8.8.5.3.1 Message Digest Example

Considering the following 512-bit message (example given in FIPS 180-2):

“61626380000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000018”

The message is written to memory in a Little Endian (LE) system architecture.

Table 8-11. 512-bit Message Memory Mapping
Memory Address	Address Offset / Byte Lane
Memory Address	0x7 / 63:56	0x6 / 55:48	0x5 / 47:40	0x4 / 39:32	0x3 / 31:24	0x2 / 23:16	0x1 / 15:8	0x0 / 7:0
0x000	00	00	00	00	80	63	62	61
0x008–0x030	00	00	00	00	00	00	00	00
0x038	18	00	00	00	00	00	00	00

The digest is stored at the memory location pointed at by the ICM_HASH pointer with a Region Offset.

Table 8-12. LE Resulting SHA-160 Message Digest Memory Mapping
Memory Address	Address Offset / Byte Lane
Memory Address	0x7 / 63:56	0x6 / 55:48	0x5 / 47:40	0x4 / 39:32	0x3 / 31:24	0x2 / 23:16	0x1 / 15:8	0x0 / 7:0
0x000	6a	81	06	47	36	3e	99	a9
0x008	6c	c2	50	78	71	25	3e	ba
0x010	–	–	–	–	9d	d8	d0	9c

Table 8-13. Resulting SHA-256 Message Digest Memory Mapping
Memory Address	Address Offset / Byte Lane
Memory Address	0x7 / 63:56	0x6 / 55:48	0x5 / 47:40	0x4 / 39:32	0x3 / 31:24	0x2 / 23:16	0x1 / 15:8	0x0 / 7:0
0x000	ea	cf	01	8f	bf	16	78	ba
0x008	23	22	ae	5d	de	40	41	41
0x010	9c	7a	17	96	a3	61	03	b0
0x018	ad	15	00	f2	61	ff	10	b4

Considering the following 1024-bit message (example given in FIPS 180-2):

“6162638000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000018”

The message is written to memory in a Little Endian (LE) system architecture.

Table 8-14. 1024 bits Message Memory Mapping
Memory Address	Address Offset / Byte Lane
Memory Address	0x7 / 63:56	0x6 / 55:48	0x5 / 47:40	0x4 / 39:32	0x3 / 31:24	0x2 / 23:16	0x1 / 15:8	0x0 / 7:0
0x000	00	00	00	00	80	63	62	61
0x008–0x070	00	00	00	00	00	00	00	00
0x078	18	00	00	00	00	00	00	00