Freescale Semiconductor MPC8313E PowerQUICC II Pro Family Reference Manual page 673

Bits Name
58 SMAC Specifies whether to perform an SSL-MAC operation
0 Normal operation
1 Perform an SSL3.0 MAC operation. This requires a key and key length. If this is set then the HMAC bit
should be 0.
59 INIT Initialization bit. Most operations will require this bit to be set. Cleared only for operations that load context
from a known intermediate hash value.
0 Do not initialize digest registers. In this case the registers must be loaded from a hash context pointer in
the descriptor. When the data to be hashed is spread across multiple descriptors, this bit is set on all but
the first descriptor.
1 Do an algorithm-specific initialization of the digest registers.
60 HMAC Specifies whether to perform an HMAC operation
0 Normal operation
1 Perform an HMAC operation. This requires a key and key length. If this is set then the SMAC bit should
be 0.
61 EALG The EALG (Extended Algorithm bit) and ALG (Algorithm) bits together specify the message digest
algorithm, as follows:
62–63 ALG
000 SHA-160 algorithm (full name for SHA-1)
001 SHA-256 algorithm
010 MD5 algorithm
011 SHA-224 algorithm
Others: Reserved
14.4.2.2 Recommended Settings for MDEUMR
The most common task likely to be executed through the MDEU is HMAC generation. HMACs are used
to provide message integrity within a number of security protocols, including IPSec, and TLS. The SSL
3.0 protocol uses a slightly different 'SSL-MAC'. If an HMAC or SSL-MAC is to be performed using a
single descriptor (with the MDEU acting as sole or secondary EU), the following mode register bit settings
should be used:
Table 14-19. Mode Register—HMAC or SSL-MAC Generated by Single Descriptor
To generate an HMAC for a message that is spread across a sequence of descriptors, the following mode
register bit settings should be used:
MPC8313E PowerQUICC™ II Pro Integrated Processor Family Reference Manual, Rev. 2
Freescale Semiconductor
Table 14-18. MDEUMR in 'New' Configuration (continued)
Bits Field
56 CONT
58 SMAC
59 INIT
60 HMAC
Description
Value
For HMAC For SSL-MAC
0 (off) 0 (off)
0 (on) 1(on)
1(on) 1(on)
1 (on) 0 (on)
Security Engine (SEC) 2.2
14-31