openssl-ts, ts - Time Stamping Authority tool (client/server)
openssl ts -query [-rand file...]
[-writerand file] [-config configfile] [-data
file_to_hash] [-digest digest_bytes]
[-digest] [-tspolicy object_id]
[-no_nonce] [-cert] [-in request.tsq] [-out
request.tsq] [-text]
openssl ts -reply [-config configfile]
[-section tsa_section] [-queryfile request.tsq]
[-passin password_src] [-signer tsa_cert.pem] [-inkey
file_or_id] [-digest] [-chain
certs_file.pem] [-tspolicy object_id] [-in response.tsr]
[-token_in] [-out response.tsr] [-token_out]
[-text] [-engine id]
openssl ts -verify [-data
file_to_hash] [-digest digest_bytes] [-queryfile request.tsq]
[-in response.tsr] [-token_in] [-CApath
trusted_cert_path] [-CAfile trusted_certs.pem] [-untrusted
cert_file.pem] [verify options]
verify options: [-attime timestamp] [-check_ss_sig]
[-crl_check] [-crl_check_all] [-explicit_policy] [-extended_crl]
[-ignore_critical] [-inhibit_any] [-inhibit_map] [-issuer_checks]
[-no_alt_chains] [-no_check_time] [-partial_chain] [-policy arg]
[-policy_check] [-policy_print] [-purpose purpose] [-suiteB_128]
[-suiteB_128_only] [-suiteB_192] [-trusted_first] [-use_deltas] [-auth_level
num] [-verify_depth num] [-verify_email email] [-verify_hostname hostname]
[-verify_ip ip] [-verify_name name] [-x509_strict]
The ts command is a basic Time Stamping Authority (TSA)
client and server application as specified in RFC 3161 (Time-Stamp Protocol,
TSP). A TSA can be part of a PKI deployment and its role is to provide long
term proof of the existence of a certain datum before a particular time.
Here is a brief description of the protocol:
- 1.
- The TSA client computes a one-way hash value for a data file and sends the
hash to the TSA.
- 2.
- The TSA attaches the current date and time to the received hash value,
signs them and sends the timestamp token back to the client. By creating
this token the TSA certifies the existence of the original data file at
the time of response generation.
- 3.
- The TSA client receives the timestamp token and verifies the signature on
it. It also checks if the token contains the same hash value that it had
sent to the TSA.
There is one DER encoded protocol data unit defined for
transporting a timestamp request to the TSA and one for sending the
timestamp response back to the client. The ts command has three main
functions: creating a timestamp request based on a data file, creating a
timestamp response based on a request, verifying if a response corresponds
to a particular request or a data file.
There is no support for sending the requests/responses
automatically over HTTP or TCP yet as suggested in RFC 3161. The users must
send the requests either by ftp or e-mail.
The -query switch can be used for creating and printing a
timestamp request with the following options:
- -rand file...
- A file or files containing random data used to seed the random number
generator. Multiple files can be specified separated by an OS-dependent
character. The separator is ; for MS-Windows, , for OpenVMS,
and : for all others.
- [-writerand file]
- Writes random data to the specified file upon exit. This can be
used with a subsequent -rand flag.
- -config
configfile
- The configuration file to use. Optional; for a description of the default
value, see "COMMAND SUMMARY" in openssl(1).
- -data
file_to_hash
- The data file for which the timestamp request needs to be created. stdin
is the default if neither the -data nor the -digest
parameter is specified. (Optional)
- -digest
digest_bytes
- It is possible to specify the message imprint explicitly without the data
file. The imprint must be specified in a hexadecimal format, two
characters per byte, the bytes optionally separated by colons (e.g.
1A:F6:01:... or 1AF601...). The number of bytes must match the message
digest algorithm in use. (Optional)
- -digest
- The message digest to apply to the data file. Any digest supported by the
OpenSSL dgst command can be used. The default is SHA-1.
(Optional)
- -tspolicy
object_id
- The policy that the client expects the TSA to use for creating the
timestamp token. Either the dotted OID notation or OID names defined in
the config file can be used. If no policy is requested the TSA will use
its own default policy. (Optional)
- -no_nonce
- No nonce is specified in the request if this option is given. Otherwise a
64 bit long pseudo-random none is included in the request. It is
recommended to use nonce to protect against replay-attacks.
(Optional)
- -cert
- The TSA is expected to include its signing certificate in the response.
(Optional)
- -in request.tsq
- This option specifies a previously created timestamp request in DER format
that will be printed into the output file. Useful when you need to examine
the content of a request in human-readable format. (Optional)
- -out request.tsq
- Name of the output file to which the request will be written. Default is
stdout. (Optional)
- -text
- If this option is specified the output is human-readable text format
instead of DER. (Optional)
A timestamp response (TimeStampResp) consists of a response status
and the timestamp token itself (ContentInfo), if the token generation was
successful. The -reply command is for creating a timestamp response
or timestamp token based on a request and printing the response/token in
human-readable format. If -token_out is not specified the output is
always a timestamp response (TimeStampResp), otherwise it is a timestamp
token (ContentInfo).
- -config
configfile
- The configuration file to use. Optional; for a description of the default
value, see "COMMAND SUMMARY" in openssl(1). See
CONFIGURATION FILE OPTIONS for configurable variables.
- -section
tsa_section
- The name of the config file section containing the settings for the
response generation. If not specified the default TSA section is used, see
CONFIGURATION FILE OPTIONS for details. (Optional)
- -queryfile
request.tsq
- The name of the file containing a DER encoded timestamp request.
(Optional)
- -passin
password_src
- Specifies the password source for the private key of the TSA. See
"Pass Phrase Options" in openssl(1). (Optional)
- -signer
tsa_cert.pem
- The signer certificate of the TSA in PEM format. The TSA signing
certificate must have exactly one extended key usage assigned to it:
timeStamping. The extended key usage must also be critical, otherwise the
certificate is going to be refused. Overrides the signer_cert
variable of the config file. (Optional)
- -inkey
file_or_id
- The signer private key of the TSA in PEM format. Overrides the
signer_key config file option. (Optional) If no engine is used, the
argument is taken as a file; if an engine is specified, the argument is
given to the engine as a key identifier.
- -digest
- Signing digest to use. Overrides the signer_digest config file
option. (Mandatory unless specified in the config file)
- -chain
certs_file.pem
- The collection of certificates in PEM format that will all be included in
the response in addition to the signer certificate if the -cert
option was used for the request. This file is supposed to contain the
certificate chain for the signer certificate from its issuer upwards. The
-reply command does not build a certificate chain automatically.
(Optional)
- -tspolicy
object_id
- The default policy to use for the response unless the client explicitly
requires a particular TSA policy. The OID can be specified either in
dotted notation or with its name. Overrides the default_policy
config file option. (Optional)
- -in
response.tsr
- Specifies a previously created timestamp response or timestamp token (if
-token_in is also specified) in DER format that will be written to
the output file. This option does not require a request, it is useful e.g.
when you need to examine the content of a response or token or you want to
extract the timestamp token from a response. If the input is a token and
the output is a timestamp response a default 'granted' status info is
added to the token. (Optional)
- -token_in
- This flag can be used together with the -in option and indicates
that the input is a DER encoded timestamp token (ContentInfo) instead of a
timestamp response (TimeStampResp). (Optional)
- -out
response.tsr
- The response is written to this file. The format and content of the file
depends on other options (see -text, -token_out). The
default is stdout. (Optional)
- -token_out
- The output is a timestamp token (ContentInfo) instead of timestamp
response (TimeStampResp). (Optional)
- -text
- If this option is specified the output is human-readable text format
instead of DER. (Optional)
- -engine id
- Specifying an engine (by its unique id string) will cause ts
to attempt to obtain a functional reference to the specified engine, thus
initialising it if needed. The engine will then be set as the default for
all available algorithms. Default is builtin. (Optional)
The -verify command is for verifying if a timestamp
response or timestamp token is valid and matches a particular timestamp
request or data file. The -verify command does not use the
configuration file.
- -data
file_to_hash
- The response or token must be verified against file_to_hash. The file is
hashed with the message digest algorithm specified in the token. The
-digest and -queryfile options must not be specified with
this one. (Optional)
- -digest
digest_bytes
- The response or token must be verified against the message digest
specified with this option. The number of bytes must match the message
digest algorithm specified in the token. The -data and
-queryfile options must not be specified with this one.
(Optional)
- -queryfile
request.tsq
- The original timestamp request in DER format. The -data and
-digest options must not be specified with this one.
(Optional)
- -in
response.tsr
- The timestamp response that needs to be verified in DER format.
(Mandatory)
- -token_in
- This flag can be used together with the -in option and indicates
that the input is a DER encoded timestamp token (ContentInfo) instead of a
timestamp response (TimeStampResp). (Optional)
- -CApath
trusted_cert_path
- The name of the directory containing the trusted CA certificates of the
client. See the similar option of verify(1) for additional details.
Either this option or -CAfile must be specified. (Optional)
- -CAfile
trusted_certs.pem
- The name of the file containing a set of trusted self-signed CA
certificates in PEM format. See the similar option of verify(1) for
additional details. Either this option or -CApath must be
specified. (Optional)
- -untrusted
cert_file.pem
- Set of additional untrusted certificates in PEM format which may be needed
when building the certificate chain for the TSA's signing certificate.
This file must contain the TSA signing certificate and all intermediate CA
certificates unless the response includes them. (Optional)
- verify
options
- The options -attime timestamp, -check_ss_sig,
-crl_check, -crl_check_all, -explicit_policy,
-extended_crl, -ignore_critical, -inhibit_any,
-inhibit_map, -issuer_checks, -no_alt_chains,
-no_check_time, -partial_chain, -policy,
-policy_check, -policy_print, -purpose,
-suiteB_128, -suiteB_128_only, -suiteB_192,
-trusted_first, -use_deltas, -auth_level,
-verify_depth, -verify_email, -verify_hostname,
-verify_ip, -verify_name, and -x509_strict can be
used to control timestamp verification. See verify(1).
The -query and -reply commands make use of a
configuration file. See config(5) for a general description of the
syntax of the config file. The -query command uses only the symbolic
OID names section and it can work without it. However, the -reply
command needs the config file for its operation.
When there is a command line switch equivalent of a variable the
switch always overrides the settings in the config file.
- tsa section,
default_tsa
- This is the main section and it specifies the name of another section that
contains all the options for the -reply command. This default
section can be overridden with the -section command line switch.
(Optional)
- oid_file
- See ca(1) for description. (Optional)
- oid_section
- See ca(1) for description. (Optional)
- RANDFILE
- See ca(1) for description. (Optional)
- serial
- The name of the file containing the hexadecimal serial number of the last
timestamp response created. This number is incremented by 1 for each
response. If the file does not exist at the time of response generation a
new file is created with serial number 1. (Mandatory)
- crypto_device
- Specifies the OpenSSL engine that will be set as the default for all
available algorithms. The default value is builtin, you can specify any
other engines supported by OpenSSL (e.g. use chil for the NCipher HSM).
(Optional)
- signer_cert
- TSA signing certificate in PEM format. The same as the -signer
command line option. (Optional)
- certs
- A file containing a set of PEM encoded certificates that need to be
included in the response. The same as the -chain command line
option. (Optional)
- signer_key
- The private key of the TSA in PEM format. The same as the -inkey
command line option. (Optional)
- signer_digest
- Signing digest to use. The same as the -digest
command line option. (Mandatory unless specified on the command line)
- default_policy
- The default policy to use when the request does not mandate any policy.
The same as the -tspolicy command line option. (Optional)
- other_policies
- Comma separated list of policies that are also acceptable by the TSA and
used only if the request explicitly specifies one of them. (Optional)
- digests
- The list of message digest algorithms that the TSA accepts. At least one
algorithm must be specified. (Mandatory)
- accuracy
- The accuracy of the time source of the TSA in seconds, milliseconds and
microseconds. E.g. secs:1, millisecs:500, microsecs:100. If any of the
components is missing zero is assumed for that field. (Optional)
- clock_precision_digits
- Specifies the maximum number of digits, which represent the fraction of
seconds, that need to be included in the time field. The trailing zeros
must be removed from the time, so there might actually be fewer digits, or
no fraction of seconds at all. Supported only on UNIX platforms. The
maximum value is 6, default is 0. (Optional)
- ordering
- If this option is yes the responses generated by this TSA can always be
ordered, even if the time difference between two responses is less than
the sum of their accuracies. Default is no. (Optional)
- tsa_name
- Set this option to yes if the subject name of the TSA must be included in
the TSA name field of the response. Default is no. (Optional)
- ess_cert_id_chain
- The SignedData objects created by the TSA always contain the certificate
identifier of the signing certificate in a signed attribute (see RFC 2634,
Enhanced Security Services). If this option is set to yes and either the
certs variable or the -chain option is specified then the
certificate identifiers of the chain will also be included in the
SigningCertificate signed attribute. If this variable is set to no, only
the signing certificate identifier is included. Default is no.
(Optional)
- ess_cert_id_alg
- This option specifies the hash function to be used to calculate the TSA's
public key certificate identifier. Default is sha1. (Optional)
All the examples below presume that OPENSSL_CONF is set to
a proper configuration file, e.g. the example configuration file
openssl/apps/openssl.cnf will do.
To create a timestamp request for design1.txt with SHA-1 without
nonce and policy and no certificate is required in the response:
openssl ts -query -data design1.txt -no_nonce \
-out design1.tsq
To create a similar timestamp request with specifying the message
imprint explicitly:
openssl ts -query -digest b7e5d3f93198b38379852f2c04e78d73abdd0f4b \
-no_nonce -out design1.tsq
To print the content of the previous request in human readable
format:
openssl ts -query -in design1.tsq -text
To create a timestamp request which includes the MD-5 digest of
design2.txt, requests the signer certificate and nonce, specifies a policy
id (assuming the tsa_policy1 name is defined in the OID section of the
config file):
openssl ts -query -data design2.txt -md5 \
-tspolicy tsa_policy1 -cert -out design2.tsq
Before generating a response a signing certificate must be created
for the TSA that contains the timeStamping critical extended key
usage extension without any other key usage extensions. You can add this
line to the user certificate section of the config file to generate a proper
certificate;
extendedKeyUsage = critical,timeStamping
See req(1), ca(1), and x509(1) for
instructions. The examples below assume that cacert.pem contains the
certificate of the CA, tsacert.pem is the signing certificate issued by
cacert.pem and tsakey.pem is the private key of the TSA.
To create a timestamp response for a request:
openssl ts -reply -queryfile design1.tsq -inkey tsakey.pem \
-signer tsacert.pem -out design1.tsr
If you want to use the settings in the config file you could just
write:
openssl ts -reply -queryfile design1.tsq -out design1.tsr
To print a timestamp reply to stdout in human readable format:
openssl ts -reply -in design1.tsr -text
To create a timestamp token instead of timestamp response:
openssl ts -reply -queryfile design1.tsq -out design1_token.der -token_out
To print a timestamp token to stdout in human readable format:
openssl ts -reply -in design1_token.der -token_in -text -token_out
To extract the timestamp token from a response:
openssl ts -reply -in design1.tsr -out design1_token.der -token_out
To add 'granted' status info to a timestamp token thereby creating
a valid response:
openssl ts -reply -in design1_token.der -token_in -out design1.tsr
To verify a timestamp reply against a request:
openssl ts -verify -queryfile design1.tsq -in design1.tsr \
-CAfile cacert.pem -untrusted tsacert.pem
To verify a timestamp reply that includes the certificate
chain:
openssl ts -verify -queryfile design2.tsq -in design2.tsr \
-CAfile cacert.pem
To verify a timestamp token against the original data file:
openssl ts -verify -data design2.txt -in design2.tsr \
-CAfile cacert.pem
To verify a timestamp token against a message imprint:
openssl ts -verify -digest b7e5d3f93198b38379852f2c04e78d73abdd0f4b \
-in design2.tsr -CAfile cacert.pem
You could also look at the 'test' directory for more examples.
- No support for timestamps over SMTP, though it is quite easy to implement
an automatic e-mail based TSA with procmail(1) and perl(1).
HTTP server support is provided in the form of a separate apache module.
HTTP client support is provided by tsget(1). Pure TCP/IP protocol
is not supported.
- The file containing the last serial number of the TSA is not locked when
being read or written. This is a problem if more than one instance of
openssl(1) is trying to create a timestamp response at the same
time. This is not an issue when using the apache server module, it does
proper locking.
- Look for the FIXME word in the source files.
- The source code should really be reviewed by somebody else, too.
- More testing is needed, I have done only some basic tests (see
test/testtsa).
Copyright 2006-2021 The OpenSSL Project Authors. All Rights
Reserved.
Licensed under the OpenSSL license (the "License"). You
may not use this file except in compliance with the License. You can obtain
a copy in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.