--- /dev/null
+/* Functions to compute MD5 message digest of files or memory blocks.
+ according to the definition of MD5 in RFC 1321 from April 1992.
+ Copyright (C) 1995-2023 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/>. */
+
+/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
+
+#include <string.h>
+#include <endian.h>
+#include "md5.h"
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+# define WORDS_BIGENDIAN 1
+#endif
+
+#ifdef WORDS_BIGENDIAN
+# define SWAP(n) \
+ (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+#else
+# define SWAP(n) (n)
+#endif
+
+
+/* This array contains the bytes used to pad the buffer to the next
+ 64-byte boundary. (RFC 1321, 3.1: Step 1) */
+static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
+
+
+/* Initialize structure containing state of computation.
+ (RFC 1321, 3.3: Step 3) */
+void
+__md5_init_ctx (struct md5_ctx *ctx)
+{
+ ctx->A = 0x67452301;
+ ctx->B = 0xefcdab89;
+ ctx->C = 0x98badcfe;
+ ctx->D = 0x10325476;
+
+ ctx->total[0] = ctx->total[1] = 0;
+ ctx->buflen = 0;
+}
+
+/* Put result from CTX in first 16 bytes following RESBUF. The result
+ must be in little endian byte order.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32 bits value. */
+void *
+__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
+{
+ ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
+ ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
+ ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
+ ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
+
+ return resbuf;
+}
+
+/* Process the remaining bytes in the internal buffer and the usual
+ prolog according to the standard and write the result to RESBUF.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32 bits value. */
+void *
+__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
+{
+ /* Take yet unprocessed bytes into account. */
+ md5_uint32 bytes = ctx->buflen;
+ size_t pad;
+
+ /* Now count remaining bytes. */
+ ctx->total[0] += bytes;
+ if (ctx->total[0] < bytes)
+ ++ctx->total[1];
+
+ 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] = SWAP (ctx->total[0] << 3);
+ ctx->buffer32[(bytes + pad + 4) / 4] = SWAP ((ctx->total[1] << 3)
+ | (ctx->total[0] >> 29));
+
+ /* Process last bytes. */
+ __md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
+
+ return __md5_read_ctx (ctx, resbuf);
+}
+
+/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
+ result is always in little endian byte order, so that a byte-wise
+ output yields to the wanted ASCII representation of the message
+ digest. */
+void *
+__md5_buffer (const char *buffer, size_t len, void *resblock)
+{
+ struct md5_ctx ctx;
+
+ /* Initialize the computation context. */
+ __md5_init_ctx (&ctx);
+
+ /* Process whole buffer but last len % 64 bytes. */
+ __md5_process_bytes (buffer, len, &ctx);
+
+ /* Put result in desired memory area. */
+ return __md5_finish_ctx (&ctx, resblock);
+}
+
+
+void
+__md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *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)
+ {
+ __md5_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)
+ {
+ while (len > 64)
+ {
+ __md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+ buffer = (const char *) buffer + 64;
+ len -= 64;
+ }
+ }
+
+ /* Move remaining bytes in 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)
+ {
+ __md5_process_block (ctx->buffer, 64, ctx);
+ left_over -= 64;
+ memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+ }
+ ctx->buflen = left_over;
+ }
+}
+
+#include <md5-block.c>
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