fix new line difference in Windows

Signed-off-by: Valerio Setti <[email protected]>

tests/suites/test_suite_pkwrite.function

@@ -8,6 +8,25 @@ typedef enum {
     TEST_DER
 } pkwrite_file_format_t;
 
+/* Helper function for removing "\r" chars from a buffer. This i */
+static void fix_new_lines(unsigned char *in_str, size_t *len)
+{
+    size_t chars_left;
+    unsigned int i;
+
+    for (i = 0; (i < *len) && (*len > 0); i++) {
+        if (in_str[i] == '\r') {
+            if (i < (*len - 1)) {
+                chars_left = *len - i - 1;
+                memcpy(&in_str[i], &in_str[i+1], chars_left);
+            } else {
+                in_str[i] = '\0';
+            }
+            *len = *len - 1;
+        }
+    }
+}
+
 static void pk_write_check_common(char *key_file, int is_public_key, int is_der)
 {
     mbedtls_pk_context key;
@@ -22,6 +41,19 @@ static void pk_write_check_common(char *key_file, int is_public_key, int is_der)
     TEST_EQUAL(mbedtls_pk_load_file(key_file, &check_buf, &check_buf_len), 0);
     TEST_ASSERT(check_buf_len > 0);
 
+    /* Windows' line ending is different from the Linux's one ("\r\n" vs "\n").
+     * Git treats PEM files as text, so when on Windows, it replaces new lines
+     * with "\r\n" on checkout.
+     * Unfortunately mbedtls_pk_load_file() loads files in binary format,
+     * while mbedtls_pk_write_pubkey_pem() goes through the I/O layer which
+     * uses "\n" for newlines in both Windows and Linux.
+     * Here we remove the extra "\r" so that "buf" and "check_buf" can be
+     * easily compared later. */
+    if (!is_der) {
+        fix_new_lines(check_buf, &check_buf_len);
+    }
+    TEST_ASSERT(check_buf_len > 0);
+
     ASSERT_ALLOC(buf, check_buf_len);
 
     mbedtls_pk_init(&key);