RFC 3174 (rfc3174) - Page 2 of 22

US Secure Hash Algorithm 1 (SHA1)

RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001


Table of Contents

   1. Overview of Contents...........................................  2
   2. Definitions of Bit Strings and Integers........................  3
   3. Operations on Words............................................  3
   4. Message Padding................................................  4
   5. Functions and Constants Used...................................  6
   6. Computing the Message Digest...................................  6
   6.1 Method 1......................................................  6
   6.2 Method 2......................................................  7
   7. C Code.........................................................  8
   7.1 .h file.......................................................  8
   7.2 .c file....................................................... 10
   7.3 Test Driver................................................... 18
   8. Security Considerations........................................ 20
   References........................................................ 21
   Authors' Addresses................................................ 21
   Full Copyright Statement.......................................... 22

1. Overview of Contents

   NOTE: The text below is mostly taken from [FIPS 180-1] and assertions
   therein of the security of SHA-1 are made by the US Government, the
   author of [FIPS 180-1], and not by the authors of this document.

   This document specifies a Secure Hash Algorithm, SHA-1, for computing
   a condensed representation of a message or a data file.  When a
   message of any length