include/crypto/md32_common.h

   1 /*
   2  * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*-
  11  * This is a generic 32 bit "collector" for message digest algorithms.
  12  * Whenever needed it collects input character stream into chunks of
  13  * 32 bit values and invokes a block function that performs actual hash
  14  * calculations.
  15  *
  16  * Porting guide.
  17  *
  18  * Obligatory macros:
  19  *
  20  * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN
  21  *      this macro defines byte order of input stream.
  22  * HASH_CBLOCK
  23  *      size of a unit chunk HASH_BLOCK operates on.
  24  * HASH_LONG
  25  *      has to be at least 32 bit wide.
  26  * HASH_CTX
  27  *      context structure that at least contains following
  28  *      members:
  29  *              typedef struct {
  30  *                      ...
  31  *                      HASH_LONG       Nl,Nh;
  32  *                      either {
  33  *                      HASH_LONG       data[HASH_LBLOCK];
  34  *                      unsigned char   data[HASH_CBLOCK];
  35  *                      };
  36  *                      unsigned int    num;
  37  *                      ...
  38  *                      } HASH_CTX;
  39  *      data[] vector is expected to be zeroed upon first call to
  40  *      HASH_UPDATE.
  41  * HASH_UPDATE
  42  *      name of "Update" function, implemented here.
  43  * HASH_TRANSFORM
  44  *      name of "Transform" function, implemented here.
  45  * HASH_FINAL
  46  *      name of "Final" function, implemented here.
  47  * HASH_BLOCK_DATA_ORDER
  48  *      name of "block" function capable of treating *unaligned* input
  49  *      message in original (data) byte order, implemented externally.
  50  * HASH_MAKE_STRING
  51  *      macro converting context variables to an ASCII hash string.
  52  *
  53  * MD5 example:
  54  *
  55  *      #define DATA_ORDER_IS_LITTLE_ENDIAN
  56  *
  57  *      #define HASH_LONG               MD5_LONG
  58  *      #define HASH_CTX                MD5_CTX
  59  *      #define HASH_CBLOCK             MD5_CBLOCK
  60  *      #define HASH_UPDATE             MD5_Update
  61  *      #define HASH_TRANSFORM          MD5_Transform
  62  *      #define HASH_FINAL              MD5_Final
  63  *      #define HASH_BLOCK_DATA_ORDER   md5_block_data_order
  64  */
  65
  66 #include <openssl/crypto.h>
  67
  68 #if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
  69 # error "DATA_ORDER must be defined!"
  70 #endif
  71
  72 #ifndef HASH_CBLOCK
  73 # error "HASH_CBLOCK must be defined!"
  74 #endif
  75 #ifndef HASH_LONG
  76 # error "HASH_LONG must be defined!"
  77 #endif
  78 #ifndef HASH_CTX
  79 # error "HASH_CTX must be defined!"
  80 #endif
  81
  82 #ifndef HASH_UPDATE
  83 # error "HASH_UPDATE must be defined!"
  84 #endif
  85 #ifndef HASH_TRANSFORM
  86 # error "HASH_TRANSFORM must be defined!"
  87 #endif
  88 #ifndef HASH_FINAL
  89 # error "HASH_FINAL must be defined!"
  90 #endif
  91
  92 #ifndef HASH_BLOCK_DATA_ORDER
  93 # error "HASH_BLOCK_DATA_ORDER must be defined!"
  94 #endif
  95
  96 #define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
  97
  98 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
  99
 100 # define HOST_c2l(c,l)  (l =(((unsigned long)(*((c)++)))<<24),          \
 101                          l|=(((unsigned long)(*((c)++)))<<16),          \
 102                          l|=(((unsigned long)(*((c)++)))<< 8),          \
 103                          l|=(((unsigned long)(*((c)++)))    )           )
 104 # define HOST_l2c(l,c)  (*((c)++)=(unsigned char)(((l)>>24)&0xff),      \
 105                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
 106                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
 107                          *((c)++)=(unsigned char)(((l)    )&0xff),      \
 108                          l)
 109
 110 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
 111
 112 # define HOST_c2l(c,l)  (l =(((unsigned long)(*((c)++)))    ),          \
 113                          l|=(((unsigned long)(*((c)++)))<< 8),          \
 114                          l|=(((unsigned long)(*((c)++)))<<16),          \
 115                          l|=(((unsigned long)(*((c)++)))<<24)           )
 116 # define HOST_l2c(l,c)  (*((c)++)=(unsigned char)(((l)    )&0xff),      \
 117                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
 118                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
 119                          *((c)++)=(unsigned char)(((l)>>24)&0xff),      \
 120                          l)
 121
 122 #endif
 123
 124 /*
 125  * Time for some action :-)
 126  */
 127
 128 int HASH_UPDATE(HASH_CTX *c, const void *data_, size_t len)
 129 {
 130     const unsigned char *data = data_;
 131     unsigned char *p;
 132     HASH_LONG l;
 133     size_t n;
 134
 135     if (len == 0)
 136         return 1;
 137
 138     l = (c->Nl + (((HASH_LONG) len) << 3)) & 0xffffffffUL;
 139     if (l < c->Nl)              /* overflow */
 140         c->Nh++;
 141     c->Nh += (HASH_LONG) (len >> 29); /* might cause compiler warning on
 142                                        * 16-bit */
 143     c->Nl = l;
 144
 145     n = c->num;
 146     if (n != 0) {
 147         p = (unsigned char *)c->data;
 148
 149         if (len >= HASH_CBLOCK || len + n >= HASH_CBLOCK) {
 150             memcpy(p + n, data, HASH_CBLOCK - n);
 151             HASH_BLOCK_DATA_ORDER(c, p, 1);
 152             n = HASH_CBLOCK - n;
 153             data += n;
 154             len -= n;
 155             c->num = 0;
 156             /*
 157              * We use memset rather than OPENSSL_cleanse() here deliberately.
 158              * Using OPENSSL_cleanse() here could be a performance issue. It
 159              * will get properly cleansed on finalisation so this isn't a
 160              * security problem.
 161              */
 162             memset(p, 0, HASH_CBLOCK); /* keep it zeroed */
 163         } else {
 164             memcpy(p + n, data, len);
 165             c->num += (unsigned int)len;
 166             return 1;
 167         }
 168     }
 169
 170     n = len / HASH_CBLOCK;
 171     if (n > 0) {
 172         HASH_BLOCK_DATA_ORDER(c, data, n);
 173         n *= HASH_CBLOCK;
 174         data += n;
 175         len -= n;
 176     }
 177
 178     if (len != 0) {
 179         p = (unsigned char *)c->data;
 180         c->num = (unsigned int)len;
 181         memcpy(p, data, len);
 182     }
 183     return 1;
 184 }
 185
 186 void HASH_TRANSFORM(HASH_CTX *c, const unsigned char *data)
 187 {
 188     HASH_BLOCK_DATA_ORDER(c, data, 1);
 189 }
 190
 191 int HASH_FINAL(unsigned char *md, HASH_CTX *c)
 192 {
 193     unsigned char *p = (unsigned char *)c->data;
 194     size_t n = c->num;
 195
 196     p[n] = 0x80;                /* there is always room for one */
 197     n++;
 198
 199     if (n > (HASH_CBLOCK - 8)) {
 200         memset(p + n, 0, HASH_CBLOCK - n);
 201         n = 0;
 202         HASH_BLOCK_DATA_ORDER(c, p, 1);
 203     }
 204     memset(p + n, 0, HASH_CBLOCK - 8 - n);
 205
 206     p += HASH_CBLOCK - 8;
 207 #if   defined(DATA_ORDER_IS_BIG_ENDIAN)
 208     (void)HOST_l2c(c->Nh, p);
 209     (void)HOST_l2c(c->Nl, p);
 210 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
 211     (void)HOST_l2c(c->Nl, p);
 212     (void)HOST_l2c(c->Nh, p);
 213 #endif
 214     p -= HASH_CBLOCK;
 215     HASH_BLOCK_DATA_ORDER(c, p, 1);
 216     c->num = 0;
 217     OPENSSL_cleanse(p, HASH_CBLOCK);
 218
 219 #ifndef HASH_MAKE_STRING
 220 # error "HASH_MAKE_STRING must be defined!"
 221 #else
 222     HASH_MAKE_STRING(c, md);
 223 #endif
 224
 225     return 1;
 226 }
 227
 228 #ifndef MD32_REG_T
 229 # if defined(__alpha) || defined(__sparcv9) || defined(__mips)
 230 #  define MD32_REG_T long
 231 /*
 232  * This comment was originally written for MD5, which is why it
 233  * discusses A-D. But it basically applies to all 32-bit digests,
 234  * which is why it was moved to common header file.
 235  *
 236  * In case you wonder why A-D are declared as long and not
 237  * as MD5_LONG. Doing so results in slight performance
 238  * boost on LP64 architectures. The catch is we don't
 239  * really care if 32 MSBs of a 64-bit register get polluted
 240  * with eventual overflows as we *save* only 32 LSBs in
 241  * *either* case. Now declaring 'em long excuses the compiler
 242  * from keeping 32 MSBs zeroed resulting in 13% performance
 243  * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.
 244  * Well, to be honest it should say that this *prevents*
 245  * performance degradation.
 246  */
 247 # else
 248 /*
 249  * Above is not absolute and there are LP64 compilers that
 250  * generate better code if MD32_REG_T is defined int. The above
 251  * pre-processor condition reflects the circumstances under which
 252  * the conclusion was made and is subject to further extension.
 253  */
 254 #  define MD32_REG_T int
 255 # endif
 256 #endif