tough-cookie
RFC 6265 Cookies and CookieJar for Node.js
Synopsis
var tough = require('tough-cookie')
var Cookie = tough.Cookie
var cookie = Cookie.parse(header)
cookie.value = 'somethingdifferent'
header = cookie.toString()
var cookiejar = new tough.CookieJar()
var cookie = await cookiejar.setCookie(
cookie,
'https://currentdomain.example.com/path',
)
var cookies = await cookiejar.getCookies('https://example.com/otherpath')
cookiejar.setCookie(
cookie,
'https://currentdomain.example.com/path',
function (err, cookie) {
},
)
cookiejar.getCookies('http://example.com/otherpath', function (err, cookies) {
})
Why the name? NPM modules cookie
, cookies
and cookiejar
were already taken.
Installation
It's so easy! Install with npm
or your preferred package manager.
npm install tough-cookie
Node.js Version Support
We follow the node.js release schedule and support all versions that are in Active LTS or Maintenance. We will always do a major release when dropping support for older versions of node, and we will do so in consultation with our community.
API
tough
The top-level exports from require('tough-cookie')
can all be used as pure functions and don't need to be bound.
parseDate(string)
Parse a cookie date string into a Date
. Parses according to RFC 6265 Section 5.1.1, not Date.parse()
.
formatDate(date)
Format a Date
into an RFC 822 string (the RFC 6265 recommended format).
canonicalDomain(str)
Transforms a domain name into a canonical domain name. The canonical domain name is a domain name that has been trimmed, lowercased, stripped of leading dot, and optionally punycode-encoded (Section 5.1.2 of RFC 6265). For the most part, this function is idempotent (calling the function with the output from a previous call returns the same output).
domainMatch(str, domStr[, canonicalize=true])
Answers "does this real domain match the domain in a cookie?". The str
is the "current" domain name and the domStr
is the "cookie" domain name. Matches according to RFC 6265 Section 5.1.3, but it helps to think of it as a "suffix match".
The canonicalize
parameter toggles whether the domain parameters get normalized with canonicalDomain
or not.
defaultPath(path)
Given a current request/response path, gives the path appropriate for storing in a cookie. This is basically the "directory" of a "file" in the path, but is specified by Section 5.1.4 of the RFC.
The path
parameter MUST be only the pathname part of a URI (excluding the hostname, query, fragment, and so on). This is the .pathname
property of node's uri.parse()
output.
pathMatch(reqPath, cookiePath)
Answers "does the request-path path-match a given cookie-path?" as per RFC 6265 Section 5.1.4. Returns a boolean.
This is essentially a prefix-match where cookiePath
is a prefix of reqPath
.
parse(cookieString[, options])
Alias for Cookie.parse(cookieString[, options])
.
fromJSON(string)
Alias for Cookie.fromJSON(string)
.
getPublicSuffix(hostname)
Returns the public suffix of this hostname. The public suffix is the shortest domain name upon which a cookie can be set. Returns null
if the hostname cannot have cookies set for it.
For example: www.example.com
and www.subdomain.example.com
both have public suffix example.com
.
For further information, see the Public Suffix List. This module derives its list from that site. This call is a wrapper around psl
's get
method.
cookieCompare(a, b)
For use with .sort()
, sorts a list of cookies into the recommended order given in step 2 of (RFC 6265 Section 5.4). The sort algorithm is, in order of precedence:
- Longest
.path
- oldest
.creation
(which has a 1-ms precision, same as Date
) - lowest
.creationIndex
(to get beyond the 1-ms precision)
var cookies = [
]
cookies = cookies.sort(cookieCompare)
Note: Since the JavaScript Date
is limited to a 1-ms precision, cookies within the same millisecond are entirely possible. This is especially true when using the now
option to .setCookie()
. The .creationIndex
property is a per-process global counter, assigned during construction with new Cookie()
, which preserves the spirit of the RFC sorting: older cookies go first. This works great for MemoryCookieStore
since Set-Cookie
headers are parsed in order, but is not so great for distributed systems. Sophisticated Store
s may wish to set this to some other logical clock so that if cookies A and B are created in the same millisecond, but cookie A is created before cookie B, then A.creationIndex < B.creationIndex
. If you want to alter the global counter, which you probably shouldn't do, it's stored in Cookie.cookiesCreated
.
permuteDomain(domain)
Generates a list of all possible domains that domainMatch()
the parameter. Can be handy for implementing cookie stores.
permutePath(path)
Generates a list of all possible paths that pathMatch()
the parameter. Can be handy for implementing cookie stores.
Cookie
Exported via tough.Cookie
.
Cookie.parse(cookieString[, options])
Parses a single Cookie or Set-Cookie HTTP header into a Cookie
object. Returns undefined
if the string can't be parsed.
The options parameter is not required and currently has only one property:
- loose - boolean - if
true
enable parsing of keyless cookies like =abc
and =
, which are not RFC-compliant.
If options is not an object it is ignored, which means it can be used with Array#map
.
To process the Set-Cookie header(s) on a node HTTP/HTTPS response:
if (Array.isArray(res.headers['set-cookie']))
cookies = res.headers['set-cookie'].map(Cookie.parse)
else cookies = [Cookie.parse(res.headers['set-cookie'])]
Note: In version 2.3.3, tough-cookie limited the number of spaces before the =
to 256 characters. This limitation was removed in version 2.3.4.
For more details, see issue #92.
Properties
Cookie object properties:
- key - string - the name or key of the cookie (default
""
) - value - string - the value of the cookie (default
""
) - expires -
Date
- if set, the Expires=
attribute of the cookie (defaults to the string "Infinity"
). See setExpires()
- maxAge - seconds - if set, the
Max-Age=
attribute in seconds of the cookie. Can also be set to strings "Infinity"
and "-Infinity"
for non-expiry and immediate-expiry, respectively. See setMaxAge()
- domain - string - the
Domain=
attribute of the cookie - path - string - the
Path=
of the cookie - secure - boolean - the
Secure
cookie flag - httpOnly - boolean - the
HttpOnly
cookie flag - sameSite - string - the
SameSite
cookie attribute (from RFC 6265bis); must be one of none
, lax
, or strict
- extensions -
Array
- any unrecognized cookie attributes as strings (even if equal-signs inside) - creation -
Date
- when this cookie was constructed - creationIndex - number - set at construction, used to provide greater sort precision (see
cookieCompare(a,b)
for a full explanation)
After a cookie has been passed through CookieJar.setCookie()
it has the following additional attributes:
- hostOnly - boolean - is this a host-only cookie (that is, no Domain field was set, but was instead implied).
- pathIsDefault - boolean - if true, there was no Path field on the cookie and
defaultPath()
was used to derive one. - creation -
Date
- modified from construction to when the cookie was added to the jar. - lastAccessed -
Date
- last time the cookie got accessed. Affects cookie cleaning after it is implemented. Using cookiejar.getCookies(...)
updates this attribute.
new Cookie([properties])
Receives an options object that can contain any of the above Cookie properties. Uses the default for unspecified properties.
.toString()
Encodes to a Set-Cookie header value. The Expires cookie field is set using formatDate()
, but is omitted entirely if .expires
is Infinity
.
.cookieString()
Encodes to a Cookie header value (specifically, the .key
and .value
properties joined with "="
).
.setExpires(string)
Sets the expiry based on a date-string passed through parseDate()
. If parseDate returns null
(that is, can't parse this date string), .expires
is set to "Infinity"
(a string).
.setMaxAge(number)
Sets the maxAge in seconds. Coerces -Infinity
to "-Infinity"
and Infinity
to "Infinity"
so it correctly serializes to JSON.
.expiryDate([now=Date.now()])
expiryTime()
computes the absolute unix-epoch milliseconds that this cookie expires. expiryDate()
works similarly, except it returns a Date
object. Note that in both cases the now
parameter should be milliseconds.
Max-Age takes precedence over Expires (as per the RFC). The .creation
attribute -- or, by default, the now
parameter -- is used to offset the .maxAge
attribute.
If Expires (.expires
) is set, that's returned.
Otherwise, expiryTime()
returns Infinity
and expiryDate()
returns a Date
object for "Tue, 19 Jan 2038 03:14:07 GMT" (latest date that can be expressed by a 32-bit time_t
; the common limit for most user-agents).
.TTL([now=Date.now()])
Computes the TTL relative to now
(milliseconds). The same precedence rules as for expiryTime
/expiryDate
apply.
Infinity
is returned for cookies without an explicit expiry and 0
is returned if the cookie is expired. Otherwise a time-to-live in milliseconds is returned.
.canonicalizedDomain()
.cdomain()
Returns the canonicalized .domain
field. This is lower-cased and punycode (RFC 3490) encoded if the domain has any non-ASCII characters.
.toJSON()
For convenience in using JSON.serialize(cookie)
. Returns a plain-old Object
that can be JSON-serialized.
Any Date
properties (such as .expires
, .creation
, and .lastAccessed
) are exported in ISO format (.toISOString()
).
NOTE: Custom Cookie
properties are discarded. In tough-cookie 1.x, since there was no .toJSON
method explicitly defined, all enumerable properties were captured. If you want a property to be serialized, add the property name to the Cookie.serializableProperties
Array.
Cookie.fromJSON(strOrObj)
Does the reverse of cookie.toJSON()
. If passed a string, will JSON.parse()
that first.
Any Date
properties (such as .expires
, .creation
, and .lastAccessed
) are parsed via Date.parse
, not tough-cookie's parseDate
, since ISO timestamps are being handled at this layer.
Returns null
upon a JSON parsing error.
.clone()
Does a deep clone of this cookie, implemented exactly as Cookie.fromJSON(cookie.toJSON())
.
.validate()
Status: IN PROGRESS. Works for a few things, but is by no means comprehensive.
Validates cookie attributes for semantic correctness. Useful for "lint" checking any Set-Cookie headers you generate. For now, it returns a boolean, but eventually could return a reason string. Future-proof with this construct:
if (cookie.validate() === true) {
} else {
}
CookieJar
Exported via tough.CookieJar
.
CookieJar([store][, options])
Simply use new CookieJar()
. If a custom store is not passed to the constructor, a MemoryCookieStore
is created and used.
The options
object can be omitted and can have the following properties:
- rejectPublicSuffixes - boolean - default
true
- reject cookies with domains like "com" and "co.uk" - looseMode - boolean - default
false
- accept malformed cookies like bar
and =bar
, which have an implied empty name. - prefixSecurity - string - default
silent
- set to 'unsafe-disabled'
, 'silent'
, or 'strict'
. See Cookie Prefixes below. - allowSpecialUseDomain - boolean - default
true
- accepts special-use domain suffixes, such as local
. Useful for testing purposes.
This is not in the standard, but is used sometimes on the web and is accepted by most browsers.
.setCookie(cookieOrString, currentUrl[, options][, callback(err, cookie)])
Attempt to set the cookie in the cookie jar. The cookie has updated .creation
, .lastAccessed
and .hostOnly
properties. And returns a promise if a callback is not provided.
The options
object can be omitted and can have the following properties:
- http - boolean - default
true
- indicates if this is an HTTP or non-HTTP API. Affects HttpOnly
cookies. - secure - boolean - autodetect from URL - indicates if this is a "Secure" API. If the currentUrl starts with
https:
or wss:
this defaults to true
, otherwise false
. - now - Date - default
new Date()
- what to use for the creation or access time of cookies. - ignoreError - boolean - default
false
- silently ignore things like parse errors and invalid domains. Store
errors aren't ignored by this option. - sameSiteContext - string - default unset - set to
'none'
, 'lax'
, or 'strict'
See SameSite Cookies below.
As per the RFC, the .hostOnly
property is set if there was no "Domain=" parameter in the cookie string (or .domain
was null on the Cookie object). The .domain
property is set to the fully-qualified hostname of currentUrl
in this case. Matching this cookie requires an exact hostname match (not a domainMatch
as per usual).
.setCookieSync(cookieOrString, currentUrl[, options])
Synchronous version of setCookie
; only works with synchronous stores (that is, the default MemoryCookieStore
).
.getCookies(currentUrl[, options][, callback(err, cookies)])
Retrieve the list of cookies that can be sent in a Cookie header for the current URL. Returns a promise if a callback is not provided.
Returns an array of Cookie
objects, sorted by default using cookieCompare
.
If an error is encountered it's passed as err
to the callback, otherwise an array of Cookie
objects is passed. The array is sorted with cookieCompare()
unless the {sort:false}
option is given.
The options
object can be omitted and can have the following properties:
- http - boolean - default
true
- indicates if this is an HTTP or non-HTTP API. Affects HttpOnly
cookies. - secure - boolean - autodetect from URL - indicates if this is a "Secure" API. If the currentUrl starts with
https:
or wss:
then this is defaulted to true
, otherwise false
. - now - Date - default
new Date()
- what to use for the creation or access time of cookies - expire - boolean - default
true
- perform expiry-time checking of cookies and asynchronously remove expired cookies from the store. Using false
returns expired cookies and does not remove them from the store (which is potentially useful for replaying Set-Cookie headers). - allPaths - boolean - default
false
- if true
, do not scope cookies by path. The default uses RFC-compliant path scoping. Note: may not be supported by the underlying store (the default MemoryCookieStore
supports it). - sameSiteContext - string - default unset - Set this to
'none'
, 'lax'
, or 'strict'
to enforce SameSite cookies upon retrieval. See SameSite Cookies below. - sort - boolean - whether to sort the list of cookies.
The .lastAccessed
property of the returned cookies will have been updated.
.getCookiesSync(currentUrl, [{options}])
Synchronous version of getCookies
; only works with synchronous stores (for example, the default MemoryCookieStore
).
.getCookieString(...)
Accepts the same options as .getCookies()
but returns a string suitable for a Cookie header rather than an Array.
.getCookieStringSync(...)
Synchronous version of getCookieString
; only works with synchronous stores (for example, the default MemoryCookieStore
).
.getSetCookieStrings(...)
Returns an array of strings suitable for Set-Cookie headers. Accepts the same options as .getCookies()
. Simply maps the cookie array via .toString()
.
.getSetCookieStringsSync(...)
Synchronous version of getSetCookieStrings
; only works with synchronous stores (for example, the default MemoryCookieStore
).
.serialize([callback(err, serializedObject)])
Returns a promise if a callback is not provided.
Serialize the Jar if the underlying store supports .getAllCookies
.
NOTE: Custom Cookie
properties are discarded. If you want a property to be serialized, add the property name to the Cookie.serializableProperties
Array.
See Serialization Format.
.serializeSync()
Synchronous version of serialize
; only works with synchronous stores (for example, the default MemoryCookieStore
).
.toJSON()
Alias of .serializeSync()
for the convenience of JSON.stringify(cookiejar)
.
CookieJar.deserialize(serialized[, store][, callback(err, object)])
A new Jar is created and the serialized Cookies are added to the underlying store. Each Cookie
is added via store.putCookie
in the order in which they appear in the serialization. A promise is returned if a callback is not provided.
The store
argument is optional, but should be an instance of Store
. By default, a new instance of MemoryCookieStore
is created.
As a convenience, if serialized
is a string, it is passed through JSON.parse
first.
CookieJar.deserializeSync(serialized[, store])
Sync version of .deserialize
; only works with synchronous stores (for example, the default MemoryCookieStore
).
CookieJar.fromJSON(string)
Alias of .deserializeSync
to provide consistency with Cookie.fromJSON()
.
.clone([store][, callback(err, cloned))
Produces a deep clone of this jar. Modifications to the original do not affect the clone, and vice versa. Returns a promise if a callback is not provided.
The store
argument is optional, but should be an instance of Store
. By default, a new instance of MemoryCookieStore
is created. Transferring between store types is supported so long as the source implements .getAllCookies()
and the destination implements .putCookie()
.
.cloneSync([store])
Synchronous version of .clone
, returning a new CookieJar
instance.
The store
argument is optional, but must be a synchronous Store
instance if specified. If not passed, a new instance of MemoryCookieStore
is used.
The source and destination must both be synchronous Store
s. If one or both stores are asynchronous, use .clone
instead. Recall that MemoryCookieStore
supports both synchronous and asynchronous API calls.
.removeAllCookies([callback(err)])
Removes all cookies from the jar. Returns a promise if a callback is not provided.
This is a new backwards-compatible feature of tough-cookie
version 2.5, so not all Stores will implement it efficiently. For Stores that do not implement removeAllCookies
, the fallback is to call removeCookie
after getAllCookies
. If getAllCookies
fails or isn't implemented in the Store, that error is returned. If one or more of the removeCookie
calls fail, only the first error is returned.
.removeAllCookiesSync()
Sync version of .removeAllCookies()
; only works with synchronous stores (for example, the default MemoryCookieStore
).
Store
Base class for CookieJar stores. Available as tough.Store
.
Store API
The storage model for each CookieJar
instance can be replaced with a custom implementation. The default is MemoryCookieStore
which can be found in lib/memstore.js
. The API uses continuation-passing-style to allow for asynchronous stores.
Stores should inherit from the base Store
class, which is available as a top-level export.
Stores are asynchronous by default, but if store.synchronous
is set to true
, then the *Sync
methods of the containing CookieJar
can be used.
All domain
parameters are normalized before calling.
The Cookie store must have all of the following methods. Note that asynchronous implementations must support callback parameters.
store.findCookie(domain, path, key, callback(err, cookie))
Retrieve a cookie with the given domain, path, and key (name). The RFC maintains that exactly one of these cookies should exist in a store. If the store is using versioning, this means that the latest or newest such cookie should be returned.
Callback takes an error and the resulting Cookie
object. If no cookie is found then null
MUST be passed instead (that is, not an error).
store.findCookies(domain, path, allowSpecialUseDomain, callback(err, cookies))
Locates cookies matching the given domain and path. This is most often called in the context of cookiejar.getCookies()
.
If no cookies are found, the callback MUST be passed an empty array.
The resulting list is checked for applicability to the current request according to the RFC (domain-match, path-match, http-only-flag, secure-flag, expiry, and so on), so it's OK to use an optimistic search algorithm when implementing this method. However, the search algorithm used SHOULD try to find cookies that domainMatch()
the domain and pathMatch()
the path in order to limit the amount of checking that needs to be done.
As of version 0.9.12, the allPaths
option to cookiejar.getCookies()
above causes the path here to be null
. If the path is null
, path-matching MUST NOT be performed (that is, domain-matching only).
store.putCookie(cookie, callback(err))
Adds a new cookie to the store. The implementation SHOULD replace any existing cookie with the same .domain
, .path
, and .key
properties. Depending on the nature of the implementation, it's possible that between the call to fetchCookie
and putCookie
that a duplicate putCookie
can occur.
The cookie
object MUST NOT be modified; as the caller has already updated the .creation
and .lastAccessed
properties.
Pass an error if the cookie cannot be stored.
store.updateCookie(oldCookie, newCookie, callback(err))
Update an existing cookie. The implementation MUST update the .value
for a cookie with the same domain
, .path
, and .key
. The implementation SHOULD check that the old value in the store is equivalent to oldCookie
- how the conflict is resolved is up to the store.
The .lastAccessed
property is always different between the two objects (to the precision possible via JavaScript's clock). Both .creation
and .creationIndex
are guaranteed to be the same. Stores MAY ignore or defer the .lastAccessed
change at the cost of affecting how cookies are selected for automatic deletion (for example, least-recently-used, which is up to the store to implement).
Stores may wish to optimize changing the .value
of the cookie in the store versus storing a new cookie. If the implementation doesn't define this method, a stub that calls putCookie
is added to the store object.
The newCookie
and oldCookie
objects MUST NOT be modified.
Pass an error if the newCookie cannot be stored.
store.removeCookie(domain, path, key, callback(err))
Remove a cookie from the store (see notes on findCookie
about the uniqueness constraint).
The implementation MUST NOT pass an error if the cookie doesn't exist, and only pass an error due to the failure to remove an existing cookie.
store.removeCookies(domain, path, callback(err))
Removes matching cookies from the store. The path
parameter is optional and if missing, means all paths in a domain should be removed.
Pass an error ONLY if removing any existing cookies failed.
store.removeAllCookies(callback(err))
Optional. Removes all cookies from the store.
Pass an error if one or more cookies can't be removed.
store.getAllCookies(callback(err, cookies))
Optional. Produces an Array
of all cookies during jar.serialize()
. The items in the array can be true Cookie
objects or generic Object
s with the Serialization Format data structure.
Cookies SHOULD be returned in creation order to preserve sorting via compareCookie()
. For reference, MemoryCookieStore
sorts by .creationIndex
since it uses true Cookie
objects internally. If you don't return the cookies in creation order, they'll still be sorted by creation time, but this only has a precision of 1-ms. See cookieCompare
for more detail.
Pass an error if retrieval fails.
Note: Not all Stores can implement this due to technical limitations, so it is optional.
MemoryCookieStore
Inherits from Store
.
A just-in-memory CookieJar synchronous store implementation, used by default. Despite being a synchronous implementation, it's usable with both the synchronous and asynchronous forms of the CookieJar
API. Supports serialization, getAllCookies
, and removeAllCookies
.
These are some Store implementations authored and maintained by the community. They aren't official and we don't vouch for them but you may be interested to have a look:
Serialization Format
NOTE: If you want to have custom Cookie
properties serialized, add the property name to Cookie.serializableProperties
.
{
version: 'tough-cookie@1.x.y',
storeType: 'MemoryCookieStore',
rejectPublicSuffixes: true,
cookies: [
{
key: 'string',
value: 'string',
}
]
}
RFC 6265bis
Support for RFC 6265bis revision 02 is being developed. Since this is a bit of an omnibus revision to the RFC 6252, support is broken up into the functional areas.
Leave Secure Cookies Alone
Not yet supported.
This change makes it so that if a cookie is sent from the server to the client with a Secure
attribute, the channel must also be secure or the cookie is ignored.
SameSite Cookies
Supported.
This change makes it possible for servers, and supporting clients, to mitigate certain types of CSRF attacks by disallowing SameSite
cookies from being sent cross-origin.
On the Cookie object itself, you can get or set the .sameSite
attribute, which is serialized into the SameSite=
cookie attribute. When unset or undefined
, no SameSite=
attribute is serialized. The valid values of this attribute are 'none'
, 'lax'
, or 'strict'
. Other values are serialized as-is.
When parsing cookies with a SameSite
cookie attribute, values other than 'lax'
or 'strict'
are parsed as 'none'
. For example, SomeCookie=SomeValue; SameSite=garbage
parses so that cookie.sameSite === 'none'
.
In order to support SameSite cookies, you must provide a sameSiteContext
option to both setCookie
and getCookies
. Valid values for this option are just like for the Cookie object, but have particular meanings:
'strict'
mode - If the request is on the same "site for cookies" (see the RFC draft for more information), pass this option to add a layer of defense against CSRF.'lax'
mode - If the request is from another site, but is directly because of navigation by the user, such as, <link type=prefetch>
or <a href="...">
, pass sameSiteContext: 'lax'
.'none'
- Otherwise, pass sameSiteContext: 'none'
(this indicates a cross-origin request).- unset/
undefined
- SameSite is not be enforced! This can be a valid use-case for when CSRF isn't in the threat model of the system being built.
It is highly recommended that you read RFC 6265bis for fine details on SameSite cookies. In particular Section 8.8 discusses security considerations and defense in depth.
Cookie Prefixes
Supported.
Cookie prefixes are a way to indicate that a given cookie was set with a set of attributes simply by inspecting the first few characters of the cookie's name.
Cookie prefixes are defined in Section 4.1.3 of 6265bis.
Two prefixes are defined:
"__Secure-" Prefix
: If a cookie's name begins with a case-sensitive match for the string "__Secure-", then the cookie was set with a "Secure" attribute."__Host-" Prefix
: If a cookie's name begins with a case-sensitive match for the string "__Host-", then the cookie was set with a "Secure" attribute, a "Path" attribute with a value of "/", and no "Domain" attribute.
If prefixSecurity
is enabled for CookieJar
, then cookies that match the prefixes defined above but do not obey the attribute restrictions are not added.
You can define this functionality by passing in the prefixSecurity
option to CookieJar
. It can be one of 3 values:
silent
: Enable cookie prefix checking but silently fail to add the cookie if conditions are not met. Default.strict
: Enable cookie prefix checking and error out if conditions are not met.unsafe-disabled
: Disable cookie prefix checking.
Note that if ignoreError
is passed in as true
then the error is silent regardless of the prefixSecurity
option (assuming it's enabled).
Copyright and License
BSD-3-Clause:
Copyright (c) 2015, Salesforce.com, Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. Neither the name of Salesforce.com nor the names of its contributors may
be used to endorse or promote products derived from this software without
specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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