--- /dev/null
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * SHA-256 algorithm
+ *
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <byteswap.h>
+#include <assert.h>
+#include <ipxe/rotate.h>
+#include <ipxe/crypto.h>
+#include <ipxe/asn1.h>
+#include <ipxe/sha256.h>
+
+/** SHA-256 variables */
+struct sha256_variables {
+ /* This layout matches that of struct sha256_digest_data,
+ * allowing for efficient endianness-conversion,
+ */
+ uint32_t a;
+ uint32_t b;
+ uint32_t c;
+ uint32_t d;
+ uint32_t e;
+ uint32_t f;
+ uint32_t g;
+ uint32_t h;
+ uint32_t w[64];
+} __attribute__ (( packed ));
+
+/** SHA-256 constants */
+static const uint32_t k[64] = {
+ 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
+};
+
+/**
+ * Initialise SHA-256 algorithm
+ *
+ * @v ctx SHA-256 context
+ */
+static void sha256_init ( void *ctx ) {
+ struct sha256_context *context = ctx;
+
+ context->ddd.dd.digest.h[0] = cpu_to_be32 ( 0x6a09e667 );
+ context->ddd.dd.digest.h[1] = cpu_to_be32 ( 0xbb67ae85 );
+ context->ddd.dd.digest.h[2] = cpu_to_be32 ( 0x3c6ef372 );
+ context->ddd.dd.digest.h[3] = cpu_to_be32 ( 0xa54ff53a );
+ context->ddd.dd.digest.h[4] = cpu_to_be32 ( 0x510e527f );
+ context->ddd.dd.digest.h[5] = cpu_to_be32 ( 0x9b05688c );
+ context->ddd.dd.digest.h[6] = cpu_to_be32 ( 0x1f83d9ab );
+ context->ddd.dd.digest.h[7] = cpu_to_be32 ( 0x5be0cd19 );
+ context->len = 0;
+}
+
+/**
+ * Calculate SHA-256 digest of accumulated data
+ *
+ * @v context SHA-256 context
+ */
+static void sha256_digest ( struct sha256_context *context ) {
+ 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 );
+ linker_assert ( &u.ddd.dd.digest.h[0] == a, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[1] == b, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[2] == c, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[3] == d, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[4] == e, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[5] == f, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[6] == g, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.digest.h[7] == h, sha256_bad_layout );
+ linker_assert ( &u.ddd.dd.data.dword[0] == w, sha256_bad_layout );
+
+ 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 < 64 ; 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 < 64 ; 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 ) );
+}
+
+/**
+ * Accumulate data with SHA-256 algorithm
+ *
+ * @v ctx SHA-256 context
+ * @v data Data
+ * @v len Length of data
+ */
+static void sha256_update ( void *ctx, const void *data, size_t len ) {
+ 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 );
+ }
+}
+
+/**
+ * Generate SHA-256 digest
+ *
+ * @v ctx SHA-256 context
+ * @v out Output buffer
+ */
+static void sha256_final ( void *ctx, void *out ) {
+ 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,
+ sizeof ( context->ddd.dd.digest ) );
+}
+
+/** SHA-256 algorithm */
+struct digest_algorithm sha256_algorithm = {
+ .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,
+};
+
+/** "sha256" object identifier */
+static uint8_t oid_sha256[] = { ASN1_OID_SHA256 };
+
+/** "sha256" OID-identified algorithm */
+struct asn1_algorithm oid_sha256_algorithm __asn1_algorithm = {
+ .name = "sha256",
+ .digest = &sha256_algorithm,
+ .oid = ASN1_OID_CURSOR ( oid_sha256 ),
+};
Code Review / kvmfornfv.git / blobdiff