QA: add test for HKDF HMAC_SHA256 L32

Author: jonasschnelli

src/test/crypto_tests.cpp

@@ -5,12 +5,13 @@
 #include <crypto/aes.h>
 #include <crypto/chacha20.h>
 #include <crypto/poly1305.h>
+#include <crypto/hkdf_sha256_32.h>
+#include <crypto/hmac_sha256.h>
+#include <crypto/hmac_sha512.h>
 #include <crypto/ripemd160.h>
 #include <crypto/sha1.h>
 #include <crypto/sha256.h>
 #include <crypto/sha512.h>
-#include <crypto/hmac_sha256.h>
-#include <crypto/hmac_sha512.h>
 #include <random.h>
 #include <util/strencodings.h>
 #include <test/test_bitcoin.h>
@@ -212,6 +213,22 @@ static void TestPoly1305(const std::string &hexmessage, const std::string &hexke
     BOOST_CHECK(tag == tagres);
 }
 
+static void TestHKDF_SHA256_32(const std::string &ikm_hex, const std::string &salt_hex, const std::string &info_hex, const std::string &okm_check_hex) {
+    std::vector<unsigned char> initial_key_material = ParseHex(ikm_hex);
+    std::vector<unsigned char> salt = ParseHex(salt_hex);
+    std::vector<unsigned char> info = ParseHex(info_hex);
+
+
+    // our implementation only supports strings for the "info" and "salt", stringify them
+    std::string salt_stringified(reinterpret_cast<char*>(salt.data()), salt.size());
+    std::string info_stringified(reinterpret_cast<char*>(info.data()), info.size());
+
+    CHKDF_HMAC_SHA256_L32 hkdf32(initial_key_material.data(), initial_key_material.size(), salt_stringified);
+    unsigned char out[32];
+    hkdf32.Expand32(info_stringified, out);
+    BOOST_CHECK(HexStr(out, out + 32) == okm_check_hex);
+}
+
 static std::string LongTestString() {
     std::string ret;
     for (int i=0; i<200000; i++) {
@@ -606,6 +623,26 @@ BOOST_AUTO_TEST_CASE(poly1305_testvector)
                  "13000000000000000000000000000000");
 }
 
+BOOST_AUTO_TEST_CASE(hkdf_hmac_sha256_l32_tests)
+{
+    // Use rfc5869 test vectors but trucated to 32 bytes (our implementation only support length 32)
+    TestHKDF_SHA256_32(
+                /* IKM */ "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
+                /* salt */ "000102030405060708090a0b0c",
+                /* info */ "f0f1f2f3f4f5f6f7f8f9",
+                /* expected OKM */ "3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf");
+    TestHKDF_SHA256_32(
+                "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f",
+                "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf",
+                "b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff",
+                "b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c");
+    TestHKDF_SHA256_32(
+                "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
+                "",
+                "",
+                "8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d");
+}
+
 BOOST_AUTO_TEST_CASE(countbits_tests)
 {
     FastRandomContext ctx;