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-rw-r--r--openssl/crypto/engine/eng_rsax.c668
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diff --git a/openssl/crypto/engine/eng_rsax.c b/openssl/crypto/engine/eng_rsax.c
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+++ b/openssl/crypto/engine/eng_rsax.c
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+/* crypto/engine/eng_rsax.c */
+/* Copyright (c) 2010-2010 Intel Corp.
+ * Author: Vinodh.Gopal@intel.com
+ * Jim Guilford
+ * Erdinc.Ozturk@intel.com
+ * Maxim.Perminov@intel.com
+ * Ying.Huang@intel.com
+ *
+ * More information about algorithm used can be found at:
+ * http://www.cse.buffalo.edu/srds2009/escs2009_submission_Gopal.pdf
+ */
+/* ====================================================================
+ * Copyright (c) 1999-2001 The OpenSSL Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ */
+
+#include <openssl/opensslconf.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <openssl/crypto.h>
+#include <openssl/buffer.h>
+#include <openssl/engine.h>
+#ifndef OPENSSL_NO_RSA
+#include <openssl/rsa.h>
+#endif
+#include <openssl/bn.h>
+#include <openssl/err.h>
+
+/* RSAX is available **ONLY* on x86_64 CPUs */
+#undef COMPILE_RSAX
+
+#if (defined(__x86_64) || defined(__x86_64__) || \
+ defined(_M_AMD64) || defined (_M_X64)) && !defined(OPENSSL_NO_ASM)
+#define COMPILE_RSAX
+static ENGINE *ENGINE_rsax (void);
+#endif
+
+void ENGINE_load_rsax (void)
+ {
+/* On non-x86 CPUs it just returns. */
+#ifdef COMPILE_RSAX
+ ENGINE *toadd = ENGINE_rsax();
+ if(!toadd) return;
+ ENGINE_add(toadd);
+ ENGINE_free(toadd);
+ ERR_clear_error();
+#endif
+ }
+
+#ifdef COMPILE_RSAX
+#define E_RSAX_LIB_NAME "rsax engine"
+
+static int e_rsax_destroy(ENGINE *e);
+static int e_rsax_init(ENGINE *e);
+static int e_rsax_finish(ENGINE *e);
+static int e_rsax_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void));
+
+#ifndef OPENSSL_NO_RSA
+/* RSA stuff */
+static int e_rsax_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa, BN_CTX *ctx);
+static int e_rsax_rsa_finish(RSA *r);
+#endif
+
+static const ENGINE_CMD_DEFN e_rsax_cmd_defns[] = {
+ {0, NULL, NULL, 0}
+ };
+
+#ifndef OPENSSL_NO_RSA
+/* Our internal RSA_METHOD that we provide pointers to */
+static RSA_METHOD e_rsax_rsa =
+ {
+ "Intel RSA-X method",
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ e_rsax_rsa_mod_exp,
+ NULL,
+ NULL,
+ e_rsax_rsa_finish,
+ RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE,
+ NULL,
+ NULL,
+ NULL
+ };
+#endif
+
+/* Constants used when creating the ENGINE */
+static const char *engine_e_rsax_id = "rsax";
+static const char *engine_e_rsax_name = "RSAX engine support";
+
+/* This internal function is used by ENGINE_rsax() */
+static int bind_helper(ENGINE *e)
+ {
+#ifndef OPENSSL_NO_RSA
+ const RSA_METHOD *meth1;
+#endif
+ if(!ENGINE_set_id(e, engine_e_rsax_id) ||
+ !ENGINE_set_name(e, engine_e_rsax_name) ||
+#ifndef OPENSSL_NO_RSA
+ !ENGINE_set_RSA(e, &e_rsax_rsa) ||
+#endif
+ !ENGINE_set_destroy_function(e, e_rsax_destroy) ||
+ !ENGINE_set_init_function(e, e_rsax_init) ||
+ !ENGINE_set_finish_function(e, e_rsax_finish) ||
+ !ENGINE_set_ctrl_function(e, e_rsax_ctrl) ||
+ !ENGINE_set_cmd_defns(e, e_rsax_cmd_defns))
+ return 0;
+
+#ifndef OPENSSL_NO_RSA
+ meth1 = RSA_PKCS1_SSLeay();
+ e_rsax_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
+ e_rsax_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
+ e_rsax_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
+ e_rsax_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
+ e_rsax_rsa.bn_mod_exp = meth1->bn_mod_exp;
+#endif
+ return 1;
+ }
+
+static ENGINE *ENGINE_rsax(void)
+ {
+ ENGINE *ret = ENGINE_new();
+ if(!ret)
+ return NULL;
+ if(!bind_helper(ret))
+ {
+ ENGINE_free(ret);
+ return NULL;
+ }
+ return ret;
+ }
+
+#ifndef OPENSSL_NO_RSA
+/* Used to attach our own key-data to an RSA structure */
+static int rsax_ex_data_idx = -1;
+#endif
+
+static int e_rsax_destroy(ENGINE *e)
+ {
+ return 1;
+ }
+
+/* (de)initialisation functions. */
+static int e_rsax_init(ENGINE *e)
+ {
+#ifndef OPENSSL_NO_RSA
+ if (rsax_ex_data_idx == -1)
+ rsax_ex_data_idx = RSA_get_ex_new_index(0,
+ NULL,
+ NULL, NULL, NULL);
+#endif
+ if (rsax_ex_data_idx == -1)
+ return 0;
+ return 1;
+ }
+
+static int e_rsax_finish(ENGINE *e)
+ {
+ return 1;
+ }
+
+static int e_rsax_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
+ {
+ int to_return = 1;
+
+ switch(cmd)
+ {
+ /* The command isn't understood by this engine */
+ default:
+ to_return = 0;
+ break;
+ }
+
+ return to_return;
+ }
+
+
+#ifndef OPENSSL_NO_RSA
+
+#ifdef _WIN32
+typedef unsigned __int64 UINT64;
+#else
+typedef unsigned long long UINT64;
+#endif
+typedef unsigned short UINT16;
+
+/* Table t is interleaved in the following manner:
+ * The order in memory is t[0][0], t[0][1], ..., t[0][7], t[1][0], ...
+ * A particular 512-bit value is stored in t[][index] rather than the more
+ * normal t[index][]; i.e. the qwords of a particular entry in t are not
+ * adjacent in memory
+ */
+
+/* Init BIGNUM b from the interleaved UINT64 array */
+static int interleaved_array_to_bn_512(BIGNUM* b, UINT64 *array);
+
+/* Extract array elements from BIGNUM b
+ * To set the whole array from b, call with n=8
+ */
+static int bn_extract_to_array_512(const BIGNUM* b, unsigned int n, UINT64 *array);
+
+struct mod_ctx_512 {
+ UINT64 t[8][8];
+ UINT64 m[8];
+ UINT64 m1[8]; /* 2^278 % m */
+ UINT64 m2[8]; /* 2^640 % m */
+ UINT64 k1[2]; /* (- 1/m) % 2^128 */
+};
+
+static int mod_exp_pre_compute_data_512(UINT64 *m, struct mod_ctx_512 *data);
+
+void mod_exp_512(UINT64 *result, /* 512 bits, 8 qwords */
+ UINT64 *g, /* 512 bits, 8 qwords */
+ UINT64 *exp, /* 512 bits, 8 qwords */
+ struct mod_ctx_512 *data);
+
+typedef struct st_e_rsax_mod_ctx
+{
+ UINT64 type;
+ union {
+ struct mod_ctx_512 b512;
+ } ctx;
+
+} E_RSAX_MOD_CTX;
+
+static E_RSAX_MOD_CTX *e_rsax_get_ctx(RSA *rsa, int idx, BIGNUM* m)
+{
+ E_RSAX_MOD_CTX *hptr;
+
+ if (idx < 0 || idx > 2)
+ return NULL;
+
+ hptr = RSA_get_ex_data(rsa, rsax_ex_data_idx);
+ if (!hptr) {
+ hptr = OPENSSL_malloc(3*sizeof(E_RSAX_MOD_CTX));
+ if (!hptr) return NULL;
+ hptr[2].type = hptr[1].type= hptr[0].type = 0;
+ RSA_set_ex_data(rsa, rsax_ex_data_idx, hptr);
+ }
+
+ if (hptr[idx].type == (UINT64)BN_num_bits(m))
+ return hptr+idx;
+
+ if (BN_num_bits(m) == 512) {
+ UINT64 _m[8];
+ bn_extract_to_array_512(m, 8, _m);
+ memset( &hptr[idx].ctx.b512, 0, sizeof(struct mod_ctx_512));
+ mod_exp_pre_compute_data_512(_m, &hptr[idx].ctx.b512);
+ }
+
+ hptr[idx].type = BN_num_bits(m);
+ return hptr+idx;
+}
+
+static int e_rsax_rsa_finish(RSA *rsa)
+ {
+ E_RSAX_MOD_CTX *hptr = RSA_get_ex_data(rsa, rsax_ex_data_idx);
+ if(hptr)
+ {
+ OPENSSL_free(hptr);
+ RSA_set_ex_data(rsa, rsax_ex_data_idx, NULL);
+ }
+ if (rsa->_method_mod_n)
+ BN_MONT_CTX_free(rsa->_method_mod_n);
+ if (rsa->_method_mod_p)
+ BN_MONT_CTX_free(rsa->_method_mod_p);
+ if (rsa->_method_mod_q)
+ BN_MONT_CTX_free(rsa->_method_mod_q);
+ return 1;
+ }
+
+
+static int e_rsax_bn_mod_exp(BIGNUM *r, const BIGNUM *g, const BIGNUM *e,
+ const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont, E_RSAX_MOD_CTX* rsax_mod_ctx )
+{
+ if (rsax_mod_ctx && BN_get_flags(e, BN_FLG_CONSTTIME) != 0) {
+ if (BN_num_bits(m) == 512) {
+ UINT64 _r[8];
+ UINT64 _g[8];
+ UINT64 _e[8];
+
+ /* Init the arrays from the BIGNUMs */
+ bn_extract_to_array_512(g, 8, _g);
+ bn_extract_to_array_512(e, 8, _e);
+
+ mod_exp_512(_r, _g, _e, &rsax_mod_ctx->ctx.b512);
+ /* Return the result in the BIGNUM */
+ interleaved_array_to_bn_512(r, _r);
+ return 1;
+ }
+ }
+
+ return BN_mod_exp_mont(r, g, e, m, ctx, in_mont);
+}
+
+/* Declares for the Intel CIAP 512-bit / CRT / 1024 bit RSA modular
+ * exponentiation routine precalculations and a structure to hold the
+ * necessary values. These files are meant to live in crypto/rsa/ in
+ * the target openssl.
+ */
+
+/*
+ * Local method: extracts a piece from a BIGNUM, to fit it into
+ * an array. Call with n=8 to extract an entire 512-bit BIGNUM
+ */
+static int bn_extract_to_array_512(const BIGNUM* b, unsigned int n, UINT64 *array)
+{
+ int i;
+ UINT64 tmp;
+ unsigned char bn_buff[64];
+ memset(bn_buff, 0, 64);
+ if (BN_num_bytes(b) > 64) {
+ printf ("Can't support this byte size\n");
+ return 0; }
+ if (BN_num_bytes(b)!=0) {
+ if (!BN_bn2bin(b, bn_buff+(64-BN_num_bytes(b)))) {
+ printf ("Error's in bn2bin\n");
+ /* We have to error, here */
+ return 0; } }
+ while (n-- > 0) {
+ array[n] = 0;
+ for (i=7; i>=0; i--) {
+ tmp = bn_buff[63-(n*8+i)];
+ array[n] |= tmp << (8*i); } }
+ return 1;
+}
+
+/* Init a 512-bit BIGNUM from the UINT64*_ (8 * 64) interleaved array */
+static int interleaved_array_to_bn_512(BIGNUM* b, UINT64 *array)
+{
+ unsigned char tmp[64];
+ int n=8;
+ int i;
+ while (n-- > 0) {
+ for (i = 7; i>=0; i--) {
+ tmp[63-(n*8+i)] = (unsigned char)(array[n]>>(8*i)); } }
+ BN_bin2bn(tmp, 64, b);
+ return 0;
+}
+
+
+/* The main 512bit precompute call */
+static int mod_exp_pre_compute_data_512(UINT64 *m, struct mod_ctx_512 *data)
+ {
+ BIGNUM two_768, two_640, two_128, two_512, tmp, _m, tmp2;
+
+ /* We need a BN_CTX for the modulo functions */
+ BN_CTX* ctx;
+ /* Some tmps */
+ UINT64 _t[8];
+ int i, j, ret = 0;
+
+ /* Init _m with m */
+ BN_init(&_m);
+ interleaved_array_to_bn_512(&_m, m);
+ memset(_t, 0, 64);
+
+ /* Inits */
+ BN_init(&two_768);
+ BN_init(&two_640);
+ BN_init(&two_128);
+ BN_init(&two_512);
+ BN_init(&tmp);
+ BN_init(&tmp2);
+
+ /* Create our context */
+ if ((ctx=BN_CTX_new()) == NULL) { goto err; }
+ BN_CTX_start(ctx);
+
+ /*
+ * For production, if you care, these only need to be set once,
+ * and may be made constants.
+ */
+ BN_lshift(&two_768, BN_value_one(), 768);
+ BN_lshift(&two_640, BN_value_one(), 640);
+ BN_lshift(&two_128, BN_value_one(), 128);
+ BN_lshift(&two_512, BN_value_one(), 512);
+
+ if (0 == (m[7] & 0x8000000000000000)) {
+ exit(1);
+ }
+ if (0 == (m[0] & 0x1)) { /* Odd modulus required for Mont */
+ exit(1);
+ }
+
+ /* Precompute m1 */
+ BN_mod(&tmp, &two_768, &_m, ctx);
+ if (!bn_extract_to_array_512(&tmp, 8, &data->m1[0])) {
+ goto err; }
+
+ /* Precompute m2 */
+ BN_mod(&tmp, &two_640, &_m, ctx);
+ if (!bn_extract_to_array_512(&tmp, 8, &data->m2[0])) {
+ goto err;
+ }
+
+ /*
+ * Precompute k1, a 128b number = ((-1)* m-1 ) mod 2128; k1 should
+ * be non-negative.
+ */
+ BN_mod_inverse(&tmp, &_m, &two_128, ctx);
+ if (!BN_is_zero(&tmp)) { BN_sub(&tmp, &two_128, &tmp); }
+ if (!bn_extract_to_array_512(&tmp, 2, &data->k1[0])) {
+ goto err; }
+
+ /* Precompute t */
+ for (i=0; i<8; i++) {
+ BN_zero(&tmp);
+ if (i & 1) { BN_add(&tmp, &two_512, &tmp); }
+ if (i & 2) { BN_add(&tmp, &two_512, &tmp); }
+ if (i & 4) { BN_add(&tmp, &two_640, &tmp); }
+
+ BN_nnmod(&tmp2, &tmp, &_m, ctx);
+ if (!bn_extract_to_array_512(&tmp2, 8, _t)) {
+ goto err; }
+ for (j=0; j<8; j++) data->t[j][i] = _t[j]; }
+
+ /* Precompute m */
+ for (i=0; i<8; i++) {
+ data->m[i] = m[i]; }
+
+ ret = 1;
+
+err:
+ /* Cleanup */
+ if (ctx != NULL) {
+ BN_CTX_end(ctx); BN_CTX_free(ctx); }
+ BN_free(&two_768);
+ BN_free(&two_640);
+ BN_free(&two_128);
+ BN_free(&two_512);
+ BN_free(&tmp);
+ BN_free(&tmp2);
+ BN_free(&_m);
+
+ return ret;
+}
+
+
+static int e_rsax_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
+ {
+ BIGNUM *r1,*m1,*vrfy;
+ BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
+ BIGNUM *dmp1,*dmq1,*c,*pr1;
+ int ret=0;
+
+ BN_CTX_start(ctx);
+ r1 = BN_CTX_get(ctx);
+ m1 = BN_CTX_get(ctx);
+ vrfy = BN_CTX_get(ctx);
+
+ {
+ BIGNUM local_p, local_q;
+ BIGNUM *p = NULL, *q = NULL;
+ int error = 0;
+
+ /* Make sure BN_mod_inverse in Montgomery
+ * intialization uses the BN_FLG_CONSTTIME flag
+ * (unless RSA_FLAG_NO_CONSTTIME is set)
+ */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ BN_init(&local_p);
+ p = &local_p;
+ BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
+
+ BN_init(&local_q);
+ q = &local_q;
+ BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
+ }
+ else
+ {
+ p = rsa->p;
+ q = rsa->q;
+ }
+
+ if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
+ {
+ if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
+ error = 1;
+ if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
+ error = 1;
+ }
+
+ /* clean up */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ BN_free(&local_p);
+ BN_free(&local_q);
+ }
+ if ( error )
+ goto err;
+ }
+
+ if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
+ if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
+ goto err;
+
+ /* compute I mod q */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ c = &local_c;
+ BN_with_flags(c, I, BN_FLG_CONSTTIME);
+ if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
+ }
+
+ /* compute r1^dmq1 mod q */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ dmq1 = &local_dmq1;
+ BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
+ }
+ else
+ dmq1 = rsa->dmq1;
+
+ if (!e_rsax_bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
+ rsa->_method_mod_q, e_rsax_get_ctx(rsa, 0, rsa->q) )) goto err;
+
+ /* compute I mod p */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ c = &local_c;
+ BN_with_flags(c, I, BN_FLG_CONSTTIME);
+ if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
+ }
+
+ /* compute r1^dmp1 mod p */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ dmp1 = &local_dmp1;
+ BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
+ }
+ else
+ dmp1 = rsa->dmp1;
+
+ if (!e_rsax_bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
+ rsa->_method_mod_p, e_rsax_get_ctx(rsa, 1, rsa->p) )) goto err;
+
+ if (!BN_sub(r0,r0,m1)) goto err;
+ /* This will help stop the size of r0 increasing, which does
+ * affect the multiply if it optimised for a power of 2 size */
+ if (BN_is_negative(r0))
+ if (!BN_add(r0,r0,rsa->p)) goto err;
+
+ if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
+
+ /* Turn BN_FLG_CONSTTIME flag on before division operation */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ pr1 = &local_r1;
+ BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
+ }
+ else
+ pr1 = r1;
+ if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
+
+ /* If p < q it is occasionally possible for the correction of
+ * adding 'p' if r0 is negative above to leave the result still
+ * negative. This can break the private key operations: the following
+ * second correction should *always* correct this rare occurrence.
+ * This will *never* happen with OpenSSL generated keys because
+ * they ensure p > q [steve]
+ */
+ if (BN_is_negative(r0))
+ if (!BN_add(r0,r0,rsa->p)) goto err;
+ if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
+ if (!BN_add(r0,r1,m1)) goto err;
+
+ if (rsa->e && rsa->n)
+ {
+ if (!e_rsax_bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n, e_rsax_get_ctx(rsa, 2, rsa->n) ))
+ goto err;
+
+ /* If 'I' was greater than (or equal to) rsa->n, the operation
+ * will be equivalent to using 'I mod n'. However, the result of
+ * the verify will *always* be less than 'n' so we don't check
+ * for absolute equality, just congruency. */
+ if (!BN_sub(vrfy, vrfy, I)) goto err;
+ if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
+ if (BN_is_negative(vrfy))
+ if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
+ if (!BN_is_zero(vrfy))
+ {
+ /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
+ * miscalculated CRT output, just do a raw (slower)
+ * mod_exp and return that instead. */
+
+ BIGNUM local_d;
+ BIGNUM *d = NULL;
+
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
+ {
+ d = &local_d;
+ BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
+ }
+ else
+ d = rsa->d;
+ if (!e_rsax_bn_mod_exp(r0,I,d,rsa->n,ctx,
+ rsa->_method_mod_n, e_rsax_get_ctx(rsa, 2, rsa->n) )) goto err;
+ }
+ }
+ ret=1;
+
+err:
+ BN_CTX_end(ctx);
+
+ return ret;
+ }
+#endif /* !OPENSSL_NO_RSA */
+#endif /* !COMPILE_RSAX */