On Fri, Mar 05, 2021 at 03:15:48PM +0100, Claudio Jeker wrote:
> RRDP also uses SHA256 hashes to validate files (before withdraws and
> updates). Again move this from the implementation in mft.c to validate.c
> this way it can be reused.
>
> OK?
ok tb
> --
> :wq Claudio
>
> Index: extern.h
> ===================================================================
> RCS file: /cvs/src/usr.sbin/rpki-client/extern.h,v
> retrieving revision 1.51
> diff -u -p -r1.51 extern.h
> --- extern.h 5 Mar 2021 12:33:19 -0000 1.51
> +++ extern.h 5 Mar 2021 14:00:29 -0000
> @@ -354,6 +354,7 @@ int valid_ta(const char *, struct auth
> int valid_cert(const char *, struct auth_tree *,
> const struct cert *);
> int valid_roa(const char *, struct auth_tree *, struct roa *);
> +int valid_filehash(const char *, const char *, size_t);
>
> /* Working with CMS files. */
>
> Index: mft.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/rpki-client/mft.c,v
> retrieving revision 1.28
> diff -u -p -r1.28 mft.c
> --- mft.c 4 Mar 2021 14:24:17 -0000 1.28
> +++ mft.c 5 Mar 2021 12:33:50 -0000
> @@ -434,61 +434,32 @@ out:
> }
>
> /*
> - * Check the hash value of a file.
> + * Check all files and their hashes in a MFT structure.
> * Return zero on failure, non-zero on success.
> */
> -static int
> -mft_validfilehash(const char *fn, const struct mftfile *m)
> +int
> +mft_check(const char *fn, struct mft *p)
> {
> - char filehash[SHA256_DIGEST_LENGTH];
> - char buffer[8192];
> + size_t i;
> + int rc = 1;
> char *cp, *path = NULL;
> - SHA256_CTX ctx;
> - ssize_t nr;
> - int fd;
>
> /* Check hash of file now, but first build path for it */
> cp = strrchr(fn, '/');
> assert(cp != NULL);
> assert(cp - fn < INT_MAX);
> - if (asprintf(&path, "%.*s/%s", (int)(cp - fn), fn, m->file) == -1)
> - err(1, NULL);
>
> - if ((fd = open(path, O_RDONLY)) == -1) {
> - warn("%s: referenced file %s", fn, m->file);
> + for (i = 0; i < p->filesz; i++) {
> + const struct mftfile *m = &p->files[i];
> + if (asprintf(&path, "%.*s/%s", (int)(cp - fn), fn,
> + m->file) == -1)
> + err(1, NULL);
> + if (!valid_filehash(path, m->hash, sizeof(m->hash))) {
> + warnx("%s: bad message digest for %s", fn, m->file);
> + rc = 0;
> + }
> free(path);
> - return 0;
> }
> - free(path);
> -
> - SHA256_Init(&ctx);
> - while ((nr = read(fd, buffer, sizeof(buffer))) > 0) {
> - SHA256_Update(&ctx, buffer, nr);
> - }
> - close(fd);
> -
> - SHA256_Final(filehash, &ctx);
> - if (memcmp(m->hash, filehash, SHA256_DIGEST_LENGTH) != 0) {
> - warnx("%s: bad message digest for %s", fn, m->file);
> - return 0;
> - }
> -
> - return 1;
> -}
> -
> -/*
> - * Check all files and their hashes in a MFT structure.
> - * Return zero on failure, non-zero on success.
> - */
> -int
> -mft_check(const char *fn, struct mft *p)
> -{
> - size_t i;
> - int rc = 1;
> -
> - for (i = 0; i < p->filesz; i++)
> - if (!mft_validfilehash(fn, &p->files[i]))
> - rc = 0;
>
> return rc;
> }
> Index: validate.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/rpki-client/validate.c,v
> retrieving revision 1.11
> diff -u -p -r1.11 validate.c
> --- validate.c 12 Sep 2020 15:46:48 -0000 1.11
> +++ validate.c 5 Mar 2021 13:59:46 -0000
> @@ -20,6 +20,7 @@
> #include <arpa/inet.h>
> #include <assert.h>
> #include <err.h>
> +#include <fcntl.h>
> #include <inttypes.h>
> #include <stdarg.h>
> #include <stdlib.h>
> @@ -237,6 +238,37 @@ valid_roa(const char *fn, struct auth_tr
> tracewarn(a);
> return 0;
> }
> +
> + return 1;
> +}
> +
> +/*
> + * Validate a file by verifying the SHA256 hash of that file.
> + * Returns 1 if valid, 0 otherwise.
> + */
> +int
> +valid_filehash(const char *fn, const char *hash, size_t hlen)
> +{
> + SHA256_CTX ctx;
> + char filehash[SHA256_DIGEST_LENGTH];
> + char buffer[8192];
> + ssize_t nr;
> + int fd;
> +
> + if (hlen != sizeof(filehash))
> + errx(1, "bad hash size");
> +
> + if ((fd = open(fn, O_RDONLY)) == -1)
> + return 0;
> +
> + SHA256_Init(&ctx);
> + while ((nr = read(fd, buffer, sizeof(buffer))) > 0)
> + SHA256_Update(&ctx, buffer, nr);
> + close(fd);
> +
> + SHA256_Final(filehash, &ctx);
> + if (memcmp(hash, filehash, sizeof(filehash)) != 0)
> + return 0;
>
> return 1;
> }
>
