SHA3(3)                    Library Functions Manual                    SHA3(3)

NAME
     SHA3 - NIST FIPS PUB 202: SHA-3 Standard: Permutation-Based Hash and
     Extendable-Output Functions

LIBRARY
     Message Digest (MD4, MD5, etc.) Support Library (libmd, -lmd)

SYNOPSIS
     #include <sha3.h>

     void
     SHA3_224_Init(SHA3_224_CTX *ctx);

     void
     SHA3_224_Update(SHA3_224_CTX *ctx, const uint8_t *buf, size_t len);

     void
     SHA3_224_Final(uint8_t digest[SHA3_224_DIGEST_LENGTH],
         SHA3_224_CTX *ctx);

     void
     SHA3_256_Init(SHA3_256_CTX *ctx);

     void
     SHA3_256_Update(SHA3_256_CTX *ctx, const uint8_t *buf, size_t len);

     void
     SHA3_256_Final(uint8_t digest[SHA3_256_DIGEST_LENGTH],
         SHA3_256_CTX *ctx);

     void
     SHA3_384_Init(SHA3_384_CTX *ctx);

     void
     SHA3_384_Update(SHA3_384_CTX *ctx, const uint8_t *buf, size_t len);

     void
     SHA3_384_Final(uint8_t digest[SHA3_384_DIGEST_LENGTH],
         SHA3_384_CTX *ctx);

     void
     SHA3_512_Init(SHA3_512_CTX *ctx);

     void
     SHA3_512_Update(SHA3_512_CTX *ctx, const uint8_t *buf, size_t len);

     void
     SHA3_512_Final(uint8_t digest[SHA3_512_DIGEST_LENGTH],
         SHA3_512_CTX *ctx);

DESCRIPTION
     The SHA3 functions implement the cryptographic hash functions of the NIST
     SHA-3 standard, FIPS PUB 202.  The SHA3 functions compress an arbitrary-
     length message m into short fixed-length octet strings SHA3-224(m),
     SHA3-256(m), etc., called a cryptographic digest or hash.

     Before using the SHA3 functions, applications should first call
     SHA3_Selftest(3) and confirm that it succeeded.

     Only the SHA3_256 functions are specified in detail; the SHA3_224,
     SHA3_384, and SHA3_512 functions are exactly analogous.

     The caller must allocate memory for a SHA3_256_CTX object to hold the
     state of a SHA3-256 hash computation over a message.  SHA3_256_CTX
     objects are slightly over 200 bytes, and may be copied or relocated in
     memory.

     SHA3_256_Init(ctx)
           Initialize a SHA3-256 context.  Must be done before any other
           operations on ctx.

     SHA3_256_Update(ctx, data, len)
           Append len octets at data to the message.

     SHA3_256_Final(digest, ctx)
           Store at digest the 32-octet SHA3-256 hash of the message obtained
           by concatenating all prior inputs to SHA3_256_Update() on ctx.

           Subsequent use of ctx is not allowed, unless it is reinitialized
           with SHA3_256_Init().

SEE ALSO
     SHA3_Selftest(3), shake(3)

STANDARDS
     National Institute of Standards and Technology, SHA-3 Standard:
     Permutation-Based Hash and Extendable-Output Functions, August 2015, FIPS
     PUB 202.

AUTHORS
     Taylor R Campbell <campbell+sha3@mumble.net>

Linux 7.0.3-arch1-2            October 14, 2015            Linux 7.0.3-arch1-2