gnupg: Specify a User ID

 
 7 How to Specify a User Id
 **************************
 
 There are different ways to specify a user ID to GnuPG. Some of them are
 only valid for 'gpg' others are only good for 'gpgsm'.  Here is the
 entire list of ways to specify a key:
 
    * By key Id.  This format is deduced from the length of the string
      and its content or '0x' prefix.  The key Id of an X.509 certificate
      are the low 64 bits of its SHA-1 fingerprint.  The use of key Ids
      is just a shortcut, for all automated processing the fingerprint
      should be used.
 
      When using 'gpg' an exclamation mark (!)  may be appended to force
      using the specified primary or secondary key and not to try and
      calculate which primary or secondary key to use.
 
      The last four lines of the example give the key ID in their long
      form as internally used by the OpenPGP protocol.  You can see the
      long key ID using the option '--with-colons'.
 
           234567C4
           0F34E556E
           01347A56A
           0xAB123456
 
           234AABBCC34567C4
           0F323456784E56EAB
           01AB3FED1347A5612
           0x234AABBCC34567C4
 
    * By fingerprint.  This format is deduced from the length of the
      string and its content or the '0x' prefix.  Note, that only the 20
      byte version fingerprint is available with 'gpgsm' (i.e.  the SHA-1
      hash of the certificate).
 
      When using 'gpg' an exclamation mark (!)  may be appended to force
      using the specified primary or secondary key and not to try and
      calculate which primary or secondary key to use.
 
      The best way to specify a key Id is by using the fingerprint.  This
      avoids any ambiguities in case that there are duplicated key IDs.
 
           1234343434343434C434343434343434
           123434343434343C3434343434343734349A3434
           0E12343434343434343434EAB3484343434343434
           0xE12343434343434343434EAB3484343434343434
 
      'gpgsm' also accepts colons between each pair of hexadecimal digits
      because this is the de-facto standard on how to present X.509
      fingerprints.  'gpg' also allows the use of the space separated
      SHA-1 fingerprint as printed by the key listing commands.
 
    * By exact match on OpenPGP user ID. This is denoted by a leading
      equal sign.  It does not make sense for X.509 certificates.
 
           =Heinrich Heine <heinrichh@uni-duesseldorf.de>
 
    * By exact match on an email address.  This is indicated by enclosing
      the email address in the usual way with left and right angles.
 
           <heinrichh@uni-duesseldorf.de>
 
    * By partial match on an email address.  This is indicated by
      prefixing the search string with an '@'.  This uses a substring
      search but considers only the mail address (i.e.  inside the angle
      brackets).
 
           @heinrichh
 
    * By exact match on the subject's DN. This is indicated by a leading
      slash, directly followed by the RFC-2253 encoded DN of the subject.
      Note that you can't use the string printed by 'gpgsm --list-keys'
      because that one has been reordered and modified for better
      readability; use '--with-colons' to print the raw (but standard
      escaped) RFC-2253 string.
 
           /CN=Heinrich Heine,O=Poets,L=Paris,C=FR
 
    * By exact match on the issuer's DN. This is indicated by a leading
      hash mark, directly followed by a slash and then directly followed
      by the RFC-2253 encoded DN of the issuer.  This should return the
      Root cert of the issuer.  See note above.
 
           #/CN=Root Cert,O=Poets,L=Paris,C=FR
 
    * By exact match on serial number and issuer's DN. This is indicated
      by a hash mark, followed by the hexadecimal representation of the
      serial number, then followed by a slash and the RFC-2253 encoded DN
      of the issuer.  See note above.
 
           #4F03/CN=Root Cert,O=Poets,L=Paris,C=FR
 
    * By keygrip.  This is indicated by an ampersand followed by the 40
      hex digits of a keygrip.  'gpgsm' prints the keygrip when using the
      command '--dump-cert'.
 
           &D75F22C3F86E355877348498CDC92BD21010A480
 
    * By substring match.  This is the default mode but applications may
      want to explicitly indicate this by putting the asterisk in front.
      Match is not case sensitive.
 
           Heine
           *Heine
 
    * .  and + prefixes These prefixes are reserved for looking up mails
      anchored at the end and for a word search mode.  They are not yet
      implemented and using them is undefined.
 
    Please note that we have reused the hash mark identifier which was
 used in old GnuPG versions to indicate the so called local-id.  It is
 not anymore used and there should be no conflict when used with X.509
 stuff.
 
    Using the RFC-2253 format of DNs has the drawback that it is not
 possible to map them back to the original encoding, however we don't
 have to do this because our key database stores this encoding as meta
 data.