proxmark3/common/mbedtls/pk.c

/*
 *  Public Key abstraction layer
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: GPL-2.0
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */

#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#if defined(MBEDTLS_PK_C)
#include "mbedtls/pk.h"
#include "mbedtls/pk_internal.h"

#include "mbedtls/platform_util.h"

#if defined(MBEDTLS_RSA_C)
#include "mbedtls/rsa.h"
#endif
#if defined(MBEDTLS_ECP_C)
#include "mbedtls/ecp.h"
#endif
#if defined(MBEDTLS_ECDSA_C)
#include "mbedtls/ecdsa.h"
#endif

#include <limits.h>
#include <stdint.h>

/*
 * Initialise a mbedtls_pk_context
 */
void mbedtls_pk_init(mbedtls_pk_context *ctx) {
    if (ctx == NULL)
        return;

    ctx->pk_info = NULL;
    ctx->pk_ctx = NULL;
}

/*
 * Free (the components of) a mbedtls_pk_context
 */
void mbedtls_pk_free(mbedtls_pk_context *ctx) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return;

    ctx->pk_info->ctx_free_func(ctx->pk_ctx);

    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_pk_context));
}

/*
 * Get pk_info structure from type
 */
const mbedtls_pk_info_t *mbedtls_pk_info_from_type(mbedtls_pk_type_t pk_type) {
    switch (pk_type) {
#if defined(MBEDTLS_RSA_C)
        case MBEDTLS_PK_RSA:
            return (&mbedtls_rsa_info);
#endif
#if defined(MBEDTLS_ECP_C)
        case MBEDTLS_PK_ECKEY:
            return (&mbedtls_eckey_info);
        case MBEDTLS_PK_ECKEY_DH:
            return (&mbedtls_eckeydh_info);
#endif
#if defined(MBEDTLS_ECDSA_C)
        case MBEDTLS_PK_ECDSA:
            return (&mbedtls_ecdsa_info);
#endif
        /* MBEDTLS_PK_RSA_ALT omitted on purpose */
        default:
            return (NULL);
    }
}

/*
 * Initialise context
 */
int mbedtls_pk_setup(mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info) {
    if (ctx == NULL || info == NULL || ctx->pk_info != NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if ((ctx->pk_ctx = info->ctx_alloc_func()) == NULL)
        return (MBEDTLS_ERR_PK_ALLOC_FAILED);

    ctx->pk_info = info;

    return (0);
}

#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
/*
 * Initialize an RSA-alt context
 */
int mbedtls_pk_setup_rsa_alt(mbedtls_pk_context *ctx, void *key,
                             mbedtls_pk_rsa_alt_decrypt_func decrypt_func,
                             mbedtls_pk_rsa_alt_sign_func sign_func,
                             mbedtls_pk_rsa_alt_key_len_func key_len_func) {
    mbedtls_rsa_alt_context *rsa_alt;
    const mbedtls_pk_info_t *info = &mbedtls_rsa_alt_info;

    if (ctx == NULL || ctx->pk_info != NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if ((ctx->pk_ctx = info->ctx_alloc_func()) == NULL)
        return (MBEDTLS_ERR_PK_ALLOC_FAILED);

    ctx->pk_info = info;

    rsa_alt = (mbedtls_rsa_alt_context *) ctx->pk_ctx;

    rsa_alt->key = key;
    rsa_alt->decrypt_func = decrypt_func;
    rsa_alt->sign_func = sign_func;
    rsa_alt->key_len_func = key_len_func;

    return (0);
}
#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */

/*
 * Tell if a PK can do the operations of the given type
 */
int mbedtls_pk_can_do(const mbedtls_pk_context *ctx, mbedtls_pk_type_t type) {
    /* null or NONE context can't do anything */
    if (ctx == NULL || ctx->pk_info == NULL)
        return (0);

    return (ctx->pk_info->can_do(type));
}

/*
 * Helper for mbedtls_pk_sign and mbedtls_pk_verify
 */
static inline int pk_hashlen_helper(mbedtls_md_type_t md_alg, size_t *hash_len) {
    const mbedtls_md_info_t *md_info;

    if (*hash_len != 0)
        return (0);

    if ((md_info = mbedtls_md_info_from_type(md_alg)) == NULL)
        return (-1);

    *hash_len = mbedtls_md_get_size(md_info);
    return (0);
}

/*
 * Verify a signature
 */
int mbedtls_pk_verify(mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
                      const unsigned char *hash, size_t hash_len,
                      const unsigned char *sig, size_t sig_len) {
    if (ctx == NULL || ctx->pk_info == NULL ||
            pk_hashlen_helper(md_alg, &hash_len) != 0)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if (ctx->pk_info->verify_func == NULL)
        return (MBEDTLS_ERR_PK_TYPE_MISMATCH);

    return (ctx->pk_info->verify_func(ctx->pk_ctx, md_alg, hash, hash_len,
                                      sig, sig_len));
}

/*
 * Verify a signature with options
 */
int mbedtls_pk_verify_ext(mbedtls_pk_type_t type, const void *options,
                          mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
                          const unsigned char *hash, size_t hash_len,
                          const unsigned char *sig, size_t sig_len) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if (! mbedtls_pk_can_do(ctx, type))
        return (MBEDTLS_ERR_PK_TYPE_MISMATCH);

    if (type == MBEDTLS_PK_RSASSA_PSS) {
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PKCS1_V21)
        int ret;
        const mbedtls_pk_rsassa_pss_options *pss_opts;

#if SIZE_MAX > UINT_MAX
        if (md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len)
            return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);
#endif /* SIZE_MAX > UINT_MAX */

        if (options == NULL)
            return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

        pss_opts = (const mbedtls_pk_rsassa_pss_options *) options;

        if (sig_len < mbedtls_pk_get_len(ctx))
            return (MBEDTLS_ERR_RSA_VERIFY_FAILED);

        ret = mbedtls_rsa_rsassa_pss_verify_ext(mbedtls_pk_rsa(*ctx),
                                                NULL, NULL, MBEDTLS_RSA_PUBLIC,
                                                md_alg, (unsigned int) hash_len, hash,
                                                pss_opts->mgf1_hash_id,
                                                pss_opts->expected_salt_len,
                                                sig);
        if (ret != 0)
            return (ret);

        if (sig_len > mbedtls_pk_get_len(ctx))
            return (MBEDTLS_ERR_PK_SIG_LEN_MISMATCH);

        return (0);
#else
        return (MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE);
#endif /* MBEDTLS_RSA_C && MBEDTLS_PKCS1_V21 */
    }

    /* General case: no options */
    if (options != NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    return (mbedtls_pk_verify(ctx, md_alg, hash, hash_len, sig, sig_len));
}

/*
 * Make a signature
 */
int mbedtls_pk_sign(mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) {
    if (ctx == NULL || ctx->pk_info == NULL ||
            pk_hashlen_helper(md_alg, &hash_len) != 0)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if (ctx->pk_info->sign_func == NULL)
        return (MBEDTLS_ERR_PK_TYPE_MISMATCH);

    return (ctx->pk_info->sign_func(ctx->pk_ctx, md_alg, hash, hash_len,
                                    sig, sig_len, f_rng, p_rng));
}

/*
 * Decrypt message
 */
int mbedtls_pk_decrypt(mbedtls_pk_context *ctx,
                       const unsigned char *input, size_t ilen,
                       unsigned char *output, size_t *olen, size_t osize,
                       int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if (ctx->pk_info->decrypt_func == NULL)
        return (MBEDTLS_ERR_PK_TYPE_MISMATCH);

    return (ctx->pk_info->decrypt_func(ctx->pk_ctx, input, ilen,
                                       output, olen, osize, f_rng, p_rng));
}

/*
 * Encrypt message
 */
int mbedtls_pk_encrypt(mbedtls_pk_context *ctx,
                       const unsigned char *input, size_t ilen,
                       unsigned char *output, size_t *olen, size_t osize,
                       int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if (ctx->pk_info->encrypt_func == NULL)
        return (MBEDTLS_ERR_PK_TYPE_MISMATCH);

    return (ctx->pk_info->encrypt_func(ctx->pk_ctx, input, ilen,
                                       output, olen, osize, f_rng, p_rng));
}

/*
 * Check public-private key pair
 */
int mbedtls_pk_check_pair(const mbedtls_pk_context *pub, const mbedtls_pk_context *prv) {
    if (pub == NULL || pub->pk_info == NULL ||
            prv == NULL || prv->pk_info == NULL ||
            prv->pk_info->check_pair_func == NULL) {
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);
    }

    if (prv->pk_info->type == MBEDTLS_PK_RSA_ALT) {
        if (pub->pk_info->type != MBEDTLS_PK_RSA)
            return (MBEDTLS_ERR_PK_TYPE_MISMATCH);
    } else {
        if (pub->pk_info != prv->pk_info)
            return (MBEDTLS_ERR_PK_TYPE_MISMATCH);
    }

    return (prv->pk_info->check_pair_func(pub->pk_ctx, prv->pk_ctx));
}

/*
 * Get key size in bits
 */
size_t mbedtls_pk_get_bitlen(const mbedtls_pk_context *ctx) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return (0);

    return (ctx->pk_info->get_bitlen(ctx->pk_ctx));
}

/*
 * Export debug information
 */
int mbedtls_pk_debug(const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    if (ctx->pk_info->debug_func == NULL)
        return (MBEDTLS_ERR_PK_TYPE_MISMATCH);

    ctx->pk_info->debug_func(ctx->pk_ctx, items);
    return (0);
}

/*
 * Access the PK type name
 */
const char *mbedtls_pk_get_name(const mbedtls_pk_context *ctx) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return ("invalid PK");

    return (ctx->pk_info->name);
}

/*
 * Access the PK type
 */
mbedtls_pk_type_t mbedtls_pk_get_type(const mbedtls_pk_context *ctx) {
    if (ctx == NULL || ctx->pk_info == NULL)
        return (MBEDTLS_PK_NONE);

    return (ctx->pk_info->type);
}

#endif /* MBEDTLS_PK_C */