1 files changed, 337 insertions, 14 deletions

diff --git a/src/lib/libcrypto/ec/ec2_smpl.c b/src/lib/libcrypto/ec/ec2_smpl.c
index e0e59c7d82..03deae6674 100644
--- a/src/lib/libcrypto/ec/ec2_smpl.c
+++ b/src/lib/libcrypto/ec/ec2_smpl.c
@@ -71,20 +71,10 @@
 
 #include "ec_lcl.h"
 
-#ifndef OPENSSL_NO_EC2M
-
-#ifdef OPENSSL_FIPS
-#include <openssl/fips.h>
-#endif
-
 
 const EC_METHOD *EC_GF2m_simple_method(void)
         {
-#ifdef OPENSSL_FIPS
-        return fips_ec_gf2m_simple_method();
-#else
         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,
@@ -103,7 +93,9 @@ 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,
-                0,0,0,
+                ec_GF2m_simple_set_compressed_coordinates,
+                ec_GF2m_simple_point2oct,
+                ec_GF2m_simple_oct2point,
                 ec_GF2m_simple_add,
                 ec_GF2m_simple_dbl,
                 ec_GF2m_simple_invert,
@@ -126,7 +118,6 @@ const EC_METHOD *EC_GF2m_simple_method(void)
                 0 /* field_set_to_one */ };
 
         return &ret;
-#endif
         }
 
 
@@ -414,6 +405,340 @@ int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group, const EC_
         return ret;
         }
 
+
+/* Calculates and sets the affine coordinates of an EC_POINT from the given
+ * 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,
+ *     published February 1993
+ *
+ * US Patents 6,141,420 and 6,618,483 (Vanstone, Mullin, Agnew) describe
+ * 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)
+        {
+        BN_CTX *new_ctx = NULL;
+        BIGNUM *tmp, *x, *y, *z;
+        int ret = 0, z0;
+
+        /* clear error queue */
+        ERR_clear_error();
+
+        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);
+        tmp = BN_CTX_get(ctx);
+        x = BN_CTX_get(ctx);
+        y = BN_CTX_get(ctx);
+        z = BN_CTX_get(ctx);
+        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))
+                        {
+                        unsigned long err = ERR_peek_last_error();
+                        
+                        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
+                                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 (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
+
+        ret = 1;
+
+ err:
+        BN_CTX_end(ctx);
+        if (new_ctx != NULL)
+                BN_CTX_free(new_ctx);
+        return ret;
+        }
+
+
+/* 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 ret;
+        BN_CTX *new_ctx = NULL;
+        int used_ctx = 0;
+        BIGNUM *x, *y, *yxi;
+        size_t field_len, i, skip;
+
+        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;
+                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)
+                        {
+                        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 & ~1U;
+        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.
  */
@@ -715,5 +1040,3 @@ 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