Secure Key Exchange over an Insecure Medium with Public Key Cryptography - Implementing SSL/TLS Using Cryptography and PKI - page 104

the algorithms illustrated here don't work at all if the huge presented includes
extraneous leading zeros. And, of course, you have to deal with little-endian/
big-endian conversion. You can accomplish this as shown in Listing 3-11.

h1

h2 tmp

0 1 0 1 01 1 0 1 0 1 1 00 1 1 1 0 1 1 00 1 1

h2 & 0 × 01

0 1 0 1 01 1 0 1 0 1 1 0 01 1 0 +

h2 & 0 × 02

0 1 0 1 01 1 0 10 1 1 0 0 11 0 0 10 1 1 0 0 11 0 0

+

h2 & 0 × 04

0 1 0 1 01 1 0 11 0 1 0 0 1 10 0 0 11 0 1 0 0 1 10 0 0

h2 & 0 × 08

0 1 0 1 01 1 0 1 0 1 1 0 0 1 1 00 0 0 +

h2 & 0 10

×

0 1 0 1 01 1 0 1 0 1 1 0 0 1 1 0 00 0 0 1 0 1 10 0 1 1 0 00 0 0

h2 & 0 × 20

0 1 0 1 01 1 0 1 0 1 1 00 1 1 0 0 00 0 0 +

h2 & 0 × 40

0 1 0 1 01 1 0 1 0 1 1 00 1 1 0 0 0 00 0 0 1 0 1 1 00 1 1 0 0 0 00 0 0

h2 & 0 × 80

0 1 0 1 01 1 0 1 0 1 1 00 1 1 0 0 0 0 00 0 0

Figure 3-3: Large number multiplication