Check for canonical public keys and signatures

Only enabled inside tests for now.

1 files changed, 87 insertions, 0 deletions

diff --git a/src/test/canonical_tests.cpp b/src/test/canonical_tests.cpp
new file mode 100644
index 0000000000..42d21f8ac5
--- /dev/null
+++ b/src/test/canonical_tests.cpp
@@ -0,0 +1,87 @@
+//
+// Unit tests for canonical signatures
+
+#include "json/json_spirit_writer_template.h"
+#include <boost/test/unit_test.hpp>
+#include <openssl/ecdsa.h>
+
+#include "key.h"
+#include "script.h"
+#include "util.h"
+
+using namespace std;
+using namespace json_spirit;
+
+
+// In script_tests.cpp
+extern Array read_json(const std::string& filename);
+
+BOOST_AUTO_TEST_SUITE(canonical_tests)
+
+// OpenSSL-based test for canonical signature (without test for hashtype byte)
+bool static IsCanonicalSignature_OpenSSL_inner(const std::vector<unsigned char>& vchSig)
+{
+    if (vchSig.size() == 0)
+        return false;
+    const unsigned char *input = &vchSig[0];
+    ECDSA_SIG *psig = NULL;
+    d2i_ECDSA_SIG(&psig, &input, vchSig.size());
+    if (psig == NULL)
+        return false;
+    unsigned char buf[256];
+    unsigned char *pbuf = buf;
+    unsigned int nLen = i2d_ECDSA_SIG(psig, NULL);
+    if (nLen != vchSig.size()) {
+        ECDSA_SIG_free(psig);
+        return false;
+    }
+    nLen = i2d_ECDSA_SIG(psig, &pbuf);
+    ECDSA_SIG_free(psig);
+    return (memcmp(&vchSig[0], &buf[0], nLen) == 0);
+}
+
+// OpenSSL-based test for canonical signature
+bool static IsCanonicalSignature_OpenSSL(const std::vector<unsigned char> &vchSignature) {
+    if (vchSignature.size() < 1)
+        return false;
+    if (vchSignature.size() > 127)
+        return false;
+    if (vchSignature[vchSignature.size() - 1] & 0x7C)
+        return false;
+
+    std::vector<unsigned char> vchSig(vchSignature);
+    vchSig.pop_back();
+    if (!IsCanonicalSignature_OpenSSL_inner(vchSig))
+        return false;
+    return true;
+}
+
+BOOST_AUTO_TEST_CASE(script_canon)
+{
+    Array tests = read_json("sig_canonical.json");
+
+    BOOST_FOREACH(Value &tv, tests) {
+        string test = tv.get_str();
+        if (IsHex(test)) {
+            std::vector<unsigned char> sig = ParseHex(test);
+            BOOST_CHECK_MESSAGE(IsCanonicalSignature(sig), test);
+            BOOST_CHECK_MESSAGE(IsCanonicalSignature_OpenSSL(sig), test);
+        }
+    }
+}
+
+BOOST_AUTO_TEST_CASE(script_noncanon)
+{
+    Array tests = read_json("sig_noncanonical.json");
+
+    BOOST_FOREACH(Value &tv, tests) {
+        string test = tv.get_str();
+        if (IsHex(test)) {
+            std::vector<unsigned char> sig = ParseHex(test);
+            BOOST_CHECK_MESSAGE(!IsCanonicalSignature(sig), test);
+            BOOST_CHECK_MESSAGE(!IsCanonicalSignature_OpenSSL(sig), test);
+        }
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()