#
  # <public>
  proc isPgpSignature { value } {
    set length [string length $value]

    if {$length == 0 || ([string first [string trim {
      -----BEGIN PGP SIGNATURE-----
    }] $value] == 0 && [string first [subst [string trim {
      -----END PGP SIGNATURE-----\r\n
    }]] $value] == ($length - 29))} then {
      return true
    } else {
      return false
    }
  }

  #