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Computer Security Exam Jul 14, 2015 First name: ________________________ Last name: ________________________ Matricola: ________________________ Signature: ________________________ Homeworks? [ ] (Y) [ ] (N) Instructions ● The exam is composed of 8 pages. ● Just as a cross check, tell us whether you have completed the homeworks, by putting an "X" mark appropriately. ● The exam is "closed books". Please put away in a non­suspicious place (i.e. not below the desk) any note, book, or similar. You will be expelled if, at any time, if you do not follow this rule. ● You are not allowed to communicate with other students, and you will be expelled from the exam if you do. ● Shut down and store electronic devices. They will be subject to inspection if found and you may be expelled if you are found using one. ● Please answer within the allowed space. Schemes are good, short answers are recommended. ● You can write in pen or pencil, any color, but ​avoid writing in red​. ● No extra paper is allowed. ● The answers ​must be written exclusively in the space provided​ below the questions. PROPOSED SOLUTION 1 of 8 Question 1 (4 points) Consider the following assembly code: function_prologue: pushl $0x0000d00d pushl %ebp mov %esp,%ebp subl $4, %esp function_foo: (function body) function_epilogue: movl %ebp, %esp popl %ebp cmpl $0x0000d00d,(%esp) jne function_bar addl $4,%esp ret function_bar: (function body) 1) (2 points) Describe in detail what the assembly code does and the name of the technique that is being implemented. This is a canary implementation. ​pushl $0x0000d00d ​pushes a static value on the stack. At the epilogue, the value is checked by ​cmpl $0x0000d00d,(%esp) ​and if it has been changed execution is diverted to function_bar. Otherwise the function returns normally. 2)…