knf approximation

1 files changed, 169 insertions, 204 deletions

diff --git a/lib/libcrypto/ec/ecp_oct.c b/lib/libcrypto/ec/ecp_oct.c
index a06abbc8cd6..c7719c74132 100644
--- a/lib/libcrypto/ec/ecp_oct.c
+++ b/lib/libcrypto/ec/ecp_oct.c
@@ -1,6 +1,6 @@
 /* crypto/ec/ecp_oct.c */
 /* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
- * for the OpenSSL project. 
+ * for the OpenSSL project.
  * Includes code written by Bodo Moeller for the OpenSSL project.
 */
 /* ====================================================================
@@ -11,7 +11,7 @@
  * 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
@@ -66,23 +66,22 @@
 
 #include "ec_lcl.h"
 
-int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
-	const BIGNUM *x_, int y_bit, BN_CTX *ctx)
-	{
+int 
+ec_GFp_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 *tmp1, *tmp2, *x, *y;
 	int ret = 0;
 
-	/* clear error queue*/
+	/* 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);
 
 	BN_CTX_start(ctx);
@@ -90,114 +89,117 @@ int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *po
 	tmp2 = BN_CTX_get(ctx);
 	x = BN_CTX_get(ctx);
 	y = BN_CTX_get(ctx);
-	if (y == NULL) goto err;
+	if (y == NULL)
+		goto err;
 
-	/* Recover y.  We have a Weierstrass equation
-	 *     y^2 = x^3 + a*x + b,
-	 * so  y  is one of the square roots of  x^3 + a*x + b.
+	/*
+	 * Recover y.  We have a Weierstrass equation y^2 = x^3 + a*x + b, so
+	 * y  is one of the square roots of  x^3 + a*x + b.
 	 */
 
 	/* tmp1 := x^3 */
-	if (!BN_nnmod(x, x_, &group->field,ctx)) goto err;
-	if (group->meth->field_decode == 0)
-		{
+	if (!BN_nnmod(x, x_, &group->field, ctx))
+		goto err;
+	if (group->meth->field_decode == 0) {
 		/* field_{sqr,mul} work on standard representation */
-		if (!group->meth->field_sqr(group, tmp2, x_, ctx)) goto err;
-		if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx)) goto err;
-		}
-	else
-		{
-		if (!BN_mod_sqr(tmp2, x_, &group->field, ctx)) goto err;
-		if (!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx)) goto err;
-		}
-	
+		if (!group->meth->field_sqr(group, tmp2, x_, ctx))
+			goto err;
+		if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx))
+			goto err;
+	} else {
+		if (!BN_mod_sqr(tmp2, x_, &group->field, ctx))
+			goto err;
+		if (!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx))
+			goto err;
+	}
+
 	/* tmp1 := tmp1 + a*x */
-	if (group->a_is_minus3)
-		{
-		if (!BN_mod_lshift1_quick(tmp2, x, &group->field)) goto err;
-		if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field)) goto err;
-		if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
-		}
-	else
-		{
-		if (group->meth->field_decode)
-			{
-			if (!group->meth->field_decode(group, tmp2, &group->a, ctx)) goto err;
-			if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) goto err;
-			}
-		else
-			{
+	if (group->a_is_minus3) {
+		if (!BN_mod_lshift1_quick(tmp2, x, &group->field))
+			goto err;
+		if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field))
+			goto err;
+		if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field))
+			goto err;
+	} else {
+		if (group->meth->field_decode) {
+			if (!group->meth->field_decode(group, tmp2, &group->a, ctx))
+				goto err;
+			if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx))
+				goto err;
+		} else {
 			/* field_mul works on standard representation */
-			if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx)) goto err;
-			}
-		
-		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
+			if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx))
+				goto err;
 		}
-	
+
+		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field))
+			goto err;
+	}
+
 	/* tmp1 := tmp1 + b */
-	if (group->meth->field_decode)
-		{
-		if (!group->meth->field_decode(group, tmp2, &group->b, ctx)) goto err;
-		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
-		}
-	else
-		{
-		if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) goto err;
-		}
-	
-	if (!BN_mod_sqrt(y, tmp1, &group->field, ctx))
-		{
+	if (group->meth->field_decode) {
+		if (!group->meth->field_decode(group, tmp2, &group->b, ctx))
+			goto err;
+		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field))
+			goto err;
+	} else {
+		if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field))
+			goto err;
+	}
+
+	if (!BN_mod_sqrt(y, tmp1, &group->field, ctx)) {
 		unsigned long err = ERR_peek_last_error();
-		
-		if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE)
-			{
+
+		if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE) {
 			ERR_clear_error();
 			ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
-			}
-		else
+		} else
 			ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
 		goto err;
-		}
-
-	if (y_bit != BN_is_odd(y))
-		{
-		if (BN_is_zero(y))
-			{
+	}
+	if (y_bit != BN_is_odd(y)) {
+		if (BN_is_zero(y)) {
 			int kron;
 
 			kron = BN_kronecker(x, &group->field, ctx);
-			if (kron == -2) goto err;
+			if (kron == -2)
+				goto err;
 
 			if (kron == 1)
 				ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSION_BIT);
 			else
-				/* BN_mod_sqrt() should have cought this error (not a square) */
+				/*
+				 * BN_mod_sqrt() should have cought this
+				 * error (not a square)
+				 */
 				ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
 			goto err;
-			}
-		if (!BN_usub(y, &group->field, y)) goto err;
 		}
-	if (y_bit != BN_is_odd(y))
-		{
+		if (!BN_usub(y, &group->field, y))
+			goto err;
+	}
+	if (y_bit != BN_is_odd(y)) {
 		ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_INTERNAL_ERROR);
 		goto err;
-		}
-
-	if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+	}
+	if (!EC_POINT_set_affine_coordinates_GFp(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;
-	}
+}
 
 
-size_t ec_GFp_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_GFp_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;
@@ -205,125 +207,106 @@ size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, poi
 	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_GFP_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_GFP_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 = BN_num_bytes(&group->field);
-	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_GFP_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);
-		if (y == NULL) goto err;
+		if (y == NULL)
+			goto err;
 
-		if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+		if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx))
+			goto err;
 
 		if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
 			buf[0] = form + 1;
 		else
 			buf[0] = form;
-	
+
 		i = 1;
-		
+
 		skip = field_len - BN_num_bytes(x);
-		if (skip > field_len)
-			{
+		if (skip > field_len) {
 			ECerr(EC_F_EC_GFP_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_GFP_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_GFP_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_GFP_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;
-	}
+}
 
 
-int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
-	const unsigned char *buf, size_t len, BN_CTX *ctx)
-	{
+int 
+ec_GFp_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;
@@ -331,102 +314,84 @@ int ec_GFp_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_GFP_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_GFP_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_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
 		return 0;
-		}
-
-	if (form == 0)
-		{
-		if (len != 1)
-			{
+	}
+	if (form == 0) {
+		if (len != 1) {
 			ECerr(EC_F_EC_GFP_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 = BN_num_bytes(&group->field);
-	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_GFP_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);
-	if (y == NULL) goto err;
+	if (y == 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_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
 		goto err;
-		}
-
-	if (form == POINT_CONVERSION_COMPRESSED)
-		{
-		if (!EC_POINT_set_compressed_coordinates_GFp(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_GFp(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_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
 			goto err;
-			}
-		if (form == POINT_CONVERSION_HYBRID)
-			{
-			if (y_bit != BN_is_odd(y))
-				{
+		}
+		if (form == POINT_CONVERSION_HYBRID) {
+			if (y_bit != BN_is_odd(y)) {
 				ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
 				goto err;
-				}
 			}
-
-		if (!EC_POINT_set_affine_coordinates_GFp(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_GFp(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_GFP_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;
-	}
-
+}