/*

 * Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (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/bn.h>

#include <openssl/evp.h>

#include <openssl/objects.h>

#include <openssl/decoder.h>

#include <openssl/x509.h>

#include <openssl/asn1.h>

#include "crypto/asn1.h"

#include "crypto/evp.h"

#include "crypto/x509.h"

#include "internal/asn1.h"

#include "internal/sizes.h"

static EVP_PKEY *

d2i_PrivateKey_decoder(int keytype, EVP_PKEY **a, const unsigned char **pp,

    long length, OSSL_LIB_CTX *libctx, const char *propq)

{

    OSSL_DECODER_CTX *dctx = NULL;

    size_t len = length;

    EVP_PKEY *pkey = NULL, *bak_a = NULL;

    EVP_PKEY **ppkey = &pkey;

    const char *key_name = NULL;

    char keytypebuf[OSSL_MAX_NAME_SIZE];

    int ret;

    const unsigned char *p = *pp;

    const char *structure;

    PKCS8_PRIV_KEY_INFO *p8info;

    const ASN1_OBJECT *algoid;

    if (keytype != EVP_PKEY_NONE) {

        key_name = evp_pkey_type2name(keytype);

        if (key_name == NULL)

            return NULL;

    }

    /* This is just a probe. It might fail, so we ignore errors */

    ERR_set_mark();

    p8info = d2i_PKCS8_PRIV_KEY_INFO(NULL, pp, length);

    ERR_pop_to_mark();

    if (p8info != NULL) {

        int64_t v;

        /* ascertain version is 0 or 1 as per RFC5958 */

        if (!ASN1_INTEGER_get_int64(&v, p8info->version)

            || (v != 0 && v != 1)) {

            *pp = p;

            ERR_raise(ERR_LIB_ASN1, ASN1_R_ASN1_PARSE_ERROR);

            PKCS8_PRIV_KEY_INFO_free(p8info);

            return NULL;

        }

        if (key_name == NULL

            && PKCS8_pkey_get0(&algoid, NULL, NULL, NULL, p8info)

            && OBJ_obj2txt(keytypebuf, sizeof(keytypebuf), algoid, 0))

            key_name = keytypebuf;

        structure = "PrivateKeyInfo";

        PKCS8_PRIV_KEY_INFO_free(p8info);

    } else {

        structure = "type-specific";

    }

    *pp = p;

    if (a != NULL && (bak_a = *a) != NULL)

        ppkey = a;

    dctx = OSSL_DECODER_CTX_new_for_pkey(ppkey, "DER", structure, key_name,

        EVP_PKEY_KEYPAIR, libctx, propq);

    if (a != NULL)

        *a = bak_a;

    if (dctx == NULL)

        goto err;

    ret = OSSL_DECODER_from_data(dctx, pp, &len);

    OSSL_DECODER_CTX_free(dctx);

    if (ret

        && *ppkey != NULL

        && evp_keymgmt_util_has(*ppkey, OSSL_KEYMGMT_SELECT_PRIVATE_KEY)) {

        if (a != NULL)

            *a = *ppkey;

        return *ppkey;

    }

err:

    if (ppkey != a)

        EVP_PKEY_free(*ppkey);

    return NULL;

}

EVP_PKEY *

ossl_d2i_PrivateKey_legacy(int keytype, EVP_PKEY **a, const unsigned char **pp,

    long length, OSSL_LIB_CTX *libctx, const char *propq)

{

    EVP_PKEY *ret;

    const unsigned char *p = *pp;

    if (a == NULL || *a == NULL) {

        if ((ret = EVP_PKEY_new()) == NULL) {

            ERR_raise(ERR_LIB_ASN1, ERR_R_EVP_LIB);

            return NULL;

        }

    } else {

        ret = *a;

    }

    if (!EVP_PKEY_set_type(ret, keytype)) {

        ERR_raise(ERR_LIB_ASN1, ASN1_R_UNKNOWN_PUBLIC_KEY_TYPE);

        goto err;

    }

    ERR_set_mark();

    if (!ret->ameth->old_priv_decode || !ret->ameth->old_priv_decode(ret, &p, length)) {

        if (ret->ameth->priv_decode != NULL

            || ret->ameth->priv_decode_ex != NULL) {

            EVP_PKEY *tmp;

            PKCS8_PRIV_KEY_INFO *p8 = NULL;

            p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, length);

            if (p8 == NULL) {

                ERR_clear_last_mark();

                goto err;

            }

            tmp = evp_pkcs82pkey_legacy(p8, libctx, propq);

            PKCS8_PRIV_KEY_INFO_free(p8);

            if (tmp == NULL) {

                ERR_clear_last_mark();

                goto err;

            }

            EVP_PKEY_free(ret);

            ret = tmp;

            ERR_pop_to_mark();

            if (EVP_PKEY_type(keytype) != EVP_PKEY_get_base_id(ret))

                goto err;

        } else {

            ERR_clear_last_mark();

            ERR_raise(ERR_LIB_ASN1, ERR_R_ASN1_LIB);

            goto err;

        }

    } else {

        ERR_clear_last_mark();

    }

    *pp = p;

    if (a != NULL)

        *a = ret;

    return ret;

err:

    if (a == NULL || *a != ret)

        EVP_PKEY_free(ret);

    return NULL;

}

EVP_PKEY *d2i_PrivateKey_ex(int keytype, EVP_PKEY **a, const unsigned char **pp,

    long length, OSSL_LIB_CTX *libctx,

    const char *propq)

{

    EVP_PKEY *ret;

    ret = d2i_PrivateKey_decoder(keytype, a, pp, length, libctx, propq);

    /* try the legacy path if the decoder failed */

    if (ret == NULL)

        ret = ossl_d2i_PrivateKey_legacy(keytype, a, pp, length, libctx, propq);

    return ret;

}

EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **a, const unsigned char **pp,

    long length)

{

    return d2i_PrivateKey_ex(type, a, pp, length, NULL, NULL);

}

static EVP_PKEY *d2i_AutoPrivateKey_legacy(EVP_PKEY **a,

    const unsigned char **pp,

    long length,

    OSSL_LIB_CTX *libctx,

    const char *propq)

{

    STACK_OF(ASN1_TYPE) *inkey;

    const unsigned char *p;

    int keytype;

    p = *pp;

    /*

     * Dirty trick: read in the ASN1 data into a STACK_OF(ASN1_TYPE): by

     * analyzing it we can determine the passed structure: this assumes the

     * input is surrounded by an ASN1 SEQUENCE.

     */

    inkey = d2i_ASN1_SEQUENCE_ANY(NULL, &p, length);

    p = *pp;

    /*

     * Since we only need to discern "traditional format" RSA and DSA keys we

     * can just count the elements.

     */

    if (sk_ASN1_TYPE_num(inkey) == 6) {

        keytype = EVP_PKEY_DSA;

    } else if (sk_ASN1_TYPE_num(inkey) == 4) {

        keytype = EVP_PKEY_EC;

    } else if (sk_ASN1_TYPE_num(inkey) == 3) { /* This seems to be PKCS8, not

                                                * traditional format */

        PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, length);

        EVP_PKEY *ret;

        sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);

        if (p8 == NULL) {

            ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_PUBLIC_KEY_TYPE);

            return NULL;

        }

        ret = evp_pkcs82pkey_legacy(p8, libctx, propq);

        PKCS8_PRIV_KEY_INFO_free(p8);

        if (ret == NULL)

            return NULL;

        *pp = p;

        if (a != NULL) {

            *a = ret;

        }

        return ret;

    } else {

        keytype = EVP_PKEY_RSA;

    }

    sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);

    return ossl_d2i_PrivateKey_legacy(keytype, a, pp, length, libctx, propq);

}

/*

 * This works like d2i_PrivateKey() except it passes the keytype as

 * EVP_PKEY_NONE, which then figures out the type during decoding.

 */

EVP_PKEY *d2i_AutoPrivateKey_ex(EVP_PKEY **a, const unsigned char **pp,

    long length, OSSL_LIB_CTX *libctx,

    const char *propq)

{

    EVP_PKEY *ret;

    ret = d2i_PrivateKey_decoder(EVP_PKEY_NONE, a, pp, length, libctx, propq);

    /* try the legacy path if the decoder failed */

    if (ret == NULL)

        ret = d2i_AutoPrivateKey_legacy(a, pp, length, libctx, propq);

    return ret;

}

EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp,

    long length)

{

    return d2i_AutoPrivateKey_ex(a, pp, length, NULL, NULL);

}