--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/source/fitz/random.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,111 @@
+// Copyright (C) 2004-2021 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF 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 Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+#include "mupdf/fitz.h"
+
+/* The pseudo-random number generator in this file is based on the MIT licensed
+ * implementation in musl libc. */
+
+#include <string.h>
+
+/* The seed is initialized in context.c as follows:
+ * static uint16_t __seed48[7] = { 0, 0, 0, 0xe66d, 0xdeec, 0x5, 0xb };
+ */
+
+static uint64_t fz_rand48_step(uint16_t *xi, uint16_t *lc)
+{
+	uint64_t a, x;
+	x = xi[0] | (xi[1]+0U)<<16 | (xi[2]+0ULL)<<32;
+	a = lc[0] | (lc[1]+0U)<<16 | (lc[2]+0ULL)<<32;
+	x = a*x + lc[3];
+	xi[0] = x;
+	xi[1] = x>>16;
+	xi[2] = x>>32;
+	return x & 0xffffffffffffull;
+}
+
+double fz_erand48(fz_context *ctx, uint16_t s[3])
+{
+	union {
+		uint64_t u;
+		double f;
+	} x = { 0x3ff0000000000000ULL | fz_rand48_step(s, ctx->seed48+3)<<4 };
+	return x.f - 1.0;
+}
+
+/*
+	Pseudo-random numbers using a linear congruential algorithm and 48-bit
+	integer arithmetic.
+*/
+double fz_drand48(fz_context *ctx)
+{
+	return fz_erand48(ctx, ctx->seed48);
+}
+
+int32_t fz_nrand48(fz_context *ctx, uint16_t s[3])
+{
+	return fz_rand48_step(s, ctx->seed48+3) >> 17;
+}
+
+int32_t fz_lrand48(fz_context *ctx)
+{
+	return fz_nrand48(ctx, ctx->seed48);
+}
+
+int32_t fz_jrand48(fz_context *ctx, uint16_t s[3])
+{
+	return (int32_t)(fz_rand48_step(s, ctx->seed48+3) >> 16);
+}
+
+int32_t fz_mrand48(fz_context *ctx)
+{
+	return fz_jrand48(ctx, ctx->seed48);
+}
+
+void fz_lcong48(fz_context *ctx, uint16_t p[7])
+{
+	memcpy(ctx->seed48, p, sizeof ctx->seed48);
+}
+
+uint16_t *fz_seed48(fz_context *ctx, uint16_t *s)
+{
+	static uint16_t p[3];
+	memcpy(p, ctx->seed48, sizeof p);
+	memcpy(ctx->seed48, s, sizeof p);
+	return p;
+}
+
+void fz_srand48(fz_context *ctx, int32_t seed)
+{
+	uint16_t p[3] = { 0x330e, seed, seed>>16 };
+	fz_seed48(ctx, p);
+}
+
+void fz_memrnd(fz_context *ctx, unsigned char *data, int len)
+{
+#ifdef CLUSTER
+	memset(data, 0x55, len);
+#else
+	while (len-- > 0)
+		*data++ = (unsigned char)fz_lrand48(ctx);
+#endif
+}