diff options
Diffstat (limited to 'src/tls/tls_prng_file.c')
| -rw-r--r-- | src/tls/tls_prng_file.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/tls/tls_prng_file.c b/src/tls/tls_prng_file.c new file mode 100644 index 0000000..23865be --- /dev/null +++ b/src/tls/tls_prng_file.c @@ -0,0 +1,155 @@ +/*++ +/* NAME +/* tls_prng_file 3 +/* SUMMARY +/* seed OpenSSL PRNG from entropy file +/* SYNOPSIS +/* #include <tls_prng_src.h> +/* +/* TLS_PRNG_SRC *tls_prng_file_open(name, timeout) +/* const char *name; +/* int timeout; +/* +/* ssize_t tls_prng_file_read(fh, length) +/* TLS_PRNG_SRC *fh; +/* size_t length; +/* +/* int tls_prng_file_close(fh) +/* TLS_PRNG_SRC *fh; +/* DESCRIPTION +/* tls_prng_file_open() open the specified file and returns +/* a handle that should be used with all subsequent access. +/* +/* tls_prng_file_read() reads the requested number of bytes from +/* the entropy file and updates the OpenSSL PRNG. The file is not +/* locked for shared or exclusive access. +/* +/* tls_prng_file_close() closes the specified entropy file +/* and releases memory that was allocated for the handle. +/* +/* Arguments: +/* .IP name +/* The pathname of the entropy file. +/* .IP length +/* The number of bytes to read from the entropy file. +/* .IP timeout +/* Time limit on individual I/O operations. +/* DIAGNOSTICS +/* tls_prng_file_open() returns a null pointer on error. +/* +/* tls_prng_file_read() returns -1 on error, the number +/* of bytes received on success. +/* +/* tls_prng_file_close() returns -1 on error, 0 on success. +/* +/* In all cases the errno variable indicates the type of error. +/* 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> +#include <errno.h> + +/* OpenSSL library. */ + +#ifdef USE_TLS +#include <openssl/rand.h> /* For the PRNG */ + +/* Utility library. */ + +#include <msg.h> +#include <mymalloc.h> +#include <connect.h> +#include <iostuff.h> + +/* TLS library. */ + +#include <tls_prng.h> + +/* tls_prng_file_open - open entropy file */ + +TLS_PRNG_SRC *tls_prng_file_open(const char *name, int timeout) +{ + const char *myname = "tls_prng_file_open"; + TLS_PRNG_SRC *fh; + int fd; + + if ((fd = open(name, O_RDONLY, 0)) < 0) { + if (msg_verbose) + msg_info("%s: cannot open entropy file %s: %m", myname, name); + return (0); + } else { + fh = (TLS_PRNG_SRC *) mymalloc(sizeof(*fh)); + fh->fd = fd; + fh->name = mystrdup(name); + fh->timeout = timeout; + if (msg_verbose) + msg_info("%s: opened entropy file %s", myname, name); + return (fh); + } +} + +/* tls_prng_file_read - update internal PRNG from entropy file */ + +ssize_t tls_prng_file_read(TLS_PRNG_SRC *fh, size_t len) +{ + const char *myname = "tls_prng_file_read"; + char buffer[8192]; + ssize_t to_read; + ssize_t count; + + if (msg_verbose) + msg_info("%s: seed internal pool from file %s", myname, fh->name); + + if (lseek(fh->fd, 0, SEEK_SET) < 0) { + if (msg_verbose) + msg_info("cannot seek entropy file %s: %m", fh->name); + return (-1); + } + errno = 0; + for (to_read = len; to_read > 0; to_read -= count) { + if ((count = timed_read(fh->fd, buffer, to_read > sizeof(buffer) ? + sizeof(buffer) : to_read, + fh->timeout, (void *) 0)) < 0) { + if (msg_verbose) + msg_info("cannot read entropy file %s: %m", fh->name); + return (-1); + } + if (count == 0) + break; + RAND_seed(buffer, count); + } + if (msg_verbose) + msg_info("read %ld bytes from entropy file %s: %m", + (long) (len - to_read), fh->name); + return (len - to_read); +} + +/* tls_prng_file_close - close entropy file */ + +int tls_prng_file_close(TLS_PRNG_SRC *fh) +{ + const char *myname = "tls_prng_file_close"; + int err; + + if (msg_verbose) + msg_info("%s: close entropy file %s", myname, fh->name); + err = close(fh->fd); + myfree(fh->name); + myfree((void *) fh); + return (err); +} + +#endif |