/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * RSA internal helpers
 *
 * Copyright (c) 2015, Intel Corporation
 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
 */
#ifndef _RSA_HELPER_
#define _RSA_HELPER_
#include <linux/types.h>
#include <crypto/akcipher.h>

/**
 * rsa_key - RSA key structure
 * @n           : RSA modulus raw byte stream
 * @e           : RSA public exponent raw byte stream
 * @d           : RSA private exponent raw byte stream
 * @p           : RSA prime factor p of n raw byte stream
 * @q           : RSA prime factor q of n raw byte stream
 * @dp          : RSA exponent d mod (p - 1) raw byte stream
 * @dq          : RSA exponent d mod (q - 1) raw byte stream
 * @qinv        : RSA CRT coefficient q^(-1) mod p raw byte stream
 * @n_sz        : length in bytes of RSA modulus n
 * @e_sz        : length in bytes of RSA public exponent
 * @d_sz        : length in bytes of RSA private exponent
 * @p_sz        : length in bytes of p field
 * @q_sz        : length in bytes of q field
 * @dp_sz       : length in bytes of dp field
 * @dq_sz       : length in bytes of dq field
 * @qinv_sz     : length in bytes of qinv field
 */
struct rsa_key {
        const u8 *n;
        const u8 *e;
        const u8 *d;
        const u8 *p;
        const u8 *q;
        const u8 *dp;
        const u8 *dq;
        const u8 *qinv;
        size_t n_sz;
        size_t e_sz;
        size_t d_sz;
        size_t p_sz;
        size_t q_sz;
        size_t dp_sz;
        size_t dq_sz;
        size_t qinv_sz;
};

int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key,
                      unsigned int key_len);

int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key,
                       unsigned int key_len);

#define RSA_PUB (true)
#define RSA_PRIV (false)

static inline int rsa_set_key(struct crypto_akcipher *child,
                              unsigned int *key_size, bool is_pubkey,
                              const void *key, unsigned int keylen)
{
        int err;

        *key_size = 0;

        if (is_pubkey)
                err = crypto_akcipher_set_pub_key(child, key, keylen);
        else
                err = crypto_akcipher_set_priv_key(child, key, keylen);
        if (err)
                return err;

        /* Find out new modulus size from rsa implementation */
        err = crypto_akcipher_maxsize(child);
        if (err > PAGE_SIZE)
                return -ENOTSUPP;

        *key_size = err;
        return 0;
}

extern struct crypto_template rsa_pkcs1pad_tmpl;
extern struct crypto_template rsassa_pkcs1_tmpl;
#endif