HMAC Generator / Tester Tool. Computes a Hash-based message authentication code (HMAC) using a secret key. A HMAC is a small set of data that helps authenticate the nature of message; it protects the integrity and the authenticity of the message. Feb 17, 2006 You have a number of choices as to how you create the hash key. You might elect to fire an INSERT trigger, or use a stored procedure to create the hash key once the values of interest have been obtained, or even to execute an UPDATE query that creates the hash keys and populates the hash column retroactively (so that you can apply this technique to tables that already contain millions of rows). HMAC Generator / Tester Tool. Computes a Hash-based message authentication code (HMAC) using a secret key. A HMAC is a small set of data that helps authenticate the nature of message; it protects the integrity and the authenticity of the message. MD5 Hash Generator This online tool allows you to generate the MD5 hash of any string. The MD5 hash can not be decrypted if the text you entered is complicated enough.

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APPLIES TO: SQL Server Azure SQL Database Azure Synapse Analytics (SQL DW) Parallel Data Warehouse

Returns the MD2, MD4, MD5, SHA, SHA1, or SHA2 hash of its input in SQL Server.

Syntax

Arguments

<algorithm>
Identifies the hashing algorithm to be used to hash the input. This is a required argument with no default. The single quotation marks are required. Beginning with SQL Server 2016 (13.x), all algorithms other than SHA2_256, and SHA2_512 are deprecated.

@input
Specifies a variable containing the data to be hashed. @input is varchar, nvarchar, or varbinary.

'input'
Specifies an expression that evaluates to a character or binary string to be hashed.

The output conforms to the algorithm standard: 128 bits (16 bytes) for MD2, MD4, and MD5; 160 bits (20 bytes) for SHA and SHA1; 256 bits (32 bytes) for SHA2_256, and 512 bits (64 bytes) for SHA2_512.

Applies to: SQL Server 2012 (11.x) and later

For SQL Server 2014 (12.x) and earlier, allowed input values are limited to 8000 bytes.

Return Value

varbinary (maximum 8000 bytes)

Remarks

Consider using CHECKSUM or BINARY_CHECKSUM as alternatives to compute a hash value.

The MD2, MD4, MD5, SHA, and SHA1 algorithms are deprecated starting with SQL Server 2016 (13.x). Use SHA2_256 or SHA2_512 instead. Older algorithms will continue working, but they will raise a deprecation event.

Examples

Return the hash of a variable

The following example returns the SHA2_256 hash of the nvarchar data stored in variable @HashThis.

Return the hash of a table column

The following example returns the SHA2_256 hash of the values in column c1 in the table Test1.

Here is the result set.

Syntax

Arguments

@input
Specifies a variable containing the data to be hashed. @input is varchar, nvarchar, or varbinary.

'input'
Specifies an expression that evaluates to a character or binary string to be hashed.

The output conforms to the algorithm standard: 128 bits (16 bytes) for MD2, MD4, and MD5; 160 bits (20 bytes) for SHA and SHA1; 256 bits (32 bytes) for SHA2_256, and 512 bits (64 bytes) for SHA2_512.

Applies to: SQL Server 2012 (11.x) and later

For SQL Server 2014 (12.x) and earlier, allowed input values are limited to 8000 bytes.

Return Value

varbinary (maximum 8000 bytes)

Remarks

Consider using CHECKSUM or BINARY_CHECKSUM as alternatives to compute a hash value.

Generate Hash Key C#

Examples

Return the hash of a variable

The following example returns the SHA2_256 hash of the nvarchar data stored in variable @HashThis.

Return the hash of a table column

Generate Hash Key Python

The following example returns the SHA2_256 hash of the values in column c1 in the table Test1.

Here is the result set.

Syntax

Arguments

Return Value

Remarks

Examples

Return the hash of a variable

Return the hash of a table column

See Also

Syntax

Arguments

Return Value

Remarks

Generate Hash Key C#

Examples

Return the hash of a variable

Return the hash of a table column

Generate Hash Key Python

See Also

Generate Hash From A Key