RetroZilla/security/nss/lib/freebl/rsa.c

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2015-10-21 05:03:22 +02:00
/* ***** 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 1.39 2009/02/03 05:34:41 julien.pierre.boogz%sun.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
/* 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)
/*
** 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" */
mp_int f, g; /* Blinding parameters */
int counter; /* number of remaining uses of (f, g) */
};
/*
** 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 */
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_keygen_from_primes(mp_int *p, mp_int *q, mp_int *e, RSAPrivateKey *key,
unsigned int keySizeInBits)
{
mp_int n, d, phi;
mp_int psub1, qsub1, tmp;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&n) = 0;
MP_DIGITS(&d) = 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(&d) );
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;
}
/* 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) );
CHECK_MPI_OK( mp_mul(&psub1, &qsub1, &phi) );
/* 3. Compute d = e**-1 mod(phi) */
err = mp_invmod(e, &phi, &d);
/* 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;
}
MPINT_TO_SECITEM(&n, &key->modulus, key->arena);
MPINT_TO_SECITEM(&d, &key->privateExponent, key->arena);
/* 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);
cleanup:
mp_clear(&n);
mp_clear(&d);
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;
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 = (RSAPrivateKey *)PORT_ArenaZAlloc(arena, sizeof(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;
CHECK_MPI_OK( mp_init(&p) );
CHECK_MPI_OK( mp_init(&q) );
CHECK_MPI_OK( mp_init(&e) );
/* 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_CopyItem(arena, &key->publicExponent, publicExponent);
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_keygen_from_primes(&p, &q, &e, 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;
MPINT_TO_SECITEM(&p, &key->prime1, arena);
MPINT_TO_SECITEM(&q, &key->prime2, arena);
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&e);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
if (rv && arena) {
PORT_FreeArena(arena, PR_TRUE);
key = NULL;
}
return key;
}
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;
}
PR_INIT_CLIST(&blindingParamsList.head);
return PR_SUCCESS;
}
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
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;
}
static SECStatus
get_blinding_params(RSAPrivateKey *key, mp_int *n, unsigned int modLen,
mp_int *f, mp_int *g)
{
SECStatus rv = SECSuccess;
mp_err err = MP_OKAY;
int cmp;
PRCList *el;
struct RSABlindingParamsStr *rsabp = NULL;
/* Init the list if neccessary (the init function is only called once!) */
if (blindingParamsList.lock == NULL) {
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
return SECFailure;
}
/* Acquire the list lock */
PZ_Lock(blindingParamsList.lock);
/* Walk the list looking for the private key */
for (el = PR_NEXT_LINK(&blindingParamsList.head);
el != &blindingParamsList.head;
el = PR_NEXT_LINK(el)) {
rsabp = (struct RSABlindingParamsStr *)el;
cmp = SECITEM_CompareItem(&rsabp->modulus, &key->modulus);
if (cmp == 0) {
/* Check the usage counter for the parameters */
if (--rsabp->counter <= 0) {
/* Regenerate the blinding parameters */
CHECK_SEC_OK( generate_blinding_params(rsabp, key, n, modLen) );
}
/* Return the parameters */
CHECK_MPI_OK( mp_copy(&rsabp->f, f) );
CHECK_MPI_OK( mp_copy(&rsabp->g, g) );
/* Now that the params are located, release the list lock. */
PZ_Unlock(blindingParamsList.lock); /* XXX when fails? */
return SECSuccess;
} else if (cmp > 0) {
/* The key is not in the list. Break to param creation. */
break;
}
}
/* At this point, the key is not in the list. el should point to the
** list element that this key should be inserted before. NOTE: the list
** lock is still held, so there cannot be a race condition here.
*/
rsabp = (struct RSABlindingParamsStr *)
PORT_ZAlloc(sizeof(struct RSABlindingParamsStr));
if (!rsabp) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
/* Initialize the list pointer for the element */
PR_INIT_CLIST(&rsabp->link);
/* Initialize the blinding parameters
** This ties up the list lock while doing some heavy, element-specific
** operations, but we don't want to insert the element until it is valid,
** which requires computing the blinding params. If this proves costly,
** it could be done after the list lock is released, and then if it fails
** the lock would have to be reobtained and the invalid element removed.
*/
rv = init_blinding_params(rsabp, key, n, modLen);
if (rv != SECSuccess) {
PORT_ZFree(rsabp, sizeof(struct RSABlindingParamsStr));
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);
/* Return the parameters */
CHECK_MPI_OK( mp_copy(&rsabp->f, f) );
CHECK_MPI_OK( mp_copy(&rsabp->g, g) );
/* Release the list lock */
PZ_Unlock(blindingParamsList.lock); /* XXX when fails? */
return SECSuccess;
cleanup:
/* It is possible to reach this after the lock is already released.
** Ignore the error in that case.
*/
PZ_Unlock(blindingParamsList.lock);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
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(&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(&n) );
CHECK_MPI_OK( mp_init(&p) );
CHECK_MPI_OK( mp_init(&q) );
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)
{
if (!coBPInit.initialized)
return;
while (!PR_CLIST_IS_EMPTY(&blindingParamsList.head))
{
struct RSABlindingParamsStr * rsabp = (struct RSABlindingParamsStr *)
PR_LIST_HEAD(&blindingParamsList.head);
PR_REMOVE_LINK(&rsabp->link);
mp_clear(&rsabp->f);
mp_clear(&rsabp->g);
SECITEM_FreeItem(&rsabp->modulus,PR_FALSE);
PORT_Free(rsabp);
}
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 parentForkedAfterC_Initialize;
/*
* Set fork flag so it can be tested in SKIP_AFTER_FORK on relevant platforms.
*/
void BL_SetForkState(PRBool forked)
{
parentForkedAfterC_Initialize = forked;
}