Add crypt_backend_destroy() function and cll it as library destructor.

lib/crypto_backend/crypto_backend.h

@@ -31,6 +31,7 @@ struct crypt_cipher;
 struct crypt_storage;
 
 int crypt_backend_init(struct crypt_device *ctx);
+void crypt_backend_destroy(void);
 
 #define CRYPT_BACKEND_KERNEL (1 << 0)	/* Crypto uses kernel part, for benchmark */
 

lib/crypto_backend/crypto_gcrypt.c

@@ -121,6 +121,14 @@ int crypt_backend_init(struct crypt_device *ctx)
 	return 0;
 }
 
+void crypt_backend_destroy(void)
+{
+	if (crypto_backend_initialised)
+		gcry_control(GCRYCTL_TERM_SECMEM);
+
+	crypto_backend_initialised = 0;
+}
+
 const char *crypt_backend_version(void)
 {
 	return crypto_backend_initialised ? version : "";

lib/crypto_backend/crypto_kernel.c

@@ -38,7 +38,7 @@
 #endif
 
 static int crypto_backend_initialised = 0;
-static char version[64];
+static char version[256];
 
 struct hash_alg {
 	const char *name;
@@ -126,6 +126,11 @@ int crypt_backend_init(struct crypt_device *ctx)
 	return 0;
 }
 
+void crypt_backend_destroy(void)
+{
+	crypto_backend_initialised = 0;
+}
+
 uint32_t crypt_backend_flags(void)
 {
 	return CRYPT_BACKEND_KERNEL;

lib/crypto_backend/crypto_nettle.c

@@ -143,6 +143,11 @@ int crypt_backend_init(struct crypt_device *ctx)
 	return 0;
 }
 
+void crypt_backend_destroy(void)
+{
+	return;
+}
+
 const char *crypt_backend_version(void)
 {
 	return version;

lib/crypto_backend/crypto_nss.c

@@ -88,6 +88,11 @@ int crypt_backend_init(struct crypt_device *ctx)
 	return 0;
 }
 
+void crypt_backend_destroy(void)
+{
+	crypto_backend_initialised = 0;
+}
+
 uint32_t crypt_backend_flags(void)
 {
 	return 0;

lib/crypto_backend/crypto_openssl.c

@@ -116,6 +116,11 @@ int crypt_backend_init(struct crypt_device *ctx)
 	return 0;
 }
 
+void crypt_backend_destroy(void)
+{
+	crypto_backend_initialised = 0;
+}
+
 uint32_t crypt_backend_flags(void)
 {
 	return 0;

lib/setup.c

@@ -3062,3 +3062,8 @@ int crypt_get_integrity_info(struct crypt_device *cd,
 
 	return -ENOTSUP;
 }
+
+static void __attribute__((destructor)) libcryptsetup_exit(void)
+{
+	crypt_backend_destroy();
+}