Upgrade OpenSSL so it works on visionOS (#635)

* Switch OpenSSL so it works on visionOS
* Fix cert generation to work with OpenSSL 3
* Update gitignore

Limelight/Crypto/mkcert.c

@@ -4,10 +4,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <openssl/evp.h>
 #include <openssl/pem.h>
-#include <openssl/rsa.h>
+#include <OpenSSL/provider.h>
+#include <OpenSSL/rsa.h>
 #include <openssl/x509.h>
-#include <openssl/rand.h>
+#include <OpenSSL/rand.h>
 
 static const int NUM_BITS = 2048;
 static const int SERIAL = 0;
@@ -65,12 +67,34 @@ struct CertKeyPair generateCertKeyPair(void) {
     X509 *x509 = NULL;
     EVP_PKEY *pkey = NULL;
     PKCS12 *p12 = NULL;
+    // OpenSSL3 has default algorithms that iOS refuses to load so we
+    // must load the legacy provider and override all the algorithms
+    // in this cert.
+
+    OSSL_PROVIDER *_legacy = OSSL_PROVIDER_try_load(NULL, "legacy", 1);
+
+    if (_legacy == NULL) {
+        printf("Failed to load Legacy provider\n");
+    }
    
     bio_err = BIO_new_fp(stderr, BIO_NOCLOSE);
     
     mkcert(&x509, &pkey, NUM_BITS, SERIAL, NUM_YEARS);
-
-    p12 = PKCS12_create("limelight", "GameStream", pkey, x509, NULL, 0, 0, 0, 0, 0);
+    
+    char* pass = "limelight";
+    p12 = PKCS12_create(pass,
+                        "GameStream",
+                        pkey,
+                        x509,
+                        NULL,
+                        NID_pbe_WithSHA1And3_Key_TripleDES_CBC,
+                        NID_pbe_WithSHA1And40BitRC2_CBC,
+                        2048,
+                        -1, // disable the automatic MAC
+                        0);
+    // MAC it ourselves with SHA1 since iOS refuses to load anything else.
+    PKCS12_set_mac(p12, pass, -1, NULL, 0, 1, EVP_sha1());
+    
     if (p12 == NULL) {
         printf("Error generating a valid PKCS12 certificate.\n");
     }