dcmsign(1)                        OFFIS DCMTK                       dcmsign(1)

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 ("-" for stdin)

       dcmfile-out  DICOM output filename ("-" for stdout)

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 options
       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

       handling of defined length UN elements:

         -uc   --retain-un
                 retain elements as UN (default)

         +uc   --convert-un
                 convert to real VR if known

   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

         +t    --insert-timestamp  ts[q]file, ts[r]file [u]idfile: string
                 insert certified timestamp from ts response r
                 from timestamp query q at signature UID u

         +r    --remove  [s]ignature UID: string
                 remove signature

         +ra   --remove-all
                 remove all signatures from data set

   general signature options
       key and certificate file format:

         -pem  --pem-keys
                 read keys/certificates as PEM file (default)

         -der  --der-keys
                 read keys/certificates as DER 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. This option should
                 only be used to verify signatures in the old format.

   signature verification options (only with &ndash;verify)
       signature verification:

         +rv   --verify-if-present
                 verify signatures if present, pass otherwise
                 (default)

         +rg   --require-sig
                 fail if no signature at all is present

         +rc   --require-creator
                 fail if no creator RSA signature is present

         +ru   --require-auth
                 fail if no auth RSA signature is present

         +rs   --require-sr
                 fail if no SR RSA signature is present

       timestamp verification:

         +tv   --verify-ts
                 verify certified timestamp if present (default)

         -tv   --ignore-ts
                 ignore certified timestamps

         +tr   --require-ts
                 fail if no certified timestamp is present

       certification authority:

         +cf   --add-cert-file
                 [f]ilename: string
                 add trusted certificate file to cert store

         +uf   --add-ucert-file
                 [f]ilename: string
                 add untrusted intermediate certificate file

         +cd   --add-cert-dir
                 [d]irectory: string
                 add certificates in d to cert store

         +cr   --add-crl-file
                 [f]ilename: string
                 add certificate revocation list file
                 (implies --enable-crl-vfy)

         +cl   --enable-crl-vfy
                 enable certificate revocation list verification.fi

   signature creation options (only with &ndash;sign or &ndash;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

       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

         +pr   --profile-sr
                 enforce SR RSA signature profile

         +pv   --profile-srv
                 enforce SR RSA signature profile (verification)

       MAC algorithm:

         +mr   --mac-ripemd160
                 use RIPEMD 160 (default)

         +ms   --mac-sha1
                 use SHA-1

         +mm   --mac-md5
                 use MD 5

         +m2   --mac-sha256
                 use SHA-256

         +m3   --mac-sha384
                 use SHA-384

         +m5   --mac-sha512
                 use SHA-512

       signature purpose:

         +lp   --list-purposes
                 show list of signature purpose codes and exit

         -sp   --no-sig-purpose
                 do not add signature purpose (default)

         +sp   --sig-purpose
                 [p]urpose code: integer (1..18)
                 add digital signature purpose code p

       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.fi

   timestamp creation options (only with &ndash;sign or &ndash;sign-item)
       timestamp creation:

         -ts   --timestamp-off
                 do not create timestamp (default)

         +ts   --timestamp-file  [t]sq-filename, [u]id-filename: string
                 create timestamp query file t and uid file u

       timestamp MAC algorithm (only with --timestamp-file):

         +tm2  --ts-mac-sha256
                 use SHA-256 (default)

         +tm3  --ts-mac-sha384
                 use SHA-384

         +tm5  --ts-mac-sha512
                 use SHA-512

         +tmr  --ts-mac-ripemd160
                 use RIPEMD 160

         +tms  --ts-mac-sha1
                 use SHA-1 (not recommended)

         +tmm  --ts-mac-md5
                 use MD5 (not recommended)

       timestamp query nonce options (only with --timestamp-file):

         +tn   --ts-use-nonce
                 include random nonce (default)

         -tn   --ts-no-nonce
                 do not include nonce

       timestamp certificate inclusion options (only with --timestamp-file):

         +tc   --ts-request-cert
                 request TSA certificate in timestamp (default)

         -tc   --ts-no-cert
                 do not request TSA certificate in timestamp

       timestamp policy options (only with --timestamp-file):

         -tp   --ts-no-policy
                 do not specify ts policy (default)

         +tp   --ts-policy  [p]olicy-OID: string
                 request timestamp policy p

   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 one to keep private keys in encrypted
       form.  Command  line  options  control  the behavior 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'.

       By  default, dcmsign will create a signature covering all data elements
       in the dataset or item. This default can be  overridden  by  explicitly
       specifying  a  list  of  data  elements (attribute tags). This list can
       either be read from a file or specified on the command line or both (in
       this case the attribute tags are combined).

       On the command line, attribute tags 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 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 currently selected digital signature profile may specify additional
       attribute  tags required to be included in the signature, which will be
       silently added.

       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.

   Certified Timestamps
       Starting with release  3.6.6,  dcmsign  offers  support  for  certified
       timestamps  according to RFC 3161. For now, the tool does not implement
       any of the network protocols defined in RFC 3161 for communicating with
       a timestamp authority (TSA), but it can write a timestamp  query  (TSQ)
       during  signature creation, and the new command --insert-timestamp will
       read a timestamp response (TSR) from file  and  add  it  to  the  DICOM
       digital  signature. Since a DICOM file can contain multiple signatures,
       a 'UID file' (which contains the Digital  Signature  UID)  is  used  to
       identify  the  signature  to which the TSR should be added. The dcmsign
       tool will also perform various consistency checks  before  storing  the
       timestamp.

       During  signature  verification,  the presence of a certified timestamp
       will be detected and the timestamp will also be verified unless  option
       --ignore-ts was used. Signature verification and timestamp verification
       use  a  common certificate store to check the certificates of the DICOM
       signature and the timestamp. This  store  can  be  populated  with  the
       options  --add-cert-file  and --add-cert-dir, which both add trusted CA
       certificates, --add-ucert-file, which adds an untrusted intermediate CA
       certificate, and --add-crl-file, which adds  a  certificate  revocation
       list.

   Hashed Certificate Directories
       Instead  of  adding  CA  certificates  and certificate revocation lists
       (CRLs) manually using --add-cert-file and --add-crl-file, the user  can
       set-up a directory where dcmsign will look-up and load certificates and
       CRLs from as needed, using --add-cert-dir.

       Th  directory  should  contain  one  certificate or CRL per file in PEM
       format, with a filename of  the  form  hash.N  for  a  certificate,  or
       hash.rN for a CRL. The hash is the value returned by

       openssl  x509  -hash  -noout  -in  <filename.pem>  (for  a certificate)
       openssl crl -hash -noout -in <filename.pem> (for a CRL)

       The .N or .rN suffix is a sequence number that starts at zero,  and  is
       incremented  consecutively  for  each  certificate or CRL with the same
       hash value. Gaps in the sequence  numbers  are  not  supported,  it  is
       assumed  that  there  are no more objects with the same hash beyond the
       first missing number in the sequence.

       CRLs will only be verified when option --enable-crl-vfy  is  specified.
       In  this  case, dcmsign will expect a CRL to be present for each CA and
       will fail signature verification if no CRL can be found for the CA that
       issued the signer certificate.

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
       behavior  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  one  to  summarize  common
       combinations  of  options/parameters  and  avoids longish and confusing
       command lines (an example is provided in file <datadir>/dumppat.txt).

EXIT CODES
       The dcmsign utility uses the following  exit  codes  when  terminating.
       This  enables  the  user  to  check  for the reason why the application
       terminated.

   general
       EXITCODE_NO_ERROR                         0
       EXITCODE_COMMANDLINE_SYNTAX_ERROR         1
       EXITCODE_NOOPENSSL                        5

   input file errors
       EXITCODE_CANNOT_READ_INPUT_FILE          20
       EXITCODE_NO_INPUT_FILES                  21
       EXITCODE_CANNOT_READ_TAG_FILE            30
       EXITCODE_CANNOT_READ_TSQ_FILE            31
       EXITCODE_CANNOT_READ_TSR_FILE            32
       EXITCODE_CANNOT_READ_UID_FILE            33

   output file errors
       EXITCODE_CANNOT_WRITE_OUTPUT_FILE        40
       EXITCODE_CANNOT_WRITE_SUPPORT_FILE       46

   processing errors
       EXITCODE_CANNOT_ACCESS_SIGNATURE         80
       EXITCODE_CANNOT_ACCESS_TS                81
       EXITCODE_CANNOT_INSERT_TS                82
       EXITCODE_SIGNATURE_REMOVAL_FAILED        83
       EXITCODE_SIGNATURE_UID_NOT_FOUND         84
       EXITCODE_SIGNATURE_CREATION_FAILED       85
       EXITCODE_SYNTAX_ERROR_IN_TAG_FILE        86
       EXITCODE_TS_CONSISTENCY_CHECK_FAILED     87

   application specific errors
       EXITCODE_NO_SIGNATURES_PRESENT           100
       EXITCODE_SIGNATURE_VERIFICATION_FAILED   101
       EXITCODE_SIGNATURE_VERIFICATION_POLICY   102

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  behavior  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)  2000-2025  by OFFIS e.V., Escherweg 2, 26121 Oldenburg,
       Germany.

Version 3.7.0                   Mon Dec 15 2025                     dcmsign(1)
