Annotated edit history of
SUID version 3 showing authors affecting page license.
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CraigBox |
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A [SUID] program (short for Set [UID]) is when a program has the <tt>u+s</tt> permission bit set. This means that the program runs with the Effective UID (EUID|UID] of the person that owns the file, not the person that runs the program. For instance, a SUID program owned by <tt>root</tt> would run as <tt>root</tt>, instead of a normal user when executed. |
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To run a progam completely as a new user, it needs to be SUID to that user, and you need to execute |
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<verbatim> |
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setregid( getegid(), getegid() ); |
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setreuid( geteuid(), getegid() ); |
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</verbatim> |
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Many progams need this, as they will drop any [EUID|UID] permissions on startup. You can do so using: |
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<verbatim> |
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setregid( getgid(), getgid() ); |
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setreuid( getuid(), getuid() ); |
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</verbatim> |
