt", "X963KDF"
+          "Argon2d", "Argon2i", "Argon2id", "ConcatKDFHash", "ConcatKDFHMAC", "HKDF",
+          "HKDFExpand", "KBKDFCMAC", "KBKDFHMAC", "PBKDF2HMAC", "Scrypt", "X963KDF"
         ]
     )
   }
@@ -111,21 +111,31 @@ module KDF {
     }
 
     override predicate requiresSalt() {
-      this.getAlgorithm().getKDFName() in ["PBKDF2HMAC", "CONCATKDFHMAC", "HKDF"]
+      this.getAlgorithm().getKDFName() in ["PBKDF2HMAC", "CONCATKDFHMAC", "HKDF", "SCRYPT", "ARGON2"]
     }
 
-    override predicate requiresIteration() { this.getAlgorithm().getKDFName() in ["PBKDF2HMAC"] }
+    override predicate requiresIteration() { this.getAlgorithm().getKDFName() in ["PBKDF2HMAC", "ARGON2"] }
+
+    override predicate requiresLanes() { this.getAlgorithm().getKDFName() in ["ARGON2"] }
+
+    override predicate requiresMemoryCost() { this.getAlgorithm().getKDFName() in ["ARGON2"] }
 
     override DataFlow::Node getIterationSizeSrc() {
       this.requiresIteration() and
-      // ASSUMPTION: ONLY EVER in arg 3 in PBKDF2HMAC
-      result = Utils::getUltimateSrcFromApiNode(this.getParameter(3, "iterations"))
+      if this.getAlgorithm().getKDFName() = "ARGON2"
+      then result = Utils::getUltimateSrcFromApiNode(this.getKeywordParameter("iterations"))
+      else
+        // ASSUMPTION: ONLY EVER in arg 3 in PBKDF2HMAC
+        result = Utils::getUltimateSrcFromApiNode(this.getParameter(3, "iterations"))
     }
 
     override DataFlow::Node getSaltConfigSrc() {
       this.requiresSalt() and
+      // ARGON2 variants have it as a keyword-only parameter
+      if this.getAlgorithm().getKDFName() = "ARGON2"
+      then result = Utils::getUltimateSrcFromApiNode(this.getKeywordParameter("salt"))
       // SCRYPT has it in arg 1
-      if this.getAlgorithm().getKDFName() = "SCRYPT"
+      else if this.getAlgorithm().getKDFName() = "SCRYPT"
       then result = Utils::getUltimateSrcFromApiNode(this.getParameter(1, "salt"))
       else
         // EVERYTHING ELSE that uses salt is in arg 2
@@ -138,9 +148,23 @@ module KDF {
       result = Utils::getUltimateSrcFromApiNode(this.getParameter(0, "algorithm"))
     }
 
+    override DataFlow::Node getLanesConfigSrc() {
+      this.requiresLanes() and 
+      // ASSUMPTION: ONLY EVER in keyword parameter
+      result = Utils::getUltimateSrcFromApiNode(this.getKeywordParameter("lanes"))
+    }
+
+    override DataFlow::Node getMemoryCostConfigSrc() {
+      this.requiresMemoryCost() and
+      // ASSUMPTION: ONLY EVER in keyword parameter
+      result = Utils::getUltimateSrcFromApiNode(this.getKeywordParameter("memory_cost"))
+    }
+
     // TODO: get encryption algorithm for CBC-based KDF?
     override DataFlow::Node getDerivedKeySizeSrc() {
-      if this.getAlgorithm().getKDFName() in ["KBKDFHMAC", "KBKDFCMAC"]
+      if this.getAlgorithm().getKDFName() = "ARGON2"
+      then result = Utils::getUltimateSrcFromApiNode(this.getKeywordParameter("length"))
+      else if this.getAlgorithm().getKDFName() in ["KBKDFHMAC", "KBKDFCMAC"]
       then result = Utils::getUltimateSrcFromApiNode(this.getParameter(2, "length"))
       else result = Utils::getUltimateSrcFromApiNode(this.getParameter(1, "length"))
     }

python/ql/lib/experimental/cryptography/modules/stdlib/HashlibModule.qll

@@ -197,6 +197,10 @@ module KDF {
     override predicate requiresSalt() { any() }
 
     override predicate requiresIteration() { any() }
+
+    override predicate requiresLanes() { none() }
+
+    override predicate requiresMemoryCost() { none() }
   }
 
   // TODO: better modeling of scrypt
@@ -233,5 +237,9 @@ module KDF {
     override predicate requiresSalt() { any() }
 
     override predicate requiresIteration() { none() }
+
+    override predicate requiresLanes() { none() }
+
+    override predicate requiresMemoryCost() { none() }
   }
 }