This page provides a complete reference of all the methods
and options supported by the CryptContext class
and helper utilities.
The CryptContext Class
-
class
passlib.context.CryptContext(schemes=None, **kwds)
Helper for hashing passwords using different algorithms.
At its base, this is a proxy object that makes it easy to use
multiple PasswordHash objects at the same time.
Instances of this class can be created by calling the constructor
with the appropriate keywords, or by using one of the alternate
constructors, which can load directly from a string or a local file.
Since this class has so many options and methods, they have been broken
out into subsections:
Constructor Keywords
The CryptContext class accepts the following keywords,
all of which are optional.
The keywords are divided into two categories: context options, which affect
the CryptContext itself; and algorithm options, which place defaults
and limits on the algorithms used by the CryptContext.
Context Options
Options which directly affect the behavior of the CryptContext instance:
schemesList of algorithms which the instance should support.
The most important option in the constructor,
This option controls what hashes can be used
by the hash() method,
which hashes will be recognized by verify()
and identify(), and other effects
throughout the instance.
It should be a sequence of names,
drawn from the hashes in passlib.hash.
Listing an unknown name will cause a ValueError.
You can use the schemes() method
to get a list of the currently configured algorithms.
As an example, the following creates a CryptContext instance
which supports the sha256_crypt and
des_crypt schemes:
>>> from passlib.context import CryptContext
>>> myctx = CryptContext(schemes=["sha256_crypt", "des_crypt"])
>>> myctx.schemes()
("sha256_crypt", "des_crypt")
Note
The order of the schemes is sometimes important,
as identify() will run
through the schemes from first to last until an algorithm
“claims” the hash. So plaintext algorithms and
the like should be listed at the end.
defaultSpecifies the name of the default scheme.
This option controls which of the configured
schemes will be used as the default when creating
new hashes. This parameter is optional; if omitted,
the first non-deprecated algorithm in schemes will be used.
You can use the default_scheme() method
to retrieve the name of the current default scheme.
As an example, the following demonstrates the effect
of this parameter on the hash()
method:
>>> from passlib.context import CryptContext
>>> myctx = CryptContext(schemes=["sha256_crypt", "md5_crypt"])
>>> # hash() uses the first scheme
>>> myctx.default_scheme()
'sha256_crypt'
>>> myctx.hash("password")
'$5$rounds=80000$R5ZIZRTNPgbdcWq5$fT/Oeqq/apMa/0fbx8YheYWS6Z3XLTxCzEtutsk2cJ1'
>>> # but setting default causes the second scheme to be used.
>>> myctx.update(default="md5_crypt")
>>> myctx.default_scheme()
'md5_crypt'
>>> myctx.hash("password")
'$1$Rr0C.KI8$Kvciy8pqfL9BQ2CJzEzfZ/'
deprecatedList of algorithms which should be considered “deprecated”.
This has the same format as schemes, and should be
a subset of those algorithms. The main purpose of this
method is to flag schemes which need to be rehashed
when the user next logs in. This has no effect
on the Primary Methods; but if the special Hash Migration
methods are passed a hash belonging to a deprecated scheme,
they will flag it as needed to be rehashed using
the default scheme.
This may also contain a single special value,
["auto"], which will configure the CryptContext instance
to deprecate all supported schemes except for the default scheme.
New in version 1.6: Added support for the ["auto"] value.
truncate_error
By default, some algorithms will truncate large passwords
(e.g. bcrypt truncates ones larger than 72 bytes).
Such hashes accept a truncate_error=True option to make them
raise a PasswordTruncateError instead.
This can also be set at the CryptContext level,
and will passed to all hashes that support it.
min_verify_time
If specified, unsuccessful verify()
calls will be penalized, and take at least this may
seconds before the method returns. May be an integer
or fractional number of seconds.
Deprecated since version 1.6: This option has not proved very useful, is ignored by 1.7,
and will be removed in version 1.8.
Changed in version 1.7: Per deprecation roadmap above, this option is now ignored.
harden_verify
Companion to min_verify_time, currently ignored.
Deprecated since version 1.7.1: This option is ignored by 1.7.1, and will be removed in 1.8
along with min_verify_time.
Algorithm Options
All of the other options that can be passed to a CryptContext
constructor affect individual hash algorithms.
All of the following keys have the form scheme__key,
where scheme is the name of one of the algorithms listed
in schemes, and option one of the parameters below:
scheme__rounds
Set the number of rounds required for this scheme
when generating new hashes (using hash()).
Existing hashes which have a different number of rounds will be marked
as deprecated.
This essentially sets default_rounds, min_rounds, and max_rounds all at once.
If any of those options are also specified, they will override the value specified
by rounds.
New in version 1.7: Previous releases of Passlib treated this as an alias for default_rounds.
scheme__default_rounds
Sets the default number of rounds to use with this scheme
when generating new hashes (using hash()).
If not set, this will fall back to the an algorithm-specific
default_rounds.
For hashes which do not support a rounds parameter, this option is ignored.
As an example:
>>> from passlib.context import CryptContext
>>> # no explicit default_rounds set, so hash() uses sha256_crypt's default (80000)
>>> myctx = CryptContext(["sha256_crypt"])
>>> myctx.hash("fooey")
'$5$rounds=80000$60Y7mpmAhUv6RDvj$AdseAOq6bKUZRDRTr/2QK1t38qm3P6sYeXhXKnBAmg0'
^^^^^
>>> # but if a default is specified, it will be used instead.
>>> myctx = CryptContext(["sha256_crypt"], sha256_crypt__default_rounds=77123)
>>> myctx.hash("fooey")
'$5$rounds=77123$60Y7mpmAhUv6RDvj$AdseAOq6bKUZRDRTr/2QK1t38qm3P6sYeXhXKnBAmg0'
^^^^^
scheme__vary_rounds
Deprecated since version 1.7: This option has been deprecated as of Passlib 1.7, and will be removed in Passlib 2.0.
The (very minimal) security benefit it provides was judged to not be worth code complexity
it requires.
Instead of using a fixed rounds value (such as specified by
default_rounds, above); this option will cause each call
to hash() to vary the default rounds value
by some amount.
This can be an integer value, in which case each call will use a rounds
value within the range default_rounds +/- vary_rounds. It may
also be a floating point value within the range 0.0 .. 1.0,
in which case the range will be calculated as a proportion of the
current default rounds (default_rounds +/- default_rounds*vary_rounds).
A typical setting is 0.1 to 0.2.
As an example of how this parameter operates:
>>> # without vary_rounds set, hash() uses the same amount each time:
>>> from passlib.context import CryptContext
>>> myctx = CryptContext(schemes=["sha256_crypt"],
... sha256_crypt__default_rounds=80000)
>>> myctx.hash("fooey")
'$5$rounds=80000$60Y7mpmAhUv6RDvj$AdseAOq6bKUZRDRTr/2QK1t38qm3P6sYeXhXKnBAmg0'
>>> myctx.hash("fooey")
'$5$rounds=80000$60Y7mpmAhUv6RDvj$AdseAOq6bKUZRDRTr/2QK1t38qm3P6sYeXhXKnBAmg0'
^^^^^
>>> # but if vary_rounds is set, each one will be randomized
>>> # (in this case, within the range 72000 .. 88000)
>>> myctx = CryptContext(schemes=["sha256_crypt"],
... sha256_crypt__default_rounds=80000,
... sha256_crypt__vary_rounds=0.1)
>>> myctx.hash("fooey")
'$5$rounds=83966$bMpgQxN2hXo2kVr4$jL4Q3ov41UPgSbO7jYL0PdtsOg5koo4mCa.UEF3zan.'
>>> myctx.hash("fooey")
'$5$rounds=72109$43BBHC/hYPHzL69c$VYvVIdKn3Zdnvu0oJHVlo6rr0WjiMTGmlrZrrH.GxnA'
^^^^^
Note
This is not a needed security measure, but it lets some of the less-significant
digits of the rounds value act as extra salt bits; and helps foil
any attacks targeted at a specific number of rounds of a hash.
scheme__min_rounds,
scheme__max_rounds
These options place a limit on the number of rounds allowed for a particular
scheme.
For one, they limit what values are allowed for default_rounds,
and clip the effective range of the vary_rounds parameter.
More importantly though, they proscribe a minimum strength for the hash,
and any hashes which don’t have sufficient rounds will be flagged as
needing rehashing by the Hash Migration methods.
Note
These are configurable per-context limits.
A warning will be issued if they exceed any hard limits
set by the algorithm itself.
scheme__other-option
Finally, any other options are assumed to correspond to one of the
that algorithm’s hash() settings,
such as setting a salt_size.
Global Algorithm Options
all__option
The special scheme all permits you to set an option, and have
it act as a global default for all the algorithms in the context.
For instance, all__vary_rounds=0.1 would set the vary_rounds
option for all the schemes where it was not overridden with an
explicit scheme__vary_rounds option.
Deprecated since version 1.7: This special scheme is deprecated as of Passlib 1.7, and will be removed in Passlib 2.0.
It’s only legitimate use was for vary_rounds, which is also being removed in Passlib 2.0.
User Categories
category__context__option,
category__scheme__option
Passing keys with this format to the CryptContext constructor
allows you to specify conditional context and algorithm options,
controlled by the category parameter supported by most CryptContext
methods.
These options are conditional because they only take effect if
the category prefix of the option matches the value of the category
parameter of the CryptContext method being invoked. In that case,
they override any options specified without a category
prefix (e.g. admin__sha256_crypt__min_rounds would override
sha256_crypt__min_rounds).
The category prefix and the value passed into the category parameter
can be any string the application wishes to use, the only constraint
is that None indicates the default category.
Motivation:
Policy limits such as default rounds values and deprecated schemes
generally have to be set globally. However, it’s frequently desirable
to specify stronger options for certain accounts (such as admin accounts),
choosing to sacrifice longer hashing time for a more secure password.
The user categories system allows for this.
For example, a CryptContext could be set up as follows:
>>> # A context object can be set up as follows:
>>> from passlib.context import CryptContext
>>> myctx = CryptContext(schemes=["sha256_crypt"],
... sha256_crypt__default_rounds=77000,
... staff__sha256_crypt__default_rounds=88000)
>>> # In this case, calling hash() with ``category=None`` would result
>>> # in a hash that used 77000 sha256-crypt rounds:
>>> myctx.hash("password", category=None)
'$5$rounds=77000$sj3XI0AbKlEydAKt$BhFvyh4.IoxaUeNlW6rvQ.O0w8BtgLQMYorkCOMzf84'
^^^^^
>>> # But if the application passed in ``category="staff"`` when an administrative
>>> # account set their password, 88000 rounds would be used:
>>> myctx.hash("password", category="staff")
'$5$rounds=88000$w7XIdKfTI9.YLwmA$MIzGvs6NU1QOQuuDHhICLmDsdW/t94Bbdfxdh/6NJl7'
^^^^^
Primary Methods
The main interface to the CryptContext object deliberately mirrors
the PasswordHash interface, since its central
purpose is to act as a container for multiple password hashes.
Most applications will only need to make use two methods in a CryptContext
instance:
-
CryptContext.hash(secret, scheme=None, category=None, **kwds)
run secret through selected algorithm, returning resulting hash.
| Parameters: |
|
|---|
| Returns: | The secret as encoded by the specified algorithm and options.
The return value will always be a str.
|
|---|
| Raises: | TypeError, ValueError –
- If any of the arguments have an invalid type or value.
This includes any keywords passed to the underlying hash’s
PasswordHash.hash() method.
|
|---|
-
CryptContext.encrypt(*args, **kwds)
Legacy alias for hash().
Deprecated since version 1.7: This method was renamed to hash() in version 1.7.
This alias will be removed in version 2.0, and should only
be used for compatibility with Passlib 1.3 - 1.6.
-
CryptContext.verify(secret, hash, scheme=None, category=None, **kwds)
verify secret against an existing hash.
If no scheme is specified, this will attempt to identify
the scheme based on the contents of the provided hash
(limited to the schemes configured for this context).
It will then check whether the password verifies against the hash.
| Parameters: |
- secret (unicode or bytes) – the secret to verify
- hash (unicode or bytes) –
hash string to compare to
if None is passed in, this will be treated as “never verifying”
- scheme (str) –
Optionally force context to use specific scheme.
This is usually not needed, as most hashes can be unambiguously
identified. Scheme must be one of the ones configured
for this context
(see the schemes option).
Deprecated since version 1.7: Support for this keyword is deprecated, and will be removed in Passlib 2.0.
- category (str or None) – Optional user category string.
This is mainly used when generating new hashes, it has little
effect when verifying; this keyword is mainly provided for symmetry.
- **kwds – All additional keywords are passed to the appropriate handler,
and should match its
context_kwds.
|
|---|
| Returns: | True if the password matched the hash, else False.
|
|---|
| Raises: |
- ValueError –
- if the hash did not match any of the configured
schemes().
- if any of the arguments have an invalid value (this includes
any keywords passed to the underlying hash’s
PasswordHash.verify() method).
- TypeError –
- if any of the arguments have an invalid type (this includes
any keywords passed to the underlying hash’s
PasswordHash.verify() method).
|
|---|
-
CryptContext.identify(hash, category=None, resolve=False, required=False, unconfigured=False)
Attempt to identify which algorithm the hash belongs to.
Note that this will only consider the algorithms
currently configured for this context
(see the schemes option).
All registered algorithms will be checked, from first to last,
and whichever one positively identifies the hash first will be returned.
| Parameters: |
- hash (unicode or bytes) – The hash string to test.
- category (str or None) – Optional user category.
Ignored by this function, this parameter
is provided for symmetry with the other methods.
- resolve (bool) – If
True, returns the hash handler itself,
instead of the name of the hash.
- required (bool) – If
True, this will raise a ValueError if the hash
cannot be identified, instead of returning None.
|
|---|
| Returns: | The handler which first identifies the hash,
or None if none of the algorithms identify the hash.
|
|---|
-
CryptContext.dummy_verify(elapsed=0)
Helper that applications can call when user wasn’t found,
in order to simulate time it would take to hash a password.
Runs verify() against a dummy hash, to simulate verification
of a real account password.
| Parameters: | elapsed –
Deprecated since version 1.7.1: this option is ignored, and will be removed in passlib 1.8.
|
|---|
“crypt”-style methods
Additionally, the main interface offers wrappers for the two Unix “crypt”
style methods provided by all the PasswordHash objects:
-
CryptContext.genhash(secret, config, scheme=None, category=None, **kwds)
Generate hash for the specified secret using another hash.
Deprecated since version 1.7: This method will be removed in version 2.0, and should only
be used for compatibility with Passlib 1.3 - 1.6.
-
CryptContext.genconfig(scheme=None, category=None, **settings)
Generate a config string for specified scheme.
Deprecated since version 1.7: This method will be removed in version 2.0, and should only
be used for compatibility with Passlib 1.3 - 1.6.
Hash Migration
Applications which want to detect and regenerate deprecated
hashes will want to use one of the following methods:
-
CryptContext.verify_and_update(secret, hash, scheme=None, category=None, **kwds)
verify password and re-hash the password if needed, all in a single call.
This is a convenience method which takes care of all the following:
first it verifies the password (verify()), if this is successfull
it checks if the hash needs updating (needs_update()), and if so,
re-hashes the password (hash()), returning the replacement hash.
This series of steps is a very common task for applications
which wish to update deprecated hashes, and this call takes
care of all 3 steps efficiently.
| Parameters: |
- secret (unicode or bytes) – the secret to verify
- hash –
hash string to compare to.
if None is passed in, this will be treated as “never verifying”
- scheme (str) –
Optionally force context to use specific scheme.
This is usually not needed, as most hashes can be unambiguously
identified. Scheme must be one of the ones configured
for this context
(see the schemes option).
Deprecated since version 1.7: Support for this keyword is deprecated, and will be removed in Passlib 2.0.
- category (str or None) – Optional user category.
If specified, this will cause any category-specific defaults to
be used if the password has to be re-hashed.
- **kwds – all additional keywords are passed to the appropriate handler,
and should match that hash’s
PasswordHash.context_kwds.
|
|---|
| Returns: | This function returns a tuple containing two elements:
(verified, replacement_hash). The first is a boolean
flag indicating whether the password verified,
and the second an optional replacement hash.
The tuple will always match one of the following 3 cases:
(False, None) indicates the secret failed to verify.(True, None) indicates the secret verified correctly,
and the hash does not need updating.(True, str) indicates the secret verified correctly,
but the current hash needs to be updated. The str
will be the freshly generated hash, to replace the old one.
|
|---|
| Raises: | TypeError, ValueError – For the same reasons as verify().
|
|---|
-
CryptContext.needs_update(hash, scheme=None, category=None, secret=None)
Check if hash needs to be replaced for some reason,
in which case the secret should be re-hashed.
This function is the core of CryptContext’s support for hash migration:
This function takes in a hash string, and checks the scheme,
number of rounds, and other properties against the current policy.
It returns True if the hash is using a deprecated scheme,
or is otherwise outside of the bounds specified by the policy
(e.g. the number of rounds is lower than min_rounds
configuration for that algorithm).
If so, the password should be re-hashed using hash()
Otherwise, it will return False.
| Parameters: |
- hash (unicode or bytes) – The hash string to examine.
- scheme (str or None) –
Optional scheme to use. Scheme must be one of the ones
configured for this context (see the
schemes option).
If no scheme is specified, it will be identified
based on the value of hash.
Deprecated since version 1.7: Support for this keyword is deprecated, and will be removed in Passlib 2.0.
- category (str or None) – Optional user category.
If specified, this will cause any category-specific defaults to
be used when determining if the hash needs to be updated
(e.g. is below the minimum rounds).
- secret (unicode, bytes, or None) –
Optional secret associated with the provided hash.
This is not required, or even currently used for anything...
it’s for forward-compatibility with any future
update checks that might need this information.
If provided, Passlib assumes the secret has already been
verified successfully against the hash.
|
|---|
| Returns: | True if hash should be replaced, otherwise False.
|
|---|
| Raises: | ValueError – If the hash did not match any of the configured schemes().
|
|---|
-
CryptContext.hash_needs_update(hash, scheme=None, category=None)
Legacy alias for needs_update().
Deprecated since version 1.6: This method was renamed to needs_update() in version 1.6.
This alias will be removed in version 2.0, and should only
be used for compatibility with Passlib 1.3 - 1.5.
Disabled Hash Managment
It’s frequently useful to disable a user’s ability to login by
replacing their password hash with a standin that’s guaranteed
to never verify, against any password. CryptContext offers
some convenience methods for this through the following API.
-
CryptContext.disable(hash=None)
return a string to disable logins for user,
usually by returning a non-verifying string such as "!".
| Parameters: | hash – Callers can optionally provide the account’s existing hash.
Some disabled handlers (such as unix_disabled)
will encode this into the returned value,
so that it can be recovered via enable(). |
|---|
| Raises: | RuntimeError – if this function is called w/o a disabled hasher
(such as unix_disabled) included
in the list of schemes. |
|---|
| Returns: | hash string which will be recognized as valid by the context,
but is guaranteed to not validate against any password. |
|---|
-
CryptContext.enable(hash)
inverse of disable() –
attempts to recover original hash which was converted
by a disable() call into a disabled hash –
thus restoring the user’s original password.
| Raises: | ValueError – if original hash not present, or if the disabled handler doesn’t
support encoding the original hash (e.g. django_disabled) |
|---|
| Returns: | the original hash. |
|---|
-
CryptContext.is_enabled(hash)
test if hash represents a usuable password –
i.e. does not represent an unusuable password such as "!",
which is recognized by the unix_disabled hash.
| Raises: | ValueError – if the hash is not recognized
(typically solved by adding unix_disabled to the list of schemes). |
|---|
Alternate Constructors
In addition to the main class constructor, which accepts a configuration
as a set of keywords, there are the following alternate constructors:
-
classmethod
CryptContext.from_string(source, section='passlib', encoding='utf-8')
create new CryptContext instance from an INI-formatted string.
| Parameters: |
- source (unicode or bytes) – string containing INI-formatted content.
- section (str) – option name of section to read from, defaults to
"passlib".
- encoding (str) – optional encoding used when source is bytes, defaults to
"utf-8".
|
|---|
| Returns: | new CryptContext instance, configured based on the
parameters in the source string.
|
|---|
Usage example:
>>> from passlib.context import CryptContext
>>> context = CryptContext.from_string('''
... [passlib]
... schemes = sha256_crypt, des_crypt
... sha256_crypt__default_rounds = 30000
... ''')
-
classmethod
CryptContext.from_path(path, section='passlib', encoding='utf-8')
create new CryptContext instance from an INI-formatted file.
this functions exactly the same as from_string(),
except that it loads from a local file.
| Parameters: |
- path (str) – path to local file containing INI-formatted config.
- section (str) – option name of section to read from, defaults to
"passlib".
- encoding (str) – encoding used to load file, defaults to
"utf-8".
|
|---|
| Returns: | new CryptContext instance, configured based on the parameters
stored in the file path.
|
|---|
-
CryptContext.copy(**kwds)
Return copy of existing CryptContext instance.
This function returns a new CryptContext instance whose configuration
is exactly the same as the original, with the exception that any keywords
passed in will take precedence over the original settings.
As an example:
>>> from passlib.context import CryptContext
>>> # given an existing context...
>>> ctx1 = CryptContext(["sha256_crypt", "md5_crypt"])
>>> # copy can be used to make a clone, and update
>>> # some of the settings at the same time...
>>> ctx2 = custom_app_context.copy(default="md5_crypt")
>>> # and the original will be unaffected by the change
>>> ctx1.default_scheme()
"sha256_crypt"
>>> ctx2.default_scheme()
"md5_crypt"
New in version 1.6: This method was previously named replace(). That alias
has been deprecated, and will be removed in Passlib 1.8.
Changing the Configuration
CryptContext objects can have their configuration replaced or updated
on the fly, and from a variety of sources (keywords, strings, files).
This is done through three methods:
-
CryptContext.update(**kwds)
Helper for quickly changing configuration.
This acts much like the dict.update() method:
it updates the context’s configuration,
replacing the original value(s) for the specified keys,
and preserving the rest.
It accepts any keyword
accepted by the CryptContext constructor.
-
CryptContext.load(source, update=False, section='passlib', encoding='utf-8')
Load new configuration into CryptContext, replacing existing config.
| Parameters: |
|
|---|
| Raises: |
- TypeError –
- If the source cannot be identified.
- If an unknown / malformed keyword is encountered.
- ValueError – If an invalid keyword value is encountered.
|
|---|
Note
If an error occurs during a load() call, the CryptContext
instance will be restored to the configuration it was in before
the load() call was made; this is to ensure it is
never left in an inconsistent state due to a load error.
-
CryptContext.load_path(path, update=False, section='passlib', encoding='utf-8')
Load new configuration into CryptContext from a local file.
This function is a wrapper for load() which
loads a configuration string from the local file path,
instead of an in-memory source. Its behavior and options
are otherwise identical to load() when provided with
an INI-formatted string.
Examining the Configuration
The CryptContext object also supports basic inspection of its
current configuration:
-
CryptContext.schemes(resolve=False, category=None, unconfigured=False)
return schemes loaded into this CryptContext instance.
| Parameters: | resolve (bool) – if True, will return a tuple of PasswordHash
objects instead of their names. |
|---|
| Returns: | returns tuple of the schemes configured for this context
via the schemes option. |
|---|
New in version 1.6: This was previously available as CryptContext().policy.schemes()
See also
the schemes option for usage example.
-
CryptContext.default_scheme(category=None, resolve=False, unconfigured=False)
return name of scheme that hash() will use by default.
| Parameters: |
- resolve (bool) – if
True, will return a PasswordHash
object instead of the name.
- category (str or None) – Optional user category.
If specified, this will return the catgory-specific default scheme instead.
|
|---|
| Returns: | name of the default scheme.
|
|---|
See also
the default option for usage example.
Changed in version 1.7: This now returns a hasher configured with any CryptContext-specific
options (custom rounds settings, etc). Previously this returned
the base hasher from passlib.hash.
-
CryptContext.handler(scheme=None, category=None, unconfigured=False)
helper to resolve name of scheme -> PasswordHash object used by scheme.
| Parameters: |
- scheme – This should identify the scheme to lookup.
If omitted or set to
None, this will return the handler
for the default scheme.
- category – If a user category is specified, and no scheme is provided,
it will use the default for that category.
Otherwise this parameter is ignored.
- unconfigured – By default, this returns a handler object whose .hash()
and .needs_update() methods will honor the configured
provided by CryptContext. See
unconfigured=True
to get the underlying handler from before any context-specific
configuration was applied.
|
|---|
| Raises: | KeyError – If the scheme does not exist OR is not being used within this context.
|
|---|
| Returns: | PasswordHash object used to implement
the named scheme within this context (this will usually
be one of the objects from passlib.hash)
|
|---|
New in version 1.6: This was previously available as CryptContext().policy.get_handler()
Changed in version 1.7: This now returns a hasher configured with any CryptContext-specific
options (custom rounds settings, etc). Previously this returned
the base hasher from passlib.hash.
-
CryptContext.context_kwds
return set containing union of all contextual keywords
supported by the handlers in this context.
Saving the Configuration
More detailed inspection can be done by exporting the configuration
using one of the serialization methods:
-
CryptContext.to_dict(resolve=False)
Return current configuration as a dictionary.
| Parameters: | resolve (bool) – if True, the schemes key will contain a list of
a PasswordHash objects instead of just
their names. |
|---|
This method dumps the current configuration of the CryptContext
instance. The key/value pairs should be in the format accepted
by the CryptContext class constructor, in fact
CryptContext(**myctx.to_dict()) will create an exact copy of myctx.
As an example:
>>> # you can dump the configuration of any crypt context...
>>> from passlib.apps import ldap_nocrypt_context
>>> ldap_nocrypt_context.to_dict()
{'schemes': ['ldap_salted_sha1',
'ldap_salted_md5',
'ldap_sha1',
'ldap_md5',
'ldap_plaintext']}
New in version 1.6: This was previously available as CryptContext().policy.to_dict()
-
CryptContext.to_string(section='passlib')
serialize to INI format and return as unicode string.
| Parameters: | section – name of INI section to output, defaults to "passlib". |
|---|
| Returns: | CryptContext configuration, serialized to a INI unicode string. |
|---|
This function acts exactly like to_dict(), except that it
serializes all the contents into a single human-readable string,
which can be hand edited, and/or stored in a file. The
output of this method is accepted by from_string(),
from_path(), and load(). As an example:
>>> # you can dump the configuration of any crypt context...
>>> from passlib.apps import ldap_nocrypt_context
>>> print ldap_nocrypt_context.to_string()
[passlib]
schemes = ldap_salted_sha1, ldap_salted_md5, ldap_sha1, ldap_md5, ldap_plaintext
New in version 1.6: This was previously available as CryptContext().policy.to_string()
Configuration Errors
The following errors may be raised when creating a CryptContext instance
via any of its constructors, or when updating the configuration of an existing
instance:
| raises ValueError: |
|---|
| |
- If a configuration option contains an invalid value
(e.g.
all__vary_rounds=-1).
- If the configuration contains valid but incompatible options
(e.g. listing a scheme as both default
and deprecated).
|
| raises KeyError: |
|---|
| |
- If the configuration contains an unknown or forbidden option
(e.g.
scheme__salt).
- If the schemes,
default, or
deprecated options reference an unknown
hash scheme (e.g.
schemes=['xxx'])
|
| raises TypeError: |
|---|
| |
- If a configuration value has the wrong type (e.g.
schemes=123).
Note that this error shouldn’t occur when loading configurations
from a file/string (e.g. using CryptContext.from_string()).
|
Additionally, a PasslibConfigWarning may be issued
if any invalid-but-correctable values are encountered
(e.g. if sha256_crypt__min_rounds is set to less than
sha256_crypt ‘s minimum of 1000).
Changed in version 1.6: Previous releases used Python’s builtin UserWarning instead
of the more specific passlib.exc.PasslibConfigWarning.
