common/mbedtls/nist_kw.h

   1 /**
   2  * \file nist_kw.h
   3  *
   4  * \brief This file provides an API for key wrapping (KW) and key wrapping with
   5  *        padding (KWP) as defined in NIST SP 800-38F.
   6  *        https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38F.pdf
   7  *
   8  *        Key wrapping specifies a deterministic authenticated-encryption mode
   9  *        of operation, according to <em>NIST SP 800-38F: Recommendation for
  10  *        Block Cipher Modes of Operation: Methods for Key Wrapping</em>. Its
  11  *        purpose is to protect cryptographic keys.
  12  *
  13  *        Its equivalent is RFC 3394 for KW, and RFC 5649 for KWP.
  14  *        https://tools.ietf.org/html/rfc3394
  15  *        https://tools.ietf.org/html/rfc5649
  16  *
  17  */
  18 /*
  19  *  Copyright The Mbed TLS Contributors
  20  *  SPDX-License-Identifier: Apache-2.0
  21  *
  22  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
  23  *  not use this file except in compliance with the License.
  24  *  You may obtain a copy of the License at
  25  *
  26  *  http://www.apache.org/licenses/LICENSE-2.0
  27  *
  28  *  Unless required by applicable law or agreed to in writing, software
  29  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  30  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  31  *  See the License for the specific language governing permissions and
  32  *  limitations under the License.
  33  */
  34
  35 #ifndef MBEDTLS_NIST_KW_H
  36 #define MBEDTLS_NIST_KW_H
  37
  38 #if !defined(MBEDTLS_CONFIG_FILE)
  39 #include "mbedtls/config.h"
  40 #else
  41 #include MBEDTLS_CONFIG_FILE
  42 #endif
  43
  44 #include "mbedtls/cipher.h"
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49
  50 typedef enum {
  51     MBEDTLS_KW_MODE_KW = 0,
  52     MBEDTLS_KW_MODE_KWP = 1
  53 } mbedtls_nist_kw_mode_t;
  54
  55 #if !defined(MBEDTLS_NIST_KW_ALT)
  56 // Regular implementation
  57 //
  58
  59 /**
  60  * \brief    The key wrapping context-type definition. The key wrapping context is passed
  61  *           to the APIs called.
  62  *
  63  * \note     The definition of this type may change in future library versions.
  64  *           Don't make any assumptions on this context!
  65  */
  66 typedef struct {
  67     mbedtls_cipher_context_t cipher_ctx;    /*!< The cipher context used. */
  68 } mbedtls_nist_kw_context;
  69
  70 #else  /* MBEDTLS_NIST_key wrapping_ALT */
  71 #include "nist_kw_alt.h"
  72 #endif /* MBEDTLS_NIST_KW_ALT */
  73
  74 /**
  75  * \brief           This function initializes the specified key wrapping context
  76  *                  to make references valid and prepare the context
  77  *                  for mbedtls_nist_kw_setkey() or mbedtls_nist_kw_free().
  78  *
  79  * \param ctx       The key wrapping context to initialize.
  80  *
  81  */
  82 void mbedtls_nist_kw_init(mbedtls_nist_kw_context *ctx);
  83
  84 /**
  85  * \brief           This function initializes the key wrapping context set in the
  86  *                  \p ctx parameter and sets the encryption key.
  87  *
  88  * \param ctx       The key wrapping context.
  89  * \param cipher    The 128-bit block cipher to use. Only AES is supported.
  90  * \param key       The Key Encryption Key (KEK).
  91  * \param keybits   The KEK size in bits. This must be acceptable by the cipher.
  92  * \param is_wrap   Specify whether the operation within the context is wrapping or unwrapping
  93  *
  94  * \return          \c 0 on success.
  95  * \return          \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for any invalid input.
  96  * \return          \c MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE for 128-bit block ciphers
  97  *                  which are not supported.
  98  * \return          cipher-specific error code on failure of the underlying cipher.
  99  */
 100 int mbedtls_nist_kw_setkey(mbedtls_nist_kw_context *ctx,
 101                            mbedtls_cipher_id_t cipher,
 102                            const unsigned char *key,
 103                            unsigned int keybits,
 104                            const int is_wrap);
 105
 106 /**
 107  * \brief   This function releases and clears the specified key wrapping context
 108  *          and underlying cipher sub-context.
 109  *
 110  * \param ctx       The key wrapping context to clear.
 111  */
 112 void mbedtls_nist_kw_free(mbedtls_nist_kw_context *ctx);
 113
 114 /**
 115  * \brief           This function encrypts a buffer using key wrapping.
 116  *
 117  * \param ctx       The key wrapping context to use for encryption.
 118  * \param mode      The key wrapping mode to use (MBEDTLS_KW_MODE_KW or MBEDTLS_KW_MODE_KWP)
 119  * \param input     The buffer holding the input data.
 120  * \param in_len    The length of the input data in Bytes.
 121  *                  The input uses units of 8 Bytes called semiblocks.
 122  *                  <ul><li>For KW mode: a multiple of 8 bytes between 16 and 2^57-8 inclusive. </li>
 123  *                  <li>For KWP mode: any length between 1 and 2^32-1 inclusive.</li></ul>
 124  * \param[out] output    The buffer holding the output data.
 125  *                  <ul><li>For KW mode: Must be at least 8 bytes larger than \p in_len.</li>
 126  *                  <li>For KWP mode: Must be at least 8 bytes larger rounded up to a multiple of
 127  *                  8 bytes for KWP (15 bytes at most).</li></ul>
 128  * \param[out] out_len The number of bytes written to the output buffer. \c 0 on failure.
 129  * \param[in] out_size The capacity of the output buffer.
 130  *
 131  * \return          \c 0 on success.
 132  * \return          \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for invalid input length.
 133  * \return          cipher-specific error code on failure of the underlying cipher.
 134  */
 135 int mbedtls_nist_kw_wrap(mbedtls_nist_kw_context *ctx, mbedtls_nist_kw_mode_t mode,
 136                          const unsigned char *input, size_t in_len,
 137                          unsigned char *output, size_t *out_len, size_t out_size);
 138
 139 /**
 140  * \brief           This function decrypts a buffer using key wrapping.
 141  *
 142  * \param ctx       The key wrapping context to use for decryption.
 143  * \param mode      The key wrapping mode to use (MBEDTLS_KW_MODE_KW or MBEDTLS_KW_MODE_KWP)
 144  * \param input     The buffer holding the input data.
 145  * \param in_len    The length of the input data in Bytes.
 146  *                  The input uses units of 8 Bytes called semiblocks.
 147  *                  The input must be a multiple of semiblocks.
 148  *                  <ul><li>For KW mode: a multiple of 8 bytes between 24 and 2^57 inclusive. </li>
 149  *                  <li>For KWP mode: a multiple of 8 bytes between 16 and 2^32 inclusive.</li></ul>
 150  * \param[out] output    The buffer holding the output data.
 151  *                  The output buffer's minimal length is 8 bytes shorter than \p in_len.
 152  * \param[out] out_len The number of bytes written to the output buffer. \c 0 on failure.
 153  *                  For KWP mode, the length could be up to 15 bytes shorter than \p in_len,
 154  *                  depending on how much padding was added to the data.
 155  * \param[in] out_size The capacity of the output buffer.
 156  *
 157  * \return          \c 0 on success.
 158  * \return          \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for invalid input length.
 159  * \return          \c MBEDTLS_ERR_CIPHER_AUTH_FAILED for verification failure of the ciphertext.
 160  * \return          cipher-specific error code on failure of the underlying cipher.
 161  */
 162 int mbedtls_nist_kw_unwrap(mbedtls_nist_kw_context *ctx, mbedtls_nist_kw_mode_t mode,
 163                            const unsigned char *input, size_t in_len,
 164                            unsigned char *output, size_t *out_len, size_t out_size);
 165
 166
 167 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
 168 /**
 169  * \brief          The key wrapping checkup routine.
 170  *
 171  * \return         \c 0 on success.
 172  * \return         \c 1 on failure.
 173  */
 174 int mbedtls_nist_kw_self_test(int verbose);
 175 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
 176
 177 #ifdef __cplusplus
 178 }
 179 #endif
 180
 181 #endif /* MBEDTLS_NIST_KW_H */