openssl/crypto/des/set_key.c

/*
 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/*-
 * set_key.c v 1.4 eay 24/9/91
 * 1.4 Speed up by 400% :-)
 * 1.3 added register declarations.
 * 1.2 unrolled make_key_sched a bit more
 * 1.1 added norm_expand_bits
 * 1.0 First working version
 */

/*
 * DES low level APIs are deprecated for public use, but still ok for internal
 * use.
 */
#include "internal/deprecated.h"

#include <openssl/crypto.h>
#include "internal/constant_time.h"
#include "internal/nelem.h"
#include "des_local.h"

static const unsigned char odd_parity[256] = {
    1, 1, 2, 2, 4, 4, 7, 7, 8, 8, 11, 11, 13, 13, 14, 14,
    16, 16, 19, 19, 21, 21, 22, 22, 25, 25, 26, 26, 28, 28, 31, 31,
    32, 32, 35, 35, 37, 37, 38, 38, 41, 41, 42, 42, 44, 44, 47, 47,
    49, 49, 50, 50, 52, 52, 55, 55, 56, 56, 59, 59, 61, 61, 62, 62,
    64, 64, 67, 67, 69, 69, 70, 70, 73, 73, 74, 74, 76, 76, 79, 79,
    81, 81, 82, 82, 84, 84, 87, 87, 88, 88, 91, 91, 93, 93, 94, 94,
    97, 97, 98, 98, 100, 100, 103, 103, 104, 104, 107, 107, 109, 109, 110,
    110,
    112, 112, 115, 115, 117, 117, 118, 118, 121, 121, 122, 122, 124, 124, 127,
    127,
    128, 128, 131, 131, 133, 133, 134, 134, 137, 137, 138, 138, 140, 140, 143,
    143,
    145, 145, 146, 146, 148, 148, 151, 151, 152, 152, 155, 155, 157, 157, 158,
    158,
    161, 161, 162, 162, 164, 164, 167, 167, 168, 168, 171, 171, 173, 173, 174,
    174,
    176, 176, 179, 179, 181, 181, 182, 182, 185, 185, 186, 186, 188, 188, 191,
    191,
    193, 193, 194, 194, 196, 196, 199, 199, 200, 200, 203, 203, 205, 205, 206,
    206,
    208, 208, 211, 211, 213, 213, 214, 214, 217, 217, 218, 218, 220, 220, 223,
    223,
    224, 224, 227, 227, 229, 229, 230, 230, 233, 233, 234, 234, 236, 236, 239,
    239,
    241, 241, 242, 242, 244, 244, 247, 247, 248, 248, 251, 251, 253, 253, 254,
    254
};

void DES_set_odd_parity(DES_cblock *key)
{
    unsigned int i;

    for (i = 0; i < DES_KEY_SZ; i++)
        (*key)[i] = odd_parity[(*key)[i]];
}

/*
 * Check that a key has the correct parity.
 * Return 1 if parity is okay and 0 if not.
 */
int DES_check_key_parity(const_DES_cblock *key)
{
    unsigned int i;
    unsigned char res = 0377, b;

    for (i = 0; i < DES_KEY_SZ; i++) {
        b = (*key)[i];
        b ^= b >> 4;
        b ^= b >> 2;
        b ^= b >> 1;
        res &= constant_time_eq_8(b & 1, 1);
    }
    return (int)(res & 1);
}

/*-
 * Weak and semi weak keys as taken from
 * %A D.W. Davies
 * %A W.L. Price
 * %T Security for Computer Networks
 * %I John Wiley & Sons
 * %D 1984
 */
static const DES_cblock weak_keys[] = {
    /* weak keys */
    {0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01},
    {0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE},
    {0x1F, 0x1F, 0x1F, 0x1F, 0x0E, 0x0E, 0x0E, 0x0E},
    {0xE0, 0xE0, 0xE0, 0xE0, 0xF1, 0xF1, 0xF1, 0xF1},
    /* semi-weak keys */
    {0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE},
    {0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01},
    {0x1F, 0xE0, 0x1F, 0xE0, 0x0E, 0xF1, 0x0E, 0xF1},
    {0xE0, 0x1F, 0xE0, 0x1F, 0xF1, 0x0E, 0xF1, 0x0E},
    {0x01, 0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1},
    {0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1, 0x01},
    {0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E, 0xFE},
    {0xFE, 0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E},
    {0x01, 0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E},
    {0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E, 0x01},
    {0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1, 0xFE},
    {0xFE, 0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1}
};

/*
 * Check for weak keys.
 * Return 1 if the key is weak and 0 otherwise.
 */
int DES_is_weak_key(const_DES_cblock *key)
{
    unsigned int i, res = 0;
    int j;

    for (i = 0; i < OSSL_NELEM(weak_keys); i++) {
        j = CRYPTO_memcmp(weak_keys[i], key, sizeof(DES_cblock));
        res |= constant_time_is_zero((unsigned int)j);
    }
    return (int)(res & 1);
}

/*-
 * NOW DEFINED IN des_local.h
 * See ecb_encrypt.c for a pseudo description of these macros.
 * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
 *      (b)^=(t),\
 *      (a)=((a)^((t)<<(n))))
 */

#define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
        (a)=(a)^(t)^(t>>(16-(n))))

static const DES_LONG des_skb[8][64] = {
    {
     /* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
     0x00000000L, 0x00000010L, 0x20000000L, 0x20000010L,
     0x00010000L, 0x00010010L, 0x20010000L, 0x20010010L,
     0x00000800L, 0x00000810L, 0x20000800L, 0x20000810L,
     0x00010800L, 0x00010810L, 0x20010800L, 0x20010810L,
     0x00000020L, 0x00000030L, 0x20000020L, 0x20000030L,
     0x00010020L, 0x00010030L, 0x20010020L, 0x20010030L,
     0x00000820L, 0x00000830L, 0x20000820L, 0x20000830L,
     0x00010820L, 0x00010830L, 0x20010820L, 0x20010830L,
     0x00080000L, 0x00080010L, 0x20080000L, 0x20080010L,
     0x00090000L, 0x00090010L, 0x20090000L, 0x20090010L,
     0x00080800L, 0x00080810L, 0x20080800L, 0x20080810L,
     0x00090800L, 0x00090810L, 0x20090800L, 0x20090810L,
     0x00080020L, 0x00080030L, 0x20080020L, 0x20080030L,
     0x00090020L, 0x00090030L, 0x20090020L, 0x20090030L,
     0x00080820L, 0x00080830L, 0x20080820L, 0x20080830L,
     0x00090820L, 0x00090830L, 0x20090820L, 0x20090830L,
     },
    {
     /* for C bits (numbered as per FIPS 46) 7 8 10 11 12 13 */
     0x00000000L, 0x02000000L, 0x00002000L, 0x02002000L,
     0x00200000L, 0x02200000L, 0x00202000L, 0x02202000L,
     0x00000004L, 0x02000004L, 0x00002004L, 0x02002004L,
     0x00200004L, 0x02200004L, 0x00202004L, 0x02202004L,
     0x00000400L, 0x02000400L, 0x00002400L, 0x02002400L,
     0x00200400L, 0x02200400L, 0x00202400L, 0x02202400L,
     0x00000404L, 0x02000404L, 0x00002404L, 0x02002404L,
     0x00200404L, 0x02200404L, 0x00202404L, 0x02202404L,
     0x10000000L, 0x12000000L, 0x10002000L, 0x12002000L,
     0x10200000L, 0x12200000L, 0x10202000L, 0x12202000L,
     0x10000004L, 0x12000004L, 0x10002004L, 0x12002004L,
     0x10200004L, 0x12200004L, 0x10202004L, 0x12202004L,
     0x10000400L, 0x12000400L, 0x10002400L, 0x12002400L,
     0x10200400L, 0x12200400L, 0x10202400L, 0x12202400L,
     0x10000404L, 0x12000404L, 0x10002404L, 0x12002404L,
     0x10200404L, 0x12200404L, 0x10202404L, 0x12202404L,
     },
    {
     /* for C bits (numbered as per FIPS 46) 14 15 16 17 19 20 */
     0x00000000L, 0x00000001L, 0x00040000L, 0x00040001L,
     0x01000000L, 0x01000001L, 0x01040000L, 0x01040001L,
     0x00000002L, 0x00000003L, 0x00040002L, 0x00040003L,
     0x01000002L, 0x01000003L, 0x01040002L, 0x01040003L,
     0x00000200L, 0x00000201L, 0x00040200L, 0x00040201L,
     0x01000200L, 0x01000201L, 0x01040200L, 0x01040201L,
     0x00000202L, 0x00000203L, 0x00040202L, 0x00040203L,
     0x01000202L, 0x01000203L, 0x01040202L, 0x01040203L,
     0x08000000L, 0x08000001L, 0x08040000L, 0x08040001L,
     0x09000000L, 0x09000001L, 0x09040000L, 0x09040001L,
     0x08000002L, 0x08000003L, 0x08040002L, 0x08040003L,
     0x09000002L, 0x09000003L, 0x09040002L, 0x09040003L,
     0x08000200L, 0x08000201L, 0x08040200L, 0x08040201L,
     0x09000200L, 0x09000201L, 0x09040200L, 0x09040201L,
     0x08000202L, 0x08000203L, 0x08040202L, 0x08040203L,
     0x09000202L, 0x09000203L, 0x09040202L, 0x09040203L,
     },
    {
     /* for C bits (numbered as per FIPS 46) 21 23 24 26 27 28 */
     0x00000000L, 0x00100000L, 0x00000100L, 0x00100100L,
     0x00000008L, 0x00100008L, 0x00000108L, 0x00100108L,
     0x00001000L, 0x00101000L, 0x00001100L, 0x00101100L,
     0x00001008L, 0x00101008L, 0x00001108L, 0x00101108L,
     0x04000000L, 0x04100000L, 0x04000100L, 0x04100100L,
     0x04000008L, 0x04100008L, 0x04000108L, 0x04100108L,
     0x04001000L, 0x04101000L, 0x04001100L, 0x04101100L,
     0x04001008L, 0x04101008L, 0x04001108L, 0x04101108L,
     0x00020000L, 0x00120000L, 0x00020100L, 0x00120100L,
     0x00020008L, 0x00120008L, 0x00020108L, 0x00120108L,
     0x00021000L, 0x00121000L, 0x00021100L, 0x00121100L,
     0x00021008L, 0x00121008L, 0x00021108L, 0x00121108L,
     0x04020000L, 0x04120000L, 0x04020100L, 0x04120100L,
     0x04020008L, 0x04120008L, 0x04020108L, 0x04120108L,
     0x04021000L, 0x04121000L, 0x04021100L, 0x04121100L,
     0x04021008L, 0x04121008L, 0x04021108L, 0x04121108L,
     },
    {
     /* for D bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
     0x00000000L, 0x10000000L, 0x00010000L, 0x10010000L,
     0x00000004L, 0x10000004L, 0x00010004L, 0x10010004L,
     0x20000000L, 0x30000000L, 0x20010000L, 0x30010000L,
     0x20000004L, 0x30000004L, 0x20010004L, 0x30010004L,
     0x00100000L, 0x10100000L, 0x00110000L, 0x10110000L,
     0x00100004L, 0x10100004L, 0x00110004L, 0x10110004L,
     0x20100000L, 0x30100000L, 0x20110000L, 0x30110000L,
     0x20100004L, 0x30100004L, 0x20110004L, 0x30110004L,
     0x00001000L, 0x10001000L, 0x00011000L, 0x10011000L,
     0x00001004L, 0x10001004L, 0x00011004L, 0x10011004L,
     0x20001000L, 0x30001000L, 0x20011000L, 0x30011000L,
     0x20001004L, 0x30001004L, 0x20011004L, 0x30011004L,
     0x00101000L, 0x10101000L, 0x00111000L, 0x10111000L,
     0x00101004L, 0x10101004L, 0x00111004L, 0x10111004L,
     0x20101000L, 0x30101000L, 0x20111000L, 0x30111000L,
     0x20101004L, 0x30101004L, 0x20111004L, 0x30111004L,
     },
    {
     /* for D bits (numbered as per FIPS 46) 8 9 11 12 13 14 */
     0x00000000L, 0x08000000L, 0x00000008L, 0x08000008L,
     0x00000400L, 0x08000400L, 0x00000408L, 0x08000408L,
     0x00020000L, 0x08020000L, 0x00020008L, 0x08020008L,
     0x00020400L, 0x08020400L, 0x00020408L, 0x08020408L,
     0x00000001L, 0x08000001L, 0x00000009L, 0x08000009L,
     0x00000401L, 0x08000401L, 0x00000409L, 0x08000409L,
     0x00020001L, 0x08020001L, 0x00020009L, 0x08020009L,
     0x00020401L, 0x08020401L, 0x00020409L, 0x08020409L,
     0x02000000L, 0x0A000000L, 0x02000008L, 0x0A000008L,
     0x02000400L, 0x0A000400L, 0x02000408L, 0x0A000408L,
     0x02020000L, 0x0A020000L, 0x02020008L, 0x0A020008L,
     0x02020400L, 0x0A020400L, 0x02020408L, 0x0A020408L,
     0x02000001L, 0x0A000001L, 0x02000009L, 0x0A000009L,
     0x02000401L, 0x0A000401L, 0x02000409L, 0x0A000409L,
     0x02020001L, 0x0A020001L, 0x02020009L, 0x0A020009L,
     0x02020401L, 0x0A020401L, 0x02020409L, 0x0A020409L,
     },
    {
     /* for D bits (numbered as per FIPS 46) 16 17 18 19 20 21 */
     0x00000000L, 0x00000100L, 0x00080000L, 0x00080100L,
     0x01000000L, 0x01000100L, 0x01080000L, 0x01080100L,
     0x00000010L, 0x00000110L, 0x00080010L, 0x00080110L,
     0x01000010L, 0x01000110L, 0x01080010L, 0x01080110L,
     0x00200000L, 0x00200100L, 0x00280000L, 0x00280100L,
     0x01200000L, 0x01200100L, 0x01280000L, 0x01280100L,
     0x00200010L, 0x00200110L, 0x00280010L, 0x00280110L,
     0x01200010L, 0x01200110L, 0x01280010L, 0x01280110L,
     0x00000200L, 0x00000300L, 0x00080200L, 0x00080300L,
     0x01000200L, 0x01000300L, 0x01080200L, 0x01080300L,
     0x00000210L, 0x00000310L, 0x00080210L, 0x00080310L,
     0x01000210L, 0x01000310L, 0x01080210L, 0x01080310L,
     0x00200200L, 0x00200300L, 0x00280200L, 0x00280300L,
     0x01200200L, 0x01200300L, 0x01280200L, 0x01280300L,
     0x00200210L, 0x00200310L, 0x00280210L, 0x00280310L,
     0x01200210L, 0x01200310L, 0x01280210L, 0x01280310L,
     },
    {
     /* for D bits (numbered as per FIPS 46) 22 23 24 25 27 28 */
     0x00000000L, 0x04000000L, 0x00040000L, 0x04040000L,
     0x00000002L, 0x04000002L, 0x00040002L, 0x04040002L,
     0x00002000L, 0x04002000L, 0x00042000L, 0x04042000L,
     0x00002002L, 0x04002002L, 0x00042002L, 0x04042002L,
     0x00000020L, 0x04000020L, 0x00040020L, 0x04040020L,
     0x00000022L, 0x04000022L, 0x00040022L, 0x04040022L,
     0x00002020L, 0x04002020L, 0x00042020L, 0x04042020L,
     0x00002022L, 0x04002022L, 0x00042022L, 0x04042022L,
     0x00000800L, 0x04000800L, 0x00040800L, 0x04040800L,
     0x00000802L, 0x04000802L, 0x00040802L, 0x04040802L,
     0x00002800L, 0x04002800L, 0x00042800L, 0x04042800L,
     0x00002802L, 0x04002802L, 0x00042802L, 0x04042802L,
     0x00000820L, 0x04000820L, 0x00040820L, 0x04040820L,
     0x00000822L, 0x04000822L, 0x00040822L, 0x04040822L,
     0x00002820L, 0x04002820L, 0x00042820L, 0x04042820L,
     0x00002822L, 0x04002822L, 0x00042822L, 0x04042822L,
     }
};

/* Return values as DES_set_key_checked() but always set the key */
int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule)
{
    int ret = 0;

    if (!DES_check_key_parity(key))
        ret = -1;
    if (DES_is_weak_key(key))
        ret = -2;
    DES_set_key_unchecked(key, schedule);
    return ret;
}

/*-
 * return 0 if key parity is odd (correct),
 * return -1 if key parity error,
 * return -2 if illegal weak key.
 */
int DES_set_key_checked(const_DES_cblock *key, DES_key_schedule *schedule)
{
    if (!DES_check_key_parity(key))
        return -1;
    if (DES_is_weak_key(key))
        return -2;
    DES_set_key_unchecked(key, schedule);
    return 0;
}

void DES_set_key_unchecked(const_DES_cblock *key, DES_key_schedule *schedule)
{
    static const int shifts2[16] =
        { 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0 };
    register DES_LONG c, d, t, s, t2;
    register const unsigned char *in;
    register DES_LONG *k;
    register int i;

#ifdef OPENBSD_DEV_CRYPTO
    memcpy(schedule->key, key, sizeof(schedule->key));
    schedule->session = NULL;
#endif
    k = &schedule->ks->deslong[0];
    in = &(*key)[0];

    c2l(in, c);
    c2l(in, d);

    /*
     * do PC1 in 47 simple operations. Thanks to John Fletcher
     * for the inspiration.
     */
    PERM_OP(d, c, t, 4, 0x0f0f0f0fL);
    HPERM_OP(c, t, -2, 0xcccc0000L);
    HPERM_OP(d, t, -2, 0xcccc0000L);
    PERM_OP(d, c, t, 1, 0x55555555L);
    PERM_OP(c, d, t, 8, 0x00ff00ffL);
    PERM_OP(d, c, t, 1, 0x55555555L);
    d = (((d & 0x000000ffL) << 16L) | (d & 0x0000ff00L) |
         ((d & 0x00ff0000L) >> 16L) | ((c & 0xf0000000L) >> 4L));
    c &= 0x0fffffffL;

    for (i = 0; i < ITERATIONS; i++) {
        if (shifts2[i]) {
            c = ((c >> 2L) | (c << 26L));
            d = ((d >> 2L) | (d << 26L));
        } else {
            c = ((c >> 1L) | (c << 27L));
            d = ((d >> 1L) | (d << 27L));
        }
        c &= 0x0fffffffL;
        d &= 0x0fffffffL;
        /*
         * could be a few less shifts but I am to lazy at this point in time
         * to investigate
         */
        s = des_skb[0][(c) & 0x3f] |
            des_skb[1][((c >> 6L) & 0x03) | ((c >> 7L) & 0x3c)] |
            des_skb[2][((c >> 13L) & 0x0f) | ((c >> 14L) & 0x30)] |
            des_skb[3][((c >> 20L) & 0x01) | ((c >> 21L) & 0x06) |
                       ((c >> 22L) & 0x38)];
        t = des_skb[4][(d) & 0x3f] |
            des_skb[5][((d >> 7L) & 0x03) | ((d >> 8L) & 0x3c)] |
            des_skb[6][(d >> 15L) & 0x3f] |
            des_skb[7][((d >> 21L) & 0x0f) | ((d >> 22L) & 0x30)];

        /* table contained 0213 4657 */
        t2 = ((t << 16L) | (s & 0x0000ffffL)) & 0xffffffffL;
        *(k++) = ROTATE(t2, 30) & 0xffffffffL;

        t2 = ((s >> 16L) | (t & 0xffff0000L));
        *(k++) = ROTATE(t2, 26) & 0xffffffffL;
    }
}

int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule)
{
    return DES_set_key(key, schedule);
}