Crypto: Collapse initializer qll's into operations.

Author: bdrodes

cpp/ql/lib/experimental/quantum/OpenSSL/Operations/EVPCipherInitializer.qll

@@ -1,9 +1,117 @@
 private import experimental.quantum.Language
 private import experimental.quantum.OpenSSL.CtxFlow as CTXFlow
-private import EVPCipherInitializer
 private import OpenSSLOperationBase
 private import experimental.quantum.OpenSSL.AlgorithmValueConsumers.OpenSSLAlgorithmValueConsumers
 
+module EncValToInitEncArgConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source.asExpr().getValue().toInt() in [0, 1] }
+
+  predicate isSink(DataFlow::Node sink) {
+    exists(EVP_Cipher_Initializer initCall | sink.asExpr() = initCall.getOperationSubtypeArg())
+  }
+}
+
+module EncValToInitEncArgFlow = DataFlow::Global<EncValToInitEncArgConfig>;
+
+int getEncConfigValue(Expr e) {
+  exists(EVP_Cipher_Initializer initCall | e = initCall.getOperationSubtypeArg()) and
+  exists(DataFlow::Node a, DataFlow::Node b |
+    EncValToInitEncArgFlow::flow(a, b) and b.asExpr() = e and result = a.asExpr().getValue().toInt()
+  )
+}
+
+bindingset[i]
+Crypto::KeyOperationSubtype intToCipherOperationSubtype(int i) {
+  if i = 0
+  then result instanceof Crypto::TEncryptMode
+  else
+    if i = 1
+    then result instanceof Crypto::TDecryptMode
+    else result instanceof Crypto::TUnknownKeyOperationMode
+}
+
+// TODO: need to add key consumer
+abstract class EVP_Cipher_Initializer extends EVPInitialize {
+  override Expr getAlgorithmArg() { result = this.(Call).getArgument(1) }
+
+  abstract Expr getOperationSubtypeArg();
+
+  override Crypto::KeyOperationSubtype getKeyOperationSubtype() {
+    if this.(Call).getTarget().getName().toLowerCase().matches("%encrypt%")
+    then result instanceof Crypto::TEncryptMode
+    else
+      if this.(Call).getTarget().getName().toLowerCase().matches("%decrypt%")
+      then result instanceof Crypto::TDecryptMode
+      else
+        if exists(getEncConfigValue(this.getOperationSubtypeArg()))
+        then result = intToCipherOperationSubtype(getEncConfigValue(this.getOperationSubtypeArg()))
+        else result instanceof Crypto::TUnknownKeyOperationMode
+  }
+}
+
+abstract class EVP_EX_Initializer extends EVP_Cipher_Initializer {
+  override Expr getKeyArg() { result = this.(Call).getArgument(3) }
+
+  override Expr getIVArg() { result = this.(Call).getArgument(4) }
+}
+
+abstract class EVP_EX2_Initializer extends EVP_Cipher_Initializer {
+  override Expr getKeyArg() { result = this.(Call).getArgument(2) }
+
+  override Expr getIVArg() { result = this.(Call).getArgument(3) }
+}
+
+class EVP_Cipher_EX_Init_Call extends EVP_EX_Initializer {
+  EVP_Cipher_EX_Init_Call() {
+    this.(Call).getTarget().getName() in [
+        "EVP_EncryptInit_ex", "EVP_DecryptInit_ex", "EVP_CipherInit_ex"
+      ]
+  }
+
+  override Expr getOperationSubtypeArg() {
+    this.(Call).getTarget().getName().toLowerCase().matches("%cipherinit%") and
+    result = this.(Call).getArgument(5)
+  }
+}
+
+class EVP_Cipher_EX2_or_Simple_Init_Call extends EVP_EX2_Initializer {
+  EVP_Cipher_EX2_or_Simple_Init_Call() {
+    this.(Call).getTarget().getName() in [
+        "EVP_EncryptInit_ex2", "EVP_DecryptInit_ex2", "EVP_CipherInit_ex2", "EVP_EncryptInit",
+        "EVP_DecryptInit", "EVP_CipherInit"
+      ]
+  }
+
+  override Expr getOperationSubtypeArg() {
+    this.(Call).getTarget().getName().toLowerCase().matches("%cipherinit%") and
+    result = this.(Call).getArgument(4)
+  }
+}
+
+class EVP_CipherInit_SKEY_Call extends EVP_EX2_Initializer {
+  EVP_CipherInit_SKEY_Call() { this.(Call).getTarget().getName() in ["EVP_CipherInit_SKEY"] }
+
+  override Expr getOperationSubtypeArg() { result = this.(Call).getArgument(5) }
+}
+
+class EVPCipherInitializerAlgorithmArgument extends Expr {
+  EVPCipherInitializerAlgorithmArgument() {
+    exists(EVP_Cipher_Initializer initCall | this = initCall.getAlgorithmArg())
+  }
+}
+
+class EVPCipherInitializerKeyArgument extends Expr {
+  EVPCipherInitializerKeyArgument() {
+    exists(EVP_Cipher_Initializer initCall | this = initCall.getKeyArg())
+  }
+}
+
+class EVPCipherInitializerIVArgument extends Expr {
+  EVPCipherInitializerIVArgument() {
+    exists(EVP_Cipher_Initializer initCall | this = initCall.getIVArg())
+  }
+}
+
 class EVP_Cipher_Update_Call extends EVPUpdate {
   EVP_Cipher_Update_Call() {
     this.(Call).getTarget().getName() in [

cpp/ql/lib/experimental/quantum/OpenSSL/Operations/EVPCipherOperation.qll

@@ -5,9 +5,20 @@
 private import experimental.quantum.Language
 private import experimental.quantum.OpenSSL.CtxFlow as CTXFlow
 private import OpenSSLOperationBase
-private import EVPHashInitializer
 private import experimental.quantum.OpenSSL.AlgorithmValueConsumers.OpenSSLAlgorithmValueConsumers
 
+abstract class EVP_Hash_Initializer extends EVPInitialize { }
+
+class EVP_DigestInit_Variant_Calls extends EVP_Hash_Initializer {
+  EVP_DigestInit_Variant_Calls() {
+    this.(Call).getTarget().getName() in [
+        "EVP_DigestInit", "EVP_DigestInit_ex", "EVP_DigestInit_ex2"
+      ]
+  }
+
+  override Expr getAlgorithmArg() { result = this.(Call).getArgument(1) }
+}
+
 class EVP_Digest_Update_Call extends EVPUpdate {
   EVP_Digest_Update_Call() { this.(Call).getTarget().getName() = "EVP_DigestUpdate" }