diff options
Diffstat (limited to 'kbx/keybox-file.c')
| -rw-r--r-- | kbx/keybox-file.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/kbx/keybox-file.c b/kbx/keybox-file.c new file mode 100644 index 0000000..c36f5be --- /dev/null +++ b/kbx/keybox-file.c @@ -0,0 +1,190 @@ +/* keybox-file.c - File operations + * Copyright (C) 2001, 2003 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * GnuPG 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <time.h> + +#include "keybox-defs.h" + + +#define IMAGELEN_LIMIT (5*1024*1024) + + +#if !defined(HAVE_FTELLO) && !defined(ftello) +static off_t +ftello (FILE *stream) +{ + long int off; + + off = ftell (stream); + if (off == -1) + return (off_t)-1; + return off; +} +#endif /* !defined(HAVE_FTELLO) && !defined(ftello) */ + + + +/* Read a block at the current position and return it in R_BLOB. + R_BLOB may be NULL to simply skip the current block. */ +int +_keybox_read_blob (KEYBOXBLOB *r_blob, estream_t fp, int *skipped_deleted) +{ + unsigned char *image; + size_t imagelen = 0; + int c1, c2, c3, c4, type; + int rc; + off_t off; + + if (skipped_deleted) + *skipped_deleted = 0; + again: + if (r_blob) + *r_blob = NULL; + off = es_ftello (fp); + if (off == (off_t)-1) + return gpg_error_from_syserror (); + + if ((c1 = es_getc (fp)) == EOF + || (c2 = es_getc (fp)) == EOF + || (c3 = es_getc (fp)) == EOF + || (c4 = es_getc (fp)) == EOF + || (type = es_getc (fp)) == EOF) + { + if ( c1 == EOF && !es_ferror (fp) ) + return -1; /* eof */ + if (!es_ferror (fp)) + return gpg_error (GPG_ERR_TOO_SHORT); + return gpg_error_from_syserror (); + } + + imagelen = ((unsigned int) c1 << 24) | (c2 << 16) | (c3 << 8 ) | c4; + if (imagelen < 5) + return gpg_error (GPG_ERR_TOO_SHORT); + + if (!type) + { + /* Special treatment for empty blobs. */ + if (es_fseek (fp, imagelen-5, SEEK_CUR)) + return gpg_error_from_syserror (); + if (skipped_deleted) + *skipped_deleted = 1; + goto again; + } + + if (imagelen > IMAGELEN_LIMIT) /* Sanity check. */ + { + /* Seek forward so that the caller may choose to ignore this + record. */ + if (es_fseek (fp, imagelen-5, SEEK_CUR)) + return gpg_error_from_syserror (); + return gpg_error (GPG_ERR_TOO_LARGE); + } + + if (!r_blob) + { + /* This blob shall be skipped. */ + if (es_fseek (fp, imagelen-5, SEEK_CUR)) + return gpg_error_from_syserror (); + return 0; + } + + image = xtrymalloc (imagelen); + if (!image) + return gpg_error_from_syserror (); + + image[0] = c1; image[1] = c2; image[2] = c3; image[3] = c4; image[4] = type; + if (es_fread (image+5, imagelen-5, 1, fp) != 1) + { + gpg_error_t tmperr = gpg_error_from_syserror (); + xfree (image); + return tmperr; + } + + rc = _keybox_new_blob (r_blob, image, imagelen, off); + if (rc) + xfree (image); + return rc; +} + + +/* Write the block to the current file position */ +int +_keybox_write_blob (KEYBOXBLOB blob, estream_t fp, FILE *outfp) +{ + const unsigned char *image; + size_t length; + + image = _keybox_get_blob_image (blob, &length); + + if (length > IMAGELEN_LIMIT) + return gpg_error (GPG_ERR_TOO_LARGE); + + if (fp) + { + if (es_fwrite (image, length, 1, fp) != 1) + return gpg_error_from_syserror (); + } + else + { + if (fwrite (image, length, 1, outfp) != 1) + return gpg_error_from_syserror (); + } + + return 0; +} + + +/* Write a fresh header type blob. */ +int +_keybox_write_header_blob (estream_t fp, int for_openpgp) +{ + unsigned char image[32]; + u32 val; + + memset (image, 0, sizeof image); + /* Length of this blob. */ + image[3] = 32; + + image[4] = KEYBOX_BLOBTYPE_HEADER; + image[5] = 1; /* Version */ + if (for_openpgp) + image[7] = 0x02; /* OpenPGP data may be available. */ + + memcpy (image+8, "KBXf", 4); + val = time (NULL); + /* created_at and last maintenance run. */ + image[16] = (val >> 24); + image[16+1] = (val >> 16); + image[16+2] = (val >> 8); + image[16+3] = (val ); + image[20] = (val >> 24); + image[20+1] = (val >> 16); + image[20+2] = (val >> 8); + image[20+3] = (val ); + + if (es_fwrite (image, 32, 1, fp) != 1) + return gpg_error_from_syserror (); + + return 0; +} |