This moves valid_filename() to validate.c and splits out a helper portable_filename() which can be used from the RSC code. While moving valid_filename() is not necessary, I thought it makes sense to keep the two functions next to each other.
I could not find a short name with valid_ prefix for portable_filename() that I liked. valid_posix_filename()? valid_checklist_file()? Also, valid_filename() could be stricter and enforce that the unique '.' is followed by a 3-letter suffix. Index: extern.h =================================================================== RCS file: /cvs/src/usr.sbin/rpki-client/extern.h,v retrieving revision 1.134 diff -u -p -r1.134 extern.h --- extern.h 9 May 2022 17:19:32 -0000 1.134 +++ extern.h 10 May 2022 06:03:19 -0000 @@ -502,6 +502,8 @@ int valid_cert(const char *, struct au int valid_roa(const char *, struct auth *, struct roa *); int valid_filehash(int, const char *, size_t); int valid_hash(unsigned char *, size_t, const char *, size_t); +int portable_filename(const char *, size_t); +int valid_filename(const char *, size_t); int valid_uri(const char *, size_t, const char *); int valid_origin(const char *, const char *); int valid_x509(char *, X509_STORE_CTX *, X509 *, struct auth *, Index: mft.c =================================================================== RCS file: /cvs/src/usr.sbin/rpki-client/mft.c,v retrieving revision 1.61 diff -u -p -r1.61 mft.c --- mft.c 9 May 2022 17:02:34 -0000 1.61 +++ mft.c 10 May 2022 06:03:19 -0000 @@ -127,27 +127,6 @@ rtype_from_file_extension(const char *fn } /* - * Validate that a filename listed on a Manifest only contains characters - * permitted in draft-ietf-sidrops-6486bis section 4.2.2 - */ -static int -valid_filename(const char *fn, size_t len) -{ - const unsigned char *c; - size_t i; - - for (c = fn, i = 0; i < len; i++, c++) - if (!isalnum(*c) && *c != '-' && *c != '_' && *c != '.') - return 0; - - c = memchr(fn, '.', len); - if (c == NULL || c != memrchr(fn, '.', len)) - return 0; - - return 1; -} - -/* * Check that the file is an ASPA, CER, CRL, GBR or a ROA. * Returns corresponding rtype or RTYPE_INVALID on error. */ Index: rsc.c =================================================================== RCS file: /cvs/src/usr.sbin/rpki-client/rsc.c,v retrieving revision 1.1 diff -u -p -r1.1 rsc.c --- rsc.c 9 May 2022 17:02:34 -0000 1.1 +++ rsc.c 10 May 2022 06:03:46 -0000 @@ -147,6 +147,8 @@ rsc_parse_filenamehash(struct parse *p, } if (elemsz == 2) { + ASN1_IA5STRING *filename; + file = sk_ASN1_TYPE_value(seq, i++); if (file->type != V_ASN1_IA5STRING) { warnx("%s: RSC FileNameAndHash: want ASN.1 IA5 string," @@ -154,25 +156,17 @@ rsc_parse_filenamehash(struct parse *p, ASN1_tag2str(file->type), file->type); goto out; } - fn = strndup((const char *)file->value.ia5string->data, - file->value.ia5string->length); - if (fn == NULL) - err(1, NULL); - /* - * filename must confirm to portable file name character set - * XXX: use valid_filename() instead - */ - if (strchr(fn, '/') != NULL) { - warnx("%s: path components disallowed in filename: %s", - p->fn, fn); - goto out; - } - if (strchr(fn, '\n') != NULL) { - warnx("%s: newline disallowed in filename: %s", - p->fn, fn); + filename = file->value.ia5string; + + if (!portable_filename(filename->data, filename->length)) { + warnx("%s: RSC FileNameAndHash: bad filename", p->fn); goto out; } + + fn = strndup(filename->data, filename->length); + if (fn == NULL) + err(1, NULL); } /* Now hash value. */ Index: validate.c =================================================================== RCS file: /cvs/src/usr.sbin/rpki-client/validate.c,v retrieving revision 1.31 diff -u -p -r1.31 validate.c --- validate.c 21 Apr 2022 09:53:07 -0000 1.31 +++ validate.c 10 May 2022 06:03:19 -0000 @@ -275,6 +275,42 @@ valid_hash(unsigned char *buf, size_t le } /* + * Validate that a filename only contains characters from the POSIX portable + * filename character set [A-Za-z0-9._-], see IEEE Std 1003.1-2013, 3.278. + */ +int +portable_filename(const char *fn, size_t len) +{ + const unsigned char *c; + size_t i; + + for (c = fn, i = 0; i < len; i++, c++) + if (!isalnum(*c) && *c != '-' && *c != '_' && *c != '.') + return 0; + return 1; +} + +/* + * Validate that a filename listed on a Manifest only contains characters + * permitted in draft-ietf-sidrops-6486bis section 4.2.2 + * Also ensure that there is exactly one '.'. + */ +int +valid_filename(const char *fn, size_t len) +{ + const unsigned char *c; + + if (!portable_filename(fn, len)) + return 0; + + c = memchr(fn, '.', len); + if (c == NULL || c != memrchr(fn, '.', len)) + return 0; + + return 1; +} + +/* * Validate a URI to make sure it is pure ASCII and does not point backwards * or doing some other silly tricks. To enforce the protocol pass either * https:// or rsync:// as proto, if NULL is passed no protocol is enforced.