HMAC Hex Key Ambiguity

This issue arises frequently.

Service providers often give instructions for HMAC generation using a hexadecimal HMAC key, such as:

01A0251D601FEF3305A38B124068A001CF3F099AA187DB2886314C67CDFDEBCD

This creates ambiguity because the instructions can be interpreted in two ways:

1. The HMAC key consists of the ASCII byte values of '0', '1', 'A', '0', '2', '5', etc. (e.g., 0x30, 0x31, 0x41, etc.).
2. The HMAC key consists of the byte values represented by the hex string (e.g., 0x01, 0xA0, 0x25, etc.).

Chilkat supports both methods:

• For interpretation #1: use crypt.SetMacKeyString("01A0251D … 67CDFDEBCD")
• For interpretation #2: use crypt.SetMacKeyEncoded("01A0251D … 67CDFDEBCD", "hex")