From cefb0de23f0a303b3fb061b14139f8edab21a230 Mon Sep 17 00:00:00 2001
From: bigbiff <bigbiff@teamw.in>
Date: Sun, 15 Aug 2021 18:52:04 -0400
Subject: [PATCH] fscrypt policy: don't bail restore if we cannot lookup policy

When TWRP is unable to lookup a fscrypt policy, we should not bail
the entire restore. Let's note that we had an issue with the lookup
in the log and continue restoring.

Change-Id: Ida80458356c12f81ff47f583beb05dd392486a0d
---
 libtar/append.c  |  1 -
 libtar/extract.c | 19 ++++++++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/libtar/append.c b/libtar/append.c
index 6f0b2527..dff0f88d 100755
--- a/libtar/append.c
+++ b/libtar/append.c
@@ -185,7 +185,6 @@ tar_append_file(TAR *t, const char *realname, const char *savename)
 				printf("failed to lookup fscrypt tar policy for '%s' - '%s'\n", realname, policy_hex);
 				free(t->th_buf.fep);
 				t->th_buf.fep = NULL;
-				return -1;
 			}
 		}
 		else {
diff --git a/libtar/extract.c b/libtar/extract.c
index 65ea1d16..08e2914c 100755
--- a/libtar/extract.c
+++ b/libtar/extract.c
@@ -570,6 +570,7 @@ tar_extract_dir(TAR *t, const char *realname)
 #endif
 		printf("tar_extract_dir(): restoring fscrypt policy %s to dir %s\n", (char *)policy_hex, realname);
 #endif
+		bool policy_lookup_error = false;
 #ifdef USE_FSCRYPT_POLICY_V1
 		uint8_t binary_policy[FS_KEY_DESCRIPTOR_SIZE];
 		memset(&binary_policy, 0, FS_KEY_DESCRIPTOR_SIZE);
@@ -581,24 +582,28 @@ tar_extract_dir(TAR *t, const char *realname)
 #ifdef USE_FSCRYPT_POLICY_V1
 		if (!lookup_ref_tar(t->th_buf.fep->master_key_descriptor, &binary_policy[0])) {
 			printf("error looking up fscrypt policy for '%s' - %s\n", realname, t->th_buf.fep->master_key_descriptor);
-			return -1;
+			policy_lookup_error = true;
 		}
 		memcpy(&t->th_buf.fep->master_key_descriptor, binary_policy, FS_KEY_DESCRIPTOR_SIZE);
 		bytes_to_hex(t->th_buf.fep->master_key_descriptor, FS_KEY_DESCRIPTOR_SIZE, policy_hex);
 #else
 		if (!lookup_ref_tar(t->th_buf.fep->master_key_identifier, &binary_policy[0])) {
 			printf("error looking up fscrypt policy for '%s' - %s\n", realname, t->th_buf.fep->master_key_identifier);
-			return -1;
+			policy_lookup_error = true;
 		}
 		memcpy(&t->th_buf.fep->master_key_identifier, binary_policy, FSCRYPT_KEY_IDENTIFIER_SIZE);
 		bytes_to_hex(t->th_buf.fep->master_key_identifier, FSCRYPT_KEY_IDENTIFIER_SIZE, policy_hex);
 #endif
-		printf("attempting to restore policy: %s\n", policy_hex);
-		if (!fscrypt_policy_set_struct(realname, t->th_buf.fep))
+		if (!policy_lookup_error) 
 		{
-			printf("tar_extract_file(): failed to restore fscrypt policy to dir '%s' '%s'!!!\n", realname, policy_hex);
-			//return -1; // This may not be an error in some cases, so log and ignore
-		}
+			printf("attempting to restore policy: %s\n", policy_hex);
+			if (!fscrypt_policy_set_struct(realname, t->th_buf.fep))
+			{
+				printf("tar_extract_file(): failed to restore fscrypt policy to dir '%s' '%s'!!!\n", realname, policy_hex);
+				//return -1; // This may not be an error in some cases, so log and ignore
+			}
+		} else
+			printf("No policy was found. Continuing restore.");
 	}
 	else
 		printf("NULL FSCRYPT\n");