C++ CHECK_MPI_OK函数代码示例

/*
** An attack against RSA CRT was described by Boneh, DeMillo, and Lipton in:
** "On the Importance of Eliminating Errors in Cryptographic Computations",
** http://theory.stanford.edu/~dabo/papers/faults.ps.gz
**
** As a defense against the attack, carry out the private key operation, 
** followed up with a public key operation to invert the result.  
** Verify that result against the input.
*/
static SECStatus 
rsa_PrivateKeyOpCRTCheckedPubKey(RSAPrivateKey *key, mp_int *m, mp_int *c)
{
    mp_int n, e, v;
    mp_err   err = MP_OKAY;
    SECStatus rv = SECSuccess;
    MP_DIGITS(&n) = 0;
    MP_DIGITS(&e) = 0;
    MP_DIGITS(&v) = 0;
    CHECK_MPI_OK( mp_init(&n) );
    CHECK_MPI_OK( mp_init(&e) );
    CHECK_MPI_OK( mp_init(&v) );
    CHECK_SEC_OK( rsa_PrivateKeyOpCRTNoCheck(key, m, c) );
    SECITEM_TO_MPINT(key->modulus,        &n);
    SECITEM_TO_MPINT(key->publicExponent, &e);
    /* Perform a public key operation v = m ** e mod n */
    CHECK_MPI_OK( mp_exptmod(m, &e, &n, &v) );
    if (mp_cmp(&v, c) != 0) {
	rv = SECFailure;
    }
cleanup:
    mp_clear(&n);
    mp_clear(&e);
    mp_clear(&v);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

/* Generate a random private key using the algorithm A.4.1 of ANSI X9.62,
 * modified a la FIPS 186-2 Change Notice 1 to eliminate the bias in the
 * random number generator.
 *
 * Parameters
 * - order: a buffer that holds the curve's group order
 * - len: the length in octets of the order buffer
 * - random: a buffer of 2 * len random bytes
 * - randomlen: the length in octets of the random buffer
 *
 * Return Value
 * Returns a buffer of len octets that holds the private key. The caller
 * is responsible for freeing the buffer with PORT_ZFree.
 */
static unsigned char *
ec_GenerateRandomPrivateKey(const unsigned char *order, int len,
    const unsigned char *random, int randomlen, int kmflag)
{
    SECStatus rv = SECSuccess;
    mp_err err;
    unsigned char *privKeyBytes = NULL;
    mp_int privKeyVal, order_1, one;

    MP_DIGITS(&privKeyVal) = 0;
    MP_DIGITS(&order_1) = 0;
    MP_DIGITS(&one) = 0;
    CHECK_MPI_OK( mp_init(&privKeyVal, kmflag) );
    CHECK_MPI_OK( mp_init(&order_1, kmflag) );
    CHECK_MPI_OK( mp_init(&one, kmflag) );

    /*
     * Reduces the 2*len buffer of random bytes modulo the group order.
     */
    if ((privKeyBytes = PORT_Alloc(2*len, kmflag)) == NULL) goto cleanup;
    if (randomlen != 2 * len) {
        randomlen = 2 * len;
    }
    /* No need to generate - random bytes are now supplied */
    /* CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(privKeyBytes, 2*len) );*/
    memcpy(privKeyBytes, random, randomlen);

    CHECK_MPI_OK( mp_read_unsigned_octets(&privKeyVal, privKeyBytes, 2*len) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&order_1, order, len) );
    CHECK_MPI_OK( mp_set_int(&one, 1) );
    CHECK_MPI_OK( mp_sub(&order_1, &one, &order_1) );
    CHECK_MPI_OK( mp_mod(&privKeyVal, &order_1, &privKeyVal) );
    CHECK_MPI_OK( mp_add(&privKeyVal, &one, &privKeyVal) );
    CHECK_MPI_OK( mp_to_fixlen_octets(&privKeyVal, privKeyBytes, len) );
    memset(privKeyBytes+len, 0, len);
cleanup:
    mp_clear(&privKeyVal);
    mp_clear(&order_1);
    mp_clear(&one);
    if (err < MP_OKAY) {
        MP_TO_SEC_ERROR(err);
        rv = SECFailure;
    }
    if (rv != SECSuccess && privKeyBytes) {
#ifdef _KERNEL
        kmem_free(privKeyBytes, 2*len);
#else
        free(privKeyBytes);
#endif
        privKeyBytes = NULL;
    }
    return privKeyBytes;
}

static SECStatus
generate_prime(mp_int *prime, int primeLen)
{
    mp_err   err = MP_OKAY;
    SECStatus rv = SECSuccess;
    unsigned long counter = 0;
    int piter;
    unsigned char *pb = NULL;
    pb = PORT_Alloc(primeLen);
    if (!pb) {
	PORT_SetError(SEC_ERROR_NO_MEMORY);
	goto cleanup;
    }
    for (piter = 0; piter < MAX_PRIME_GEN_ATTEMPTS; piter++) {
	CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(pb, primeLen) );
	pb[0]          |= 0xC0; /* set two high-order bits */
	pb[primeLen-1] |= 0x01; /* set low-order bit       */
	CHECK_MPI_OK( mp_read_unsigned_octets(prime, pb, primeLen) );
	err = mpp_make_prime(prime, primeLen * 8, PR_FALSE, &counter);
	if (err != MP_NO)
	    goto cleanup;
	/* keep going while err == MP_NO */
    }
cleanup:
    if (pb)
	PORT_ZFree(pb, primeLen);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

/* Generate a random private key using the algorithm A.4.1 of ANSI X9.62,
 * modified a la FIPS 186-2 Change Notice 1 to eliminate the bias in the
 * random number generator.
 *
 * Parameters
 * - order: a buffer that holds the curve's group order
 * - len: the length in octets of the order buffer
 *
 * Return Value
 * Returns a buffer of len octets that holds the private key. The caller
 * is responsible for freeing the buffer with PORT_ZFree.
 */
static unsigned char *
ec_GenerateRandomPrivateKey(const unsigned char *order, int len, int kmflag)
{
    SECStatus rv = SECSuccess;
    mp_err err;
    unsigned char *privKeyBytes = NULL;
    mp_int privKeyVal, order_1, one;

    MP_DIGITS(&privKeyVal) = 0;
    MP_DIGITS(&order_1) = 0;
    MP_DIGITS(&one) = 0;
    CHECK_MPI_OK( mp_init(&privKeyVal) );
    CHECK_MPI_OK( mp_init(&order_1) );
    CHECK_MPI_OK( mp_init(&one) );

    /* Generates 2*len random bytes using the global random bit generator
     * (which implements Algorithm 1 of FIPS 186-2 Change Notice 1) then
     * reduces modulo the group order.
     */
    if ((privKeyBytes = PORT_Alloc(2*len, kmflag)) == NULL) goto cleanup;
    CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(privKeyBytes, 2*len) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&privKeyVal, privKeyBytes, 2*len) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&order_1, order, len) );
    CHECK_MPI_OK( mp_set_int(&one, 1) );
    CHECK_MPI_OK( mp_sub(&order_1, &one, &order_1) );
    CHECK_MPI_OK( mp_mod(&privKeyVal, &order_1, &privKeyVal) );
    CHECK_MPI_OK( mp_add(&privKeyVal, &one, &privKeyVal) );
    CHECK_MPI_OK( mp_to_fixlen_octets(&privKeyVal, privKeyBytes, len) );
    memset(privKeyBytes+len, 0, len);
cleanup:
    mp_clear(&privKeyVal);
    mp_clear(&order_1);
    mp_clear(&one);
    if (err < MP_OKAY) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    if (rv != SECSuccess && privKeyBytes) {
#ifdef _KERNEL
	kmem_free(privKeyBytes, 2*len);
#else
	free(privKeyBytes);
#endif
	privKeyBytes = NULL;
    }
    return privKeyBytes;
}

/*
**  RSA Private key operation (no CRT).
*/
static SECStatus 
rsa_PrivateKeyOpNoCRT(RSAPrivateKey *key, mp_int *m, mp_int *c, mp_int *n,
                      unsigned int modLen)
{
    mp_int d;
    mp_err   err = MP_OKAY;
    SECStatus rv = SECSuccess;
    MP_DIGITS(&d) = 0;
    CHECK_MPI_OK( mp_init(&d) );
    SECITEM_TO_MPINT(key->privateExponent, &d);
    /* 1. m = c**d mod n */
    CHECK_MPI_OK( mp_exptmod(c, &d, n, m) );
cleanup:
    mp_clear(&d);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

static SECStatus
init_blinding_params(struct RSABlindingParamsStr *rsabp, RSAPrivateKey *key,
                     mp_int *n, unsigned int modLen)
{
    SECStatus rv = SECSuccess;
    mp_err err = MP_OKAY;
    MP_DIGITS(&rsabp->f) = 0;
    MP_DIGITS(&rsabp->g) = 0;
    /* initialize blinding parameters */
    CHECK_MPI_OK( mp_init(&rsabp->f) );
    CHECK_MPI_OK( mp_init(&rsabp->g) );
    /* List elements are keyed using the modulus */
    SECITEM_CopyItem(NULL, &rsabp->modulus, &key->modulus);
    CHECK_SEC_OK( generate_blinding_params(rsabp, key, n, modLen) );
    return SECSuccess;
cleanup:
    mp_clear(&rsabp->f);
    mp_clear(&rsabp->g);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

PRBool 
KEA_Verify(SECItem *Y, SECItem *prime, SECItem *subPrime)
{
    mp_int p, q, y, r;
    mp_err err;
    int cmp = 1;  /* default is false */
    if (!Y || !prime || !subPrime) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }
    MP_DIGITS(&p) = 0;
    MP_DIGITS(&q) = 0;
    MP_DIGITS(&y) = 0;
    MP_DIGITS(&r) = 0;
    CHECK_MPI_OK( mp_init(&p) );
    CHECK_MPI_OK( mp_init(&q) );
    CHECK_MPI_OK( mp_init(&y) );
    CHECK_MPI_OK( mp_init(&r) );
    SECITEM_TO_MPINT(*prime,    &p);
    SECITEM_TO_MPINT(*subPrime, &q);
    SECITEM_TO_MPINT(*Y,        &y);
    /* compute r = y**q mod p */
    CHECK_MPI_OK( mp_exptmod(&y, &q, &p, &r) );
    /* compare to 1 */
    cmp = mp_cmp_d(&r, 1);
cleanup:
    mp_clear(&p);
    mp_clear(&q);
    mp_clear(&y);
    mp_clear(&r);
    if (err) {
	MP_TO_SEC_ERROR(err);
	return PR_FALSE;
    }
    return (cmp == 0) ? PR_TRUE : PR_FALSE;
}

/*
 * FIPS 186-2 requires result from random output to be reduced mod q when 
 * generating random numbers for DSA. 
 *
 * Input: w, 2*qLen bytes
 *        q, qLen bytes
 * Output: xj, qLen bytes
 */
static SECStatus
fips186Change_ReduceModQForDSA(const PRUint8 *w, const PRUint8 *q,
                               unsigned int qLen, PRUint8 * xj)
{
    mp_int W, Q, Xj;
    mp_err err;
    SECStatus rv = SECSuccess;

    /* Initialize MPI integers. */
    MP_DIGITS(&W) = 0;
    MP_DIGITS(&Q) = 0;
    MP_DIGITS(&Xj) = 0;
    CHECK_MPI_OK( mp_init(&W) );
    CHECK_MPI_OK( mp_init(&Q) );
    CHECK_MPI_OK( mp_init(&Xj) );
    /*
     * Convert input arguments into MPI integers.
     */
    CHECK_MPI_OK( mp_read_unsigned_octets(&W, w, 2*qLen) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&Q, q, qLen) );

    /*
     * Algorithm 1 of FIPS 186-2 Change Notice 1, Step 3.3
     *
     * xj = (w0 || w1) mod q
     */
    CHECK_MPI_OK( mp_mod(&W, &Q, &Xj) );
    CHECK_MPI_OK( mp_to_fixlen_octets(&Xj, xj, qLen) );
cleanup:
    mp_clear(&W);
    mp_clear(&Q);
    mp_clear(&Xj);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

static SECStatus
generate_blinding_params(struct RSABlindingParamsStr *rsabp, 
                         RSAPrivateKey *key, mp_int *n, unsigned int modLen)
{
    SECStatus rv = SECSuccess;
    mp_int e, k;
    mp_err err = MP_OKAY;
    unsigned char *kb = NULL;
    MP_DIGITS(&e) = 0;
    MP_DIGITS(&k) = 0;
    CHECK_MPI_OK( mp_init(&e) );
    CHECK_MPI_OK( mp_init(&k) );
    SECITEM_TO_MPINT(key->publicExponent, &e);
    /* generate random k < n */
    kb = PORT_Alloc(modLen);
    if (!kb) {
	PORT_SetError(SEC_ERROR_NO_MEMORY);
	goto cleanup;
    }
    CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(kb, modLen) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&k, kb, modLen) );
    /* k < n */
    CHECK_MPI_OK( mp_mod(&k, n, &k) );
    /* f = k**e mod n */
    CHECK_MPI_OK( mp_exptmod(&k, &e, n, &rsabp->f) );
    /* g = k**-1 mod n */
    CHECK_MPI_OK( mp_invmod(&k, n, &rsabp->g) );
    /* Initialize the counter for this (f, g) */
    rsabp->counter = RSA_BLINDING_PARAMS_MAX_REUSE;
cleanup:
    if (kb)
	PORT_ZFree(kb, modLen);
    mp_clear(&k);
    mp_clear(&e);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

static SECStatus
generate_blinding_params(RSAPrivateKey *key, mp_int* f, mp_int* g, mp_int *n, 
                         unsigned int modLen)
{
    SECStatus rv = SECSuccess;
    mp_int e, k;
    mp_err err = MP_OKAY;
    unsigned char *kb = NULL;

    MP_DIGITS(&e) = 0;
    MP_DIGITS(&k) = 0;
    CHECK_MPI_OK( mp_init(&e) );
    CHECK_MPI_OK( mp_init(&k) );
    SECITEM_TO_MPINT(key->publicExponent, &e);
    /* generate random k < n */
    kb = PORT_Alloc(modLen);
    if (!kb) {
	PORT_SetError(SEC_ERROR_NO_MEMORY);
	goto cleanup;
    }
    CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(kb, modLen) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&k, kb, modLen) );
    /* k < n */
    CHECK_MPI_OK( mp_mod(&k, n, &k) );
    /* f = k**e mod n */
    CHECK_MPI_OK( mp_exptmod(&k, &e, n, f) );
    /* g = k**-1 mod n */
    CHECK_MPI_OK( mp_invmod(&k, n, g) );
cleanup:
    if (kb)
	PORT_ZFree(kb, modLen);
    mp_clear(&k);
    mp_clear(&e);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}

SECStatus 
DH_GenParam(int primeLen, DHParams **params)
{
    PLArenaPool *arena;
    DHParams *dhparams;
    unsigned char *pb = NULL;
    unsigned char *ab = NULL;
    unsigned long counter = 0;
    mp_int p, q, a, h, psub1, test;
    mp_err err = MP_OKAY;
    SECStatus rv = SECSuccess;
    if (!params || primeLen < 0) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }
    arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
    if (!arena) {
	PORT_SetError(SEC_ERROR_NO_MEMORY);
	return SECFailure;
    }
    dhparams = (DHParams *)PORT_ArenaZAlloc(arena, sizeof(DHParams));
    if (!dhparams) {
	PORT_SetError(SEC_ERROR_NO_MEMORY);
	PORT_FreeArena(arena, PR_TRUE);
	return SECFailure;
    }
    dhparams->arena = arena;
    MP_DIGITS(&p) = 0;
    MP_DIGITS(&q) = 0;
    MP_DIGITS(&a) = 0;
    MP_DIGITS(&h) = 0;
    MP_DIGITS(&psub1) = 0;
    MP_DIGITS(&test) = 0;
    CHECK_MPI_OK( mp_init(&p) );
    CHECK_MPI_OK( mp_init(&q) );
    CHECK_MPI_OK( mp_init(&a) );
    CHECK_MPI_OK( mp_init(&h) );
    CHECK_MPI_OK( mp_init(&psub1) );
    CHECK_MPI_OK( mp_init(&test) );
    /* generate prime with MPI, uses Miller-Rabin to generate strong prime. */
    pb = PORT_Alloc(primeLen);
    CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(pb, primeLen) );
    pb[0]          |= 0x80; /* set high-order bit */
    pb[primeLen-1] |= 0x01; /* set low-order bit  */
    CHECK_MPI_OK( mp_read_unsigned_octets(&p, pb, primeLen) );
    CHECK_MPI_OK( mpp_make_prime(&p, primeLen * 8, PR_TRUE, &counter) );
    /* construct Sophie-Germain prime q = (p-1)/2. */
    CHECK_MPI_OK( mp_sub_d(&p, 1, &psub1) );
    CHECK_MPI_OK( mp_div_2(&psub1, &q)    );
    /* construct a generator from the prime. */
    ab = PORT_Alloc(primeLen);
    /* generate a candidate number a in p's field */
    CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(ab, primeLen) );
    CHECK_MPI_OK( mp_read_unsigned_octets(&a, ab, primeLen) );
    /* force a < p (note that quot(a/p) <= 1) */
    if ( mp_cmp(&a, &p) > 0 )
	CHECK_MPI_OK( mp_sub(&a, &p, &a) );
    do {
	/* check that a is in the range [2..p-1] */
	if ( mp_cmp_d(&a, 2) < 0 || mp_cmp(&a, &psub1) >= 0) {
	    /* a is outside of the allowed range.  Set a=3 and keep going. */
            mp_set(&a, 3);
	}
	/* if a**q mod p != 1 then a is a generator */
	CHECK_MPI_OK( mp_exptmod(&a, &q, &p, &test) );
	if ( mp_cmp_d(&test, 1) != 0 )
	    break;
	/* increment the candidate and try again. */
	CHECK_MPI_OK( mp_add_d(&a, 1, &a) );
    } while (PR_TRUE);
    MPINT_TO_SECITEM(&p, &dhparams->prime, arena);
    MPINT_TO_SECITEM(&a, &dhparams->base, arena);
    *params = dhparams;
cleanup:
    mp_clear(&p);
    mp_clear(&q);
    mp_clear(&a);
    mp_clear(&h);
    mp_clear(&psub1);
    mp_clear(&test);
    if (pb) PORT_ZFree(pb, primeLen);
    if (ab) PORT_ZFree(ab, primeLen);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    if (rv)
	PORT_FreeArena(arena, PR_TRUE);
    return rv;
}

/* signature is caller-supplied buffer of at least 20 bytes.
** On input,  signature->len == size of buffer to hold signature.
**            digest->len    == size of digest.
*/
SECStatus 
DSA_VerifyDigest(DSAPublicKey *key, const SECItem *signature, 
                 const SECItem *digest)
{
    /* FIPS-compliance dictates that digest is a SHA hash. */
    mp_int p, q, g;      /* PQG parameters */
    mp_int r_, s_;       /* tuple (r', s') is received signature) */
    mp_int u1, u2, v, w; /* intermediate values used in verification */
    mp_int y;            /* public key */
    mp_err err;
    int dsa_subprime_len, dsa_signature_len, offset;
    SECItem localDigest;
    unsigned char localDigestData[DSA_MAX_SUBPRIME_LEN];
    SECStatus verified = SECFailure;

    /* Check args. */
    if (!key || !signature || !digest ) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }

    dsa_subprime_len = PQG_GetLength(&key->params.subPrime);
    dsa_signature_len = dsa_subprime_len*2;
    if ((signature->len != dsa_signature_len) ||
	(digest->len > HASH_LENGTH_MAX)  ||
	(digest->len < SHA1_LENGTH)) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }

    /* DSA accepts digests not equal to dsa_subprime_len, if the 
     * digests are greater, than they are truncated to the size of 
     * dsa_subprime_len, using the left most bits. If they are less
     * then they are padded on the left.*/
    PORT_Memset(localDigestData, 0, dsa_subprime_len);
    offset = (digest->len < dsa_subprime_len) ? 
			(dsa_subprime_len - digest->len) : 0;
    PORT_Memcpy(localDigestData+offset, digest->data, 
		dsa_subprime_len - offset);
    localDigest.data = localDigestData;
    localDigest.len = dsa_subprime_len;

    /* Initialize MPI integers. */
    MP_DIGITS(&p)  = 0;
    MP_DIGITS(&q)  = 0;
    MP_DIGITS(&g)  = 0;
    MP_DIGITS(&y)  = 0;
    MP_DIGITS(&r_) = 0;
    MP_DIGITS(&s_) = 0;
    MP_DIGITS(&u1) = 0;
    MP_DIGITS(&u2) = 0;
    MP_DIGITS(&v)  = 0;
    MP_DIGITS(&w)  = 0;
    CHECK_MPI_OK( mp_init(&p)  );
    CHECK_MPI_OK( mp_init(&q)  );
    CHECK_MPI_OK( mp_init(&g)  );
    CHECK_MPI_OK( mp_init(&y)  );
    CHECK_MPI_OK( mp_init(&r_) );
    CHECK_MPI_OK( mp_init(&s_) );
    CHECK_MPI_OK( mp_init(&u1) );
    CHECK_MPI_OK( mp_init(&u2) );
    CHECK_MPI_OK( mp_init(&v)  );
    CHECK_MPI_OK( mp_init(&w)  );
    /*
    ** Convert stored PQG and public key into MPI integers.
    */
    SECITEM_TO_MPINT(key->params.prime,    &p);
    SECITEM_TO_MPINT(key->params.subPrime, &q);
    SECITEM_TO_MPINT(key->params.base,     &g);
    SECITEM_TO_MPINT(key->publicValue,     &y);
    /*
    ** Convert received signature (r', s') into MPI integers.
    */
    OCTETS_TO_MPINT(signature->data, &r_, dsa_subprime_len);
    OCTETS_TO_MPINT(signature->data + dsa_subprime_len, &s_, dsa_subprime_len);
    /*
    ** Verify that 0 < r' < q and 0 < s' < q
    */
    if (mp_cmp_z(&r_) <= 0 || mp_cmp_z(&s_) <= 0 ||
        mp_cmp(&r_, &q) >= 0 || mp_cmp(&s_, &q) >= 0) {
	/* err is zero here. */
	PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
	goto cleanup; /* will return verified == SECFailure */
    }
    /*
    ** FIPS 186-1, Section 6, Step 1
    **
    ** w = (s')**-1 mod q
    */
    CHECK_MPI_OK( mp_invmod(&s_, &q, &w) );      /* w = (s')**-1 mod q */
    /*
    ** FIPS 186-1, Section 6, Step 2
    **
    ** u1 = ((Hash(M')) * w) mod q
    */
    SECITEM_TO_MPINT(localDigest, &u1);              /* u1 = HASH(M')     */
//.........这里部分代码省略.........

SECStatus 
KEA_Derive(SECItem *prime, 
           SECItem *public1, 
           SECItem *public2, 
           SECItem *private1, 
           SECItem *private2,
           SECItem *derivedSecret)
{
    mp_int p, Y, R, r, x, t, u, w;
    mp_err err;
    unsigned char *secret = NULL;
    unsigned int len = 0, offset;
    if (!prime || !public1 || !public2 || !private1 || !private2 ||
        !derivedSecret) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }
    memset(derivedSecret, 0, sizeof *derivedSecret);
    MP_DIGITS(&p) = 0;
    MP_DIGITS(&Y) = 0;
    MP_DIGITS(&R) = 0;
    MP_DIGITS(&r) = 0;
    MP_DIGITS(&x) = 0;
    MP_DIGITS(&t) = 0;
    MP_DIGITS(&u) = 0;
    MP_DIGITS(&w) = 0;
    CHECK_MPI_OK( mp_init(&p) );
    CHECK_MPI_OK( mp_init(&Y) );
    CHECK_MPI_OK( mp_init(&R) );
    CHECK_MPI_OK( mp_init(&r) );
    CHECK_MPI_OK( mp_init(&x) );
    CHECK_MPI_OK( mp_init(&t) );
    CHECK_MPI_OK( mp_init(&u) );
    CHECK_MPI_OK( mp_init(&w) );
    SECITEM_TO_MPINT(*prime,    &p);
    SECITEM_TO_MPINT(*public1,  &Y);
    SECITEM_TO_MPINT(*public2,  &R);
    SECITEM_TO_MPINT(*private1, &r);
    SECITEM_TO_MPINT(*private2, &x);
    /* t = DH(Y, r, p) = Y ** r mod p */
    CHECK_MPI_OK( mp_exptmod(&Y, &r, &p, &t) );
    /* u = DH(R, x, p) = R ** x mod p */
    CHECK_MPI_OK( mp_exptmod(&R, &x, &p, &u) );
    /* w = (t + u) mod p */
    CHECK_MPI_OK( mp_addmod(&t, &u, &p, &w) );
    /* allocate a buffer for the full derived secret */
    len = mp_unsigned_octet_size(&w);
    secret = PORT_Alloc(len);
    if (secret == NULL) {
	err = MP_MEM;
	goto cleanup;
    }
    /* grab the secret */
    err = mp_to_unsigned_octets(&w, secret, len);
    if (err > 0) err = MP_OKAY;
    /* allocate output buffer */
    if (SECITEM_AllocItem(NULL, derivedSecret, KEA_DERIVED_SECRET_LEN)
								  == NULL) {
	err = MP_MEM;
	goto cleanup;
    }
    memset(derivedSecret->data, 0, derivedSecret->len);
    /* copy in the 128 lsb of the secret */
    if (len >= KEA_DERIVED_SECRET_LEN) {
	memcpy(derivedSecret->data, secret + (len - KEA_DERIVED_SECRET_LEN),
	       KEA_DERIVED_SECRET_LEN);
    } else {
	offset = KEA_DERIVED_SECRET_LEN - len;
	memcpy(derivedSecret->data + offset, secret, len);
    }
cleanup:
    mp_clear(&p);
    mp_clear(&Y);
    mp_clear(&R);
    mp_clear(&r);
    mp_clear(&x);
    mp_clear(&t);
    mp_clear(&u);
    mp_clear(&w);
    if (secret)
	PORT_ZFree(secret, len);
    if (err) {
	MP_TO_SEC_ERROR(err);
	if (derivedSecret->data) 
	    PORT_ZFree(derivedSecret->data, derivedSecret->len);
	return SECFailure;
    }
    return SECSuccess;
}

SECStatus 
DH_Derive(SECItem *publicValue, 
          SECItem *prime, 
          SECItem *privateValue, 
          SECItem *derivedSecret, 
          unsigned int outBytes)
{
    mp_int p, Xa, Yb, ZZ, psub1;
    mp_err err = MP_OKAY;
    unsigned int len = 0;
    unsigned int nb;
    unsigned char *secret = NULL;
    if (!publicValue || !prime || !privateValue || !derivedSecret) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }
    memset(derivedSecret, 0, sizeof *derivedSecret);
    MP_DIGITS(&p)  = 0;
    MP_DIGITS(&Xa) = 0;
    MP_DIGITS(&Yb) = 0;
    MP_DIGITS(&ZZ) = 0;
    MP_DIGITS(&psub1) = 0;
    CHECK_MPI_OK( mp_init(&p)  );
    CHECK_MPI_OK( mp_init(&Xa) );
    CHECK_MPI_OK( mp_init(&Yb) );
    CHECK_MPI_OK( mp_init(&ZZ) );
    CHECK_MPI_OK( mp_init(&psub1) );
    SECITEM_TO_MPINT(*publicValue,  &Yb);
    SECITEM_TO_MPINT(*privateValue, &Xa);
    SECITEM_TO_MPINT(*prime,        &p);
    CHECK_MPI_OK( mp_sub_d(&p, 1, &psub1) );

    /* We assume that the modulus, p, is a safe prime. That is, p = 2q+1 where
     * q is also a prime. Thus the orders of the subgroups are factors of 2q:
     * namely 1, 2, q and 2q.
     *
     * We check that the peer's public value isn't zero (which isn't in the
     * group), one (subgroup of order one) or p-1 (subgroup of order 2). We
     * also check that the public value is less than p, to avoid being fooled
     * by values like p+1 or 2*p-1.
     *
     * Thus we must be operating in the subgroup of size q or 2q. */
    if (mp_cmp_d(&Yb, 1) <= 0 ||
	mp_cmp(&Yb, &psub1) >= 0) {
	err = MP_BADARG;
	goto cleanup;
    }

    /* ZZ = (Yb)**Xa mod p */
    CHECK_MPI_OK( mp_exptmod(&Yb, &Xa, &p, &ZZ) );
    /* number of bytes in the derived secret */
    len = mp_unsigned_octet_size(&ZZ);
    if (len <= 0) {
        err = MP_BADARG;
        goto cleanup;
    }

    /*
     * We check to make sure that ZZ is not equal to 1 or -1 mod p.
     * This helps guard against small subgroup attacks, since an attacker
     * using a subgroup of size N will produce 1 or -1 with probability 1/N.
     * When the protocol is executed within a properly large subgroup, the
     * probability of this result will be negligibly small.  For example,
     * with a strong prime of the form 2p+1, the probability will be 1/p.
     *
     * We return MP_BADARG because this is probably the result of a bad
     * public value or a bad prime having been provided.
     */
    if (mp_cmp_d(&ZZ, 1) == 0 ||
        mp_cmp(&ZZ, &psub1) == 0) {
        err = MP_BADARG;
        goto cleanup;
    }

    /* allocate a buffer which can hold the entire derived secret. */
    secret = PORT_Alloc(len);
    if (secret == NULL) {
	err = MP_MEM;
	goto cleanup;
    }
    /* grab the derived secret */
    err = mp_to_unsigned_octets(&ZZ, secret, len);
    if (err >= 0) err = MP_OKAY;
    /* 
    ** if outBytes is 0 take all of the bytes from the derived secret.
    ** if outBytes is not 0 take exactly outBytes from the derived secret, zero
    ** pad at the beginning if necessary, and truncate beginning bytes 
    ** if necessary.
    */
    if (outBytes > 0)
	nb = outBytes;
    else
	nb = len;
    if (SECITEM_AllocItem(NULL, derivedSecret, nb)  == NULL) {
	err = MP_MEM;
	goto cleanup;
    }
    if (len < nb) {
	unsigned int offset = nb - len;
	memset(derivedSecret->data, 0, offset);
//.........这里部分代码省略.........

/*
** Perform a raw private-key operation 
**	Length of input and output buffers are equal to key's modulus len.
*/
static SECStatus 
rsa_PrivateKeyOp(RSAPrivateKey *key, 
                 unsigned char *output, 
                 const unsigned char *input,
                 PRBool check)
{
    unsigned int modLen;
    unsigned int offset;
    SECStatus rv = SECSuccess;
    mp_err err;
    mp_int n, c, m;
    mp_int f, g;
    if (!key || !output || !input) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }
    /* check input out of range (needs to be in range [0..n-1]) */
    modLen = rsa_modulusLen(&key->modulus);
    offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */
    if (memcmp(input, key->modulus.data + offset, modLen) >= 0) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return SECFailure;
    }
    MP_DIGITS(&n) = 0;
    MP_DIGITS(&c) = 0;
    MP_DIGITS(&m) = 0;
    MP_DIGITS(&f) = 0;
    MP_DIGITS(&g) = 0;
    CHECK_MPI_OK( mp_init(&n) );
    CHECK_MPI_OK( mp_init(&c) );
    CHECK_MPI_OK( mp_init(&m) );
    CHECK_MPI_OK( mp_init(&f) );
    CHECK_MPI_OK( mp_init(&g) );
    SECITEM_TO_MPINT(key->modulus, &n);
    OCTETS_TO_MPINT(input, &c, modLen);
    /* If blinding, compute pre-image of ciphertext by multiplying by
    ** blinding factor
    */
    if (nssRSAUseBlinding) {
	CHECK_SEC_OK( get_blinding_params(key, &n, modLen, &f, &g) );
	/* c' = c*f mod n */
	CHECK_MPI_OK( mp_mulmod(&c, &f, &n, &c) );
    }
    /* Do the private key operation m = c**d mod n */
    if ( key->prime1.len      == 0 ||
         key->prime2.len      == 0 ||
         key->exponent1.len   == 0 ||
         key->exponent2.len   == 0 ||
         key->coefficient.len == 0) {
	CHECK_SEC_OK( rsa_PrivateKeyOpNoCRT(key, &m, &c, &n, modLen) );
    } else if (check) {
	CHECK_SEC_OK( rsa_PrivateKeyOpCRTCheckedPubKey(key, &m, &c) );
    } else {
	CHECK_SEC_OK( rsa_PrivateKeyOpCRTNoCheck(key, &m, &c) );
    }
    /* If blinding, compute post-image of plaintext by multiplying by
    ** blinding factor
    */
    if (nssRSAUseBlinding) {
	/* m = m'*g mod n */
	CHECK_MPI_OK( mp_mulmod(&m, &g, &n, &m) );
    }
    err = mp_to_fixlen_octets(&m, output, modLen);
    if (err >= 0) err = MP_OKAY;
cleanup:
    mp_clear(&n);
    mp_clear(&c);
    mp_clear(&m);
    mp_clear(&f);
    mp_clear(&g);
    if (err) {
	MP_TO_SEC_ERROR(err);
	rv = SECFailure;
    }
    return rv;
}