Decoupling business layer from hardware layer in Signer component

- Added HAL headers
- Added HAL implementation for Ledger
- Refactored necessary common sources
- Refactored necessary Signer sources
- Updated Signer Makefile to include HAL code
- Removed HSM_SIMULATOR define in favor of HSM_PLATFORM_* defines
- Included X86 (partial) implemenations of some HAL modules (exceptions, logging, hashing)

ledger/src/common/src/apdu.h

@@ -29,6 +29,8 @@
 #ifndef __APDU_H
 #define __APDU_H
 
+#include "common_requirements.h"
+
 // CLA for the entire protocol
 #define CLA 0x80
 
@@ -40,25 +42,29 @@
 #define CLAPOS 0
 
 // APDU buffer getters
-#define APDU_CLA() (G_io_apdu_buffer[CLAPOS])
-#define APDU_CMD() (G_io_apdu_buffer[CMDPOS])
-#define APDU_OP() (G_io_apdu_buffer[OP])
-#define APDU_TXLEN() (G_io_apdu_buffer[TXLEN])
-#define APDU_AT(pos) (G_io_apdu_buffer[pos])
+#define APDU_CLA() (communication_get_msg_buffer()[CLAPOS])
+#define APDU_CMD() (communication_get_msg_buffer()[CMDPOS])
+#define APDU_OP() (communication_get_msg_buffer()[OP])
+#define APDU_TXLEN() (communication_get_msg_buffer()[TXLEN])
+#define APDU_AT(pos) (communication_get_msg_buffer()[pos])
 
 // APDU buffer setters
-#define SET_APDU_CLA() (G_io_apdu_buffer[CLAPOS] = CLA)
-#define SET_APDU_CMD(cmd) (G_io_apdu_buffer[CMDPOS] = (cmd))
-#define SET_APDU_OP(op) (G_io_apdu_buffer[OP] = (op))
-#define SET_APDU_TXLEN(len) (G_io_apdu_buffer[TXLEN] = (len))
-#define SET_APDU_AT(pos, value) (G_io_apdu_buffer[pos] = (value))
+#define SET_APDU_CLA() (communication_get_msg_buffer()[CLAPOS] = CLA)
+#define SET_APDU_CMD(cmd) (communication_get_msg_buffer()[CMDPOS] = (cmd))
+#define SET_APDU_OP(op) (communication_get_msg_buffer()[OP] = (op))
+#define SET_APDU_TXLEN(len) (communication_get_msg_buffer()[TXLEN] = (len))
+#define SET_APDU_AT(pos, value) (communication_get_msg_buffer()[pos] = (value))
 
 // Get pointer to payload within APDU buffer.
 // No args, so it can be treated like an array pointer.
-#define APDU_DATA_PTR (G_io_apdu_buffer + DATA)
+#define APDU_DATA_PTR (communication_get_msg_buffer() + DATA)
 
+// Total size of APDU
+#define APDU_TOTAL_SIZE (communication_get_msg_buffer_size())
+// Size of APDU elements
+#define APDU_ELEMENT_SIZE (sizeof(communication_get_msg_buffer()[0]))
 // Total size of APDU data part
-#define APDU_TOTAL_DATA_SIZE (sizeof(G_io_apdu_buffer) - DATA)
+#define APDU_TOTAL_DATA_SIZE (communication_get_msg_buffer_size() - DATA)
 // Total size of APDU data part for outputting
 // (need to leave space for result code)
 #define APDU_RESULT_CODE_SIZE 2

ledger/src/common/src/memutil.h

@@ -26,9 +26,8 @@
 #define __MEMUTIL_H
 
 #include <stdint.h>
-#include <stdbool.h>
 
-#include "os.h"
+#include "common_requirements.h"
 
 #define MEMMOVE_ZERO_OFFSET 0
 
@@ -54,7 +53,7 @@ __attribute__((always_inline)) static inline int safe_memmove(
 
         return false;
     } else {
-        os_memmove(
+        platform_memmove(
             (unsigned char *)dst + dst_off, (unsigned char *)src + src_off, n);
         return true;
     }

ledger/src/common/src/runtime.h

@@ -25,10 +25,27 @@
 #ifndef __RUNTIME_H
 #define __RUNTIME_H
 
-#ifdef HSM_SIMULATOR
+#if defined(HSM_PLATFORM_LEDGER)
+
+// We can't include any HAL headers here because
+// the Ledger UI does not know anything about it
+#include "os.h"
+
+#define NON_VOLATILE const
+
+#elif defined(HSM_PLATFORM_X86)
+
+#include "hal/platform.h"
+#include "hal/exceptions.h"
+
+#include "ui_deps.h"
+
+#define PIC(x) (x)
+
 #define NON_VOLATILE
+
 #else
-#define NON_VOLATILE const
+    #error "HSM Platform undefined"
 #endif
 
 #endif // __RUNTIME_H

ledger/src/hal/include/hal/communication.h

@@ -0,0 +1,75 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 RSK Labs 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.
+ */
+
+#ifndef __HAL_COMMUNICATION_H
+#define __HAL_COMMUNICATION_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * @brief Initializes the communication module
+ *
+ * @param msg_buffer The buffer to use for communication
+ * @param msg_buffer_size The size of the message buffer in bytes
+ * 
+ * @returns whether the initialisation succeeded
+ */
+bool communication_init(unsigned char* msg_buffer, size_t msg_buffer_size);
+
+/**
+ * @brief Get a pointer to the message buffer
+ * 
+ * @returns a pointer to the message buffer
+ */
+unsigned char* communication_get_msg_buffer();
+
+/**
+ * @brief Get the message buffer size
+ * 
+ * @returns the message buffer size
+ */
+size_t communication_get_msg_buffer_size();
+
+/**
+ * @brief Exchanges bytes with the host. This function blocks until the host sends a
+ * message.
+ *
+ *  The message exchanges data with the host using the msg_buffer. If there are any bytes
+ *  to transmit, they are transmitted first. After that the function blocks until a new
+ *  message is received from the host.
+ *
+ * @param tx The number of bytes sent to the host
+ *
+ * @returns the number of bytes received from the host
+ */
+unsigned short communication_io_exchange(unsigned short tx);
+
+/**
+ * @brief Finalizes the communication module
+ */
+void communication_finalize(void);
+
+#endif // __HAL_COMMUNICATION_H

ledger/src/hal/include/hal/endorsement.h

@@ -0,0 +1,71 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 RSK Labs 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.
+ */
+
+#ifndef __HAL_ENDORSEMENT_H
+#define __HAL_ENDORSEMENT_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * @brief Endorses the given message
+ * 
+ * @param msg The message to attest
+ * @param msg_size The size of the message to attest
+ * @param signature_out Where the signature should be output
+ * @param signature_out_length [in/out] the length of the output buffer /
+ *                          length of the produced signature
+ * 
+ * @returns whether endorsement succeeded
+ */
+bool endorsement_sign(uint8_t* msg, size_t msg_size,
+                      uint8_t* signature_out,
+                      uint8_t* signature_out_length);
+
+/**
+ * @brief Grabs the hash of the currently running code
+ * 
+ * @param code_hash_out Where the code hash should be output
+ * @param code_hash_out_length [in/out] the length of the output buffer /
+ *                          length of the produced code hash
+ * 
+ * @returns whether code hash gathering succeeded
+ */
+bool endorsement_get_code_hash(uint8_t* code_hash_out,
+                               uint8_t* code_hash_out_length);
+
+/**
+ * @brief Grabs the endorsement public key
+ * 
+ * @param public_key_out Where the public key should be output
+ * @param public_key_out_length [in/out] the length of the output buffer /
+ *                          length of the produced public key
+ * 
+ * @returns whether public key gathering succeeded
+ */
+bool endorsement_get_public_key(uint8_t* public_key_out,
+                                uint8_t* public_key_out_length);
+
+#endif // __HAL_ENDORSEMENT_H