Merge pull request #210 from gojimmypi/pr-realm-update

Update realm patch and build script with latest wolfssl support

.gitignore

@@ -110,3 +110,4 @@ openssh/regress/authorized_keys*
 stunnel/example/echoserver/echoserver*
 *.plist
 server_err.log
+/.vs

realm/README.md

@@ -1,3 +1,53 @@
+# REALM with wolfSSL
+
+The wolfSSL library is enabled in [realm-core](https://github.com/realm/realm-core) with the `-DREALM_HAVE_WOLFSSL=1` parameter.
+
+The upstream `realm-core` does NOT yet support wolfSSL. Please see the enclosed `realm-commit-[hash].patch files`.
+
+The Linux Script Build automatically applies these patches as needed. Modify as desired with the `REALM_CORE_COMMIT` script variable.
+
+## Linux Script Build
+
+The [build_wolfssl_with_realm.sh](./build_wolfssl_with_realm.sh) script can be used.
+
+### Script Parameters:
+
+* `-t` use tarball, not git
+* `-u` use $USER name suffix for repository
+
+###
+
+Defaults are to clone [wolfSSL](https://github.com/wolfSSL/wolfssl) and [realm-core](https://github.com/realm/realm-core) to local directory.
+
+If you have forks of each with your GitHub ID the same as your local user name, the `-u` is recommended.
+
+Run directly from the `realm` directory:
+
+```bash
+./build_wolfssl_with_realm.sh -u
+```
+
+This will create these local directories, and add respective `upstream` repository settings:
+
+```text
+./wolfssl-<your username>
+./realm-core-<your username>
+```
+
+Once the desired wolfSSL library has been fetched and installed, the clone / config / build can be skipped by making these changes in the script file:
+
+```
+# Choose to skip parts of wolfSSL build:
+FETCH_WOLFSSL=false
+CONFIGURE_WOLFSSL=false
+BUILD_WOLFSSL=false
+INSTALL_WOLFSSL=false
+```
+
+## Linux manual build: Build wolfSSL
+
+These commands are wrapped in the `build_wolfssl_with_realm.sh` script, mentioned above:
+
 To configure wolfSSL, use the following command:
 
 ```
@@ -22,10 +72,60 @@ Building realm-core:
 
 ```
 mkdir build
-cmake -B build -DREALM_ENABLE_ENCRYPTION=1 -DREALM_ENABLE_SYNC=1 -DREALM_USE_WOLFSSL=1 -DREALM_WOLFSSL_ROOT_DIR=/usr/local/lib
+cmake -B build -DREALM_ENABLE_ENCRYPTION=1 -DREALM_ENABLE_SYNC=1 -DREALM_HAVE_WOLFSSL=1 -DREALM_WOLFSSL_ROOT_DIR=/usr/local/lib
 cmake --build build
 ./build/test/realm-tests
 ```
 
 You can also use the build_wolfssl_with_realm.sh script after adjusting the global variables as needed.
 
+## Generating a new Realm-core patch file:
+
+To generate a new patch compare a particular commit (a5e87a39) to your fork/branch (`dev`):
+
+Save the generated file from this link to the `realm-commit-a5e87a39.patch` file:
+
+
+
+```
+https://github.com/gojimmypi/realm-core/compare/a5e87a39...dev.patch
+
+or
+
+https://github.com/gojimmypi/realm-core/compare/a5e87a39...gojimmypi:realm-core:dev-consolidated.patch
+```
+
+Do *not* edit the patch file for tailing spaces, etc. It must be saved exactly as generated.
+
+## Troubleshooting
+
+### Confirming build with wolfSSL
+
+See generated `config.h` files:
+
+For Linux compile: `build` directory:
+```
+[wolfssl osp root]\realm\realm-core\build\src\realm\util
+```
+
+For Visual Studio compile: `out` directory, plus build configuration (e.g. `build\x64-Debug`):
+
+```
+[wolfssl osp root]\realm\realm-core\out\build\x64-Debug\src\realm\util
+```
+
+### Cannot find OpenSSL
+
+```
+Cannot open include file: 'openssl/sha.h': No such file or directory	Storage	C:\workspace\osp-gojimmypi\realm\realm-core-gojimmypi\src\realm\util\aes_cryptor.hpp
+```
+
+Check the `osp\realm\VS2022\src\realm\util` directory. The generated `config.h` should have
+openSSL disabled `0` and wolfSSL enabled `1` like this:
+
+```
+#define REALM_HAVE_OPENSSL 0
+#define REALM_HAVE_WOLFSSL 1
+```
+
+###