diff --git a/build/crypto.m4 b/build/crypto.m4
index eae93b3c5d6..818e292def6 100644
--- a/build/crypto.m4
+++ b/build/crypto.m4
@@ -190,6 +190,37 @@ AC_DEFUN([TS_CHECK_CRYPTO_DH_GET_2048_256], [
   AC_SUBST(use_dh_get_2048_256)
 ])
 
+AC_DEFUN([TS_CHECK_CRYPTO_HKDF], [
+  enable_hkdf=no
+  _hkdf_saved_LIBS=$LIBS
+  TS_ADDTO(LIBS, [$OPENSSL_LIBS])
+  AC_MSG_CHECKING([for EVP_PKEY_CTX_hkdf_mode])
+  AC_LINK_IFELSE(
+  [
+    AC_LANG_PROGRAM([[
+#include <openssl/kdf.h>
+    ]],
+    [[
+#ifndef EVP_PKEY_CTX_hkdf_mode
+# error no EVP_PKEY_CTX_hkdf_mode support
+#endif
+    ]])
+  ],
+  [
+    AC_MSG_RESULT([yes])
+    enable_hkdf=yes
+  ],
+  [
+    AC_MSG_RESULT([no])
+  ])
+  AC_CHECK_FUNC(HKDF_extract, [
+    enable_hkdf=yes
+  ], [])
+  LIBS=$_hkdf_saved_LIBS
+  TS_ARG_ENABLE_VAR([use], [hkdf])
+  AC_SUBST(use_hkdf)
+])
+
 dnl
 dnl Since OpenSSL 1.1.0
 dnl
diff --git a/configure.ac b/configure.ac
index 9328124e753..9848a1b90cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1191,6 +1191,10 @@ TS_CHECK_CRYPTO_SET_RBIO
 # Check for DH_get_2048_256
 TS_CHECK_CRYPTO_DH_GET_2048_256
 
+# Check for HKDF support
+TS_CHECK_CRYPTO_HKDF
+AM_CONDITIONAL([HAS_HKDF], [test "x$enable_hkdf" = "xyes"])
+
 # Check for OCSP
 TS_CHECK_CRYPTO_OCSP
 
@@ -1231,6 +1235,18 @@ AC_CHECK_FUNC([EVP_MD_CTX_reset], [],
 AC_CHECK_FUNC([EVP_MD_CTX_free], [],
               [AC_DEFINE([EVP_MD_CTX_free], [EVP_MD_CTX_destroy], [Renamed in OpenSSL 1.1])])
 
+AC_MSG_CHECKING([for OpenSSL is BoringSSL])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <openssl/base.h>]],
+                                   [[
+                                     #ifndef OPENSSL_IS_BORINGSSL
+                                     # error not boringssl
+                                     #endif
+                                   ]])
+                  ],
+                  [AC_MSG_RESULT([yes]); openssl_is_boringssl=1],
+                  [AC_MSG_RESULT([no])])
+AM_CONDITIONAL([OPENSSL_IS_BORINGSSL], [test -n "$openssl_is_boringssl"])
+
 LIBS="$saved_LIBS"
 
 # 
diff --git a/include/tscore/HKDF.h b/include/tscore/HKDF.h
new file mode 100644
index 00000000000..78ad0f2e753
--- /dev/null
+++ b/include/tscore/HKDF.h
@@ -0,0 +1,45 @@
+/** @file
+
+  HKDF utility
+
+  @section license License
+
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+ */
+
+#pragma once
+
+#ifdef OPENSSL_IS_BORINGSSL
+#include <openssl/digest.h>
+#include <openssl/cipher.h>
+#else
+#include <openssl/evp.h>
+#endif
+
+class HKDF
+{
+public:
+  HKDF(const EVP_MD *digest);
+  ~HKDF();
+  int extract(uint8_t *dst, size_t *dst_len, const uint8_t *salt, size_t salt_len, const uint8_t *ikm, size_t ikm_len);
+  int expand(uint8_t *dst, size_t *dst_len, const uint8_t *prk, size_t prk_len, const uint8_t *info, size_t info_len,
+             uint16_t length);
+
+protected:
+  const EVP_MD *_digest = nullptr;
+  EVP_PKEY_CTX *_pctx   = nullptr;
+};
diff --git a/src/tscore/HKDF_boringssl.cc b/src/tscore/HKDF_boringssl.cc
new file mode 100644
index 00000000000..9fa84cdbdde
--- /dev/null
+++ b/src/tscore/HKDF_boringssl.cc
@@ -0,0 +1,41 @@
+/** @file
+ *
+ *  HKDF utility (BoringSSL version)
+ *
+ *  @section license License
+ *
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+#include "tscore/HKDF.h"
+#include <openssl/hkdf.h>
+
+HKDF::HKDF(const EVP_MD *digest) : _digest(digest) {}
+HKDF::~HKDF() {}
+
+int
+HKDF::extract(uint8_t *dst, size_t *dst_len, const uint8_t *salt, size_t salt_len, const uint8_t *ikm, size_t ikm_len)
+{
+  return HKDF_extract(dst, dst_len, this->_digest, ikm, ikm_len, salt, salt_len);
+}
+
+int
+HKDF::expand(uint8_t *dst, size_t *dst_len, const uint8_t *prk, size_t prk_len, const uint8_t *info, size_t info_len,
+             uint16_t length)
+{
+  *dst_len = length;
+  return HKDF_expand(dst, length, this->_digest, prk, prk_len, info, info_len);
+}
diff --git a/src/tscore/HKDF_openssl.cc b/src/tscore/HKDF_openssl.cc
new file mode 100644
index 00000000000..ac8d69051e1
--- /dev/null
+++ b/src/tscore/HKDF_openssl.cc
@@ -0,0 +1,102 @@
+/** @file
+ *
+ *  HKDF utility (OpenSSL version)
+ *
+ *  @section license License
+ *
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+#include "tscore/HKDF.h"
+#include <openssl/kdf.h>
+
+HKDF::HKDF(const EVP_MD *digest) : _digest(digest)
+{
+  // XXX We cannot reuse pctx now due to a bug in OpenSSL
+  // this->_pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, nullptr);
+}
+
+HKDF::~HKDF()
+{
+  EVP_PKEY_CTX_free(this->_pctx);
+  this->_pctx = nullptr;
+}
+
+int
+HKDF::extract(uint8_t *dst, size_t *dst_len, const uint8_t *salt, size_t salt_len, const uint8_t *ikm, size_t ikm_len)
+{
+  // XXX See comments in the constructor
+  if (this->_pctx) {
+    EVP_PKEY_CTX_free(this->_pctx);
+    this->_pctx = nullptr;
+  }
+  this->_pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, nullptr);
+
+  if (EVP_PKEY_derive_init(this->_pctx) != 1) {
+    return -1;
+  }
+  if (EVP_PKEY_CTX_hkdf_mode(this->_pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) != 1) {
+    return -2;
+  }
+  if (EVP_PKEY_CTX_set_hkdf_md(this->_pctx, this->_digest) != 1) {
+    return -3;
+  }
+  if (EVP_PKEY_CTX_set1_hkdf_salt(this->_pctx, salt, salt_len) != 1) {
+    return -4;
+  }
+  if (EVP_PKEY_CTX_set1_hkdf_key(this->_pctx, ikm, ikm_len) != 1) {
+    return -5;
+  }
+  if (EVP_PKEY_derive(this->_pctx, dst, dst_len) != 1) {
+    return -6;
+  }
+
+  return 1;
+}
+
+int
+HKDF::expand(uint8_t *dst, size_t *dst_len, const uint8_t *prk, size_t prk_len, const uint8_t *info, size_t info_len,
+             uint16_t length)
+{
+  // XXX See comments in the constructor
+  if (this->_pctx) {
+    EVP_PKEY_CTX_free(this->_pctx);
+    this->_pctx = nullptr;
+  }
+  this->_pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, nullptr);
+
+  if (EVP_PKEY_derive_init(this->_pctx) != 1) {
+    return -1;
+  }
+  if (EVP_PKEY_CTX_hkdf_mode(this->_pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) != 1) {
+    return -2;
+  }
+  if (EVP_PKEY_CTX_set_hkdf_md(this->_pctx, this->_digest) != 1) {
+    return -3;
+  }
+  if (EVP_PKEY_CTX_set1_hkdf_key(this->_pctx, prk, prk_len) != 1) {
+    return -5;
+  }
+  if (EVP_PKEY_CTX_add1_hkdf_info(this->_pctx, info, info_len) != 1) {
+    return -6;
+  }
+  *dst_len = length;
+  if (EVP_PKEY_derive(this->_pctx, dst, dst_len) != 1) {
+    return -7;
+  }
+
+  return 1;
+}
diff --git a/src/tscore/Makefile.am b/src/tscore/Makefile.am
index bb6fd0c1cec..336b8382afc 100644
--- a/src/tscore/Makefile.am
+++ b/src/tscore/Makefile.am
@@ -117,6 +117,17 @@ libtscore_la_SOURCES = \
 	Version.cc \
 	X509HostnameValidator.cc
 
+if HAS_HKDF
+if OPENSSL_IS_BORINGSSL
+HKDF_impl = HKDF_boringssl.cc
+else
+HKDF_impl = HKDF_openssl.cc
+endif
+libtscore_la_SOURCES += \
+  HKDF.h \
+  $(HKDF_impl)
+endif
+
 BufferWriterFormat.o : AM_CPPFLAGS += -Wno-char-subscripts
 
 #test_UNUSED_SOURCES = \
@@ -150,7 +161,7 @@ test_tscore_CPPFLAGS = $(AM_CPPFLAGS)\
 	-I$(abs_top_srcdir)/tests/include
 
 test_tscore_CXXFLAGS = -Wno-array-bounds $(AM_CXXFLAGS)
-test_tscore_LDADD = libtscore.la $(top_builddir)/src/tscpp/util/libtscpputil.la $(top_builddir)/iocore/eventsystem/libinkevent.a
+test_tscore_LDADD = libtscore.la $(top_builddir)/src/tscpp/util/libtscpputil.la $(top_builddir)/iocore/eventsystem/libinkevent.a @OPENSSL_LIBS@
 test_tscore_SOURCES = \
 	unit_tests/unit_test_main.cc \
 	unit_tests/test_AcidPtr.cc \
@@ -175,6 +186,11 @@ test_tscore_SOURCES = \
 	unit_tests/test_scoped_resource.cc \
 	unit_tests/test_ts_file.cc
 
+if HAS_HKDF
+test_tscore_SOURCES += \
+	unit_tests/test_HKDF.cc
+endif
+
 CompileParseRules_SOURCES = CompileParseRules.cc
 
 clean-local:
diff --git a/src/tscore/unit_tests/test_HKDF.cc b/src/tscore/unit_tests/test_HKDF.cc
new file mode 100644
index 00000000000..59d2a3540c3
--- /dev/null
+++ b/src/tscore/unit_tests/test_HKDF.cc
@@ -0,0 +1,311 @@
+/** @file
+
+  Tests for HKDF
+
+  @section license License
+
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+ */
+
+#include "catch.hpp"
+#include <cstring>
+#include "tscore/HKDF.h"
+
+TEST_CASE("HKDF tests", "[hkdf]")
+{
+  SECTION("Basic test case with SHA-256")
+  {
+    uint8_t ikm[] = {
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+    };
+    uint8_t salt[] = {
+      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
+    };
+    uint8_t info[] = {
+      0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9,
+    };
+    uint16_t length        = 42;
+    uint8_t expected_prk[] = {
+      0x07, 0x77, 0x09, 0x36, 0x2c, 0x2e, 0x32, 0xdf, 0x0d, 0xdc, 0x3f, 0x0d, 0xc4, 0x7b, 0xba, 0x63,
+      0x90, 0xb6, 0xc7, 0x3b, 0xb5, 0x0f, 0x9c, 0x31, 0x22, 0xec, 0x84, 0x4a, 0xd7, 0xc2, 0xb3, 0xe5,
+    };
+    uint8_t expected_okm[] = {
+      0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a, 0x90, 0x43, 0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a, 0x2d, 0x2d, 0x0a, 0x90, 0xcf,
+      0x1a, 0x5a, 0x4c, 0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4, 0xc5, 0xbf, 0x34, 0x00, 0x72, 0x08, 0xd5, 0xb8, 0x87, 0x18, 0x58, 0x65,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha256());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+
+  SECTION("Test with SHA-256 and longer inputs/outputs")
+  {
+    uint8_t ikm[] = {
+      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
+      0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+      0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
+      0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+    };
+    uint8_t salt[] = {
+      0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73,
+      0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+      0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b,
+      0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+    };
+    uint8_t info[] = {
+      0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3,
+      0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+      0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb,
+      0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
+    };
+    uint16_t length        = 82;
+    uint8_t expected_prk[] = {
+      0x06, 0xa6, 0xb8, 0x8c, 0x58, 0x53, 0x36, 0x1a, 0x06, 0x10, 0x4c, 0x9c, 0xeb, 0x35, 0xb4, 0x5c,
+      0xef, 0x76, 0x00, 0x14, 0x90, 0x46, 0x71, 0x01, 0x4a, 0x19, 0x3f, 0x40, 0xc1, 0x5f, 0xc2, 0x44,
+    };
+    uint8_t expected_okm[] = {
+      0xb1, 0x1e, 0x39, 0x8d, 0xc8, 0x03, 0x27, 0xa1, 0xc8, 0xe7, 0xf7, 0x8c, 0x59, 0x6a, 0x49, 0x34, 0x4f, 0x01, 0x2e, 0xda, 0x2d,
+      0x4e, 0xfa, 0xd8, 0xa0, 0x50, 0xcc, 0x4c, 0x19, 0xaf, 0xa9, 0x7c, 0x59, 0x04, 0x5a, 0x99, 0xca, 0xc7, 0x82, 0x72, 0x71, 0xcb,
+      0x41, 0xc6, 0x5e, 0x59, 0x0e, 0x09, 0xda, 0x32, 0x75, 0x60, 0x0c, 0x2f, 0x09, 0xb8, 0x36, 0x77, 0x93, 0xa9, 0xac, 0xa3, 0xdb,
+      0x71, 0xcc, 0x30, 0xc5, 0x81, 0x79, 0xec, 0x3e, 0x87, 0xc1, 0x4c, 0x01, 0xd5, 0xc1, 0xf3, 0x43, 0x4f, 0x1d, 0x87,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha256());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+
+  SECTION("Test with SHA-256 and zero-length salt/info")
+  {
+    uint8_t ikm[] = {
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+    };
+    uint8_t salt[]         = {};
+    uint8_t info[]         = {};
+    uint16_t length        = 42;
+    uint8_t expected_prk[] = {
+      0x19, 0xef, 0x24, 0xa3, 0x2c, 0x71, 0x7b, 0x16, 0x7f, 0x33, 0xa9, 0x1d, 0x6f, 0x64, 0x8b, 0xdf,
+      0x96, 0x59, 0x67, 0x76, 0xaf, 0xdb, 0x63, 0x77, 0xac, 0x43, 0x4c, 0x1c, 0x29, 0x3c, 0xcb, 0x04,
+    };
+    uint8_t expected_okm[] = {
+      0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f, 0x71, 0x5f, 0x80, 0x2a, 0x06, 0x3c, 0x5a, 0x31, 0xb8, 0xa1, 0x1f, 0x5c, 0x5e,
+      0xe1, 0x87, 0x9e, 0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73, 0x8d, 0x2d, 0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a, 0x96, 0xc8,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha256());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+
+  SECTION("Basic test case with SHA-1")
+  {
+    uint8_t ikm[] = {
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+    };
+    uint8_t salt[] = {
+      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
+    };
+    uint8_t info[] = {
+      0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9,
+    };
+    uint16_t length        = 42;
+    uint8_t expected_prk[] = {
+      0x9b, 0x6c, 0x18, 0xc4, 0x32, 0xa7, 0xbf, 0x8f, 0x0e, 0x71, 0xc8, 0xeb, 0x88, 0xf4, 0xb3, 0x0b, 0xaa, 0x2b, 0xa2, 0x43,
+    };
+    uint8_t expected_okm[] = {
+      0x08, 0x5a, 0x01, 0xea, 0x1b, 0x10, 0xf3, 0x69, 0x33, 0x06, 0x8b, 0x56, 0xef, 0xa5, 0xad, 0x81, 0xa4, 0xf1, 0x4b, 0x82, 0x2f,
+      0x5b, 0x09, 0x15, 0x68, 0xa9, 0xcd, 0xd4, 0xf1, 0x55, 0xfd, 0xa2, 0xc2, 0x2e, 0x42, 0x24, 0x78, 0xd3, 0x05, 0xf3, 0xf8, 0x96,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha1());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+
+  SECTION("Test with SHA-1 and longer inputs/outputs")
+  {
+    uint8_t ikm[] = {
+      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
+      0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+      0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
+      0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+    };
+    uint8_t salt[] = {
+      0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73,
+      0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+      0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b,
+      0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+    };
+    uint8_t info[] = {
+      0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3,
+      0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+      0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb,
+      0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
+    };
+    uint16_t length        = 82;
+    uint8_t expected_prk[] = {0x8a, 0xda, 0xe0, 0x9a, 0x2a, 0x30, 0x70, 0x59, 0x47, 0x8d,
+                              0x30, 0x9b, 0x26, 0xc4, 0x11, 0x5a, 0x22, 0x4c, 0xfa, 0xf6};
+    uint8_t expected_okm[] = {
+      0x0b, 0xd7, 0x70, 0xa7, 0x4d, 0x11, 0x60, 0xf7, 0xc9, 0xf1, 0x2c, 0xd5, 0x91, 0x2a, 0x06, 0xeb, 0xff, 0x6a, 0xdc, 0xae, 0x89,
+      0x9d, 0x92, 0x19, 0x1f, 0xe4, 0x30, 0x56, 0x73, 0xba, 0x2f, 0xfe, 0x8f, 0xa3, 0xf1, 0xa4, 0xe5, 0xad, 0x79, 0xf3, 0xf3, 0x34,
+      0xb3, 0xb2, 0x02, 0xb2, 0x17, 0x3c, 0x48, 0x6e, 0xa3, 0x7c, 0xe3, 0xd3, 0x97, 0xed, 0x03, 0x4c, 0x7f, 0x9d, 0xfe, 0xb1, 0x5c,
+      0x5e, 0x92, 0x73, 0x36, 0xd0, 0x44, 0x1f, 0x4c, 0x43, 0x00, 0xe2, 0xcf, 0xf0, 0xd0, 0x90, 0x0b, 0x52, 0xd3, 0xb4,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha1());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+
+  SECTION("Test with SHA-1 and zero-length salt/info")
+  {
+    uint8_t ikm[] = {
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+      0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+    };
+    uint8_t salt[]         = {};
+    uint8_t info[]         = {};
+    uint16_t length        = 42;
+    uint8_t expected_prk[] = {
+      0xda, 0x8c, 0x8a, 0x73, 0xc7, 0xfa, 0x77, 0x28, 0x8e, 0xc6, 0xf5, 0xe7, 0xc2, 0x97, 0x78, 0x6a, 0xa0, 0xd3, 0x2d, 0x01,
+    };
+    uint8_t expected_okm[] = {
+      0x0a, 0xc1, 0xaf, 0x70, 0x02, 0xb3, 0xd7, 0x61, 0xd1, 0xe5, 0x52, 0x98, 0xda, 0x9d, 0x05, 0x06, 0xb9, 0xae, 0x52, 0x05, 0x72,
+      0x20, 0xa3, 0x06, 0xe0, 0x7b, 0x6b, 0x87, 0xe8, 0xdf, 0x21, 0xd0, 0xea, 0x00, 0x03, 0x3d, 0xe0, 0x39, 0x84, 0xd3, 0x49, 0x18,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha1());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+
+  SECTION("Test with SHA-1, salt not provided (defaults to HashLen zero octets)")
+  {
+    uint8_t ikm[] = {
+      0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+      0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+    };
+    uint8_t salt[]         = {};
+    uint8_t info[]         = {};
+    uint16_t length        = 42;
+    uint8_t expected_prk[] = {
+      0x2a, 0xdc, 0xca, 0xda, 0x18, 0x77, 0x9e, 0x7c, 0x20, 0x77, 0xad, 0x2e, 0xb1, 0x9d, 0x3f, 0x3e, 0x73, 0x13, 0x85, 0xdd,
+    };
+    uint8_t expected_okm[] = {
+      0x2c, 0x91, 0x11, 0x72, 0x04, 0xd7, 0x45, 0xf3, 0x50, 0x0d, 0x63, 0x6a, 0x62, 0xf6, 0x4f, 0x0a, 0xb3, 0xba, 0xe5, 0x48, 0xaa,
+      0x53, 0xd4, 0x23, 0xb0, 0xd1, 0xf2, 0x7e, 0xbb, 0xa6, 0xf5, 0xe5, 0x67, 0x3a, 0x08, 0x1d, 0x70, 0xcc, 0xe7, 0xac, 0xfc, 0x48,
+    };
+
+    uint8_t prk[256] = {0};
+    size_t prk_len   = sizeof(prk);
+    uint8_t okm[256] = {0};
+    size_t okm_len   = sizeof(okm);
+
+    HKDF hkdf(EVP_sha1());
+
+    // Extract
+    CHECK(hkdf.extract(prk, &prk_len, salt, sizeof(salt), ikm, sizeof(ikm)) == 1);
+    CHECK(prk_len == sizeof(expected_prk));
+    CHECK(memcmp(prk, expected_prk, sizeof(expected_prk)) == 0);
+
+    // Expand
+    CHECK(hkdf.expand(okm, &okm_len, prk, prk_len, info, sizeof(info), length) == 1);
+    CHECK(okm_len == sizeof(expected_okm));
+    CHECK(memcmp(okm, expected_okm, sizeof(expected_okm)) == 0);
+  }
+}