Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 285 insertions, 0 deletions

diff --git a/src/fundamental/sha256.c b/src/fundamental/sha256.c
new file mode 100644
index 0000000..4389e9e
--- /dev/null
+++ b/src/fundamental/sha256.c
@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+/* Stolen from glibc and converted to our style. In glibc it comes with the following copyright blurb: */
+
+/* Functions to compute SHA256 message digest of files or memory blocks.
+   according to the definition of SHA256 in FIPS 180-2.
+   Copyright (C) 2007-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdbool.h>
+#if SD_BOOT
+#  include "efi-string.h"
+#else
+#  include <string.h>
+#endif
+
+#include "macro-fundamental.h"
+#include "sha256.h"
+#include "unaligned-fundamental.h"
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+# define SWAP(n)                                                        \
+        (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+# define SWAP64(n)                              \
+        (((n) << 56)                            \
+         | (((n) & 0xff00) << 40)               \
+         | (((n) & 0xff0000) << 24)             \
+         | (((n) & 0xff000000) << 8)            \
+         | (((n) >> 8) & 0xff000000)            \
+         | (((n) >> 24) & 0xff0000)             \
+         | (((n) >> 40) & 0xff00)               \
+         | ((n) >> 56))
+#else
+# define SWAP(n) (n)
+# define SWAP64(n) (n)
+#endif
+
+/* This array contains the bytes used to pad the buffer to the next
+   64-byte boundary.  (FIPS 180-2:5.1.1)  */
+static const uint8_t fillbuf[64] = {
+        0x80, 0 /* , 0, 0, ...  */
+};
+
+/* Constants for SHA256 from FIPS 180-2:4.2.2.  */
+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
+};
+
+static void sha256_process_block(const void *, size_t, struct sha256_ctx *);
+
+/* Initialize structure containing state of computation.
+   (FIPS 180-2:5.3.2)  */
+void sha256_init_ctx(struct sha256_ctx *ctx) {
+        assert(ctx);
+
+        ctx->H[0] = 0x6a09e667;
+        ctx->H[1] = 0xbb67ae85;
+        ctx->H[2] = 0x3c6ef372;
+        ctx->H[3] = 0xa54ff53a;
+        ctx->H[4] = 0x510e527f;
+        ctx->H[5] = 0x9b05688c;
+        ctx->H[6] = 0x1f83d9ab;
+        ctx->H[7] = 0x5be0cd19;
+
+        ctx->total64 = 0;
+        ctx->buflen = 0;
+}
+
+/* Process the remaining bytes in the internal buffer and the usual
+   prolog according to the standard and write the result to RESBUF. */
+uint8_t *sha256_finish_ctx(struct sha256_ctx *ctx, uint8_t resbuf[static SHA256_DIGEST_SIZE]) {
+        /* Take yet unprocessed bytes into account.  */
+        uint32_t bytes = ctx->buflen;
+        size_t pad;
+
+        assert(ctx);
+        assert(resbuf);
+
+        /* Now count remaining bytes.  */
+        ctx->total64 += bytes;
+
+        pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
+        memcpy(&ctx->buffer[bytes], fillbuf, pad);
+
+        /* Put the 64-bit file length in *bits* at the end of the buffer.  */
+        ctx->buffer32[(bytes + pad + 4) / 4] = SWAP(ctx->total[TOTAL64_low] << 3);
+        ctx->buffer32[(bytes + pad) / 4] = SWAP((ctx->total[TOTAL64_high] << 3)
+                                                | (ctx->total[TOTAL64_low] >> 29));
+
+        /* Process last bytes.  */
+        sha256_process_block(ctx->buffer, bytes + pad + 8, ctx);
+
+        /* Put result from CTX in first 32 bytes following RESBUF.  */
+        for (size_t i = 0; i < 8; ++i)
+                unaligned_write_ne32(resbuf + i * sizeof(uint32_t), SWAP(ctx->H[i]));
+        return resbuf;
+}
+
+void sha256_process_bytes(const void *buffer, size_t len, struct sha256_ctx *ctx) {
+        assert(buffer);
+        assert(ctx);
+
+        /* When we already have some bits in our internal buffer concatenate
+           both inputs first.  */
+
+        if (ctx->buflen != 0) {
+                size_t left_over = ctx->buflen;
+                size_t add = 128 - left_over > len ? len : 128 - left_over;
+
+                memcpy(&ctx->buffer[left_over], buffer, add);
+                ctx->buflen += add;
+
+                if (ctx->buflen > 64) {
+                        sha256_process_block(ctx->buffer, ctx->buflen & ~63, ctx);
+
+                        ctx->buflen &= 63;
+                        /* The regions in the following copy operation cannot overlap.  */
+                        memcpy(ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+                                ctx->buflen);
+                }
+
+                buffer = (const char *) buffer + add;
+                len -= add;
+        }
+
+        /* Process available complete blocks.  */
+        if (len >= 64) {
+                if (IS_ALIGNED32(buffer)) {
+                        sha256_process_block(buffer, len & ~63, ctx);
+                        buffer = (const char *) buffer + (len & ~63);
+                        len &= 63;
+                } else
+                        while (len > 64) {
+                                memcpy(ctx->buffer, buffer, 64);
+                                sha256_process_block(ctx->buffer, 64, ctx);
+                                buffer = (const char *) buffer + 64;
+                                len -= 64;
+                        }
+        }
+
+        /* Move remaining bytes into internal buffer.  */
+        if (len > 0) {
+                size_t left_over = ctx->buflen;
+
+                memcpy(&ctx->buffer[left_over], buffer, len);
+                left_over += len;
+                if (left_over >= 64) {
+                        sha256_process_block(ctx->buffer, 64, ctx);
+                        left_over -= 64;
+                        memcpy(ctx->buffer, &ctx->buffer[64], left_over);
+                }
+                ctx->buflen = left_over;
+        }
+}
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+   It is assumed that LEN % 64 == 0.  */
+static void sha256_process_block(const void *buffer, size_t len, struct sha256_ctx *ctx) {
+        const uint32_t *words = ASSERT_PTR(buffer);
+        size_t nwords = len / sizeof(uint32_t);
+
+        assert(ctx);
+
+        uint32_t a = ctx->H[0];
+        uint32_t b = ctx->H[1];
+        uint32_t c = ctx->H[2];
+        uint32_t d = ctx->H[3];
+        uint32_t e = ctx->H[4];
+        uint32_t f = ctx->H[5];
+        uint32_t g = ctx->H[6];
+        uint32_t h = ctx->H[7];
+
+        /* First increment the byte count.  FIPS 180-2 specifies the possible
+           length of the file up to 2^64 bits.  Here we only compute the
+           number of bytes.  */
+        ctx->total64 += len;
+
+        /* Process all bytes in the buffer with 64 bytes in each round of
+           the loop.  */
+        while (nwords > 0) {
+                uint32_t W[64];
+                uint32_t a_save = a;
+                uint32_t b_save = b;
+                uint32_t c_save = c;
+                uint32_t d_save = d;
+                uint32_t e_save = e;
+                uint32_t f_save = f;
+                uint32_t g_save = g;
+                uint32_t h_save = h;
+
+                /* Operators defined in FIPS 180-2:4.1.2.  */
+#define Ch(x, y, z) ((x & y) ^ (~x & z))
+#define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
+#define S0(x) (CYCLIC (x, 2) ^ CYCLIC (x, 13) ^ CYCLIC (x, 22))
+#define S1(x) (CYCLIC (x, 6) ^ CYCLIC (x, 11) ^ CYCLIC (x, 25))
+#define R0(x) (CYCLIC (x, 7) ^ CYCLIC (x, 18) ^ (x >> 3))
+#define R1(x) (CYCLIC (x, 17) ^ CYCLIC (x, 19) ^ (x >> 10))
+
+                /* It is unfortunate that C does not provide an operator for
+                   cyclic rotation.  Hope the C compiler is smart enough.  */
+#define CYCLIC(w, s) ((w >> s) | (w << (32 - s)))
+
+                /* Compute the message schedule according to FIPS 180-2:6.2.2 step 2.  */
+                for (size_t t = 0; t < 16; ++t) {
+                        W[t] = SWAP (*words);
+                        ++words;
+                }
+                for (size_t t = 16; t < 64; ++t)
+                        W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
+
+                /* The actual computation according to FIPS 180-2:6.2.2 step 3.  */
+                for (size_t t = 0; t < 64; ++t) {
+                        uint32_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
+                        uint32_t T2 = S0 (a) + Maj (a, b, c);
+                        h = g;
+                        g = f;
+                        f = e;
+                        e = d + T1;
+                        d = c;
+                        c = b;
+                        b = a;
+                        a = T1 + T2;
+                }
+
+                /* Add the starting values of the context according to FIPS 180-2:6.2.2
+                   step 4.  */
+                a += a_save;
+                b += b_save;
+                c += c_save;
+                d += d_save;
+                e += e_save;
+                f += f_save;
+                g += g_save;
+                h += h_save;
+
+                /* Prepare for the next round.  */
+                nwords -= 16;
+        }
+
+        /* Put checksum in context given as argument.  */
+        ctx->H[0] = a;
+        ctx->H[1] = b;
+        ctx->H[2] = c;
+        ctx->H[3] = d;
+        ctx->H[4] = e;
+        ctx->H[5] = f;
+        ctx->H[6] = g;
+        ctx->H[7] = h;
+}
+
+uint8_t* sha256_direct(const void *buffer, size_t sz, uint8_t result[static SHA256_DIGEST_SIZE]) {
+        struct sha256_ctx ctx;
+        sha256_init_ctx(&ctx);
+        sha256_process_bytes(buffer, sz, &ctx);
+        return sha256_finish_ctx(&ctx, result);
+}