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