Merge remote-tracking branch 'trevp/pemfix' into trev-pem-fix
[openssl.git] / crypto / ec / ec2_smpl.c
index 980d396c81284003c0de58e58f2db8fbd41d9d01..9a9476f0c13c16a1a345e4a1563c93d156952ada 100644 (file)
@@ -9,25 +9,12 @@
  * The ECC Code is licensed pursuant to the OpenSSL open source
  * license provided below.
  *
- * In addition, Sun covenants to all licensees who provide a reciprocal
- * covenant with respect to their own patents if any, not to sue under
- * current and future patent claims necessarily infringed by the making,
- * using, practicing, selling, offering for sale and/or otherwise
- * disposing of the ECC Code as delivered hereunder (or portions thereof),
- * provided that such covenant shall not apply:
- *  1) for code that a licensee deletes from the ECC Code;
- *  2) separates from the ECC Code; or
- *  3) for infringements caused by:
- *       i) the modification of the ECC Code or
- *      ii) the combination of the ECC Code with other software or
- *          devices where such combination causes the infringement.
- *
  * The software is originally written by Sheueling Chang Shantz and
  * Douglas Stebila of Sun Microsystems Laboratories.
  *
  */
 /* ====================================================================
- * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
+ * 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
  *
  */
 
+#define OPENSSL_FIPSAPI
+
 #include <openssl/err.h>
 
 #include "ec_lcl.h"
 
+#ifndef OPENSSL_NO_EC2M
+
 
 const EC_METHOD *EC_GF2m_simple_method(void)
        {
        static const EC_METHOD ret = {
+               EC_FLAGS_DEFAULT_OCT,
                NID_X9_62_characteristic_two_field,
                ec_GF2m_simple_group_init,
                ec_GF2m_simple_group_finish,
@@ -106,19 +98,21 @@ const EC_METHOD *EC_GF2m_simple_method(void)
                0 /* get_Jprojective_coordinates_GFp */,
                ec_GF2m_simple_point_set_affine_coordinates,
                ec_GF2m_simple_point_get_affine_coordinates,
-               ec_GF2m_simple_set_compressed_coordinates,
-               ec_GF2m_simple_point2oct,
-               ec_GF2m_simple_oct2point,
+               0,0,0,
                ec_GF2m_simple_add,
                ec_GF2m_simple_dbl,
                ec_GF2m_simple_invert,
-               ec_GF2m_mont_mul,
-               ec_GF2m_mont_precompute_mult,
                ec_GF2m_simple_is_at_infinity,
                ec_GF2m_simple_is_on_curve,
                ec_GF2m_simple_cmp,
                ec_GF2m_simple_make_affine,
                ec_GF2m_simple_points_make_affine,
+
+               /* the following three method functions are defined in ec2_mult.c */
+               ec_GF2m_simple_mul,
+               ec_GF2m_precompute_mult,
+               ec_GF2m_have_precompute_mult,
+
                ec_GF2m_simple_field_mul,
                ec_GF2m_simple_field_sqr,
                ec_GF2m_simple_field_div,
@@ -166,6 +160,7 @@ void ec_GF2m_simple_group_clear_finish(EC_GROUP *group)
        group->poly[2] = 0;
        group->poly[3] = 0;
        group->poly[4] = 0;
+       group->poly[5] = -1;
        }
 
 
@@ -183,8 +178,9 @@ int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
        dest->poly[2] = src->poly[2];
        dest->poly[3] = src->poly[3];
        dest->poly[4] = src->poly[4];
-       bn_wexpand(&dest->a, (dest->poly[0] + BN_BITS2 - 1) / BN_BITS2);
-       bn_wexpand(&dest->b, (dest->poly[0] + BN_BITS2 - 1) / BN_BITS2);
+       dest->poly[5] = src->poly[5];
+       if (bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;
+       if (bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;
        for (i = dest->a.top; i < dest->a.dmax; i++) dest->a.d[i] = 0;
        for (i = dest->b.top; i < dest->b.dmax; i++) dest->b.d[i] = 0;
        return 1;
@@ -199,17 +195,21 @@ int ec_GF2m_simple_group_set_curve(EC_GROUP *group,
 
        /* group->field */
        if (!BN_copy(&group->field, p)) goto err;
-       i = BN_GF2m_poly2arr(&group->field, group->poly, 5);
-       if ((i != 5) && (i != 3)) goto err;
+       i = BN_GF2m_poly2arr(&group->field, group->poly, 6) - 1;
+       if ((i != 5) && (i != 3))
+               {
+               ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);
+               goto err;
+               }
 
        /* group->a */
        if (!BN_GF2m_mod_arr(&group->a, a, group->poly)) goto err;
-       bn_wexpand(&group->a, (group->poly[0] + BN_BITS2 - 1) / BN_BITS2);
+       if(bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;
        for (i = group->a.top; i < group->a.dmax; i++) group->a.d[i] = 0;
        
        /* group->b */
        if (!BN_GF2m_mod_arr(&group->b, b, group->poly)) goto err;
-       bn_wexpand(&group->b, (group->poly[0] + BN_BITS2 - 1) / BN_BITS2);
+       if(bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;
        for (i = group->b.top; i < group->b.dmax; i++) group->b.d[i] = 0;
                
        ret = 1;
@@ -230,16 +230,14 @@ int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
                if (!BN_copy(p, &group->field)) return 0;
                }
 
-       if (a != NULL || b != NULL)
+       if (a != NULL)
                {
-               if (a != NULL)
-                       {
-                       if (!BN_copy(a, &group->a)) goto err;
-                       }
-               if (b != NULL)
-                       {
-                       if (!BN_copy(b, &group->b)) goto err;
-                       }
+               if (!BN_copy(a, &group->a)) goto err;
+               }
+
+       if (b != NULL)
+               {
+               if (!BN_copy(b, &group->b)) goto err;
                }
        
        ret = 1;
@@ -288,7 +286,8 @@ int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
        ret = 1;
 
 err:
-       BN_CTX_end(ctx);
+       if (ctx != NULL)
+               BN_CTX_end(ctx);
        if (new_ctx != NULL)
                BN_CTX_free(new_ctx);
        return ret;
@@ -342,7 +341,8 @@ int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
 int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
        {
        point->Z_is_one = 0;
-       return (BN_zero(&point->Z));
+       BN_zero(&point->Z);
+       return 1;
        }
 
 
@@ -360,8 +360,11 @@ int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group, EC_POINT
                }
 
        if (!BN_copy(&point->X, x)) goto err;
+       BN_set_negative(&point->X, 0);
        if (!BN_copy(&point->Y, y)) goto err;
+       BN_set_negative(&point->Y, 0);
        if (!BN_copy(&point->Z, BN_value_one())) goto err;
+       BN_set_negative(&point->Z, 0);
        point->Z_is_one = 1;
        ret = 1;
 
@@ -392,10 +395,12 @@ int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group, const EC_
        if (x != NULL)
                {
                if (!BN_copy(x, &point->X)) goto err;
+               BN_set_negative(x, 0);
                }
        if (y != NULL)
                {
                if (!BN_copy(y, &point->Y)) goto err;
+               BN_set_negative(y, 0);
                }
        ret = 1;
                
@@ -403,274 +408,6 @@ int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group, const EC_
        return ret;
        }
 
-
-/* Include patented algorithms. */
-#include "ec2_smpt.c"
-
-
-/* Converts an EC_POINT to an octet string.  
- * If buf is NULL, the encoded length will be returned.
- * If the length len of buf is smaller than required an error will be returned.
- *
- * The point compression section of this function is patented by Certicom Corp. 
- * under US Patent 6,141,420.  Point compression is disabled by default and can 
- * be enabled by defining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at 
- * Configure-time.
- */
-size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
-       unsigned char *buf, size_t len, BN_CTX *ctx)
-       {
-       size_t ret;
-       BN_CTX *new_ctx = NULL;
-       int used_ctx = 0;
-       BIGNUM *x, *y, *yxi;
-       size_t field_len, i, skip;
-
-#ifndef OPENSSL_EC_BIN_PT_COMP
-       if ((form == POINT_CONVERSION_COMPRESSED) || (form == POINT_CONVERSION_HYBRID)) 
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_DISABLED);
-               goto err;
-               }
-#endif
-
-       if ((form != POINT_CONVERSION_COMPRESSED)
-               && (form != POINT_CONVERSION_UNCOMPRESSED)
-               && (form != POINT_CONVERSION_HYBRID))
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
-               goto err;
-               }
-
-       if (EC_POINT_is_at_infinity(group, point))
-               {
-               /* encodes to a single 0 octet */
-               if (buf != NULL)
-                       {
-                       if (len < 1)
-                               {
-                               ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
-                               return 0;
-                               }
-                       buf[0] = 0;
-                       }
-               return 1;
-               }
-
-
-       /* ret := required output buffer length */
-       field_len = (EC_GROUP_get_degree(group) + 7) / 8;
-       ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
-       /* if 'buf' is NULL, just return required length */
-       if (buf != NULL)
-               {
-               if (len < ret)
-                       {
-                       ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
-                       goto err;
-                       }
-
-               if (ctx == NULL)
-                       {
-                       ctx = new_ctx = BN_CTX_new();
-                       if (ctx == NULL)
-                               return 0;
-                       }
-
-               BN_CTX_start(ctx);
-               used_ctx = 1;
-               x = BN_CTX_get(ctx);
-               y = BN_CTX_get(ctx);
-               yxi = BN_CTX_get(ctx);
-               if (yxi == NULL) goto err;
-
-               if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-
-               buf[0] = form;
-#ifdef OPENSSL_EC_BIN_PT_COMP
-               if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x))
-                       {
-                       if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
-                       if (BN_is_odd(yxi)) buf[0]++;
-                       }
-#endif
-
-               i = 1;
-               
-               skip = field_len - BN_num_bytes(x);
-               if (skip > field_len)
-                       {
-                       ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                       goto err;
-                       }
-               while (skip > 0)
-                       {
-                       buf[i++] = 0;
-                       skip--;
-                       }
-               skip = BN_bn2bin(x, buf + i);
-               i += skip;
-               if (i != 1 + field_len)
-                       {
-                       ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                       goto err;
-                       }
-
-               if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
-                       {
-                       skip = field_len - BN_num_bytes(y);
-                       if (skip > field_len)
-                               {
-                               ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                               goto err;
-                               }
-                       while (skip > 0)
-                               {
-                               buf[i++] = 0;
-                               skip--;
-                               }
-                       skip = BN_bn2bin(y, buf + i);
-                       i += skip;
-                       }
-
-               if (i != ret)
-                       {
-                       ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                       goto err;
-                       }
-               }
-       
-       if (used_ctx)
-               BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-
- err:
-       if (used_ctx)
-               BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return 0;
-       }
-
-
-/* Converts an octet string representation to an EC_POINT. 
- * Note that the simple implementation only uses affine coordinates.
- */
-int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
-       const unsigned char *buf, size_t len, BN_CTX *ctx)
-       {
-       point_conversion_form_t form;
-       int y_bit;
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *x, *y, *yxi;
-       size_t field_len, enc_len;
-       int ret = 0;
-
-       if (len == 0)
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
-               return 0;
-               }
-       form = buf[0];
-       y_bit = form & 1;
-       form = form & ~1;
-       if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
-               && (form != POINT_CONVERSION_UNCOMPRESSED)
-               && (form != POINT_CONVERSION_HYBRID))
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               return 0;
-               }
-       if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               return 0;
-               }
-
-       if (form == 0)
-               {
-               if (len != 1)
-                       {
-                       ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-                       return 0;
-                       }
-
-               return EC_POINT_set_to_infinity(group, point);
-               }
-       
-       field_len = (EC_GROUP_get_degree(group) + 7) / 8;
-       enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
-       if (len != enc_len)
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               return 0;
-               }
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       BN_CTX_start(ctx);
-       x = BN_CTX_get(ctx);
-       y = BN_CTX_get(ctx);
-       yxi = BN_CTX_get(ctx);
-       if (yxi == NULL) goto err;
-
-       if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
-       if (BN_ucmp(x, &group->field) >= 0)
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               goto err;
-               }
-
-       if (form == POINT_CONVERSION_COMPRESSED)
-               {
-               if (!EC_POINT_set_compressed_coordinates_GF2m(group, point, x, y_bit, ctx)) goto err;
-               }
-       else
-               {
-               if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
-               if (BN_ucmp(y, &group->field) >= 0)
-                       {
-                       ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-                       goto err;
-                       }
-               if (form == POINT_CONVERSION_HYBRID)
-                       {
-                       if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
-                       if (y_bit != BN_is_odd(yxi))
-                               {
-                               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-                               goto err;
-                               }
-                       }
-
-               if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-               }
-       
-       if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
-               {
-               ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
-               goto err;
-               }
-
-       ret = 1;
-       
- err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
 /* Computes a + b and stores the result in r.  r could be a or b, a could be b.
  * Uses algorithm A.10.2 of IEEE P1363.
  */
@@ -806,15 +543,20 @@ int ec_GF2m_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
  */
 int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
        {
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *rh, *lh, *tmp1;
        int ret = -1;
+       BN_CTX *new_ctx = NULL;
+       BIGNUM *lh, *y2;
+       int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+       int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
 
        if (EC_POINT_is_at_infinity(group, point))
                return 1;
-       
+
+       field_mul = group->meth->field_mul;
+       field_sqr = group->meth->field_sqr;     
+
        /* only support affine coordinates */
-       if (!point->Z_is_one) goto err;
+       if (!point->Z_is_one) return -1;
 
        if (ctx == NULL)
                {
@@ -824,37 +566,23 @@ int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_
                }
 
        BN_CTX_start(ctx);
-       rh = BN_CTX_get(ctx);
+       y2 = BN_CTX_get(ctx);
        lh = BN_CTX_get(ctx);
-       tmp1 = BN_CTX_get(ctx);
-       if (tmp1 == NULL) goto err;
+       if (lh == NULL) goto err;
 
        /* We have a curve defined by a Weierstrass equation
         *      y^2 + x*y = x^3 + a*x^2 + b.
-        * To test this, we add up the right-hand side in 'rh'
-        * and the left-hand side in 'lh'.
+        *  <=> x^3 + a*x^2 + x*y + b + y^2 = 0
+        *  <=> ((x + a) * x + y ) * x + b + y^2 = 0
         */
-
-       /* rh := X^3 */
-       if (!group->meth->field_sqr(group, tmp1, &point->X, ctx)) goto err;
-       if (!group->meth->field_mul(group, rh, tmp1, &point->X, ctx)) goto err;
-
-       /* rh := rh + a*X^2 */
-       if (!group->meth->field_mul(group, tmp1, tmp1, &group->a, ctx)) goto err;
-       if (!BN_GF2m_add(rh, rh, tmp1)) goto err;
-
-       /* rh := rh + b */
-       if (!BN_GF2m_add(rh, rh, &group->b)) goto err;
-
-       /* lh := Y^2 */
-       if (!group->meth->field_sqr(group, lh, &point->Y, ctx)) goto err;
-
-       /* lh := lh + x*y */
-       if (!group->meth->field_mul(group, tmp1, &point->X, &point->Y, ctx)) goto err;
-       if (!BN_GF2m_add(lh, lh, tmp1)) goto err;
-
-       ret = (0 == BN_GF2m_cmp(lh, rh));
-
+       if (!BN_GF2m_add(lh, &point->X, &group->a)) goto err;
+       if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;
+       if (!BN_GF2m_add(lh, lh, &point->Y)) goto err;
+       if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;
+       if (!BN_GF2m_add(lh, lh, &group->b)) goto err;
+       if (!field_sqr(group, y2, &point->Y, ctx)) goto err;
+       if (!BN_GF2m_add(lh, lh, y2)) goto err;
+       ret = BN_is_zero(lh);
  err:
        if (ctx) BN_CTX_end(ctx);
        if (new_ctx) BN_CTX_free(new_ctx);
@@ -878,6 +606,9 @@ int ec_GF2m_simple_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT
                {
                return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
                }
+
+       if (EC_POINT_is_at_infinity(group, b))
+               return 1;
        
        if (a->Z_is_one && b->Z_is_one)
                {
@@ -978,3 +709,5 @@ int ec_GF2m_simple_field_div(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
        {
        return BN_GF2m_mod_div(r, a, b, &group->field, ctx);
        }
+
+#endif