md.h

00001  /**
00002  * \file md.h
00003  *
00004  * \brief 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     Enumeration of 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,
00058     MBEDTLS_MD_MD2,
00059     MBEDTLS_MD_MD4,
00060     MBEDTLS_MD_MD5,
00061     MBEDTLS_MD_SHA1,
00062     MBEDTLS_MD_SHA224,
00063     MBEDTLS_MD_SHA256,
00064     MBEDTLS_MD_SHA384,
00065     MBEDTLS_MD_SHA512,
00066     MBEDTLS_MD_RIPEMD160,
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  *                  or NULL if 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  *                  or NULL if 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  * \returns         \c 0 on success,
00172  *                  #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter failure,
00173  *                  #MBEDTLS_ERR_MD_ALLOC_FAILED memory allocation failure.
00174  */
00175 int mbedtls_md_init_ctx( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info ) MBEDTLS_DEPRECATED;
00176 #undef MBEDTLS_DEPRECATED
00177 #endif /* MBEDTLS_DEPRECATED_REMOVED */
00178 
00179 /**
00180  * \brief           This function selects the message digest algorithm to use,
00181  *                  and allocates internal structures.
00182  *
00183  *                  It should be called after mbedtls_md_init() or
00184  *                  mbedtls_md_free(). Makes it necessary to call
00185  *                  mbedtls_md_free() later.
00186  *
00187  * \param ctx       The context to set up.
00188  * \param md_info   The information structure of the message-digest algorithm
00189  *                  to use.
00190  * \param hmac      <ul><li>0: HMAC is not used. Saves some memory.</li>
00191  *                  <li>non-zero: HMAC is used with this context.</li></ul>
00192  *
00193  * \returns         \c 0 on success,
00194  *                  #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter failure, or
00195  *                  #MBEDTLS_ERR_MD_ALLOC_FAILED on memory allocation failure.
00196  */
00197 int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac );
00198 
00199 /**
00200  * \brief           This function clones the state of an message-digest
00201  *                  context.
00202  *
00203  * \note            You must call mbedtls_md_setup() on \c dst before calling
00204  *                  this function.
00205  *
00206  * \note            The two contexts must have the same type,
00207  *                  for example, both are SHA-256.
00208  *
00209  * \warning         This function clones the message-digest state, not the
00210  *                  HMAC state.
00211  *
00212  * \param dst       The destination context.
00213  * \param src       The context to be cloned.
00214  *
00215  * \return          \c 0 on success,
00216  *                  #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter failure.
00217  */
00218 int mbedtls_md_clone( mbedtls_md_context_t *dst,
00219                       const mbedtls_md_context_t *src );
00220 
00221 /**
00222  * \brief           This function extracts the message-digest size from the
00223  *                  message-digest information structure.
00224  *
00225  * \param md_info   The information structure of the message-digest algorithm
00226  *                  to use.
00227  *
00228  * \return          The size of the message-digest output in Bytes.
00229  */
00230 unsigned char mbedtls_md_get_size( const mbedtls_md_info_t *md_info );
00231 
00232 /**
00233  * \brief           This function extracts the message-digest type 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 type of the message digest.
00240  */
00241 mbedtls_md_type_t mbedtls_md_get_type( const mbedtls_md_info_t *md_info );
00242 
00243 /**
00244  * \brief           This function extracts the message-digest name 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 name of the message digest.
00251  */
00252 const char *mbedtls_md_get_name( const mbedtls_md_info_t *md_info );
00253 
00254 /**
00255  * \brief           This function starts a message-digest computation.
00256  *
00257  *                  You must call this function after setting up the context
00258  *                  with mbedtls_md_setup(), and before passing data with
00259  *                  mbedtls_md_update().
00260  *
00261  * \param ctx       The generic message-digest context.
00262  *
00263  * \returns         \c 0 on success, #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00264  *                  parameter verification fails.
00265  */
00266 int mbedtls_md_starts( mbedtls_md_context_t *ctx );
00267 
00268 /**
00269  * \brief           This function feeds an input buffer into an ongoing
00270  *                  message-digest computation.
00271  *
00272  *                  You must call mbedtls_md_starts() before calling this
00273  *                  function. You may call this function multiple times.
00274  *                  Afterwards, call mbedtls_md_finish().
00275  *
00276  * \param ctx       The generic message-digest context.
00277  * \param input     The buffer holding the input data.
00278  * \param ilen      The length of the input data.
00279  *
00280  * \returns         \c 0 on success, #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00281  *                  parameter verification fails.
00282  */
00283 int mbedtls_md_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen );
00284 
00285 /**
00286  * \brief           This function finishes the digest operation,
00287  *                  and writes the result to the output buffer.
00288  *
00289  *                  Call this function after a call to mbedtls_md_starts(),
00290  *                  followed by any number of calls to mbedtls_md_update().
00291  *                  Afterwards, you may either clear the context with
00292  *                  mbedtls_md_free(), or call mbedtls_md_starts() to reuse
00293  *                  the context for another digest operation with the same
00294  *                  algorithm.
00295  *
00296  * \param ctx       The generic message-digest context.
00297  * \param output    The buffer for the generic message-digest checksum result.
00298  *
00299  * \returns         \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00300  *                  parameter verification fails.
00301  */
00302 int mbedtls_md_finish( mbedtls_md_context_t *ctx, unsigned char *output );
00303 
00304 /**
00305  * \brief          This function calculates the message-digest of a buffer,
00306  *                 with respect to a configurable message-digest algorithm
00307  *                 in a single call.
00308  *
00309  *                 The result is calculated as
00310  *                 Output = message_digest(input buffer).
00311  *
00312  * \param md_info  The information structure of the message-digest algorithm
00313  *                 to use.
00314  * \param input    The buffer holding the data.
00315  * \param ilen     The length of the input data.
00316  * \param output   The generic message-digest checksum result.
00317  *
00318  * \returns        \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00319  *                 parameter verification fails.
00320  */
00321 int mbedtls_md( const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen,
00322         unsigned char *output );
00323 
00324 #if defined(MBEDTLS_FS_IO)
00325 /**
00326  * \brief          This function calculates the message-digest checksum
00327  *                 result of the contents of the provided file.
00328  *
00329  *                 The result is calculated as
00330  *                 Output = message_digest(file contents).
00331  *
00332  * \param md_info  The information structure of the message-digest algorithm
00333  *                 to use.
00334  * \param path     The input file name.
00335  * \param output   The generic message-digest checksum result.
00336  *
00337  * \return         \c 0 on success,
00338  *                 #MBEDTLS_ERR_MD_FILE_IO_ERROR if file input failed, or
00339  *                 #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info was NULL.
00340  */
00341 int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path,
00342                      unsigned char *output );
00343 #endif /* MBEDTLS_FS_IO */
00344 
00345 /**
00346  * \brief           This function sets the HMAC key and prepares to
00347  *                  authenticate a new message.
00348  *
00349  *                  Call this function after mbedtls_md_setup(), to use
00350  *                  the MD context for an HMAC calculation, then call
00351  *                  mbedtls_md_hmac_update() to provide the input data, and
00352  *                  mbedtls_md_hmac_finish() to get the HMAC value.
00353  *
00354  * \param ctx       The message digest context containing an embedded HMAC
00355  *                  context.
00356  * \param key       The HMAC secret key.
00357  * \param keylen    The length of the HMAC key in Bytes.
00358  *
00359  * \returns         \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00360  *                  parameter verification fails.
00361  */
00362 int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const unsigned char *key,
00363                     size_t keylen );
00364 
00365 /**
00366  * \brief           This function feeds an input buffer into an ongoing HMAC
00367  *                  computation.
00368  *
00369  *                  Call mbedtls_md_hmac_starts() or mbedtls_md_hmac_reset()
00370  *                  before calling this function.
00371  *                  You may call this function multiple times to pass the
00372  *                  input piecewise.
00373  *                  Afterwards, call mbedtls_md_hmac_finish().
00374  *
00375  * \param ctx       The message digest context containing an embedded HMAC
00376  *                  context.
00377  * \param input     The buffer holding the input data.
00378  * \param ilen      The length of the input data.
00379  *
00380  * \returns         \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00381  *                  parameter verification fails.
00382  */
00383 int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const unsigned char *input,
00384                     size_t ilen );
00385 
00386 /**
00387  * \brief           This function finishes the HMAC operation, and writes
00388  *                  the result to the output buffer.
00389  *
00390  *                  Call this function after mbedtls_md_hmac_starts() and
00391  *                  mbedtls_md_hmac_update() to get the HMAC value. Afterwards
00392  *                  you may either call mbedtls_md_free() to clear the context,
00393  *                  or call mbedtls_md_hmac_reset() to reuse the context with
00394  *                  the same HMAC key.
00395  *
00396  * \param ctx       The message digest context containing an embedded HMAC
00397  *                  context.
00398  * \param output    The generic HMAC checksum result.
00399  *
00400  * \returns         \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00401  *                  parameter verification fails.
00402  */
00403 int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, unsigned char *output);
00404 
00405 /**
00406  * \brief           This function prepares to authenticate a new message with
00407  *                  the same key as the previous HMAC operation.
00408  *
00409  *                  You may call this function after mbedtls_md_hmac_finish().
00410  *                  Afterwards call mbedtls_md_hmac_update() to pass the new
00411  *                  input.
00412  *
00413  * \param ctx       The message digest context containing an embedded HMAC
00414  *                  context.
00415  *
00416  * \returns         \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00417  *                  parameter verification fails.
00418  */
00419 int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx );
00420 
00421 /**
00422  * \brief          This function calculates the full generic HMAC
00423  *                 on the input buffer with the provided key.
00424  *
00425  *                 The function allocates the context, performs the
00426  *                 calculation, and frees the context.
00427  *
00428  *                 The HMAC result is calculated as
00429  *                 output = generic HMAC(hmac key, input buffer).
00430  *
00431  * \param md_info  The information structure of the message-digest algorithm
00432  *                 to use.
00433  * \param key      The HMAC secret key.
00434  * \param keylen   The length of the HMAC secret key in Bytes.
00435  * \param input    The buffer holding the input data.
00436  * \param ilen     The length of the input data.
00437  * \param output   The generic HMAC result.
00438  *
00439  * \returns        \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA if
00440  *                 parameter verification fails.
00441  */
00442 int mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const unsigned char *key, size_t keylen,
00443                 const unsigned char *input, size_t ilen,
00444                 unsigned char *output );
00445 
00446 /* Internal use */
00447 int mbedtls_md_process( mbedtls_md_context_t *ctx, const unsigned char *data );
00448 
00449 #ifdef __cplusplus
00450 }
00451 #endif
00452 
00453 #endif /* MBEDTLS_MD_H */