/*

 * Copyright 2020-2022 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

 */

/*

 * low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <string.h>

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/core_object.h>

#include <openssl/crypto.h>

#include <openssl/params.h>

#include <openssl/pem.h>         /* For public PVK functions */

#include <openssl/x509.h>

#include <openssl/err.h>

#include "internal/passphrase.h"

#include "crypto/pem.h"          /* For internal PVK and "blob" headers */

#include "crypto/rsa.h"

#include "prov/bio.h"

#include "prov/implementations.h"

#include "endecoder_local.h"

struct msblob2key_ctx_st;            /* Forward declaration */

typedef void *b2i_of_void_fn(const unsigned char **in, unsigned int bitlen,

                             int ispub);

typedef void adjust_key_fn(void *, struct msblob2key_ctx_st *ctx);

typedef void free_key_fn(void *);

struct keytype_desc_st {

    int type;                 /* EVP key type */

    const char *name;         /* Keytype */

    const OSSL_DISPATCH *fns; /* Keymgmt (to pilfer functions from) */

    b2i_of_void_fn *read_private_key;

    b2i_of_void_fn *read_public_key;

    adjust_key_fn *adjust_key;

    free_key_fn *free_key;

};

static OSSL_FUNC_decoder_freectx_fn msblob2key_freectx;

static OSSL_FUNC_decoder_decode_fn msblob2key_decode;

static OSSL_FUNC_decoder_export_object_fn msblob2key_export_object;

/*

 * Context used for DER to key decoding.

 */

struct msblob2key_ctx_st {

    PROV_CTX *provctx;

    const struct keytype_desc_st *desc;

    /* The selection that is passed to msblob2key_decode() */

    int selection;

};

static struct msblob2key_ctx_st *

msblob2key_newctx(void *provctx, const struct keytype_desc_st *desc)

{

    struct msblob2key_ctx_st *ctx = OPENSSL_zalloc(sizeof(*ctx));

    if (ctx != NULL) {

        ctx->provctx = provctx;

        ctx->desc = desc;

    }

    return ctx;

}

static void msblob2key_freectx(void *vctx)

{

    struct msblob2key_ctx_st *ctx = vctx;

    OPENSSL_free(ctx);

}

static int msblob2key_decode(void *vctx, OSSL_CORE_BIO *cin, int selection,

                             OSSL_CALLBACK *data_cb, void *data_cbarg,

                             OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)

{

    struct msblob2key_ctx_st *ctx = vctx;

    BIO *in = ossl_bio_new_from_core_bio(ctx->provctx, cin);

    const unsigned char *p;

    unsigned char hdr_buf[16], *buf = NULL;

    unsigned int bitlen, magic, length;

    int isdss = -1;

    int ispub = -1;

    void *key = NULL;

    int ok = 0;

    if (in == NULL)

        return 0;

    if (BIO_read(in, hdr_buf, 16) != 16) {

        ERR_raise(ERR_LIB_PEM, PEM_R_KEYBLOB_TOO_SHORT);

        goto next;

    }

    ERR_set_mark();

    p = hdr_buf;

    ok = ossl_do_blob_header(&p, 16, &magic, &bitlen, &isdss, &ispub) > 0;

    ERR_pop_to_mark();

    if (!ok)

        goto next;

    ctx->selection = selection;

    ok = 0;                      /* Assume that we fail */

    if ((isdss && ctx->desc->type != EVP_PKEY_DSA)

        || (!isdss && ctx->desc->type != EVP_PKEY_RSA))

        goto next;

    length = ossl_blob_length(bitlen, isdss, ispub);

    if (length > BLOB_MAX_LENGTH) {

        ERR_raise(ERR_LIB_PEM, PEM_R_HEADER_TOO_LONG);

        goto next;

    }

    buf = OPENSSL_malloc(length);

    if (buf == NULL) {

        ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);

        goto end;

    }

    p = buf;

    if (BIO_read(in, buf, length) != (int)length) {

        ERR_raise(ERR_LIB_PEM, PEM_R_KEYBLOB_TOO_SHORT);

        goto next;

    }

    if ((selection == 0

         || (selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        && !ispub

        && ctx->desc->read_private_key != NULL) {

        struct ossl_passphrase_data_st pwdata;

        memset(&pwdata, 0, sizeof(pwdata));

        if (!ossl_pw_set_ossl_passphrase_cb(&pwdata, pw_cb, pw_cbarg))

            goto end;

        p = buf;

        key = ctx->desc->read_private_key(&p, bitlen, ispub);

        if (selection != 0 && key == NULL)

            goto next;

    }

    if (key == NULL && (selection == 0

         || (selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        && ispub

        && ctx->desc->read_public_key != NULL) {

        p = buf;

        key = ctx->desc->read_public_key(&p, bitlen, ispub);

        if (selection != 0 && key == NULL)

            goto next;

    }

    if (key != NULL && ctx->desc->adjust_key != NULL)

        ctx->desc->adjust_key(key, ctx);

 next:

    /*

     * Indicated that we successfully decoded something, or not at all.

     * Ending up "empty handed" is not an error.

     */

    ok = 1;

    /*

     * We free resources here so it's not held up during the callback, because

     * we know the process is recursive and the allocated chunks of memory

     * add up.

     */

    OPENSSL_free(buf);

    BIO_free(in);

    buf = NULL;

    in = NULL;

    if (key != NULL) {

        OSSL_PARAM params[4];

        int object_type = OSSL_OBJECT_PKEY;

        params[0] =

            OSSL_PARAM_construct_int(OSSL_OBJECT_PARAM_TYPE, &object_type);

        params[1] =

            OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,

                                             (char *)ctx->desc->name, 0);

        /* The address of the key becomes the octet string */

        params[2] =

            OSSL_PARAM_construct_octet_string(OSSL_OBJECT_PARAM_REFERENCE,

                                              &key, sizeof(key));

        params[3] = OSSL_PARAM_construct_end();

        ok = data_cb(params, data_cbarg);

    }

 end:

    BIO_free(in);

    OPENSSL_free(buf);

    ctx->desc->free_key(key);

    return ok;

}

static int

msblob2key_export_object(void *vctx,

                         const void *reference, size_t reference_sz,

                         OSSL_CALLBACK *export_cb, void *export_cbarg)

{

    struct msblob2key_ctx_st *ctx = vctx;

    OSSL_FUNC_keymgmt_export_fn *export =

        ossl_prov_get_keymgmt_export(ctx->desc->fns);

    void *keydata;

    if (reference_sz == sizeof(keydata) && export != NULL) {

        /* The contents of the reference is the address to our object */

        keydata = *(void **)reference;

        return export(keydata, ctx->selection, export_cb, export_cbarg);

    }

    return 0;

}

/* ---------------------------------------------------------------------- */

#define dsa_decode_private_key  (b2i_of_void_fn *)ossl_b2i_DSA_after_header

#define dsa_decode_public_key   (b2i_of_void_fn *)ossl_b2i_DSA_after_header

#define dsa_adjust              NULL

#define dsa_free                (void (*)(void *))DSA_free

/* ---------------------------------------------------------------------- */

#define rsa_decode_private_key  (b2i_of_void_fn *)ossl_b2i_RSA_after_header

#define rsa_decode_public_key   (b2i_of_void_fn *)ossl_b2i_RSA_after_header

static void rsa_adjust(void *key, struct msblob2key_ctx_st *ctx)

{

    ossl_rsa_set0_libctx(key, PROV_LIBCTX_OF(ctx->provctx));

}

#define rsa_free                        (void (*)(void *))RSA_free

/* ---------------------------------------------------------------------- */

#define IMPLEMENT_MSBLOB(KEYTYPE, keytype)                              \

    static const struct keytype_desc_st mstype##2##keytype##_desc = {   \

        EVP_PKEY_##KEYTYPE, #KEYTYPE,                                   \

        ossl_##keytype##_keymgmt_functions,                             \

        keytype##_decode_private_key,                                   \

        keytype##_decode_public_key,                                    \

        keytype##_adjust,                                               \

        keytype##_free                                                  \

    };                                                                  \

    static OSSL_FUNC_decoder_newctx_fn msblob2##keytype##_newctx;       \

    static void *msblob2##keytype##_newctx(void *provctx)               \

    {                                                                   \

        return msblob2key_newctx(provctx, &mstype##2##keytype##_desc);  \

    }                                                                   \

decode_msblob2key.c:msblob2dsa_newctx

Line

Count

Source

254

146k

    {                                                                   \

255

146k

        return msblob2key_newctx(provctx, &mstype##2##keytype##_desc);  \

256

146k

    }                                                                   \

decode_msblob2key.c:msblob2rsa_newctx

Line

Count

Source

254

89.4k

    {                                                                   \

255

89.4k

        return msblob2key_newctx(provctx, &mstype##2##keytype##_desc);  \

256

89.4k

    }                                                                   \

    const OSSL_DISPATCH                                                 \

    ossl_msblob_to_##keytype##_decoder_functions[] = {                  \

        { OSSL_FUNC_DECODER_NEWCTX,                                     \

          (void (*)(void))msblob2##keytype##_newctx },                  \

        { OSSL_FUNC_DECODER_FREECTX,                                    \

          (void (*)(void))msblob2key_freectx },                         \

        { OSSL_FUNC_DECODER_DECODE,                                     \

          (void (*)(void))msblob2key_decode },                          \

        { OSSL_FUNC_DECODER_EXPORT_OBJECT,                              \

          (void (*)(void))msblob2key_export_object },                   \

        { 0, NULL }                                                     \

    }

#ifndef OPENSSL_NO_DSA

IMPLEMENT_MSBLOB(DSA, dsa);

#endif

IMPLEMENT_MSBLOB(RSA, rsa);