Add a generateKeys JNI function

It goes via Dart -> Java -> JNI -> OurLib -> LibSSH. Also, it still
doesn't seem to work, and I'm not sure why. I kinda giveup for now.

android/app/src/main/cpp/CMakeLists.txt

@@ -21,7 +21,6 @@ set_target_properties(openssl-lib
         PROPERTIES IMPORTED_LOCATION
         ${lib_src_DIR}/lib/libssl.a)
 
-
 add_library(crypto-lib
         STATIC
         IMPORTED)
@@ -30,6 +29,13 @@ set_target_properties(crypto-lib
         PROPERTIES IMPORTED_LOCATION
         ${lib_src_DIR}/lib/libcrypto.a)
 
+add_library(ssh-lib
+        STATIC
+        IMPORTED)
+
+set_target_properties(ssh-lib
+        PROPERTIES IMPORTED_LOCATION
+        ${lib_src_DIR}/lib/libssh.a)
 
 add_library(ssh2-lib
         STATIC
@@ -39,7 +45,6 @@ set_target_properties(ssh2-lib
         PROPERTIES IMPORTED_LOCATION
         ${lib_src_DIR}/lib/libssh2.a)
 
-
 add_library(git2-lib
         STATIC
         IMPORTED)
@@ -50,8 +55,9 @@ set_target_properties(git2-lib
 
 add_library(native-lib
         SHARED
-        native-lib.cpp)
+        keygen.c
+)
 
 # The order of these libraries is super dooper important
 # Otherwise you'll get linker errors
-target_link_libraries(native-lib git2-lib ssh2-lib openssl-lib crypto-lib)
+target_link_libraries(native-lib git2-lib ssh2-lib ssh-lib openssl-lib crypto-lib android log)

android/app/src/main/cpp/keygen.c

@@ -0,0 +1,121 @@
+#include <jni.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+#include <libssh/libssh.h>
+#include <android/log.h>
+#include <errno.h>
+
+void change_pubickey_comment(const char *filename, const char *comment)
+{
+    FILE *fp = fopen(filename, "r");
+    char buff[10000];
+    fgets(buff, 10000, fp);
+    fclose(fp);
+
+    // Remove the comment
+    char *end = strchr(strchr(buff, ' ') + 1, ' ');
+    int len = end - buff + 1;
+    buff[len] = 0;
+
+    // Add custom comment
+    strcat(buff, comment);
+    strcat(buff, "\n");
+
+    // Write the file back
+    fp = fopen(filename, "w");
+    fputs(buff, fp);
+    fclose(fp);
+}
+
+int generate_keys(const char* private_key_path,
+                  const char* public_key_path,
+                  const char* comment)
+{
+    ssh_key key;
+
+    int ret = ssh_pki_generate(SSH_KEYTYPE_RSA, 4096, &key);
+    if (ret != SSH_OK)
+    {
+        return ret;
+    }
+
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", "KEY GENERATED");
+
+    /*
+    FILE*  file = fopen(private_key_path, "wb");
+        if (file == NULL) {
+                __android_log_print(ANDROID_LOG_ERROR, "HOWDY", "file is null %d", errno);
+                return 1;
+        }
+
+    struct stat sb;
+
+       int rc = fstat(fileno(file), &sb);
+           if (rc < 0) {
+                           __android_log_write(ANDROID_LOG_ERROR, "HOWDY", "stat problems");
+
+           }
+    */
+
+    char *password = "";
+    ret = ssh_pki_export_privkey_file(key, password, NULL, NULL, private_key_path);
+    if (ret != SSH_OK) {
+        __android_log_print(ANDROID_LOG_ERROR, "HOWDY", "Could not write private key %d", ret);
+        return ret;
+    }
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", "Private key exported");
+
+    ret = ssh_pki_export_pubkey_file(key, public_key_path);
+    if (ret != SSH_OK) {
+        return ret;
+    }
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", "Public key exported");
+
+    ssh_key_free(key);
+
+    change_pubickey_comment(public_key_path, comment);
+
+    // Change file permissions
+    char mode[] = "0600";
+    int modeInt = strtol(mode, 0, 8);
+    chmod(private_key_path, modeInt);
+
+    return 0;
+}
+
+void ssh_log_jni_callback(int priority, const char *function, const char *buffer, void *userdata)
+{
+    __android_log_print(ANDROID_LOG_ERROR, "SSH_HOWDY", "P%d : %s : %s", priority, function, buffer);
+}
+
+JNIEXPORT jstring JNICALL
+Java_io_gitjournal_gitjournal_Git_generateKeys(
+        JNIEnv *env,
+        jobject this_obj,
+        jstring jni_private_key_path,
+        jstring jni_public_key_path,
+        jstring jni_comment)
+{
+    const char *private_key_path = (*env)->GetStringUTFChars(env, jni_private_key_path, 0);
+    const char *public_key_path = (*env)->GetStringUTFChars(env, jni_public_key_path, 0);
+    const char *comment = (*env)->GetStringUTFChars(env, jni_comment, 0);
+
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", "Error msg");
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", private_key_path);
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", public_key_path);
+    __android_log_write(ANDROID_LOG_ERROR, "HOWDY", comment);
+
+    // Debugging
+    ssh_set_log_level(SSH_LOG_FUNCTIONS);
+    ssh_set_log_callback(ssh_log_jni_callback);
+    ssh_set_log_level(SSH_LOG_FUNCTIONS);
+
+    int ret = generate_keys(private_key_path, public_key_path, comment);
+    if (ret != 0) {
+        return (*env)->NewStringUTF(env, "Error Generating PublicKeys");
+    }
+
+    return (*env)->NewStringUTF(env, "");
+}

android/app/src/main/cpp/native-lib.cpp

@@ -1,36 +0,0 @@
-#include <jni.h>
-#include <string>
-#include <stdlib.h>
-
-#include <openssl/err.h>
-#include <openssl/crypto.h>
-#include <libssh2.h>
-#include <git2.h>
-
-extern "C" JNIEXPORT jstring JNICALL
-Java_io_gitjournal_gitjournal_Git_stringFromJNI(
-        JNIEnv *env,
-        jobject /* this */) {
-
-    ERR_load_crypto_strings();
-    const char *openssl_version = OpenSSL_version(0);
-    const char *ssh2_version = libssh2_version(0);
-
-    std::string hello = "Hello from C++: ";
-    hello += openssl_version;
-    hello += " SSH Version: ";
-    hello += ssh2_version;
-
-    git_libgit2_init();
-    int major;
-    int minor;
-    int patch;
-    git_libgit2_version(&major, &minor, &patch);
-
-    hello += " Git version: ";
-    char n_str[20];
-    sprintf(n_str, "%d.%d.%d", major, minor, patch);
-    hello += n_str;
-
-    return env->NewStringUTF(hello.c_str());
-}

android/app/src/main/java/io/gitjournal/gitjournal/Git.java

@@ -5,9 +5,5 @@ public class Git {
         System.loadLibrary("native-lib");
     }
 
-    /**
+    public native String generateKeys(String privateKeyPath, String publicKeyPath, String comment);
-     * A native method that is implemented by the 'native-lib' native library,
-     * which is packaged with this application.
-     */
-    public native String stringFromJNI();
 }

android/app/src/main/java/io/gitjournal/gitjournal/MainActivity.java

@@ -26,9 +26,6 @@ public class MainActivity extends FlutterActivity implements MethodCallHandler {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
-        Git git = new Git();
-        Log.d("VISH", git.stringFromJNI());
-
         super.onCreate(savedInstanceState);
         GeneratedPluginRegistrant.registerWith(this);