extra: Add Dummy RMA reset auth challenge-response application

Dummy RMA reset application that's used by the RMA Server
Side implementer. Currently everything is hard coded in the app.
This application will be replaced when the actual app is ready.

BUG=b:37952913
BRANCH=none
TEST=make buildall -j
     ./rma_test
     Board Id:
     Z Z C R

     Device Id:
     T H X 01 01 03 08 fe

     Server Key Id:
     10

     Server Private Key:
     47 3b a5 db c4 bb d6 77
     20 bd d8 bd c8 7a bb 07
     03 79 ba 7b 52 8c ec b3
     4d aa 69 f5 65 b4 31 ad

     Server Public Key:
     03 ae 2d 2c 06 23 e0 73
     0d d3 b7 92 ac 54 c5 fd
     7e 9c f0 a8 eb 7e 2a b5
     db f4 79 5f 8a 0f 28 3f

     Challenge:
     CC5QQ LALUS BUPJC TWSYN PAPPN AUEVZ HEMUD GD5DK
     DSM5C VH4SZ LJAZL GDUYM U4JPK FJUCA 2AEAS GCH8W

     Authorization Code:
     P5PSCTS6

     Challenge String:
https://www.google.com/chromeos/partner/console/cr50reset/request?challenge=CC5QQLALUSBUPJCTWSYNPAPPNAUEVZHEMUDGD5DKDSM5CVH4SZLJAZLGDUYMU4JPKFJUCA2AEASGCH8W&hwid=HWIDTEST2082

     Enter Authorization Code: abcd

     Code is invalid

     Enter Authorization Code: P5PSCTS6
     Code Accepted

Change-Id: Id4141861b53745cf7bb67a885fa01dd6f4b4cd04
Signed-off-by: Sam Hurst <shurst@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/622283
Commit-Ready: Sam Hurst <shurst@google.com>
Tested-by: Sam Hurst <shurst@google.com>
Reviewed-by: Michael Tang <ntang@chromium.org>

3 files changed, 243 insertions, 0 deletions

diff --git a/extra/rma_reset/Makefile b/extra/rma_reset/Makefile
new file mode 100644
index 0000000000..4332ce203d
--- /dev/null
+++ b/extra/rma_reset/Makefile
@@ -0,0 +1,51 @@
+# Copyright 2017 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+PROGRAM := rma_reset
+SOURCE  := $(PROGRAM).c
+OBJS    := curve25519.o curve25519-generic.o sha256.o base32.o
+LIBS    :=
+LFLAGS  :=
+CFLAGS  := -std=gnu99 \
+	-g3 \
+	-O3 \
+        -Wall \
+        -Werror \
+        -Wpointer-arith \
+        -Wcast-align \
+        -Wcast-qual \
+        -Wundef \
+        -Wsign-compare \
+        -Wredundant-decls \
+        -Wmissing-declarations
+
+#
+# Add libusb-1.0 required flags
+#
+INCLUDE=-I. -I../../ -I../../test -I../../include -I../../chip/host
+LIBS    += -lcrypto -lssl
+CFLAGS  += ${INCLUDE}
+STANDALONE_FLAGS=${INCLUDE} -ffreestanding -fno-builtin \
+                        -Ibuiltin/ -D"__keep= "
+
+$(PROGRAM): $(SOURCE) $(OBJS) Makefile
+	gcc $(CFLAGS) $(SOURCE) $(LFLAGS) $(LIBS) $(OBJS) -o $@
+
+curve25519-generic.o: ../../common/curve25519-generic.c
+	gcc $(STANDALONE_FLAGS) -c -o curve25519-generic.o \
+				../../common/curve25519-generic.c
+
+curve25519.o: ../../common/curve25519.c
+	gcc $(STANDALONE_FLAGS) -c -o curve25519.o ../../common/curve25519.c
+
+sha256.o: ../../common/sha256.c
+	gcc $(STANDALONE_FLAGS) -c -o sha256.o ../../common/sha256.c
+
+base32.o: ../../common/base32.c
+	gcc $(STANDALONE_FLAGS) -c -o base32.o ../../common/base32.c
+
+.PHONY: clean
+
+clean:
+	rm -rf *.o $(PROGRAM) *~
diff --git a/extra/rma_reset/board.h b/extra/rma_reset/board.h
new file mode 100644
index 0000000000..f969ad0c56
--- /dev/null
+++ b/extra/rma_reset/board.h
@@ -0,0 +1,11 @@
+/* Copyright 2017 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_BOARD_H
+#define __CROS_EC_BOARD_H
+
+#define CONFIG_RNG
+
+#endif /* __CROS_EC_BOARD_H */
diff --git a/extra/rma_reset/rma_reset.c b/extra/rma_reset/rma_reset.c
new file mode 100644
index 0000000000..0c72894f13
--- /dev/null
+++ b/extra/rma_reset/rma_reset.c
@@ -0,0 +1,181 @@
+/* Copyright 2017 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#define __packed __attribute__((packed))
+#include "rma_auth.h"
+#include "curve25519.h"
+#include "sha256.h"
+#include "base32.h"
+
+#define SERVER_ADDRESS	"https://www.google.com/chromeos/partner/console/cr50reset/request"
+
+/* Server public key and key ID */
+static uint8_t server_pri_key[32] = RMA_TEST_SERVER_PRIVATE_KEY;
+static uint8_t server_pub_key[32] = RMA_TEST_SERVER_PUBLIC_KEY;
+static uint8_t server_key_id = RMA_TEST_SERVER_KEY_ID;
+static uint8_t board_id[4] = {'Z', 'Z', 'C', 'R'};
+static uint8_t device_id[8] = {'T', 'H', 'X', 1, 1, 3, 8, 0xfe};
+
+static char challenge[RMA_CHALLENGE_BUF_SIZE];
+static char authcode[RMA_AUTHCODE_BUF_SIZE];
+
+void panic_assert_fail(const char *fname, int linenum);
+void rand_bytes(void *buffer, size_t len);
+int safe_memcmp(const void *s1, const void *s2, size_t size);
+
+void panic_assert_fail(const char *fname, int linenum)
+{
+	printf("\nASSERTION FAILURE at %s:%d\n", fname, linenum);
+}
+
+int safe_memcmp(const void *s1, const void *s2, size_t size)
+{
+	const uint8_t *us1 = s1;
+	const uint8_t *us2 = s2;
+	int result = 0;
+
+	if (size == 0)
+		return 0;
+
+	while (size--)
+		result |= *us1++ ^ *us2++;
+
+	return result != 0;
+}
+
+void rand_bytes(void *buffer, size_t len)
+{
+	int random_togo = 0;
+	uint32_t buffer_index = 0;
+	uint32_t random_value;
+	uint8_t *buf = (uint8_t *) buffer;
+
+	while (buffer_index < len) {
+		if (!random_togo) {
+			random_value = rand();
+			random_togo = sizeof(random_value);
+		}
+		buf[buffer_index++] = random_value >>
+			((random_togo-- - 1) * 8);
+	}
+}
+
+int rma_create_challenge(void)
+{
+	uint8_t temp[32];   /* Private key or HMAC */
+	uint8_t secret[32];
+	struct rma_challenge c;
+	uint8_t *cptr = (uint8_t *)&c;
+
+	/* Clear the current challenge and authcode, if any */
+	memset(challenge, 0, sizeof(challenge));
+	memset(authcode, 0, sizeof(authcode));
+
+	memset(&c, 0, sizeof(c));
+	c.version_key_id = RMA_CHALLENGE_VKID_BYTE(
+		RMA_CHALLENGE_VERSION, server_key_id);
+
+	memcpy(c.board_id, board_id, sizeof(c.board_id));
+	memcpy(c.device_id, device_id, sizeof(c.device_id));
+
+	/* Calculate a new ephemeral key pair */
+	X25519_keypair(c.device_pub_key, temp);
+
+	/* Encode the challenge */
+	if (base32_encode(challenge, sizeof(challenge), cptr, 8 * sizeof(c), 9))
+		return 1;
+
+	/* Calculate the shared secret */
+	X25519(secret, temp, server_pub_key);
+
+	/*
+	 * Auth code is a truncated HMAC of the ephemeral public key, BoardID,
+	 * and DeviceID.  Those are all in the right order in the challenge
+	 * struct, after the version/key id byte.
+	 */
+	hmac_SHA256(temp, secret, sizeof(secret), cptr + 1, sizeof(c) - 1);
+	if (base32_encode(authcode, sizeof(authcode), temp,
+			  RMA_AUTHCODE_CHARS * 5, 0))
+		return 1;
+
+	return 0;
+}
+
+int rma_try_authcode(const char *code)
+{
+	return safe_memcmp(authcode, code, RMA_AUTHCODE_CHARS);
+}
+
+static void print_params(void)
+{
+	int i;
+
+	printf("\nBoard Id:\n");
+	for (i = 0; i < 4; i++)
+		printf("%c ", board_id[i]);
+
+	printf("\n\nDevice Id:\n");
+	for (i = 0; i < 3; i++)
+		printf("%c ", device_id[i]);
+	for (i = 3; i < 8; i++)
+		printf("%02x ", device_id[i]);
+
+	printf("\n\nServer Key Id:\n");
+	printf("%02x", server_key_id);
+
+	printf("\n\nServer Private Key:\n");
+	for (i = 0; i < 32; i++)
+		printf("%02x%c", server_pri_key[i], ((i + 1) % 8) ? ' ':'\n');
+
+	printf("\nServer Public Key:\n");
+	for (i = 0; i < 32; i++)
+		printf("%02x%c", server_pub_key[i], ((i + 1) % 8) ? ' ':'\n');
+
+	printf("\nChallenge:\n");
+	for (i = 0; i < RMA_CHALLENGE_CHARS; i++) {
+		printf("%c", challenge[i]);
+		if (((i + 1) % 5) == 0)
+			printf(" ");
+		if (((i + 1) % 40) == 0)
+			printf("\n");
+	}
+
+	printf("\nAuthorization Code:\n");
+	for (i = 0; i < RMA_AUTHCODE_BUF_SIZE; i++)
+		printf("%c", authcode[i]);
+
+	printf("\n\nChallenge String:\n");
+	printf("%s?challenge=", SERVER_ADDRESS);
+	for (i = 0; i < RMA_CHALLENGE_CHARS; i++)
+		printf("%c", challenge[i]);
+	printf("&hwid=HWIDTEST2082\n");
+
+	printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+	char code[25];
+	int ret;
+
+	rma_create_challenge();
+	print_params();
+
+	do {
+		printf("Enter Authorization Code: ");
+		fgets(code, 25, stdin);
+		ret = rma_try_authcode(code);
+		if (ret != 0)
+			printf("\n\nCode is invalid\n\n");
+	} while (ret != 0);
+
+	printf("Code Accepted\n");
+
+	return 0;
+}