knf approximation

1 files changed, 142 insertions, 169 deletions

diff --git a/src/lib/libcrypto/ec/ec2_oct.c b/src/lib/libcrypto/ec/ec2_oct.c
index f1d75e5ddf..a856a5b1a7 100644
--- a/src/lib/libcrypto/ec/ec2_oct.c
+++ b/src/lib/libcrypto/ec/ec2_oct.c
@@ -21,7 +21,7 @@
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer. 
+ *    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
@@ -74,11 +74,11 @@
 #ifndef OPENSSL_NO_EC2M
 
 /* Calculates and sets the affine coordinates of an EC_POINT from the given
- * compressed coordinates.  Uses algorithm 2.3.4 of SEC 1. 
+ * compressed coordinates.  Uses algorithm 2.3.4 of SEC 1.
  * Note that the simple implementation only uses affine coordinates.
  *
  * The method is from the following publication:
- * 
+ *
  *     Harper, Menezes, Vanstone:
  *     "Public-Key Cryptosystems with Very Small Key Lengths",
  *     EUROCRYPT '92, Springer-Verlag LNCS 658,
@@ -88,9 +88,10 @@
  * the same method, but claim no priority date earlier than July 29, 1994
  * (and additionally fail to cite the EUROCRYPT '92 publication as prior art).
  */
-int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
-        const BIGNUM *x_, int y_bit, BN_CTX *ctx)
-        {
+int 
+ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
+    const BIGNUM *x_, int y_bit, BN_CTX *ctx)
+{
         BN_CTX *new_ctx = NULL;
         BIGNUM *tmp, *x, *y, *z;
         int ret = 0, z0;
@@ -98,13 +99,11 @@ int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p
         /* clear error queue */
         ERR_clear_error();
 
-        if (ctx == NULL)
-                {
+        if (ctx == NULL) {
                 ctx = new_ctx = BN_CTX_new();
                 if (ctx == NULL)
                         return 0;
-                }
-
+        }
         y_bit = (y_bit != 0) ? 1 : 0;
 
         BN_CTX_start(ctx);
@@ -112,59 +111,65 @@ int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p
         x = BN_CTX_get(ctx);
         y = BN_CTX_get(ctx);
         z = BN_CTX_get(ctx);
-        if (z == NULL) goto err;
+        if (z == NULL)
+                goto err;
 
-        if (!BN_GF2m_mod_arr(x, x_, group->poly)) goto err;
-        if (BN_is_zero(x))
-                {
-                if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx)) goto err;
-                }
-        else
-                {
-                if (!group->meth->field_sqr(group, tmp, x, ctx)) goto err;
-                if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) goto err;
-                if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err;
-                if (!BN_GF2m_add(tmp, x, tmp)) goto err;
-                if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx))
-                        {
+        if (!BN_GF2m_mod_arr(x, x_, group->poly))
+                goto err;
+        if (BN_is_zero(x)) {
+                if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx))
+                        goto err;
+        } else {
+                if (!group->meth->field_sqr(group, tmp, x, ctx))
+                        goto err;
+                if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx))
+                        goto err;
+                if (!BN_GF2m_add(tmp, &group->a, tmp))
+                        goto err;
+                if (!BN_GF2m_add(tmp, x, tmp))
+                        goto err;
+                if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx)) {
                         unsigned long err = ERR_peek_last_error();
-                        
-                        if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NO_SOLUTION)
-                                {
+
+                        if (ERR_GET_LIB(err) == ERR_LIB_BN &&
+                            ERR_GET_REASON(err) == BN_R_NO_SOLUTION) {
                                 ERR_clear_error();
                                 ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
-                                }
-                        else
+                        } else
                                 ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
                         goto err;
-                        }
+                }
                 z0 = (BN_is_odd(z)) ? 1 : 0;
-                if (!group->meth->field_mul(group, y, x, z, ctx)) goto err;
-                if (z0 != y_bit)
-                        {
-                        if (!BN_GF2m_add(y, y, x)) goto err;
-                        }
+                if (!group->meth->field_mul(group, y, x, z, ctx))
+                        goto err;
+                if (z0 != y_bit) {
+                        if (!BN_GF2m_add(y, y, x))
+                                goto err;
                 }
+        }
 
-        if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
+        if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx))
+                goto err;
 
         ret = 1;
 
- err:
+err:
         BN_CTX_end(ctx);
         if (new_ctx != NULL)
                 BN_CTX_free(new_ctx);
         return ret;
-        }
+}
 
 
-/* Converts an EC_POINT to an octet string.  
+/* 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.
  */
-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 
+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;
@@ -172,131 +177,114 @@ size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, po
         size_t field_len, i, skip;
 
         if ((form != POINT_CONVERSION_COMPRESSED)
-                && (form != POINT_CONVERSION_UNCOMPRESSED)
-                && (form != POINT_CONVERSION_HYBRID))
-                {
+            && (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))
-                {
+        }
+        if (EC_POINT_is_at_infinity(group, point)) {
                 /* encodes to a single 0 octet */
-                if (buf != NULL)
-                        {
-                        if (len < 1)
-                                {
+                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;
+                        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;
+        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)
-                        {
+        if (buf != NULL) {
+                if (len < ret) {
                         ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
                         goto err;
-                        }
-
-                if (ctx == NULL)
-                        {
+                }
+                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 (yxi == NULL)
+                        goto err;
 
-                if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
+                if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx))
+                        goto err;
 
                 buf[0] = form;
-                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]++;
-                        }
-
+                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]++;
+                }
                 i = 1;
-                
+
                 skip = field_len - BN_num_bytes(x);
-                if (skip > field_len)
-                        {
+                if (skip > field_len) {
                         ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
                         goto err;
-                        }
-                while (skip > 0)
-                        {
+                }
+                while (skip > 0) {
                         buf[i++] = 0;
                         skip--;
-                        }
+                }
                 skip = BN_bn2bin(x, buf + i);
                 i += skip;
-                if (i != 1 + field_len)
-                        {
+                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)
-                        {
+                }
+                if (form == POINT_CONVERSION_UNCOMPRESSED ||
+                    form == POINT_CONVERSION_HYBRID) {
                         skip = field_len - BN_num_bytes(y);
-                        if (skip > field_len)
-                                {
+                        if (skip > field_len) {
                                 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
                                 goto err;
-                                }
-                        while (skip > 0)
-                                {
+                        }
+                        while (skip > 0) {
                                 buf[i++] = 0;
                                 skip--;
-                                }
+                        }
                         skip = BN_bn2bin(y, buf + i);
                         i += skip;
-                        }
-
-                if (i != ret)
-                        {
+                }
+                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:
+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. 
+/* 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)
-        {
+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;
@@ -304,104 +292,89 @@ int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
         size_t field_len, enc_len;
         int ret = 0;
 
-        if (len == 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 & ~1U;
-        if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
-                && (form != POINT_CONVERSION_UNCOMPRESSED)
-                && (form != POINT_CONVERSION_HYBRID))
-                {
+        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)
-                {
+        }
+        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)
-                        {
+        }
+        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);
                 }
-        
+                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;
+        enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len :
+            1 + 2 * field_len;
 
-        if (len != enc_len)
-                {
+        if (len != enc_len) {
                 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
                 return 0;
-                }
-
-        if (ctx == NULL)
-                {
+        }
+        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 (yxi == NULL)
+                goto err;
 
-        if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
-        if (BN_ucmp(x, &group->field) >= 0)
-                {
+        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)
-                        {
+        }
+        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))
-                                {
+                }
+                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 */
-                {
+                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:
+
+err:
         BN_CTX_end(ctx);
         if (new_ctx != NULL)
                 BN_CTX_free(new_ctx);
         return ret;
-        }
+}
 #endif