Add SNI support to redbean and improve SSL perf

This change makes SSL virtual hosting possible. You can now load
multiple certificates for multiple domains and redbean will just
figure out which one to use, even if you only have 1 ip address.
You can also use a jumbo certificate that lists all your domains
in the the subject alternative names.

This change also makes performance improvements to MbedTLS. Here
are some benchmarks vs. cc1920749e

                                   BEFORE    AFTER   (microsecs)
suite_ssl.com                     2512881   191738 13.11x faster
suite_pkparse.com                   36291     3295 11.01x faster
suite_x509parse.com                854669   120293  7.10x faster
suite_pkwrite.com                    6549     1265  5.18x faster
suite_ecdsa.com                     53347    18778  2.84x faster
suite_pk.com                        49051    18717  2.62x faster
suite_ecdh.com                      19535     9502  2.06x faster
suite_shax.com                      15848     7965  1.99x faster
suite_rsa.com                      353257   184828  1.91x faster
suite_x509write.com                162646    85733  1.90x faster
suite_ecp.com                       20503    11050  1.86x faster
suite_hmac_drbg.no_reseed.com       19528    11417  1.71x faster
suite_hmac_drbg.nopr.com            12460     8010  1.56x faster
suite_mpi.com                      687124   442661  1.55x faster
suite_hmac_drbg.pr.com              11890     7752  1.53x faster

There aren't any special tricks to the performance imporvements.
It's mostly due to code cleanup, assembly and intel instructions
like mulx, adox, and adcx.

third_party/mbedtls/test/lib.c

@@ -15,17 +15,21 @@
  *  limitations under the License.
  */
 #include "libc/assert.h"
+#include "libc/bits/bits.h"
 #include "libc/calls/calls.h"
 #include "libc/fmt/conv.h"
 #include "libc/fmt/fmt.h"
 #include "libc/log/log.h"
+#include "libc/mem/mem.h"
 #include "libc/rand/rand.h"
 #include "libc/runtime/internal.h"
+#include "libc/stdio/append.internal.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/exit.h"
 #include "third_party/mbedtls/config.h"
 #include "third_party/mbedtls/endian.h"
+#include "third_party/mbedtls/error.h"
 #include "third_party/mbedtls/platform.h"
 #include "third_party/mbedtls/test/lib.h"
 
@@ -49,14 +53,29 @@ typedef struct {
 static param_failed_ctx_t param_failed_ctx;
 #endif
 
+struct Buffer {
+  size_t i, n;
+  char *p;
+};
+
+char *output;
 jmp_buf jmp_tmp;
 int option_verbose;
-struct Buffer output;
 mbedtls_test_info_t mbedtls_test_info;
 
+static uint64_t Rando(void) {
+  static uint64_t x = 0x18abac12f3191aed;
+  uint64_t z = (x += 0x9e3779b97f4a7c15);
+  z = (z ^ (z >> 30)) * 0xbf58476d1ce4e5b9;
+  z = (z ^ (z >> 27)) * 0x94d049bb133111eb;
+  return z ^ (z >> 31);
+}
+
 int mbedtls_test_platform_setup(void) {
   int ret = 0;
   showcrashreports();
+  setvbuf(stdout, malloc(BUFSIZ), _IOLBF, BUFSIZ);
+  setvbuf(stderr, malloc(BUFSIZ), _IOLBF, BUFSIZ);
 #if defined(MBEDTLS_PLATFORM_C)
   ret = mbedtls_platform_setup(&platform_ctx);
 #endif /* MBEDTLS_PLATFORM_C */
@@ -70,36 +89,45 @@ void mbedtls_test_platform_teardown(void) {
 }
 
 wontreturn void exit(int rc) {
-  if (rc != EXIT_SUCCESS) {
-    fwrite(output.p, 1, output.i, stderr);
-  }
+  if (rc) fwrite(output, 1, appendz(output).i, stderr);
   __cxa_finalize(0);
   _Exit(rc);
 }
 
-int AppendFmt(struct Buffer *b, const char *fmt, ...) {
+char *GetTlsError(long r) {
+  char s[128];
+  if (-0x10000 < r && r < 0) {
+    mbedtls_strerror(r, s, sizeof(s));
+    return xasprintf("-0x%04lx %s", -r, s);
+  } else {
+    return xasprintf("%#lx", r);
+  }
+}
+
+int mbedtls_hardware_poll(void *wut, unsigned char *p, size_t n, size_t *olen) {
+  uint64_t x;
+  size_t i, j;
+  unsigned char b[8];
+  for (i = 0; i < n; ++i) {
+    x = Rando();
+    WRITE64LE(b, x);
+    for (j = 0; j < 8 && i + j < n; ++j) {
+      p[i + j] = b[j];
+    }
+  }
+  *olen = n;
+  return 0;
+}
+
+int mbedtls_test_write(const char *fmt, ...) {
   char *p;
   int i, n;
-  va_list va, vb;
+  va_list va;
   va_start(va, fmt);
   if (option_verbose) {
     n = vfprintf(stderr, fmt, va);
   } else {
-    va_copy(vb, va);
-    n = vsnprintf(b->p + b->i, b->n - b->i, fmt, va);
-    if (n >= b->n - b->i) {
-      do {
-        if (b->n) {
-          b->n += b->n >> 1;
-        } else {
-          b->n = 16;
-        }
-      } while (b->i + n > b->n);
-      b->p = realloc(b->p, b->n);
-      vsnprintf(b->p + b->i, b->n - b->i, fmt, vb);
-    }
-    va_end(vb);
-    b->i += n;
+    n = vappendf(&output, fmt, va);
   }
   va_end(va);
   return n;
@@ -264,14 +292,16 @@ void mbedtls_test_hexify(unsigned char *obuf, const unsigned char *ibuf,
   while (len != 0) {
     h = *ibuf / 16;
     l = *ibuf % 16;
-    if (h < 10)
+    if (h < 10) {
       *obuf++ = '0' + h;
-    else
+    } else {
       *obuf++ = 'a' + h - 10;
-    if (l < 10)
+    }
+    if (l < 10) {
       *obuf++ = '0' + l;
-    else
+    } else {
       *obuf++ = 'a' + l - 10;
+    }
     ++ibuf;
     len--;
   }
@@ -1037,7 +1067,7 @@ int execute_tests(int argc, const char **argv, const char *default_filename) {
         if (mbedtls_test_info.result == MBEDTLS_TEST_RESULT_SUCCESS) {
           WRITE("PASS (%,ldus)\n", (int64_t)((t2 - t1) * 1e6));
         } else if (mbedtls_test_info.result == MBEDTLS_TEST_RESULT_SKIPPED) {
-          WRITE("----\n");
+          WRITE("----");
           total_skipped++;
         } else {
           total_errors++;