SHA-256 algorithm. More...

#include <stdint.h>
#include <string.h>
#include <byteswap.h>
#include <assert.h>
#include <ipxe/rotate.h>
#include <ipxe/crypto.h>
#include <ipxe/sha256.h>

Data Structures
struct	sha256_variables
	SHA-256 variables. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)

void	sha256_family_init (struct sha256_context context, const struct sha256_digest init, size_t digestsize)
	Initialise SHA-256 family algorithm. More...

static void	sha256_init (void *ctx)
	Initialise SHA-256 algorithm. More...

static void	sha256_digest (struct sha256_context *context)
	Calculate SHA-256 digest of accumulated data. More...

void	sha256_update (void ctx, const void data, size_t len)
	Accumulate data with SHA-256 algorithm. More...

void	sha256_final (void ctx, void out)
	Generate SHA-256 digest. More...

Variables
static const uint32_t	k [SHA256_ROUNDS]
	SHA-256 constants. More...

static const struct sha256_digest	sha256_init_digest
	SHA-256 initial digest values. More...

struct digest_algorithm	sha256_algorithm
	SHA-256 algorithm. More...

Detailed Description

SHA-256 algorithm.

Definition in file sha256.c.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )

◆ sha256_family_init()

void sha256_family_init	(	struct sha256_context *	context,
		const struct sha256_digest *	init,
		size_t	digestsize
	)

Initialise SHA-256 family algorithm.

Parameters

context	SHA-256 context
init	Initial digest values
digestsize	Digest size

Definition at line 92 of file sha256.c.

                                               {
 
         context->len = 0;
         context->digestsize = digestsize;
         memcpy ( &context->ddd.dd.digest, init,
                  sizeof ( context->ddd.dd.digest ) );
 }

References sha256_digest_data_dwords::dd, sha256_context::ddd, sha256_digest_data::digest, digestsize, sha256_context::digestsize, sha256_context::len, and memcpy().

Referenced by sha224_init(), and sha256_init().

◆ sha256_init()

static void sha256_init ( void * ctx )

static

Initialise SHA-256 algorithm.

Parameters

ctx	SHA-256 context

Definition at line 107 of file sha256.c.

                                       {
         struct sha256_context *context = ctx;
 
         sha256_family_init ( context, &sha256_init_digest,
                              sizeof ( struct sha256_digest ) );
 }

References ctx, sha256_family_init(), and sha256_init_digest.

◆ sha256_digest()

static void sha256_digest ( struct sha256_context * context )

static

Calculate SHA-256 digest of accumulated data.

Parameters

context SHA-256 context

Definition at line 119 of file sha256.c.

                                                              {
         union {
                 union sha256_digest_data_dwords ddd;
                 struct sha256_variables v;
         } u;
         uint32_t *a = &u.v.a;
         uint32_t *b = &u.v.b;
         uint32_t *c = &u.v.c;
         uint32_t *d = &u.v.d;
         uint32_t *e = &u.v.e;
         uint32_t *f = &u.v.f;
         uint32_t *g = &u.v.g;
         uint32_t *h = &u.v.h;
         uint32_t *w = u.v.w;
         uint32_t s0;
         uint32_t s1;
         uint32_t maj;
         uint32_t t1;
         uint32_t t2;
         uint32_t ch;
         unsigned int i;
 
         /* Sanity checks */
         assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
         build_assert ( &u.ddd.dd.digest.h[0] == a );
         build_assert ( &u.ddd.dd.digest.h[1] == b );
         build_assert ( &u.ddd.dd.digest.h[2] == c );
         build_assert ( &u.ddd.dd.digest.h[3] == d );
         build_assert ( &u.ddd.dd.digest.h[4] == e );
         build_assert ( &u.ddd.dd.digest.h[5] == f );
         build_assert ( &u.ddd.dd.digest.h[6] == g );
         build_assert ( &u.ddd.dd.digest.h[7] == h );
         build_assert ( &u.ddd.dd.data.dword[0] == w );
 
         DBGC ( context, "SHA256 digesting:\n" );
         DBGC_HDA ( context, 0, &context->ddd.dd.digest,
                    sizeof ( context->ddd.dd.digest ) );
         DBGC_HDA ( context, context->len, &context->ddd.dd.data,
                    sizeof ( context->ddd.dd.data ) );
 
         /* Convert h[0..7] to host-endian, and initialise a, b, c, d,
          * e, f, g, h, and w[0..15]
          */
         for ( i = 0 ; i < ( sizeof ( u.ddd.dword ) /
                             sizeof ( u.ddd.dword[0] ) ) ; i++ ) {
                 be32_to_cpus ( &context->ddd.dword[i] );
                 u.ddd.dword[i] = context->ddd.dword[i];
         }
 
         /* Initialise w[16..63] */
         for ( i = 16 ; i < SHA256_ROUNDS ; i++ ) {
                 s0 = ( ror32 ( w[i-15], 7 ) ^ ror32 ( w[i-15], 18 ) ^
                        ( w[i-15] >> 3 ) );
                 s1 = ( ror32 ( w[i-2], 17 ) ^ ror32 ( w[i-2], 19 ) ^
                        ( w[i-2] >> 10 ) );
                 w[i] = ( w[i-16] + s0 + w[i-7] + s1 );
         }
 
         /* Main loop */
         for ( i = 0 ; i < SHA256_ROUNDS ; i++ ) {
                 s0 = ( ror32 ( *a, 2 ) ^ ror32 ( *a, 13 ) ^ ror32 ( *a, 22 ) );
                 maj = ( ( *a & *b ) ^ ( *a & *c ) ^ ( *b & *c ) );
                 t2 = ( s0 + maj );
                 s1 = ( ror32 ( *e, 6 ) ^ ror32 ( *e, 11 ) ^ ror32 ( *e, 25 ) );
                 ch = ( ( *e & *f ) ^ ( (~*e) & *g ) );
                 t1 = ( *h + s1 + ch + k[i] + w[i] );
                 *h = *g;
                 *g = *f;
                 *f = *e;
                 *e = ( *d + t1 );
                 *d = *c;
                 *c = *b;
                 *b = *a;
                 *a = ( t1 + t2 );
                 DBGC2 ( context, "%2d : %08x %08x %08x %08x %08x %08x %08x "
                         "%08x\n", i, *a, *b, *c, *d, *e, *f, *g, *h );
         }
 
         /* Add chunk to hash and convert back to big-endian */
         for ( i = 0 ; i < 8 ; i++ ) {
                 context->ddd.dd.digest.h[i] =
                         cpu_to_be32 ( context->ddd.dd.digest.h[i] +
                                       u.ddd.dd.digest.h[i] );
         }
 
         DBGC ( context, "SHA256 digested:\n" );
         DBGC_HDA ( context, 0, &context->ddd.dd.digest,
                    sizeof ( context->ddd.dd.digest ) );
 }

References sha256_variables::a, assert(), sha256_variables::b, be32_to_cpus, build_assert, sha256_variables::c, ch, cpu_to_be32, sha256_variables::d, sha256_digest_data::data, DBGC, DBGC2, DBGC_HDA, sha256_digest_data_dwords::dd, sha256_context::ddd, sha256_digest_data::digest, sha256_digest_data_dwords::dword, sha256_variables::e, sha256_variables::f, sha256_variables::g, h, sha256_digest::h, k, sha256_context::len, ror32(), SHA256_ROUNDS, u, and sha256_variables::w.

Referenced by sha256_update().

◆ sha256_update()

void sha256_update	(	void *	ctx,
		const void *	data,
		size_t	len
	)

Accumulate data with SHA-256 algorithm.

Parameters

ctx	SHA-256 context
data	Data
len	Length of data

Definition at line 216 of file sha256.c.

                                                                {
         struct sha256_context *context = ctx;
         const uint8_t *byte = data;
         size_t offset;
 
         /* Accumulate data a byte at a time, performing the digest
          * whenever we fill the data buffer
          */
         while ( len-- ) {
                 offset = ( context->len % sizeof ( context->ddd.dd.data ) );
                 context->ddd.dd.data.byte[offset] = *(byte++);
                 context->len++;
                 if ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 )
                         sha256_digest ( context );
         }
 }

References sha256_block::byte, ctx, data, sha256_digest_data::data, sha256_digest_data_dwords::dd, sha256_context::ddd, sha256_context::len, len, offset, and sha256_digest().

Referenced by sha256_final().

◆ sha256_final()

void sha256_final	(	void *	ctx,
		void *	out
	)

Generate SHA-256 digest.

Parameters

ctx	SHA-256 context
out	Output buffer

Definition at line 239 of file sha256.c.

                                            {
         struct sha256_context *context = ctx;
         uint64_t len_bits;
         uint8_t pad;
 
         /* Record length before pre-processing */
         len_bits = cpu_to_be64 ( ( ( uint64_t ) context->len ) * 8 );
 
         /* Pad with a single "1" bit followed by as many "0" bits as required */
         pad = 0x80;
         do {
                 sha256_update ( ctx, &pad, sizeof ( pad ) );
                 pad = 0x00;
         } while ( ( context->len % sizeof ( context->ddd.dd.data ) ) !=
                   offsetof ( typeof ( context->ddd.dd.data ), final.len ) );
 
         /* Append length (in bits) */
         sha256_update ( ctx, &len_bits, sizeof ( len_bits ) );
         assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
 
         /* Copy out final digest */
         memcpy ( out, &context->ddd.dd.digest, context->digestsize );
 }

References assert(), cpu_to_be64, ctx, sha256_digest_data::data, sha256_digest_data_dwords::dd, sha256_context::ddd, sha256_digest_data::digest, sha256_context::digestsize, sha256_context::len, memcpy(), offsetof, out, pad, sha256_update(), and typeof().

Variable Documentation

◆ k

const uint32_t k[SHA256_ROUNDS]

static

Initial value:

= {
        0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
        0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
        0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
        0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
        0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
        0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
        0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
        0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
        0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
        0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
        0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
}

SHA-256 constants.

Definition at line 57 of file sha256.c.

Referenced by sha256_digest().

◆ sha256_init_digest

const struct sha256_digest sha256_init_digest

static

Initial value:

= {
        .h = {
                cpu_to_be32 ( 0x6a09e667 ),
                cpu_to_be32 ( 0xbb67ae85 ),
                cpu_to_be32 ( 0x3c6ef372 ),
                cpu_to_be32 ( 0xa54ff53a ),
                cpu_to_be32 ( 0x510e527f ),
                cpu_to_be32 ( 0x9b05688c ),
                cpu_to_be32 ( 0x1f83d9ab ),
                cpu_to_be32 ( 0x5be0cd19 ),
        },
}

SHA-256 initial digest values.

Definition at line 72 of file sha256.c.

Referenced by sha256_init().

◆ sha256_algorithm

struct digest_algorithm sha256_algorithm

Initial value:

= {
        .name           = "sha256",
        .ctxsize        = sizeof ( struct sha256_context ),
        .blocksize      = sizeof ( union sha256_block ),
        .digestsize     = sizeof ( struct sha256_digest ),
        .init           = sha256_init,
        .update         = sha256_update,
        .final          = sha256_final,
}

SHA-256 algorithm.

Definition at line 264 of file sha256.c.

Referenced by icert_cert(), peerdist_info_v1(), sha256_test_exec(), and sha256sum_exec().

Data Structures

Functions

Variables

Detailed Description

Function Documentation

◆ FILE_LICENCE()

◆ sha256_family_init()

◆ sha256_init()

◆ sha256_digest()

◆ sha256_update()

◆ sha256_final()

Variable Documentation

◆ k

◆ sha256_init_digest

◆ sha256_algorithm