Source data: ${var}
Value of context variable named "var":  a String type: "fred"
Input characters: 4 characters: { f, r, e, d }
Chars converted to bytes using UTF-8:  4 bytes: { 66, 72, 65, 64 }
MD5 hash of these 4 bytes: 16 bytes: { 57, 0a, 90, bf, bf, 8c, 7e, ab, 5d, c5, d4, e2, 68, 32, d5, b1 }
Base-64 encoding of MD5 hash 16 bytes: "VwqQv7+MfqtdxdTiaDLVsQ=="

Source data: ${var}
Value of context variable named "var":  a String type: "fr?d"
Input characters: 4 characters: { f, r, ?, d }
Chars converted to bytes using UTF-8:  5 bytes: { 66, 72, c3, aa, 64 }
MD5 hash of these 5 bytes: 16 bytes: { 4e, bb, c0, c6, f7, 12, f6, 86, 97, 56, 9e, 99, 03, 9e, b0, 65 }
Base-64 encoding of MD5 hash 16 bytes: "TrvAxvcS9oaXVp6ZA56wZQ=="

Source data: ${var}
Value of context variable named "var":  a Message type: application/octet-stream: containing 6 body bytes: { 2E, 00, FF, 1F, 7E, 01 }
Input bytes: 6 bytes: { 2e, 00, ff, 1f, 7e, 01 }
MD5 hash of these 6 bytes: 16 bytes: { 0b, 93, 3c, df, f1, df, 80, 04, f5, f8, 4e, 75, e8, 51, 7c, 11 }
Base-64 encoding of MD5 hash 16 bytes: "C5M83/HfgAT1+E516FF8EQ=="

Do one of the following:
To add the assertion to the Policy Development window, see Add an Assertion.
To change the configuration of an existing assertion, proceed to step 2 below.
This assertion contains default settings that are appropriate for most instances. To change any of the settings, right-click 
Generate Security Hash
 in the policy window and select
 Generate Security Hash
 or double-click the assertion in the policy window. The assertion properties are displayed. 
Configure the properties as follows:
Setting	Description
Source Data	Enter the data that will have the Signature Algorithm applied to it. You may enter text or specify a context variable. You may also enter an expression that combines static text with context variables.
Save line breaks as	Select the line break option for the source data entered above: CR LF (carriage return, line feed), LF (line feed), CR (carriage return). The default is CR LF .
Output Variable	Enter the name of the context variable that will hold the generated signature. TECHNICAL NOTE: Output values The output value is:      Base64( Hash( Input ) )  if using a non-keyed hash (such as MD5, SHA-1, etc.)      Base64( HMAC( Key, Input ) )  if using keyed hash (such as HMAC-SHA1, HMAC-SHA256, etc.) Where:   - Key is the key value bytes (with strings converted to bytes using UTF-8)   - Input is the input value bytes (with strings converted to bytes using UTF-8)   - Hash/HMAC is the selected transformation (MD5, SHA-1, HMAC-SHA256, etc.)   - Base64 is the "encode bytes as Base-64" operation Note the following: To obtain the raw binary value of the hash, use the Encode/Decode Data Assertion to decode the Base64-encoded hash. To obtain a hex encoded version of the value, use the Encode/Decode Data Assertion to Base64-decode it to Message data type, then Base16-encode it to String.
Signature Algorithm	Choose the algorithm to use from the drop-down list:  HMAC-MD5HMAC-SHA1 HMAC-SHA256 HMAC-SHA384 HMAC-SHA512 MD5 SHA-1 SHA-256 SHA-384 SHA-512 Note the following: Choosing a HMAC algorithm will cause the assertion to produce a HMAC digest with the selected algorithm applied to the Source Data and Key . Choosing a non-HMAC algorithm will cause the assertion to produce a generic digest with the selected algorithm applied to the Source Data . Avoid non-HMAC algorithms, as they produce weak hashing that can be exploited.
Key (Enabled only for HMAC signature algorithms)	Enter the key that will be used to generate the hash when a HMAC algorithm is selected. You may enter text or specify a context variable. You may also enter an expression that combines static text with context variables. For text keys, type it directly into this field. For Base64 and hexadecimal keys, you must first use the Encode/Decode Data Assertion to decode from Base64/hex to binary. (In the policy, it is presented as a message with application/octet-stream.) The resulting context variable from the Encode/Decode Data assertion is placed in this Key field. For any other type of binary key, first set it as a context variable of type 'Message', then enter that variable in this Key field. Observe the following tips about the key: Keep the key in a secure location. Never transmit the key over the network for any reason. If you suspect the key has been compromised, regenerate a new key and rebuild the policy. Longer keys produce a stronger hash.
Click [
OK
] when done.