/*

 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/asn1t.h>

#include <openssl/x509.h>

#include "crypto/asn1.h"

#include "crypto/evp.h"

#include "crypto/x509.h"

#include <openssl/rsa.h>

#include <openssl/dsa.h>

struct X509_pubkey_st {

    X509_ALGOR *algor;

    ASN1_BIT_STRING *public_key;

    EVP_PKEY *pkey;

};

static int x509_pubkey_decode(EVP_PKEY **pk, X509_PUBKEY *key);

/* Minor tweak to operation: free up EVP_PKEY */

static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,

                     void *exarg)

{

    if (operation == ASN1_OP_FREE_POST) {

        X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;

        EVP_PKEY_free(pubkey->pkey);

    } else if (operation == ASN1_OP_D2I_POST) {

        /* Attempt to decode public key and cache in pubkey structure. */

        X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;

        EVP_PKEY_free(pubkey->pkey);

        pubkey->pkey = NULL;

        /*

         * Opportunistically decode the key but remove any non fatal errors

         * from the queue. Subsequent explicit attempts to decode/use the key

         * will return an appropriate error.

         */

        ERR_set_mark();

        if (x509_pubkey_decode(&pubkey->pkey, pubkey) == -1)

            return 0;

        ERR_pop_to_mark();

    }

    return 1;

}

ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {

        ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),

        ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING)

} ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)

IMPLEMENT_ASN1_FUNCTIONS(X509_PUBKEY)

int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)

{

    X509_PUBKEY *pk = NULL;

    if (x == NULL)

        return 0;

    if ((pk = X509_PUBKEY_new()) == NULL)

        goto error;

    if (pkey->ameth) {

        if (pkey->ameth->pub_encode) {

            if (!pkey->ameth->pub_encode(pk, pkey)) {

                X509err(X509_F_X509_PUBKEY_SET,

                        X509_R_PUBLIC_KEY_ENCODE_ERROR);

                goto error;

            }

        } else {

            X509err(X509_F_X509_PUBKEY_SET, X509_R_METHOD_NOT_SUPPORTED);

            goto error;

        }

    } else {

        X509err(X509_F_X509_PUBKEY_SET, X509_R_UNSUPPORTED_ALGORITHM);

        goto error;

    }

    X509_PUBKEY_free(*x);

    *x = pk;

    pk->pkey = pkey;

    EVP_PKEY_up_ref(pkey);

    return 1;

 error:

    X509_PUBKEY_free(pk);

    return 0;

}

/*

 * Attempt to decode a public key.

 * Returns 1 on success, 0 for a decode failure and -1 for a fatal

 * error e.g. malloc failure.

 */

static int x509_pubkey_decode(EVP_PKEY **ppkey, X509_PUBKEY *key)

{

    EVP_PKEY *pkey = EVP_PKEY_new();

    if (pkey == NULL) {

        X509err(X509_F_X509_PUBKEY_DECODE, ERR_R_MALLOC_FAILURE);

        return -1;

    }

    if (!EVP_PKEY_set_type(pkey, OBJ_obj2nid(key->algor->algorithm))) {

        X509err(X509_F_X509_PUBKEY_DECODE, X509_R_UNSUPPORTED_ALGORITHM);

        goto error;

    }

    if (pkey->ameth->pub_decode) {

        /*

         * Treat any failure of pub_decode as a decode error. In

         * future we could have different return codes for decode

         * errors and fatal errors such as malloc failure.

         */

        if (!pkey->ameth->pub_decode(pkey, key)) {

            X509err(X509_F_X509_PUBKEY_DECODE, X509_R_PUBLIC_KEY_DECODE_ERROR);

            goto error;

        }

    } else {

        X509err(X509_F_X509_PUBKEY_DECODE, X509_R_METHOD_NOT_SUPPORTED);

        goto error;

    }

    *ppkey = pkey;

    return 1;

 error:

    EVP_PKEY_free(pkey);

    return 0;

}

EVP_PKEY *X509_PUBKEY_get0(X509_PUBKEY *key)

{

    EVP_PKEY *ret = NULL;

    if (key == NULL || key->public_key == NULL)

        return NULL;

    if (key->pkey != NULL)

        return key->pkey;

    /*

     * When the key ASN.1 is initially parsed an attempt is made to

     * decode the public key and cache the EVP_PKEY structure. If this

     * operation fails the cached value will be NULL. Parsing continues

     * to allow parsing of unknown key types or unsupported forms.

     * We repeat the decode operation so the appropriate errors are left

     * in the queue.

     */

    x509_pubkey_decode(&ret, key);

    /* If decode doesn't fail something bad happened */

    if (ret != NULL) {

        X509err(X509_F_X509_PUBKEY_GET0, ERR_R_INTERNAL_ERROR);

        EVP_PKEY_free(ret);

    }

    return NULL;

}

EVP_PKEY *X509_PUBKEY_get(X509_PUBKEY *key)

{

    EVP_PKEY *ret = X509_PUBKEY_get0(key);

    if (ret != NULL && !EVP_PKEY_up_ref(ret)) {

        X509err(X509_F_X509_PUBKEY_GET, ERR_R_INTERNAL_ERROR);

        ret = NULL;

    }

    return ret;

}

/*

 * Now two pseudo ASN1 routines that take an EVP_PKEY structure and encode or

 * decode as X509_PUBKEY

 */

EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)

{

    X509_PUBKEY *xpk;

    EVP_PKEY *pktmp;

    const unsigned char *q;

    q = *pp;

    xpk = d2i_X509_PUBKEY(NULL, &q, length);

    if (!xpk)

        return NULL;

    pktmp = X509_PUBKEY_get(xpk);

    X509_PUBKEY_free(xpk);

    if (!pktmp)

        return NULL;

    *pp = q;

    if (a) {

        EVP_PKEY_free(*a);

        *a = pktmp;

    }

    return pktmp;

}

int i2d_PUBKEY(EVP_PKEY *a, unsigned char **pp)

{

    X509_PUBKEY *xpk = NULL;

    int ret;

    if (!a)

        return 0;

    if (!X509_PUBKEY_set(&xpk, a))

        return -1;

    ret = i2d_X509_PUBKEY(xpk, pp);

    X509_PUBKEY_free(xpk);

    return ret;

}

/*

 * The following are equivalents but which return RSA and DSA keys

 */

#ifndef OPENSSL_NO_RSA

RSA *d2i_RSA_PUBKEY(RSA **a, const unsigned char **pp, long length)

{

    EVP_PKEY *pkey;

    RSA *key;

    const unsigned char *q;

    q = *pp;

    pkey = d2i_PUBKEY(NULL, &q, length);

    if (!pkey)

        return NULL;

    key = EVP_PKEY_get1_RSA(pkey);

    EVP_PKEY_free(pkey);

    if (!key)

        return NULL;

    *pp = q;

    if (a) {

        RSA_free(*a);

        *a = key;

    }

    return key;

}

int i2d_RSA_PUBKEY(RSA *a, unsigned char **pp)

{

    EVP_PKEY *pktmp;

    int ret;

    if (!a)

        return 0;

    pktmp = EVP_PKEY_new();

    if (pktmp == NULL) {

        ASN1err(ASN1_F_I2D_RSA_PUBKEY, ERR_R_MALLOC_FAILURE);

        return -1;

    }

    EVP_PKEY_set1_RSA(pktmp, a);

    ret = i2d_PUBKEY(pktmp, pp);

    EVP_PKEY_free(pktmp);

    return ret;

}

#endif

#ifndef OPENSSL_NO_DSA

DSA *d2i_DSA_PUBKEY(DSA **a, const unsigned char **pp, long length)

{

    EVP_PKEY *pkey;

    DSA *key;

    const unsigned char *q;

    q = *pp;

    pkey = d2i_PUBKEY(NULL, &q, length);

    if (!pkey)

        return NULL;

    key = EVP_PKEY_get1_DSA(pkey);

    EVP_PKEY_free(pkey);

    if (!key)

        return NULL;

    *pp = q;

    if (a) {

        DSA_free(*a);

        *a = key;

    }

    return key;

}

int i2d_DSA_PUBKEY(DSA *a, unsigned char **pp)

{

    EVP_PKEY *pktmp;

    int ret;

    if (!a)

        return 0;

    pktmp = EVP_PKEY_new();

    if (pktmp == NULL) {

        ASN1err(ASN1_F_I2D_DSA_PUBKEY, ERR_R_MALLOC_FAILURE);

        return -1;

    }

    EVP_PKEY_set1_DSA(pktmp, a);

    ret = i2d_PUBKEY(pktmp, pp);

    EVP_PKEY_free(pktmp);

    return ret;

}

#endif

#ifndef OPENSSL_NO_EC

EC_KEY *d2i_EC_PUBKEY(EC_KEY **a, const unsigned char **pp, long length)

{

    EVP_PKEY *pkey;

    EC_KEY *key;

    const unsigned char *q;

    q = *pp;

    pkey = d2i_PUBKEY(NULL, &q, length);

    if (!pkey)

        return NULL;

    key = EVP_PKEY_get1_EC_KEY(pkey);

    EVP_PKEY_free(pkey);

    if (!key)

        return NULL;

    *pp = q;

    if (a) {

        EC_KEY_free(*a);

        *a = key;

    }

    return key;

}

int i2d_EC_PUBKEY(EC_KEY *a, unsigned char **pp)

{

    EVP_PKEY *pktmp;

    int ret;

    if (!a)

        return 0;

    if ((pktmp = EVP_PKEY_new()) == NULL) {

        ASN1err(ASN1_F_I2D_EC_PUBKEY, ERR_R_MALLOC_FAILURE);

        return -1;

    }

    EVP_PKEY_set1_EC_KEY(pktmp, a);

    ret = i2d_PUBKEY(pktmp, pp);

    EVP_PKEY_free(pktmp);

    return ret;

}

#endif

int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,

                           int ptype, void *pval,

                           unsigned char *penc, int penclen)

{

    if (!X509_ALGOR_set0(pub->algor, aobj, ptype, pval))

        return 0;

    if (penc) {

        OPENSSL_free(pub->public_key->data);

        pub->public_key->data = penc;

        pub->public_key->length = penclen;

        /* Set number of unused bits to zero */

        pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);

        pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;

    }

    return 1;

}

int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,

                           const unsigned char **pk, int *ppklen,

                           X509_ALGOR **pa, X509_PUBKEY *pub)

{

    if (ppkalg)

        *ppkalg = pub->algor->algorithm;

    if (pk) {

        *pk = pub->public_key->data;

        *ppklen = pub->public_key->length;

    }

    if (pa)

        *pa = pub->algor;

    return 1;

}

ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x)

{

    if (x == NULL)

        return NULL;

    return x->cert_info.key->public_key;

}