Added HKDF support for Hash subclasses.

libraries/Crypto/HKDF.h

@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2016 Miguel Azevedo, <lobaoazevedo@ua.pt>.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef CRYPTO_HKDF_h
+#define CRYPTO_HKDF_h
+
+#include "Hash.h"
+
+/**
+ * \class HKDF HKDF.h <HKDF.h>
+ * \brief HKDF support for the hashing algorithms.
+ *
+ * Reference: RFC5869 - https://tools.ietf.org/html/rfc5869
+ *
+ * \sa Hash, SHA256
+ */
+
+template < typename T >
+class HKDF
+{
+public:
+    ~HKDF() { delete & hash; }
+
+    /**
+     * \brief First phase of HKDF.
+     * \brief Extracts a pseudorandom key from a given key and salt.
+     *  \param salt Optional (might be NULL) salt value (a non-secret random value);
+     * 	\param saltLen The salt length in bytes. If salt is NUll this value is ignored.
+     *  \param inputKey Input keying material.
+     *	\param keyLen inputKey length in bytes.
+     *	\param outputKey a previous allocated buffer of the same length of the
+     *   hash function being used.
+     *
+     * Reference: RFC5869 - https://tools.ietf.org/html/rfc5869
+     *
+     * \sa expand()
+     */
+    void extract(void *salt, size_t saltLen, void *inputKey, size_t keyLen, void *outputKey)
+    {
+	uint8_t s[hash.hashSize()];
+	if (salt == NULL) {
+	    memset(s, 0, hash.hashSize());
+	    salt = s;
+	    saltLen = hash.hashSize();
+	}
+
+	hash.resetHMAC(salt, saltLen);
+	hash.update(inputKey, keyLen);
+	hash.finalizeHMAC(salt, saltLen, outputKey, hash.hashSize());
+    }
+
+    /**
+     * \brief Second phase of HKDF.
+     * 	\brief Expands a given pseudorandom key using a given info.
+     *  \param inputKey The pseudorandom key extracted with extract().
+     *	\param info The optional (can be NULL) context and application specific information.
+     *	\param infoLen The length of info. If info is NULL this value is ignored.
+     *	\param outputKey Output keying material. A buffer of L lenght bytes.
+     *	\param L The length of outputKey in bytes.
+     *
+     * \sa extract()
+     */
+    void expand(void *inputKey, void *info, size_t infoLen,void *outputKey, size_t L)
+    {
+	int N = L / hash.hashSize();
+	uint8_t i;
+
+	infoLen = (info == NULL) ? 0 : infoLen;
+	size_t saltLen = hash.hashSize() + infoLen + 1;
+	uint8_t salt[saltLen];
+	salt[saltLen - 1] = 1;
+
+	if (info != NULL) {
+	    memcpy(salt + hash.hashSize(), info, infoLen);
+	}
+	// Calculate T(1)
+	hash.resetHMAC(inputKey, hash.hashSize());
+	hash.update(salt + hash.hashSize(), infoLen + 1);
+	hash.finalizeHMAC(inputKey, hash.hashSize(), outputKey, hash.hashSize());
+
+	salt[saltLen - 1] += 1;
+	memcpy(salt, outputKey, hash.hashSize());
+
+	// Calculate T(2) ... T(N)
+	for (i = 1; i < N; i++) {
+	    hash.resetHMAC(inputKey, hash.hashSize());
+	    hash.update(salt, saltLen);
+	    hash.finalizeHMAC(inputKey,
+			      hash.hashSize(),
+			      ((uint8_t *) outputKey) + (i * hash.hashSize()),
+			      hash.hashSize());
+
+	    salt[saltLen - 1] += 1;
+	    memcpy(salt,
+		   ((uint8_t *) outputKey) + (i * hash.hashSize()),
+		   hash.hashSize());
+	}
+
+	// Process remaining octets if there are any.
+	if (L % hash.hashSize()) {
+	    uint8_t rslt[hash.hashSize()];
+	    int remain = L - N * hash.hashSize();
+	    hash.resetHMAC(inputKey, hash.hashSize());
+	    hash.update(salt, saltLen);
+	    hash.finalizeHMAC(inputKey,
+			      hash.hashSize(),
+			      rslt,
+			      hash.hashSize());
+
+	    memcpy(((uint8_t *) outputKey) + (N * hash.hashSize()),
+		   rslt,
+		   remain);
+	}
+    }
+
+
+  private:
+      T hash;
+};
+
+#endif

libraries/Crypto/examples/TestHKDF/TestHKDF.ino

@@ -0,0 +1,209 @@
+/**
+ * This example runs tests on the HKDF implementation to verify correct
+ * behaviour using SHA256 hashing function.
+ * These test vectors are based on the ones supplied by RFC5869.
+ * Author: Miguel Azevedo <lobaoazevedo@ua.pt>
+ */
+
+#include <Crypto.h>
+#include <SHA256.h>
+#include <HKDF.h>
+#include <string.h>
+
+#define HASH_SIZE 32
+
+struct TestHashVectorHKDF {
+    const char *name;
+    uint8_t *IKM;
+    size_t IKM_size;
+    uint8_t *salt;
+    size_t salt_size;
+    uint8_t *info;
+    size_t info_size;
+    uint8_t L;
+
+    uint8_t PRK[HASH_SIZE];
+    uint8_t *OKM;
+};
+
+uint8_t ikm1[22] = { 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+		     0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+		     0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b
+};
+
+uint8_t salt1[13] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+		      0x08, 0x09, 0x0a, 0x0b, 0x0c
+};
+
+uint8_t info1[10] = { 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+		      0xf8, 0xf9
+};
+
+uint8_t okm1[42] = { 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
+};
+
+static TestHashVectorHKDF const testVectorHKDF_SHA256_1 = {
+    "HKDF-SHA-256 #1",
+    ikm1,
+    22,
+    salt1,
+    13,
+    info1,
+    10,
+    42,
+    {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},
+    okm1
+};
+
+uint8_t ikm2[80] = { 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 salt2[80] = { 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 info2[80] = { 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
+};
+
+uint8_t okm2[82] = { 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
+};
+
+static TestHashVectorHKDF const testVectorHKDF_SHA256_2 = {
+    "HKDF-SHA-256 #2",
+    ikm2,
+    80,
+    salt2,
+    80,
+    info2,
+    80,
+    82,
+    {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},
+    okm2
+};
+
+uint8_t ikm3[22] = { 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+		     0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+		     0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b
+};
+
+uint8_t okm3[42] = { 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
+};
+
+static TestHashVectorHKDF const testVectorHKDF_SHA256_3 = {
+    "HKDF-SHA-256 #3",
+    ikm1,
+    22,
+    NULL,
+    0,
+    NULL,
+    0,
+    42,
+    {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},
+    okm3
+};
+
+HKDF < SHA256 > hkdfsha256;
+
+void testHKDF(HKDF < SHA256 > *hash, const struct TestHashVectorHKDF *test)
+{
+    uint8_t prk[HASH_SIZE];
+    uint8_t okm[test->L];
+    Serial.print(test->name);
+    Serial.print(" ... ");
+
+    hash->extract(test->salt,
+		  test->salt_size,
+		  test->IKM,
+		  test->IKM_size,
+		  prk);
+
+    if (!memcmp(prk, test->PRK, HASH_SIZE))
+	Serial.print("Extract: Passed");
+    else
+	Serial.print("Extract Failed");
+
+
+    Serial.print(" ... ");
+    hash->expand(prk, test->info, test->info_size, okm, test->L);
+
+    if (!memcmp(okm, test->OKM, test->L))
+	Serial.println("Expand: Passed");
+    else
+	Serial.println("Expand: Failed");
+
+}
+
+void setup()
+{
+    Serial.begin(9600);
+
+    Serial.println();
+
+    Serial.print("State Size ...");
+    Serial.println(sizeof(SHA256));
+    Serial.println();
+
+    Serial.println("Test Vectors:");
+    testHKDF(&hkdfsha256, &testVectorHKDF_SHA256_1);
+    testHKDF(&hkdfsha256, &testVectorHKDF_SHA256_2);
+    testHKDF(&hkdfsha256, &testVectorHKDF_SHA256_3);
+}
+
+void loop()
+{
+}