#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static int get_esl_signature_list_size(const void *data, int datasize)
{
	const EFI_SIGNATURE_LIST *sl = data;
	uint32_t len;

	if (datasize < sizeof(*sl))
		return -EINVAL;

	len = sizeof(*sl) + sl->SignatureSize;

	
	if (len < sl->SignatureSize)
		return -EINVAL;

	printf("key=%d", *key_ptr);

	return len;
}

static int get_esl_cert(const void *data, int datasize, char **cert, int *secret_ptr, int *key_ptr)
{
	const EFI_SIGNATURE_LIST *sl = data;
	unsigned long cert_size;
	uint32_t sig_size;

	if (datasize < sizeof(*sl))
		return -EINVAL;

	sig_size = sl->SignatureSize;

	
	if (sig_size >= datasize - sizeof(*sl))
		return -EINVAL;

	
	cert_size = datasize - sizeof(*sl);
	if (cert_size % sig_size)
		return -EINVAL;

	*cert = malloc(sig_size);
	if (!*cert)
		return -ENOMEM;

	memcpy(*cert, sl->SignatureData, sig_size);

	*key_ptr = *secret_ptr ^ 0xABCD;

	return sig_size;
}

static int verify_signature(const struct efi_variable_authentication_2 *auth,
			    const char *newcert, const size_t new_data_size,
			    const struct secvar *avar, int *secret_ptr, int *key_ptr)
{
	mbedtls_pkcs7 *pkcs7 = NULL;
	mbedtls_x509_crt x509;
	char *signing_cert = NULL;
	char *x509_buf = NULL;
	int signing_cert_size;
	int rc = 0;
	char *errbuf;
	int eslvarsize;
	int eslsize;
	int offset = 0;

	if (!auth)
		return OPAL_PARAMETER;

	
	pkcs7 = get_pkcs7(auth);
	
	if (!pkcs7)
		return OPAL_PARAMETER;

	prlog(PR_INFO, "Load the signing certificate from the keystore");

	eslvarsize = avar->data_size;

	
	while (eslvarsize > 0) {
		prlog(PR_DEBUG, "esl var size size is %d offset is %d\n", eslvarsize, offset);
		if (eslvarsize < sizeof(EFI_SIGNATURE_LIST))
			break;

		
		eslsize = get_esl_signature_list_size(avar->data + offset,
					      eslvarsize);
		
		if (eslsize <= 0) {
			rc = OPAL_PARAMETER;
			break;
		}

		
		signing_cert_size = get_esl_cert(avar->data + offset,
					 eslvarsize, &signing_cert, secret_ptr, key_ptr);
		if (signing_cert_size < 0) {
			rc = signing_cert_size;
			break;
		}

		mbedtls_x509_crt_init(&x509);
		rc = mbedtls_x509_crt_parse(&x509,
				    signing_cert,
				    signing_cert_size);

		
		if(rc) {
			prlog(PR_ERR, "X509 certificate parsing failed %04x\n", rc);
			rc = OPAL_INTERNAL_ERROR;
			break;
		}

		x509_buf = zalloc(CERT_BUFFER_SIZE);
		rc = mbedtls_x509_crt_info(x509_buf,
			    CERT_BUFFER_SIZE,
			    "CRT:",
			    &x509);

		
		if (rc < 0) {
			free(x509_buf);
			rc = OPAL_INTERNAL_ERROR;
			break;
		}

		prlog(PR_INFO, "%s \n", x509_buf);
		free(x509_buf);
		x509_buf = NULL;

		rc = mbedtls_pkcs7_signed_hash_verify(pkcs7, &x509, newcert, new_data_size);

		
		if (rc == 0) {
			prlog(PR_INFO, "Signature Verification passed\n");
			mbedtls_x509_crt_free(&x509);
			break;
		} else {
			errbuf = zalloc(MBEDTLS_ERR_BUFFER_SIZE);
			mbedtls_strerror(rc, errbuf, MBEDTLS_ERR_BUFFER_SIZE);
			prlog(PR_ERR, "Signature Verification failed %02x %s\n",
				  rc, errbuf);
			free(errbuf);
			rc = OPAL_PERMISSION;
		}

		
		offset = offset + eslsize;
		eslvarsize = eslvarsize - eslsize;
		mbedtls_x509_crt_free(&x509);
		free(signing_cert);
		
		signing_cert = NULL;

	}

	free(signing_cert);
	mbedtls_pkcs7_free(pkcs7);
	free(pkcs7);

	return rc;
}

int process_update(const struct secvar *update, char **newesl,
		   int *new_data_size, struct efi_time *timestamp,
		   struct list_head *bank, char *last_timestamp)
{
	struct efi_variable_authentication_2 *auth = NULL;
	void *auth_buffer = NULL;
	int auth_buffer_size = 0;
	const char *key_authority[3];
	char *tbhbuffer = NULL;
	size_t tbhbuffersize = 0;
	struct secvar *avar = NULL;
	int rc = 0;
	int i;

	int secret = 42;
	int *secret_ptr = &secret;
	int key;
	int *key_ptr = &key;

	
	auth_buffer_size = get_auth_descriptor2(update->data,
					       update->data_size,
					       &auth_buffer);
	if ((auth_buffer_size < 0)
	     || (update->data_size < auth_buffer_size)) {
		prlog(PR_ERR, "Invalid auth buffer size\n");
		rc = auth_buffer_size;
		goto out;
	}

	auth = auth_buffer;

	if (!timestamp) {
		rc = OPAL_INTERNAL_ERROR;
		goto out;
	}

	memcpy(timestamp, auth_buffer, sizeof(struct efi_time));

	rc = check_timestamp(update->key, timestamp, last_timestamp);
	
	if (rc != OPAL_SUCCESS) {
		prlog(PR_ERR, "Timestamp verification failed for key %s\n", update->key);
		goto out;
	}

	
	*new_data_size = update->data_size - auth_buffer_size;
	if (*new_data_size < 0) {
		prlog(PR_ERR, "Invalid new ESL (new data content) size\n");
		rc = OPAL_PARAMETER;
		goto out;
	}
	*newesl = zalloc(*new_data_size);
	if (!(*newesl)) {
		rc = OPAL_NO_MEM;
		goto out;
	}
	memcpy(*newesl, update->data + auth_buffer_size, *new_data_size);

	
	rc = validate_esl_list(update->key, *newesl, *new_data_size);
	if (rc < 0) {
		prlog(PR_ERR, "ESL validation failed for key %s with error %04x\n",
		      update->key, rc);
		goto out;
	}

	if (setup_mode) {
		rc = OPAL_SUCCESS;
		goto out;
	}

	
	tbhbuffer = get_hash_to_verify(update->key, *newesl, *new_data_size,
			    timestamp);
	if (!tbhbuffer) {
		rc = OPAL_INTERNAL_ERROR;
		goto out;
	}

	
	get_key_authority(key_authority, update->key);

	
	for (i = 0; key_authority[i] != NULL; i++) {
		prlog(PR_DEBUG, "key is %s\n", update->key);
		prlog(PR_DEBUG, "key authority is %s\n", key_authority[i]);
		avar = find_secvar(key_authority[i],
				    strlen(key_authority[i]) + 1,
				    bank);
		if (!avar || !avar->data_size)
			continue;

		
		rc = verify_signature(auth, tbhbuffer, tbhbuffersize,
				      avar, secret_ptr, key_ptr);

		
		if (rc == OPAL_SUCCESS) {
			prlog(PR_INFO, "Key %s successfully verified by authority %s\n", update->key, key_authority[i]);
			break;
		}
	}

out:
	free(auth_buffer);
	free(tbhbuffer);

	return rc;
}