ns_sha256.h

00001 /*
00002  * Copyright (c) 2006-2016 ARM Limited. All rights reserved.
00003  *
00004  * SPDX-License-Identifier: LicenseRef-PBL
00005  *
00006  * Licensed under the Permissive Binary License, Version 1.0 (the "License"); you may not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  * https://www.mbed.com/licenses/PBL-1.0
00010  *
00011  * See the License for the specific language governing permissions and limitations under the License.
00012  *
00013  */
00014 /**
00015  * \file ns_sha256.h
00016  *
00017  * \brief SHA-256 cryptographic hash function
00018  *
00019  *  This file is derived from sha256.h in mbed TLS 2.3.0.
00020  *
00021  *  This file provides an API very similar to mbed TLS, either implemented
00022  *  locally, or by calling mbed TLS, depending on NS_USE_EXTERNAL_MBED_TLS.
00023  *
00024  *  Differences from mbed TLS:
00025  *
00026  *   a) ns_ prefix instead of mbedtls_;
00027  *   b) Pointers are void * instead of unsigned char * to avoid type clashes;
00028  *   c) SHA-224 not supported;
00029  *   d) Ability to output truncated hashes.
00030  */
00031 
00032 
00033 #ifndef NS_SHA256_H_
00034 #define NS_SHA256_H_
00035 
00036 #ifdef NS_USE_EXTERNAL_MBED_TLS
00037 
00038 #include <string.h>
00039 #include "mbedtls/sha256.h"
00040 
00041 typedef mbedtls_sha256_context ns_sha256_context;
00042 
00043 static inline void ns_sha256_init(ns_sha256_context *ctx)
00044 {
00045     mbedtls_sha256_init(ctx);
00046 }
00047 
00048 static inline void ns_sha256_free(ns_sha256_context *ctx)
00049 {
00050     mbedtls_sha256_free(ctx);
00051 }
00052 
00053 static inline void ns_sha256_clone(ns_sha256_context *dst,
00054                                    const ns_sha256_context *src)
00055 {
00056     mbedtls_sha256_clone(dst, src);
00057 }
00058 
00059 static inline void ns_sha256_starts(ns_sha256_context *ctx)
00060 {
00061     mbedtls_sha256_starts(ctx, 0);
00062 }
00063 
00064 static inline void ns_sha256_update(ns_sha256_context *ctx, const void *input,
00065                                     size_t ilen)
00066 {
00067     mbedtls_sha256_update(ctx, input, ilen);
00068 }
00069 
00070 static inline void ns_sha256_finish(ns_sha256_context *ctx, void *output)
00071 {
00072     mbedtls_sha256_finish(ctx, output);
00073 }
00074 
00075 static inline void ns_sha256(const void *input, size_t ilen, void *output)
00076 {
00077     mbedtls_sha256(input, ilen, output, 0);
00078 }
00079 
00080 /* Extensions to standard mbed TLS - output the first bits of a hash only */
00081 /* Number of bits must be a multiple of 32, and <=256 */
00082 static inline void ns_sha256_finish_nbits(ns_sha256_context *ctx, void *output, unsigned obits)
00083 {
00084     if (obits == 256) {
00085         mbedtls_sha256_finish(ctx, output);
00086     } else {
00087         uint8_t sha256[32];
00088         mbedtls_sha256_finish(ctx, sha256);
00089         memcpy(output, sha256, obits / 8);
00090     }
00091 }
00092 
00093 static inline void ns_sha256_nbits(const void *input, size_t ilen, void *output, unsigned obits)
00094 {
00095     if (obits == 256) {
00096         mbedtls_sha256(input, ilen, output, 0);
00097     } else {
00098         uint8_t sha256[32];
00099         mbedtls_sha256(input, ilen, sha256, 0);
00100         memcpy(output, sha256, obits / 8);
00101     }
00102 }
00103 
00104 #else /* NS_USE_EXTERNAL_MBED_TLS */
00105 
00106 #include <stddef.h>
00107 #include <stdint.h>
00108 
00109 /**
00110  * \brief          SHA-256 context structure
00111  */
00112 typedef struct
00113 {
00114     uint32_t total[2];          /*!< number of bytes processed  */
00115     uint32_t state[8];          /*!< intermediate digest state  */
00116     unsigned char buffer[64];   /*!< data block being processed */
00117 }
00118 ns_sha256_context;
00119 
00120 /**
00121  * \brief          Initialize SHA-256 context
00122  *
00123  * \param ctx      SHA-256 context to be initialized
00124  */
00125 void ns_sha256_init( ns_sha256_context *ctx );
00126 
00127 /**
00128  * \brief          Clear SHA-256 context
00129  *
00130  * \param ctx      SHA-256 context to be cleared
00131  */
00132 void ns_sha256_free( ns_sha256_context *ctx );
00133 
00134 /**
00135  * \brief          Clone (the state of) a SHA-256 context
00136  *
00137  * \param dst      The destination context
00138  * \param src      The context to be cloned
00139  */
00140 void ns_sha256_clone( ns_sha256_context *dst,
00141                       const ns_sha256_context *src );
00142 
00143 /**
00144  * \brief          SHA-256 context setup
00145  *
00146  * \param ctx      context to be initialized
00147  */
00148 void ns_sha256_starts( ns_sha256_context *ctx );
00149 
00150 /**
00151  * \brief          SHA-256 process buffer
00152  *
00153  * \param ctx      SHA-256 context
00154  * \param input    buffer holding the  data
00155  * \param ilen     length of the input data
00156  */
00157 void ns_sha256_update( ns_sha256_context *ctx, const void *input,
00158                        size_t ilen );
00159 
00160 /**
00161  * \brief          SHA-256 final digest
00162  *
00163  * \param ctx      SHA-256 context
00164  * \param output   SHA-256 checksum result
00165  */
00166 void ns_sha256_finish( ns_sha256_context *ctx, void *output );
00167 
00168 /**
00169  * \brief          SHA-256 final digest
00170  *
00171  * \param ctx      SHA-256 context
00172  * \param output   SHA-256 checksum result
00173  * \param obits    Number of bits of to output - must be multiple of 32
00174  */
00175 void ns_sha256_finish_nbits( ns_sha256_context *ctx,
00176                              void *output, unsigned obits );
00177 
00178 /**
00179  * \brief          Output = SHA-256( input buffer )
00180  *
00181  * \param input    buffer holding the  data
00182  * \param ilen     length of the input data
00183  * \param output   SHA-256 checksum result
00184  */
00185 void ns_sha256( const void *input, size_t ilen,
00186                 void *output );
00187 
00188 /**
00189  * \brief          Output = SHA-256( input buffer )
00190  *
00191  * \param input    buffer holding the  data
00192  * \param ilen     length of the input data
00193  * \param output   SHA-256 checksum result
00194  * \param obits    Number of bits of to output - must be multiple of 32
00195  */
00196 void ns_sha256_nbits( const void *input, size_t ilen,
00197                       void *output, unsigned obits );
00198 
00199 #endif /* NS_USE_EXTERNAL_MBED_TLS */
00200 
00201 
00202 #endif /* NS_SHA256_H_ */