scrypt-1.2.1/lib/crypto/crypto_scrypt-ref.c

   1 /*-
   2  * Copyright 2009 Colin Percival
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * This file was originally written by Colin Percival as part of the Tarsnap
  27  * online backup system.
  28  */
  29 #include "scrypt_platform.h"
  30
  31 #include <errno.h>
  32 #include <stdint.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #include "sha256.h"
  37 #include "sysendian.h"
  38
  39 #include "crypto_scrypt.h"
  40
  41 static void blkcpy(uint8_t *, uint8_t *, size_t);
  42 static void blkxor(uint8_t *, uint8_t *, size_t);
  43 static void salsa20_8(uint8_t[64]);
  44 static void blockmix_salsa8(uint8_t *, uint8_t *, size_t);
  45 static uint64_t integerify(uint8_t *, size_t);
  46 static void smix(uint8_t *, size_t, uint64_t, uint8_t *, uint8_t *);
  47
  48 static void
  49 blkcpy(uint8_t * dest, uint8_t * src, size_t len)
  50 {
  51         size_t i;
  52
  53         for (i = 0; i < len; i++)
  54                 dest[i] = src[i];
  55 }
  56
  57 static void
  58 blkxor(uint8_t * dest, uint8_t * src, size_t len)
  59 {
  60         size_t i;
  61
  62         for (i = 0; i < len; i++)
  63                 dest[i] ^= src[i];
  64 }
  65
  66 /**
  67  * salsa20_8(B):
  68  * Apply the salsa20/8 core to the provided block.
  69  */
  70 static void
  71 salsa20_8(uint8_t B[64])
  72 {
  73         uint32_t B32[16];
  74         uint32_t x[16];
  75         size_t i;
  76
  77         /* Convert little-endian values in. */
  78         for (i = 0; i < 16; i++)
  79                 B32[i] = le32dec(&B[i * 4]);
  80
  81         /* Compute x = doubleround^4(B32). */
  82         for (i = 0; i < 16; i++)
  83                 x[i] = B32[i];
  84         for (i = 0; i < 8; i += 2) {
  85 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
  86                 /* Operate on columns. */
  87                 x[ 4] ^= R(x[ 0]+x[12], 7);  x[ 8] ^= R(x[ 4]+x[ 0], 9);
  88                 x[12] ^= R(x[ 8]+x[ 4],13);  x[ 0] ^= R(x[12]+x[ 8],18);
  89
  90                 x[ 9] ^= R(x[ 5]+x[ 1], 7);  x[13] ^= R(x[ 9]+x[ 5], 9);
  91                 x[ 1] ^= R(x[13]+x[ 9],13);  x[ 5] ^= R(x[ 1]+x[13],18);
  92
  93                 x[14] ^= R(x[10]+x[ 6], 7);  x[ 2] ^= R(x[14]+x[10], 9);
  94                 x[ 6] ^= R(x[ 2]+x[14],13);  x[10] ^= R(x[ 6]+x[ 2],18);
  95
  96                 x[ 3] ^= R(x[15]+x[11], 7);  x[ 7] ^= R(x[ 3]+x[15], 9);
  97                 x[11] ^= R(x[ 7]+x[ 3],13);  x[15] ^= R(x[11]+x[ 7],18);
  98
  99                 /* Operate on rows. */
 100                 x[ 1] ^= R(x[ 0]+x[ 3], 7);  x[ 2] ^= R(x[ 1]+x[ 0], 9);
 101                 x[ 3] ^= R(x[ 2]+x[ 1],13);  x[ 0] ^= R(x[ 3]+x[ 2],18);
 102
 103                 x[ 6] ^= R(x[ 5]+x[ 4], 7);  x[ 7] ^= R(x[ 6]+x[ 5], 9);
 104                 x[ 4] ^= R(x[ 7]+x[ 6],13);  x[ 5] ^= R(x[ 4]+x[ 7],18);
 105
 106                 x[11] ^= R(x[10]+x[ 9], 7);  x[ 8] ^= R(x[11]+x[10], 9);
 107                 x[ 9] ^= R(x[ 8]+x[11],13);  x[10] ^= R(x[ 9]+x[ 8],18);
 108
 109                 x[12] ^= R(x[15]+x[14], 7);  x[13] ^= R(x[12]+x[15], 9);
 110                 x[14] ^= R(x[13]+x[12],13);  x[15] ^= R(x[14]+x[13],18);
 111 #undef R
 112         }
 113
 114         /* Compute B32 = B32 + x. */
 115         for (i = 0; i < 16; i++)
 116                 B32[i] += x[i];
 117
 118         /* Convert little-endian values out. */
 119         for (i = 0; i < 16; i++)
 120                 le32enc(&B[4 * i], B32[i]);
 121 }
 122
 123 /**
 124  * blockmix_salsa8(B, Y, r):
 125  * Compute B = BlockMix_{salsa20/8, r}(B).  The input B must be 128r bytes in
 126  * length; the temporary space Y must also be the same size.
 127  */
 128 static void
 129 blockmix_salsa8(uint8_t * B, uint8_t * Y, size_t r)
 130 {
 131         uint8_t X[64];
 132         size_t i;
 133
 134         /* 1: X <-- B_{2r - 1} */
 135         blkcpy(X, &B[(2 * r - 1) * 64], 64);
 136
 137         /* 2: for i = 0 to 2r - 1 do */
 138         for (i = 0; i < 2 * r; i++) {
 139                 /* 3: X <-- H(X \xor B_i) */
 140                 blkxor(X, &B[i * 64], 64);
 141                 salsa20_8(X);
 142
 143                 /* 4: Y_i <-- X */
 144                 blkcpy(&Y[i * 64], X, 64);
 145         }
 146
 147         /* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
 148         for (i = 0; i < r; i++)
 149                 blkcpy(&B[i * 64], &Y[(i * 2) * 64], 64);
 150         for (i = 0; i < r; i++)
 151                 blkcpy(&B[(i + r) * 64], &Y[(i * 2 + 1) * 64], 64);
 152 }
 153
 154 /**
 155  * integerify(B, r):
 156  * Return the result of parsing B_{2r-1} as a little-endian integer.
 157  */
 158 static uint64_t
 159 integerify(uint8_t * B, size_t r)
 160 {
 161         uint8_t * X = &B[(2 * r - 1) * 64];
 162
 163         return (le64dec(X));
 164 }
 165
 166 /**
 167  * smix(B, r, N, V, XY):
 168  * Compute B = SMix_r(B, N).  The input B must be 128r bytes in length; the
 169  * temporary storage V must be 128rN bytes in length; the temporary storage
 170  * XY must be 256r bytes in length.  The value N must be a power of 2.
 171  */
 172 static void
 173 smix(uint8_t * B, size_t r, uint64_t N, uint8_t * V, uint8_t * XY)
 174 {
 175         uint8_t * X = XY;
 176         uint8_t * Y = &XY[128 * r];
 177         uint64_t i;
 178         uint64_t j;
 179
 180         /* 1: X <-- B */
 181         blkcpy(X, B, 128 * r);
 182
 183         /* 2: for i = 0 to N - 1 do */
 184         for (i = 0; i < N; i++) {
 185                 /* 3: V_i <-- X */
 186                 blkcpy(&V[i * (128 * r)], X, 128 * r);
 187
 188                 /* 4: X <-- H(X) */
 189                 blockmix_salsa8(X, Y, r);
 190         }
 191
 192         /* 6: for i = 0 to N - 1 do */
 193         for (i = 0; i < N; i++) {
 194                 /* 7: j <-- Integerify(X) mod N */
 195                 j = integerify(X, r) & (N - 1);
 196
 197                 /* 8: X <-- H(X \xor V_j) */
 198                 blkxor(X, &V[j * (128 * r)], 128 * r);
 199                 blockmix_salsa8(X, Y, r);
 200         }
 201
 202         /* 10: B' <-- X */
 203         blkcpy(B, X, 128 * r);
 204 }
 205
 206 /**
 207  * crypto_scrypt(passwd, passwdlen, salt, saltlen, N, r, p, buf, buflen):
 208  * Compute scrypt(passwd[0 .. passwdlen - 1], salt[0 .. saltlen - 1], N, r,
 209  * p, buflen) and write the result into buf.  The parameters r, p, and buflen
 210  * must satisfy r * p < 2^30 and buflen <= (2^32 - 1) * 32.  The parameter N
 211  * must be a power of 2.
 212  *
 213  * Return 0 on success; or -1 on error.
 214  */
 215 int
 216 crypto_scrypt(const uint8_t * passwd, size_t passwdlen,
 217     const uint8_t * salt, size_t saltlen, uint64_t N, uint32_t _r, uint32_t _p,
 218     uint8_t * buf, size_t buflen)
 219 {
 220         uint8_t * B;
 221         uint8_t * V;
 222         uint8_t * XY;
 223         size_t r = _r, p = _p;
 224         uint32_t i;
 225
 226         /* Sanity-check parameters. */
 227 #if SIZE_MAX > UINT32_MAX
 228         if (buflen > (((uint64_t)(1) << 32) - 1) * 32) {
 229                 errno = EFBIG;
 230                 goto err0;
 231         }
 232 #endif
 233         if ((uint64_t)(r) * (uint64_t)(p) >= (1 << 30)) {
 234                 errno = EFBIG;
 235                 goto err0;
 236         }
 237         if (((N & (N - 1)) != 0) || (N == 0)) {
 238                 errno = EINVAL;
 239                 goto err0;
 240         }
 241         if ((r > SIZE_MAX / 128 / p) ||
 242 #if SIZE_MAX / 256 <= UINT32_MAX
 243             (r > SIZE_MAX / 256) ||
 244 #endif
 245             (N > SIZE_MAX / 128 / r)) {
 246                 errno = ENOMEM;
 247                 goto err0;
 248         }
 249
 250         /* Allocate memory. */
 251         if ((B = malloc(128 * r * p)) == NULL)
 252                 goto err0;
 253         if ((XY = malloc(256 * r)) == NULL)
 254                 goto err1;
 255         if ((V = malloc(128 * r * N)) == NULL)
 256                 goto err2;
 257
 258         /* 1: (B_0 ... B_{p-1}) <-- PBKDF2(P, S, 1, p * MFLen) */
 259         PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, 1, B, p * 128 * r);
 260
 261         /* 2: for i = 0 to p - 1 do */
 262         for (i = 0; i < p; i++) {
 263                 /* 3: B_i <-- MF(B_i, N) */
 264                 smix(&B[i * 128 * r], r, N, V, XY);
 265         }
 266
 267         /* 5: DK <-- PBKDF2(P, B, 1, dkLen) */
 268         PBKDF2_SHA256(passwd, passwdlen, B, p * 128 * r, 1, buf, buflen);
 269
 270         /* Free memory. */
 271         free(V);
 272         free(XY);
 273         free(B);
 274
 275         /* Success! */
 276         return (0);
 277
 278 err2:
 279         free(XY);
 280 err1:
 281         free(B);
 282 err0:
 283         /* Failure! */
 284         return (-1);
 285 }