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Diffstat (limited to 'common/mbox-util.c')
| -rw-r--r-- | common/mbox-util.c | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/common/mbox-util.c b/common/mbox-util.c new file mode 100644 index 0000000..76255ba --- /dev/null +++ b/common/mbox-util.c @@ -0,0 +1,282 @@ +/* mbox-util.c - Mail address helper functions + * Copyright (C) 1998-2010 Free Software Foundation, Inc. + * Copyright (C) 1998-2015 Werner Koch + * + * This file is part of GnuPG. + * + * 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/>. + */ + +/* NB: GPGME uses the same code to reflect our idea on how to extract + * a mail address from a user id. + */ + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> + +#include "util.h" +#include "mbox-util.h" + + +static int +string_count_chr (const char *string, int c) +{ + int count; + + for (count=0; *string; string++ ) + if ( *string == c ) + count++; + return count; +} + +static int +mem_count_chr (const void *buffer, int c, size_t length) +{ + const char *s = buffer; + int count; + + for (count=0; length; length--, s++) + if (*s == c) + count++; + return count; +} + + +/* This is a case-sensitive version of our memistr. I wonder why no + standard function memstr exists but I better do not use the name + memstr to avoid future conflicts. */ +static const char * +my_memstr (const void *buffer, size_t buflen, const char *sub) +{ + const unsigned char *buf = buffer; + const unsigned char *t = (const unsigned char *)buf; + const unsigned char *s = (const unsigned char *)sub; + size_t n = buflen; + + for ( ; n ; t++, n-- ) + { + if (*t == *s) + { + for (buf = t++, buflen = n--, s++; n && *t ==*s; t++, s++, n--) + ; + if (!*s) + return (const char*)buf; + t = (const unsigned char *)buf; + s = (const unsigned char *)sub ; + n = buflen; + } + } + return NULL; +} + + + +static int +string_has_ctrl_or_space (const char *string) +{ + for (; *string; string++ ) + if (!(*string & 0x80) && *string <= 0x20) + return 1; + return 0; +} + + +/* Return true if STRING has two consecutive '.' after an '@' + sign. */ +static int +has_dotdot_after_at (const char *string) +{ + string = strchr (string, '@'); + if (!string) + return 0; /* No at-sign. */ + string++; + return !!strstr (string, ".."); +} + + +/* Check whether BUFFER has characters not valid in an RFC-822 + address. LENGTH gives the length of BUFFER. + + To cope with OpenPGP we ignore non-ascii characters so that for + example umlauts are legal in an email address. An OpenPGP user ID + must be utf-8 encoded but there is no strict requirement for + RFC-822. Thus to avoid IDNA encoding we put the address verbatim + as utf-8 into the user ID under the assumption that mail programs + handle IDNA at a lower level and take OpenPGP user IDs as utf-8. + Note that we can't do an utf-8 encoding checking here because in + keygen.c this function is called with the native encoding and + native to utf-8 encoding is only done later. */ +int +has_invalid_email_chars (const void *buffer, size_t length) +{ + const unsigned char *s = buffer; + int at_seen=0; + const char *valid_chars= + "01234567890_-.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; + + for ( ; length && *s; length--, s++ ) + { + if ((*s & 0x80)) + continue; /* We only care about ASCII. */ + if (*s == '@') + at_seen=1; + else if (!at_seen && !(strchr (valid_chars, *s) + || strchr ("!#$%&'*+/=?^`{|}~", *s))) + return 1; + else if (at_seen && !strchr (valid_chars, *s)) + return 1; + } + return 0; +} + + +/* Same as is_valid_mailbox (see below) but operates on non-nul + terminated buffer. */ +int +is_valid_mailbox_mem (const void *name_arg, size_t namelen) +{ + const char *name = name_arg; + + return !( !name + || !namelen + || has_invalid_email_chars (name, namelen) + || mem_count_chr (name, '@', namelen) != 1 + || *name == '@' + || name[namelen-1] == '@' + || name[namelen-1] == '.' + || my_memstr (name, namelen, "..")); +} + + +/* Check whether NAME represents a valid mailbox according to + RFC822. Returns true if so. */ +int +is_valid_mailbox (const char *name) +{ + return name? is_valid_mailbox_mem (name, strlen (name)) : 0; +} + + +/* Return the mailbox (local-part@domain) form a standard user id. + All plain ASCII characters in the result are converted to + lowercase. Caller must free the result. Returns NULL if no valid + mailbox was found (or we are out of memory). */ +char * +mailbox_from_userid (const char *userid) +{ + const char *s, *s_end; + size_t len; + char *result = NULL; + + s = strchr (userid, '<'); + if (s) + { + /* Seems to be a standard user id. */ + s++; + s_end = strchr (s, '>'); + if (s_end && s_end > s) + { + len = s_end - s; + result = xtrymalloc (len + 1); + if (!result) + return NULL; /* Ooops - out of core. */ + strncpy (result, s, len); + result[len] = 0; + /* Apply some basic checks on the address. We do not use + is_valid_mailbox because those checks are too strict. */ + if (string_count_chr (result, '@') != 1 /* Need exactly one '@. */ + || *result == '@' /* local-part missing. */ + || result[len-1] == '@' /* domain missing. */ + || result[len-1] == '.' /* ends with a dot. */ + || string_has_ctrl_or_space (result) + || has_dotdot_after_at (result)) + { + xfree (result); + result = NULL; + errno = EINVAL; + } + } + else + errno = EINVAL; + } + else if (is_valid_mailbox (userid)) + { + /* The entire user id is a mailbox. Return that one. Note that + this fallback method has some restrictions on the valid + syntax of the mailbox. However, those who want weird + addresses should know about it and use the regular <...> + syntax. */ + result = xtrystrdup (userid); + } + else + errno = EINVAL; + + return result? ascii_strlwr (result): NULL; +} + + +/* Check whether UID is a valid standard user id of the form + "Heinrich Heine <heinrichh@duesseldorf.de>" + and return true if this is the case. */ +int +is_valid_user_id (const char *uid) +{ + if (!uid || !*uid) + return 0; + + return 1; +} + + +/* Returns true if STRING is a valid domain name according to the LDH + * rule. */ +int +is_valid_domain_name (const char *string) +{ + static char const ldh_chars[] = + "01234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-"; + const char *s; + + /* Note that we do not check the length limit of a label or the + * entire name */ + + for (s=string; *s; s++) + if (*s == '.') + { + if (string == s) + return 0; /* Dot at the start of the string. */ + /* (may also be at the end like in ".") */ + if (s[1] == '.') + return 0; /* No - double dot. */ + } + else if (!strchr (ldh_chars, *s)) + return 0; + else if (*s == '-') + { + if (string == s) + return 0; /* Leading hyphen. */ + if (s[-1] == '.') + return 0; /* Hyphen at begin of a label. */ + if (s[1] == '.') + return 0; /* Hyphen at start of a label. */ + if (!s[1]) + return 0; /* Trailing hyphen. */ + } + + return !!*string; +} |