CF use of STATIC_CAST without NULL checks

[jphickey]

This issue was imported from the GSFC issue tracking system

Imported from: [GSFCCFS-1773] CF use of STATIC_CAST without NULL checks
Originally submitted by: Hickey, Joseph P. (GSFC-582.0)[VANTAGE SYSTEMS INC] on Tue Nov 16 14:05:37 2021

Original Description:
This issue was originally reported by IV&V, creating Jira issue to track its disposition and resolution.

There are 7 instances in the CFS CF App source code in which the PDU hedaer pointer 'ph' can be a NULL value from a prior function call, and then it is passed into the function STATIC_CAST() where it is eventually dereferenced without any checks.

These calls to STATIC_CAST() pass 'ph' to CF_HeaderSize() which dereferences the pointer.

cf_cfdp.c line 476
cf_cfdp.c line 616
cf_cfdp.c line 654
cf_cfdp.c line 695
cf_cfdp_r.c line 491
cf_cfdp_s.c line 125
cf_cfdp.c line 1277