Crypt remote: 4 files consistently fail with "failed to authenticate decrypted block" near EOF while 2,512 others decrypt fine

What is the problem you are having with rclone?

I have an rclone crypt remote backed by pCloud. Out of approximately 2,516 files in one folder, exactly 4 files consistently fail to decrypt with:

failed to authenticate decrypted block - bad password?

The remaining 2,512 files decrypt and copy successfully using the same crypt remote and configuration.

The issue reproduces:

  • through rclone copy
  • through an rclone mount
  • on both rclone v1.68.2 and v1.74.4

The affected files are:

20160916_080511.mp4
20160916_081502.jpg
20160916_081503.jpg
20160916_081503(0).jpg

An interesting observation is that the failure always occurs near the end of the file.

For example:

JPEG

  • Total size: 3,653,616 bytes
  • Failure occurs after reading: 3,604,480 bytes
  • Remaining: 49,136 bytes

MP4

  • Total size: 12,828,656 bytes
  • Failure occurs after reading: 12,779,520 bytes
  • Remaining: 49,136 bytes

So two different file types fail with exactly the same number of bytes remaining.

These files were uploaded years ago using rclone crypt. As far as I remember they were uploaded in the same batch as the surrounding files, which decrypt correctly.

Run the command 'rclone version' and share the full output of the command.

rclone v1.74.4

  • os/version: Microsoft Windows 11 Pro 25H2 25H2 (64 bit)
  • os/kernel: 10.0.26200.8894 (x86_64)
  • os/type: windows
  • os/arch: amd64
  • go/version: go1.26.5
  • go/linking: static
  • go/tags: cmount

Which cloud storage system are you using? (eg Google Drive)

pCloud

The command you were trying to run (eg rclone copy /tmp remote:tmp)

rclone copy "encrypted-pcloud:1_Personal/SAMSUNG-SM-G935A/Camera/20160916_081502.jpg" "S:\Recovery" -vv

The rclone config contents with secrets removed.

[pcloud_default]
type = pcloud
hostname = api.pcloud.com
token = REDACTED

[encrypted-pcloud]
type = crypt
remote = pcloud_default:encrypted
password = REDACTED
password2 = REDACTED

A log from the command with the -vv flag

2026/07/23 12:35:45 DEBUG : rclone: Version "v1.74.4" starting with parameters ["rclone" "copy" "encrypted-pcloud:1_Personal/SAMSUNG-SM-G935A/Camera/20160916_081502.jpg" "S:\\Recovery" "-vv"]
2026/07/23 12:35:45 DEBUG : Creating backend with remote "encrypted-pcloud:1_Personal/SAMSUNG-SM-G935A/Camera/20160916_081502.jpg"
2026/07/23 12:35:45 DEBUG : Using config file from "C:\\Users\\navee\\Documents\\rclone-v1.74.4-windows-amd64\\rclone.conf"
2026/07/23 12:35:45 DEBUG : Creating backend with remote "pcloud_default:encrypted/286ihl5nm3jmfvpmlfjlb4vit8/jb96b85q2ck006mku64u3uj8mnrkcdaheg74lj695k1cmd3emai0/j6dsa6dpj3lh7knqks1ef88qhs/tuhbi98hnc9vetkuq6fuf8echgegvp8s90uikv7eh5sc9nri9rcg"
2026/07/23 12:35:48 DEBUG : fs cache: renaming child cache item "pcloud_default:encrypted/286ihl5nm3jmfvpmlfjlb4vit8/jb96b85q2ck006mku64u3uj8mnrkcdaheg74lj695k1cmd3emai0/j6dsa6dpj3lh7knqks1ef88qhs/tuhbi98hnc9vetkuq6fuf8echgegvp8s90uikv7eh5sc9nri9rcg" to be canonical for parent "pcloud_default:encrypted/286ihl5nm3jmfvpmlfjlb4vit8/jb96b85q2ck006mku64u3uj8mnrkcdaheg74lj695k1cmd3emai0/j6dsa6dpj3lh7knqks1ef88qhs"
2026/07/23 12:35:48 DEBUG : fs cache: renaming child cache item "encrypted-pcloud:1_Personal/SAMSUNG-SM-G935A/Camera/20160916_081502.jpg" to be canonical for parent "encrypted-pcloud:1_Personal/SAMSUNG-SM-G935A/Camera"
2026/07/23 12:35:48 DEBUG : Creating backend with remote "S:\\Recovery"
2026/07/23 12:35:48 DEBUG : fs cache: renaming cache item "S:\\Recovery" to be canonical "//?/S:/Recovery"
2026/07/23 12:35:49 DEBUG : 20160916_081502.jpg: Need to transfer - File not found at Destination
2026/07/23 12:35:49 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:50 +0000": parsing time "Thu, 23 Jul 2026 16:35:50 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:50 +0000" as " "
2026/07/23 12:35:49 DEBUG : 20160916_081502.jpg: Reopening on read failure after offset 3604480 bytes: retry 1/10: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:49 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:50 +0000": parsing time "Thu, 23 Jul 2026 16:35:50 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:50 +0000" as " "
2026/07/23 12:35:49 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:50 +0000": parsing time "Thu, 23 Jul 2026 16:35:50 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:50 +0000" as " "
2026/07/23 12:35:49 DEBUG : 20160916_081502.jpg: Reopen failed after offset 3604480 bytes read: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:49 NOTICE: 20160916_081502.jpg.22a4b265.partial: Removing partially written file on error: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:49 ERROR : 20160916_081502.jpg: Failed to copy: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:49 ERROR : Attempt 1/3 failed with 1 errors and: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:50 DEBUG : 20160916_081502.jpg: Need to transfer - File not found at Destination
2026/07/23 12:35:50 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:50 +0000": parsing time "Thu, 23 Jul 2026 16:35:50 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:50 +0000" as " "
2026/07/23 12:35:50 DEBUG : 20160916_081502.jpg: Reopening on read failure after offset 3604480 bytes: retry 1/10: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:50 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:51 +0000": parsing time "Thu, 23 Jul 2026 16:35:51 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:51 +0000" as " "
2026/07/23 12:35:50 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:51 +0000": parsing time "Thu, 23 Jul 2026 16:35:51 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:51 +0000" as " "
2026/07/23 12:35:50 DEBUG : 20160916_081502.jpg: Reopen failed after offset 3604480 bytes read: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:50 NOTICE: 20160916_081502.jpg.22a4b265.partial: Removing partially written file on error: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:50 ERROR : 20160916_081502.jpg: Failed to copy: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:50 ERROR : Attempt 2/3 failed with 1 errors and: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:50 DEBUG : 20160916_081502.jpg: Need to transfer - File not found at Destination
2026/07/23 12:35:51 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:51 +0000": parsing time "Thu, 23 Jul 2026 16:35:51 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:51 +0000" as " "
2026/07/23 12:35:51 DEBUG : 20160916_081502.jpg: Reopening on read failure after offset 3604480 bytes: retry 1/10: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:51 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:51 +0000": parsing time "Thu, 23 Jul 2026 16:35:51 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:51 +0000" as " "
2026/07/23 12:35:51 DEBUG : Couldn't parse Date: from server pnyc1.pcloud.com: "Thu, 23 Jul 2026 16:35:51 +0000": parsing time "Thu, 23 Jul 2026 16:35:51 +0000" as "Mon Jan _2 15:04:05 2006": cannot parse ", 23 Jul 2026 16:35:51 +0000" as " "
2026/07/23 12:35:51 DEBUG : 20160916_081502.jpg: Reopen failed after offset 3604480 bytes read: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:51 NOTICE: 20160916_081502.jpg.22a4b265.partial: Removing partially written file on error: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:51 ERROR : 20160916_081502.jpg: Failed to copy: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:51 ERROR : Attempt 3/3 failed with 1 errors and: failed to authenticate decrypted block - bad password?
2026/07/23 12:35:51 INFO  :
Transferred:       10.312 MiB / 10.312 MiB, 100%, 0 B/s, ETA -
Errors:                 1 (retrying may help)
Elapsed time:         1.9s

2026/07/23 12:35:51 DEBUG : 6 go routines active
2026/07/23 12:35:51 NOTICE: Failed to copy: failed to authenticate decrypted block - bad password?

Question: Is this pattern (successful decryption until exactly 49,136 bytes remain, followed by failed to authenticate decrypted block) indicative of corruption/truncation of the final encrypted block, or is there another likely explanation?

welcome to the forum,

Couldn't parse Date

Can you try to fix that issue, then try to copy the files.
might test --crypt-pass-bad-blocks, see what happens.