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/* $Id: keyproc.c,v 1.9 2017/03/26 18:41:02 deraadt Exp $ */ |
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/* |
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* Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/stat.h> |
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#include <err.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <openssl/pem.h> |
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#include <openssl/err.h> |
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#include <openssl/rand.h> |
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#include <openssl/x509.h> |
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#include <openssl/x509v3.h> |
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#include "extern.h" |
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#include "rsa.h" |
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/* |
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* This was lifted more or less directly from demos/x509/mkreq.c of the |
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* OpenSSL source code. |
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*/ |
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static int |
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add_ext(STACK_OF(X509_EXTENSION) *sk, int nid, const char *value) |
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{ |
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X509_EXTENSION *ex; |
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char *cp; |
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/* |
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* XXX: I don't like this at all. |
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* There's no documentation for X509V3_EXT_conf_nid, so I'm not |
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* sure if the "value" parameter is ever written to, touched, |
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* etc. |
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* The 'official' examples suggest not (they use a string |
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* literal as the input), but to be safe, I'm doing an |
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* allocation here and just letting it go. |
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* This leaks memory, but bounded to the number of SANs. |
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*/ |
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if ((cp = strdup(value)) == NULL) { |
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warn("strdup"); |
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return (0); |
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} |
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ex = X509V3_EXT_conf_nid(NULL, NULL, nid, cp); |
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if (ex == NULL) { |
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warnx("X509V3_EXT_conf_nid"); |
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free(cp); |
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return (0); |
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} |
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sk_X509_EXTENSION_push(sk, ex); |
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return (1); |
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} |
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/* |
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* Create an X509 certificate from the private key we have on file. |
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* To do this, we first open the key file, then jail ourselves. |
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* We then use the crypto library to create the certificate within the |
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* jail and, on success, ship it to "netsock" as an X509 request. |
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*/ |
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int |
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keyproc(int netsock, const char *keyfile, |
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const char **alts, size_t altsz, int newkey) |
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{ |
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char *der64 = NULL, *der = NULL, *dercp; |
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char *sans = NULL, *san = NULL; |
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FILE *f; |
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size_t i, sansz; |
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void *pp; |
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EVP_PKEY *pkey = NULL; |
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X509_REQ *x = NULL; |
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X509_NAME *name = NULL; |
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int len, rc = 0, cc, nid; |
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mode_t prev; |
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STACK_OF(X509_EXTENSION) *exts = NULL; |
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/* |
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* First, open our private key file read-only or write-only if |
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* we're creating from scratch. |
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* Set our umask to be maximally restrictive. |
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*/ |
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prev = umask((S_IWUSR | S_IXUSR) | S_IRWXG | S_IRWXO); |
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f = fopen(keyfile, newkey ? "wx" : "r"); |
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umask(prev); |
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if (f == NULL) { |
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warn("%s", keyfile); |
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goto out; |
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} |
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/* File-system, user, and sandbox jail. */ |
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ERR_load_crypto_strings(); |
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if (pledge("stdio flock rpath cpath wpath", NULL) == -1) { |
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warn("pledge"); |
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goto out; |
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} |
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if (newkey) { |
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if ((pkey = rsa_key_create(f, keyfile)) == NULL) |
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goto out; |
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dodbg("%s: generated RSA domain key", keyfile); |
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} else { |
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if ((pkey = rsa_key_load(f, keyfile)) == NULL) |
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goto out; |
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doddbg("%s: loaded RSA domain key", keyfile); |
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} |
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fclose(f); |
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f = NULL; |
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/* |
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* Generate our certificate from the EVP public key. |
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* Then set it as the X509 requester's key. |
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*/ |
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if ((x = X509_REQ_new()) == NULL) { |
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warnx("X509_new"); |
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goto out; |
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} else if (!X509_REQ_set_pubkey(x, pkey)) { |
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warnx("X509_set_pubkey"); |
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goto out; |
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} |
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/* Now specify the common name that we'll request. */ |
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if ((name = X509_NAME_new()) == NULL) { |
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warnx("X509_NAME_new"); |
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goto out; |
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} else if (!X509_NAME_add_entry_by_txt(name, "CN", |
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MBSTRING_ASC, (u_char *)alts[0], -1, -1, 0)) { |
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warnx("X509_NAME_add_entry_by_txt: CN=%s", alts[0]); |
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goto out; |
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} else if (!X509_REQ_set_subject_name(x, name)) { |
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warnx("X509_req_set_issuer_name"); |
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goto out; |
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} |
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/* |
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* Now add the SAN extensions. |
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* This was lifted more or less directly from demos/x509/mkreq.c |
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* of the OpenSSL source code. |
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* (The zeroth altname is the domain name.) |
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* TODO: is this the best way of doing this? |
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*/ |
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if (altsz > 1) { |
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nid = NID_subject_alt_name; |
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if ((exts = sk_X509_EXTENSION_new_null()) == NULL) { |
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warnx("sk_X509_EXTENSION_new_null"); |
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goto out; |
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} |
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/* Initialise to empty string. */ |
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if ((sans = strdup("")) == NULL) { |
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warn("strdup"); |
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goto out; |
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} |
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sansz = strlen(sans) + 1; |
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/* |
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* For each SAN entry, append it to the string. |
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* We need a single SAN entry for all of the SAN |
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* domains: NOT an entry per domain! |
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*/ |
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for (i = 1; i < altsz; i++) { |
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cc = asprintf(&san, "%sDNS:%s", |
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i > 1 ? "," : "", alts[i]); |
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if (cc == -1) { |
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warn("asprintf"); |
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goto out; |
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} |
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pp = recallocarray(sans, sansz, sansz + strlen(san), 1); |
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if (pp == NULL) { |
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warn("recallocarray"); |
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goto out; |
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} |
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sans = pp; |
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sansz += strlen(san); |
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strlcat(sans, san, sansz); |
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free(san); |
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san = NULL; |
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} |
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if (!add_ext(exts, nid, sans)) { |
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warnx("add_ext"); |
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goto out; |
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} else if (!X509_REQ_add_extensions(x, exts)) { |
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warnx("X509_REQ_add_extensions"); |
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goto out; |
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} |
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sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free); |
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} |
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/* Sign the X509 request using SHA256. */ |
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if (!X509_REQ_sign(x, pkey, EVP_sha256())) { |
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warnx("X509_sign"); |
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goto out; |
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} |
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/* Now, serialise to DER, then base64. */ |
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if ((len = i2d_X509_REQ(x, NULL)) < 0) { |
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warnx("i2d_X509"); |
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goto out; |
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} else if ((der = dercp = malloc(len)) == NULL) { |
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warn("malloc"); |
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goto out; |
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} else if (len != i2d_X509_REQ(x, (u_char **)&dercp)) { |
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warnx("i2d_X509"); |
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goto out; |
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} else if ((der64 = base64buf_url(der, len)) == NULL) { |
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warnx("base64buf_url"); |
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goto out; |
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} |
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/* |
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* Write that we're ready, then write. |
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* We ignore reader-closed failure, as we're just going to roll |
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* into the exit case anyway. |
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*/ |
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if (writeop(netsock, COMM_KEY_STAT, KEY_READY) < 0) |
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goto out; |
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if (writestr(netsock, COMM_CERT, der64) < 0) |
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goto out; |
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rc = 1; |
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out: |
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close(netsock); |
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if (f != NULL) |
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fclose(f); |
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free(der); |
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free(der64); |
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free(sans); |
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free(san); |
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if (x != NULL) |
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X509_REQ_free(x); |
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if (name != NULL) |
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X509_NAME_free(name); |
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if (pkey != NULL) |
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EVP_PKEY_free(pkey); |
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ERR_print_errors_fp(stderr); |
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ERR_free_strings(); |
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return (rc); |
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} |