# SVC_SHA1GetHash

## Syntax

      #include <twl/os/common/systemCall.h>

      void SVC_SHA1GetHash( SVCSHA1Context *context,
      void* md );

## Arguments

context | Pointer to the context structure used for SHA-1 generation.
md | Pointer to the memory location that holds the message digest value.

## Return Values

None.

## Description

Gets the digest value using SHA-1.

Use the `SVC_SHA1Init` function to initialize the context argument and then use the `SVC_SHA1Update` function to provide the input data.

The length of the generated message digest value is 160 bits, or `SVC_SHA1_DIGEST_SIZE` (= 20) bytes. Use the md argument to pass an area that can store a value of this size.

This function rewrites context internally, so you cannot continue to use the same context with the `SVC_SHA1Update` function.

SHA-1 is an algorithm to find the message digest value. For details, see RFC (Request For Comments) 3174, which is published by IETF (the Internet Engineering Task Force).

## See Also

`SVC_SHA1Init`
`SVC_SHA1Update`

## Revision History

2007/10/22 Changed the order of the arguments.
2007/10/19 Initial version.

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