diff options
author | cvs2hg <devnull@localhost> | 2001-04-12 20:23:43 +0000 |
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committer | cvs2hg <devnull@localhost> | 2001-04-12 20:23:43 +0000 |
commit | 276965998e7ea707570c06e5d1faeddc01a42ec8 (patch) | |
tree | 50394e8becefa80c1be428065a0f2b04b3fdbdd7 | |
parent | 4991ba3e01ae8033f3bdd65a60bc48095194e7fe (diff) | |
download | nss-hg-276965998e7ea707570c06e5d1faeddc01a42ec8.tar.gz |
fixup commit for branch 'NSS_3_2_BRANCH'
-rw-r--r-- | security/nss/lib/freebl/rsa.c | 694 |
1 files changed, 694 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/rsa.c b/security/nss/lib/freebl/rsa.c new file mode 100644 index 000000000..e91ed3c22 --- /dev/null +++ b/security/nss/lib/freebl/rsa.c @@ -0,0 +1,694 @@ +/* + * 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 Netscape are + * Copyright (C) 1994-2000 Netscape Communications Corporation. All + * Rights Reserved. + * + * Contributor(s): + * + * Alternatively, the contents of this file may be used under the + * terms of the GNU General Public License Version 2 or later (the + * "GPL"), in which case the provisions of the GPL are applicable + * instead of those above. If you wish to allow use of your + * version of this file only under the terms of the GPL and not to + * allow others to use your version of this file under the MPL, + * indicate your decision by deleting the provisions above and + * replace them with the notice and other provisions required by + * the GPL. If you do not delete the provisions above, a recipient + * may use your version of this file under either the MPL or the + * GPL. + * + */ + +/* + * RSA key generation, public key op, private key op. + * + * $Id$ + */ + +#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" + +/* +** 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 + +/* +** 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) { + 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; + 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); + /* 1. Obtain public key (n, e) */ + SECITEM_TO_MPINT(key->modulus, &n); + SECITEM_TO_MPINT(key->publicExponent, &e); + /* 2. 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_PrivateKeyOp(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_PrivateKeyOpCRT(RSAPrivateKey *key, mp_int *m, mp_int *c, + unsigned int modLen) +{ + mp_int p, q, d_p, d_q, qInv; + mp_int m1, m2, b2, 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(&b2) = 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(&b2) ); + 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_p = 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(&b2); + mp_clear(&h); + mp_clear(&ctmp); + 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) { + if (PR_CallOnce(&coBPInit, init_blinding_params_list) != PR_SUCCESS) { + 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. +*/ +SECStatus +RSA_PrivateKeyOp(RSAPrivateKey *key, + unsigned char *output, + const unsigned char *input) +{ + unsigned int modLen; + unsigned int offset; + SECStatus rv; + 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_PrivateKeyOp(key, &m, &c, &n, modLen) ); + } else { + CHECK_SEC_OK( rsa_PrivateKeyOpCRT(key, &m, &c, modLen) ); + } + /* 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; +} |