diff --git a/action-authorization/Android.mk b/action-authorization/Android.mk
new file mode 100644
index 0000000..e2ebd60
--- /dev/null
+++ b/action-authorization/Android.mk
@@ -0,0 +1,16 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_LDLIBS_windows := -lws2_32 -lgdi32
+LOCAL_LDLIBS_linux := -lrt -ldl -lpthread
+LOCAL_CXX_STL := libc++_static
+
+LOCAL_MODULE := action-authorization
+#LOCAL_MODULE_HOST_OS := linux windows
+LOCAL_SRC_FILES := action-authorization.c
+LOCAL_C_INCLUDES := external/boringssl/src/include/
+LOCAL_CFLAGS := -Wall -Wextra -Werror
+LOCAL_STATIC_LIBRARIES := libcrypto
+
+include $(BUILD_HOST_EXECUTABLE)
diff --git a/action-authorization/Makefile b/action-authorization/Makefile
new file mode 100644
index 0000000..67986d0
--- /dev/null
+++ b/action-authorization/Makefile
@@ -0,0 +1,22 @@
+
+CC = $(CROSS_COMPILE)gcc
+LD = $(CROSS_COMPILE)ld
+
+LDLIBS = -lcrypto
+
+EXEC = action-authorization
+OBJS = action-authorization.o
+
+all: $(EXEC)
+
+$(EXEC): $(OBJS)
+	$(CC) $(LDFLAGS) -o $@ $(OBJS) $(LDLIBS)
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+%.o: %.cpp
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+clean:
+	-rm -f $(EXEC) *.elf *.o
diff --git a/action-authorization/action-authorization.c b/action-authorization/action-authorization.c
new file mode 100644
index 0000000..9de5405
--- /dev/null
+++ b/action-authorization/action-authorization.c
@@ -0,0 +1,242 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed 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 <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <libgen.h>
+#include <getopt.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <ctype.h>
+#include <sys/time.h>
+#include <openssl/pem.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+#include "rma_certificate.h"
+
+
+static void usage(char *cmd, int status)
+{
+	FILE *out = status == EXIT_SUCCESS ? stdout : stderr;
+
+	fprintf(out, "Usage: %s [OPTIONS]\n"
+		"	\n"
+		"	Produce a answer message to a fastboot get-action-nonce.\n"
+		"	This message can be sent using the fastboot flash action-authorization\n"
+		"	<file> command.\n"
+		"	\n"
+		"	--oak-cert, -O <file>          OAK certificate (PEM)\n"
+		"	--oak-private-key, -K <file>   private key file (PEM)\n"
+		"	--message, -M <string>         message received from get-action-nonce\n"
+		"	fastboot command\n"
+		"	--output-file, -F <file>       output file for the PKCS7 message\n"
+		"	--help, -h                     display this help and exit\n", cmd);
+
+	exit(status);
+}
+
+static struct option long_options[] = {
+	{"help", no_argument, 0, 'h'},
+	{"oak-cert", required_argument, 0, 'O'},
+	{"oak-private-key", required_argument, 0, 'K'},
+	{"message", required_argument, 0, 'M'},
+	{"output-file", required_argument, 0, 'F' },
+	{0, 0, 0, 0}
+};
+
+static int save_file(const char *file, char *buf, int len)
+{
+	FILE *fp;
+
+	fp = fopen(file, "wb");
+	if (fp == NULL)
+		return -1;
+
+	fwrite(buf, 1, len, fp);
+	fclose(fp);
+	return 0;
+}
+
+static X509 *load_public_key_file(const char *file)
+{
+	X509 *cert;
+	BIO *cert_bio;
+
+	cert_bio = BIO_new_file(file, "rb");
+	if (!cert_bio)
+		return NULL;
+
+	cert = PEM_read_bio_X509_AUX(cert_bio, NULL, NULL, NULL);
+	BIO_free(cert_bio);
+
+	return cert;
+}
+
+EVP_PKEY *load_private_key_file(const char *file)
+{
+	EVP_PKEY *private_key;
+	BIO *key_bio;
+
+	key_bio = BIO_new_file(file, "rb");
+	if (!key_bio)
+		return NULL;
+
+	private_key = d2i_PrivateKey_bio(key_bio, NULL);
+	BIO_free(key_bio);
+	if (private_key == NULL)
+		return NULL;
+
+	return private_key;
+}
+
+static int generate_rma_cerificate(const char *key_file, const char *cert_file, char *nonce, const char *out_file)
+{
+	EVP_MD_CTX mdctx;
+	RMA_CERTIFICATE *rma_cert = NULL;
+	EVP_PKEY *private_key = NULL;
+	X509 *x509 = NULL;
+	unsigned char *sign_value = NULL;
+	char *der = NULL;
+	char *p;
+	int sign_len;
+	int len;
+	int ret = -1;
+
+	do {
+		private_key = load_private_key_file(key_file);
+		if (private_key == NULL) {
+			fprintf(stdout, "Failed to load the private key '%s'\n", key_file);
+			break;
+		}
+
+		x509 = load_public_key_file(cert_file);
+		if (x509 == NULL) {
+			fprintf(stdout, "Failed to load the public key '%s'\n", cert_file);
+			break;
+		}
+
+		rma_cert = RMA_CERTIFICATE_new();
+		if (rma_cert == NULL)
+			break;
+
+		rma_cert->x509 = x509;
+		x509 = NULL;
+		ASN1_OCTET_STRING_set(rma_cert->nonce, (const unsigned char *)nonce, strlen(nonce));
+
+		EVP_MD_CTX_init(&mdctx);
+		if (EVP_SignInit_ex(&mdctx, EVP_sha256(), NULL) <= 0)
+			break;
+
+		if (EVP_SignUpdate(&mdctx, rma_cert->nonce->data, rma_cert->nonce->length) <= 0)
+			break;
+
+		sign_len = EVP_PKEY_size(private_key);
+		sign_value = malloc(sign_len);
+		if (sign_value == NULL)
+			break;
+		if (EVP_SignFinal(&mdctx, sign_value, &sign_len, private_key) <= 0) {
+			fprintf(stdout, "error for EVP_SignFinal\n");
+			break;
+		}
+		ASN1_STRING_set0(rma_cert->digest, sign_value, sign_len);
+		sign_value = NULL;
+		EVP_MD_CTX_cleanup(&mdctx);
+
+		len = i2d_RMA_CERTIFICATE(rma_cert, NULL);
+		der = (char *)malloc(len);
+		if (der == NULL)
+			break;
+
+		p = der;
+		len = i2d_RMA_CERTIFICATE(rma_cert, (unsigned char **)&p);
+		save_file(out_file, der, len);
+		ret = EXIT_SUCCESS;
+	}	while (0);
+
+	if (der != NULL)
+		free(der);
+	if (sign_value != NULL)
+		free(sign_value);
+	if (private_key)
+		EVP_PKEY_free(private_key);
+	if (x509 != NULL)
+		X509_free(x509);
+	if (rma_cert != NULL)
+		RMA_CERTIFICATE_free(rma_cert);
+
+	return ret;
+}
+
+int main(int argc, char **argv)
+{
+	char *key_file = NULL;
+	char *cert_file = NULL;
+	char *out_file = NULL;
+	char *message = NULL;
+	char c, *cmd;
+	int option_index = 0;
+	int ret = EXIT_FAILURE;
+
+	cmd = basename(argv[0]);
+	while (1) {
+		c = getopt_long(argc, argv, "hO:K:A:M:F:P:V",
+				long_options, &option_index);
+		if (c == -1)
+			break;
+		switch (c) {
+		case 0:
+			break;
+
+		case 'h':
+			usage(cmd, EXIT_SUCCESS);
+			break;
+
+		case 'O':
+			cert_file = optarg;
+			break;
+
+		case 'K':
+			key_file = optarg;
+			break;
+
+		case 'M':
+			message = optarg;
+			break;
+
+		case 'F':
+			out_file = optarg;
+			break;
+
+		default:
+			usage(cmd, EXIT_FAILURE);
+			break;
+		}
+	}
+
+	if (!key_file || !cert_file || !out_file || !message)
+		usage(cmd, EXIT_FAILURE);
+
+	ret = generate_rma_cerificate(key_file, cert_file, message, out_file);
+	if (ret == EXIT_SUCCESS)
+		fprintf(stdout, "'%s' successfully generated.\n", out_file);
+	else
+		fprintf(stdout, "'%s' generate failed.\n", out_file);
+
+	return ret;
+}
+
diff --git a/action-authorization/rma_certificate.h b/action-authorization/rma_certificate.h
new file mode 100644
index 0000000..6f02c9e
--- /dev/null
+++ b/action-authorization/rma_certificate.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed 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.
+ */
+
+#ifndef __RMA_CERTIFICATE_H__
+#define __RMA_CERTIFICATE_H__
+
+#include <openssl/asn1.h>
+#include <openssl/asn1t.h>
+#include <openssl/conf.h>
+
+typedef struct RMA_CERTIFICATE_st {
+	X509 *x509;
+	ASN1_OCTET_STRING *nonce;
+	ASN1_OCTET_STRING *digest;
+} RMA_CERTIFICATE;
+DECLARE_ASN1_FUNCTIONS(RMA_CERTIFICATE)
+
+ASN1_SEQUENCE(RMA_CERTIFICATE) = {
+	ASN1_SIMPLE(RMA_CERTIFICATE, x509, X509),
+	ASN1_SIMPLE(RMA_CERTIFICATE, nonce, ASN1_OCTET_STRING),
+	ASN1_SIMPLE(RMA_CERTIFICATE, digest, ASN1_OCTET_STRING),
+} ASN1_SEQUENCE_END(RMA_CERTIFICATE)
+IMPLEMENT_ASN1_FUNCTIONS(RMA_CERTIFICATE)
+
+#endif // __RMA_CERTIFICATE_H__
+