/* $OpenBSD: tls_util.c,v 1.17 2026/03/10 05:26:04 deraadt Exp $ */
/*
 * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
 * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
 * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/stat.h>

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>

#include "tls.h"
#include "tls_internal.h"

static void *
memdup(const void *in, size_t len)
{
        void *out;

        if ((out = malloc(len)) == NULL)
                return NULL;
        memcpy(out, in, len);
        return out;
}

int
tls_set_mem(char **dest, size_t *destlen, const void *src, size_t srclen)
{
        free(*dest);
        *dest = NULL;
        *destlen = 0;
        if (src != NULL) {
                if ((*dest = memdup(src, srclen)) == NULL)
                        return -1;
                *destlen = srclen;
        }
        return 0;
}

int
tls_set_string(const char **dest, const char *src)
{
        free((char *)*dest);
        *dest = NULL;
        if (src != NULL)
                if ((*dest = strdup(src)) == NULL)
                        return -1;
        return 0;
}

/*
 * Extract the host and port from a colon separated value. For a literal IPv6
 * address the address must be contained with square braces. If a host and
 * port are successfully extracted, the function will return 0 and the
 * caller is responsible for freeing the host and port. If no port is found
 * then the function will return 1, with both host and port being NULL.
 * On memory allocation failure -1 will be returned.
 */
int
tls_host_port(const char *hostport, char **host, char **port)
{
        char *h, *p, *s;
        int rv = 1;

        *host = NULL;
        *port = NULL;

        if ((s = strdup(hostport)) == NULL)
                goto err;

        h = p = s;

        /* See if this is an IPv6 literal with square braces. */
        if (p[0] == '[') {
                h++;
                if ((p = strchr(s, ']')) == NULL)
                        goto done;
                *p++ = '\0';
        }

        /* Find the port separator. */
        if ((p = strchr(p, ':')) == NULL)
                goto done;

        /* If there is another separator then we have issues. */
        if (strchr(p + 1, ':') != NULL)
                goto done;

        *p++ = '\0';

        if (asprintf(host, "%s", h) == -1) {
                *host = NULL;
                goto err;
        }
        if (asprintf(port, "%s", p) == -1) {
                *port = NULL;
                goto err;
        }

        rv = 0;
        goto done;

 err:
        free(*host);
        *host = NULL;
        free(*port);
        *port = NULL;
        rv = -1;

 done:
        free(s);

        return (rv);
}

int
tls_password_cb(char *buf, int size, int rwflag, void *u)
{
        size_t len;

        if (size < 0)
                return (0);

        if (u == NULL) {
                memset(buf, 0, size);
                return (0);
        }

        if ((len = strlcpy(buf, u, size)) >= (size_t)size)
                return (0);

        return (len);
}

uint8_t *
tls_load_file(const char *name, size_t *len, char *password)
{
        FILE *fp;
        EVP_PKEY *key = NULL;
        BIO *bio = NULL;
        char *data;
        uint8_t *buf = NULL;
        struct stat st;
        size_t size = 0;
        int fd = -1;
        ssize_t n;

        *len = 0;

        if ((fd = open(name, O_RDONLY|O_CLOEXEC)) == -1)
                return (NULL);

        /* Just load the file into memory without decryption */
        if (password == NULL) {
                if (fstat(fd, &st) != 0)
                        goto err;
                if (st.st_size < 0)
                        goto err;
                size = (size_t)st.st_size;
                if ((buf = malloc(size)) == NULL)
                        goto err;
                n = read(fd, buf, size);
                if (n < 0 || (size_t)n != size)
                        goto err;
                close(fd);
                goto done;
        }

        /* Or read the (possibly) encrypted key from file */
        if ((fp = fdopen(fd, "r")) == NULL)
                goto err;
        fd = -1;

        key = PEM_read_PrivateKey(fp, NULL, tls_password_cb, password);
        fclose(fp);
        if (key == NULL)
                goto err;

        /* Write unencrypted key to memory buffer */
        if ((bio = BIO_new(BIO_s_mem())) == NULL)
                goto err;
        if (!PEM_write_bio_PrivateKey(bio, key, NULL, NULL, 0, NULL, NULL))
                goto err;
        if ((size = BIO_get_mem_data(bio, &data)) <= 0)
                goto err;
        if ((buf = malloc(size)) == NULL)
                goto err;
        memcpy(buf, data, size);

        BIO_free_all(bio);
        EVP_PKEY_free(key);

 done:
        *len = size;
        return (buf);

 err:
        if (fd != -1)
                close(fd);
        freezero(buf, size);
        BIO_free_all(bio);
        EVP_PKEY_free(key);

        return (NULL);
}

void
tls_unload_file(uint8_t *buf, size_t len)
{
        freezero(buf, len);
}