diff options
Diffstat (limited to 'krl.c')
-rw-r--r-- | krl.c | 283 |
1 files changed, 216 insertions, 67 deletions
@@ -14,11 +14,10 @@ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ -/* $OpenBSD: krl.c,v 1.31 2015/01/30 01:10:33 djm Exp $ */ +/* $OpenBSD: krl.c,v 1.50 2020/04/03 05:48:57 djm Exp $ */ #include "includes.h" -#include <sys/param.h> /* MIN */ #include <sys/types.h> #include <openbsd-compat/sys-tree.h> #include <openbsd-compat/sys-queue.h> @@ -26,6 +25,7 @@ #include <errno.h> #include <fcntl.h> #include <limits.h> +#include <stdlib.h> #include <string.h> #include <time.h> #include <unistd.h> @@ -38,6 +38,7 @@ #include "log.h" #include "digest.h" #include "bitmap.h" +#include "utf8.h" #include "krl.h" @@ -97,6 +98,7 @@ struct ssh_krl { char *comment; struct revoked_blob_tree revoked_keys; struct revoked_blob_tree revoked_sha1s; + struct revoked_blob_tree revoked_sha256s; struct revoked_certs_list revoked_certs; }; @@ -121,7 +123,7 @@ blob_cmp(struct revoked_blob *a, struct revoked_blob *b) int r; if (a->len != b->len) { - if ((r = memcmp(a->blob, b->blob, MIN(a->len, b->len))) != 0) + if ((r = memcmp(a->blob, b->blob, MINIMUM(a->len, b->len))) != 0) return r; return a->len > b->len ? 1 : -1; } else @@ -137,6 +139,7 @@ ssh_krl_init(void) return NULL; RB_INIT(&krl->revoked_keys); RB_INIT(&krl->revoked_sha1s); + RB_INIT(&krl->revoked_sha256s); TAILQ_INIT(&krl->revoked_certs); return krl; } @@ -179,6 +182,11 @@ ssh_krl_free(struct ssh_krl *krl) free(rb->blob); free(rb); } + RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha256s, trb) { + RB_REMOVE(revoked_blob_tree, &krl->revoked_sha256s, rb); + free(rb->blob); + free(rb); + } TAILQ_FOREACH_SAFE(rc, &krl->revoked_certs, entry, trc) { TAILQ_REMOVE(&krl->revoked_certs, rc, entry); revoked_certs_free(rc); @@ -409,27 +417,49 @@ ssh_krl_revoke_key_explicit(struct ssh_krl *krl, const struct sshkey *key) return revoke_blob(&krl->revoked_keys, blob, len); } -int -ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const struct sshkey *key) +static int +revoke_by_hash(struct revoked_blob_tree *target, const u_char *p, size_t len) { u_char *blob; - size_t len; int r; - debug3("%s: revoke type %s by sha1", __func__, sshkey_type(key)); - if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1, - &blob, &len)) != 0) + /* need to copy hash, as revoke_blob steals ownership */ + if ((blob = malloc(len)) == NULL) + return SSH_ERR_SYSTEM_ERROR; + memcpy(blob, p, len); + if ((r = revoke_blob(target, blob, len)) != 0) { + free(blob); return r; - return revoke_blob(&krl->revoked_sha1s, blob, len); + } + return 0; +} + +int +ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const u_char *p, size_t len) +{ + debug3("%s: revoke by sha1", __func__); + if (len != 20) + return SSH_ERR_INVALID_FORMAT; + return revoke_by_hash(&krl->revoked_sha1s, p, len); +} + +int +ssh_krl_revoke_key_sha256(struct ssh_krl *krl, const u_char *p, size_t len) +{ + debug3("%s: revoke by sha256", __func__); + if (len != 32) + return SSH_ERR_INVALID_FORMAT; + return revoke_by_hash(&krl->revoked_sha256s, p, len); } int ssh_krl_revoke_key(struct ssh_krl *krl, const struct sshkey *key) { + /* XXX replace with SHA256? */ if (!sshkey_is_cert(key)) - return ssh_krl_revoke_key_sha1(krl, key); + return ssh_krl_revoke_key_explicit(krl, key); - if (sshkey_cert_is_legacy(key) || key->cert->serial == 0) { + if (key->cert->serial == 0) { return ssh_krl_revoke_cert_by_key_id(krl, key->cert->signature_key, key->cert->key_id); @@ -458,9 +488,9 @@ choose_next_state(int current_state, u_int64_t contig, int final, * Avoid unsigned overflows. * The limits are high enough to avoid confusing the calculations. */ - contig = MIN(contig, 1ULL<<31); - last_gap = MIN(last_gap, 1ULL<<31); - next_gap = MIN(next_gap, 1ULL<<31); + contig = MINIMUM(contig, 1ULL<<31); + last_gap = MINIMUM(last_gap, 1ULL<<31); + next_gap = MINIMUM(next_gap, 1ULL<<31); /* * Calculate the cost to switch from the current state to candidates. @@ -486,8 +516,8 @@ choose_next_state(int current_state, u_int64_t contig, int final, /* Estimate base cost in bits of each section type */ cost_list += 64 * contig + (final ? 0 : 8+64); cost_range += (2 * 64) + (final ? 0 : 8+64); - cost_bitmap += last_gap + contig + (final ? 0 : MIN(next_gap, 8+64)); - cost_bitmap_restart += contig + (final ? 0 : MIN(next_gap, 8+64)); + cost_bitmap += last_gap + contig + (final ? 0 : MINIMUM(next_gap, 8+64)); + cost_bitmap_restart += contig + (final ? 0 : MINIMUM(next_gap, 8+64)); /* Convert to byte costs for actual comparison */ cost_list = (cost_list + 7) / 8; @@ -704,7 +734,7 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf) int ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf, - const struct sshkey **sign_keys, u_int nsign_keys) + struct sshkey **sign_keys, u_int nsign_keys) { int r = SSH_ERR_INTERNAL_ERROR; struct revoked_certs *rc; @@ -723,7 +753,7 @@ ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf, if ((r = sshbuf_put(buf, KRL_MAGIC, sizeof(KRL_MAGIC) - 1)) != 0 || (r = sshbuf_put_u32(buf, KRL_FORMAT_VERSION)) != 0 || (r = sshbuf_put_u64(buf, krl->krl_version)) != 0 || - (r = sshbuf_put_u64(buf, krl->generated_date) != 0) || + (r = sshbuf_put_u64(buf, krl->generated_date)) != 0 || (r = sshbuf_put_u64(buf, krl->flags)) != 0 || (r = sshbuf_put_string(buf, NULL, 0)) != 0 || (r = sshbuf_put_cstring(buf, krl->comment)) != 0) @@ -763,6 +793,18 @@ ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf, (r = sshbuf_put_stringb(buf, sect)) != 0) goto out; } + sshbuf_reset(sect); + RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha256s) { + KRL_DBG(("%s: hash len %zu ", __func__, rb->len)); + if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0) + goto out; + } + if (sshbuf_len(sect) != 0) { + if ((r = sshbuf_put_u8(buf, + KRL_SECTION_FINGERPRINT_SHA256)) != 0 || + (r = sshbuf_put_stringb(buf, sect)) != 0) + goto out; + } for (i = 0; i < nsign_keys; i++) { KRL_DBG(("%s: signature key %s", __func__, @@ -772,7 +814,7 @@ ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf, goto out; if ((r = sshkey_sign(sign_keys[i], &sblob, &slen, - sshbuf_ptr(buf), sshbuf_len(buf), 0)) == -1) + sshbuf_ptr(buf), sshbuf_len(buf), NULL, NULL, 0)) != 0) goto out; KRL_DBG(("%s: signature sig len %zu", __func__, slen)); if ((r = sshbuf_put_string(buf, sblob, slen)) != 0) @@ -826,10 +868,8 @@ parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl) goto out; while (sshbuf_len(buf) > 0) { - if (subsect != NULL) { - sshbuf_free(subsect); - subsect = NULL; - } + sshbuf_free(subsect); + subsect = NULL; if ((r = sshbuf_get_u8(buf, &type)) != 0 || (r = sshbuf_froms(buf, &subsect)) != 0) goto out; @@ -917,6 +957,29 @@ parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl) return r; } +static int +blob_section(struct sshbuf *sect, struct revoked_blob_tree *target_tree, + size_t expected_len) +{ + u_char *rdata = NULL; + size_t rlen = 0; + int r; + + while (sshbuf_len(sect) > 0) { + if ((r = sshbuf_get_string(sect, &rdata, &rlen)) != 0) + return r; + if (expected_len != 0 && rlen != expected_len) { + error("%s: bad length", __func__); + free(rdata); + return SSH_ERR_INVALID_FORMAT; + } + if ((r = revoke_blob(target_tree, rdata, rlen)) != 0) { + free(rdata); + return r; + } + } + return 0; +} /* Attempt to parse a KRL, checking its signature (if any) with sign_ca_keys. */ int @@ -928,9 +991,9 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, char timestamp[64]; int r = SSH_ERR_INTERNAL_ERROR, sig_seen; struct sshkey *key = NULL, **ca_used = NULL, **tmp_ca_used; - u_char type, *rdata = NULL; + u_char type; const u_char *blob; - size_t i, j, sig_off, sects_off, rlen, blen, nca_used; + size_t i, j, sig_off, sects_off, blen, nca_used; u_int format_version; nca_used = 0; @@ -1017,7 +1080,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, } /* Check signature over entire KRL up to this point */ if ((r = sshkey_verify(key, blob, blen, - sshbuf_ptr(buf), sshbuf_len(buf) - sig_off, 0)) != 0) + sshbuf_ptr(buf), sig_off, NULL, 0, NULL)) != 0) goto out; /* Check if this key has already signed this KRL */ for (i = 0; i < nca_used; i++) { @@ -1029,7 +1092,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, } } /* Record keys used to sign the KRL */ - tmp_ca_used = reallocarray(ca_used, nca_used + 1, + tmp_ca_used = recallocarray(ca_used, nca_used, nca_used + 1, sizeof(*ca_used)); if (tmp_ca_used == NULL) { r = SSH_ERR_ALLOC_FAIL; @@ -1038,7 +1101,6 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, ca_used = tmp_ca_used; ca_used[nca_used++] = key; key = NULL; - break; } if (sshbuf_len(copy) != 0) { @@ -1059,10 +1121,8 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, if ((r = sshbuf_consume(copy, sects_off)) != 0) goto out; while (sshbuf_len(copy) > 0) { - if (sect != NULL) { - sshbuf_free(sect); - sect = NULL; - } + sshbuf_free(sect); + sect = NULL; if ((r = sshbuf_get_u8(copy, &type)) != 0 || (r = sshbuf_froms(copy, §)) != 0) goto out; @@ -1074,28 +1134,23 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, goto out; break; case KRL_SECTION_EXPLICIT_KEY: + if ((r = blob_section(sect, + &krl->revoked_keys, 0)) != 0) + goto out; + break; case KRL_SECTION_FINGERPRINT_SHA1: - while (sshbuf_len(sect) > 0) { - if ((r = sshbuf_get_string(sect, - &rdata, &rlen)) != 0) - goto out; - if (type == KRL_SECTION_FINGERPRINT_SHA1 && - rlen != 20) { - error("%s: bad SHA1 length", __func__); - r = SSH_ERR_INVALID_FORMAT; - goto out; - } - if ((r = revoke_blob( - type == KRL_SECTION_EXPLICIT_KEY ? - &krl->revoked_keys : &krl->revoked_sha1s, - rdata, rlen)) != 0) - goto out; - rdata = NULL; /* revoke_blob frees rdata */ - } + if ((r = blob_section(sect, + &krl->revoked_sha1s, 20)) != 0) + goto out; + break; + case KRL_SECTION_FINGERPRINT_SHA256: + if ((r = blob_section(sect, + &krl->revoked_sha256s, 32)) != 0) + goto out; break; case KRL_SECTION_SIGNATURE: /* Handled above, but still need to stay in synch */ - sshbuf_reset(sect); + sshbuf_free(sect); sect = NULL; if ((r = sshbuf_skip_string(copy)) != 0) goto out; @@ -1105,7 +1160,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, r = SSH_ERR_INVALID_FORMAT; goto out; } - if (sshbuf_len(sect) > 0) { + if (sect != NULL && sshbuf_len(sect) > 0) { error("KRL section contains unparsed data"); r = SSH_ERR_INVALID_FORMAT; goto out; @@ -1156,7 +1211,6 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp, for (i = 0; i < nca_used; i++) sshkey_free(ca_used[i]); free(ca_used); - free(rdata); sshkey_free(key); sshbuf_free(copy); sshbuf_free(sect); @@ -1180,10 +1234,10 @@ is_cert_revoked(const struct sshkey *key, struct revoked_certs *rc) } /* - * Legacy cert formats lack serial numbers. Zero serials numbers - * are ignored (it's the default when the CA doesn't specify one). + * Zero serials numbers are ignored (it's the default when the + * CA doesn't specify one). */ - if (sshkey_cert_is_legacy(key) || key->cert->serial == 0) + if (key->cert->serial == 0) return 0; memset(&rs, 0, sizeof(rs)); @@ -1216,6 +1270,16 @@ is_key_revoked(struct ssh_krl *krl, const struct sshkey *key) KRL_DBG(("%s: revoked by key SHA1", __func__)); return SSH_ERR_KEY_REVOKED; } + memset(&rb, 0, sizeof(rb)); + if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA256, + &rb.blob, &rb.len)) != 0) + return r; + erb = RB_FIND(revoked_blob_tree, &krl->revoked_sha256s, &rb); + free(rb.blob); + if (erb != NULL) { + KRL_DBG(("%s: revoked by key SHA256", __func__)); + return SSH_ERR_KEY_REVOKED; + } /* Next, explicit keys */ memset(&rb, 0, sizeof(rb)); @@ -1273,19 +1337,11 @@ ssh_krl_file_contains_key(const char *path, const struct sshkey *key) { struct sshbuf *krlbuf = NULL; struct ssh_krl *krl = NULL; - int oerrno = 0, r, fd; + int oerrno = 0, r; if (path == NULL) return 0; - - if ((krlbuf = sshbuf_new()) == NULL) - return SSH_ERR_ALLOC_FAIL; - if ((fd = open(path, O_RDONLY)) == -1) { - r = SSH_ERR_SYSTEM_ERROR; - oerrno = errno; - goto out; - } - if ((r = sshkey_load_file(fd, krlbuf)) != 0) { + if ((r = sshbuf_load_file(path, &krlbuf)) != 0) { oerrno = errno; goto out; } @@ -1294,10 +1350,103 @@ ssh_krl_file_contains_key(const char *path, const struct sshkey *key) debug2("%s: checking KRL %s", __func__, path); r = ssh_krl_check_key(krl, key); out: - close(fd); sshbuf_free(krlbuf); ssh_krl_free(krl); if (r != 0) errno = oerrno; return r; } + +int +krl_dump(struct ssh_krl *krl, FILE *f) +{ + struct sshkey *key = NULL; + struct revoked_blob *rb; + struct revoked_certs *rc; + struct revoked_serial *rs; + struct revoked_key_id *rki; + int r, ret = 0; + char *fp, timestamp[64]; + + /* Try to print in a KRL spec-compatible format */ + format_timestamp(krl->generated_date, timestamp, sizeof(timestamp)); + fprintf(f, "# KRL version %llu\n", + (unsigned long long)krl->krl_version); + fprintf(f, "# Generated at %s\n", timestamp); + if (krl->comment != NULL && *krl->comment != '\0') { + r = INT_MAX; + asmprintf(&fp, INT_MAX, &r, "%s", krl->comment); + fprintf(f, "# Comment: %s\n", fp); + free(fp); + } + fputc('\n', f); + + RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_keys) { + if ((r = sshkey_from_blob(rb->blob, rb->len, &key)) != 0) { + ret = SSH_ERR_INVALID_FORMAT; + error("Parse key in KRL: %s", ssh_err(r)); + continue; + } + if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT, + SSH_FP_DEFAULT)) == NULL) { + ret = SSH_ERR_INVALID_FORMAT; + error("sshkey_fingerprint failed"); + continue; + } + fprintf(f, "hash: SHA256:%s # %s\n", fp, sshkey_ssh_name(key)); + free(fp); + free(key); + } + RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha256s) { + fp = tohex(rb->blob, rb->len); + fprintf(f, "hash: SHA256:%s\n", fp); + free(fp); + } + RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha1s) { + /* + * There is not KRL spec keyword for raw SHA1 hashes, so + * print them as comments. + */ + fp = tohex(rb->blob, rb->len); + fprintf(f, "# hash SHA1:%s\n", fp); + free(fp); + } + + TAILQ_FOREACH(rc, &krl->revoked_certs, entry) { + fputc('\n', f); + if (rc->ca_key == NULL) + fprintf(f, "# Wildcard CA\n"); + else { + if ((fp = sshkey_fingerprint(rc->ca_key, + SSH_FP_HASH_DEFAULT, SSH_FP_DEFAULT)) == NULL) { + ret = SSH_ERR_INVALID_FORMAT; + error("sshkey_fingerprint failed"); + continue; + } + fprintf(f, "# CA key %s %s\n", + sshkey_ssh_name(rc->ca_key), fp); + free(fp); + } + RB_FOREACH(rs, revoked_serial_tree, &rc->revoked_serials) { + if (rs->lo == rs->hi) { + fprintf(f, "serial: %llu\n", + (unsigned long long)rs->lo); + } else { + fprintf(f, "serial: %llu-%llu\n", + (unsigned long long)rs->lo, + (unsigned long long)rs->hi); + } + } + RB_FOREACH(rki, revoked_key_id_tree, &rc->revoked_key_ids) { + /* + * We don't want key IDs with embedded newlines to + * mess up the display. + */ + r = INT_MAX; + asmprintf(&fp, INT_MAX, &r, "%s", rki->key_id); + fprintf(f, "id: %s\n", fp); + free(fp); + } + } + return ret; +} |