Advanced Usage
Avoiding Phishing Attacks
Phishing is a very common method used on the web to get people to unknowingly divulge sensitive information such as account credentials. It is generally accomplished by sending misleading URLs in email or placing them on websites. When you visit these URLs you are taken to a site that looks identical to the site you were expecting to go to in the hope that you are tricked into giving up your account credentials. It used to be that if you carefully inspected the URL you could spot deception, but even that is no longer true.
Avendesora helps you avoid phishing attacks in two ways. First, you should never go to one of your secure sites by clicking on a link. Instead, you should use Avendesora’s browse command:
avendesora browse chase
In this way you use the URL stored in Avendesora rather than trusting a URL
link provided by a third party. Second, you should auto-enter the account
credentials using Avendesora’s account discovery based on
avendesora.RecognizeURL
(be sure to use
avendesora.RecognizeURL
for websites rather than
avendesora.RecognizeTitle
when configuring account discovery,
avendesora.RecognizeURL
is not fooled by phishing sites).
Account Discovery
If you do not give an account to ‘avendesora value’, Avendesora tries to determine the account by simply asking each account if it is suitable. An account can look at the window title, the user name, the host name, the working directory, and the environment variables to determine if it is suitable. If so, it nominates itself. If there is only one account nominated, that account is used. If there are multiple nominees, then a small window pops up allowing you to choose which account you wish to use.
To configure an account to trigger when a particular window title is seen, use:
discovery = RecognizeTitle(
'Chase Online *',
script='{username}{tab}{passcode}{return}'
)
The title can either be a glob string or a function. For glob strings, ‘*’ matches any combination of characters and ‘?’ matches any single character (see fnmatch for a complete description of the glob syntax). In this way, the entire title must be matched. For functions, the argument is the title and the return value must be truthy if the title matched and falsey otherwise. The script describes what Avendesora should output when there is a match. In this case it outputs the username field, then a tab, then the passcode field, then a return (see Scripts).
Matching window titles can be fragile, especially for websites because the titles can vary quite a bit across the site and over time. To accommodate this variation, you can give multiple glob patterns:
discovery = RecognizeTitle(
'CHASE Bank*',
'Chase Online*',
script='{username}{tab}{passcode}{return}'
)
However, in general, it is better to match the URL. This can be done in Firefox
and Chrome by adding extensions that place the URL in the window title and then
using avendesora.RecognizeURL
to do the recognition.
If you use Firefox, you should install the Add URL to Window Title extension by Eric. It is a plugin that makes discovery easier and more robust by adding the URL to the title. For Chrome the appropriate plugin is is URL in Title by Guillaume Ryder. It is recommended that you install the appropriate one into your browser. For Add URL To Window Title, set the following options:
show full URL = yes
separator string = '-'
show field attributes = no
For URL in Title, set:
tab title format = '{title} - {protocol}://{hostname}{port}/{path}'
If you use qutebrowser as your browser, you should add the following to your ~/.config/qutebrowser/config.py file:
c.window.title_format = '{title} - {current_url} - qutebrowser'
avendesora.RecognizeURL
is designed to recognize such titles. Once you
have
deployed the appropriate plugin, you can use:
discovery = RecognizeURL(
'https://chaseonline.chase.com',
'https://www.chase.com',
script='{username}{tab}{passcode}{return}'
)
When giving the URL, anything specified must match and globbing is
not supported. If you give a partial path, by default Avendesora
matches up to what you have given, but you can require an exact
match of the entire path by specifying exact_path=True
to
avendesora.RecognizeURL
. If you do not give the protocol, the
default_protocol (https) is assumed.
In general you should use avendesora.RecognizeURL
rather than
avendesora.RecognizeTitle
for websites if you can. Doing so helps
protect you from phishing attacks by carefully examining the URL.
When account discovery fails it can be difficult to determine what is going wrong. When this occurs, you should first examine the log file:
> avendesora log
It should show you the window title and the recognized title components. You should first assure the title is as expected. If Add URL to Window Title or URL in Title generated the title, then the various title components should also be shown. Then run Avendesora as follows:
> avendesora value --verbose --title '<title>'
The title should be copied from the log file. The verbose option causes the result of each test to be included in the log file, so you can determine which recognizer is failing to trigger. You can either specify the verbose option on the command line or in the config file.
Recognizers
The following recognizers are available:
RecognizeAll(<recognizer>..., [script=<script>])
RecognizeAny(<recognizer>..., [script=<script>])
RecognizeTitle(<title>..., [script=<script>])
RecognizeURL(<title>..., [script=<script>, [name=<name>,]] [exact_path=<bool>])
RecognizeHost(<host>..., [script=<script>])
RecognizeUser(<user>..., [script=<script>])
RecognizeCWD(<cwd>..., [script=<script>])
RecognizeEnvVar(<name>, <value>, [script=<script>])
RecognizeNetwork(<mac>..., [script=<script>])
RecognizeFile(<path>, [<contents>,] [<ttl>,] [script=<script>])
avendesora.RecognizeAll
and avendesora.RecognizeAny
can be
used to combine several recognizers. For example:
discovery = RecognizeAll(
RecognizeTitle('sudo *'),
RecognizeUser('hhyde'),
script='{passcode}{return}'
)
If the recognizers are given in an array, all are tried, and each that match are offered. For example:
discovery = [
RecognizeURL(
'http://www.querty-forum.org',
script='admin{tab}{passcode}{return}',
name='admin',
),
RecognizeURL(
'http://www.querty-forum.org',
script='thecaretaker{tab}{passcode}{return}',
name='thecaretaker',
),
]
In this case, both recognizers recognize the same URL, thus they are both be offered for this site. But each has a different script. The name allows the user to distinguish the available choices.
If there is a need to distinguish URLs where is one is a substring of another, you can use exact_path:
discovery = [
RecognizeURL(
'https://mybank.com/Authentication',
script='{username}{return}',
exact_path=True,
),
RecognizeURL(
'https://mybank.com/Authentication/Password',
script='{passcode}{return}',
exact_path=True,
),
]
The URL may contain the # character. This character separates the ‘fragment’ from the rest of the URL. You can distinguish two otherwise indistinguishable URLs by their fragment. For example, BitWarden requests the username and password on a page with a URL of https://vault.bitwarden.com/#/ and it request only the password on a page with a URL of https://vault.bitwarden.com/#/lock. Normally the fragment (the part of the URL that follows the #) is ignored when determining whether a URL matches, however you can explicitly specify that it should be included as follows:
discovery = [
RecognizeURL(
'https://vault.bitwarden.com',
script='{email}{tab}{passcode}{return}',
fragment='/',
),
RecognizeURL(
'https://vault.bitwarden.com',
script='{passcode}{return}',
fragment='/lock',
),
]
avendesora.RecognizeFile
checks to determine whether a particular file
has been created recently. This can be use in scripts to force secret
recognition. For example, the titles used by Firefox and Thunderbird when
collecting the master password is either non-existent or undistinguished. These
programs also produce a large amount of uninteresting chatter on their output,
so it is common to write a shell script to run the program that redirects their
output to /dev/null. Such a script can be modified to essentially notify
Avendesora that a particular password is desired. For example, for
Thunderbird:
#!/bin/sh
touch /tmp/thunderbird-1024
/usr/bin/thunderbird > /dev/null
Here I have adding my user id (uid=1024) to make the filename unique so I am less likely to clash with other users. Alternately, I could have simply placed the file in my home directory.
Then, Avendesora will recognize Thunderbird if you add the following discovery field to your Thunderbird account:
class Thunderbird(Account):
desc = 'Master password for Thunderbird'
passcode = Password()
discovery = RecognizeFile(
'/tmp/thunderbird-1024', wait=60, script='{passcode}{return}'
)
If the specified file exists and has been updated within the last 60 seconds, then secret is recognized. You can specify the amount of time you can wait in between running the script and running Avendesora with the ‘wait’ argument, which takes a number of seconds. It defaults to 60.
Using this particular approach, every secret needs its own file. But you can share a file by specifying the file contents. Then the script could be rewritten as:
#!/bin/sh
echo thunderbird > ~/.avendesora-password-request
/usr/bin/thunderbird > /dev/null
Then you would add something like the following to your Thunderbird account entry:
class Thunderbird(Account):
desc = 'Master password for Thunderbird'
passcode = Password()
discovery = RecognizeFile(
'~/.avendesora-password-request',
contents='thunderbird',
script='{passcode}{return}'
)
Terminal Windows
It is generally possible to configure you terminal emulator to put the currently running command in the window title, which makes it available to Avendesora’s account discovery.
For this to work you need a terminal emulator that supports xterm’s special
characters for setting the window title, which is quite common. In this case,
sending a string to the window that starts with esc-]0;
and ends with
ctrl-g
will set the window title. How you generate these codes depends on
which shell you use.
Tcsh
Tcsh runs postcmd after it has read the command but before it is run. You can change postcmd by creating an alias of the same name. Here is a version that sets the window title to the currently running command:
alias postcmd 'echo -n "\033]2;${USER}@${HOST:r:r}: \!#\007"'
${USER}
is replaced by the username and ${HOST:r:r}
is replaced with the
hostname with two extensions removed. The \!#
is replaced by the currently
running command.
Running this alias command causes the window title to be set as a command starts. Still needed is to update the window title after the command completes. This is realized using the precmd command. Tcsh calls this command before generating a prompt. Here is a version that sets the window title to contain the hostname and the current working directory:
alias precmd 'echo -n "^[[]2;${USER}@${HOST:r:r}:${cwd}^G"'
Place both of these aliases in your ~/.cshrc file to configure your shell to keep your window title up-to-date. They should be placed at the end of the file and should only be executed for interactive shells:
if ($?prompt) then
alias precmd 'echo -n "^[]2;${USER}@${HOST:r:r}:${cwd}^G"'
alias postcmd 'echo -n "^[]2;${USER}@${HOST:r:r}: \!#^G"'
endif
With these aliases in place, you can add the following to the account that contains your login password:
discovery = RecognizeTitle(
'*@*: sudo *',
script='{passcode}{return}'
)
With this, you can run a sudo command in your shell, and trigger Avendesora when sudo requests your password. Avendesora will recognize the title and enter your login password. By placing the username and the host name in the window title along with the command you give Avendesora the ability to tailor its response accordingly. For example, you match a specific user and host names with the following:
discovery = RecognizeTitle(
'elayne@andor: sudo *',
script='{passcode}{return}'
)
Bash
The following code added to your ~/.bashrc file will accomplish pretty much the same thing if you use Bash as your shell:
HOST=$(echo "$HOSTNAME" | cut -f 1 -d '.')
trap 'printf "\033]0;${USER}@${HOST}: %s\007" "${BASH_COMMAND//[^[:print:]]/}"' DEBUG
Security Questions
Security questions are form of security theater imposed upon you by many websites. The claim is that these questions increase the security of your account. In fact they often do the opposite by creating additional avenues of access to your account. Their real purpose is to allow you to regain access to your account in case you lose your password. If you are careful, this is not needed (you do back up your Avendesora accounts, right?). In this case it is better to randomly generate your answers.
Security questions are handled by adding something like the following to your account:
questions = [
Question('oldest aunt?'),
Question('title of first job?'),
Question('oldest uncle?'),
Question('savings goal?'),
Question('childhood vacation spot?'),
]
The string identifying the question does not need to contain the question verbatim, a abbreviated version is sufficient as long as it allows you to distinguish the question. However, once set, you should not change the question in the slightest; doing so changes the generated answer.
The questions are given as an array, and so are accessed with an index that starts at 0. Thus, to get the answer to who is your ‘oldest aunt’, you would use:
> avendesora value <accountname> 0
questions.0 (oldest aunt): ampere reimburse duster
You can get a list of your questions and then select which one you want answered using the questions command. Specifically, if Citibank asks for the name of your oldest uncle you can use the following to find the answer:
> avendesora questions citi
0: oldest aunt?
1: title of first job?
2: oldest uncle?
3: savings goal?
4: childhood vacation spot?
Which question? 2
questions (oldest uncle?): discomfit correct contact
By default, Avendesora generates a response that consists of 3 random words. This makes it easy to read to a person over the phone if asked to confirm your identity. Occasionally you will not be able to enter your own answer, but must choose one that is offered to you. In this case, you can specify the answer as part of the question:
questions = [
Question('favorite fruit?', answer='grapes'),
Question('first major city visited?', answer='paris'),
Question('favorite subject?', answer='history'),
]
When giving the answers you may want to conceal them to protect them from casual observation.
Opening Accounts in your Browser
Avendesora provides the browse command to allow you to easily open the website for your account in your browser. To do so, it needs two things: a URL and a browser.
Selecting the URL
Avendesora looks for URLs in the urls and discovery account attributes, with urls being preferred if both exist. urls may either be a string, a list, or a dictionary. If it is a string, it is split at white spaces to make it a list. If urls is a list, the URLs are considered unnamed and the first one given is used. If it a dictionary, the URLs are named. When named, you may specify the URL you wish to use by specifying the name to the browse command. For example, consider a urls attribute that looks like this:
class Dragon(Account):
username = 'rand'
passcode = Passphrase()
urls = dict(
email = 'https://webmail.dragon.com',
vpn = 'https://vpn.dragon.com',
)
default_url = 'email'
You would access vpn with:
avendesora browse dragon vpn
By specifying default_url you indicate which URL is desired when you do not explicitly specify which you want on the browse command. In this way, you can access your email with either of the following:
avendesora browse dragon email
avendesora browse dragon
If urls is not given, Avendesora looks for URLs in
avendesora.RecognizeURL
members in the discovery attribute. If the
name argument is provided to avendesora.RecognizeURL
, it is treated
as a named URL, otherwise it is treated as an unnamed URL.
If named URLs are found in both urls and discovery they are all available to browse command, with those given in urls being preferred when the same name is found in both attributes.
Selecting the Browser
You can configure browsers for use by Avendesora using the browsers setting. By default, browsers contains the following:
browsers = dict(
f = 'firefox -new-tab {url}',
fp = 'firefox -private-window {url}',
c = 'google-chrome {url}',
ci = 'google-chrome --incognito {url}',
q = 'qutebrowser {url}',
t = 'torbrowser {url}',
x = 'xdg-open {url}',
)
Each entry pairs a key with a command. The command will be run with {url} replaced by the selected URL when the browser is selected. You can choose which browser is used by specifying the –browser command line option on the browse command, by adding the browser attribute to the account, or by specifying the default_browser setting in the config file. If more than one is specified, the command line option dominates over the account attribute, which dominates over the setting. By default, the default browser is x, which uses the default browser for your account.
Interactive Queries
Occasionally you may need several account values or you may be talking to an account services representative on the phone and may want to quickly respond to their questions such as ‘what is your account number?’ or ‘what is your verbal password?’. In these cases using the value command is cumbersome. Avendesora provides two interactive commands that can help out.
The questions command allows you to quickly see the available security questions and then answer them on demand. For example:
> avendesora questions bank
0: Mothers profession?
1: Last name of high school best friend?
2: Name of first pet?
Which question? 1
questions.1 (Last name of high school best friend?): dirge revel oboist
Which question?
You are presented the available questions and asked to choose one. In the example, 1 is entered and that question is answered by Avendesora. You can then request the answer to another question. This continues until you give an empty selection.
As a short cut, you can use q as the name of the command rather than questions.
By default the default_vector_field is queried, which is generally questions, however you can request any composite field:
> avendesora q bank accounts
checking:
savings:
credit:
Which question? checking
accounts.checking: 7610-40-9891
Which question?
The questions command is useful when confronting one or more unexpected challenge questions, but it only handles one composite field at a time. More convenient when chatting on the phone to an account representative is the interactive or i command. This command allows you to interactively query the value of any account field:
> avendesora interactive bank
which field? accounts.checking
accounts.checking: 7610-40-9891
which field?
An empty selection or <Ctrl-d> terminates the command. The command supports name completion using the <Tab> key. Simply type the first few characters of the name and type <Tab> to complete the name. Type <Tab><Tab> to get a list of available completions:
> avendesora i bank
which field? acc<Tab>.c<Tab>
accounts.checking: 7610-40-9891
which field?
If the value is a secret, it is displayed for a minute and then erased. To erase it early, type <Ctrl-c>.
One-Time Passwords
One-time passwords are often used as a second factor to provide an additional level of protection. They are especially useful when you are concerned about keyloggers.
Avendesora supports time-based one-time passwords (TOTP) that are fully compatible with, and can act as an alternative to or a replacement for, the Google Authenticator, Authy, or Symantec VIP apps.
Google Authenticator
When first enabling one-time passwords with Google Authenticator you are generally presented with a QR code. Also included is a string of characters that are often referred to as the backup code. You would provide this string of characters to the OTP class to configure an account for a one-time password. For example, here is an account that requests your username and password on one page, and your one time password on another:
class AndorSavings(Account):
email = 'lini.eltring@yahoo.com'
passcode = PasswordRecipe('16 2u 2d 2s')
otp = OTP('JBSWY3DPEHPK3PXP')
credentials = 'email passcode otp'
urls = 'https://www.andorsavings.com/login.html'
discovery = [
RecognizeURL(
'https://www.andorsavings.com/login.html',
script='{email}{tab}{passcode}{return}',
name='email & password',
),
RecognizeURL(
'https://www.andorsavings.com/googleVerify.html',
script='{otp}{return}',
name='authentication token',
),
]
Or, if you are lucky enough that they allow you to enter the OTP on the same page as your username and password, you might have:
class AndorSavings(Account):
email = 'lini.eltring@yahoo.com'
passcode = PasswordRecipe('16 2u 2d 2s')
otp = OTP('JBSWY3DPEHPK3PXP')
credentials = 'email passcode otp'
discovery = RecognizeURL(
'https://www.andorsavings.com/login.html',
script='{email}{tab}{passcode}{tab}{otp}{return}',
name='email, passcode and authentication token',
)
In this case, you only need one recognizer and specifying urls is no longer necessary because you only have one URL in the account.
This account adds a one time password as otp. It adds a credentials field that adds the one-time password to the output of the credentials command. It also adds a URL recognizer to allow semiautomatic entry of the one-time password to the browser.
Finally, some sites want you to concatenate the OTP to the end of your password. You can do that with:
script='{email}{tab}{passcode}{otp}{return}',
Authy
It is easy to mimic Google Authenticator. Mimicking Authy is more difficult. To do so, follow these instructions. Basically, the idea is to install the Authy Chrome app, start it, open the desired account, then back in Chrome open chrome://extensions, select Developer Mode, then click on ‘Inspect views: main.html’, search for totp function, set a break point in that function and wait until it trips, then copy the value of the e argument (a 32 digit hexadecimal number) to hex_seed in the code below:
#!/usr/bin/env python3
from base64 import b32encode, b32decode
from pyotp import TOTP
from time import sleep
def int_to_bytes(x):
return x.to_bytes((x.bit_length() + 7) // 8, 'big')
hex_seed = 0xNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
seed = b32encode(int_to_bytes(hex_seed))
print('SEED: %s' % seed)
otp = TOTP(seed, interval=10, digits=7)
print(otp.now())
sleep(10)
print(otp.now())
sleep(10)
print(otp.now())
sleep(10)
print(otp.now())
sleep(10)
print(otp.now())
Substitute your number for NNN…NN (hex_seed should be 0x followed by the value of e). Then run the script to display the seed or shared secret. It will also show five codes, one every 10 seconds. Every other code should match the value produced by the Chrome app. Be aware that every Authy app has its own seed, so the sequence that Chrome generates will be different from the sequence generated by your phone app or even a different Chrome app, and that is true even if they are generating tokens for the same account.
Once you are convinced that your seed is correct, add something like the following to your account to generate the one-time password:
otp = OTP('UM0HJVLT4HVWJQJC47Q8YXX4TU======', interval=10, digits=7)
The string passed to OTP should be the value of SEED as output by the above script. The interval and digits are specific to Authy.
Be aware that training Avendesora to output your Authy codes does not eliminate your need for the Authy application. Occasionally, an authorization request will be pushed to your Authy application to allow you to approve a transaction. Avendesora cannot provide this particular service. In the Authy parlance, Avendesora supports Authy Tokens, but not Authy Requests.
Symantec VIP
You can use vipaccess to generate OTP credentials for Avendesora that are compatible with the Symantec VIP authenticator application. Download and install vipaccess using:
git clone https://github.com/dlenski/python-vipaccess.git
cd python-vipaccess
pip3 install --user .
Once installed, you generate the credentials using:
vipaccess provision
It produces an ID, a secret, and an expiration date and places them into
~/.vipaccess.
The ID and secret are like a public and private key pair. You keep secret
private and you give the ID to the site when registering your authenticator.
With Avendesora you give the secret as the argument to
avendesora.OTP
.
As an example, consider configuring Avendesora to provide two-factor authentication for a Schwab account. Assume that you have run vipaccess and it generated the following ~/.vipaccess file:
version 1
secret AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
id VSST12345678
expiry 2019-01-15T12:00:00.000Z
You would configure Avendesora to generate one-time passwords by adding the following to the desired account:
otp = OTP('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA')
otp_expires = '2019-01-15T12:00:00.000Z'
The addition of otp_expires is not necessary, it just a way of keeping a useful piece of information in a convenient place. It is not necessary to save the ID.
You would register your authenticator with Schwab by giving them the ID, in this case VSST12345678, and the current one-time password, which you get with:
avendesora schwab otp
Once registered, Schwab expects you to add the one-time password to the end of your passcode when logging in. You can implement this in account discovery using:
discovery = RecognizeURL(
'https://client.schwab.com',
script='{username}{tab}{passcode}{otp}{return}',
)
You should now be able to login using a single keystroke.
Once you have registered and Avendesora is able to authenticate your access to Schwab, you can delete the ~/.vipaccess file.
You can add the one-time password to the credentials command in two alternate ways. In the first, you simply list out the one-time password along with the username and passcode:
credentials = 'username otp passcode'
Alternatively, you have Avendesora show the one-time password as part of the passcode, just as Schwab wants it. To accomplish this a new field, ephemeral_passcode, is created that combines the passcode and the one-time password. This field is replaces passcode in the credentials field:
ephemeral_passcode = Script('{passcode}{otp}')
credentials = 'username ephemeral_passcode'
In this example, the otp, otp_expires, and ephemeral_passcode field names are arbitrary. You are free to choose names more to your liking.
A variation on this process is used when registering Avendesora’s one-time password feature as a second-factor with ETrade. Symantec VIP has several types of tokens. By default, vipaccess generates VSST (desktop) tokens, but Etrade requires a VSMT (mobile) token. To generate a mobile token, use:
vipaccess provision -t VSMT
Except for this one detail, the rest of the process is the same as described for Schwab.
Scripts
Scripts are strings that contain embedded account attributes. For example:
'username: {username}, password: {passcode}'
When processed by Avendesora the attributes are replaced by their value from the chosen account. For example, this script might be rendered as:
username: rand_alThor, password: R7ibHyPjWtG2
You can specify a script directly to the value command.
You can specify them as account attributes (in this case then need to be
embedded in avendesora.Script
). Or you can specify them to
account discovery recognizers.
Besides account attributes, there are also some special codes that can be inserted in the script surrounded by braces:
Code |
Meaning |
---|---|
tab |
insert a tab character |
return |
insert a carriage return character |
sleep N |
pause for N seconds |
rate N |
set the autotype rate to one character per N milliseconds. |
paste field |
paste the value of the field using the primary selection |
remind msg |
show the msg as a notification |
tab and return are suitable for all scripts, but sleep, rate and remind are only suitable for account discovery scripts.
Scripts are useful if you need to combine an account value with other text, if you need to combine more than one account value, or if you want quick access to something that would otherwise need an additional key.
For example, consider an account for your wireless router, which might hold several passwords, one for administrative access and one or more for the network passwords. Such an account might look like:
class WiFi(Account):
username = 'admin'
passcode = Passphrase()
networks = ["Occam's Router", "Occam's Router (guest)"]
network_passwords = [Passphrase(), Passphrase()]
privileged = Script('''
SSID: {networks.0}
password: {network_passwords.0}
''')
guest = Script('''
SSID: {networks.1}
password: {network_passwords.1}
''')
credentials = 'privileged guest username passcode'
Notice that privileged and guest were specified as scripts. Now the credentials for the privileged network are accessed with:
> avendesora value wifi privileged
SSID: Occam's Router
password: overdraw cactus devotion saying
You can also give a script rather than a field on the command line when running the value command:
> avendesora value scc '{username}: {passcode}'
rand_alThor: R7ibHyPjWtG2
For example, a place where this is useful is when specifying a username and password to curl:
> curl --user `avendesora value -s apache '{username}:{passcode}'` ...
It is also possible to specify a script for the value of the default
attribute. This attribute allows you to specify the default field (which
attribute name and key to use if one is not given on the command line). It also
accepts a script rather than a field, but in this case it should be a simple
string and not an instance of the avendesora.Script
class. If you
passed it as a avendesora.Script
, it would be expanded before being
interpreted as a field name, and so would result in a ‘not found’ error.
class SCC(Account):
aliases = 'scc'
username = 'rand_alThor'
password = PasswordRecipe('12 2u 2d 2s')
default = 'username: {username}, password: {password}'
You can access the script by simply not providing a field:
> avendesora value scc
username: rand_alThor, password: *m7Aqj=XBAs7
Finally, you pass a script to the account discovery recognizers. They specify
the action that should be taken when a particular recognizer triggers. These
scripts would also be simple strings and not instances of the
avendesora.Script
class. For example, this recognizer could be used to
recognize Gmail:
discovery = [
RecognizeURL(
'https://accounts.google.com/ServiceLogin',
'https://accounts.google.com/signin/v2/identifier',
script='{username}{return}{sleep 2}{passcode}{return}'
name='username and passcode',
),
RecognizeURL(
'https://accounts.google.com/signin/v2/sl/pwd',
script='{passcode}{return}',
name='passcode',
),
RecognizeURL(
'https://accounts.google.com/signin/challenge',
script='{questions.0}{return}'
name='challenge',
),
]
Besides the account attributes, you can use several other special attributes including: {tab}, {return}, {sleep <N>}, {rate <N>}, *{paste <field>}, and {remind <message>}. {tab} is replaced by a tab character, {return} is replaced by a carriage return character, {sleep <N>} causes a pause of N seconds, {rate <N>} sets the autotype rate to one keystroke every *N milliseconds, {paste <field>} pastes the value of the given field using the middle mouse button, and {remind <message>} displays message as a notification. The sleep and rate functions are only active when auto-typing in account discovery.
The sleep function is useful with two-page authentication sites as it gives the website time to load the second page.
The rate function is useful with fields that have javascript helpers. The javascript helpers often limit the rate at which you can type characters. The rate function allows you to slow down the autotyping to the point where you avoid the problems that stem from exceeding the limit.
The paste is useful when trying to overcome JavaScript issues. Many websites use JavaScript to interpret the characters as you type them. This can be slow and may not be able to keep up with Avendesora’s auto-typing. There are various ways of overcoming this problem. You can use the rate function, or you can follow the field with the sleep function, or you can use the paste function to enter the value in one operation. Using paste can be more reliable than rate and sleep, which both count on timing that can vary with your internet connection. The paste occurs where the mouse is placed before the script is triggered, so it only really makes sense to use paste once in a script. If you are not pasting the first value in your script, then you should click on the first value to select it, then move the mouse without clicking so that hovers over the field to be pasted to, then trigger the script. A typical example script that employs paste is:
"{paste account}{tab}{passcode}{return}"
The remind function is used to remind you of next steps. For example, the following uses remind to instruct you to use your YubiKey to provide the second factor that completes the login process:
RecognizeURL(
'https://www.kraken.com/en-us/sign-in',
'https://www.kraken.com/sign-in',
script='{username}{tab}{passcode}{tab}{remind Use Yubikey as 2nd factor.}',
name = 'login',
)
Files as Secrets
It is possible to place the contents of entire files in Avendesora, and then when you request an account field that holds the file, that file is written to the filesystem.
To see how this would work, consider your SSH private keys. You would first encode each of the keys using the conceal command:
> avendesora conceal --file ~/ssh/id_rsa
Hidden(
'LS0tLS1CRUdJTiBPUEVOU1NIIFBSSVZBVEUgS0VZLS0tLS0KYjNCbGJuTnph'
...
'RCBPUEVOU1NIIFBSSVZBVEUgS0VZLS0tLS0K'
)
...
You would then create an Avendesora account for your SSH keys and copy the
encoded contents in to the arguments of avendesora.WriteFile
along with
the path to the file and the desired file mode:
class SSH_Keys(Account):
desc = 'ssh private keys'
aliases = 'sshkeys'
all = Script('\n {id_rsa}\n {github}')
id_rsa = WriteFile(
path = '~/.ssh/id_rsa',
contents = Hidden(
'LS0tLS1CRUdJTiBPUEVOU1NIIFBSSVZBVEUgS0VZLS0tLS0KYjNCbGJuTnph'
...
'RCBPUEVOU1NIIFBSSVZBVEUgS0VZLS0tLS0K'
),
mode = 0o0600
)
github = WriteFile(
path = '~/.ssh/github',
contents = Hidden(
'LS0tLS1CRUdJTiBPUEVOU1NIIFBSSVZBVEUgS0VZLS0tLS0KYjNCbGJuTnph'
...
'RXdIK1BWSTFmUUFBQUtpcDZsS1VxZXBTCmxB=='
),
mode = 0o0600
)
Then, when you run Avendesora the contents are decoded and written to the specified file:
> avendesora sshkeys id_rsa
id-rsa: Contents written to ~/.ssh/id_rsa.
Using avendesora.Script
allows you to write multiple files at once:
> avendesora sshkeys all
all:
Contents written to ~/.ssh/id_ed25519.
Contents written to ~/.ssh/id_rsa.
Stealth Accounts
Normally Avendesora uses information from an account that is contained in an accounts file to generate the secrets for that account. In some cases, the presence of the account itself, even though it is contained within an encrypted file can be problematic. The mere presence of an encrypted file may result in you being compelled to open it. For the most damaging secrets, it is best if there is no evidence that the secret exists at all. This is the purpose of stealth accounts (misdirection is an alternative to stealth accounts).
The stealth accounts are predefined and have names that are descriptive of the form of the secret they generate, for example word4 generates a 4-word pass phrase (also referred as the xkcd pattern):
> avendesora value word4
account: my_secret_account
gulch sleep scone halibut
The predefined accounts are kept in ~/.config/avendesora/stealth_accounts. You are free to add new accounts or modify the existing accounts.
Stealth accounts are subclasses of the avendesora.StealthAccount
class.
These accounts differ from normal accounts in that they do not contribute the
account name to the secrets generators for use as a seed. Instead, the user is
requested to provide the account name every time the secret is generated. The
secret depends strongly on this account name, so it is essential you give
precisely the same name each time. The term ‘account name’ is being use here,
but you can enter any text you like. Best to make this text very difficult to
guess if you are concerned about being compelled to disclose your GPG keys. You
would not want your spouse simply try ‘ashleymadison’ after you walk away from
your computer to gain access to your previously secret account.
The secret generator will combine the account name with the master seed before generating the secret. This allows you to use simple predictable account names and still get an unpredictable secret. The master seed used is taken from master_seed in the file that contains the stealth account if it exists, or the user_key if it does not. By default the stealth accounts file does not contain a master seed, which makes it difficult to share stealth accounts. You can create additional stealth account files that do contain master seeds that you can share with your associates.
Misdirection
One way to avoid being compelled to disclose a secret is to disavow any knowledge of the secret. However, the presence of an account in Avendesora that pertains to that secret undercuts this argument. This is the purpose of stealth accounts. They allow you to generate secrets for accounts for which Avendesora has no stored information. In this case Avendesora asks you for the minimal amount of information that it needs to generate the secret. However in some cases, the amount of information that must be retained is simply too much to keep in your head. In that case another approach, referred to as secret misdirection, can be used.
With secret misdirection, you do not disavow any knowledge of the secret, instead you say your knowledge is out of date. So you would say something like “I changed the password and then forgot it”, or “The account is closed”. To support this ruse, you must use the –seed (or -S) option to ‘avendesora value’ when generating your secret (secrets misdirection only works with generated passwords, not stored passwords). This causes Avendesora to ask you for an additional seed at the time you request the secret. If you do not use –seed or you do and give the wrong seed, you will get a different value for your secret. In effect, using –seed when generating the original value of the secret causes Avendesora to generate the wrong secret by default, allowing you to say “See, I told you it wouldn’t work”. But when you want it to work, you just interactively provide the correct seed.
You would typically only use misdirection for secrets you are worried about being compelled to disclose. So it behooves you to use an unpredictable additional seed for these secrets to reduce the chance someone could guess it.
Be aware that when you employ misdirection on a secret, the value of the secret stored in the archive will not be the true value, it will instead be the misdirected value.
Secret misdirection works extremely well with the ColdCard hardware bitcoin wallet. This wallet expects you to provide a PIN when accessing your wallet, but it does not print an error message if you give the wrong pin, instead it simply gives you access to a different wallet. Putting a small amount of bitcoin into the wallet you access with no seed makes the ruse more convincing. In this way, the wallet you get when you run:
avendesora value coldcard pin
opens a valid and active wallet that contains very little money. At this point you can say, “Yeah, its largely all gone. I was hacked. That is why I got this secure hardware wallet. However, it’s a lesson I learned too late.”. Then, when you are alone, you can run:
avendesora value --seed coldcard pin
and give the correct seed to access all your riches.
Collaborating with a Partner
If you share an accounts file with a partner, then either partner can create new secrets and the other partner can reproduce their values once a small amount of relatively non-confidential information is shared. This works because the security of the generated secrets is based on the master seed, and that seed is contained in the accounts file that is shared in a secure manner once at the beginning. For example, imagine one partner creates an account at the US Postal Service website and then informs the partner that the name of the new account is USPS and the username is taveren. That is enough information for the second partner to generate the password and login. And notice that the necessary information can be shared over an insecure channel. For example, it could be sent in a text message or from a phone where trustworthy encryption is not available.
The first step in using Avendesora to collaborate with a partner is for one of the partners to generate and then share an accounts file that is dedicated to the shared accounts. This file contains the master seed, and it is critical to keep this value secure. Thus, it is recommended that the file be shared in person or that it be encrypted in transit.
Consider an example where you, Siuan, are sharing accounts with your business partner, Moiraine. You have hired a contractor to run your email server, Elaida, who unbeknownst to you is reading your email in order to steal valuable secrets. Together, you and Moiraine jointly run Aes Sedai Enterprises. Since you expect more people will need access to the accounts in the future, you choose to the name the file after the company rather than your partner. To share accounts with Moiraine, you start by getting Moiraine’s public GPG key. Then, create the new accounts file with something like:
avendesora new -g siuan@aessedai.com,moiraine@aessedai.com aessedai.gpg
This generates a new accounts file, ~/.config/avendesora/aessedai.gpg, and encrypts it so only you and Moiraine can open it. Mail this file to Moiraine. Since it is encrypted, it is to safe to send the file through email. Even though Elaida can read this message, the accounts file is encrypted so she cannot access the master seed it contains. Moiraine should put the file in ~/.config/avendesora and then add it to accounts_files in ~/.config/avendesora/accounts_files. You are now ready to share accounts.
Then, when one partner creates a new account they mail the new account entry to the other partner. This entry does not contain enough information to allow an eavesdropper such as Elaida to be able to generate the secrets, but now both partners can. At a minimum you would need to share only the account name and the user name if one is needed. With that, the other partner can generate the passcode.
When creating accounts to share, the fields should either be generated secrets
or information that is not secret. Specifically, you should not use
avendesora.Hide
or avendesora.Hidden
. In addition, you cannot
share secrets encrypted with avendesora.Scrypt
. Finally, you cannot
share stealth accounts unless the file that contains the account templates has
a master_seed specified, which they do not by default. You would need to
create a separate file for shared stealth account templates and add a master
seed to that file manually.
Once you have shared an accounts file, you can also use the identity command to prove your identity to your partner (described next).
Confirming the Identity of a Partner
The identity command allows you to generate a response to any challenge. The response identifies you to a remote partner with whom you have shared an account.
If you run the command with no arguments, it prints the list of valid names. If you run it with no challenge, one is created for you based on the current time and date.
If you have a remote partner to whom you wish to prove your identity, have that partner use Avendesora to generate a challenge and a response based on your shared secret. Then the remote partner provides you with the challenge and you run Avendesora with that challenge to generate the same response, which you provide to your remote partner to prove your identity.
You are free to explicitly specify a challenge to start the process, but it is important that it be unpredictable and that you not use the same challenge twice. As such, it is recommended that you not provide the challenge. In this situation, one is generated for you based on the time and date.
Consider an example that illustrates the process. In this example, Siuan is confirming the identity of Moiraine, where both Siuan and Moiraine are assumed to have shared Avendesora accounts. Siuan runs Avendesora as follows and remembers the response:
> avendesora identity moiraine
challenge: slouch emirate bedeck brooding
response: spear disable local marigold
This assumes that moiraine is the name, with any extension removed, of the file that Siuan uses to contain their shared accounts.
Siuan communicates the challenge to Moiraine but not the response. Moiraine then runs Avendesora with the given challenge:
> avendesora identity siuan slouch emirate bedeck brooding
challenge: slouch emirate bedeck brooding
response: spear disable local marigold
In this example, siuan is the name of the file that Moiraine uses to contain their shared accounts.
To complete the process, Moiraine returns the response to Siuan, who compares it to the response she received to confirm Moiraine’s identity. If Siuan has forgotten the desired response, she can also specify the challenge to the identity command to regenerate the expected response.
Alternately, when Siuan sends a message to Moiraine, she can proactively prove her identity by providing both the challenge and the response. Moiraine could then run the credentials command with the challenge and confirm that she gets the same response. Other than herself, only Siuan could predict the correct response to any challenge. However, this is not recommended as it would allow someone with brief access to Suian’s Avendesora, perhaps Leane her Keeper, to generate and store multiple challenge/response pairs. Leane could then send messages to Moiraine while pretending to be Siuan using the saved challenge/response pairs. The subterfuge would not work if Moiraine generated the challenge unless Leane currently has access to Siuan’s Avendesora.
Phonetic Alphabet
When on the phone it can be difficult to convey the letters in an account identifier or other letter sequences. To help with this Avendesora can convert the sequence to the NATO phonetic alphabet. For example, imaging conveying the sequence ‘2WQI1T’. To do so, you can run the following:
> avendesora phonetic 2WQI1T
two whiskey quebec india one tango
Alternately, you can run the command without an argument, in which case it simply prints out the phonetic alphabet:
> avendesora p
Phonetic alphabet:
Alfa Echo India Mike Quebec Uniform Yankee
Bravo Foxtrot Juliett November Romeo Victor Zulu
Charlie Golf Kilo Oscar Sierra Whiskey
Delta Hotel Lima Papa Tango X-ray
Now you can easily do the conversion yourself. Having Avendesora do the conversion for you helps you distinguish similar looking characters such as I and 1 and O and 0.
Upgrading from Abraxas
Avendesora generalizes and replaces Abraxas, its predecessor. To transition from Abraxas to Avendesora, you will first need to upgrade Abraxas to version 1.8 or higher (use ‘abraxas -v’ to determine version). Then run:
abraxas --export
It will create a collection of Avendesora accounts files in ~/.config/abraxas/avendesora. You need to manually add these files to your list of accounts files in Avendesora. Say one such file is created: ~/.config/abraxas/avendesora/accounts.gpg. This could be added to Avendesora as follows:
create a symbolic link from ~/.config/avendesora/abraxas_accounts.gpg to ~/.config/abraxas/avendesora/accounts.gpg:
cd ~/.config/avendesora ln -s ../abraxas/avendesora/accounts.gpg abraxas_accounts.gpg
add abraxas_accounts.gpg to account_files list in accounts_files.
Now all of the Abraxas accounts contained in abraxas_accounts.gpg should be available though Avendesora and the various features of the account should operate as expected. However, secrets in accounts exported by Abraxas are no longer generated secrets. Instead, the actual secrets are placed in a hidden form in the exported accounts files.
If you would like to enhance the imported accounts to take advantage of the new features of Avendesora, it is recommended that you do not manually modify the imported files. Instead, copy the account information to one of your own account files before modifying it. To avoid conflict, you must then delete the account from the imported file. To do so, create ~/.config/abraxas/do-not-export if it does not exist, then add the account name to this file, and reexport your accounts from Abraxas.