// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * RSA key extract helper
 *
 * Copyright (c) 2015, Intel Corporation
 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/fips.h>
#include <crypto/internal/rsa.h>
#include "rsapubkey.asn1.h"
#include "rsaprivkey.asn1.h"

int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
              const void *value, size_t vlen)
{
        struct rsa_key *key = context;
        const u8 *ptr = value;
        size_t n_sz = vlen;

        /* invalid key provided */
        if (!value || !vlen)
                return -EINVAL;

        if (fips_enabled) {
                while (n_sz && !*ptr) {
                        ptr++;
                        n_sz--;
                }

                /* In FIPS mode only allow key size 2K and higher */
                if (n_sz < 256) {
                        pr_err("RSA: key size not allowed in FIPS mode\n");
                        return -EINVAL;
                }
        }

        key->n = value;
        key->n_sz = vlen;

        return 0;
}

int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
              const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->e = value;
        key->e_sz = vlen;

        return 0;
}

int rsa_get_d(void *context, size_t hdrlen, unsigned char tag,
              const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->d = value;
        key->d_sz = vlen;

        return 0;
}

int rsa_get_p(void *context, size_t hdrlen, unsigned char tag,
              const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->p = value;
        key->p_sz = vlen;

        return 0;
}

int rsa_get_q(void *context, size_t hdrlen, unsigned char tag,
              const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->q = value;
        key->q_sz = vlen;

        return 0;
}

int rsa_get_dp(void *context, size_t hdrlen, unsigned char tag,
               const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->dp = value;
        key->dp_sz = vlen;

        return 0;
}

int rsa_get_dq(void *context, size_t hdrlen, unsigned char tag,
               const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->dq = value;
        key->dq_sz = vlen;

        return 0;
}

int rsa_get_qinv(void *context, size_t hdrlen, unsigned char tag,
                 const void *value, size_t vlen)
{
        struct rsa_key *key = context;

        /* invalid key provided */
        if (!value || !vlen || vlen > key->n_sz)
                return -EINVAL;

        key->qinv = value;
        key->qinv_sz = vlen;

        return 0;
}

/**
 * rsa_parse_pub_key() - decodes the BER encoded buffer and stores in the
 *                       provided struct rsa_key, pointers to the raw key as is,
 *                       so that the caller can copy it or MPI parse it, etc.
 *
 * @rsa_key:    struct rsa_key key representation
 * @key:        key in BER format
 * @key_len:    length of key
 *
 * Return:      0 on success or error code in case of error
 */
int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key,
                      unsigned int key_len)
{
        return asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len);
}
EXPORT_SYMBOL_GPL(rsa_parse_pub_key);

/**
 * rsa_parse_priv_key() - decodes the BER encoded buffer and stores in the
 *                        provided struct rsa_key, pointers to the raw key
 *                        as is, so that the caller can copy it or MPI parse it,
 *                        etc.
 *
 * @rsa_key:    struct rsa_key key representation
 * @key:        key in BER format
 * @key_len:    length of key
 *
 * Return:      0 on success or error code in case of error
 */
int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key,
                       unsigned int key_len)
{
        return asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len);
}
EXPORT_SYMBOL_GPL(rsa_parse_priv_key);