md.h

00001  /**
00002  * \file md.h
00003  *
00004  * \brief This file contains the generic message-digest wrapper.
00005  *
00006  * \author Adriaan de Jong <dejong@fox-it.com>
00007  */
00008 /*
00009  *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
00010  *  SPDX-License-Identifier: Apache-2.0
00011  *
00012  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00013  *  not use this file except in compliance with the License.
00014  *  You may obtain a copy of the License at
00015  *
00016  *  http://www.apache.org/licenses/LICENSE-2.0
00017  *
00018  *  Unless required by applicable law or agreed to in writing, software
00019  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00020  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00021  *  See the License for the specific language governing permissions and
00022  *  limitations under the License.
00023  *
00024  *  This file is part of Mbed TLS (https://tls.mbed.org)
00025  */
00026 
00027 #ifndef MBEDTLS_MD_H
00028 #define MBEDTLS_MD_H
00029 
00030 #include <stddef.h>
00031 
00032 #if !defined(MBEDTLS_CONFIG_FILE)
00033 #include "mbedtls/config.h"
00034 #else
00035 #include MBEDTLS_CONFIG_FILE
00036 #endif
00037 
00038 #define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE                -0x5080  /**< The selected feature is not available. */
00039 #define MBEDTLS_ERR_MD_BAD_INPUT_DATA                     -0x5100  /**< Bad input parameters to function. */
00040 #define MBEDTLS_ERR_MD_ALLOC_FAILED                       -0x5180  /**< Failed to allocate memory. */
00041 #define MBEDTLS_ERR_MD_FILE_IO_ERROR                      -0x5200  /**< Opening or reading of file failed. */
00042 
00043 /* MBEDTLS_ERR_MD_HW_ACCEL_FAILED is deprecated and should not be used. */
00044 #define MBEDTLS_ERR_MD_HW_ACCEL_FAILED                    -0x5280  /**< MD hardware accelerator failed. */
00045 
00046 #ifdef __cplusplus
00047 extern "C" {
00048 #endif
00049 
00050 /**
00051  * \brief     Supported message digests.
00052  *
00053  * \warning   MD2, MD4, MD5 and SHA-1 are considered weak message digests and
00054  *            their use constitutes a security risk. We recommend considering
00055  *            stronger message digests instead.
00056  *
00057  */
00058 typedef enum {
00059     MBEDTLS_MD_NONE=0,    /**< None. */
00060     MBEDTLS_MD_MD2,       /**< The MD2 message digest. */
00061     MBEDTLS_MD_MD4,       /**< The MD4 message digest. */
00062     MBEDTLS_MD_MD5,       /**< The MD5 message digest. */
00063     MBEDTLS_MD_SHA1,      /**< The SHA-1 message digest. */
00064     MBEDTLS_MD_SHA224,    /**< The SHA-224 message digest. */
00065     MBEDTLS_MD_SHA256,    /**< The SHA-256 message digest. */
00066     MBEDTLS_MD_SHA384,    /**< The SHA-384 message digest. */
00067     MBEDTLS_MD_SHA512,    /**< The SHA-512 message digest. */
00068     MBEDTLS_MD_RIPEMD160, /**< The RIPEMD-160 message digest. */
00069 } mbedtls_md_type_t;
00070 
00071 #if defined(MBEDTLS_SHA512_C)
00072 #define MBEDTLS_MD_MAX_SIZE         64  /* longest known is SHA512 */
00073 #else
00074 #define MBEDTLS_MD_MAX_SIZE         32  /* longest known is SHA256 or less */
00075 #endif
00076 
00077 #if defined(MBEDTLS_SHA512_C)
00078 #define MBEDTLS_MD_MAX_BLOCK_SIZE         128
00079 #else
00080 #define MBEDTLS_MD_MAX_BLOCK_SIZE         64
00081 #endif
00082 
00083 /**
00084  * Opaque struct defined in md_internal.h.
00085  */
00086 typedef struct mbedtls_md_info_t mbedtls_md_info_t;
00087 
00088 /**
00089  * The generic message-digest context.
00090  */
00091 typedef struct mbedtls_md_context_t
00092 {
00093     /** Information about the associated message digest. */
00094     const mbedtls_md_info_t *md_info;
00095 
00096     /** The digest-specific context. */
00097     void *md_ctx;
00098 
00099     /** The HMAC part of the context. */
00100     void *hmac_ctx;
00101 } mbedtls_md_context_t;
00102 
00103 /**
00104  * \brief           This function returns the list of digests supported by the
00105  *                  generic digest module.
00106  *
00107  * \return          A statically allocated array of digests. Each element
00108  *                  in the returned list is an integer belonging to the
00109  *                  message-digest enumeration #mbedtls_md_type_t.
00110  *                  The last entry is 0.
00111  */
00112 const int *mbedtls_md_list( void );
00113 
00114 /**
00115  * \brief           This function returns the message-digest information
00116  *                  associated with the given digest name.
00117  *
00118  * \param md_name   The name of the digest to search for.
00119  *
00120  * \return          The message-digest information associated with \p md_name.
00121  * \return          NULL if the associated message-digest information is not found.
00122  */
00123 const mbedtls_md_info_t *mbedtls_md_info_from_string( const char *md_name );
00124 
00125 /**
00126  * \brief           This function returns the message-digest information
00127  *                  associated with the given digest type.
00128  *
00129  * \param md_type   The type of digest to search for.
00130  *
00131  * \return          The message-digest information associated with \p md_type.
00132  * \return          NULL if the associated message-digest information is not found.
00133  */
00134 const mbedtls_md_info_t *mbedtls_md_info_from_type( mbedtls_md_type_t md_type );
00135 
00136 /**
00137  * \brief           This function initializes a message-digest context without
00138  *                  binding it to a particular message-digest algorithm.
00139  *
00140  *                  This function should always be called first. It prepares the
00141  *                  context for mbedtls_md_setup() for binding it to a
00142  *                  message-digest algorithm.
00143  */
00144 void mbedtls_md_init( mbedtls_md_context_t *ctx );
00145 
00146 /**
00147  * \brief           This function clears the internal structure of \p ctx and
00148  *                  frees any embedded internal structure, but does not free
00149  *                  \p ctx itself.
00150  *
00151  *                  If you have called mbedtls_md_setup() on \p ctx, you must
00152  *                  call mbedtls_md_free() when you are no longer using the
00153  *                  context.
00154  *                  Calling this function if you have previously
00155  *                  called mbedtls_md_init() and nothing else is optional.
00156  *                  You must not call this function if you have not called
00157  *                  mbedtls_md_init().
00158  */
00159 void mbedtls_md_free( mbedtls_md_context_t *ctx );
00160 
00161 #if ! defined(MBEDTLS_DEPRECATED_REMOVED)
00162 #if defined(MBEDTLS_DEPRECATED_WARNING)
00163 #define MBEDTLS_DEPRECATED    __attribute__((deprecated))
00164 #else
00165 #define MBEDTLS_DEPRECATED
00166 #endif
00167 /**
00168  * \brief           This function selects the message digest algorithm to use,
00169  *                  and allocates internal structures.
00170  *
00171  *                  It should be called after mbedtls_md_init() or mbedtls_md_free().
00172  *                  Makes it necessary to call mbedtls_md_free() later.
00173  *
00174  * \deprecated      Superseded by mbedtls_md_setup() in 2.0.0
00175  *
00176  * \param ctx       The context to set up.
00177  * \param md_info   The information structure of the message-digest algorithm
00178  *                  to use.
00179  *
00180  * \return          \c 0 on success.
00181  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00182  *                  failure.
00183  * \return          #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure.
00184  */
00185 int mbedtls_md_init_ctx( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info ) MBEDTLS_DEPRECATED;
00186 #undef MBEDTLS_DEPRECATED
00187 #endif /* MBEDTLS_DEPRECATED_REMOVED */
00188 
00189 /**
00190  * \brief           This function selects the message digest algorithm to use,
00191  *                  and allocates internal structures.
00192  *
00193  *                  It should be called after mbedtls_md_init() or
00194  *                  mbedtls_md_free(). Makes it necessary to call
00195  *                  mbedtls_md_free() later.
00196  *
00197  * \param ctx       The context to set up.
00198  * \param md_info   The information structure of the message-digest algorithm
00199  *                  to use.
00200  * \param hmac      Defines if HMAC is used. 0: HMAC is not used (saves some memory),
00201  *                  or non-zero: HMAC is used with this context.
00202  *
00203  * \return          \c 0 on success.
00204  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00205  *                  failure.
00206  * \return          #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure.
00207  */
00208 int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac );
00209 
00210 /**
00211  * \brief           This function clones the state of an message-digest
00212  *                  context.
00213  *
00214  * \note            You must call mbedtls_md_setup() on \c dst before calling
00215  *                  this function.
00216  *
00217  * \note            The two contexts must have the same type,
00218  *                  for example, both are SHA-256.
00219  *
00220  * \warning         This function clones the message-digest state, not the
00221  *                  HMAC state.
00222  *
00223  * \param dst       The destination context.
00224  * \param src       The context to be cloned.
00225  *
00226  * \return          \c 0 on success.
00227  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.
00228  */
00229 int mbedtls_md_clone( mbedtls_md_context_t *dst,
00230                       const mbedtls_md_context_t *src );
00231 
00232 /**
00233  * \brief           This function extracts the message-digest size from the
00234  *                  message-digest information structure.
00235  *
00236  * \param md_info   The information structure of the message-digest algorithm
00237  *                  to use.
00238  *
00239  * \return          The size of the message-digest output in Bytes.
00240  */
00241 unsigned char mbedtls_md_get_size( const mbedtls_md_info_t *md_info );
00242 
00243 /**
00244  * \brief           This function extracts the message-digest type from the
00245  *                  message-digest information structure.
00246  *
00247  * \param md_info   The information structure of the message-digest algorithm
00248  *                  to use.
00249  *
00250  * \return          The type of the message digest.
00251  */
00252 mbedtls_md_type_t mbedtls_md_get_type( const mbedtls_md_info_t *md_info );
00253 
00254 /**
00255  * \brief           This function extracts the message-digest name from the
00256  *                  message-digest information structure.
00257  *
00258  * \param md_info   The information structure of the message-digest algorithm
00259  *                  to use.
00260  *
00261  * \return          The name of the message digest.
00262  */
00263 const char *mbedtls_md_get_name( const mbedtls_md_info_t *md_info );
00264 
00265 /**
00266  * \brief           This function starts a message-digest computation.
00267  *
00268  *                  You must call this function after setting up the context
00269  *                  with mbedtls_md_setup(), and before passing data with
00270  *                  mbedtls_md_update().
00271  *
00272  * \param ctx       The generic message-digest context.
00273  *
00274  * \return          \c 0 on success.
00275  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00276  *                  failure.
00277  */
00278 int mbedtls_md_starts( mbedtls_md_context_t *ctx );
00279 
00280 /**
00281  * \brief           This function feeds an input buffer into an ongoing
00282  *                  message-digest computation.
00283  *
00284  *                  You must call mbedtls_md_starts() before calling this
00285  *                  function. You may call this function multiple times.
00286  *                  Afterwards, call mbedtls_md_finish().
00287  *
00288  * \param ctx       The generic message-digest context.
00289  * \param input     The buffer holding the input data.
00290  * \param ilen      The length of the input data.
00291  *
00292  * \return          \c 0 on success.
00293  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00294  *                  failure.
00295  */
00296 int mbedtls_md_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen );
00297 
00298 /**
00299  * \brief           This function finishes the digest operation,
00300  *                  and writes the result to the output buffer.
00301  *
00302  *                  Call this function after a call to mbedtls_md_starts(),
00303  *                  followed by any number of calls to mbedtls_md_update().
00304  *                  Afterwards, you may either clear the context with
00305  *                  mbedtls_md_free(), or call mbedtls_md_starts() to reuse
00306  *                  the context for another digest operation with the same
00307  *                  algorithm.
00308  *
00309  * \param ctx       The generic message-digest context.
00310  * \param output    The buffer for the generic message-digest checksum result.
00311  *
00312  * \return          \c 0 on success.
00313  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00314  *                  failure.
00315  */
00316 int mbedtls_md_finish( mbedtls_md_context_t *ctx, unsigned char *output );
00317 
00318 /**
00319  * \brief          This function calculates the message-digest of a buffer,
00320  *                 with respect to a configurable message-digest algorithm
00321  *                 in a single call.
00322  *
00323  *                 The result is calculated as
00324  *                 Output = message_digest(input buffer).
00325  *
00326  * \param md_info  The information structure of the message-digest algorithm
00327  *                 to use.
00328  * \param input    The buffer holding the data.
00329  * \param ilen     The length of the input data.
00330  * \param output   The generic message-digest checksum result.
00331  *
00332  * \return         \c 0 on success.
00333  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00334  *                 failure.
00335  */
00336 int mbedtls_md( const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen,
00337         unsigned char *output );
00338 
00339 #if defined(MBEDTLS_FS_IO)
00340 /**
00341  * \brief          This function calculates the message-digest checksum
00342  *                 result of the contents of the provided file.
00343  *
00344  *                 The result is calculated as
00345  *                 Output = message_digest(file contents).
00346  *
00347  * \param md_info  The information structure of the message-digest algorithm
00348  *                 to use.
00349  * \param path     The input file name.
00350  * \param output   The generic message-digest checksum result.
00351  *
00352  * \return         \c 0 on success.
00353  * \return         #MBEDTLS_ERR_MD_FILE_IO_ERROR on an I/O error accessing
00354  *                 the file pointed by \p path.
00355  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info was NULL.
00356  */
00357 int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path,
00358                      unsigned char *output );
00359 #endif /* MBEDTLS_FS_IO */
00360 
00361 /**
00362  * \brief           This function sets the HMAC key and prepares to
00363  *                  authenticate a new message.
00364  *
00365  *                  Call this function after mbedtls_md_setup(), to use
00366  *                  the MD context for an HMAC calculation, then call
00367  *                  mbedtls_md_hmac_update() to provide the input data, and
00368  *                  mbedtls_md_hmac_finish() to get the HMAC value.
00369  *
00370  * \param ctx       The message digest context containing an embedded HMAC
00371  *                  context.
00372  * \param key       The HMAC secret key.
00373  * \param keylen    The length of the HMAC key in Bytes.
00374  *
00375  * \return          \c 0 on success.
00376  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00377  *                  failure.
00378  */
00379 int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const unsigned char *key,
00380                     size_t keylen );
00381 
00382 /**
00383  * \brief           This function feeds an input buffer into an ongoing HMAC
00384  *                  computation.
00385  *
00386  *                  Call mbedtls_md_hmac_starts() or mbedtls_md_hmac_reset()
00387  *                  before calling this function.
00388  *                  You may call this function multiple times to pass the
00389  *                  input piecewise.
00390  *                  Afterwards, call mbedtls_md_hmac_finish().
00391  *
00392  * \param ctx       The message digest context containing an embedded HMAC
00393  *                  context.
00394  * \param input     The buffer holding the input data.
00395  * \param ilen      The length of the input data.
00396  *
00397  * \return          \c 0 on success.
00398  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00399  *                  failure.
00400  */
00401 int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const unsigned char *input,
00402                     size_t ilen );
00403 
00404 /**
00405  * \brief           This function finishes the HMAC operation, and writes
00406  *                  the result to the output buffer.
00407  *
00408  *                  Call this function after mbedtls_md_hmac_starts() and
00409  *                  mbedtls_md_hmac_update() to get the HMAC value. Afterwards
00410  *                  you may either call mbedtls_md_free() to clear the context,
00411  *                  or call mbedtls_md_hmac_reset() to reuse the context with
00412  *                  the same HMAC key.
00413  *
00414  * \param ctx       The message digest context containing an embedded HMAC
00415  *                  context.
00416  * \param output    The generic HMAC checksum result.
00417  *
00418  * \return          \c 0 on success.
00419  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00420  *                  failure.
00421  */
00422 int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, unsigned char *output);
00423 
00424 /**
00425  * \brief           This function prepares to authenticate a new message with
00426  *                  the same key as the previous HMAC operation.
00427  *
00428  *                  You may call this function after mbedtls_md_hmac_finish().
00429  *                  Afterwards call mbedtls_md_hmac_update() to pass the new
00430  *                  input.
00431  *
00432  * \param ctx       The message digest context containing an embedded HMAC
00433  *                  context.
00434  *
00435  * \return          \c 0 on success.
00436  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00437  *                  failure.
00438  */
00439 int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx );
00440 
00441 /**
00442  * \brief          This function calculates the full generic HMAC
00443  *                 on the input buffer with the provided key.
00444  *
00445  *                 The function allocates the context, performs the
00446  *                 calculation, and frees the context.
00447  *
00448  *                 The HMAC result is calculated as
00449  *                 output = generic HMAC(hmac key, input buffer).
00450  *
00451  * \param md_info  The information structure of the message-digest algorithm
00452  *                 to use.
00453  * \param key      The HMAC secret key.
00454  * \param keylen   The length of the HMAC secret key in Bytes.
00455  * \param input    The buffer holding the input data.
00456  * \param ilen     The length of the input data.
00457  * \param output   The generic HMAC result.
00458  *
00459  * \return         \c 0 on success.
00460  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
00461  *                 failure.
00462  */
00463 int mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const unsigned char *key, size_t keylen,
00464                 const unsigned char *input, size_t ilen,
00465                 unsigned char *output );
00466 
00467 /* Internal use */
00468 int mbedtls_md_process( mbedtls_md_context_t *ctx, const unsigned char *data );
00469 
00470 #ifdef __cplusplus
00471 }
00472 #endif
00473 
00474 #endif /* MBEDTLS_MD_H */