// SPDX-License-Identifier: GPL-2.0+

  /*
   * Copyright (c) 2013, Google Inc.

   */
  
  #include "mkimage.h"
  #include <stdio.h>
  #include <string.h>

  #include <image.h>
  #include <time.h>

  #include <openssl/bn.h>

  #include <openssl/rsa.h>
  #include <openssl/pem.h>
  #include <openssl/err.h>
  #include <openssl/ssl.h>
  #include <openssl/evp.h>

  #include <openssl/engine.h>

  
  #if OPENSSL_VERSION_NUMBER >= 0x10000000L
  #define HAVE_ERR_REMOVE_THREAD_STATE
  #endif

  #if OPENSSL_VERSION_NUMBER < 0x10100000L || \
  	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)

  static void RSA_get0_key(const RSA *r,
                   const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)
  {
     if (n != NULL)
         *n = r->n;
     if (e != NULL)
         *e = r->e;
     if (d != NULL)
         *d = r->d;
  }
  #endif

  static int rsa_err(const char *msg)
  {
  	unsigned long sslErr = ERR_get_error();
  
  	fprintf(stderr, "%s", msg);
  	fprintf(stderr, ": %s
  ",
  		ERR_error_string(sslErr, 0));
  
  	return -1;
  }
  
  /**

   * rsa_pem_get_pub_key() - read a public key from a .crt file

   *
   * @keydir:	Directory containins the key
   * @name	Name of key file (will have a .crt extension)
   * @rsap	Returns RSA object, or NULL on failure
   * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
   */

  static int rsa_pem_get_pub_key(const char *keydir, const char *name, RSA **rsap)

  {
  	char path[1024];
  	EVP_PKEY *key;
  	X509 *cert;
  	RSA *rsa;
  	FILE *f;
  	int ret;
  
  	*rsap = NULL;
  	snprintf(path, sizeof(path), "%s/%s.crt", keydir, name);
  	f = fopen(path, "r");
  	if (!f) {
  		fprintf(stderr, "Couldn't open RSA certificate: '%s': %s
  ",
  			path, strerror(errno));
  		return -EACCES;
  	}
  
  	/* Read the certificate */
  	cert = NULL;
  	if (!PEM_read_X509(f, &cert, NULL, NULL)) {
  		rsa_err("Couldn't read certificate");
  		ret = -EINVAL;
  		goto err_cert;
  	}
  
  	/* Get the public key from the certificate. */
  	key = X509_get_pubkey(cert);
  	if (!key) {
  		rsa_err("Couldn't read public key
  ");
  		ret = -EINVAL;
  		goto err_pubkey;
  	}
  
  	/* Convert to a RSA_style key. */
  	rsa = EVP_PKEY_get1_RSA(key);
  	if (!rsa) {
  		rsa_err("Couldn't convert to a RSA style key");

  		ret = -EINVAL;

  		goto err_rsa;
  	}
  	fclose(f);
  	EVP_PKEY_free(key);
  	X509_free(cert);
  	*rsap = rsa;
  
  	return 0;
  
  err_rsa:
  	EVP_PKEY_free(key);
  err_pubkey:
  	X509_free(cert);
  err_cert:
  	fclose(f);
  	return ret;
  }
  
  /**

   * rsa_engine_get_pub_key() - read a public key from given engine

   *

   * @keydir:	Key prefix
   * @name	Name of key
   * @engine	Engine to use
   * @rsap	Returns RSA object, or NULL on failure
   * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
   */
  static int rsa_engine_get_pub_key(const char *keydir, const char *name,
  				  ENGINE *engine, RSA **rsap)
  {
  	const char *engine_id;
  	char key_id[1024];
  	EVP_PKEY *key;
  	RSA *rsa;
  	int ret;
  
  	*rsap = NULL;
  
  	engine_id = ENGINE_get_id(engine);
  
  	if (engine_id && !strcmp(engine_id, "pkcs11")) {
  		if (keydir)
  			snprintf(key_id, sizeof(key_id),
  				 "pkcs11:%s;object=%s;type=public",
  				 keydir, name);
  		else
  			snprintf(key_id, sizeof(key_id),
  				 "pkcs11:object=%s;type=public",
  				 name);
  	} else {
  		fprintf(stderr, "Engine not supported
  ");
  		return -ENOTSUP;
  	}
  
  	key = ENGINE_load_public_key(engine, key_id, NULL, NULL);
  	if (!key)
  		return rsa_err("Failure loading public key from engine");
  
  	/* Convert to a RSA_style key. */
  	rsa = EVP_PKEY_get1_RSA(key);
  	if (!rsa) {
  		rsa_err("Couldn't convert to a RSA style key");
  		ret = -EINVAL;
  		goto err_rsa;
  	}
  
  	EVP_PKEY_free(key);
  	*rsap = rsa;
  
  	return 0;
  
  err_rsa:
  	EVP_PKEY_free(key);
  	return ret;
  }
  
  /**
   * rsa_get_pub_key() - read a public key
   *
   * @keydir:	Directory containing the key (PEM file) or key prefix (engine)
   * @name	Name of key file (will have a .crt extension)
   * @engine	Engine to use
   * @rsap	Returns RSA object, or NULL on failure
   * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
   */
  static int rsa_get_pub_key(const char *keydir, const char *name,
  			   ENGINE *engine, RSA **rsap)
  {
  	if (engine)
  		return rsa_engine_get_pub_key(keydir, name, engine, rsap);
  	return rsa_pem_get_pub_key(keydir, name, rsap);
  }
  
  /**
   * rsa_pem_get_priv_key() - read a private key from a .key file
   *
   * @keydir:	Directory containing the key

   * @name	Name of key file (will have a .key extension)
   * @rsap	Returns RSA object, or NULL on failure
   * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
   */

  static int rsa_pem_get_priv_key(const char *keydir, const char *name,
  				RSA **rsap)

  {
  	char path[1024];
  	RSA *rsa;
  	FILE *f;
  
  	*rsap = NULL;
  	snprintf(path, sizeof(path), "%s/%s.key", keydir, name);
  	f = fopen(path, "r");
  	if (!f) {
  		fprintf(stderr, "Couldn't open RSA private key: '%s': %s
  ",
  			path, strerror(errno));
  		return -ENOENT;
  	}
  
  	rsa = PEM_read_RSAPrivateKey(f, 0, NULL, path);
  	if (!rsa) {
  		rsa_err("Failure reading private key");
  		fclose(f);
  		return -EPROTO;
  	}
  	fclose(f);
  	*rsap = rsa;
  
  	return 0;
  }

  /**
   * rsa_engine_get_priv_key() - read a private key from given engine
   *
   * @keydir:	Key prefix
   * @name	Name of key
   * @engine	Engine to use
   * @rsap	Returns RSA object, or NULL on failure
   * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
   */
  static int rsa_engine_get_priv_key(const char *keydir, const char *name,
  				   ENGINE *engine, RSA **rsap)
  {
  	const char *engine_id;
  	char key_id[1024];
  	EVP_PKEY *key;
  	RSA *rsa;
  	int ret;
  
  	*rsap = NULL;
  
  	engine_id = ENGINE_get_id(engine);
  
  	if (engine_id && !strcmp(engine_id, "pkcs11")) {
  		if (keydir)
  			snprintf(key_id, sizeof(key_id),
  				 "pkcs11:%s;object=%s;type=private",
  				 keydir, name);
  		else
  			snprintf(key_id, sizeof(key_id),
  				 "pkcs11:object=%s;type=private",
  				 name);
  	} else {
  		fprintf(stderr, "Engine not supported
  ");
  		return -ENOTSUP;
  	}
  
  	key = ENGINE_load_private_key(engine, key_id, NULL, NULL);
  	if (!key)
  		return rsa_err("Failure loading private key from engine");
  
  	/* Convert to a RSA_style key. */
  	rsa = EVP_PKEY_get1_RSA(key);
  	if (!rsa) {
  		rsa_err("Couldn't convert to a RSA style key");
  		ret = -EINVAL;
  		goto err_rsa;
  	}
  
  	EVP_PKEY_free(key);
  	*rsap = rsa;
  
  	return 0;
  
  err_rsa:
  	EVP_PKEY_free(key);
  	return ret;
  }
  
  /**
   * rsa_get_priv_key() - read a private key
   *
   * @keydir:	Directory containing the key (PEM file) or key prefix (engine)
   * @name	Name of key
   * @engine	Engine to use for signing
   * @rsap	Returns RSA object, or NULL on failure
   * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
   */
  static int rsa_get_priv_key(const char *keydir, const char *name,
  			    ENGINE *engine, RSA **rsap)
  {
  	if (engine)
  		return rsa_engine_get_priv_key(keydir, name, engine, rsap);
  	return rsa_pem_get_priv_key(keydir, name, rsap);
  }

  static int rsa_init(void)
  {
  	int ret;

  #if OPENSSL_VERSION_NUMBER < 0x10100000L || \
  	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)

  	ret = SSL_library_init();

  #else
  	ret = OPENSSL_init_ssl(0, NULL);
  #endif

  	if (!ret) {
  		fprintf(stderr, "Failure to init SSL library
  ");
  		return -1;
  	}

  #if OPENSSL_VERSION_NUMBER < 0x10100000L || \
  	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)

  	SSL_load_error_strings();
  
  	OpenSSL_add_all_algorithms();
  	OpenSSL_add_all_digests();
  	OpenSSL_add_all_ciphers();

  #endif

  
  	return 0;
  }

  static int rsa_engine_init(const char *engine_id, ENGINE **pe)
  {
  	ENGINE *e;
  	int ret;
  
  	ENGINE_load_builtin_engines();
  
  	e = ENGINE_by_id(engine_id);
  	if (!e) {
  		fprintf(stderr, "Engine isn't available
  ");
  		ret = -1;
  		goto err_engine_by_id;
  	}
  
  	if (!ENGINE_init(e)) {
  		fprintf(stderr, "Couldn't initialize engine
  ");
  		ret = -1;
  		goto err_engine_init;
  	}
  
  	if (!ENGINE_set_default_RSA(e)) {
  		fprintf(stderr, "Couldn't set engine as default for RSA
  ");
  		ret = -1;
  		goto err_set_rsa;
  	}
  
  	*pe = e;
  
  	return 0;
  
  err_set_rsa:
  	ENGINE_finish(e);
  err_engine_init:
  	ENGINE_free(e);
  err_engine_by_id:

  #if OPENSSL_VERSION_NUMBER < 0x10100000L || \
  	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)

  	ENGINE_cleanup();

  #endif

  	return ret;
  }

  static void rsa_remove(void)
  {

  #if OPENSSL_VERSION_NUMBER < 0x10100000L || \
  	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)

  	CRYPTO_cleanup_all_ex_data();
  	ERR_free_strings();
  #ifdef HAVE_ERR_REMOVE_THREAD_STATE
  	ERR_remove_thread_state(NULL);
  #else
  	ERR_remove_state(0);
  #endif
  	EVP_cleanup();

  #endif

  }

  static void rsa_engine_remove(ENGINE *e)
  {
  	if (e) {
  		ENGINE_finish(e);
  		ENGINE_free(e);
  	}
  }

  static int rsa_sign_with_key(RSA *rsa, struct padding_algo *padding_algo,
  			     struct checksum_algo *checksum_algo,

  		const struct image_region region[], int region_count,
  		uint8_t **sigp, uint *sig_size)

  {
  	EVP_PKEY *key;

  	EVP_PKEY_CTX *ckey;

  	EVP_MD_CTX *context;

  	int ret = 0;
  	size_t size;

  	uint8_t *sig;
  	int i;
  
  	key = EVP_PKEY_new();
  	if (!key)
  		return rsa_err("EVP_PKEY object creation failed");
  
  	if (!EVP_PKEY_set1_RSA(key, rsa)) {
  		ret = rsa_err("EVP key setup failed");
  		goto err_set;
  	}
  
  	size = EVP_PKEY_size(key);
  	sig = malloc(size);
  	if (!sig) {

  		fprintf(stderr, "Out of memory for signature (%zu bytes)
  ",

  			size);
  		ret = -ENOMEM;
  		goto err_alloc;
  	}
  
  	context = EVP_MD_CTX_create();
  	if (!context) {
  		ret = rsa_err("EVP context creation failed");
  		goto err_create;
  	}
  	EVP_MD_CTX_init(context);

  
  	ckey = EVP_PKEY_CTX_new(key, NULL);
  	if (!ckey) {
  		ret = rsa_err("EVP key context creation failed");
  		goto err_create;
  	}
  
  	if (EVP_DigestSignInit(context, &ckey,

  			       checksum_algo->calculate_sign(),
  			       NULL, key) <= 0) {

  		ret = rsa_err("Signer setup failed");
  		goto err_sign;
  	}

  #ifdef CONFIG_FIT_ENABLE_RSASSA_PSS_SUPPORT
  	if (padding_algo && !strcmp(padding_algo->name, "pss")) {
  		if (EVP_PKEY_CTX_set_rsa_padding(ckey,
  						 RSA_PKCS1_PSS_PADDING) <= 0) {
  			ret = rsa_err("Signer padding setup failed");
  			goto err_sign;
  		}
  	}
  #endif /* CONFIG_FIT_ENABLE_RSASSA_PSS_SUPPORT */

  	for (i = 0; i < region_count; i++) {

  		if (!EVP_DigestSignUpdate(context, region[i].data,
  					  region[i].size)) {

  			ret = rsa_err("Signing data failed");
  			goto err_sign;
  		}
  	}

  	if (!EVP_DigestSignFinal(context, sig, &size)) {

  		ret = rsa_err("Could not obtain signature");
  		goto err_sign;
  	}

  	#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
  		(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)

  		EVP_MD_CTX_cleanup(context);
  	#else
  		EVP_MD_CTX_reset(context);
  	#endif

  	EVP_MD_CTX_destroy(context);
  	EVP_PKEY_free(key);

  	debug("Got signature: %d bytes, expected %zu
  ", *sig_size, size);

  	*sigp = sig;
  	*sig_size = size;
  
  	return 0;
  
  err_sign:
  	EVP_MD_CTX_destroy(context);
  err_create:
  	free(sig);
  err_alloc:
  err_set:
  	EVP_PKEY_free(key);
  	return ret;
  }
  
  int rsa_sign(struct image_sign_info *info,
  	     const struct image_region region[], int region_count,
  	     uint8_t **sigp, uint *sig_len)
  {
  	RSA *rsa;

  	ENGINE *e = NULL;

  	int ret;
  
  	ret = rsa_init();
  	if (ret)
  		return ret;

  	if (info->engine_id) {
  		ret = rsa_engine_init(info->engine_id, &e);
  		if (ret)
  			goto err_engine;
  	}
  
  	ret = rsa_get_priv_key(info->keydir, info->keyname, e, &rsa);

  	if (ret)
  		goto err_priv;

  	ret = rsa_sign_with_key(rsa, info->padding, info->checksum, region,

  				region_count, sigp, sig_len);

  	if (ret)
  		goto err_sign;
  
  	RSA_free(rsa);

  	if (info->engine_id)
  		rsa_engine_remove(e);

  	rsa_remove();
  
  	return ret;
  
  err_sign:
  	RSA_free(rsa);
  err_priv:

  	if (info->engine_id)
  		rsa_engine_remove(e);
  err_engine:

  	rsa_remove();
  	return ret;
  }
  
  /*

   * rsa_get_exponent(): - Get the public exponent from an RSA key
   */
  static int rsa_get_exponent(RSA *key, uint64_t *e)
  {
  	int ret;
  	BIGNUM *bn_te;

  	const BIGNUM *key_e;

  	uint64_t te;
  
  	ret = -EINVAL;
  	bn_te = NULL;
  
  	if (!e)
  		goto cleanup;

  	RSA_get0_key(key, NULL, &key_e, NULL);
  	if (BN_num_bits(key_e) > 64)

  		goto cleanup;

  	*e = BN_get_word(key_e);

  	if (BN_num_bits(key_e) < 33) {

  		ret = 0;
  		goto cleanup;
  	}

  	bn_te = BN_dup(key_e);

  	if (!bn_te)
  		goto cleanup;
  
  	if (!BN_rshift(bn_te, bn_te, 32))
  		goto cleanup;
  
  	if (!BN_mask_bits(bn_te, 32))
  		goto cleanup;
  
  	te = BN_get_word(bn_te);
  	te <<= 32;
  	*e |= te;
  	ret = 0;
  
  cleanup:
  	if (bn_te)
  		BN_free(bn_te);
  
  	return ret;
  }
  
  /*

   * rsa_get_params(): - Get the important parameters of an RSA public key
   */

  int rsa_get_params(RSA *key, uint64_t *exponent, uint32_t *n0_invp,
  		   BIGNUM **modulusp, BIGNUM **r_squaredp)

  {
  	BIGNUM *big1, *big2, *big32, *big2_32;
  	BIGNUM *n, *r, *r_squared, *tmp;

  	const BIGNUM *key_n;

  	BN_CTX *bn_ctx = BN_CTX_new();
  	int ret = 0;
  
  	/* Initialize BIGNUMs */
  	big1 = BN_new();
  	big2 = BN_new();
  	big32 = BN_new();
  	r = BN_new();
  	r_squared = BN_new();
  	tmp = BN_new();
  	big2_32 = BN_new();
  	n = BN_new();
  	if (!big1 || !big2 || !big32 || !r || !r_squared || !tmp || !big2_32 ||
  	    !n) {
  		fprintf(stderr, "Out of memory (bignum)
  ");
  		return -ENOMEM;
  	}

  	if (0 != rsa_get_exponent(key, exponent))
  		ret = -1;

  	RSA_get0_key(key, &key_n, NULL, NULL);
  	if (!BN_copy(n, key_n) || !BN_set_word(big1, 1L) ||

  	    !BN_set_word(big2, 2L) || !BN_set_word(big32, 32L))
  		ret = -1;
  
  	/* big2_32 = 2^32 */
  	if (!BN_exp(big2_32, big2, big32, bn_ctx))
  		ret = -1;
  
  	/* Calculate n0_inv = -1 / n[0] mod 2^32 */
  	if (!BN_mod_inverse(tmp, n, big2_32, bn_ctx) ||
  	    !BN_sub(tmp, big2_32, tmp))
  		ret = -1;
  	*n0_invp = BN_get_word(tmp);
  
  	/* Calculate R = 2^(# of key bits) */
  	if (!BN_set_word(tmp, BN_num_bits(n)) ||
  	    !BN_exp(r, big2, tmp, bn_ctx))
  		ret = -1;
  
  	/* Calculate r_squared = R^2 mod n */
  	if (!BN_copy(r_squared, r) ||
  	    !BN_mul(tmp, r_squared, r, bn_ctx) ||
  	    !BN_mod(r_squared, tmp, n, bn_ctx))
  		ret = -1;
  
  	*modulusp = n;
  	*r_squaredp = r_squared;
  
  	BN_free(big1);
  	BN_free(big2);
  	BN_free(big32);
  	BN_free(r);
  	BN_free(tmp);
  	BN_free(big2_32);
  	if (ret) {
  		fprintf(stderr, "Bignum operations failed
  ");
  		return -ENOMEM;
  	}
  
  	return ret;
  }
  
  static int fdt_add_bignum(void *blob, int noffset, const char *prop_name,
  			  BIGNUM *num, int num_bits)
  {
  	int nwords = num_bits / 32;
  	int size;
  	uint32_t *buf, *ptr;
  	BIGNUM *tmp, *big2, *big32, *big2_32;
  	BN_CTX *ctx;
  	int ret;
  
  	tmp = BN_new();
  	big2 = BN_new();
  	big32 = BN_new();
  	big2_32 = BN_new();

  
  	/*
  	 * Note: This code assumes that all of the above succeed, or all fail.
  	 * In practice memory allocations generally do not fail (unless the
  	 * process is killed), so it does not seem worth handling each of these
  	 * as a separate case. Technicaly this could leak memory on failure,
  	 * but a) it won't happen in practice, and b) it doesn't matter as we
  	 * will immediately exit with a failure code.
  	 */

  	if (!tmp || !big2 || !big32 || !big2_32) {
  		fprintf(stderr, "Out of memory (bignum)
  ");
  		return -ENOMEM;
  	}
  	ctx = BN_CTX_new();
  	if (!tmp) {
  		fprintf(stderr, "Out of memory (bignum context)
  ");
  		return -ENOMEM;
  	}
  	BN_set_word(big2, 2L);
  	BN_set_word(big32, 32L);
  	BN_exp(big2_32, big2, big32, ctx); /* B = 2^32 */
  
  	size = nwords * sizeof(uint32_t);
  	buf = malloc(size);
  	if (!buf) {
  		fprintf(stderr, "Out of memory (%d bytes)
  ", size);
  		return -ENOMEM;
  	}
  
  	/* Write out modulus as big endian array of integers */
  	for (ptr = buf + nwords - 1; ptr >= buf; ptr--) {
  		BN_mod(tmp, num, big2_32, ctx); /* n = N mod B */
  		*ptr = cpu_to_fdt32(BN_get_word(tmp));
  		BN_rshift(num, num, 32); /*  N = N/B */
  	}

  	/*
  	 * We try signing with successively increasing size values, so this
  	 * might fail several times
  	 */

  	ret = fdt_setprop(blob, noffset, prop_name, buf, size);

  	free(buf);
  	BN_free(tmp);
  	BN_free(big2);
  	BN_free(big32);
  	BN_free(big2_32);

  	return ret ? -FDT_ERR_NOSPACE : 0;

  }
  
  int rsa_add_verify_data(struct image_sign_info *info, void *keydest)
  {
  	BIGNUM *modulus, *r_squared;

  	uint64_t exponent;

  	uint32_t n0_inv;
  	int parent, node;
  	char name[100];
  	int ret;
  	int bits;
  	RSA *rsa;

  	ENGINE *e = NULL;

  
  	debug("%s: Getting verification data
  ", __func__);

  	if (info->engine_id) {
  		ret = rsa_engine_init(info->engine_id, &e);
  		if (ret)
  			return ret;
  	}
  	ret = rsa_get_pub_key(info->keydir, info->keyname, e, &rsa);

  	if (ret)

  		goto err_get_pub_key;

  	ret = rsa_get_params(rsa, &exponent, &n0_inv, &modulus, &r_squared);

  	if (ret)

  		goto err_get_params;

  	bits = BN_num_bits(modulus);
  	parent = fdt_subnode_offset(keydest, 0, FIT_SIG_NODENAME);
  	if (parent == -FDT_ERR_NOTFOUND) {
  		parent = fdt_add_subnode(keydest, 0, FIT_SIG_NODENAME);
  		if (parent < 0) {

  			ret = parent;
  			if (ret != -FDT_ERR_NOSPACE) {
  				fprintf(stderr, "Couldn't create signature node: %s
  ",
  					fdt_strerror(parent));
  			}

  		}
  	}

  	if (ret)
  		goto done;

  
  	/* Either create or overwrite the named key node */
  	snprintf(name, sizeof(name), "key-%s", info->keyname);
  	node = fdt_subnode_offset(keydest, parent, name);
  	if (node == -FDT_ERR_NOTFOUND) {
  		node = fdt_add_subnode(keydest, parent, name);
  		if (node < 0) {

  			ret = node;
  			if (ret != -FDT_ERR_NOSPACE) {
  				fprintf(stderr, "Could not create key subnode: %s
  ",
  					fdt_strerror(node));
  			}

  		}
  	} else if (node < 0) {
  		fprintf(stderr, "Cannot select keys parent: %s
  ",
  			fdt_strerror(node));

  		ret = node;

  	}

  	if (!ret) {
  		ret = fdt_setprop_string(keydest, node, "key-name-hint",

  				 info->keyname);

  	}

  	if (!ret)
  		ret = fdt_setprop_u32(keydest, node, "rsa,num-bits", bits);
  	if (!ret)
  		ret = fdt_setprop_u32(keydest, node, "rsa,n0-inverse", n0_inv);
  	if (!ret) {

  		ret = fdt_setprop_u64(keydest, node, "rsa,exponent", exponent);
  	}
  	if (!ret) {

  		ret = fdt_add_bignum(keydest, node, "rsa,modulus", modulus,
  				     bits);
  	}
  	if (!ret) {
  		ret = fdt_add_bignum(keydest, node, "rsa,r-squared", r_squared,
  				     bits);
  	}
  	if (!ret) {
  		ret = fdt_setprop_string(keydest, node, FIT_ALGO_PROP,

  					 info->name);

  	}

  	if (!ret && info->require_keys) {

  		ret = fdt_setprop_string(keydest, node, "required",
  					 info->require_keys);

  	}

  done:

  	BN_free(modulus);
  	BN_free(r_squared);
  	if (ret)

  		ret = ret == -FDT_ERR_NOSPACE ? -ENOSPC : -EIO;
  err_get_params:
  	RSA_free(rsa);
  err_get_pub_key:
  	if (info->engine_id)
  		rsa_engine_remove(e);

  	return ret;

  }