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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
commitb5896ba9f6047e7031e2bdee0622d543e11a6734 (patch)
treefd7b460593a2fee1be579bec5697e6d887ea3421 /src/tls/tls_prng_exch.c
parentInitial commit. (diff)
downloadpostfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.tar.xz
postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.zip
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--src/tls/tls_prng_exch.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/src/tls/tls_prng_exch.c b/src/tls/tls_prng_exch.c
new file mode 100644
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+++ b/src/tls/tls_prng_exch.c
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+/*++
+/* NAME
+/* tls_prng_exch 3
+/* SUMMARY
+/* maintain PRNG exchange file
+/* SYNOPSIS
+/* #include <tls_prng_src.h>
+/*
+/* TLS_PRNG_SRC *tls_prng_exch_open(name, timeout)
+/* const char *name;
+/* int timeout;
+/*
+/* void tls_prng_exch_update(fh, length)
+/* TLS_PRNG_SRC *fh;
+/* size_t length;
+/*
+/* void tls_prng_exch_close(fh)
+/* TLS_PRNG_SRC *fh;
+/* DESCRIPTION
+/* tls_prng_exch_open() opens the specified PRNG exchange file
+/* and returns a handle that should be used with all subsequent
+/* access.
+/*
+/* tls_prng_exch_update() reads the requested number of bytes
+/* from the PRNG exchange file, updates the OpenSSL PRNG, and
+/* writes the requested number of bytes to the exchange file.
+/* The file is locked for exclusive access.
+/*
+/* tls_prng_exch_close() closes the specified PRNG exchange
+/* file and releases memory that was allocated for the handle.
+/*
+/* Arguments:
+/* .IP name
+/* The name of the PRNG exchange file.
+/* .IP length
+/* The number of bytes to read from/write to the entropy file.
+/* .IP timeout
+/* Time limit on individual I/O operations.
+/* DIAGNOSTICS
+/* All errors are fatal.
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+
+/* OpenSSL library. */
+
+#ifdef USE_TLS
+#include <openssl/rand.h> /* For the PRNG */
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <iostuff.h>
+#include <myflock.h>
+
+/* TLS library. */
+
+#include <tls_prng.h>
+
+/* Application specific. */
+
+#define TLS_PRNG_EXCH_SIZE 1024 /* XXX Why not configurable? */
+
+/* tls_prng_exch_open - open PRNG exchange file */
+
+TLS_PRNG_SRC *tls_prng_exch_open(const char *name)
+{
+ const char *myname = "tls_prng_exch_open";
+ TLS_PRNG_SRC *eh;
+ int fd;
+
+ if ((fd = open(name, O_RDWR | O_CREAT, 0600)) < 0)
+ msg_fatal("%s: cannot open PRNG exchange file %s: %m", myname, name);
+ eh = (TLS_PRNG_SRC *) mymalloc(sizeof(*eh));
+ eh->fd = fd;
+ eh->name = mystrdup(name);
+ eh->timeout = 0;
+ if (msg_verbose)
+ msg_info("%s: opened PRNG exchange file %s", myname, name);
+ return (eh);
+}
+
+/* tls_prng_exch_update - update PRNG exchange file */
+
+void tls_prng_exch_update(TLS_PRNG_SRC *eh)
+{
+ unsigned char buffer[TLS_PRNG_EXCH_SIZE];
+ ssize_t count;
+
+ /*
+ * Update the PRNG exchange file. Since other processes may have added
+ * entropy, we use a read-stir-write cycle.
+ */
+ if (myflock(eh->fd, INTERNAL_LOCK, MYFLOCK_OP_EXCLUSIVE) != 0)
+ msg_fatal("cannot lock PRNG exchange file %s: %m", eh->name);
+ if (lseek(eh->fd, 0, SEEK_SET) < 0)
+ msg_fatal("cannot seek PRNG exchange file %s: %m", eh->name);
+ if ((count = read(eh->fd, buffer, sizeof(buffer))) < 0)
+ msg_fatal("cannot read PRNG exchange file %s: %m", eh->name);
+
+ if (count > 0)
+ RAND_seed(buffer, count);
+ RAND_bytes(buffer, sizeof(buffer));
+
+ if (lseek(eh->fd, 0, SEEK_SET) < 0)
+ msg_fatal("cannot seek PRNG exchange file %s: %m", eh->name);
+ if (write(eh->fd, buffer, sizeof(buffer)) != sizeof(buffer))
+ msg_fatal("cannot write PRNG exchange file %s: %m", eh->name);
+ if (myflock(eh->fd, INTERNAL_LOCK, MYFLOCK_OP_NONE) != 0)
+ msg_fatal("cannot unlock PRNG exchange file %s: %m", eh->name);
+}
+
+/* tls_prng_exch_close - close PRNG exchange file */
+
+void tls_prng_exch_close(TLS_PRNG_SRC *eh)
+{
+ const char *myname = "tls_prng_exch_close";
+
+ if (close(eh->fd) < 0)
+ msg_fatal("close PRNG exchange file %s: %m", eh->name);
+ if (msg_verbose)
+ msg_info("%s: closed PRNG exchange file %s", myname, eh->name);
+ myfree(eh->name);
+ myfree((void *) eh);
+}
+
+#endif