protect BN_BLINDING_invert with a write lock and BN_BLINDING_convert
[openssl.git] / crypto / rsa / rsa_eay.c
index 738ea0be71c3f932f1cc5811dfac32b6fb52e805..56da944845996ee6655028a2e7715a68599504a1 100644 (file)
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2005 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
+ *    openssl-core@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 <stdio.h>
 #include "cryptlib.h"
@@ -230,9 +283,9 @@ static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,
        else
                {
                int ret;
-               CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
+               CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
                ret = BN_BLINDING_convert_ex(f, r, b, ctx);
-               CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
+               CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
                return ret;
                }
 }
@@ -245,9 +298,9 @@ static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
        else
                {
                int ret;
-               CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
+               CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
                ret = BN_BLINDING_invert_ex(f, r, b, ctx);
-               CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
+               CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
                return ret;
                }
 }
@@ -256,7 +309,7 @@ static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
             unsigned char *to, RSA *rsa, int padding)
        {
-       BIGNUM *f, *ret, *br;
+       BIGNUM *f, *ret, *br, *res;
        int i,j,k,num=0,r= -1;
        unsigned char *buf=NULL;
        BN_CTX *ctx=NULL;
@@ -281,6 +334,9 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
        case RSA_PKCS1_PADDING:
                i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
                break;
+       case RSA_X931_PADDING:
+               i=RSA_padding_add_X931(buf,num,from,flen);
+               break;
        case RSA_NO_PADDING:
                i=RSA_padding_add_none(buf,num,from,flen);
                break;
@@ -320,11 +376,26 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
                (rsa->dmp1 != NULL) &&
                (rsa->dmq1 != NULL) &&
                (rsa->iqmp != NULL)) )
-               { if (!rsa->meth->rsa_mod_exp(ret,f,rsa,ctx)) goto err; }
+               { 
+               if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
+               }
        else
                {
+               BIGNUM local_d;
+               BIGNUM *d = NULL;
+               
+               if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
+                       {
+                       BN_init(&local_d);
+                       d = &local_d;
+                       BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
+                       }
+               else
+                       d = rsa->d;
+
                MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
-               if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx,
+
+               if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
                                rsa->_method_mod_n)) goto err;
                }
 
@@ -332,10 +403,21 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
                if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
                        goto err;
 
+       if (padding == RSA_X931_PADDING)
+               {
+               BN_sub(f, rsa->n, ret);
+               if (BN_cmp(ret, f))
+                       res = f;
+               else
+                       res = ret;
+               }
+       else
+               res = ret;
+
        /* put in leading 0 bytes if the number is less than the
         * length of the modulus */
-       j=BN_num_bytes(ret);
-       i=BN_bn2bin(ret,&(to[num-j]));
+       j=BN_num_bytes(res);
+       i=BN_bn2bin(res,&(to[num-j]));
        for (k=0; k<(num-i); k++)
                to[k]=0;
 
@@ -400,7 +482,7 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
                blinding = rsa_get_blinding(rsa, &br, &local_blinding, ctx);
                if (blinding == NULL)
                        {
-                       RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
+                       RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
                        goto err;
                        }
                }
@@ -416,13 +498,26 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
                (rsa->dmp1 != NULL) &&
                (rsa->dmq1 != NULL) &&
                (rsa->iqmp != NULL)) )
-               { if (!rsa->meth->rsa_mod_exp(ret,f,rsa,ctx)) goto err; }
+               {
+               if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
+               }
        else
                {
+               BIGNUM local_d;
+               BIGNUM *d = NULL;
+               
+               if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
+                       {
+                       d = &local_d;
+                       BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
+                       }
+               else
+                       d = rsa->d;
+
                MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
-               if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx,
+               if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
                                rsa->_method_mod_n))
-                       goto err;
+                 goto err;
                }
 
        if (blinding)
@@ -512,6 +607,9 @@ static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
        if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
                rsa->_method_mod_n)) goto err;
 
+       if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
+               BN_sub(ret, rsa->n, ret);
+
        p=buf;
        i=BN_bn2bin(ret,p);
 
@@ -520,6 +618,9 @@ static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
        case RSA_PKCS1_PADDING:
                r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
                break;
+       case RSA_X931_PADDING:
+               r=RSA_padding_check_X931(to,num,buf,i,num);
+               break;
        case RSA_NO_PADDING:
                r=RSA_padding_check_none(to,num,buf,i,num);
                break;
@@ -547,6 +648,8 @@ err:
 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
        {
        BIGNUM *r1,*m1,*vrfy;
+       BIGNUM local_dmp1, local_dmq1;
+       BIGNUM *dmp1, *dmq1;
        int ret=0;
 
        BN_CTX_start(ctx);
@@ -559,11 +662,25 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
        MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
 
        if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
-       if (!rsa->meth->bn_mod_exp(m1,r1,rsa->dmq1,rsa->q,ctx,
+       if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
+               {
+               dmq1 = &local_dmq1;
+               BN_with_flags(dmq1, rsa->dmq1, BN_FLG_EXP_CONSTTIME);
+               }
+       else
+               dmq1 = rsa->dmq1;
+       if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
                rsa->_method_mod_q)) goto err;
 
        if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
-       if (!rsa->meth->bn_mod_exp(r0,r1,rsa->dmp1,rsa->p,ctx,
+       if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
+               {
+               dmp1 = &local_dmp1;
+               BN_with_flags(dmp1, rsa->dmp1, BN_FLG_EXP_CONSTTIME);
+               }
+       else
+               dmp1 = rsa->dmp1;
+       if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
                rsa->_method_mod_p)) goto err;
 
        if (!BN_sub(r0,r0,m1)) goto err;
@@ -598,11 +715,24 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                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. */
-                       if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,
-                                       rsa->_method_mod_n)) goto err;
+
+                       BIGNUM local_d;
+                       BIGNUM *d = NULL;
+               
+                       if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
+                               {
+                               d = &local_d;
+                               BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
+                               }
+                       else
+                               d = rsa->d;
+                       if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
+                                                  rsa->_method_mod_n)) goto err;
+                       }
                }
        ret=1;
 err: