PES-Assignment-5

Code for Assign 5 for PRES, ECEN 5813-001B, Fall 2022

Function Call Tree

main()
 |
 *-----> time_pbkdf2_hmac_isha()
                   |
                   *-----> pbkdf2_hmac_isha()
                                 |
                                 *-----> F()
                                         | 
                                         *-----> hmac_isha()
                                                     |
                                                     *-----> ISHAReset()
                                                     |
                                                     *-----> ISHAInput()
                                                     |           |
                                                     |           *-----> ISHAProcessMessageBlock()
                                                     |
                                                     *-----> ISHAResult()
                                                                 |
                                                                 *-----> ISHAPadMessage()
                                                                               |
                                                                               *-----> ISHAProcessMessageBlock()

Entire Program

• Build Configuration : Release
• Optimization : -O0
• Target : Program flash action using PEMicro probes
• Total Size Before Optimization : 19708
• Total Size After Optimization : 15200
• Timing Test Before Optimization: 8752 ms
• Timing Test After Optimization : 3040 ms

pbkdf2_hmac_isha()

• Size Before Optimization: 0x00000108
• Size After Optimization: 0x00000108
• Changes:
  • None
• During time_pbkdf2_hmac_isha(), the function pbkdf2_hmac_isha() is invoked from 1 separate line:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
1	8752 ms : 0 ms	3040 ms : 0 ms	time_pbkdf2_hmac_isha	Unconditional

F()

• Size Before Optimization: 0x000001b8
• Size After Optimization: 0x00000134
• Changes:
  • Defined iterator i as register storage
  • Used same iterator i in all loops (other than loop using iterator j) rather than having each loop declare its own iterator i
• During time_pbkdf2_hmac_isha(), the function F() is invoked from 1 separate line:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
3	8752 ms : 362 ms	3040 ms : 137 ms	pbkdf2_hmac_isha	For int i=0; i<l; i++

hmac_isha()

• Size Before Optimization: 0x00000184
• Size After Optimization: 0x000000c2
• Changes:
  • Removed if(key_len > ISHA_BLOCKLEN) conditional since code does not ever go into this branch. This introduces limitation of catching case where key_len > ISHA_BLOCKLEN
  • Combined for(i=0; i<key_len; i++) and for(i=key_len; i<ISHA_BLOCKLEN; i++) loops and added a conditional within loop itself
  • Combined both for(i=0; i<ISHA_BLOCKLEN; i++) loops
  • Removed keypad array and assigned directly to ipad + opad
  • Defined iterator i as register storage
• During time_pbkdf2_hmac_isha(), the function hmac_isha() is invoked from 2 separate lines:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
3	2 ms : 0 ms	0 ms : 0 ms	F	Unconditional
12285	8461 ms : 1428 ms	2916 ms : 363 ms	F	For int j=1; j<iter; j++

ISHAReset()

• Size Before Optimization: 0x00000060
• Size After Optimization: 0x00000054
• Changes:
  • Removed ctx->corrupted flag
  • Removed logic for Length_High/Length_Low bits and replaced with Length_Bytes
• During time_pbkdf2_hmac_isha(), the function ISHAReset() is invoked from 3 separate lines:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
0	0 ms : 0 ms	N/A	hmac_isha	If key_len > ISHA_BLOCKLEN
12288	28 ms : 28 ms	26 ms : 26 ms	hmac_isha	Inner ISHA
12288	28 ms : 28 ms	26 ms : 26 ms	hmac_isha	Outer ISHA

ISHAInput()

• Size Before Optimization: 0x000000ae
• Size After Optimization: 0x000000c8
• Changes:
  • Stored length into register iterator i and replaced all instances of length with iterator i
  • Removed ctx->corrupted flag
  • Incremented message_length in-line
  • Removed logic for Length_High/Length_Low bits and replaced with Length_Bytes
  • Improved loop to go 1 byte at a time to 64 bytes at a time. Also utilized memcpy to achieve this
• During time_pbkdf2_hmac_isha(), the function ISHAInput() is invoked from 5 separate lines:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
0	0 ms : 0 ms	N/A	hmac_isha	If key_len > ISHA_BLOCKLEN
12288	1996 ms : 1250 ms	57 ms : 66 ms	hmac_isha	Inner ISHA - ipad
12288	417 ms : 399 ms	459 ms : 74 ms	hmac_isha	Inner ISHA - msg
12288	2000 ms : 1249 ms	65 ms : 66 ms	hmac_isha	Outer ISHA - opad
12288	417 ms : 409 ms	467 ms : 74 ms	hmac_isha	Outer ISHA - inner_digest

ISHAResult()

• Size Before Optimization: 0x000000c0
• Size After Optimization: 0x00000096
• Changes:
  • Replaced all instances of (i/4) with (t >> 2)
  • Removed ctx->corrupted flag
• During time_pbkdf2_hmac_isha(), the function ISHAResult() is invoked from 3 separate lines:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
0	0 ms : 0 ms	N/A	hmac_isha	If key_len > ISHA_BLOCKLEN
12288	1089 ms : 148 ms	740 ms : 129 ms	hmac_isha	Inner ISHA
12288	1089 ms : 148 ms	740 ms : 128 ms	hmac_isha	Outer ISHA

ISHAPadMessage()

• Size Before Optimization: 0x0000010e
• Size After Optimization: 0x000000e6
• Changes:
  • Removed while(ctx->MB_Idx < 56) loops out of if/else and put it after since it is unconditional
  • Removed logic for Length_High/Length_Low bits and replaced with Length_Bytes. This introduces limitation of not supporting message length over 0xFFFFFFFF bytes
• During time_pbkdf2_hmac_isha(), the function ISHAPadMessage() is invoked from 1 separate line:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
24576	1902 ms : 472 ms	1250 ms : 476 ms	ISHAResult	If !ctx->Computed

ISHAProcessMessageBlock

• Size Before Optimization: 0x00000152
• Size After Optimization: 0x000000e6
• Changes:
  • Replaced all instances of (t * 4) with (t << 2)
  • Combined both for(t = 0; t < 16; t++) loops
  • Defined iterator t as register storage
  • Removed W array and assigned directly into temp. This may decrease readability but increases performance
• During time_pbkdf2_hmac_isha(), the function ISHAProcessMessageBlock() is invoked from 3 separate lines:

Count	Total Time Before Optimization (Deep : Surface)	Total Time After Optimization (Deep : Surface)	Caller	Invocation Details
24576	1404 ms : 1404 ms	818 ms : 853 ms	ISHAInput	If ctx->MB_Idx == 64
0	0 ms : 0 ms	0 ms : 0 ms	ISHAPadMessage	If ctx->MB_Idx > 55
24576	1462 ms : 1462 ms	769 ms : 769 ms	ISHAPadMessage	Unconditional