NAME¶
dcmsign - Sign and Verify DICOM Files
SYNOPSIS¶
dcmsign [options] dcmfile-in [dcmfile-out]
DESCRIPTION¶
The
dcmsign utility reads a DICOM file (
dcmfile-in), performs a
digital signature operation and, if any modification has taken place, writes
the DICOM object to an output file (
dcmfile-out).
Five digital signature operations are supported:
- •
- verification of all signatures in the DICOM file
- •
- creation of a new digital signature located in the main dataset,
- •
- creation of a new digital signature in an item of a sequence embedded
within the dataset,
- •
- removal of a single digital signature from the DICOM file, and
- •
- removal of all digital signatures from the DICOM file.
PARAMETERS¶
dcmfile-in DICOM input filename to be processed
dcmfile-out DICOM output filename
OPTIONS¶
general options¶
-h --help
print this help text and exit
--version
print version information and exit
--arguments
print expanded command line arguments
-q --quiet
quiet mode, print no warnings and errors
-v --verbose
verbose mode, print processing details
-d --debug
debug mode, print debug information
-ll --log-level [l]evel: string constant
(fatal, error, warn, info, debug, trace)
use level l for the logger
-lc --log-config [f]ilename: string
use config file f for the logger
input file format:
+f --read-file
read file format or data set (default)
+fo --read-file-only
read file format only
-f --read-dataset
read data set without file meta information
input transfer syntax:
-t= --read-xfer-auto
use TS recognition (default)
-td --read-xfer-detect
ignore TS specified in the file meta header
-te --read-xfer-little
read with explicit VR little endian TS
-tb --read-xfer-big
read with explicit VR big endian TS
-ti --read-xfer-implicit
read with implicit VR little endian TS
signature commands¶
--verify
verify all signatures (default)
+s --sign [p]rivate key file, [c]ertificate file: string
create signature in main object
+si --sign-item [k]eyfile, [c]ertfile, [i]tem location: string
create signature in sequence item
+r --remove [s]ignature UID: string
remove signature
+ra --remove-all
remove all signatures from data set
signature creation options (only with --sign or --sign-item):¶
private key password:
+ps --std-passwd
prompt user to type password on stdin (default)
+pw --use-passwd [p]assword: string
use specified password
-pw --null-passwd
use empty string as password
key and certificate file format:
-pem --pem-keys
read keys/certificates as PEM file (default)
-der --der-keys
read keys/certificates as DER file
digital signature profile:
-pf --profile-none
don't enforce any signature profile (default)
+pb --profile-base
enforce base RSA signature profile
+pc --profile-creator
enforce creator RSA signature profile
+pa --profile-auth
enforce authorization signature profile
MAC algorithm:
+mr --mac-ripemd160
use RIPEMD 160 (default)
+ms --mac-sha1
use SHA-1
+mm --mac-md5
use MD 5
tag selection:
-t --tag
[t]ag: "gggg,eeee" or dictionary name
sign only specified tag
(this option can be specified multiple times)
-tf --tag-file [f]ilename: string
read list of tags from text file
signature format:
-fn --format-new
use correct DICOM signature format (default)
-fo --format-old
use old (pre-3.5.4) DCMTK signature format, non-conformant
if signature includes compressed pixel data
output options¶
output transfer syntax:
+t= --write-xfer-same
write with same TS as input (default)
+te --write-xfer-little
write with explicit VR little endian TS
+tb --write-xfer-big
write with explicit VR big endian TS
+ti --write-xfer-implicit
write with implicit VR little endian TS
length encoding in sequences and items:
+e --length-explicit
write with explicit lengths (default)
-e --length-undefined
write with undefined lengths
other output options:
+d --dump [f]ilename: string
dump byte stream fed into the MAC codec to file
(only with --sign or --sign-item)
NOTES¶
Files and Parameters¶
The
dcmsign utility reads and writes a number of files and file formats
which are described in this section.
Public Key Certificates are expected in X.509v3 format, either with PEM or DER
encoding. The dcmsign utility currently supports RSA and DSA public keys,
although only RSA keys are defines in the Security Profiles of the DICOM
standard.
Private Keys are expected in PEM or DER encoding. PEM is recommended (and
default) because this allows to keep private keys in encrypted form. Command
line options control the behaviour of
dcmsign when an encrypted PEM key
is opened (see above). In general it is not recommended to specify the
encryption password in the command line because the command line may be
visible to other processes in the system, e.g. 'ps -ef'.
The list of data elements to sign can either be read from a file or specified on
the command line or both (in this case the keys are combined).
On the command line, attribute keys are specified as
--tag "gggg,eeee" where gggg and eeee are the hexadecimal group
and element numbers
--tag "Name" where 'Name' is a symbolic attribute name from
the DICOM dictionary (see below).
When attribute tags are read from file with the
--tag-file option, a
plain text file of max. 64 kbyte is expected. Tags within the file are either
symbolic names from the data dictionary or have the format (gggg,eeee) (with
braces). Tags are separated by one or more whitespace characters.
The
--sign-item operation requires a location string that describes in
which sequence item a signature is to be created. The location string has the
following format:
SequenceName[index].SequenceName[index].SequenceName[index](...)
where SequenceName is either a symbolic attribute name from the data dictionary
or a numeric tag in the format (gggg,eeee) and index is an unsigned decimal
integer for the item number, starting with zero for the first item in a
sequence. As an example, the following location string
ReferencedSeriesSequence[0].ReferencedImageSequence[1]
would cause a digital signature to be created in the second item of the
ReferencedImageSequence (0008,1140) which is located in the first item of the
ReferencedSeriesSequence (0008,1115) which is located in the main DICOM
dataset.
LOGGING¶
The level of logging output of the various command line tools and underlying
libraries can be specified by the user. By default, only errors and warnings
are written to the standard error stream. Using option
--verbose also
informational messages like processing details are reported. Option
--debug can be used to get more details on the internal activity, e.g.
for debugging purposes. Other logging levels can be selected using option
--log-level. In
--quiet mode only fatal errors are reported. In
such very severe error events, the application will usually terminate. For
more details on the different logging levels, see documentation of module
'oflog'.
In case the logging output should be written to file (optionally with logfile
rotation), to syslog (Unix) or the event log (Windows) option
--log-config can be used. This configuration file also allows for
directing only certain messages to a particular output stream and for
filtering certain messages based on the module or application where they are
generated. An example configuration file is provided in
<etcdir>/logger.cfg).
COMMAND LINE¶
All command line tools use the following notation for parameters: square
brackets enclose optional values (0-1), three trailing dots indicate that
multiple values are allowed (1-n), a combination of both means 0 to n values.
Command line options are distinguished from parameters by a leading '+' or '-'
sign, respectively. Usually, order and position of command line options are
arbitrary (i.e. they can appear anywhere). However, if options are mutually
exclusive the rightmost appearance is used. This behaviour conforms to the
standard evaluation rules of common Unix shells.
In addition, one or more command files can be specified using an '@' sign as a
prefix to the filename (e.g.
@command.txt). Such a command argument is
replaced by the content of the corresponding text file (multiple whitespaces
are treated as a single separator unless they appear between two quotation
marks) prior to any further evaluation. Please note that a command file cannot
contain another command file. This simple but effective approach allows to
summarize common combinations of options/parameters and avoids longish and
confusing command lines (an example is provided in file
<datadir>/dumppat.txt).
ENVIRONMENT¶
The
dcmsign utility will attempt to load DICOM data dictionaries
specified in the
DCMDICTPATH environment variable. By default, i.e. if
the
DCMDICTPATH environment variable is not set, the file
<datadir>/dicom.dic will be loaded unless the dictionary is built
into the application (default for Windows).
The default behaviour should be preferred and the
DCMDICTPATH environment
variable only used when alternative data dictionaries are required. The
DCMDICTPATH environment variable has the same format as the Unix shell
PATH variable in that a colon (':') separates entries. On Windows
systems, a semicolon (';') is used as a separator. The data dictionary code
will attempt to load each file specified in the
DCMDICTPATH environment
variable. It is an error if no data dictionary can be loaded.
COPYRIGHT¶
Copyright (C) 2000-2010 by OFFIS e.V., Escherweg 2, 26121 Oldenburg,
Germany.