Make use of the AES hardware module on the ESP32

doc/Doxyfile

@@ -1536,7 +1536,7 @@ INCLUDE_FILE_PATTERNS  =
 # undefined via #undef or recursively expanded use the := operator
 # instead of the = operator.
 
-PREDEFINED             =
+PREDEFINED             = CRYPTO_DOC
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then
 # this tag can be used to specify a list of macro names that should be expanded.

libraries/Crypto/AES.h

@@ -25,6 +25,15 @@
 
 #include "BlockCipher.h"
 
+// Determine which AES implementation to export to applications.
+#if defined(ESP32)
+#define CRYPTO_AES_ESP32 1
+#else
+#define CRYPTO_AES_DEFAULT 1
+#endif
+
+#if defined(CRYPTO_AES_DEFAULT) || defined(CRYPTO_DOC)
+
 class AESTiny128;
 class AESTiny256;
 class AESSmall128;
@@ -177,4 +186,71 @@ private:
     uint8_t reverse[16];
 };
 
+#endif // CRYPTO_AES_DEFAULT
+
+#if defined(CRYPTO_AES_ESP32)
+
+// "hwcrypto/aes.h" includes "rom/aes.h" which defines global enums for
+// AES128, AES192, and AES256.  The enum definitions interfere with the
+// definition of the same-named classes below.  The #define's and #undef's
+// here work around the problem by defining the enums to different names.
+#define AES128 AES128_enum
+#define AES192 AES192_enum
+#define AES256 AES256_enum
+#include "hwcrypto/aes.h"
+#undef AES128
+#undef AES192
+#undef AES256
+
+class AESCommon : public BlockCipher
+{
+public:
+    virtual ~AESCommon();
+
+    size_t blockSize() const;
+    size_t keySize() const;
+
+    bool setKey(const uint8_t *key, size_t len);
+
+    void encryptBlock(uint8_t *output, const uint8_t *input);
+    void decryptBlock(uint8_t *output, const uint8_t *input);
+
+    void clear();
+
+protected:
+    AESCommon(uint8_t keySize);
+
+private:
+    esp_aes_context ctx;
+};
+
+class AES128 : public AESCommon
+{
+public:
+    AES128() : AESCommon(16) {}
+    virtual ~AES128();
+};
+
+class AES192 : public AESCommon
+{
+public:
+    AES192() : AESCommon(24) {}
+    virtual ~AES192();
+};
+
+class AES256 : public AESCommon
+{
+public:
+    AES256() : AESCommon(32) {}
+    virtual ~AES256();
+};
+
+// The ESP32 AES context is so small that it already qualifies as "tiny".
+typedef AES128 AESTiny128;
+typedef AES256 AESTiny256;
+typedef AES128 AESSmall128;
+typedef AES256 AESSmall256;
+
+#endif // CRYPTO_AES_ESP32
+
 #endif

libraries/Crypto/AES128.cpp

@@ -24,6 +24,8 @@
 #include "Crypto.h"
 #include <string.h>
 
+#if defined(CRYPTO_AES_DEFAULT) || defined(CRYPTO_DOC)
+
 /**
  * \class AES128 AES.h <AES.h>
  * \brief AES block cipher with 128-bit keys.
@@ -350,3 +352,5 @@ void AESSmall128::clear()
     clean(reverse);
     AESTiny128::clear();
 }
+
+#endif // CRYPTO_AES_DEFAULT

libraries/Crypto/AES192.cpp

@@ -24,6 +24,8 @@
 #include "Crypto.h"
 #include <string.h>
 
+#if defined(CRYPTO_AES_DEFAULT) || defined(CRYPTO_DOC)
+
 /**
  * \class AES192 AES.h <AES.h>
  * \brief AES block cipher with 192-bit keys.
@@ -96,3 +98,5 @@ bool AES192::setKey(const uint8_t *key, size_t len)
 
     return true;
 }
+
+#endif // CRYPTO_AES_DEFAULT

libraries/Crypto/AES256.cpp

@@ -24,6 +24,8 @@
 #include "Crypto.h"
 #include <string.h>
 
+#if defined(CRYPTO_AES_DEFAULT) || defined(CRYPTO_DOC)
+
 /**
  * \class AES256 AES.h <AES.h>
  * \brief AES block cipher with 256-bit keys.
@@ -395,3 +397,5 @@ void AESSmall256::clear()
     clean(reverse);
     AESTiny256::clear();
 }
+
+#endif // CRYPTO_AES_DEFAULT

libraries/Crypto/AESCommon.cpp

@@ -24,6 +24,8 @@
 #include "Crypto.h"
 #include "utility/ProgMemUtil.h"
 
+#if defined(CRYPTO_AES_DEFAULT) || defined(CRYPTO_DOC)
+
 /**
  * \class AESCommon AES.h <AES.h>
  * \brief Abstract base class for AES block ciphers.
@@ -357,3 +359,5 @@ void AESCommon::applySbox(uint8_t *output, const uint8_t *input)
 }
 
 /** @endcond */
+
+#endif // CRYPTO_AES_DEFAULT

libraries/Crypto/AESEsp32.cpp

@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2018 Southern Storm Software, Pty Ltd.
+ *
+ * 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.
+ */
+
+#include "AES.h"
+#include "Crypto.h"
+#include <string.h>
+
+// AES implementation for ESP32 using the hardware crypto module.
+
+#if defined(CRYPTO_AES_ESP32)
+
+AESCommon::AESCommon(uint8_t keySize)
+{
+    ctx.key_bytes = keySize;
+}
+
+AESCommon::~AESCommon()
+{
+    clean(ctx.key, sizeof(ctx.key));
+}
+
+size_t AESCommon::blockSize() const
+{
+    return 16;
+}
+
+size_t AESCommon::keySize() const
+{
+    return ctx.key_bytes;
+}
+
+bool AESCommon::setKey(const uint8_t *key, size_t len)
+{
+    if (len == ctx.key_bytes) {
+        // Do the effect of esp_aes_setkey() which is just a memcpy().
+        memcpy(ctx.key, key, len);
+        return true;
+    }
+    return false;
+}
+
+void AESCommon::encryptBlock(uint8_t *output, const uint8_t *input)
+{
+    esp_aes_encrypt(&ctx, input, output);
+}
+
+void AESCommon::decryptBlock(uint8_t *output, const uint8_t *input)
+{
+    esp_aes_decrypt(&ctx, input, output);
+}
+
+void AESCommon::clear()
+{
+    clean(ctx.key, sizeof(ctx.key));
+}
+
+AES128::~AES128()
+{
+}
+
+AES192::~AES192()
+{
+}
+
+AES256::~AES256()
+{
+}
+
+#endif // CRYPTO_AES_ESP32

libraries/Crypto/library.json

@@ -1,6 +1,6 @@
 {
     "name": "Crypto",
-    "version": "0.1.4",
+    "version": "0.1.5",
     "keywords": "AES128,AES192,AES256,Speck,CTR,CFB,CBC,OFB,EAX,GCM,XTS,ChaCha,ChaChaPoly,EAX,GCM,SHA256,SHA512,SHA3_256,SHA3_512,BLAKE2s,BLAKE2b,SHAKE128,SHAKE256,Poly1305,GHASH,OMAC,Curve25519,Ed25519,P521,RNG,NOISE",
     "description": "Arduino CryptoLibs - All cryptographic algorithms have been optimized for 8-bit Arduino platforms like the Uno",
     "authors":