Allow null buffers when the length is 0

Signed-off-by: Gilles Peskine <[email protected]>
Mbed-TLS · Feb 26, 2024 · 9721b86 · 9721b86
1 parent 84dc44b
commit 9721b86
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/library/ecp.c b/library/ecp.c
@@ -927,7 +927,7 @@ int mbedtls_ecp_point_read_binary(const mbedtls_ecp_group *grp,
     size_t plen;
     ECP_VALIDATE_RET(grp != NULL);
     ECP_VALIDATE_RET(pt  != NULL);
-    ECP_VALIDATE_RET(buf != NULL);
+    ECP_VALIDATE_RET(ilen == 0 || buf != NULL);
 
     if (ilen < 1) {
         return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
@@ -996,7 +996,7 @@ int mbedtls_ecp_tls_read_point(const mbedtls_ecp_group *grp,
     ECP_VALIDATE_RET(grp != NULL);
     ECP_VALIDATE_RET(pt  != NULL);
     ECP_VALIDATE_RET(buf != NULL);
-    ECP_VALIDATE_RET(*buf != NULL);
+    ECP_VALIDATE_RET(buf_len == 0 || *buf != NULL);
 
     /*
      * We must have at least two bytes (1 for length, at least one for data)
@@ -1068,7 +1068,7 @@ int mbedtls_ecp_tls_read_group(mbedtls_ecp_group *grp,
     mbedtls_ecp_group_id grp_id;
     ECP_VALIDATE_RET(grp  != NULL);
     ECP_VALIDATE_RET(buf  != NULL);
-    ECP_VALIDATE_RET(*buf != NULL);
+    ECP_VALIDATE_RET(len == 0 || *buf != NULL);
 
     if ((ret = mbedtls_ecp_tls_read_group_id(&grp_id, buf, len)) != 0) {
         return ret;
@@ -1088,7 +1088,7 @@ int mbedtls_ecp_tls_read_group_id(mbedtls_ecp_group_id *grp,
     const mbedtls_ecp_curve_info *curve_info;
     ECP_VALIDATE_RET(grp  != NULL);
     ECP_VALIDATE_RET(buf  != NULL);
-    ECP_VALIDATE_RET(*buf != NULL);
+    ECP_VALIDATE_RET(len == 0 || *buf != NULL);
 
     /*
      * We expect at least three bytes (see below)
@@ -3361,7 +3361,7 @@ int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key,
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     ECP_VALIDATE_RET(key != NULL);
-    ECP_VALIDATE_RET(buf != NULL);
+    ECP_VALIDATE_RET(buflen == 0 || buf != NULL);
 
 #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED)
     if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) {