BranchesTags

Repository files navigation

jumphost

These scripts produce a minimal OpenSSH jump host, which will accept signed user keys and allow them to transfer to another host inside the network. The build system uses linux-builder to create a custom kernel and initrd with only the sshd program.

Goals:

  • Diskless image
  • Immutable system
  • Network logging
  • No shell for accidental code execution
  • Minimal attack surface

Building

git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt

virsh create jump/jump.xml

Signed user keys

Every user logs into the jump host as user jump. Passwords are not allowed. Interactive sessions are not allowed. Only proxy commands via the ssh -J jump@jumphost user@other-host are allowed.

The jumphost has a public key of the user CA that will sign acceptable user keys. This CA is fixed at image build time; to change the CA requires rebuilding the jump host system image. The login attempts are sent via syslog to the network logging host.

Signed host keys

The jumphost's host key is also signed by a host CA, so that users connecting can ensure that they trust it without having to TOFU (Trust On First Use) the key.

You can add it to your user ssh config by running:

echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About

ssh jump host appliance

Resources

Readme
Activity
Custom properties

Stars

0 stars

Watchers

0 watching

Forks

0 forks
Report repository

Releases

Packages

Contributors

Languages

, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
BranchesTags
Repository files navigation
jumphost
These scripts produce a minimal OpenSSH jump host, which will
accept signed user keys and allow them to transfer to another
host inside the network. The build system uses
linux-builder
to create a custom kernel and initrd with only the sshd program.
Goals:
  •  Diskless image
  •  Immutable system
  •  Network logging
  •  No shell for accidental code execution
  •  Minimal attack surface
Building
git clone --recursive https://github.com/osresearch/jumphost
cd jumphost
make keys # create CA keys and a demo user
make -j32 build/vmlinuz-jump
make qemu

Running with libvirt
virsh create jump/jump.xml

Signed user keys
Every user logs into the jump host as user jump. Passwords are not
allowed. Interactive sessions are not allowed. Only proxy commands
via the ssh -J jump@jumphost user@other-host are allowed.
The jumphost has a public key of the user CA that will sign acceptable
user keys. This CA is fixed at image build time; to change the CA requires
rebuilding the jump host system image. The login attempts are sent
via syslog to the network logging host.
Signed host keys
The jumphost's host key is also signed by a host CA, so that users
connecting can ensure that they trust it without having to TOFU
(Trust On First Use) the key.
You can add it to your user ssh config by running:
echo "@cert-authority * $(cat etc/host_ca.pub)" >> ~/.ssh/known_hosts

About
ssh jump host appliance
Resources
Readme
Activity
Custom properties
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors
Languages