1 files changed, 192 insertions, 0 deletions
diff --git a/lib/md2.c b/lib/md2.c
new file mode 100644
index 0000000..8ca535c
--- /dev/null
+++ b/lib/md2.c
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+/* Functions to compute MD2 message digest of files or memory blocks.
+   according to the definition of MD2 in RFC 1319 from April 1992.
+   Copyright (C) 1995-1997, 1999-2003, 2005-2006, 2008-2022 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/>.  */
+
+/* Adapted by Simon Josefsson from public domain Libtomcrypt 1.06 by
+   Tom St Denis. */
+
+#include <config.h>
+
+/* Specification.  */
+#include "md2.h"
+
+#include <string.h>
+#include <sys/types.h>
+
+#include <minmax.h>
+
+static void md2_update_chksum (struct md2_ctx *md);
+static void md2_compress (struct md2_ctx *md);
+
+/* Initialize structure containing state of computation.
+   (RFC 1319, 3.3: Step 3)  */
+void
+md2_init_ctx (struct md2_ctx *ctx)
+{
+  memset (ctx->X, 0, sizeof (ctx->X));
+  memset (ctx->chksum, 0, sizeof (ctx->chksum));
+  memset (ctx->buf, 0, sizeof (ctx->buf));
+  ctx->curlen = 0;
+}
+
+/* Put result from CTX in first 16 bytes following RESBUF.  The result
+   must be in little endian byte order.  */
+void *
+md2_read_ctx (const struct md2_ctx *ctx, void *resbuf)
+{
+  memcpy (resbuf, ctx->X, 16);
+
+  return resbuf;
+}
+
+/* Process the remaining bytes in the internal buffer and the usual
+   prolog according to the standard and write the result to RESBUF.  */
+void *
+md2_finish_ctx (struct md2_ctx *ctx, void *resbuf)
+{
+  unsigned long i, k;
+
+  /* pad the message */
+  k = 16 - ctx->curlen;
+  for (i = ctx->curlen; i < 16; i++)
+    {
+      ctx->buf[i] = (unsigned char) k;
+    }
+
+  /* hash and update */
+  md2_compress (ctx);
+  md2_update_chksum (ctx);
+
+  /* hash checksum */
+  memcpy (ctx->buf, ctx->chksum, 16);
+  md2_compress (ctx);
+
+  return md2_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 *
+md2_buffer (const char *buffer, size_t len, void *resblock)
+{
+  struct md2_ctx ctx;
+
+  /* Initialize the computation context.  */
+  md2_init_ctx (&ctx);
+
+  /* Process whole buffer but last len % 64 bytes.  */
+  md2_process_block (buffer, len, &ctx);
+
+  /* Put result in desired memory area.  */
+  return md2_finish_ctx (&ctx, resblock);
+}
+
+void
+md2_process_bytes (const void *buffer, size_t len, struct md2_ctx *ctx)
+{
+  const char *in = buffer;
+  unsigned long n;
+
+  while (len > 0)
+    {
+      n = MIN (len, (16 - ctx->curlen));
+      memcpy (ctx->buf + ctx->curlen, in, (size_t) n);
+      ctx->curlen += n;
+      in += n;
+      len -= n;
+
+      /* is 16 bytes full? */
+      if (ctx->curlen == 16)
+        {
+          md2_compress (ctx);
+          md2_update_chksum (ctx);
+          ctx->curlen = 0;
+        }
+    }
+}
+
+static const unsigned char PI_SUBST[256] = {
+  41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
+  19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
+  76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
+  138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
+  245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
+  148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
+  39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
+  181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
+  150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
+  112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
+  96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
+  85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
+  234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
+  129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
+  8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
+  203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
+  166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
+  31, 26, 219, 153, 141, 51, 159, 17, 131, 20
+};
+
+/* adds 16 bytes to the checksum */
+static void
+md2_update_chksum (struct md2_ctx *ctx)
+{
+  int j;
+  unsigned char L;
+
+  L = ctx->chksum[15];
+  for (j = 0; j < 16; j++)
+    {
+      /* caution, the RFC says its "C[j] = S[M[i*16+j] xor L]" but the
+         reference source code [and test vectors] say otherwise. */
+      L = (ctx->chksum[j] ^= PI_SUBST[(int) (ctx->buf[j] ^ L)] & 255);
+    }
+}
+
+static void
+md2_compress (struct md2_ctx *ctx)
+{
+  size_t j, k;
+  unsigned char t;
+
+  /* copy block */
+  for (j = 0; j < 16; j++)
+    {
+      ctx->X[16 + j] = ctx->buf[j];
+      ctx->X[32 + j] = ctx->X[j] ^ ctx->X[16 + j];
+    }
+
+  t = (unsigned char) 0;
+
+  /* do 18 rounds */
+  for (j = 0; j < 18; j++)
+    {
+      for (k = 0; k < 48; k++)
+        {
+          t = (ctx->X[k] ^= PI_SUBST[(int) (t & 255)]);
+        }
+      t = (t + (unsigned char) j) & 255;
+    }
+}
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.  */
+void
+md2_process_block (const void *buffer, size_t len, struct md2_ctx *ctx)
+{
+  md2_process_bytes (buffer, len, ctx);
+}