mbedTLS: Update to new LTS v3.6.0

Keep module compatibility with mbedtls 2.x (old LTS branch).

A patch has been added to allow compiling after removing all the `psa_*`
files from the library folder (will look into upstreaming it).

Note: mbedTLS 3.6 finally enabled TLSv1.3 by default, but it requires
some module changes, and to enable PSA crypto (new "standard" API
specification), so it might be best done in a separate commit/PR.

1 files changed, 39 insertions, 5 deletions

diff --git a/thirdparty/mbedtls/library/base64.c b/thirdparty/mbedtls/library/base64.c
index 1f1a90a937..9677dee5b2 100644
--- a/thirdparty/mbedtls/library/base64.c
+++ b/thirdparty/mbedtls/library/base64.c
@@ -5,11 +5,14 @@
  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  */
 
+#include <limits.h>
+
 #include "common.h"
 
 #if defined(MBEDTLS_BASE64_C)
 
 #include "mbedtls/base64.h"
+#include "base64_internal.h"
 #include "constant_time_internal.h"
 
 #include <stdint.h>
@@ -19,7 +22,38 @@
 #include "mbedtls/platform.h"
 #endif /* MBEDTLS_SELF_TEST */
 
-#define BASE64_SIZE_T_MAX   ((size_t) -1)   /* SIZE_T_MAX is not standard */
+MBEDTLS_STATIC_TESTABLE
+unsigned char mbedtls_ct_base64_enc_char(unsigned char value)
+{
+    unsigned char digit = 0;
+    /* For each range of values, if value is in that range, mask digit with
+     * the corresponding value. Since value can only be in a single range,
+     * only at most one masking will change digit. */
+    digit |= mbedtls_ct_uchar_in_range_if(0, 25, value, 'A' + value);
+    digit |= mbedtls_ct_uchar_in_range_if(26, 51, value, 'a' + value - 26);
+    digit |= mbedtls_ct_uchar_in_range_if(52, 61, value, '0' + value - 52);
+    digit |= mbedtls_ct_uchar_in_range_if(62, 62, value, '+');
+    digit |= mbedtls_ct_uchar_in_range_if(63, 63, value, '/');
+    return digit;
+}
+
+MBEDTLS_STATIC_TESTABLE
+signed char mbedtls_ct_base64_dec_value(unsigned char c)
+{
+    unsigned char val = 0;
+    /* For each range of digits, if c is in that range, mask val with
+     * the corresponding value. Since c can only be in a single range,
+     * only at most one masking will change val. Set val to one plus
+     * the desired value so that it stays 0 if c is in none of the ranges. */
+    val |= mbedtls_ct_uchar_in_range_if('A', 'Z', c, c - 'A' +  0 + 1);
+    val |= mbedtls_ct_uchar_in_range_if('a', 'z', c, c - 'a' + 26 + 1);
+    val |= mbedtls_ct_uchar_in_range_if('0', '9', c, c - '0' + 52 + 1);
+    val |= mbedtls_ct_uchar_in_range_if('+', '+', c, c - '+' + 62 + 1);
+    val |= mbedtls_ct_uchar_in_range_if('/', '/', c, c - '/' + 63 + 1);
+    /* At this point, val is 0 if c is an invalid digit and v+1 if c is
+     * a digit with the value v. */
+    return val - 1;
+}
 
 /*
  * Encode a buffer into base64 format
@@ -38,8 +72,8 @@ int mbedtls_base64_encode(unsigned char *dst, size_t dlen, size_t *olen,
 
     n = slen / 3 + (slen % 3 != 0);
 
-    if (n > (BASE64_SIZE_T_MAX - 1) / 4) {
-        *olen = BASE64_SIZE_T_MAX;
+    if (n > (SIZE_MAX - 1) / 4) {
+        *olen = SIZE_MAX;
         return MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL;
     }
 
@@ -82,7 +116,7 @@ int mbedtls_base64_encode(unsigned char *dst, size_t dlen, size_t *olen,
         *p++ = '=';
     }
 
-    *olen = p - dst;
+    *olen = (size_t) (p - dst);
     *p = 0;
 
     return 0;
@@ -191,7 +225,7 @@ int mbedtls_base64_decode(unsigned char *dst, size_t dlen, size_t *olen,
         }
     }
 
-    *olen = p - dst;
+    *olen = (size_t) (p - dst);
 
     return 0;
 }