diff --git a/src/api/encryption.c b/src/api/encryption.c
deleted file mode 100644
index e576c3deceb48079aff4db30c1bf8a0a77404e1e..0000000000000000000000000000000000000000
--- a/src/api/encryption.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/**
- * Callback function that shows the current encryption status (encrypted or
- * unencrypted).
- *
- * Example output:
- * {"encryption-status":"encrypted"}
- *
- * @param[in] request incoming HTTP request
- * @param[out] response HTTP response to the request
- * @param[in] user_data extra data to pass between main thread and callbacks
- * @return internal status code
- */
-int callback_encryption(const struct _u_request * request,
- struct _u_response * response, void * user_data)
-{
- char * encryption_status;
- if (path_exists(DATA_PARTITION_DEVICE) &&
- is_encrypted_device(DATA_PARTITION_DEVICE))
- {
- encryption_status = "encrypted";
- }
- else
- {
- encryption_status = "unencrypted";
- }
- return send_simple_response(response, 200,
- "encryption-status", encryption_status);
-}
diff --git a/src/api/encryption_get.c b/src/api/encryption_get.c
new file mode 100644
index 0000000000000000000000000000000000000000..4f02c0685b95096f8bbf98b0864d39b1d956dab8
--- /dev/null
+++ b/src/api/encryption_get.c
@@ -0,0 +1,65 @@
+/**
+ * Callback function that shows the current encryption status (encrypted or
+ * unencrypted).
+ *
+ * Example output:
+ * {"encryption-status":"encrypted"}
+ *
+ * @param[in] request incoming HTTP request
+ * @param[out] response HTTP response to the request
+ * @param[in] user_data extra data to pass between main thread and callbacks
+ * @return internal status code
+ */
+int callback_encryption_get(const struct _u_request * request,
+ struct _u_response * response, void * user_data)
+{
+ bool encrypted;
+ bool * can_encrypt_nullable = NULL;
+ bool can_encrypt = true;
+ json_t * messages = json_array();
+
+ if (path_exists(DATA_PARTITION_DEVICE) &&
+ is_encrypted_device(DATA_PARTITION_DEVICE))
+ {
+ encrypted = true;
+ }
+ else
+ {
+ encrypted = false;
+ can_encrypt_nullable = &can_encrypt;
+
+ // Mount the filesystem on the unencrypted device.
+ int r = temporary_mount(ROOT_DEVICE, UNENCRYPTED_TMP_MOUNTPOINT,
+ FILESYSTEM_TYPE);
+ if (r != 0)
+ {
+ printf("mounting root device failed: return code %d\n", r);
+ return send_simple_response(response, 500, "error",
+ "mounting root device failed");
+ }
+ bool fits = filesystem_fits_in_memory(UNENCRYPTED_TMP_MOUNTPOINT,
+ MEMORY_USAGE, true);
+ umount(UNENCRYPTED_TMP_MOUNTPOINT);
+ if (! fits)
+ {
+ can_encrypt = false;
+ json_array_append_new(messages, json_string(
+ "existing files do not fit in memory"));
+ }
+ }
+
+ json_t * json_body = NULL;
+ json_body = json_object();
+
+ json_object_set_new(json_body, "encrypted",
+ encrypted ? json_true() : json_false());
+
+ json_object_set_new(json_body, "can-encrypt",
+ can_encrypt_nullable == NULL ? json_null() :
+ (can_encrypt ? json_true() : json_false()));
+ json_object_set_new(json_body, "messages", messages);
+
+ ulfius_set_json_body_response(response, 200, json_body);
+ json_decref(json_body);
+ return U_CALLBACK_CONTINUE;
+}
diff --git a/src/api/encryption_init.c b/src/api/encryption_init_post.c
similarity index 93%
rename from src/api/encryption_init.c
rename to src/api/encryption_init_post.c
index 5f2880be01f23dd315022b82244b1fa6ca00578f..fc9e797386a944027fb8589fd99bbb3552096a37 100644
--- a/src/api/encryption_init.c
+++ b/src/api/encryption_init_post.c
@@ -27,7 +27,7 @@
* @param[in] user_data extra data to pass between handler and main thread
* @return internal status code
*/
-int callback_encryption_init(const struct _u_request * request,
+int callback_encryption_init_post(const struct _u_request * request,
struct _u_response * response, void * user_data)
{
bool * reboot = (bool *)user_data;
@@ -62,23 +62,10 @@ int callback_encryption_init(const struct _u_request * request,
"mounting root device failed");
}
- // Determine the filesystem usage of the device to be encrypted.
- unsigned long size = filesystem_usage(UNENCRYPTED_TMP_MOUNTPOINT);
- if (size < 0)
- {
- // Something went wrong in determining the filesystem usage.
- printf("determining filesystem usage failed: return code %lu\n", size);
- return send_simple_response(response, 500, "error",
- "determining filesystem usage failed");
- }
- printf("root device usage: %lu bytes\n", size);
-
- // Determine the available memory.
- unsigned long memory = available_memory();
-
- double projected_usage = (double)size / (double)memory;
- printf("projected memory usage: %.3f\n", projected_usage);
- if (projected_usage > MEMORY_USAGE)
+ // Determine if the files on the unencrypted device would fit in memory.
+ bool fits = filesystem_fits_in_memory(UNENCRYPTED_TMP_MOUNTPOINT,
+ MEMORY_USAGE, true);
+ if (! fits)
{
// Projected memory usage is really high, so abort.
return send_simple_response(response, 500, "error",
diff --git a/src/api/encryption_remove.c b/src/api/encryption_remove_post.c
similarity index 99%
rename from src/api/encryption_remove.c
rename to src/api/encryption_remove_post.c
index f49529aa444f7f0fe0c72518d075ac01329deee4..e76e357bff5302490fa13f05e660f32dc432930f 100644
--- a/src/api/encryption_remove.c
+++ b/src/api/encryption_remove_post.c
@@ -22,7 +22,7 @@
* @param[in] user_data extra data to pass between handler and main thread
* @return internal status code
*/
-int callback_encryption_remove(const struct _u_request * request,
+int callback_encryption_remove_post(const struct _u_request * request,
struct _u_response * response, void * user_data)
{
bool * reboot = (bool *)user_data;
diff --git a/src/api/encryption_unlock.c b/src/api/encryption_unlock_post.c
similarity index 95%
rename from src/api/encryption_unlock.c
rename to src/api/encryption_unlock_post.c
index fd20287806e66b2579528fae256760feaf02681d..83340837691ef09686d9929c74e996571247b5b9 100644
--- a/src/api/encryption_unlock.c
+++ b/src/api/encryption_unlock_post.c
@@ -6,7 +6,7 @@
* @param[in] user_data extra data to pass between main thread and callbacks
* @return internal status code
*/
-int callback_encryption_unlock(const struct _u_request * request,
+int callback_encryption_unlock_post(const struct _u_request * request,
struct _u_response * response, void * user_data)
{
json_t * json_input = ulfius_get_json_body_request(request, NULL);
diff --git a/src/auxiliary.c b/src/auxiliary.c
index 6b833d80adc22a36440437496bb7fc0936e4ebb1..9773c09528bd10ef5120a9bb745b9fc733a5981e 100644
--- a/src/auxiliary.c
+++ b/src/auxiliary.c
@@ -111,6 +111,45 @@ unsigned long filesystem_usage(const char * path)
return (s.f_blocks - s.f_bfree) * s.f_bsize;
}
+/**
+ * Check if the files on the given filesystem would fit into memory.
+ * @param path Path of the mounted filesystem.
+ * @param safety_margin Fraction (between zero and one) of free memory to
+ deem available for containing the files.
+ * @param debug Whether to print debug messages.
+ * @return Whether the filesystem seems to fit into memory.
+ */
+bool filesystem_fits_in_memory(const char * path, double safety_margin,
+ bool debug)
+{
+ // Determine the filesystem usage of the device to be encrypted.
+ unsigned long size = filesystem_usage(path);
+ if (size < 0)
+ {
+ // Something went wrong in determining the filesystem usage.
+ // Return false as a precaution.
+ if (debug)
+ {
+ printf("Determining file system usage failed (size: %lu)\n", size);
+ }
+ return false;
+ }
+ if (debug)
+ {
+ printf("file system usage: %lu bytes\n", size);
+ }
+
+ // Determine the available memory.
+ unsigned long memory = available_memory();
+
+ double projected_usage = (double)size / (double)memory;
+ if (debug)
+ {
+ printf("projected memory usage: %.3f\n", projected_usage);
+ }
+ return (projected_usage <= safety_margin);
+}
+
/**
* Mount a filesystem; create the mount target if it doesn't exist.
* @param device_path Path to the device to mount.
diff --git a/src/cryptops-api.c b/src/cryptops-api.c
index 6b1e6d263828573c9e4c970327c40145c0b51e2d..114850423a3f74cb710a1a3edb661e0f6160b9d7 100644
--- a/src/cryptops-api.c
+++ b/src/cryptops-api.c
@@ -6,10 +6,10 @@
#include <auxiliary.c>
#include <encryption_functions.c>
#include <api/default.c>
-#include <api/encryption.c>
-#include <api/encryption_init.c>
-#include <api/encryption_remove.c>
-#include <api/encryption_unlock.c>
+#include <api/encryption_get.c>
+#include <api/encryption_init_post.c>
+#include <api/encryption_remove_post.c>
+#include <api/encryption_unlock_post.c>
#include <api/encryption_keys_put.c>
#include <api/ssh_keys_get.c>
@@ -41,16 +41,16 @@ int main(int argc, char ** argv)
bool reboot = false;
ulfius_add_endpoint_by_val(&instance, "GET" , PREFIX,
"/encryption",
- 0, &callback_encryption, NULL);
+ 0, &callback_encryption_get, NULL);
ulfius_add_endpoint_by_val(&instance, "POST", PREFIX,
"/encryption/init",
- 0, &callback_encryption_init, &reboot);
+ 0, &callback_encryption_init_post, &reboot);
ulfius_add_endpoint_by_val(&instance, "POST", PREFIX,
"/encryption/remove",
- 0, &callback_encryption_remove, &reboot);
+ 0, &callback_encryption_remove_post, &reboot);
ulfius_add_endpoint_by_val(&instance, "POST", PREFIX,
"/encryption/unlock",
- 0, &callback_encryption_unlock, NULL);
+ 0, &callback_encryption_unlock_post, NULL);
ulfius_add_endpoint_by_val(&instance, "PUT" , PREFIX,
"/encryption/keys/:slot",
0, &callback_encryption_keys_put, NULL);