Representing Binary Data by Using Base 64 Encoding

Base 64 encoded data is represented by the :: symbol, as shown in this example:

jpegPhoto:: encoded_data

In addition to binary data, the following values must be base 64 encoded:

• Any value that begins with a semicolon, ;, or a space

• Any value that contains non ASCII data, including new lines

Use the ldif command with the -b parameter to convert binary data to LDIF format, as follows.

$ ldif -b attributeName

For more information about how to use the ldif command, see the ldif(1) man page.

In the above example, attributeName is the name of the attribute to which you are supplying the binary data. The binary data is read from standard input and the results are written to standard output. Use redirection operators to select input and output files.

The command takes any input and formats it with the correct line continuation and appropriate attribute information. The command also assesses whether the input requires base–64 encoding. The following example takes a binary file containing a JPEG image and converts it into LDIF format for the attribute named jpegPhoto. The output is saved to out.ldif:

$ ldif -b jpegPhoto < aphoto.jpg > out.ldif

The -b option specifies that the utility should interpret the entire input as a single binary value. If the -b option is not present, each line is considered as a separate input value.

You can edit the output file to add the LDIF statements required to create or modify the directory entry that will contain the binary value. For example, you can open the file out.ldif in a text editor and add the following lines at the top of the file.

dn: cn=Barbara Jensen,ou=People,dc=example,dc=com
changetype: modify
add: jpegPhoto
jpegPhoto:: encoded_data

In this example, encoded_data represents the contents of the out.ldif file produced by the command.