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gecko/security/nss/lib/freebl/rsa.c
Kai Engert a37ca8f2ef Bug 669061, Upgrade to NSS 3.13, starting with NSS_3_13_BETA1, r=wtc 
--HG--
rename : security/nss/cmd/lib/SSLerrs.h => security/nss/lib/ssl/SSLerrs.h
rename : security/nss/cmd/lib/SECerrs.h => security/nss/lib/util/SECerrs.h
2011-08-19 17:27:10 +02:00

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/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1994-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* RSA key generation, public key op, private key op.
*
* $Id: rsa.c,v 1.42 2011/03/30 01:20:12 rrelyea%redhat.com Exp $
*/
#ifdef FREEBL_NO_DEPEND
#include "stubs.h"
#endif
#include "secerr.h"
#include "prclist.h"
#include "nssilock.h"
#include "prinit.h"
#include "blapi.h"
#include "mpi.h"
#include "mpprime.h"
#include "mplogic.h"
#include "secmpi.h"
#include "secitem.h"
#include "blapii.h"
/*
** Number of times to attempt to generate a prime (p or q) from a random
** seed (the seed changes for each iteration).
*/
#define MAX_PRIME_GEN_ATTEMPTS 10
/*
** Number of times to attempt to generate a key. The primes p and q change
** for each attempt.
*/
#define MAX_KEY_GEN_ATTEMPTS 10
/* Blinding Parameters max cache size */
#define RSA_BLINDING_PARAMS_MAX_CACHE_SIZE 20
/* exponent should not be greater than modulus */
#define BAD_RSA_KEY_SIZE(modLen, expLen) \
((expLen) > (modLen) || (modLen) > RSA_MAX_MODULUS_BITS/8 || \
(expLen) > RSA_MAX_EXPONENT_BITS/8)
struct blindingParamsStr;
typedef struct blindingParamsStr blindingParams;
struct blindingParamsStr {
blindingParams *next;
mp_int f, g; /* blinding parameter */
int counter; /* number of remaining uses of (f, g) */
};
/*
** RSABlindingParamsStr
**
** For discussion of Paul Kocher's timing attack against an RSA private key
** operation, see http://www.cryptography.com/timingattack/paper.html. The
** countermeasure to this attack, known as blinding, is also discussed in
** the Handbook of Applied Cryptography, 11.118-11.119.
*/
struct RSABlindingParamsStr
{
/* Blinding-specific parameters */
PRCList link; /* link to list of structs */
SECItem modulus; /* list element "key" */
blindingParams *free, *bp; /* Blinding parameters queue */
blindingParams array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE];
};
typedef struct RSABlindingParamsStr RSABlindingParams;
/*
** RSABlindingParamsListStr
**
** List of key-specific blinding params. The arena holds the volatile pool
** of memory for each entry and the list itself. The lock is for list
** operations, in this case insertions and iterations, as well as control
** of the counter for each set of blinding parameters.
*/
struct RSABlindingParamsListStr
{
PZLock *lock; /* Lock for the list */
PRCondVar *cVar; /* Condidtion Variable */
int waitCount; /* Number of threads waiting on cVar */
PRCList head; /* Pointer to the list */
};
/*
** The master blinding params list.
*/
static struct RSABlindingParamsListStr blindingParamsList = { 0 };
/* Number of times to reuse (f, g). Suggested by Paul Kocher */
#define RSA_BLINDING_PARAMS_MAX_REUSE 50
/* Global, allows optional use of blinding. On by default. */
/* Cannot be changed at the moment, due to thread-safety issues. */
static PRBool nssRSAUseBlinding = PR_TRUE;
static SECStatus
rsa_build_from_primes(mp_int *p, mp_int *q,
mp_int *e, PRBool needPublicExponent,
mp_int *d, PRBool needPrivateExponent,
RSAPrivateKey *key, unsigned int keySizeInBits)
{
mp_int n, phi;
mp_int psub1, qsub1, tmp;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&n) = 0;
MP_DIGITS(&phi) = 0;
MP_DIGITS(&psub1) = 0;
MP_DIGITS(&qsub1) = 0;
MP_DIGITS(&tmp) = 0;
CHECK_MPI_OK( mp_init(&n) );
CHECK_MPI_OK( mp_init(&phi) );
CHECK_MPI_OK( mp_init(&psub1) );
CHECK_MPI_OK( mp_init(&qsub1) );
CHECK_MPI_OK( mp_init(&tmp) );
/* 1. Compute n = p*q */
CHECK_MPI_OK( mp_mul(p, q, &n) );
/* verify that the modulus has the desired number of bits */
if ((unsigned)mpl_significant_bits(&n) != keySizeInBits) {
PORT_SetError(SEC_ERROR_NEED_RANDOM);
rv = SECFailure;
goto cleanup;
}
/* at least one exponent must be given */
PORT_Assert(!(needPublicExponent && needPrivateExponent));
/* 2. Compute phi = (p-1)*(q-1) */
CHECK_MPI_OK( mp_sub_d(p, 1, &psub1) );
CHECK_MPI_OK( mp_sub_d(q, 1, &qsub1) );
if (needPublicExponent || needPrivateExponent) {
CHECK_MPI_OK( mp_mul(&psub1, &qsub1, &phi) );
/* 3. Compute d = e**-1 mod(phi) */
/* or e = d**-1 mod(phi) as necessary */
if (needPublicExponent) {
err = mp_invmod(d, &phi, e);
} else {
err = mp_invmod(e, &phi, d);
}
} else {
err = MP_OKAY;
}
/* Verify that phi(n) and e have no common divisors */
if (err != MP_OKAY) {
if (err == MP_UNDEF) {
PORT_SetError(SEC_ERROR_NEED_RANDOM);
err = MP_OKAY; /* to keep PORT_SetError from being called again */
rv = SECFailure;
}
goto cleanup;
}
/* 4. Compute exponent1 = d mod (p-1) */
CHECK_MPI_OK( mp_mod(d, &psub1, &tmp) );
MPINT_TO_SECITEM(&tmp, &key->exponent1, key->arena);
/* 5. Compute exponent2 = d mod (q-1) */
CHECK_MPI_OK( mp_mod(d, &qsub1, &tmp) );
MPINT_TO_SECITEM(&tmp, &key->exponent2, key->arena);
/* 6. Compute coefficient = q**-1 mod p */
CHECK_MPI_OK( mp_invmod(q, p, &tmp) );
MPINT_TO_SECITEM(&tmp, &key->coefficient, key->arena);
/* copy our calculated results, overwrite what is there */
key->modulus.data = NULL;
MPINT_TO_SECITEM(&n, &key->modulus, key->arena);
key->privateExponent.data = NULL;
MPINT_TO_SECITEM(d, &key->privateExponent, key->arena);
key->publicExponent.data = NULL;
MPINT_TO_SECITEM(e, &key->publicExponent, key->arena);
key->prime1.data = NULL;
MPINT_TO_SECITEM(p, &key->prime1, key->arena);
key->prime2.data = NULL;
MPINT_TO_SECITEM(q, &key->prime2, key->arena);
cleanup:
mp_clear(&n);
mp_clear(&phi);
mp_clear(&psub1);
mp_clear(&qsub1);
mp_clear(&tmp);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
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 and return a new RSA public and private key.
** Both keys are encoded in a single RSAPrivateKey structure.
** "cx" is the random number generator context
** "keySizeInBits" is the size of the key to be generated, in bits.
** 512, 1024, etc.
** "publicExponent" when not NULL is a pointer to some data that
** represents the public exponent to use. The data is a byte
** encoded integer, in "big endian" order.
*/
RSAPrivateKey *
RSA_NewKey(int keySizeInBits, SECItem *publicExponent)
{
unsigned int primeLen;
mp_int p, q, e, d;
int kiter;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
int prerr = 0;
RSAPrivateKey *key = NULL;
PRArenaPool *arena = NULL;
/* Require key size to be a multiple of 16 bits. */
if (!publicExponent || keySizeInBits % 16 != 0 ||
BAD_RSA_KEY_SIZE(keySizeInBits/8, publicExponent->len)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return NULL;
}
/* 1. Allocate arena & key */
arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
if (!arena) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return NULL;
}
key = PORT_ArenaZNew(arena, RSAPrivateKey);
if (!key) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
PORT_FreeArena(arena, PR_TRUE);
return NULL;
}
key->arena = arena;
/* length of primes p and q (in bytes) */
primeLen = keySizeInBits / (2 * BITS_PER_BYTE);
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&d) = 0;
CHECK_MPI_OK( mp_init(&p) );
CHECK_MPI_OK( mp_init(&q) );
CHECK_MPI_OK( mp_init(&e) );
CHECK_MPI_OK( mp_init(&d) );
/* 2. Set the version number (PKCS1 v1.5 says it should be zero) */
SECITEM_AllocItem(arena, &key->version, 1);
key->version.data[0] = 0;
/* 3. Set the public exponent */
SECITEM_TO_MPINT(*publicExponent, &e);
kiter = 0;
do {
prerr = 0;
PORT_SetError(0);
CHECK_SEC_OK( generate_prime(&p, primeLen) );
CHECK_SEC_OK( generate_prime(&q, primeLen) );
/* Assure q < p */
if (mp_cmp(&p, &q) < 0)
mp_exch(&p, &q);
/* Attempt to use these primes to generate a key */
rv = rsa_build_from_primes(&p, &q,
&e, PR_FALSE, /* needPublicExponent=false */
&d, PR_TRUE, /* needPrivateExponent=true */
key, keySizeInBits);
if (rv == SECSuccess)
break; /* generated two good primes */
prerr = PORT_GetError();
kiter++;
/* loop until have primes */
} while (prerr == SEC_ERROR_NEED_RANDOM && kiter < MAX_KEY_GEN_ATTEMPTS);
if (prerr)
goto cleanup;
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&e);
mp_clear(&d);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
if (rv && arena) {
PORT_FreeArena(arena, PR_TRUE);
key = NULL;
}
return key;
}
mp_err
rsa_is_prime(mp_int *p) {
int res;
/* run a Fermat test */
res = mpp_fermat(p, 2);
if (res != MP_OKAY) {
return res;
}
/* If that passed, run some Miller-Rabin tests */
res = mpp_pprime(p, 2);
return res;
}
/*
* Try to find the two primes based on 2 exponents plus either a prime
* or a modulus.
*
* In: e, d and either p or n (depending on the setting of hasModulus).
* Out: p,q.
*
* Step 1, Since d = e**-1 mod phi, we know that d*e == 1 mod phi, or
* d*e = 1+k*phi, or d*e-1 = k*phi. since d is less than phi and e is
* usually less than d, then k must be an integer between e-1 and 1
* (probably on the order of e).
* Step 1a, If we were passed just a prime, we can divide k*phi by that
* prime-1 and get k*(q-1). This will reduce the size of our division
* through the rest of the loop.
* Step 2, Loop through the values k=e-1 to 1 looking for k. k should be on
* the order or e, and e is typically small. This may take a while for
* a large random e. We are looking for a k that divides kphi
* evenly. Once we find a k that divides kphi evenly, we assume it
* is the true k. It's possible this k is not the 'true' k but has
* swapped factors of p-1 and/or q-1. Because of this, we
* tentatively continue Steps 3-6 inside this loop, and may return looking
* for another k on failure.
* Step 3, Calculate are tentative phi=kphi/k. Note: real phi is (p-1)*(q-1).
* Step 4a, if we have a prime, kphi is already k*(q-1), so phi is or tenative
* q-1. q = phi+1. If k is correct, q should be the right length and
* prime.
* Step 4b, It's possible q-1 and k could have swapped factors. We now have a
* possible solution that meets our criteria. It may not be the only
* solution, however, so we keep looking. If we find more than one,
* we will fail since we cannot determine which is the correct
* solution, and returning the wrong modulus will compromise both
* moduli. If no other solution is found, we return the unique solution.
* Step 5a, If we have the modulus (n=pq), then use the following formula to
* calculate s=(p+q): , phi = (p-1)(q-1) = pq -p-q +1 = n-s+1. so
* s=n-phi+1.
* Step 5b, Use n=pq and s=p+q to solve for p and q as follows:
* since q=s-p, then n=p*(s-p)= sp - p^2, rearranging p^2-s*p+n = 0.
* from the quadratic equation we have p=1/2*(s+sqrt(s*s-4*n)) and
* q=1/2*(s-sqrt(s*s-4*n)) if s*s-4*n is a perfect square, we are DONE.
* If it is not, continue in our look looking for another k. NOTE: the
* code actually distributes the 1/2 and results in the equations:
* sqrt = sqrt(s/2*s/2-n), p=s/2+sqrt, q=s/2-sqrt. The algebra saves us
* and extra divide by 2 and a multiply by 4.
*
* This will return p & q. q may be larger than p in the case that p was given
* and it was the smaller prime.
*/
static mp_err
rsa_get_primes_from_exponents(mp_int *e, mp_int *d, mp_int *p, mp_int *q,
mp_int *n, PRBool hasModulus,
unsigned int keySizeInBits)
{
mp_int kphi; /* k*phi */
mp_int k; /* current guess at 'k' */
mp_int phi; /* (p-1)(q-1) */
mp_int s; /* p+q/2 (s/2 in the algebra) */
mp_int r; /* remainder */
mp_int tmp; /* p-1 if p is given, n+1 is modulus is given */
mp_int sqrt; /* sqrt(s/2*s/2-n) */
mp_err err = MP_OKAY;
unsigned int order_k;
MP_DIGITS(&kphi) = 0;
MP_DIGITS(&phi) = 0;
MP_DIGITS(&s) = 0;
MP_DIGITS(&k) = 0;
MP_DIGITS(&r) = 0;
MP_DIGITS(&tmp) = 0;
MP_DIGITS(&sqrt) = 0;
CHECK_MPI_OK( mp_init(&kphi) );
CHECK_MPI_OK( mp_init(&phi) );
CHECK_MPI_OK( mp_init(&s) );
CHECK_MPI_OK( mp_init(&k) );
CHECK_MPI_OK( mp_init(&r) );
CHECK_MPI_OK( mp_init(&tmp) );
CHECK_MPI_OK( mp_init(&sqrt) );
/* our algorithm looks for a factor k whose maximum size is dependent
* on the size of our smallest exponent, which had better be the public
* exponent (if it's the private, the key is vulnerable to a brute force
* attack).
*
* since our factor search is linear, we need to limit the maximum
* size of the public key. this should not be a problem normally, since
* public keys are usually small.
*
* if we want to handle larger public key sizes, we should have
* a version which tries to 'completely' factor k*phi (where completely
* means 'factor into primes, or composites with which are products of
* large primes). Once we have all the factors, we can sort them out and
* try different combinations to form our phi. The risk is if (p-1)/2,
* (q-1)/2, and k are all large primes. In any case if the public key
* is small (order of 20 some bits), then a linear search for k is
* manageable.
*/
if (mpl_significant_bits(e) > 23) {
err=MP_RANGE;
goto cleanup;
}
/* calculate k*phi = e*d - 1 */
CHECK_MPI_OK( mp_mul(e, d, &kphi) );
CHECK_MPI_OK( mp_sub_d(&kphi, 1, &kphi) );
/* kphi is (e*d)-1, which is the same as k*(p-1)(q-1)
* d < (p-1)(q-1), therefor k must be less than e-1
* We can narrow down k even more, though. Since p and q are odd and both
* have their high bit set, then we know that phi must be on order of
* keySizeBits.
*/
order_k = (unsigned)mpl_significant_bits(&kphi) - keySizeInBits;
/* for (k=kinit; order(k) >= order_k; k--) { */
/* k=kinit: k can't be bigger than kphi/2^(keySizeInBits -1) */
CHECK_MPI_OK( mp_2expt(&k,keySizeInBits-1) );
CHECK_MPI_OK( mp_div(&kphi, &k, &k, NULL));
if (mp_cmp(&k,e) >= 0) {
/* also can't be bigger then e-1 */
CHECK_MPI_OK( mp_sub_d(e, 1, &k) );
}
/* calculate our temp value */
/* This saves recalculating this value when the k guess is wrong, which
* is reasonably frequent. */
/* for the modulus case, tmp = n+1 (used to calculate p+q = tmp - phi) */
/* for the prime case, tmp = p-1 (used to calculate q-1= phi/tmp) */
if (hasModulus) {
CHECK_MPI_OK( mp_add_d(n, 1, &tmp) );
} else {
CHECK_MPI_OK( mp_sub_d(p, 1, &tmp) );
CHECK_MPI_OK(mp_div(&kphi,&tmp,&kphi,&r));
if (mp_cmp_z(&r) != 0) {
/* p-1 doesn't divide kphi, some parameter wasn't correct */
err=MP_RANGE;
goto cleanup;
}
mp_zero(q);
/* kphi is now k*(q-1) */
}
/* rest of the for loop */
for (; (err == MP_OKAY) && (mpl_significant_bits(&k) >= order_k);
err = mp_sub_d(&k, 1, &k)) {
/* looking for k as a factor of kphi */
CHECK_MPI_OK(mp_div(&kphi,&k,&phi,&r));
if (mp_cmp_z(&r) != 0) {
/* not a factor, try the next one */
continue;
}
/* we have a possible phi, see if it works */
if (!hasModulus) {
if ((unsigned)mpl_significant_bits(&phi) != keySizeInBits/2) {
/* phi is not the right size */
continue;
}
/* phi should be divisible by 2, since
* q is odd and phi=(q-1). */
if (mpp_divis_d(&phi,2) == MP_NO) {
/* phi is not divisible by 4 */
continue;
}
/* we now have a candidate for the second prime */
CHECK_MPI_OK(mp_add_d(&phi, 1, &tmp));
/* check to make sure it is prime */
err = rsa_is_prime(&tmp);
if (err != MP_OKAY) {
if (err == MP_NO) {
/* No, then we still have the wrong phi */
err = MP_OKAY;
continue;
}
goto cleanup;
}
/*
* It is possible that we have the wrong phi if
* k_guess*(q_guess-1) = k*(q-1) (k and q-1 have swapped factors).
* since our q_quess is prime, however. We have found a valid
* rsa key because:
* q is the correct order of magnitude.
* phi = (p-1)(q-1) where p and q are both primes.
* e*d mod phi = 1.
* There is no way to know from the info given if this is the
* original key. We never want to return the wrong key because if
* two moduli with the same factor is known, then euclid's gcd
* algorithm can be used to find that factor. Even though the
* caller didn't pass the original modulus, it doesn't mean the
* modulus wasn't known or isn't available somewhere. So to be safe
* if we can't be sure we have the right q, we don't return any.
*
* So to make sure we continue looking for other valid q's. If none
* are found, then we can safely return this one, otherwise we just
* fail */
if (mp_cmp_z(q) != 0) {
/* this is the second valid q, don't return either,
* just fail */
err = MP_RANGE;
break;
}
/* we only have one q so far, save it and if no others are found,
* it's safe to return it */
CHECK_MPI_OK(mp_copy(&tmp, q));
continue;
}
/* test our tentative phi */
/* phi should be the correct order */
if ((unsigned)mpl_significant_bits(&phi) != keySizeInBits) {
/* phi is not the right size */
continue;
}
/* phi should be divisible by 4, since
* p and q are odd and phi=(p-1)(q-1). */
if (mpp_divis_d(&phi,4) == MP_NO) {
/* phi is not divisible by 4 */
continue;
}
/* n was given, calculate s/2=(p+q)/2 */
CHECK_MPI_OK( mp_sub(&tmp, &phi, &s) );
CHECK_MPI_OK( mp_div_2(&s, &s) );
/* calculate sqrt(s/2*s/2-n) */
CHECK_MPI_OK(mp_sqr(&s,&sqrt));
CHECK_MPI_OK(mp_sub(&sqrt,n,&r)); /* r as a tmp */
CHECK_MPI_OK(mp_sqrt(&r,&sqrt));
/* make sure it's a perfect square */
/* r is our original value we took the square root of */
/* q is the square of our tentative square root. They should be equal*/
CHECK_MPI_OK(mp_sqr(&sqrt,q)); /* q as a tmp */
if (mp_cmp(&r,q) != 0) {
/* sigh according to the doc, mp_sqrt could return sqrt-1 */
CHECK_MPI_OK(mp_add_d(&sqrt,1,&sqrt));
CHECK_MPI_OK(mp_sqr(&sqrt,q));
if (mp_cmp(&r,q) != 0) {
/* s*s-n not a perfect square, this phi isn't valid, find * another.*/
continue;
}
}
/* NOTE: In this case we know we have the one and only answer.
* "Why?", you ask. Because:
* 1) n is a composite of two large primes (or it wasn't a
* valid RSA modulus).
* 2) If we know any number such that x^2-n is a perfect square
* and x is not (n+1)/2, then we can calculate 2 non-trivial
* factors of n.
* 3) Since we know that n has only 2 non-trivial prime factors,
* we know the two factors we have are the only possible factors.
*/
/* Now we are home free to calculate p and q */
/* p = s/2 + sqrt, q= s/2 - sqrt */
CHECK_MPI_OK(mp_add(&s,&sqrt,p));
CHECK_MPI_OK(mp_sub(&s,&sqrt,q));
break;
}
if ((unsigned)mpl_significant_bits(&k) < order_k) {
if (hasModulus || (mp_cmp_z(q) == 0)) {
/* If we get here, something was wrong with the parameters we
* were given */
err = MP_RANGE;
}
}
cleanup:
mp_clear(&kphi);
mp_clear(&phi);
mp_clear(&s);
mp_clear(&k);
mp_clear(&r);
mp_clear(&tmp);
mp_clear(&sqrt);
return err;
}
/*
* take a private key with only a few elements and fill out the missing pieces.
*
* All the entries will be overwritten with data allocated out of the arena
* If no arena is supplied, one will be created.
*
* The following fields must be supplied in order for this function
* to succeed:
* one of either publicExponent or privateExponent
* two more of the following 5 parameters.
* modulus (n)
* prime1 (p)
* prime2 (q)
* publicExponent (e)
* privateExponent (d)
*
* NOTE: if only the publicExponent, privateExponent, and one prime is given,
* then there may be more than one RSA key that matches that combination.
*
* All parameters will be replaced in the key structure with new parameters
* Allocated out of the arena. There is no attempt to free the old structures.
* Prime1 will always be greater than prime2 (even if the caller supplies the
* smaller prime as prime1 or the larger prime as prime2). The parameters are
* not overwritten on failure.
*
* How it works:
* We can generate all the parameters from:
* one of the exponents, plus the two primes. (rsa_build_key_from_primes) *
* If we are given one of the exponents and both primes, we are done.
* If we are given one of the exponents, the modulus and one prime, we
* caclulate the second prime by dividing the modulus by the given
* prime, giving us and exponent and 2 primes.
* If we are given 2 exponents and either the modulus or one of the primes
* we calculate k*phi = d*e-1, where k is an integer less than d which
* divides d*e-1. We find factor k so we can isolate phi.
* phi = (p-1)(q-1)
* If one of the primes are given, we can use phi to find the other prime
* as follows: q = (phi/(p-1)) + 1. We now have 2 primes and an
* exponent. (NOTE: if more then one prime meets this condition, the
* operation will fail. See comments elsewhere in this file about this).
* If the modulus is given, then we can calculate the sum of the primes
* as follows: s := (p+q), phi = (p-1)(q-1) = pq -p - q +1, pq = n ->
* phi = n - s + 1, s = n - phi +1. Now that we have s = p+q and n=pq,
* we can solve our 2 equations and 2 unknowns as follows: q=s-p ->
* n=p*(s-p)= sp -p^2 -> p^2-sp+n = 0. Using the quadratic to solve for
* p, p=1/2*(s+ sqrt(s*s-4*n)) [q=1/2*(s-sqrt(s*s-4*n)]. We again have
* 2 primes and an exponent.
*
*/
SECStatus
RSA_PopulatePrivateKey(RSAPrivateKey *key)
{
PRArenaPool *arena = NULL;
PRBool needPublicExponent = PR_TRUE;
PRBool needPrivateExponent = PR_TRUE;
PRBool hasModulus = PR_FALSE;
unsigned int keySizeInBits = 0;
int prime_count = 0;
/* standard RSA nominclature */
mp_int p, q, e, d, n;
/* remainder */
mp_int r;
mp_err err = 0;
SECStatus rv = SECFailure;
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&d) = 0;
MP_DIGITS(&n) = 0;
MP_DIGITS(&r) = 0;
CHECK_MPI_OK( mp_init(&p) );
CHECK_MPI_OK( mp_init(&q) );
CHECK_MPI_OK( mp_init(&e) );
CHECK_MPI_OK( mp_init(&d) );
CHECK_MPI_OK( mp_init(&n) );
CHECK_MPI_OK( mp_init(&r) );
/* if the key didn't already have an arena, create one. */
if (key->arena == NULL) {
arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
if (!arena) {
goto cleanup;
}
key->arena = arena;
}
/* load up the known exponents */
if (key->publicExponent.data) {
SECITEM_TO_MPINT(key->publicExponent, &e);
needPublicExponent = PR_FALSE;
}
if (key->privateExponent.data) {
SECITEM_TO_MPINT(key->privateExponent, &d);
needPrivateExponent = PR_FALSE;
}
if (needPrivateExponent && needPublicExponent) {
/* Not enough information, we need at least one exponent */
err = MP_BADARG;
goto cleanup;
}
/* load up the known primes. If only one prime is given, it will be
* assigned 'p'. Once we have both primes, well make sure p is the larger.
* The value prime_count tells us howe many we have acquired.
*/
if (key->prime1.data) {
int primeLen = key->prime1.len;
if (key->prime1.data[0] == 0) {
primeLen--;
}
keySizeInBits = primeLen * 2 * BITS_PER_BYTE;
SECITEM_TO_MPINT(key->prime1, &p);
prime_count++;
}
if (key->prime2.data) {
int primeLen = key->prime2.len;
if (key->prime2.data[0] == 0) {
primeLen--;
}
keySizeInBits = primeLen * 2 * BITS_PER_BYTE;
SECITEM_TO_MPINT(key->prime2, prime_count ? &q : &p);
prime_count++;
}
/* load up the modulus */
if (key->modulus.data) {
int modLen = key->modulus.len;
if (key->modulus.data[0] == 0) {
modLen--;
}
keySizeInBits = modLen * BITS_PER_BYTE;
SECITEM_TO_MPINT(key->modulus, &n);
hasModulus = PR_TRUE;
}
/* if we have the modulus and one prime, calculate the second. */
if ((prime_count == 1) && (hasModulus)) {
mp_div(&n,&p,&q,&r);
if (mp_cmp_z(&r) != 0) {
/* p is not a factor or n, fail */
err = MP_BADARG;
goto cleanup;
}
prime_count++;
}
/* If we didn't have enough primes try to calculate the primes from
* the exponents */
if (prime_count < 2) {
/* if we don't have at least 2 primes at this point, then we need both
* exponents and one prime or a modulus*/
if (!needPublicExponent && !needPrivateExponent &&
((prime_count > 0) || hasModulus)) {
CHECK_MPI_OK(rsa_get_primes_from_exponents(&e,&d,&p,&q,
&n,hasModulus,keySizeInBits));
} else {
/* not enough given parameters to get both primes */
err = MP_BADARG;
goto cleanup;
}
}
/* force p to the the larger prime */
if (mp_cmp(&p, &q) < 0)
mp_exch(&p, &q);
/* we now have our 2 primes and at least one exponent, we can fill
* in the key */
rv = rsa_build_from_primes(&p, &q,
&e, needPublicExponent,
&d, needPrivateExponent,
key, keySizeInBits);
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&e);
mp_clear(&d);
mp_clear(&n);
mp_clear(&r);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
if (rv && arena) {
PORT_FreeArena(arena, PR_TRUE);
key->arena = NULL;
}
return rv;
}
static unsigned int
rsa_modulusLen(SECItem *modulus)
{
unsigned char byteZero = modulus->data[0];
unsigned int modLen = modulus->len - !byteZero;
return modLen;
}
/*
** Perform a raw public-key operation
** Length of input and output buffers are equal to key's modulus len.
*/
SECStatus
RSA_PublicKeyOp(RSAPublicKey *key,
unsigned char *output,
const unsigned char *input)
{
unsigned int modLen, expLen, offset;
mp_int n, e, m, c;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
if (!key || !output || !input) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
MP_DIGITS(&n) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&m) = 0;
MP_DIGITS(&c) = 0;
CHECK_MPI_OK( mp_init(&n) );
CHECK_MPI_OK( mp_init(&e) );
CHECK_MPI_OK( mp_init(&m) );
CHECK_MPI_OK( mp_init(&c) );
modLen = rsa_modulusLen(&key->modulus);
expLen = rsa_modulusLen(&key->publicExponent);
/* 1. Obtain public key (n, e) */
if (BAD_RSA_KEY_SIZE(modLen, expLen)) {
PORT_SetError(SEC_ERROR_INVALID_KEY);
rv = SECFailure;
goto cleanup;
}
SECITEM_TO_MPINT(key->modulus, &n);
SECITEM_TO_MPINT(key->publicExponent, &e);
if (e.used > n.used) {
/* exponent should not be greater than modulus */
PORT_SetError(SEC_ERROR_INVALID_KEY);
rv = SECFailure;
goto cleanup;
}
/* 2. check input out of range (needs to be in range [0..n-1]) */
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_INPUT_LEN);
rv = SECFailure;
goto cleanup;
}
/* 2 bis. Represent message as integer in range [0..n-1] */
CHECK_MPI_OK( mp_read_unsigned_octets(&m, input, modLen) );
/* 3. Compute c = m**e mod n */
#ifdef USE_MPI_EXPT_D
/* XXX see which is faster */
if (MP_USED(&e) == 1) {
CHECK_MPI_OK( mp_exptmod_d(&m, MP_DIGIT(&e, 0), &n, &c) );
} else
#endif
CHECK_MPI_OK( mp_exptmod(&m, &e, &n, &c) );
/* 4. result c is ciphertext */
err = mp_to_fixlen_octets(&c, output, modLen);
if (err >= 0) err = MP_OKAY;
cleanup:
mp_clear(&n);
mp_clear(&e);
mp_clear(&m);
mp_clear(&c);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/*
** 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;
}
/*
** RSA Private key operation using CRT.
*/
static SECStatus
rsa_PrivateKeyOpCRTNoCheck(RSAPrivateKey *key, mp_int *m, mp_int *c)
{
mp_int p, q, d_p, d_q, qInv;
mp_int m1, m2, h, ctmp;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&d_p) = 0;
MP_DIGITS(&d_q) = 0;
MP_DIGITS(&qInv) = 0;
MP_DIGITS(&m1) = 0;
MP_DIGITS(&m2) = 0;
MP_DIGITS(&h) = 0;
MP_DIGITS(&ctmp) = 0;
CHECK_MPI_OK( mp_init(&p) );
CHECK_MPI_OK( mp_init(&q) );
CHECK_MPI_OK( mp_init(&d_p) );
CHECK_MPI_OK( mp_init(&d_q) );
CHECK_MPI_OK( mp_init(&qInv) );
CHECK_MPI_OK( mp_init(&m1) );
CHECK_MPI_OK( mp_init(&m2) );
CHECK_MPI_OK( mp_init(&h) );
CHECK_MPI_OK( mp_init(&ctmp) );
/* copy private key parameters into mp integers */
SECITEM_TO_MPINT(key->prime1, &p); /* p */
SECITEM_TO_MPINT(key->prime2, &q); /* q */
SECITEM_TO_MPINT(key->exponent1, &d_p); /* d_p = d mod (p-1) */
SECITEM_TO_MPINT(key->exponent2, &d_q); /* d_q = d mod (q-1) */
SECITEM_TO_MPINT(key->coefficient, &qInv); /* qInv = q**-1 mod p */
/* 1. m1 = c**d_p mod p */
CHECK_MPI_OK( mp_mod(c, &p, &ctmp) );
CHECK_MPI_OK( mp_exptmod(&ctmp, &d_p, &p, &m1) );
/* 2. m2 = c**d_q mod q */
CHECK_MPI_OK( mp_mod(c, &q, &ctmp) );
CHECK_MPI_OK( mp_exptmod(&ctmp, &d_q, &q, &m2) );
/* 3. h = (m1 - m2) * qInv mod p */
CHECK_MPI_OK( mp_submod(&m1, &m2, &p, &h) );
CHECK_MPI_OK( mp_mulmod(&h, &qInv, &p, &h) );
/* 4. m = m2 + h * q */
CHECK_MPI_OK( mp_mul(&h, &q, m) );
CHECK_MPI_OK( mp_add(m, &m2, m) );
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&d_p);
mp_clear(&d_q);
mp_clear(&qInv);
mp_clear(&m1);
mp_clear(&m2);
mp_clear(&h);
mp_clear(&ctmp);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/*
** 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;
}
static PRCallOnceType coBPInit = { 0, 0, 0 };
static PRStatus
init_blinding_params_list(void)
{
blindingParamsList.lock = PZ_NewLock(nssILockOther);
if (!blindingParamsList.lock) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return PR_FAILURE;
}
blindingParamsList.cVar = PR_NewCondVar( blindingParamsList.lock );
if (!blindingParamsList.cVar) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return PR_FAILURE;
}
blindingParamsList.waitCount = 0;
PR_INIT_CLIST(&blindingParamsList.head);
return PR_SUCCESS;
}
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;
}
static SECStatus
init_blinding_params(RSABlindingParams *rsabp, RSAPrivateKey *key,
mp_int *n, unsigned int modLen)
{
blindingParams * bp = rsabp->array;
SECStatus rv = SECSuccess;
mp_err err = MP_OKAY;
int i = 0;
/* Initialize the list pointer for the element */
PR_INIT_CLIST(&rsabp->link);
for (i = 0; i < RSA_BLINDING_PARAMS_MAX_CACHE_SIZE; ++i, ++bp) {
bp->next = bp + 1;
MP_DIGITS(&bp->f) = 0;
MP_DIGITS(&bp->g) = 0;
bp->counter = 0;
}
/* The last bp->next value was initialized with out
* of rsabp->array pointer and must be set to NULL
*/
rsabp->array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE - 1].next = NULL;
bp = rsabp->array;
rsabp->bp = NULL;
rsabp->free = bp;
/* List elements are keyed using the modulus */
SECITEM_CopyItem(NULL, &rsabp->modulus, &key->modulus);
return SECSuccess;
}
static SECStatus
get_blinding_params(RSAPrivateKey *key, mp_int *n, unsigned int modLen,
mp_int *f, mp_int *g)
{
RSABlindingParams *rsabp = NULL;
blindingParams *bpUnlinked = NULL;
blindingParams *bp, *prevbp = NULL;
PRCList *el;
SECStatus rv = SECSuccess;
mp_err err = MP_OKAY;
int cmp = -1;
PRBool holdingLock = PR_FALSE;
do {
if (blindingParamsList.lock == NULL) {
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
return SECFailure;
}
/* Acquire the list lock */
PZ_Lock(blindingParamsList.lock);
holdingLock = PR_TRUE;
/* Walk the list looking for the private key */
for (el = PR_NEXT_LINK(&blindingParamsList.head);
el != &blindingParamsList.head;
el = PR_NEXT_LINK(el)) {
rsabp = (RSABlindingParams *)el;
cmp = SECITEM_CompareItem(&rsabp->modulus, &key->modulus);
if (cmp >= 0) {
/* The key is found or not in the list. */
break;
}
}
if (cmp) {
/* At this point, the key is not in the list. el should point to
** the list element before which this key should be inserted.
*/
rsabp = PORT_ZNew(RSABlindingParams);
if (!rsabp) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
rv = init_blinding_params(rsabp, key, n, modLen);
if (rv != SECSuccess) {
PORT_ZFree(rsabp, sizeof(RSABlindingParams));
goto cleanup;
}
/* Insert the new element into the list
** If inserting in the middle of the list, el points to the link
** to insert before. Otherwise, the link needs to be appended to
** the end of the list, which is the same as inserting before the
** head (since el would have looped back to the head).
*/
PR_INSERT_BEFORE(&rsabp->link, el);
}
/* We've found (or created) the RSAblindingParams struct for this key.
* Now, search its list of ready blinding params for a usable one.
*/
while (0 != (bp = rsabp->bp)) {
if (--(bp->counter) > 0) {
/* Found a match and there are still remaining uses left */
/* Return the parameters */
CHECK_MPI_OK( mp_copy(&bp->f, f) );
CHECK_MPI_OK( mp_copy(&bp->g, g) );
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
}
/* exhausted this one, give its values to caller, and
* then retire it.
*/
mp_exch(&bp->f, f);
mp_exch(&bp->g, g);
mp_clear( &bp->f );
mp_clear( &bp->g );
bp->counter = 0;
/* Move to free list */
rsabp->bp = bp->next;
bp->next = rsabp->free;
rsabp->free = bp;
/* In case there're threads waiting for new blinding
* value - notify 1 thread the value is ready
*/
if (blindingParamsList.waitCount > 0) {
PR_NotifyCondVar( blindingParamsList.cVar );
blindingParamsList.waitCount--;
}
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
}
/* We did not find a usable set of blinding params. Can we make one?
/* Find a free bp struct. */
prevbp = NULL;
if ((bp = rsabp->free) != NULL) {
/* unlink this bp */
rsabp->free = bp->next;
bp->next = NULL;
bpUnlinked = bp; /* In case we fail */
PZ_Unlock(blindingParamsList.lock);
holdingLock = PR_FALSE;
/* generate blinding parameter values for the current thread */
CHECK_SEC_OK( generate_blinding_params(key, f, g, n, modLen ) );
/* put the blinding parameter values into cache */
CHECK_MPI_OK( mp_init( &bp->f) );
CHECK_MPI_OK( mp_init( &bp->g) );
CHECK_MPI_OK( mp_copy( f, &bp->f) );
CHECK_MPI_OK( mp_copy( g, &bp->g) );
/* Put this at head of queue of usable params. */
PZ_Lock(blindingParamsList.lock);
holdingLock = PR_TRUE;
/* initialize RSABlindingParamsStr */
bp->counter = RSA_BLINDING_PARAMS_MAX_REUSE;
bp->next = rsabp->bp;
rsabp->bp = bp;
bpUnlinked = NULL;
/* In case there're threads waiting for new blinding value
* just notify them the value is ready
*/
if (blindingParamsList.waitCount > 0) {
PR_NotifyAllCondVar( blindingParamsList.cVar );
blindingParamsList.waitCount = 0;
}
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
}
/* Here, there are no usable blinding parameters available,
* and no free bp blocks, presumably because they're all
* actively having parameters generated for them.
* So, we need to wait here and not eat up CPU until some
* change happens.
*/
blindingParamsList.waitCount++;
PR_WaitCondVar( blindingParamsList.cVar, PR_INTERVAL_NO_TIMEOUT );
PZ_Unlock(blindingParamsList.lock);
holdingLock = PR_FALSE;
} while (1);
cleanup:
/* It is possible to reach this after the lock is already released. */
if (bpUnlinked) {
if (!holdingLock) {
PZ_Lock(blindingParamsList.lock);
holdingLock = PR_TRUE;
}
bp = bpUnlinked;
mp_clear( &bp->f );
mp_clear( &bp->g );
bp->counter = 0;
/* Must put the unlinked bp back on the free list */
bp->next = rsabp->free;
rsabp->free = bp;
}
if (holdingLock) {
PZ_Unlock(blindingParamsList.lock);
holdingLock = PR_FALSE;
}
if (err) {
MP_TO_SEC_ERROR(err);
}
return SECFailure;
}
/*
** 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;
}
SECStatus
RSA_PrivateKeyOp(RSAPrivateKey *key,
unsigned char *output,
const unsigned char *input)
{
return rsa_PrivateKeyOp(key, output, input, PR_FALSE);
}
SECStatus
RSA_PrivateKeyOpDoubleChecked(RSAPrivateKey *key,
unsigned char *output,
const unsigned char *input)
{
return rsa_PrivateKeyOp(key, output, input, PR_TRUE);
}
static SECStatus
swap_in_key_value(PRArenaPool *arena, mp_int *mpval, SECItem *buffer)
{
int len;
mp_err err = MP_OKAY;
memset(buffer->data, 0, buffer->len);
len = mp_unsigned_octet_size(mpval);
if (len <= 0) return SECFailure;
if ((unsigned int)len <= buffer->len) {
/* The new value is no longer than the old buffer, so use it */
err = mp_to_unsigned_octets(mpval, buffer->data, len);
if (err >= 0) err = MP_OKAY;
buffer->len = len;
} else if (arena) {
/* The new value is longer, but working within an arena */
(void)SECITEM_AllocItem(arena, buffer, len);
err = mp_to_unsigned_octets(mpval, buffer->data, len);
if (err >= 0) err = MP_OKAY;
} else {
/* The new value is longer, no arena, can't handle this key */
return SECFailure;
}
return (err == MP_OKAY) ? SECSuccess : SECFailure;
}
SECStatus
RSA_PrivateKeyCheck(RSAPrivateKey *key)
{
mp_int p, q, n, psub1, qsub1, e, d, d_p, d_q, qInv, res;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&n) = 0;
MP_DIGITS(&psub1)= 0;
MP_DIGITS(&qsub1)= 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&d) = 0;
MP_DIGITS(&d_p) = 0;
MP_DIGITS(&d_q) = 0;
MP_DIGITS(&qInv) = 0;
MP_DIGITS(&res) = 0;
CHECK_MPI_OK( mp_init(&p) );
CHECK_MPI_OK( mp_init(&q) );
CHECK_MPI_OK( mp_init(&n) );
CHECK_MPI_OK( mp_init(&psub1));
CHECK_MPI_OK( mp_init(&qsub1));
CHECK_MPI_OK( mp_init(&e) );
CHECK_MPI_OK( mp_init(&d) );
CHECK_MPI_OK( mp_init(&d_p) );
CHECK_MPI_OK( mp_init(&d_q) );
CHECK_MPI_OK( mp_init(&qInv) );
CHECK_MPI_OK( mp_init(&res) );
SECITEM_TO_MPINT(key->modulus, &n);
SECITEM_TO_MPINT(key->prime1, &p);
SECITEM_TO_MPINT(key->prime2, &q);
SECITEM_TO_MPINT(key->publicExponent, &e);
SECITEM_TO_MPINT(key->privateExponent, &d);
SECITEM_TO_MPINT(key->exponent1, &d_p);
SECITEM_TO_MPINT(key->exponent2, &d_q);
SECITEM_TO_MPINT(key->coefficient, &qInv);
/* p > q */
if (mp_cmp(&p, &q) <= 0) {
/* mind the p's and q's (and d_p's and d_q's) */
SECItem tmp;
mp_exch(&p, &q);
mp_exch(&d_p,&d_q);
tmp = key->prime1;
key->prime1 = key->prime2;
key->prime2 = tmp;
tmp = key->exponent1;
key->exponent1 = key->exponent2;
key->exponent2 = tmp;
}
#define VERIFY_MPI_EQUAL(m1, m2) \
if (mp_cmp(m1, m2) != 0) { \
rv = SECFailure; \
goto cleanup; \
}
#define VERIFY_MPI_EQUAL_1(m) \
if (mp_cmp_d(m, 1) != 0) { \
rv = SECFailure; \
goto cleanup; \
}
/*
* The following errors cannot be recovered from.
*/
/* n == p * q */
CHECK_MPI_OK( mp_mul(&p, &q, &res) );
VERIFY_MPI_EQUAL(&res, &n);
/* gcd(e, p-1) == 1 */
CHECK_MPI_OK( mp_sub_d(&p, 1, &psub1) );
CHECK_MPI_OK( mp_gcd(&e, &psub1, &res) );
VERIFY_MPI_EQUAL_1(&res);
/* gcd(e, q-1) == 1 */
CHECK_MPI_OK( mp_sub_d(&q, 1, &qsub1) );
CHECK_MPI_OK( mp_gcd(&e, &qsub1, &res) );
VERIFY_MPI_EQUAL_1(&res);
/* d*e == 1 mod p-1 */
CHECK_MPI_OK( mp_mulmod(&d, &e, &psub1, &res) );
VERIFY_MPI_EQUAL_1(&res);
/* d*e == 1 mod q-1 */
CHECK_MPI_OK( mp_mulmod(&d, &e, &qsub1, &res) );
VERIFY_MPI_EQUAL_1(&res);
/*
* The following errors can be recovered from.
*/
/* d_p == d mod p-1 */
CHECK_MPI_OK( mp_mod(&d, &psub1, &res) );
if (mp_cmp(&d_p, &res) != 0) {
/* swap in the correct value */
CHECK_SEC_OK( swap_in_key_value(key->arena, &res, &key->exponent1) );
}
/* d_q == d mod q-1 */
CHECK_MPI_OK( mp_mod(&d, &qsub1, &res) );
if (mp_cmp(&d_q, &res) != 0) {
/* swap in the correct value */
CHECK_SEC_OK( swap_in_key_value(key->arena, &res, &key->exponent2) );
}
/* q * q**-1 == 1 mod p */
CHECK_MPI_OK( mp_mulmod(&q, &qInv, &p, &res) );
if (mp_cmp_d(&res, 1) != 0) {
/* compute the correct value */
CHECK_MPI_OK( mp_invmod(&q, &p, &qInv) );
CHECK_SEC_OK( swap_in_key_value(key->arena, &qInv, &key->coefficient) );
}
cleanup:
mp_clear(&n);
mp_clear(&p);
mp_clear(&q);
mp_clear(&psub1);
mp_clear(&qsub1);
mp_clear(&e);
mp_clear(&d);
mp_clear(&d_p);
mp_clear(&d_q);
mp_clear(&qInv);
mp_clear(&res);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
static SECStatus RSA_Init(void)
{
if (PR_CallOnce(&coBPInit, init_blinding_params_list) != PR_SUCCESS) {
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
return SECFailure;
}
return SECSuccess;
}
SECStatus BL_Init(void)
{
return RSA_Init();
}
/* cleanup at shutdown */
void RSA_Cleanup(void)
{
blindingParams * bp = NULL;
if (!coBPInit.initialized)
return;
while (!PR_CLIST_IS_EMPTY(&blindingParamsList.head)) {
RSABlindingParams *rsabp =
(RSABlindingParams *)PR_LIST_HEAD(&blindingParamsList.head);
PR_REMOVE_LINK(&rsabp->link);
/* clear parameters cache */
while (rsabp->bp != NULL) {
bp = rsabp->bp;
rsabp->bp = rsabp->bp->next;
mp_clear( &bp->f );
mp_clear( &bp->g );
}
SECITEM_FreeItem(&rsabp->modulus,PR_FALSE);
PORT_Free(rsabp);
}
if (blindingParamsList.cVar) {
PR_DestroyCondVar(blindingParamsList.cVar);
blindingParamsList.cVar = NULL;
}
if (blindingParamsList.lock) {
SKIP_AFTER_FORK(PZ_DestroyLock(blindingParamsList.lock));
blindingParamsList.lock = NULL;
}
coBPInit.initialized = 0;
coBPInit.inProgress = 0;
coBPInit.status = 0;
}
/*
* need a central place for this function to free up all the memory that
* free_bl may have allocated along the way. Currently only RSA does this,
* so I've put it here for now.
*/
void BL_Cleanup(void)
{
RSA_Cleanup();
}
PRBool bl_parentForkedAfterC_Initialize;
/*
* Set fork flag so it can be tested in SKIP_AFTER_FORK on relevant platforms.
*/
void BL_SetForkState(PRBool forked)
{
bl_parentForkedAfterC_Initialize = forked;
}
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