linux/crypto/sha256.c
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   1/*
   2 * Cryptographic API.
   3 *
   4 * SHA-256, as specified in
   5 * http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf
   6 *
   7 * SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>.
   8 *
   9 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
  10 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  11 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  12 *
  13 * This program is free software; you can redistribute it and/or modify it
  14 * under the terms of the GNU General Public License as published by the Free
  15 * Software Foundation; either version 2 of the License, or (at your option) 
  16 * any later version.
  17 *
  18 */
  19#include <linux/init.h>
  20#include <linux/module.h>
  21#include <linux/mm.h>
  22#include <linux/crypto.h>
  23#include <linux/types.h>
  24#include <asm/scatterlist.h>
  25#include <asm/byteorder.h>
  26
  27#define SHA256_DIGEST_SIZE      32
  28#define SHA256_HMAC_BLOCK_SIZE  64
  29
  30struct sha256_ctx {
  31        u32 count[2];
  32        u32 state[8];
  33        u8 buf[128];
  34};
  35
  36static inline u32 Ch(u32 x, u32 y, u32 z)
  37{
  38        return z ^ (x & (y ^ z));
  39}
  40
  41static inline u32 Maj(u32 x, u32 y, u32 z)
  42{
  43        return (x & y) | (z & (x | y));
  44}
  45
  46#define e0(x)       (ror32(x, 2) ^ ror32(x,13) ^ ror32(x,22))
  47#define e1(x)       (ror32(x, 6) ^ ror32(x,11) ^ ror32(x,25))
  48#define s0(x)       (ror32(x, 7) ^ ror32(x,18) ^ (x >> 3))
  49#define s1(x)       (ror32(x,17) ^ ror32(x,19) ^ (x >> 10))
  50
  51#define H0         0x6a09e667
  52#define H1         0xbb67ae85
  53#define H2         0x3c6ef372
  54#define H3         0xa54ff53a
  55#define H4         0x510e527f
  56#define H5         0x9b05688c
  57#define H6         0x1f83d9ab
  58#define H7         0x5be0cd19
  59
  60static inline void LOAD_OP(int I, u32 *W, const u8 *input)
  61{
  62        W[I] = __be32_to_cpu( ((__be32*)(input))[I] );
  63}
  64
  65static inline void BLEND_OP(int I, u32 *W)
  66{
  67        W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
  68}
  69
  70static void sha256_transform(u32 *state, const u8 *input)
  71{
  72        u32 a, b, c, d, e, f, g, h, t1, t2;
  73        u32 W[64];
  74        int i;
  75
  76        /* load the input */
  77        for (i = 0; i < 16; i++)
  78                LOAD_OP(i, W, input);
  79
  80        /* now blend */
  81        for (i = 16; i < 64; i++)
  82                BLEND_OP(i, W);
  83    
  84        /* load the state into our registers */
  85        a=state[0];  b=state[1];  c=state[2];  d=state[3];
  86        e=state[4];  f=state[5];  g=state[6];  h=state[7];
  87
  88        /* now iterate */
  89        t1 = h + e1(e) + Ch(e,f,g) + 0x428a2f98 + W[ 0];
  90        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
  91        t1 = g + e1(d) + Ch(d,e,f) + 0x71374491 + W[ 1];
  92        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
  93        t1 = f + e1(c) + Ch(c,d,e) + 0xb5c0fbcf + W[ 2];
  94        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
  95        t1 = e + e1(b) + Ch(b,c,d) + 0xe9b5dba5 + W[ 3];
  96        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
  97        t1 = d + e1(a) + Ch(a,b,c) + 0x3956c25b + W[ 4];
  98        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
  99        t1 = c + e1(h) + Ch(h,a,b) + 0x59f111f1 + W[ 5];
 100        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 101        t1 = b + e1(g) + Ch(g,h,a) + 0x923f82a4 + W[ 6];
 102        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 103        t1 = a + e1(f) + Ch(f,g,h) + 0xab1c5ed5 + W[ 7];
 104        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 105
 106        t1 = h + e1(e) + Ch(e,f,g) + 0xd807aa98 + W[ 8];
 107        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 108        t1 = g + e1(d) + Ch(d,e,f) + 0x12835b01 + W[ 9];
 109        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 110        t1 = f + e1(c) + Ch(c,d,e) + 0x243185be + W[10];
 111        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 112        t1 = e + e1(b) + Ch(b,c,d) + 0x550c7dc3 + W[11];
 113        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 114        t1 = d + e1(a) + Ch(a,b,c) + 0x72be5d74 + W[12];
 115        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 116        t1 = c + e1(h) + Ch(h,a,b) + 0x80deb1fe + W[13];
 117        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 118        t1 = b + e1(g) + Ch(g,h,a) + 0x9bdc06a7 + W[14];
 119        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 120        t1 = a + e1(f) + Ch(f,g,h) + 0xc19bf174 + W[15];
 121        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 122
 123        t1 = h + e1(e) + Ch(e,f,g) + 0xe49b69c1 + W[16];
 124        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 125        t1 = g + e1(d) + Ch(d,e,f) + 0xefbe4786 + W[17];
 126        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 127        t1 = f + e1(c) + Ch(c,d,e) + 0x0fc19dc6 + W[18];
 128        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 129        t1 = e + e1(b) + Ch(b,c,d) + 0x240ca1cc + W[19];
 130        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 131        t1 = d + e1(a) + Ch(a,b,c) + 0x2de92c6f + W[20];
 132        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 133        t1 = c + e1(h) + Ch(h,a,b) + 0x4a7484aa + W[21];
 134        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 135        t1 = b + e1(g) + Ch(g,h,a) + 0x5cb0a9dc + W[22];
 136        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 137        t1 = a + e1(f) + Ch(f,g,h) + 0x76f988da + W[23];
 138        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 139
 140        t1 = h + e1(e) + Ch(e,f,g) + 0x983e5152 + W[24];
 141        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 142        t1 = g + e1(d) + Ch(d,e,f) + 0xa831c66d + W[25];
 143        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 144        t1 = f + e1(c) + Ch(c,d,e) + 0xb00327c8 + W[26];
 145        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 146        t1 = e + e1(b) + Ch(b,c,d) + 0xbf597fc7 + W[27];
 147        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 148        t1 = d + e1(a) + Ch(a,b,c) + 0xc6e00bf3 + W[28];
 149        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 150        t1 = c + e1(h) + Ch(h,a,b) + 0xd5a79147 + W[29];
 151        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 152        t1 = b + e1(g) + Ch(g,h,a) + 0x06ca6351 + W[30];
 153        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 154        t1 = a + e1(f) + Ch(f,g,h) + 0x14292967 + W[31];
 155        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 156
 157        t1 = h + e1(e) + Ch(e,f,g) + 0x27b70a85 + W[32];
 158        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 159        t1 = g + e1(d) + Ch(d,e,f) + 0x2e1b2138 + W[33];
 160        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 161        t1 = f + e1(c) + Ch(c,d,e) + 0x4d2c6dfc + W[34];
 162        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 163        t1 = e + e1(b) + Ch(b,c,d) + 0x53380d13 + W[35];
 164        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 165        t1 = d + e1(a) + Ch(a,b,c) + 0x650a7354 + W[36];
 166        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 167        t1 = c + e1(h) + Ch(h,a,b) + 0x766a0abb + W[37];
 168        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 169        t1 = b + e1(g) + Ch(g,h,a) + 0x81c2c92e + W[38];
 170        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 171        t1 = a + e1(f) + Ch(f,g,h) + 0x92722c85 + W[39];
 172        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 173
 174        t1 = h + e1(e) + Ch(e,f,g) + 0xa2bfe8a1 + W[40];
 175        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 176        t1 = g + e1(d) + Ch(d,e,f) + 0xa81a664b + W[41];
 177        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 178        t1 = f + e1(c) + Ch(c,d,e) + 0xc24b8b70 + W[42];
 179        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 180        t1 = e + e1(b) + Ch(b,c,d) + 0xc76c51a3 + W[43];
 181        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 182        t1 = d + e1(a) + Ch(a,b,c) + 0xd192e819 + W[44];
 183        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 184        t1 = c + e1(h) + Ch(h,a,b) + 0xd6990624 + W[45];
 185        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 186        t1 = b + e1(g) + Ch(g,h,a) + 0xf40e3585 + W[46];
 187        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 188        t1 = a + e1(f) + Ch(f,g,h) + 0x106aa070 + W[47];
 189        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 190
 191        t1 = h + e1(e) + Ch(e,f,g) + 0x19a4c116 + W[48];
 192        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 193        t1 = g + e1(d) + Ch(d,e,f) + 0x1e376c08 + W[49];
 194        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 195        t1 = f + e1(c) + Ch(c,d,e) + 0x2748774c + W[50];
 196        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 197        t1 = e + e1(b) + Ch(b,c,d) + 0x34b0bcb5 + W[51];
 198        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 199        t1 = d + e1(a) + Ch(a,b,c) + 0x391c0cb3 + W[52];
 200        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 201        t1 = c + e1(h) + Ch(h,a,b) + 0x4ed8aa4a + W[53];
 202        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 203        t1 = b + e1(g) + Ch(g,h,a) + 0x5b9cca4f + W[54];
 204        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 205        t1 = a + e1(f) + Ch(f,g,h) + 0x682e6ff3 + W[55];
 206        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 207
 208        t1 = h + e1(e) + Ch(e,f,g) + 0x748f82ee + W[56];
 209        t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
 210        t1 = g + e1(d) + Ch(d,e,f) + 0x78a5636f + W[57];
 211        t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
 212        t1 = f + e1(c) + Ch(c,d,e) + 0x84c87814 + W[58];
 213        t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
 214        t1 = e + e1(b) + Ch(b,c,d) + 0x8cc70208 + W[59];
 215        t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
 216        t1 = d + e1(a) + Ch(a,b,c) + 0x90befffa + W[60];
 217        t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
 218        t1 = c + e1(h) + Ch(h,a,b) + 0xa4506ceb + W[61];
 219        t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
 220        t1 = b + e1(g) + Ch(g,h,a) + 0xbef9a3f7 + W[62];
 221        t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
 222        t1 = a + e1(f) + Ch(f,g,h) + 0xc67178f2 + W[63];
 223        t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
 224
 225        state[0] += a; state[1] += b; state[2] += c; state[3] += d;
 226        state[4] += e; state[5] += f; state[6] += g; state[7] += h;
 227
 228        /* clear any sensitive info... */
 229        a = b = c = d = e = f = g = h = t1 = t2 = 0;
 230        memset(W, 0, 64 * sizeof(u32));
 231}
 232
 233static void sha256_init(struct crypto_tfm *tfm)
 234{
 235        struct sha256_ctx *sctx = crypto_tfm_ctx(tfm);
 236        sctx->state[0] = H0;
 237        sctx->state[1] = H1;
 238        sctx->state[2] = H2;
 239        sctx->state[3] = H3;
 240        sctx->state[4] = H4;
 241        sctx->state[5] = H5;
 242        sctx->state[6] = H6;
 243        sctx->state[7] = H7;
 244        sctx->count[0] = sctx->count[1] = 0;
 245}
 246
 247static void sha256_update(struct crypto_tfm *tfm, const u8 *data,
 248                          unsigned int len)
 249{
 250        struct sha256_ctx *sctx = crypto_tfm_ctx(tfm);
 251        unsigned int i, index, part_len;
 252
 253        /* Compute number of bytes mod 128 */
 254        index = (unsigned int)((sctx->count[0] >> 3) & 0x3f);
 255
 256        /* Update number of bits */
 257        if ((sctx->count[0] += (len << 3)) < (len << 3)) {
 258                sctx->count[1]++;
 259                sctx->count[1] += (len >> 29);
 260        }
 261
 262        part_len = 64 - index;
 263
 264        /* Transform as many times as possible. */
 265        if (len >= part_len) {
 266                memcpy(&sctx->buf[index], data, part_len);
 267                sha256_transform(sctx->state, sctx->buf);
 268
 269                for (i = part_len; i + 63 < len; i += 64)
 270                        sha256_transform(sctx->state, &data[i]);
 271                index = 0;
 272        } else {
 273                i = 0;
 274        }
 275        
 276        /* Buffer remaining input */
 277        memcpy(&sctx->buf[index], &data[i], len-i);
 278}
 279
 280static void sha256_final(struct crypto_tfm *tfm, u8 *out)
 281{
 282        struct sha256_ctx *sctx = crypto_tfm_ctx(tfm);
 283        __be32 *dst = (__be32 *)out;
 284        __be32 bits[2];
 285        unsigned int index, pad_len;
 286        int i;
 287        static const u8 padding[64] = { 0x80, };
 288
 289        /* Save number of bits */
 290        bits[1] = cpu_to_be32(sctx->count[0]);
 291        bits[0] = cpu_to_be32(sctx->count[1]);
 292
 293        /* Pad out to 56 mod 64. */
 294        index = (sctx->count[0] >> 3) & 0x3f;
 295        pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
 296        sha256_update(tfm, padding, pad_len);
 297
 298        /* Append length (before padding) */
 299        sha256_update(tfm, (const u8 *)bits, sizeof(bits));
 300
 301        /* Store state in digest */
 302        for (i = 0; i < 8; i++)
 303                dst[i] = cpu_to_be32(sctx->state[i]);
 304
 305        /* Zeroize sensitive information. */
 306        memset(sctx, 0, sizeof(*sctx));
 307}
 308
 309
 310static struct crypto_alg alg = {
 311        .cra_name       =       "sha256",
 312        .cra_driver_name=       "sha256-generic",
 313        .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 314        .cra_blocksize  =       SHA256_HMAC_BLOCK_SIZE,
 315        .cra_ctxsize    =       sizeof(struct sha256_ctx),
 316        .cra_module     =       THIS_MODULE,
 317        .cra_alignmask  =       3,
 318        .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
 319        .cra_u          =       { .digest = {
 320        .dia_digestsize =       SHA256_DIGEST_SIZE,
 321        .dia_init       =       sha256_init,
 322        .dia_update     =       sha256_update,
 323        .dia_final      =       sha256_final } }
 324};
 325
 326static int __init init(void)
 327{
 328        return crypto_register_alg(&alg);
 329}
 330
 331static void __exit fini(void)
 332{
 333        crypto_unregister_alg(&alg);
 334}
 335
 336module_init(init);
 337module_exit(fini);
 338
 339MODULE_LICENSE("GPL");
 340MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm");
 341
 342MODULE_ALIAS("sha256-generic");
 343
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