Add EC_POINT_hex2point: zd #17090

wolfSSL · May 29, 2024 · 7839f39 · 7839f39
1 parent 791c9e7
commit 7839f39
Showing 1 changed file with 15 additions and 24 deletions.
diff --git a/src/pk.c b/src/pk.c
@@ -32,6 +32,12 @@
 
 #ifdef HAVE_ECC
     #include <wolfssl/wolfcrypt/ecc.h>
+    #ifdef HAVE_SELFTEST
+        /* point compression types. */
+        #define ECC_POINT_COMP_EVEN 0x02
+        #define ECC_POINT_COMP_ODD  0x03
+        #define ECC_POINT_UNCOMP    0x04
+    #endif
 #endif
 #ifndef WOLFSSL_HAVE_ECC_KEY_GET_PRIV
     /* FIPS build has replaced ecc.h. */
@@ -9787,12 +9793,12 @@ char* wolfSSL_EC_POINT_point2hex(const WOLFSSL_EC_GROUP* group,
              * odd.
              */
             hex[0] = mp_isodd((mp_int*)point->Y->internal) ?
-                0x03 : 0x02;
+                ECC_POINT_COMP_ODD : ECC_POINT_COMP_EVEN;
             /* No y-ordinate. */
         }
         else {
             /* Put in uncompressed format byte. */
-            hex[0] = 0x04;
+            hex[0] = ECC_POINT_UNCOMP;
             /* Calculate offset as leading zeros not encoded. */
             i = 1 + 2 * sz - mp_unsigned_bin_size((mp_int*)point->Y->internal);
             /* Put in y-ordinate after x-ordinate. */
@@ -9848,13 +9854,12 @@ WOLFSSL_EC_POINT*wolfSSL_EC_POINT_hex2point(const EC_GROUP *group,
     size_t str_sz;
     BIGNUM *Gx  = NULL;
     BIGNUM *Gy  = NULL;
-    char   *strGx = NULL;
+    char   strGx[MAX_ECC_BYTES * 2];
 
-     /* for compressed mode */
+    /* for compressed mode */
     int    key_sz;
-    byte   *octGx = NULL;
+    byte   *octGx = (byte *)strGx; /* octGx[MAX_ECC_BYTES] */
 
-    #define P_ALLOC 1
     int p_alloc = 0;
     int ret;
 
@@ -9868,16 +9873,12 @@ WOLFSSL_EC_POINT*wolfSSL_EC_POINT_hex2point(const EC_GROUP *group,
             WOLFSSL_MSG("wolfSSL_EC_POINT_new");
             goto err;
         }
-        p_alloc = P_ALLOC;
+        p_alloc = 1;
     }
 
+    key_sz = (wolfSSL_EC_GROUP_get_degree(group) + 7) / 8;
     if (hex[0] ==  '0' && hex[1] == '4') { /* uncompressed mode */
-        str_sz = ((wolfSSL_EC_GROUP_get_degree(group) + 7) / 8) * 2;
-        strGx = (char *)XMALLOC(str_sz + 1, NULL, DYNAMIC_TYPE_ECC);
-        if (strGx == NULL) {
-            WOLFSSL_MSG("malloc error");
-            goto err;
-        }
+        str_sz = key_sz * 2;
 
         XMEMSET(strGx, 0x0, str_sz + 1);
         XMEMCPY(strGx, hex + 2, str_sz);
@@ -9898,13 +9899,7 @@ WOLFSSL_EC_POINT*wolfSSL_EC_POINT_hex2point(const EC_GROUP *group,
     }
     else if (hex[0] == '0' && (hex[1] == '2' || hex[1] == '3')) {
         /* compressed mode */
-        key_sz = ((wolfSSL_EC_GROUP_get_degree(group) + 7) / 8);
-        octGx = (byte *)XMALLOC(key_sz + 1, NULL, DYNAMIC_TYPE_ECC);
-        if (octGx == NULL) {
-            WOLFSSL_MSG("EEC_KEY_get_byte_size, XMALLOC");
-            goto err;
-        }
-        octGx[0] = 0x03;
+        octGx[0] = ECC_POINT_COMP_ODD;
         if (hex_to_bytes(hex + 2, octGx + 1, XSTRLEN(hex + 2) / 2)
                                             != XSTRLEN(hex + 2) / 2) {
             goto err;
@@ -9917,15 +9912,11 @@ WOLFSSL_EC_POINT*wolfSSL_EC_POINT_hex2point(const EC_GROUP *group,
     else
         goto err;
 
-    XFREE(strGx, NULL, DYNAMIC_TYPE_ECC);
-    XFREE(octGx, NULL, DYNAMIC_TYPE_ECC);
     wolfSSL_BN_free(Gx);
     wolfSSL_BN_free(Gy);
     return p;
 
 err:
-    XFREE(strGx, NULL, DYNAMIC_TYPE_ECC);
-    XFREE(octGx, NULL, DYNAMIC_TYPE_ECC);
     wolfSSL_BN_free(Gx);
     wolfSSL_BN_free(Gy);
     if (p_alloc) {