Crypto: Add openssl key agreement instances and consumers (KEM and KEY_EXCH). Fix for raw algorithm names in all current instances. Update constants to include key agreement algorithms, previously missing. Note added in model for the possibility of ESDH.

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/BlockAlgorithmInstance.qll

@@ -71,7 +71,11 @@ class KnownOpenSSLBlockModeConstantAlgorithmInstance extends OpenSSLAlgorithmIns
 
   // NOTE: I'm not going to attempt to parse out the mode specific part, so returning
   // the same as the raw name for now.
-  override string getRawModeAlgorithmName() { result = this.(Literal).getValue().toString() }
+  override string getRawModeAlgorithmName() {
+    result = this.(Literal).getValue().toString()
+    or
+    result = this.(Call).getTarget().getName()
+  }
 
   override OpenSSLAlgorithmValueConsumer getAVC() { result = getterCall }
 }

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/CipherAlgorithmInstance.qll

@@ -102,7 +102,11 @@ class KnownOpenSSLCipherConstantAlgorithmInstance extends OpenSSLAlgorithmInstan
     // TODO or trace through getter ctx to set padding
   }
 
-  override string getRawAlgorithmName() { result = this.(Literal).getValue().toString() }
+  override string getRawAlgorithmName() {
+    result = this.(Literal).getValue().toString()
+    or
+    result = this.(Call).getTarget().getName()
+  }
 
   override int getKeySizeFixed() {
     this.(KnownOpenSSLCipherAlgorithmConstant).getExplicitKeySize() = result

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/EllipticCurveAlgorithmInstance.qll

@@ -32,7 +32,11 @@ class KnownOpenSSLEllipticCurveConstantAlgorithmInstance extends OpenSSLAlgorith
 
   override OpenSSLAlgorithmValueConsumer getAVC() { result = getterCall }
 
-  override string getRawEllipticCurveName() { result = this.(Literal).getValue().toString() }
+  override string getRawEllipticCurveName() {
+    result = this.(Literal).getValue().toString()
+    or
+    result = this.(Call).getTarget().getName()
+  }
 
   override Crypto::TEllipticCurveType getEllipticCurveType() {
     Crypto::ellipticCurveNameToKeySizeAndFamilyMapping(this.getParsedEllipticCurveName(), _, result)

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/HashAlgorithmInstance.qll

@@ -76,7 +76,11 @@ class KnownOpenSSLHashConstantAlgorithmInstance extends OpenSSLAlgorithmInstance
     not knownOpenSSLConstantToHashFamilyType(this, _) and result = Crypto::OtherHashType()
   }
 
-  override string getRawHashAlgorithmName() { result = this.(Literal).getValue().toString() }
+  override string getRawHashAlgorithmName() {
+    result = this.(Literal).getValue().toString()
+    or
+    result = this.(Call).getTarget().getName()
+  }
 
   override int getFixedDigestLength() {
     this.(KnownOpenSSLHashAlgorithmConstant).getExplicitDigestLength() = result

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/KeyAgreementAlgorithmInstance.qll

@@ -0,0 +1,63 @@
+import cpp
+private import experimental.quantum.Language
+private import KnownAlgorithmConstants
+private import experimental.quantum.OpenSSL.AlgorithmValueConsumers.OpenSSLAlgorithmValueConsumers
+private import experimental.quantum.OpenSSL.AlgorithmInstances.OpenSSLAlgorithmInstanceBase
+private import AlgToAVCFlow
+
+predicate knownOpenSSLConstantToKeyAgreementFamilyType(
+  KnownOpenSSLKeyAgreementAlgorithmConstant e, Crypto::TKeyAgreementType type
+) {
+  exists(string name |
+    name = e.getNormalizedName() and
+    (
+      name = "ECDH" and type = Crypto::ECDH()
+      or
+      name = "DH" and type = Crypto::DH()
+      or
+      name = "EDH" and type = Crypto::EDH()
+      or
+      name = "ESDH" and type = Crypto::EDH()
+    )
+  )
+}
+
+class KnownOpenSSLHashConstantAlgorithmInstance extends OpenSSLAlgorithmInstance,
+  Crypto::KeyAgreementAlgorithmInstance instanceof KnownOpenSSLKeyAgreementAlgorithmConstant
+{
+  OpenSSLAlgorithmValueConsumer getterCall;
+
+  KnownOpenSSLHashConstantAlgorithmInstance() {
+    // Two possibilities:
+    // 1) The source is a literal and flows to a getter, then we know we have an instance
+    // 2) The source is a KnownOpenSSLAlgorithm is call, and we know we have an instance immediately from that
+    // Possibility 1:
+    this instanceof Literal and
+    exists(DataFlow::Node src, DataFlow::Node sink |
+      // Sink is an argument to a CipherGetterCall
+      sink = getterCall.(OpenSSLAlgorithmValueConsumer).getInputNode() and
+      // Source is `this`
+      src.asExpr() = this and
+      // This traces to a getter
+      KnownOpenSSLAlgorithmToAlgorithmValueConsumerFlow::flow(src, sink)
+    )
+    or
+    // Possibility 2:
+    this instanceof DirectAlgorithmValueConsumer and getterCall = this
+  }
+
+  override OpenSSLAlgorithmValueConsumer getAVC() { result = getterCall }
+
+  override Crypto::TKeyAgreementType getKeyAgreementType() {
+    knownOpenSSLConstantToKeyAgreementFamilyType(this, result)
+    or
+    not knownOpenSSLConstantToKeyAgreementFamilyType(this, _) and
+    result = Crypto::OtherKeyAgreementType()
+  }
+
+  override string getRawKeyAgreementAlgorithmName() {
+    result = this.(Literal).getValue().toString()
+    or
+    result = this.(Call).getTarget().getName()
+  }
+}

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/KnownAlgorithmConstants.qll

@@ -67,6 +67,10 @@ class KnownOpenSSLSignatureAlgorithmConstant extends KnownOpenSSLAlgorithmConsta
   KnownOpenSSLSignatureAlgorithmConstant() { resolveAlgorithmFromExpr(this, _, "SIGNATURE") }
 }
 
+class KnownOpenSSLKeyAgreementAlgorithmConstant extends KnownOpenSSLAlgorithmConstant {
+  KnownOpenSSLKeyAgreementAlgorithmConstant() { resolveAlgorithmFromExpr(this, _, "KEY_AGREEMENT") }
+}
+
 /**
  * Resolves a call to a 'direct algorithm getter', e.g., EVP_MD5()
  * This approach to fetching algorithms was used in OpenSSL 1.0.2.
@@ -141,6 +145,14 @@ predicate customAliases(string target, string alias) {
  * The `target` and `alias` are converted to lowercase to be of a standard form.
  */
 predicate defaultAliases(string target, string alias) {
+  // "DH" and "DHX" are not aliases in the traditional sense,
+  // i.e., they are not registered as aliases explicitly,
+  // rather they appear in common usage, and experiments reveal their
+  // NID matches those of the `dhKeyAgreement` and `x9.42 dh` algorithms respectively.
+  alias = "dh" and target = "dhKeyAgreement"
+  or
+  alias = "dhx" and target = "x9.42 dh"
+  or
   alias = "aes128" and target = "aes-128-cbc"
   or
   alias = "aes192" and target = "aes-192-cbc"
@@ -236,6 +248,10 @@ predicate defaultAliases(string target, string alias) {
  * `algType` is the type of algorithm (e.g., "SYMMETRIC_ENCRYPTION")
  */
 predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized, string algType) {
+  name = "dhKeyAgreement" and nid = 28 and normalized = "DH" and algType = "KEY_AGREEMENT"
+  or
+  name = "x9.42 dh" and nid = 29 and normalized = "DH" and algType = "KEY_AGREEMENT"
+  or
   name = "rsa" and nid = 19 and normalized = "RSA" and algType = "ASYMMETRIC_ENCRYPTION"
   or
   name = "prime192v1" and nid = 409 and normalized = "PRIME192V1" and algType = "ELLIPTIC_CURVE"
@@ -868,6 +884,8 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   or
   name = "id-alg-dh-sig-hmac-sha1" and nid = 325 and normalized = "SHA1" and algType = "HASH"
   or
+  name = "id-alg-dh-sig-hmac-sha1" and nid = 325 and normalized = "DH" and algType = "KEY_AGREEMENT"
+  or
   name = "aes-128-ofb" and nid = 420 and normalized = "AES-128" and algType = "SYMMETRIC_ENCRYPTION"
   or
   name = "aes-128-ofb" and nid = 420 and normalized = "OFB" and algType = "BLOCK_MODE"
@@ -1369,9 +1387,9 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   or
   name = "kx-rsa" and nid = 1037 and normalized = "RSA" and algType = "ASYMMETRIC_ENCRYPTION"
   or
-  name = "kx-ecdhe" and nid = 1038 and normalized = "ECDH" and algType = "KEY_EXCHANGE"
+  name = "kx-ecdhe" and nid = 1038 and normalized = "ECDH" and algType = "KEY_AGREEMENT"
   or
-  name = "kx-ecdhe-psk" and nid = 1040 and normalized = "ECDH" and algType = "KEY_EXCHANGE"
+  name = "kx-ecdhe-psk" and nid = 1040 and normalized = "ECDH" and algType = "KEY_AGREEMENT"
   or
   name = "kx-rsa-psk" and nid = 1042 and normalized = "RSA" and algType = "ASYMMETRIC_ENCRYPTION"
   or
@@ -1679,11 +1697,11 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   or
   name = "x448" and nid = 1035 and normalized = "X448" and algType = "ELLIPTIC_CURVE"
   or
-  name = "x448" and nid = 1035 and normalized = "X448" and algType = "KEY_EXCHANGE"
+  name = "x448" and nid = 1035 and normalized = "X448" and algType = "KEY_AGREEMENT"
   or
   name = "x25519" and nid = 1034 and normalized = "X25519" and algType = "ELLIPTIC_CURVE"
   or
-  name = "x25519" and nid = 1034 and normalized = "X25519" and algType = "KEY_EXCHANGE"
+  name = "x25519" and nid = 1034 and normalized = "X25519" and algType = "KEY_AGREEMENT"
   or
   name = "authecdsa" and nid = 1047 and normalized = "ECDSA" and algType = "SIGNATURE"
   or
@@ -1783,51 +1801,101 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "SHA1" and
   algType = "HASH"
   or
+  name = "dhsinglepass-cofactordh-sha1kdf-scheme" and
+  nid = 941 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-cofactordh-sha224kdf-scheme" and
   nid = 942 and
   normalized = "SHA-224" and
   algType = "HASH"
   or
+  name = "dhsinglepass-cofactordh-sha224kdf-scheme" and
+  nid = 942 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-cofactordh-sha256kdf-scheme" and
   nid = 943 and
   normalized = "SHA-256" and
   algType = "HASH"
   or
+  name = "dhsinglepass-cofactordh-sha256kdf-scheme" and
+  nid = 943 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-cofactordh-sha384kdf-scheme" and
   nid = 944 and
   normalized = "SHA-384" and
   algType = "HASH"
   or
+  name = "dhsinglepass-cofactordh-sha384kdf-scheme" and
+  nid = 944 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-cofactordh-sha512kdf-scheme" and
   nid = 945 and
   normalized = "SHA-512" and
   algType = "HASH"
   or
+  name = "dhsinglepass-cofactordh-sha512kdf-scheme" and
+  nid = 945 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-stddh-sha1kdf-scheme" and
   nid = 936 and
   normalized = "SHA1" and
   algType = "HASH"
   or
+  name = "dhsinglepass-stddh-sha1kdf-scheme" and
+  nid = 936 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-stddh-sha224kdf-scheme" and
   nid = 937 and
   normalized = "SHA-224" and
   algType = "HASH"
   or
+  name = "dhsinglepass-stddh-sha224kdf-scheme" and
+  nid = 937 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-stddh-sha256kdf-scheme" and
   nid = 938 and
   normalized = "SHA-256" and
   algType = "HASH"
   or
+  name = "dhsinglepass-stddh-sha256kdf-scheme" and
+  nid = 938 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-stddh-sha384kdf-scheme" and
   nid = 939 and
   normalized = "SHA-384" and
   algType = "HASH"
   or
+  name = "dhsinglepass-stddh-sha384kdf-scheme" and
+  nid = 939 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dhsinglepass-stddh-sha512kdf-scheme" and
   nid = 940 and
   normalized = "SHA-512" and
   algType = "HASH"
   or
+  name = "dhsinglepass-stddh-sha512kdf-scheme" and
+  nid = 940 and
+  normalized = "DH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "dsa-old" and nid = 67 and normalized = "DSA" and algType = "SIGNATURE"
   or
   name = "dsa-sha" and nid = 66 and normalized = "DSA" and algType = "SIGNATURE"
@@ -1987,7 +2055,7 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "GOST" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
-  name = "gost r 34.10-2001 dh" and
+  name = "gost r 34.10-2001 dh" and // TODO: review this algorithm
   nid = 817 and
   normalized = "GOST" and
   algType = "SYMMETRIC_ENCRYPTION"
@@ -2057,7 +2125,7 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "GOST" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
-  name = "gost r 34.10-94 dh" and
+  name = "gost r 34.10-94 dh" and // TODO: review this algorithm
   nid = 818 and
   normalized = "GOST" and
   algType = "SYMMETRIC_ENCRYPTION"
@@ -2272,7 +2340,7 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "GOSTR34102001" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
-  name = "id-gostr3410-2001dh" and
+  name = "id-gostr3410-2001dh" and // TODO: review this algorithm
   nid = 817 and
   normalized = "GOSTR34102001" and
   algType = "SYMMETRIC_ENCRYPTION"
@@ -2337,7 +2405,7 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "GOSTR341094" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
-  name = "id-gostr3410-94dh" and
+  name = "id-gostr3410-94dh" and // TODO: review this algorithm
   nid = 818 and
   normalized = "GOSTR341094" and
   algType = "SYMMETRIC_ENCRYPTION"
@@ -2421,16 +2489,31 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "3DES" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
+  name = "id-smime-alg-esdhwith3des" and
+  nid = 241 and
+  normalized = "ESDH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "id-smime-alg-esdhwithrc2" and
   nid = 242 and
   normalized = "RC2" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
+  name = "id-smime-alg-esdhwithrc2" and
+  nid = 242 and
+  normalized = "ESDH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "id-smime-alg-rc2wrap" and
   nid = 244 and
   normalized = "RC2" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
+  name = "id_smime_alg_esdh" and
+  nid = 245 and
+  normalized = "ESDH" and
+  algType = "KEY_AGREEMENT"
+  or
   name = "id-tc26-gost-28147-param-z" and
   nid = 1003 and
   normalized = "GOST28147" and
@@ -2476,9 +2559,9 @@ predicate knownOpenSSLAlgorithmLiteral(string name, int nid, string normalized,
   normalized = "GOST34102012" and
   algType = "SYMMETRIC_ENCRYPTION"
   or
-  name = "kxecdhe" and nid = 1038 and normalized = "ECDH" and algType = "KEY_EXCHANGE"
+  name = "kxecdhe" and nid = 1038 and normalized = "ECDH" and algType = "KEY_AGREEMENT"
   or
-  name = "kxecdhe-psk" and nid = 1040 and normalized = "ECDH" and algType = "KEY_EXCHANGE"
+  name = "kxecdhe-psk" and nid = 1040 and normalized = "ECDH" and algType = "KEY_AGREEMENT"
   or
   name = "kxgost" and nid = 1045 and normalized = "GOST" and algType = "SYMMETRIC_ENCRYPTION"
   or

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmInstances/PaddingAlgorithmInstance.qll

@@ -90,7 +90,11 @@ class KnownOpenSSLPaddingConstantAlgorithmInstance extends OpenSSLAlgorithmInsta
     isPaddingSpecificConsumer = true
   }
 
-  override string getRawPaddingAlgorithmName() { result = this.(Literal).getValue().toString() }
+  override string getRawPaddingAlgorithmName() {
+    result = this.(Literal).getValue().toString()
+    or
+    result = this.(Call).getTarget().getName()
+  }
 
   override OpenSSLAlgorithmValueConsumer getAVC() { result = getterCall }
 

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmValueConsumers/KEMAlgorithmValueConsumer.qll

@@ -0,0 +1,28 @@
+import cpp
+private import experimental.quantum.Language
+private import semmle.code.cpp.dataflow.new.DataFlow
+private import experimental.quantum.OpenSSL.AlgorithmValueConsumers.OpenSSLAlgorithmValueConsumerBase
+private import experimental.quantum.OpenSSL.AlgorithmInstances.OpenSSLAlgorithmInstances
+
+abstract class KEMAlgorithmValueConsumer extends OpenSSLAlgorithmValueConsumer { }
+
+class EVPKEMAlgorithmValueConsumer extends KEMAlgorithmValueConsumer {
+  DataFlow::Node valueArgNode;
+  DataFlow::Node resultNode;
+
+  EVPKEMAlgorithmValueConsumer() {
+    resultNode.asExpr() = this and
+    (
+      this.(Call).getTarget().getName() = "EVP_KEM_fetch" and
+      valueArgNode.asExpr() = this.(Call).getArgument(1)
+    )
+  }
+
+  override DataFlow::Node getResultNode() { result = resultNode }
+
+  override Crypto::ConsumerInputDataFlowNode getInputNode() { result = valueArgNode }
+
+  override Crypto::AlgorithmInstance getAKnownAlgorithmSource() {
+    exists(OpenSSLAlgorithmInstance i | i.getAVC() = this and result = i)
+  }
+}

cpp/ql/lib/experimental/quantum/OpenSSL/AlgorithmValueConsumers/KeyExchangeAlgorithmValueConsumer.qll

@@ -0,0 +1,28 @@
+import cpp
+private import experimental.quantum.Language
+private import semmle.code.cpp.dataflow.new.DataFlow
+private import experimental.quantum.OpenSSL.AlgorithmValueConsumers.OpenSSLAlgorithmValueConsumerBase
+private import experimental.quantum.OpenSSL.AlgorithmInstances.OpenSSLAlgorithmInstances
+
+abstract class KeyExchangeAlgorithmValueConsumer extends OpenSSLAlgorithmValueConsumer { }
+
+class EVPKeyExchangeAlgorithmValueConsumer extends KeyExchangeAlgorithmValueConsumer {
+  DataFlow::Node valueArgNode;
+  DataFlow::Node resultNode;
+
+  EVPKeyExchangeAlgorithmValueConsumer() {
+    resultNode.asExpr() = this and
+    (
+      this.(Call).getTarget().getName() = "EVP_KEYEXCH_fetch" and
+      valueArgNode.asExpr() = this.(Call).getArgument(1)
+    )
+  }
+
+  override DataFlow::Node getResultNode() { result = resultNode }
+
+  override Crypto::ConsumerInputDataFlowNode getInputNode() { result = valueArgNode }
+
+  override Crypto::AlgorithmInstance getAKnownAlgorithmSource() {
+    exists(OpenSSLAlgorithmInstance i | i.getAVC() = this and result = i)
+  }
+}