diff options
Diffstat (limited to 'src/name-value.c')
| -rw-r--r-- | src/name-value.c | 895 |
1 files changed, 895 insertions, 0 deletions
diff --git a/src/name-value.c b/src/name-value.c new file mode 100644 index 0000000..82d4810 --- /dev/null +++ b/src/name-value.c @@ -0,0 +1,895 @@ +/* name-value.c - Parser and writer for a name-value format. + * Copyright (C) 2016, 2025 g10 Code GmbH + * + * This file is part of Libgpg-error. + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as + * published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * This file 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 Lesser General Public License + * along with this program; if not, see <https://www.gnu.org/licenses/>. + * SPDX-License-Identifier: LGPL-2.1-or-later + * + * This file was originally a part of GnuPG. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include <stdlib.h> +#include <string.h> + +#include "gpgrt-int.h" + + +struct _gpgrt_name_value_container +{ + struct _gpgrt_name_value_entry *first; + struct _gpgrt_name_value_entry *last; + unsigned int wipe_on_free:1; + unsigned int private_key_mode:1; + unsigned int modified:1; +}; + + +struct _gpgrt_name_value_entry +{ + struct _gpgrt_name_value_entry *prev; + struct _gpgrt_name_value_entry *next; + + unsigned int wipe_on_free:1; /* Copied from the container. */ + + /* The name. Comments and blank lines have NAME set to NULL. */ + char *name; + + /* The value as stored in the file. We store it when we parse + * a file so that we can reproduce it. */ + gpgrt_strlist_t raw_value; + + /* The decoded value. */ + char *value; +}; + + +/* This macro is a simple ascii only versions of the standard (and + * locale affected) isspace(3). This macro does not consider \v and + * \f as white space not any non-ascii character. */ +#define ascii_isspace(a) ((a)==' ' || (a)=='\n' || (a)=='\r' || (a)=='\t') + +/* Other simple macros. */ +#define spacep(p) (*(p) == ' ' || *(p) == '\t') +#define digitp(p) (*(p) >= '0' && *(p) <= '9') +#define alphap(p) ((*(p) >= 'A' && *(p) <= 'Z') \ + || (*(p) >= 'a' && *(p) <= 'z')) +#define alnump(p) (alphap (p) || digitp (p)) + + +static GPGRT_INLINE int +ascii_toupper (int c) +{ + if (c >= 'a' && c <= 'z') + c &= ~0x20; + return c; +} + + +static int +ascii_strcasecmp (const char *a, const char *b) +{ + if (a == b) + return 0; + + for (; *a && *b; a++, b++) + { + if (*a != *b && ascii_toupper(*a) != ascii_toupper(*b)) + break; + } + return *a == *b? 0 : (ascii_toupper (*a) - ascii_toupper (*b)); +} + + + + +/* Allocate a name value container structure. */ +gpgrt_nvc_t +_gpgrt_nvc_new (unsigned int flags) +{ + gpgrt_nvc_t nvc; + + nvc = xtrycalloc (1, sizeof *nvc); + if (!nvc) + return NULL; + nvc->modified = 1; + if ((flags & GPGRT_NVC_PRIVKEY)) + { + nvc->wipe_on_free = 1; + nvc->private_key_mode = 1; + } + else if ((flags & GPGRT_NVC_WIPE)) + nvc->wipe_on_free = 1; + + return nvc; +} + + +/* Helper to free an entry. */ +static void +nve_release (gpgrt_nve_t entry, int with_wipe) +{ + if (!entry) + return; + + xfree (entry->name); + if (entry->value && with_wipe) + _gpgrt_wipememory (entry->value, strlen (entry->value)); + xfree (entry->value); + _gpgrt_strlist_free (entry->raw_value); + xfree (entry); +} + + +/* Release a name value container. */ +void +_gpgrt_nvc_release (gpgrt_nvc_t cont) +{ + gpgrt_nve_t e, next; + + if (!cont) + return; + + for (e = cont->first; e; e = next) + { + next = e->next; + nve_release (e, cont->wipe_on_free); + } + + xfree (cont); +} + + +/* Return true if the specified flag is set. Only one bit should be + * set in FLAGS. If the GPGRT_NVC_MODIFIED flag is requested and + * CLEAR is set, that flag is cleared; note that this modified flag is + * set for a new container and set with each update. */ +int +_gpgrt_nvc_get_flag (gpgrt_nvc_t cont, unsigned int flags, int clear) +{ + int ret = 0; + + if (!cont) + ; + else if ((flags & GPGRT_NVC_MODIFIED)) + { + ret = cont->modified; + if (clear) + cont->modified = 0; + } + else if ((flags & GPGRT_NVC_PRIVKEY)) + ret = cont->private_key_mode; + else if ((flags & GPGRT_NVC_WIPE)) + ret = cont->wipe_on_free; + + return !!ret; +} + + + +/* Dealing with names and values. */ + +/* Check whether the given name is valid. Valid names start with a + * letter, end with a colon, and contain only alphanumeric characters + * and the hyphen. Returns true if NAME is valid. */ +static int +valid_name (const char *name) +{ + size_t i; + size_t len = strlen (name); + + if (! alphap (name) || !len || name[len - 1] != ':') + return 0; + + for (i = 1; i < len - 1; i++) + if (!alnump (name + i) && name[i] != '-') + return 0; + + return 1; +} + + +/* Makes sure that ENTRY has a RAW_VALUE. */ +static gpg_err_code_t +assert_raw_value (gpgrt_nve_t entry) +{ + gpg_err_code_t err = 0; + size_t len, offset; +#define LINELEN 70 + char buf[LINELEN+3]; + + if (entry->raw_value) + return 0; + + len = strlen (entry->value); + offset = 0; + while (len) + { + size_t amount, linelen = LINELEN; + + /* On the first line we need to subtract space for the name. */ + if (entry->raw_value == NULL && strlen (entry->name) < linelen) + linelen -= strlen (entry->name); + + /* See if the rest of the value fits in this line. */ + if (len <= linelen) + amount = len; + else + { + size_t i; + + /* Find a suitable space to break on. */ + for (i = linelen - 1; linelen - i < 30; i--) + if (ascii_isspace (entry->value[offset+i])) + break; + + if (ascii_isspace (entry->value[offset+i])) + { + /* Found one. */ + amount = i; + } + else + { + /* Just induce a hard break. */ + amount = linelen; + } + } + + snprintf (buf, sizeof buf, " %.*s\n", (int) amount, + &entry->value[offset]); + if (!_gpgrt_strlist_add (&entry->raw_value, buf, + (GPGRT_STRLIST_APPEND + | (entry->wipe_on_free? GPGRT_STRLIST_WIPE:0)))) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + + offset += amount; + len -= amount; + } + + leave: + if (err) + { + _gpgrt_strlist_free (entry->raw_value); + entry->raw_value = NULL; + } + + return err; +#undef LINELEN +} + + +/* Computes the length of the value encoded as continuation. If + * *SWALLOW_WS is set, all whitespace at the beginning of S is + * swallowed. If START is given, a pointer to the beginning of the + * value is stored there. */ +static size_t +continuation_length (const char *s, int *swallow_ws, const char **start) +{ + size_t len; + + if (*swallow_ws) + { + /* The previous line was a blank line and we inserted a newline. + Swallow all whitespace at the beginning of this line. */ + while (ascii_isspace (*s)) + s++; + } + else + { + /* Iff a continuation starts with more than one space, it + encodes a space. */ + if (ascii_isspace (*s)) + s++; + } + + /* Strip whitespace at the end. */ + len = strlen (s); + while (len > 0 && ascii_isspace (s[len-1])) + len--; + + if (!len) + { + /* Blank lines encode newlines. */ + len = 1; + s = "\n"; + *swallow_ws = 1; + } + else + *swallow_ws = 0; + + if (start) + *start = s; + + return len; +} + + +/* Makes sure that ENTRY has a VALUE. */ +static gpg_err_code_t +assert_value (gpgrt_nve_t entry) +{ + size_t len; + int swallow_ws; + gpgrt_strlist_t s; + char *p; + + if (entry->value) + return 0; + + len = 0; + swallow_ws = 0; + for (s = entry->raw_value; s; s = s->next) + len += continuation_length (s->d, &swallow_ws, NULL); + + /* Add one for the terminating zero. */ + len += 1; + + entry->value = p = xtrymalloc (len); + if (!entry->value) + return _gpg_err_code_from_syserror (); + + swallow_ws = 0; + for (s = entry->raw_value; s; s = s->next) + { + const char *start; + size_t l = continuation_length (s->d, &swallow_ws, &start); + + memcpy (p, start, l); + p += l; + } + + *p++ = 0; + gpgrt_assert (p - entry->value == len); + + return 0; +} + + +/* Get the name. */ +const char * +_gpgrt_nve_name (gpgrt_nve_t entry) +{ + return entry->name; +} + + +/* Get the value. */ +const char * +_gpgrt_nve_value (gpgrt_nve_t entry) +{ + if (assert_value (entry)) + return NULL; + return entry->value; +} + + + +/* Adding and modifying values. */ + +/* Add (NAME, VALUE, RAW_VALUE) to CONT. NAME may be NULL for comments + * and blank lines. At least one of VALUE and RAW_VALUE must be + * given. If PRESERVE_ORDER is not given, entries with the same name + * are grouped. NAME, VALUE and RAW_VALUE is consumed. */ +static gpg_err_code_t +do_nvc_add (gpgrt_nvc_t cont, char *name, char *value, + gpgrt_strlist_t raw_value, int preserve_order) +{ + gpg_err_code_t err = 0; + gpgrt_nve_t e; + + gpgrt_assert (value || raw_value); + + if (name && ! valid_name (name)) + { + err = GPG_ERR_INV_NAME; + goto leave; + } + + if (name + && cont->private_key_mode + && !ascii_strcasecmp (name, "Key:") + && _gpgrt_nvc_lookup (cont, "Key:")) + { + err = GPG_ERR_INV_NAME; + goto leave; + } + + e = xtrycalloc (1, sizeof *e); + if (!e) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + + e->name = name; + e->value = value; + e->raw_value = raw_value; + e->wipe_on_free = cont->wipe_on_free; + + if (cont->first) + { + gpgrt_nve_t last; + + if (preserve_order || !name) + last = cont->last; + else + { + /* See if there is already an entry with NAME. */ + last = _gpgrt_nvc_lookup (cont, name); + + /* If so, find the last in that block. */ + if (last) + { + while (last->next) + { + gpgrt_nve_t next = last->next; + + if (next->name && !ascii_strcasecmp (next->name, name)) + last = next; + else + break; + } + } + else /* Otherwise, just find the last entry. */ + last = cont->last; + } + + if (last->next) + { + e->prev = last; + e->next = last->next; + last->next = e; + e->next->prev = e; + } + else + { + e->prev = last; + last->next = e; + cont->last = e; + } + } + else + cont->first = cont->last = e; + + cont->modified = 1; + + leave: + if (err) + { + xfree (name); + if (value && cont->wipe_on_free) + _gpgrt_wipememory (value, strlen (value)); + xfree (value); + _gpgrt_strlist_free (raw_value); + } + + return err; +} + + +/* Add (NAME, VALUE) to CONT. If an entry with NAME already exists, it + * is not updated but the new entry is appended. */ +gpg_err_code_t +_gpgrt_nvc_add (gpgrt_nvc_t cont, const char *name, const char *value) +{ + char *k, *v; + + k = xtrystrdup (name); + if (!k) + return _gpg_err_code_from_syserror (); + + v = xtrystrdup (value); + if (!v) + { + xfree (k); + return _gpg_err_code_from_syserror (); + } + + return do_nvc_add (cont, k, v, NULL, 0); +} + + +/* Add (NAME, VALUE) to CONT. If an entry with NAME already exists, it + * is updated with VALUE. If multiple entries with NAME exist, the + * first entry is updated. */ +gpg_err_code_t +_gpgrt_nvc_set (gpgrt_nvc_t cont, const char *name, const char *value) +{ + gpgrt_nve_t e; + + if (! valid_name (name)) + return GPG_ERR_INV_NAME; + + e = _gpgrt_nvc_lookup (cont, name); + if (e) + return _gpgrt_nve_set (cont, e, value); + else + return _gpgrt_nvc_add (cont, name, value); +} + + +/* Update entry E to VALUE. CONT is optional; if given its modified + * flag will be updated. */ +gpg_err_code_t +_gpgrt_nve_set (gpgrt_nvc_t cont, gpgrt_nve_t e, const char *value) +{ + char *v; + + if (!e) + return GPG_ERR_INV_ARG; + + if (e->value && value && !strcmp (e->value, value)) + { + /* Setting same value - ignore this call and don't set the + * modified flag (if CONT is given). */ + return 0; + } + + v = xtrystrdup (value? value:""); + if (!v) + return _gpg_err_code_from_syserror (); + + _gpgrt_strlist_free (e->raw_value); + e->raw_value = NULL; + if (e->value) + _gpgrt_wipememory (e->value, strlen (e->value)); + xfree (e->value); + e->value = v; + if (cont) + cont->modified = 1; + + return 0; +} + + +/* Delete the given ENTRY from the container CONT. */ +static void +do_nvc_delete (gpgrt_nvc_t cont, gpgrt_nve_t entry) +{ + if (entry->prev) + entry->prev->next = entry->next; + else + cont->first = entry->next; + + if (entry->next) + entry->next->prev = entry->prev; + else + cont->last = entry->prev; + + nve_release (entry, cont->private_key_mode); + cont->modified = 1; +} + + +/* Delete entries from the container CONT. Either ENTRY or NAME may + * be given. IF Entry is given only this entry is removed. if NAME + * is given all entries with this name are deleted. */ +void +_gpgrt_nvc_delete (gpgrt_nvc_t cont, gpgrt_nve_t entry, const char *name) +{ + if (entry) + do_nvc_delete (cont, entry); + else if (valid_name (name)) + { + while ((entry = _gpgrt_nvc_lookup (cont, name))) + do_nvc_delete (cont, entry); + } +} + + + +/* Lookup and iteration. */ + +/* Get the first entry with the given name. Return NULL if it does + * not exist. This function allows to specify NAME without the + * trailing colon as long as name is not too long. If NAME is NULL + * the first non-comment entry is returned. */ +gpgrt_nve_t +_gpgrt_nvc_lookup (gpgrt_nvc_t cont, const char *name) +{ + gpgrt_nve_t entry; + size_t n; + char buffer[40]; + + if (!cont) + return NULL; + + if (!name) + { + for (entry = cont->first; entry; entry = entry->next) + if (entry->name) + return entry; + + return NULL; + } + + if ((n=strlen (name)) && name[n-1] != ':' && n + 2 < sizeof buffer) + { + strcpy (stpcpy (buffer, name), ":"); + name = buffer; + } + + for (entry = cont->first; entry; entry = entry->next) + if (entry->name && !ascii_strcasecmp (entry->name, name)) + return entry; + + return NULL; +} + + +/* Get the next non-comment entry. If NAME is given the next entry + * with that name is returned. */ +gpgrt_nve_t +_gpgrt_nve_next (gpgrt_nve_t entry, const char *name) +{ + if (!entry) + return NULL; + + if (name) + { + for (entry = entry->next; entry; entry = entry->next) + if (entry->name && !ascii_strcasecmp (entry->name, name)) + return entry; + } + else + { + for (entry = entry->next; entry; entry = entry->next) + if (entry->name) + return entry; + } + return NULL; +} + + + +/* Parsing and serialization. */ + +static gpg_err_code_t +do_nvc_parse (gpgrt_nvc_t *result, int *errlinep, estream_t stream, + unsigned int flags) +{ + gpg_err_code_t err = 0; + gpgrt_ssize_t len; + char *buf = NULL; + size_t buf_len = 0; + char *name = NULL; + gpgrt_strlist_t raw_value = NULL; + unsigned int slflags; + + *result = _gpgrt_nvc_new (flags); + if (!*result) + return _gpg_err_code_from_syserror (); + + slflags = (GPGRT_STRLIST_APPEND + | ((flags & GPGRT_NVC_WIPE)? GPGRT_STRLIST_WIPE:0)); + + if (errlinep) + *errlinep = 0; + while ((len = _gpgrt_read_line (stream, &buf, &buf_len, NULL)) > 0) + { + char *p; + if (errlinep) + *errlinep += 1; + + /* Skip any whitespace. */ + for (p = buf; *p && ascii_isspace (*p); p++) + /* Do nothing. */; + + if (name && (spacep (buf) || !*p)) + { + /* A continuation. */ + if (!_gpgrt_strlist_add (&raw_value, buf, slflags)) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + continue; + } + + /* No continuation. Add the current entry if any. */ + if (raw_value) + { + err = do_nvc_add (*result, name, NULL, + raw_value, 1 /*preserve order*/); + name = NULL; + if (err) + goto leave; + } + + /* And prepare for the next one. */ + name = NULL; + raw_value = NULL; + + if (*p != 0 && *p != '#') + { + char *colon, *value, tmp; + + colon = strchr (buf, ':'); + if (!colon) + { + err = GPG_ERR_INV_VALUE; + goto leave; + } + + value = colon + 1; + tmp = *value; + *value = 0; + name = xtrystrdup (p); + *value = tmp; + if (!name) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + + if (!_gpgrt_strlist_add (&raw_value, value, slflags)) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + continue; + } + + if (!_gpgrt_strlist_add (&raw_value, buf, slflags)) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + } + if (len < 0) + { + err = _gpg_err_code_from_syserror (); + goto leave; + } + + /* Add the final entry. */ + if (raw_value) + { + err = do_nvc_add (*result, name, NULL, raw_value, 1 /*preserve order*/); + name = NULL; + } + + leave: + xfree (name); + xfree (buf); + if (err) + { + _gpgrt_nvc_release (*result); + *result = NULL; + } + + return err; +} + + +/* Parse STREAM and return a newly allocated name value container + * structure in RESULT. If ERRLINEP is given, the line number the + * parser was last considering is stored there. For private key + * containers the GPGRT_NVC_PRIVKEY bit should be set in FLAGS. */ +gpg_err_code_t +_gpgrt_nvc_parse (gpgrt_nvc_t *result, int *errlinep, estream_t stream, + unsigned int flags) +{ + return do_nvc_parse (result, errlinep, stream, flags); +} + + +/* Helper for nvc_write. */ +static gpg_err_code_t +write_one_entry (gpgrt_nve_t entry, estream_t stream) +{ + gpg_err_code_t err; + gpgrt_strlist_t sl; + + if (entry->name) + _gpgrt_fputs (entry->name, stream); + + err = assert_raw_value (entry); + if (err) + return err; + + for (sl = entry->raw_value; sl; sl = sl->next) + _gpgrt_fputs (sl->d, stream); + + if (_gpgrt_ferror (stream)) + return _gpg_err_code_from_syserror (); + + return 0; +} + + +/* Write a representation of CONT to STREAM. */ +gpg_err_code_t +_gpgrt_nvc_write (gpgrt_nvc_t cont, estream_t stream) +{ + gpg_err_code_t err = 0; + gpgrt_nve_t entry; + gpgrt_nve_t keyentry = NULL; + + for (entry = cont->first; entry; entry = entry->next) + { + if (cont->private_key_mode + && entry->name && !ascii_strcasecmp (entry->name, "Key:")) + { + if (!keyentry) + keyentry = entry; + continue; + } + + err = write_one_entry (entry, stream); + if (err) + return err; + } + + /* In private key mode we write the Key always last. */ + if (keyentry) + err = write_one_entry (keyentry, stream); + + return err; +} + + + +/* + * Convenience functions. + */ + +/* Return the string for the first entry in NVC with NAME. If an + * entry with NAME is missing in NVC or its value is the empty string + * NULL is returned. Note that the returned string is a pointer + * into NVC. */ +const char * +_gpgrt_nvc_get_string (gpgrt_nvc_t nvc, const char *name) +{ + gpgrt_nve_t item; + + if (!nvc) + return NULL; + item = _gpgrt_nvc_lookup (nvc, name); + if (!item) + return NULL; + return _gpgrt_nve_value (item); +} + + +/* Return true (ie. a non-zero value) if NAME exists and its value is + * true; that is either "yes", "true", or a decimal value unequal to 0. */ +int +_gpgrt_nvc_get_bool (gpgrt_nvc_t nvc, const char *name) +{ + gpgrt_nve_t item; + const char *s; + int n; + + if (!nvc) + return 0; + item = _gpgrt_nvc_lookup (nvc, name); + if (!item) + return 0; + s = _gpgrt_nve_value (item); + if (!s) + return 0; + n = atoi (s); + if (n) + return n; + if (!ascii_strcasecmp (s, "yes") || !ascii_strcasecmp (s, "true")) + return 1; + return 0; +} |