CSSCurrent en:Advanced Configuration

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Cryptshare System Properties

By placing an additional settings file called 'cryptshare.properties' into the Cryptshare installation folder, certain parts of the Cryptshare Server can be influenced in their behaviour. These settings are intended for use when experiencing problems with the Cryptshare Server. As of now, settings regarding the following parts of the application can be made:

  • Optimizing the database
  • Skipping of certain operations during cleanup (Cleanup Task)
  • Sizing of the thread pool for encryption threads
  • Maximum timeout for a pending Backup Task
cryptshare.properties does not exist
By default, the 'cryptshare.properties' file is not part of the Cryptshare Installation and has to be created first:
  1. Navigate to the Cryptshare installation folder and create the file 'cryptshare.properties'
  2. Add the desired configuration flags to the file. One flag per line:


  1. Save the changes
Instant auto-reload
Please note, that when introducing or changing the contents of this file, a system restart is required. The settings file will automatically be re-initialized upon change but there are Values which require a restart..
cryptshare.properties - Example file
 # EN: Documentation see here: https://documentation.cryptshare.com/w/CSSCurrent_en:Advanced_Configuration
 mainPoolSize = 150


Database Connection Pool

Depending on the requirements of your Cryptshare Server and the expected load it might be necessary to increase resource allocation for the database.

Calculating Pool Sizes

The following formula can be used to calculate an appropriate pool size:

(cpu_core_count * 2) + 1

Here are some examples with the pool size rounded up:

CPU Cores 2 4 8 16
Pool Size 5 10 20 35
Note that both a too small or too large pool size can negatively impact performance. If the pool size is too small, the available system resources will not be fully utilized and requests may have to wait until the pool frees connections. If the pool size is too high, requests may slow down as the CPU cores must be shared.
Database Optimization
Default Setting: '5' (for both) <int>: Numeric value specifying the connection pool size

Skipping Cleanup Task Steps

The cleanup task consists of several steps executed in subsequent order. If due to database inconsistencies or internal database errors one of these steps cannot finish its operations properly or gets stuck, the respective step can be skipped in order to be able to finish the rest of the cleanup operation.

Please note that skipping cleanup steps is not recommended unless you are experiencing issues which cause the cleanup task not to finish its cleanup procedure.

Steps which can be skipped

In order to find out which cleanup step is responsible for errors you can check the system log and deactivate this step by applying the respective Cryptshare system property.

LockData Cleanup Step

cleanup.skip.lockData = <true|false>

LockData is an internal record keeping track of wrong-password attempts within the Cryptshare download section. This data will be removed from the system as soon as it is not required any more. For instance if a transfer record has been archived.

This step can be skipped without risk. However, if not active, the database will fill up with lock data records not required anymore.

Verification Cleanup Step

cleanup.skip.verifications = <true|false>

Verification records are the server-side representation of verified users. Expired verifications will be removed from the system.

This step can be skipped without risk. However, if not active, the database will fill up with expired verification records.

Timeout for pending BackupTask

If the database backup has been enabled, the backup task is configured to wait for other tasks to finish their operations before executing the backup. However it can happen, that theses tasks are not finished properly so that the backup task would be waiting infinitely. The maximum timeout setting configures the backup task to continue with its operations regardless of the fact that there are still running tasks. The default value is set to 60 minutes.

<int> : Numeric value specifying the timeout in minutes, i.e. '60'
Default: 60

Performance Adjustment

Please do not change these settings unless you are experiencing problems.

Encryption Thread Pool

The size for the Cryptshare encryption thread pool defines the amount of parallel file encryption operations for Cryptshare Transfers. The default setting is set to 30. This means, that on a Cryptshare server with this setting 30 parallel encryption processes can be initiated. The next process which would exceed this maximum will be put into a queue and will be started as soon as a thread from this pool is available again. This parameter not only influences the size of the encryption thread pool, but also affects the number of parallel gathering processes of the pre-processing result, if the display of pre-processing results is activated.

Please note, that this setting can have a noticable impact on CPU and memory usage.
  • A high value for this setting will INCREASE the CPU usage
  • A low value for this setting will DECREASE the CPU usage
Parameter for the encryption thread pool size
<int>: Numeric value specifying the thread pool size
Default: 30

Mailing Thread Pool

The size for the Cryptshare mailing thread pool defines the amount of parallel mail sending operations. Please note that email servers often only allow a limited number of simultaneous connections. If you adjust this parameter, make sure that your email server is able to handle this increased quantity.

Parameter for the mail thread pool size
<int>: Numeric value specifying the thread pool size
Default: 5

Download Decryption Buffer

Cryptshare works with an AES algorithm. This algorithm is known to be much more resource-intensive when decrypting than when encrypting. Depending on how the system is mainly used, a change of the decryption buffer size can either increase or decrease CPU/Memory consumption.

The default setting for the decryption buffer is 2MB. This is a good setting for a server handling both, small and large files. If the server however is mostly handling larger files, increasing the buffer size can considerably improve the CPU consumption. However, this will increase memory usage.

Please note, that this setting should be handled with caution as it can have a massive impact on CPU and memory use.
Parameter for the decryption buffer size
<int>: Numeric value specifying the buffer size in bytes.
Default: 2097152 (2MB)

Download Delay

Under high load, the Cryptshare Server delays the decryption of files being downloaded to improve responsiveness of the Cryptshare Server. This behavior can be disabled if it causes problems.

This property can be set to "false" without a server restart and it will be instantly applied. When setting it to "true", a restart is required.
Parameter for the decryption buffer size

HTML5 Transfer Settings

HTML5 Parallel Upload Streams

Please do only change this parameter if experiencing performance issues such as interrupted HTML5 uploads due to too high I/O activity or CPU load. Please also note, that decreasing this parameter will also slow down the HTML5 upload rate.
Parameter for parallel HTML5 upload streams
<int>: Numeric value specifying the maximum amount of parallel HTML5 upload streams.

Default: 5

Maximum: 5

HTML5 Cleanup Tracker Timeout

In HTML5 transfer mode every upload stream is kept under surveillance by a Cleanup Tracker which makes sure, that upload files of interrupted transfers will be removed from the system.

On bad internet connections however, the default timeout setting of 10 minutes can be too short and ongoing HTML5 uploads are interrupted before the transfer is complete.

In order to avoid this behavior, the default timeout setting can be increased.
Cleanup Tracker Timeout
upload.html.timeout = <timeout in minutes>
<timeout in minutes>: Numeric Integer value specifying the timeout value in minutes

Default: 10

Allowed: Integer between 1 and 60

HTML5 Client Error Count

The HTML5 transfer mode is capable of proceeding a transfer even when the http connection temporarily gets interrupted or is so bad that many requests are running into a timeout.

If such an error occurs the client will try to re-send the failed packages until either all packages were transferred successfully or the error counter has exceeded. In case the error count has exceeded the client will cancel the transfer.

If your clients often run into this problem it is possible to increase the maximum error count so that clients won't cancel a transfer so quickly.
HTML5 Client Error Count
upload.html.maxerrors = <20-5000>
<int>: Number to set for the error count

Default: 100

Allowed: 20-5000

LDAP Settings

Connection pool

To increase the performance of LDAP requests, Cryptshare uses a pool of already established connections. They can be used and re-used for LDAP requests. It is possible to configure the minimum (initial) and maximum number of simultaneously established connections.

Initial number of connections
Maximum number of connections
<int>: Numeric integer value that specifies the number of connections.

Default initial number: 5

Default maximum number: 20


A timeout specifies the maximum time that is allowed to perform a certain task. Regarding LDAP, there are two timeouts that can be configured: Connection timeout: Allowed time to establish a connection to an LDAP server. Response timeout: Allowed time recieve a response to a submitted request.

Connection timeout
Request timeout
<int>: Numeric integer value that specifies the time in milliseconds.

Default connection timeout: 5000 (5 seconds)

Default response timeout: 20000 (20 seconds)


Some LDAP directories are partitioned / distributed and contain entries that refer to other directories (so-called referrals). Optionally, the automatic resolution of these references through an additional connection can be enabled. If the resolved reference again contains a reference, this will not be resolved.

Referral resolution
Default: false (disabled)

Security Setting Rate Limiting

Rate Limiting for Requesting a Verification Code

In order to limit the number of verification requests per minute to prevent DoS attacks and mail flooding, rate limiting for requesting a verification code is active. The number of verification codes that can be requested per minute is limited to 25 by default.

For handling rate limit requests, additional response headers are available. See Rate limiting
Parameter for setting a rate limit for requesting a verification code
<int>: Numeric integer value that specifies the number of verification code requests per minute.

Default: 25

This feature is deactivatable by setting the value to 0.

Content Security Policy

Content Security Policy (CSP) is an additional security mechanism that helps to detect and mitigate certain types of attacks, e.g. Cross-Site Scripting (XSS). For this purpose, a so-called CSP header can be used, which allows the client(browser) to access only certain defined resources. This can prevent e.g. an attacker from executing malicious code from an unknown source. By default, the Cryptshare server only allows the use of resources from the server's domain.

Parameter for adding other urls as resources
<string>: Comma-separated list of urls that are allowed to use for resources. Default: ""

Example: To add the additional URLS 'https://example.com' and 'https://app.example.com/images', set the value to 'https://example.com,https://app.example.com/images'

Prioritisation of file types in EML Archiving and EML Download

Priorization of file types for EML Archiving and EML Download

Using EML archiving and EML Download it is possible to set a attachment total file size limit for attachments put into the generated EML file. When the total attachment file size exceeds the set limit, files are attached to the EML file using a priorization list of file types where file type extensions at the start have a higher priority than those after them. File types not in the list have the lowest priorty. If an empty string is provided as priorization list, this file type priorization behaviour is disabled.

You can find more information for the EML Archiving in the article Activating the Archiving Feature.
Parameter for setting the priorization list of attachments when reaching the file size limit
<csv>: Comma-separated list of file extensions Default: eml,pdf,docx,doc,xlsx,xls,txt,ppt,pptx

Further Configuration Flags

Cleaning up orphaned temporary upload files

While files are being uploaded during a transfer, this data is written to a temporary upload directory. Due to technical reasons it is however possible that those files are not always deleted afterwards. Therefore an additional cleanup step which is executed during the execution of the Cleanup Task takes care of those orphaned files and removes them from the disk if they are older than 24 hours.

Parameter for disabling the temporary file Cleanup Step
Default: true

Log Verbosity for ongoing uploads

In order to enable the administrator to better notice running uploads, an informal log entry is written after a certain number of upload requests. A file upload usually consists of several upload requests. The counting is done across transfers.

INFO  2016-04-29 08:45:51 CS3System - (com.cryptshare.wicket.request.HTML5FileItemFactory@1771fb9f) - Cryptshare upload in progress.

Depending on the upload activity of this server there might be too many or to few of these entries. In either way, the counter for this feature can be changed accordingly.

Parameter for controlling how many upload log-entries will be written to the log
<int>: Numeric value to set after how many upload requests a log entry should be written. Default: 1000

Performing a backup before an update

Usually before an update is performed, a rollback-compatible backup will be made. In case, there's something wrong with the backup procedure so that it avoids performing the update, this step can be disabled.

Parameter for enabling backups before an update
Default: true

Maximum File Size for the Cryptshare Content Viewer

The Content Viewer in the download section of Cryptshare only opens files smaller than 2MB. For security reasons the viewer only opens these files in memory which can massively increase the memory consumption.

Memory Consumption
Please note, that depending on your available memory and the average user load on the server memory consumption can increase drastically if you increase this setting.
This value also affects the display of the confidential message in the download page.

Increasing the maximum file size of the Content Viewer

viewer.maxSize = <int>
<int> = Integer defining the maximum file size in MB.
Default: 2

File Type Filter Max. Buffer Size

When the embedded file analysis of the file type filter is active, supported files are opened and scanned for their contents. In the case of MS Office files, this analysis can require large amounts of memory when working with larger files. If files cannot be scanned due to this, the following parameter can be set to a large value to allow scanning these files, at the cost of increased memory consumption.

Increasing the maximum buffer size when analyzing office files

fileTypeFilter.byteArrayMax= <int>
Integer defining the maximum size of the buffer to use when analyzing office files.
Default: 100000000 (100 Million Bytes = 100 MB)

Virtual Hosts Restriction

By default, the Cryptshare Server will respond to HTTP requests regardless of the contents of the 'Host'-header. To protect against Host-Header-Injection-Attacks, the server can be configured to block requests with a Host-header that is not the canonical host of this system.

Restrict Host-headers

virtualHosts.restrict= <true|false>
If Host-headers in requests should be restricted. If enabled, only the host of the configured base-URL as well as additional hosts from `virtualHosts.additional` are accepted.
Default: false
Please note that a wrong configuration can lead to the Cryptshare Server being unavailable via HTTP.

Additional Virtual Hosts

If `virtualHosts.restrict` is enabled, `virtualHosts.additional` can be used to add additional hosts the server is available under.

Add additional virtual host

virtualHosts.additional= <string>
Comma-seperated host names (besides the configured base URL) under which this Cryptshare Server is available. See https://www.eclipse.org/jetty/documentation/jetty-9/index.html#configuring-a-virtual-host for details on the syntax.
Default: ""

Example: To add the additional virtual hosts 'example.com' and 'app.example.com', set the value to 'example.com,app.example.com'