sha1.c

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#include "includes.h"

#include "common.h"
#include "sha1.h"
#include "md5.h"
#include "crypto.h"


void hmac_sha1_vector(const u8 *key, size_t key_len, size_t num_elem,
                      const u8 *addr[], const size_t *len, u8 *mac)
{
        unsigned char k_pad[64]; /* padding - key XORd with ipad/opad */
        unsigned char tk[20];
        const u8 *_addr[6];
        size_t _len[6], i;

        if (num_elem > 5) {
                /*
                 * Fixed limit on the number of fragments to avoid having to
                 * allocate memory (which could fail).
                 */
                return;
        }

        /* if key is longer than 64 bytes reset it to key = SHA1(key) */
        if (key_len > 64) {
                sha1_vector(1, &key, &key_len, tk);
                key = tk;
                key_len = 20;
        }

        /* the HMAC_SHA1 transform looks like:
         *
         * SHA1(K XOR opad, SHA1(K XOR ipad, text))
         *
         * where K is an n byte key
         * ipad is the byte 0x36 repeated 64 times
         * opad is the byte 0x5c repeated 64 times
         * and text is the data being protected */

        /* start out by storing key in ipad */
        os_memset(k_pad, 0, sizeof(k_pad));
        os_memcpy(k_pad, key, key_len);
        /* XOR key with ipad values */
        for (i = 0; i < 64; i++)
                k_pad[i] ^= 0x36;

        /* perform inner SHA1 */
        _addr[0] = k_pad;
        _len[0] = 64;
        for (i = 0; i < num_elem; i++) {
                _addr[i + 1] = addr[i];
                _len[i + 1] = len[i];
        }
        sha1_vector(1 + num_elem, _addr, _len, mac);

        os_memset(k_pad, 0, sizeof(k_pad));
        os_memcpy(k_pad, key, key_len);
        /* XOR key with opad values */
        for (i = 0; i < 64; i++)
                k_pad[i] ^= 0x5c;

        /* perform outer SHA1 */
        _addr[0] = k_pad;
        _len[0] = 64;
        _addr[1] = mac;
        _len[1] = SHA1_MAC_LEN;
        sha1_vector(2, _addr, _len, mac);
}


void hmac_sha1(const u8 *key, size_t key_len, const u8 *data, size_t data_len,
               u8 *mac)
{
        hmac_sha1_vector(key, key_len, 1, &data, &data_len, mac);
}


void sha1_prf(const u8 *key, size_t key_len, const char *label,
              const u8 *data, size_t data_len, u8 *buf, size_t buf_len)
{
        u8 zero = 0, counter = 0;
        size_t pos, plen;
        u8 hash[SHA1_MAC_LEN];
        size_t label_len = os_strlen(label);
        const unsigned char *addr[4];
        size_t len[4];

        addr[0] = (u8 *) label;
        len[0] = label_len;
        addr[1] = &zero;
        len[1] = 1;
        addr[2] = data;
        len[2] = data_len;
        addr[3] = &counter;
        len[3] = 1;

        pos = 0;
        while (pos < buf_len) {
                plen = buf_len - pos;
                if (plen >= SHA1_MAC_LEN) {
                        hmac_sha1_vector(key, key_len, 4, addr, len,
                                         &buf[pos]);
                        pos += SHA1_MAC_LEN;
                } else {
                        hmac_sha1_vector(key, key_len, 4, addr, len,
                                         hash);
                        os_memcpy(&buf[pos], hash, plen);
                        break;
                }
                counter++;
        }
}


void sha1_t_prf(const u8 *key, size_t key_len, const char *label,
                const u8 *seed, size_t seed_len, u8 *buf, size_t buf_len)
{
        unsigned char counter = 0;
        size_t pos, plen;
        u8 hash[SHA1_MAC_LEN];
        size_t label_len = os_strlen(label);
        u8 output_len[2];
        const unsigned char *addr[5];
        size_t len[5];

        addr[0] = hash;
        len[0] = 0;
        addr[1] = (unsigned char *) label;
        len[1] = label_len + 1;
        addr[2] = seed;
        len[2] = seed_len;
        addr[3] = output_len;
        len[3] = 2;
        addr[4] = &counter;
        len[4] = 1;

        output_len[0] = (buf_len >> 8) & 0xff;
        output_len[1] = buf_len & 0xff;
        pos = 0;
        while (pos < buf_len) {
                counter++;
                plen = buf_len - pos;
                hmac_sha1_vector(key, key_len, 5, addr, len, hash);
                if (plen >= SHA1_MAC_LEN) {
                        os_memcpy(&buf[pos], hash, SHA1_MAC_LEN);
                        pos += SHA1_MAC_LEN;
                } else {
                        os_memcpy(&buf[pos], hash, plen);
                        break;
                }
                len[0] = SHA1_MAC_LEN;
        }
}


int tls_prf(const u8 *secret, size_t secret_len, const char *label,
            const u8 *seed, size_t seed_len, u8 *out, size_t outlen)
{
        size_t L_S1, L_S2, i;
        const u8 *S1, *S2;
        u8 A_MD5[MD5_MAC_LEN], A_SHA1[SHA1_MAC_LEN];
        u8 P_MD5[MD5_MAC_LEN], P_SHA1[SHA1_MAC_LEN];
        int MD5_pos, SHA1_pos;
        const u8 *MD5_addr[3];
        size_t MD5_len[3];
        const unsigned char *SHA1_addr[3];
        size_t SHA1_len[3];

        if (secret_len & 1)
                return -1;

        MD5_addr[0] = A_MD5;
        MD5_len[0] = MD5_MAC_LEN;
        MD5_addr[1] = (unsigned char *) label;
        MD5_len[1] = os_strlen(label);
        MD5_addr[2] = seed;
        MD5_len[2] = seed_len;

        SHA1_addr[0] = A_SHA1;
        SHA1_len[0] = SHA1_MAC_LEN;
        SHA1_addr[1] = (unsigned char *) label;
        SHA1_len[1] = os_strlen(label);
        SHA1_addr[2] = seed;
        SHA1_len[2] = seed_len;

        /* RFC 2246, Chapter 5
         * A(0) = seed, A(i) = HMAC(secret, A(i-1))
         * P_hash = HMAC(secret, A(1) + seed) + HMAC(secret, A(2) + seed) + ..
         * PRF = P_MD5(S1, label + seed) XOR P_SHA-1(S2, label + seed)
         */

        L_S1 = L_S2 = (secret_len + 1) / 2;
        S1 = secret;
        S2 = secret + L_S1;

        hmac_md5_vector(S1, L_S1, 2, &MD5_addr[1], &MD5_len[1], A_MD5);
        hmac_sha1_vector(S2, L_S2, 2, &SHA1_addr[1], &SHA1_len[1], A_SHA1);

        MD5_pos = MD5_MAC_LEN;
        SHA1_pos = SHA1_MAC_LEN;
        for (i = 0; i < outlen; i++) {
                if (MD5_pos == MD5_MAC_LEN) {
                        hmac_md5_vector(S1, L_S1, 3, MD5_addr, MD5_len, P_MD5);
                        MD5_pos = 0;
                        hmac_md5(S1, L_S1, A_MD5, MD5_MAC_LEN, A_MD5);
                }
                if (SHA1_pos == SHA1_MAC_LEN) {
                        hmac_sha1_vector(S2, L_S2, 3, SHA1_addr, SHA1_len,
                                         P_SHA1);
                        SHA1_pos = 0;
                        hmac_sha1(S2, L_S2, A_SHA1, SHA1_MAC_LEN, A_SHA1);
                }

                out[i] = P_MD5[MD5_pos] ^ P_SHA1[SHA1_pos];

                MD5_pos++;
                SHA1_pos++;
        }

        return 0;
}


static void pbkdf2_sha1_f(const char *passphrase, const char *ssid,
                          size_t ssid_len, int iterations, unsigned int count,
                          u8 *digest)
{
        unsigned char tmp[SHA1_MAC_LEN], tmp2[SHA1_MAC_LEN];
        int i, j;
        unsigned char count_buf[4];
        const u8 *addr[2];
        size_t len[2];
        size_t passphrase_len = os_strlen(passphrase);

        addr[0] = (u8 *) ssid;
        len[0] = ssid_len;
        addr[1] = count_buf;
        len[1] = 4;

        /* F(P, S, c, i) = U1 xor U2 xor ... Uc
         * U1 = PRF(P, S || i)
         * U2 = PRF(P, U1)
         * Uc = PRF(P, Uc-1)
         */

        count_buf[0] = (count >> 24) & 0xff;
        count_buf[1] = (count >> 16) & 0xff;
        count_buf[2] = (count >> 8) & 0xff;
        count_buf[3] = count & 0xff;
        hmac_sha1_vector((u8 *) passphrase, passphrase_len, 2, addr, len, tmp);
        os_memcpy(digest, tmp, SHA1_MAC_LEN);

        for (i = 1; i < iterations; i++) {
                hmac_sha1((u8 *) passphrase, passphrase_len, tmp, SHA1_MAC_LEN,
                          tmp2);
                os_memcpy(tmp, tmp2, SHA1_MAC_LEN);
                for (j = 0; j < SHA1_MAC_LEN; j++)
                        digest[j] ^= tmp2[j];
        }
}


void pbkdf2_sha1(const char *passphrase, const char *ssid, size_t ssid_len,
                 int iterations, u8 *buf, size_t buflen)
{
        unsigned int count = 0;
        unsigned char *pos = buf;
        size_t left = buflen, plen;
        unsigned char digest[SHA1_MAC_LEN];

        while (left > 0) {
                count++;
                pbkdf2_sha1_f(passphrase, ssid, ssid_len, iterations, count,
                              digest);
                plen = left > SHA1_MAC_LEN ? SHA1_MAC_LEN : left;
                os_memcpy(pos, digest, plen);
                pos += plen;
                left -= plen;
        }
}


#ifdef INTERNAL_SHA1

struct SHA1Context {
        u32 state[5];
        u32 count[2];
        unsigned char buffer[64];
};

typedef struct SHA1Context SHA1_CTX;

#ifndef CONFIG_CRYPTO_INTERNAL
static void SHA1Init(struct SHA1Context *context);
static void SHA1Update(struct SHA1Context *context, const void *data, u32 len);
static void SHA1Final(unsigned char digest[20], struct SHA1Context *context);
#endif /* CONFIG_CRYPTO_INTERNAL */
static void SHA1Transform(u32 state[5], const unsigned char buffer[64]);


void sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len,
                 u8 *mac)
{
        SHA1_CTX ctx;
        size_t i;

        SHA1Init(&ctx);
        for (i = 0; i < num_elem; i++)
                SHA1Update(&ctx, addr[i], len[i]);
        SHA1Final(mac, &ctx);
}


int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
{
        u8 xkey[64];
        u32 t[5], _t[5];
        int i, j, m, k;
        u8 *xpos = x;
        u32 carry;

        if (seed_len > sizeof(xkey))
                seed_len = sizeof(xkey);

        /* FIPS 186-2 + change notice 1 */

        os_memcpy(xkey, seed, seed_len);
        os_memset(xkey + seed_len, 0, 64 - seed_len);
        t[0] = 0x67452301;
        t[1] = 0xEFCDAB89;
        t[2] = 0x98BADCFE;
        t[3] = 0x10325476;
        t[4] = 0xC3D2E1F0;

        m = xlen / 40;
        for (j = 0; j < m; j++) {
                /* XSEED_j = 0 */
                for (i = 0; i < 2; i++) {
                        /* XVAL = (XKEY + XSEED_j) mod 2^b */

                        /* w_i = G(t, XVAL) */
                        os_memcpy(_t, t, 20);
                        SHA1Transform(_t, xkey);
                        _t[0] = host_to_be32(_t[0]);
                        _t[1] = host_to_be32(_t[1]);
                        _t[2] = host_to_be32(_t[2]);
                        _t[3] = host_to_be32(_t[3]);
                        _t[4] = host_to_be32(_t[4]);
                        os_memcpy(xpos, _t, 20);

                        /* XKEY = (1 + XKEY + w_i) mod 2^b */
                        carry = 1;
                        for (k = 19; k >= 0; k--) {
                                carry += xkey[k] + xpos[k];
                                xkey[k] = carry & 0xff;
                                carry >>= 8;
                        }

                        xpos += SHA1_MAC_LEN;
                }
                /* x_j = w_0|w_1 */
        }

        return 0;
}


/* ===== start - public domain SHA1 implementation ===== */

/*
SHA-1 in C
By Steve Reid <[email protected]>
100% Public Domain

-----------------
Modified 7/98 
By James H. Brown <[email protected]>
Still 100% Public Domain

Corrected a problem which generated improper hash values on 16 bit machines
Routine SHA1Update changed from
        void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int
len)
to
        void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned
long len)

The 'len' parameter was declared an int which works fine on 32 bit machines.
However, on 16 bit machines an int is too small for the shifts being done
against
it.  This caused the hash function to generate incorrect values if len was
greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update().

Since the file IO in main() reads 16K at a time, any file 8K or larger would
be guaranteed to generate the wrong hash (e.g. Test Vector #3, a million
"a"s).

I also changed the declaration of variables i & j in SHA1Update to 
unsigned long from unsigned int for the same reason.

These changes should make no difference to any 32 bit implementations since
an
int and a long are the same size in those environments.

--
I also corrected a few compiler warnings generated by Borland C.
1. Added #include <process.h> for exit() prototype
2. Removed unused variable 'j' in SHA1Final
3. Changed exit(0) to return(0) at end of main.

ALL changes I made can be located by searching for comments containing 'JHB'
-----------------
Modified 8/98
By Steve Reid <[email protected]>
Still 100% public domain

1- Removed #include <process.h> and used return() instead of exit()
2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)
3- Changed email address from [email protected] to [email protected]

-----------------
Modified 4/01
By Saul Kravitz <[email protected]>
Still 100% PD
Modified to run on Compaq Alpha hardware.  

-----------------
Modified 4/01
By Jouni Malinen <[email protected]>
Minor changes to match the coding style used in Dynamics.

Modified September 24, 2004
By Jouni Malinen <[email protected]>
Fixed alignment issue in SHA1Transform when SHA1HANDSOFF is defined.

*/

/*
Test Vectors (from FIPS PUB 180-1)
"abc"
  A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
  84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
A million repetitions of "a"
  34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
*/

#define SHA1HANDSOFF

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

/* blk0() and blk() perform the initial expand. */
/* I got the idea of expanding during the round function from SSLeay */
#ifndef WORDS_BIGENDIAN
#define blk0(i) (block->l[i] = (rol(block->l[i], 24) & 0xFF00FF00) | \
        (rol(block->l[i], 8) & 0x00FF00FF))
#else
#define blk0(i) block->l[i]
#endif
#define blk(i) (block->l[i & 15] = rol(block->l[(i + 13) & 15] ^ \
        block->l[(i + 8) & 15] ^ block->l[(i + 2) & 15] ^ block->l[i & 15], 1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) \
        z += ((w & (x ^ y)) ^ y) + blk0(i) + 0x5A827999 + rol(v, 5); \
        w = rol(w, 30);
#define R1(v,w,x,y,z,i) \
        z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
        w = rol(w, 30);
#define R2(v,w,x,y,z,i) \
        z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); w = rol(w, 30);
#define R3(v,w,x,y,z,i) \
        z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
        w = rol(w, 30);
#define R4(v,w,x,y,z,i) \
        z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
        w=rol(w, 30);


#ifdef VERBOSE  /* SAK */
void SHAPrintContext(SHA1_CTX *context, char *msg)
{
        printf("%s (%d,%d) %x %x %x %x %x\n",
               msg,
               context->count[0], context->count[1], 
               context->state[0],
               context->state[1],
               context->state[2],
               context->state[3],
               context->state[4]);
}
#endif

/* Hash a single 512-bit block. This is the core of the algorithm. */

static void SHA1Transform(u32 state[5], const unsigned char buffer[64])
{
        u32 a, b, c, d, e;
        typedef union {
                unsigned char c[64];
                u32 l[16];
        } CHAR64LONG16;
        CHAR64LONG16* block;
#ifdef SHA1HANDSOFF
        u32 workspace[16];
        block = (CHAR64LONG16 *) workspace;
        os_memcpy(block, buffer, 64);
#else
        block = (CHAR64LONG16 *) buffer;
#endif
        /* Copy context->state[] to working vars */
        a = state[0];
        b = state[1];
        c = state[2];
        d = state[3];
        e = state[4];
        /* 4 rounds of 20 operations each. Loop unrolled. */
        R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
        R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
        R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
        R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
        R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
        R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
        R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
        R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
        R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
        R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
        R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
        R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
        R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
        R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
        R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
        R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
        R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
        R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
        R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
        R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
        /* Add the working vars back into context.state[] */
        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;
        state[4] += e;
        /* Wipe variables */
        a = b = c = d = e = 0;
#ifdef SHA1HANDSOFF
        os_memset(block, 0, 64);
#endif
}


/* SHA1Init - Initialize new context */

void SHA1Init(SHA1_CTX* context)
{
        /* SHA1 initialization constants */
        context->state[0] = 0x67452301;
        context->state[1] = 0xEFCDAB89;
        context->state[2] = 0x98BADCFE;
        context->state[3] = 0x10325476;
        context->state[4] = 0xC3D2E1F0;
        context->count[0] = context->count[1] = 0;
}


/* Run your data through this. */

void SHA1Update(SHA1_CTX* context, const void *_data, u32 len)
{
        u32 i, j;
        const unsigned char *data = _data;

#ifdef VERBOSE
        SHAPrintContext(context, "before");
#endif
        j = (context->count[0] >> 3) & 63;
        if ((context->count[0] += len << 3) < (len << 3))
                context->count[1]++;
        context->count[1] += (len >> 29);
        if ((j + len) > 63) {
                os_memcpy(&context->buffer[j], data, (i = 64-j));
                SHA1Transform(context->state, context->buffer);
                for ( ; i + 63 < len; i += 64) {
                        SHA1Transform(context->state, &data[i]);
                }
                j = 0;
        }
        else i = 0;
        os_memcpy(&context->buffer[j], &data[i], len - i);
#ifdef VERBOSE
        SHAPrintContext(context, "after ");
#endif
}


/* Add padding and return the message digest. */

void SHA1Final(unsigned char digest[20], SHA1_CTX* context)
{
        u32 i;
        unsigned char finalcount[8];

        for (i = 0; i < 8; i++) {
                finalcount[i] = (unsigned char)
                        ((context->count[(i >= 4 ? 0 : 1)] >>
                          ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
        }
        SHA1Update(context, (unsigned char *) "\200", 1);
        while ((context->count[0] & 504) != 448) {
                SHA1Update(context, (unsigned char *) "\0", 1);
        }
        SHA1Update(context, finalcount, 8);  /* Should cause a SHA1Transform()
                                              */
        for (i = 0; i < 20; i++) {
                digest[i] = (unsigned char)
                        ((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) &
                         255);
        }
        /* Wipe variables */
        i = 0;
        os_memset(context->buffer, 0, 64);
        os_memset(context->state, 0, 20);
        os_memset(context->count, 0, 8);
        os_memset(finalcount, 0, 8);
}

/* ===== end - public domain SHA1 implementation ===== */

#endif /* INTERNAL_SHA1 */

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