--- /dev/null
+/* sha3-stream.c - Functions to compute the SHA-3 message digest of files as
+ specified by FIPS-202.
+
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+ This file 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.
+
+ This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "sha3.h"
+
+#include <stdlib.h>
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+#include "af_alg.h"
+
+#define BLOCKSIZE 31824
+#if (BLOCKSIZE % 144 != 0 && BLOCKSIZE % 136 != 0 && BLOCKSIZE % 104 != 0 \
+ && BLOCKSIZE % 72 != 0)
+# error "invalid BLOCKSIZE"
+#endif
+
+/* Compute message digest for bytes read from STREAM using algorithm ALG.
+ Write the message digest into RESBLOCK, which contains HASHLEN bytes.
+ The initial operation is INIT_CTX. Return zero if and only if
+ successful. */
+static int
+sha3_xxx_stream (FILE *stream, char const *alg, void *resblock,
+ ssize_t hashlen, void (*init_ctx) (struct sha3_ctx *))
+{
+ switch (afalg_stream (stream, alg, resblock, hashlen))
+ {
+ case 0: return 0;
+ case -EIO: return 1;
+ }
+
+ char *buffer = malloc (BLOCKSIZE + 72);
+ if (!buffer)
+ return 1;
+
+ struct sha3_ctx ctx;
+ init_ctx (&ctx);
+ size_t sum;
+
+ /* Iterate over full file contents. */
+ while (1)
+ {
+ /* We read the file in blocks of BLOCKSIZE bytes. One call of the
+ computation function processes the whole buffer so that with the
+ next round of the loop another block can be read. */
+ size_t n;
+ sum = 0;
+
+ /* Read block. Take care for partial reads. */
+ while (1)
+ {
+ /* Either process a partial fread() from this loop,
+ or the fread() in afalg_stream may have gotten EOF.
+ We need to avoid a subsequent fread() as EOF may
+ not be sticky. For details of such systems, see:
+ https://sourceware.org/PR1190 */
+ if (feof (stream))
+ goto process_partial_block;
+
+ n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
+
+ sum += n;
+
+ if (sum == BLOCKSIZE)
+ break;
+
+ if (n == 0)
+ {
+ /* Check for the error flag IFF N == 0, so that we don't
+ exit the loop after a partial read due to e.g., EAGAIN
+ or EWOULDBLOCK. */
+ if (ferror (stream))
+ {
+ free (buffer);
+ return 1;
+ }
+ goto process_partial_block;
+ }
+ }
+
+ /* Process buffer with BLOCKSIZE bytes. Note that
+ BLOCKSIZE % ctx.blocklen == 0
+ */
+ sha3_process_block (buffer, BLOCKSIZE, &ctx);
+ }
+
+ process_partial_block:;
+
+ /* Process any remaining bytes. */
+ if (sum > 0)
+ sha3_process_bytes (buffer, sum, &ctx);
+
+ /* Construct result in desired memory. */
+ sha3_finish_ctx (&ctx, resblock);
+ free (buffer);
+ return 0;
+}
+
+int
+sha3_224_stream (FILE *stream, void *resblock)
+{
+ return sha3_xxx_stream (stream, "sha3-224", resblock, SHA3_224_DIGEST_SIZE,
+ sha3_224_init_ctx);
+}
+
+int
+sha3_256_stream (FILE *stream, void *resblock)
+{
+ return sha3_xxx_stream (stream, "sha3-256", resblock, SHA3_256_DIGEST_SIZE,
+ sha3_256_init_ctx);
+}
+
+int
+sha3_384_stream (FILE *stream, void *resblock)
+{
+ return sha3_xxx_stream (stream, "sha3-384", resblock, SHA3_384_DIGEST_SIZE,
+ sha3_384_init_ctx);
+}
+
+int
+sha3_512_stream (FILE *stream, void *resblock)
+{
+ return sha3_xxx_stream (stream, "sha3-512", resblock, SHA3_512_DIGEST_SIZE,
+ sha3_512_init_ctx);
+}
extern void *sha3_512_buffer (const char *buffer, size_t len,
void *restrict resblock);
+/* Compute SHA-3 message digest for bytes read from STREAM. STREAM is an open
+ file stream. Regular files are handled more efficiently. The contents of
+ STREAM from its current position to its end will be read. The case that the
+ last operation on STREAM was an 'ungetc' is not supported. The resulting
+ message digest number will be written into RESBLOCK. */
+extern int sha3_224_stream (FILE *stream, void *resblock);
+extern int sha3_256_stream (FILE *stream, void *resblock);
+extern int sha3_384_stream (FILE *stream, void *resblock);
+extern int sha3_512_stream (FILE *stream, void *resblock);
+
# ifdef __cplusplus
}
# endif
projects / thirdparty / gnulib.git / commitdiff
