upstream: refactor sshkey_read() to make it a little more, err,

readable. ok markus

OpenBSD-Commit-ID: 2e9247b5762fdac3b6335dc606d3822121714c28

1 files changed, 135 insertions, 113 deletions

diff --git a/sshkey.c b/sshkey.c
index d8ee70ca0..b7c392bef 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.62 2018/02/23 15:58:38 markus Exp $ */
+/* $OpenBSD: sshkey.c,v 1.63 2018/03/02 02:08:03 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -1215,22 +1215,37 @@ sshkey_fingerprint(const struct sshkey *k, int dgst_alg,
         return retval;
 }
 
+static int
+peek_type_nid(const char *s, size_t l, int *nid)
+{
+        const struct keytype *kt;
+
+        for (kt = keytypes; kt->type != -1; kt++) {
+                if (kt->name == NULL || strlen(kt->name) != l)
+                        continue;
+                if (memcmp(s, kt->name, l) == 0) {
+                        *nid = -1;
+                        if (kt->type == KEY_ECDSA || kt->type == KEY_ECDSA_CERT)
+                                *nid = kt->nid;
+                        return kt->type;
+                }
+        }
+        return KEY_UNSPEC;
+}
 
-/* returns 0 ok, and < 0 error */
+/* XXX this can now be made const char * */
 int
 sshkey_read(struct sshkey *ret, char **cpp)
 {
         struct sshkey *k;
-        int retval = SSH_ERR_INVALID_FORMAT;
-        char *ep, *cp, *space;
+        char *cp, *blobcopy;
+        size_t space;
         int r, type, curve_nid = -1;
         struct sshbuf *blob;
 
         if (ret == NULL)
                 return SSH_ERR_INVALID_ARGUMENT;
 
-        cp = *cpp;
-
         switch (ret->type) {
         case KEY_UNSPEC:
         case KEY_RSA:
@@ -1245,136 +1260,143 @@ sshkey_read(struct sshkey *ret, char **cpp)
         case KEY_XMSS:
         case KEY_XMSS_CERT:
 #endif /* WITH_XMSS */
-                space = strchr(cp, ' ');
-                if (space == NULL)
-                        return SSH_ERR_INVALID_FORMAT;
-                *space = '\0';
-                type = sshkey_type_from_name(cp);
-                if (sshkey_type_plain(type) == KEY_ECDSA &&
-                    (curve_nid = sshkey_ecdsa_nid_from_name(cp)) == -1)
-                        return SSH_ERR_EC_CURVE_INVALID;
-                *space = ' ';
-                if (type == KEY_UNSPEC)
-                        return SSH_ERR_INVALID_FORMAT;
-                cp = space+1;
-                if (*cp == '\0')
-                        return SSH_ERR_INVALID_FORMAT;
-                if (ret->type != KEY_UNSPEC && ret->type != type)
-                        return SSH_ERR_KEY_TYPE_MISMATCH;
-                if ((blob = sshbuf_new()) == NULL)
-                        return SSH_ERR_ALLOC_FAIL;
-                /* trim comment */
-                space = strchr(cp, ' ');
-                if (space) {
-                        /* advance 'space': skip whitespace */
-                        *space++ = '\0';
-                        while (*space == ' ' || *space == '\t')
-                                space++;
-                        ep = space;
-                } else
-                        ep = cp + strlen(cp);
-                if ((r = sshbuf_b64tod(blob, cp)) != 0) {
-                        sshbuf_free(blob);
-                        return r;
-                }
-                if ((r = sshkey_from_blob(sshbuf_ptr(blob),
-                    sshbuf_len(blob), &k)) != 0) {
-                        sshbuf_free(blob);
-                        return r;
-                }
+                break; /* ok */
+        default:
+                return SSH_ERR_INVALID_ARGUMENT;
+        }
+
+        /* Decode type */
+        cp = *cpp;
+        space = strcspn(cp, " \t");
+        if (space == strlen(cp))
+                return SSH_ERR_INVALID_FORMAT;
+        if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC)
+                return SSH_ERR_INVALID_FORMAT;
+
+        /* skip whitespace */
+        for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
+                ;
+        if (*cp == '\0')
+                return SSH_ERR_INVALID_FORMAT;
+        if (ret->type != KEY_UNSPEC && ret->type != type)
+                return SSH_ERR_KEY_TYPE_MISMATCH;
+        if ((blob = sshbuf_new()) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+
+        /* find end of keyblob and decode */
+        space = strcspn(cp, " \t");
+        if ((blobcopy = strndup(cp, space)) == NULL) {
                 sshbuf_free(blob);
-                if (k->type != type) {
-                        sshkey_free(k);
-                        return SSH_ERR_KEY_TYPE_MISMATCH;
-                }
-                if (sshkey_type_plain(type) == KEY_ECDSA &&
-                    curve_nid != k->ecdsa_nid) {
+                return SSH_ERR_ALLOC_FAIL;
+        }
+        if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) {
+                free(blobcopy);
+                sshbuf_free(blob);
+                return r;
+        }
+        free(blobcopy);
+        if ((r = sshkey_fromb(blob, &k)) != 0) {
+                sshbuf_free(blob);
+                return r;
+        }
+        sshbuf_free(blob);
+
+        /* skip whitespace and leave cp at start of comment */
+        for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
+                ;
+
+        /* ensure type of blob matches type at start of line */
+        if (k->type != type) {
+                sshkey_free(k);
+                return SSH_ERR_KEY_TYPE_MISMATCH;
+        }
+        if (sshkey_type_plain(type) == KEY_ECDSA && curve_nid != k->ecdsa_nid) {
+                sshkey_free(k);
+                return SSH_ERR_EC_CURVE_MISMATCH;
+        }
+
+        /* Fill in ret from parsed key */
+        ret->type = type;
+        if (sshkey_is_cert(ret)) {
+                if (!sshkey_is_cert(k)) {
                         sshkey_free(k);
-                        return SSH_ERR_EC_CURVE_MISMATCH;
-                }
-                ret->type = type;
-                if (sshkey_is_cert(ret)) {
-                        if (!sshkey_is_cert(k)) {
-                                sshkey_free(k);
-                                return SSH_ERR_EXPECTED_CERT;
-                        }
-                        if (ret->cert != NULL)
-                                cert_free(ret->cert);
-                        ret->cert = k->cert;
-                        k->cert = NULL;
+                        return SSH_ERR_EXPECTED_CERT;
                 }
-                switch (sshkey_type_plain(ret->type)) {
+                if (ret->cert != NULL)
+                        cert_free(ret->cert);
+                ret->cert = k->cert;
+                k->cert = NULL;
+        }
+        switch (sshkey_type_plain(ret->type)) {
 #ifdef WITH_OPENSSL
-                case KEY_RSA:
-                        RSA_free(ret->rsa);
-                        ret->rsa = k->rsa;
-                        k->rsa = NULL;
+        case KEY_RSA:
+                RSA_free(ret->rsa);
+                ret->rsa = k->rsa;
+                k->rsa = NULL;
 #ifdef DEBUG_PK
-                        RSA_print_fp(stderr, ret->rsa, 8);
+                RSA_print_fp(stderr, ret->rsa, 8);
 #endif
-                        break;
-                case KEY_DSA:
-                        DSA_free(ret->dsa);
-                        ret->dsa = k->dsa;
-                        k->dsa = NULL;
+                break;
+        case KEY_DSA:
+                DSA_free(ret->dsa);
+                ret->dsa = k->dsa;
+                k->dsa = NULL;
 #ifdef DEBUG_PK
-                        DSA_print_fp(stderr, ret->dsa, 8);
+                DSA_print_fp(stderr, ret->dsa, 8);
 #endif
-                        break;
+                break;
 # ifdef OPENSSL_HAS_ECC
-                case KEY_ECDSA:
-                        EC_KEY_free(ret->ecdsa);
-                        ret->ecdsa = k->ecdsa;
-                        ret->ecdsa_nid = k->ecdsa_nid;
-                        k->ecdsa = NULL;
-                        k->ecdsa_nid = -1;
+        case KEY_ECDSA:
+                EC_KEY_free(ret->ecdsa);
+                ret->ecdsa = k->ecdsa;
+                ret->ecdsa_nid = k->ecdsa_nid;
+                k->ecdsa = NULL;
+                k->ecdsa_nid = -1;
 #ifdef DEBUG_PK
-                        sshkey_dump_ec_key(ret->ecdsa);
+                sshkey_dump_ec_key(ret->ecdsa);
 #endif
-                        break;
+                break;
 # endif /* OPENSSL_HAS_ECC */
 #endif /* WITH_OPENSSL */
-                case KEY_ED25519:
-                        freezero(ret->ed25519_pk, ED25519_PK_SZ);
-                        ret->ed25519_pk = k->ed25519_pk;
-                        k->ed25519_pk = NULL;
+        case KEY_ED25519:
+                freezero(ret->ed25519_pk, ED25519_PK_SZ);
+                ret->ed25519_pk = k->ed25519_pk;
+                k->ed25519_pk = NULL;
 #ifdef DEBUG_PK
-                        /* XXX */
+                /* XXX */
 #endif
-                        break;
+                break;
 #ifdef WITH_XMSS
-                case KEY_XMSS:
-                        free(ret->xmss_pk);
-                        ret->xmss_pk = k->xmss_pk;
-                        k->xmss_pk = NULL;
-                        free(ret->xmss_state);
-                        ret->xmss_state = k->xmss_state;
-                        k->xmss_state = NULL;
-                        free(ret->xmss_name);
-                        ret->xmss_name = k->xmss_name;
-                        k->xmss_name = NULL;
-                        free(ret->xmss_filename);
-                        ret->xmss_filename = k->xmss_filename;
-                        k->xmss_filename = NULL;
+        case KEY_XMSS:
+                free(ret->xmss_pk);
+                ret->xmss_pk = k->xmss_pk;
+                k->xmss_pk = NULL;
+                free(ret->xmss_state);
+                ret->xmss_state = k->xmss_state;
+                k->xmss_state = NULL;
+                free(ret->xmss_name);
+                ret->xmss_name = k->xmss_name;
+                k->xmss_name = NULL;
+                free(ret->xmss_filename);
+                ret->xmss_filename = k->xmss_filename;
+                k->xmss_filename = NULL;
 #ifdef DEBUG_PK
-                        /* XXX */
+                /* XXX */
 #endif
-                        break;
-#endif /* WITH_XMSS */
-                }
-                *cpp = ep;
-                retval = 0;
-/*XXXX*/
-                sshkey_free(k);
-                if (retval != 0)
-                        break;
                 break;
+#endif /* WITH_XMSS */
         default:
-                return SSH_ERR_INVALID_ARGUMENT;
+                sshkey_free(k);
+                return SSH_ERR_INTERNAL_ERROR;
         }
-        return retval;
+        sshkey_free(k);
+
+        /* success */
+        *cpp = cp;
+        return 0;
 }
 
+
 int
 sshkey_to_base64(const struct sshkey *key, char **b64p)
 {