cmake: reindent the file
[project/ucert.git] / ucert.c
diff --git a/ucert.c b/ucert.c
index 54ec2233cbe57713439dccbcee26f7d0bdb24bdf..8503eeb26cd85efd04cc7bc00b02617e6ba773c3 100644 (file)
--- a/ucert.c
+++ b/ucert.c
 
 #include <json-c/json.h>
 #include <libubox/blob.h>
+#include <libubox/utils.h>
 #include <libubox/list.h>
 #include <libubox/vlist.h>
 #include <libubox/blobmsg_json.h>
 
+#include "usign.h"
+
+#define CERT_BUF_LEN 4096
+
 static enum {
        CMD_APPEND,
        CMD_DUMP,
@@ -42,112 +47,680 @@ static enum {
 } cmd = CMD_NONE;
 
 static bool quiet;
+#ifndef UCERT_STRIP_MESSAGES
+#define DPRINTF(format, ...)                                                                   \
+       do {                                                                                    \
+               if (!quiet)                                                                     \
+                       fprintf(stderr, "%s(%d): " format, __func__, __LINE__, ## __VA_ARGS__); \
+       } while (0)
+#else
+#define DPRINTF(format, ...) do { } while (0)
+#endif
 
-static int cert_append(const char *certfile, const char *pubkeyfile, const char *sigfile) {
-       fprintf(stderr, "not implemented\n");
-       return 1;
+/*
+ * ucert structure
+ * |               BLOB                    |
+ * |    SIGNATURE    |       PAYLOAD       |
+ * |                 |[ BLOBMSG CONTAINER ]|
+ * |                 |[[T,i,v,e,f,pubkey ]]|
+ */
+enum cert_attr {
+       CERT_ATTR_SIGNATURE,
+       CERT_ATTR_PAYLOAD,
+       CERT_ATTR_MAX
+};
+
+static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
+       [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
+       [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
+};
+
+enum cert_cont_attr {
+       CERT_CT_ATTR_PAYLOAD,
+       CERT_CT_ATTR_MAX
+};
+
+static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
+       [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
+};
+
+enum cert_payload_attr {
+       CERT_PL_ATTR_CERTTYPE,
+       CERT_PL_ATTR_CERTID,
+       CERT_PL_ATTR_VALIDFROMTIME,
+       CERT_PL_ATTR_EXPIRETIME,
+       CERT_PL_ATTR_PUBKEY,
+       CERT_PL_ATTR_KEY_FINGERPRINT,
+       CERT_PL_ATTR_MAX
+};
+
+enum certtype_id {
+       CERTTYPE_UNSPEC,
+       CERTTYPE_AUTH,
+       CERTTYPE_REVOKE
+};
+
+static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
+       [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
+       [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
+       [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
+       [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
+       [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
+       [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
+};
+
+/* list to store certificate chain at runtime */
+struct cert_object {
+       struct list_head list;
+       struct blob_attr *cert[CERT_ATTR_MAX];
+};
+
+/* write buffer to file */
+static int write_file(const char *filename, void *buf, size_t len, bool append) {
+       FILE *f;
+       size_t outlen;
+
+       f = fopen(filename, append?"a":"w");
+       if (!f)
+               return 1;
+
+       outlen = fwrite(buf, 1, len, f);
+       fclose(f);
+       return (outlen == len);
+}
+
+/* load certfile into list */
+static int cert_load(const char *certfile, struct list_head *chain) {
+       FILE *f;
+       struct blob_attr *certtb[CERT_ATTR_MAX];
+       struct blob_attr *bufpt;
+       struct cert_object *cobj;
+       char filebuf[CERT_BUF_LEN];
+       int ret = 0, pret = 0;
+       size_t len, pos = 0;
+
+       f = fopen(certfile, "r");
+       if (!f)
+               return 1;
+
+       len = fread(&filebuf, 1, CERT_BUF_LEN - 1, f);
+       if (len < 64)
+               return 1;
+
+       ret = ferror(f) || !feof(f);
+       fclose(f);
+       if (ret)
+               return 1;
+
+       bufpt = (struct blob_attr *)filebuf;
+       do {
+               pret = blob_parse(bufpt, certtb, cert_policy, CERT_ATTR_MAX);
+               if (pret <= 0)
+                       /* no attributes found */
+                       break;
+
+               if (pos + blob_pad_len(bufpt) > len)
+                       /* blob exceeds filebuffer */
+                       break;
+               else
+                       pos += blob_pad_len(bufpt);
+
+               if (!certtb[CERT_ATTR_SIGNATURE])
+                       /* no signature -> drop */
+                       break;
+
+               cobj = calloc(1, sizeof(*cobj));
+               cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
+               if (certtb[CERT_ATTR_PAYLOAD])
+                       cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
+
+               list_add_tail(&cobj->list, chain);
+               ret += pret;
+       /* repeat parsing while there is still enough remaining data in buffer */
+       } while(len > pos + sizeof(struct blob_attr) && (bufpt = blob_next(bufpt)));
+
+       return (ret <= 0);
+}
+
+#ifdef UCERT_FULL
+/* append signature to certfile */
+static int cert_append(const char *certfile, const char *sigfile) {
+       FILE *fs;
+       char filebuf[CERT_BUF_LEN];
+       struct blob_buf sigbuf = {0};
+       int len;
+       int ret;
+
+       fs = fopen(sigfile, "r");
+       if (!fs)
+               return 1;
+
+       len = fread(&filebuf, 1, CERT_BUF_LEN - 1, fs);
+       ret = ferror(fs) || !feof(fs) || (len < 64);
+       fclose(fs);
+       if (ret)
+               return 1;
+
+       blob_buf_init(&sigbuf, 0);
+       blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
+       ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
+       blob_buf_free(&sigbuf);
+       return ret;
+}
+#endif
+
+/* verify the signature of a single chain element */
+static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
+                      const char *pubkeyfile, const char *pubkeydir) {
+       int i;
+       char msgfname[256], sigfname[256];
+       int ret;
+       char tmpdir[] = "/tmp/ucert-XXXXXX";
+
+       if (mkdtemp(tmpdir) == NULL)
+               return errno;
+
+       snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
+       snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
+
+       for (i = 0; i < CERT_ATTR_MAX; i++) {
+               struct blob_attr *v = cert[i];
+
+               if (!v)
+                       break;
+
+               switch(cert_policy[i].type) {
+               case BLOB_ATTR_BINARY:
+                       write_file(sigfname, blob_data(v), blob_len(v), false);
+                       break;
+               case BLOB_ATTR_NESTED:
+                       write_file(msgfname, blob_data(v), blob_len(v), false);
+                       break;
+               }
+       }
+
+       ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
+
+       unlink(msgfname);
+       unlink(sigfname);
+       rmdir(tmpdir);
+
+       return ret;
+}
+
+/* verify cert chain (and message) */
+static int chain_verify(const char *msgfile, const char *pubkeyfile,
+                       const char *pubkeydir, struct list_head *chain) {
+       struct cert_object *cobj;
+       struct blob_attr *containertb[CERT_CT_ATTR_MAX];
+       struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
+       char tmpdir[] = "/tmp/ucert-XXXXXX";
+       char chainedpubkey[256] = {0};
+       char chainedfp[17] = {0};
+       char extsigfile[256] = {0};
+       int ret = 1;
+       int checkmsg = 0;
+       struct timeval tv;
+
+       if (mkdtemp(tmpdir) == NULL)
+               return errno;
+
+       if (msgfile)
+               checkmsg = -1;
+
+       gettimeofday(&tv, NULL);
+
+       list_for_each_entry(cobj, chain, list) {
+               /* blob has payload, verify that using signature */
+               if (cobj->cert[CERT_ATTR_PAYLOAD]) {
+                       time_t validfrom;
+                       time_t expiresat;
+                       uint32_t certtype;
+
+                       ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
+                       if (ret)
+                               goto clean_and_return;
+
+                       blobmsg_parse(cert_cont_policy,
+                                     ARRAY_SIZE(cert_cont_policy),
+                                     containertb,
+                                     blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
+                                     blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
+                       if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
+                               ret = 1;
+                               DPRINTF("no ucert in signed payload\n");
+                               goto clean_and_return;
+                       }
+                       blobmsg_parse(cert_payload_policy,
+                                     ARRAY_SIZE(cert_payload_policy),
+                                     payloadtb,
+                                     blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
+                                     blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
+
+                       if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
+                           !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
+                           !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
+                           !payloadtb[CERT_PL_ATTR_PUBKEY]) {
+                               ret = 1;
+                               DPRINTF("missing mandatory ucert attributes\n");
+                               goto clean_and_return;
+                       }
+                       certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
+                       validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
+                       expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
+
+                       if (certtype != CERTTYPE_AUTH) {
+                               ret = 2;
+                               DPRINTF("wrong certificate type\n");
+                               goto clean_and_return;
+                       }
+
+                       if (tv.tv_sec < validfrom ||
+                           tv.tv_sec >= expiresat) {
+                               ret = 3;
+                               DPRINTF("certificate expired\n");
+                               goto clean_and_return;
+                       }
+
+                       snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
+                       write_file(chainedpubkey,
+                                  blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
+                                  blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
+                                  false);
+
+                       if (usign_f_pubkey(chainedfp, chainedpubkey)) {
+                               DPRINTF("cannot get fingerprint for chained key\n");
+                               ret = 2;
+                               goto clean_and_return;
+                       }
+                       if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
+                               DPRINTF("key %s has been revoked!\n", chainedfp);
+                               ret = 4;
+                               goto clean_and_return;
+                       }
+               } else {
+               /* blob doesn't have payload, verify message using signature */
+                       if (msgfile) {
+                               snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
+                               write_file(extsigfile,
+                                          blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
+                                          blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
+                                          false);
+                               checkmsg = ret = usign_v(msgfile,
+                                             chainedpubkey[0]?chainedpubkey:pubkeyfile,
+                                             pubkeydir, extsigfile, quiet);
+                               unlink(extsigfile);
+                       } else {
+                               DPRINTF("stray trailing signature without anything to verify!\n");
+                               ret = 1;
+                       };
+               }
+       }
+
+       if (checkmsg == -1)
+               DPRINTF("missing signature to verify message!\n");
+
+clean_and_return:
+       if (chainedpubkey[0])
+               unlink(chainedpubkey);
+       rmdir(tmpdir);
+       return ret | checkmsg;
+}
+
+#ifdef UCERT_FULL
+/* dump single chain element to console */
+static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
+       int i;
+
+       for (i = 0; i < CERT_ATTR_MAX; i++) {
+               struct blob_attr *v = cert[i];
+
+               if (!v)
+                       continue;
+
+               switch(cert_policy[i].type) {
+               case BLOB_ATTR_BINARY:
+                       fprintf(stdout, "signature:\n---\n%s---\n", (char *) blob_data(v));
+                       break;
+               case BLOB_ATTR_NESTED:
+                       fprintf(stdout, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v), false, 0));
+                       break;
+               }
+       }
 }
 
+/* dump certfile to console */
 static int cert_dump(const char *certfile) {
-       fprintf(stderr, "not implemented\n");
-       return 1;
+       struct cert_object *cobj;
+       static LIST_HEAD(certchain);
+       unsigned int count = 0;
+
+       if (cert_load(certfile, &certchain)) {
+               DPRINTF("cannot parse cert\n");
+               return 1;
+       }
+
+       list_for_each_entry(cobj, &certchain, list) {
+               fprintf(stdout, "=== CHAIN ELEMENT %02u ===\n", ++count);
+               cert_dump_blob(cobj->cert);
+       }
+
+       return 0;
 }
 
+/* issue an auth certificate for pubkey */
 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
-       fprintf(stderr, "not implemented\n");
-       return 1;
+       struct blob_buf payloadbuf = {0};
+       struct blob_buf certbuf = {0};
+       struct timeval tv;
+       int pklen, siglen;
+       int revoker = 1;
+       void *c;
+       FILE *pkf, *sigf;
+       char pkb[512];
+       char sigb[1024];
+       char fname[256], sfname[256];
+       char pkfp[17];
+       char tmpdir[] = "/tmp/ucert-XXXXXX";
+
+       pkf = fopen(pubkeyfile, "r");
+       if (!pkf)
+               return -1;
+
+       pklen = fread(pkb, 1, 512, pkf);
+       pkb[pklen] = '\0';
+
+       if (pklen < 32)
+               return -1;
+
+       fclose(pkf);
+
+       if (usign_f_pubkey(pkfp, pubkeyfile))
+               return -1;
+
+       gettimeofday(&tv, NULL);
+
+       if (mkdtemp(tmpdir) == NULL)
+               return errno;
+
+       while (revoker >= 0) {
+               blob_buf_init(&payloadbuf, 0);
+               c = blobmsg_open_table(&payloadbuf, "ucert");
+               blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
+               blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
+               if (!revoker) {
+                       blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
+                       blobmsg_add_string(&payloadbuf, "pubkey", pkb);
+               } else {
+                       blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
+               }
+
+               blobmsg_close_table(&payloadbuf, c);
+
+               snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
+               write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
+
+               snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
+               if (usign_s(fname, seckeyfile, sfname, quiet))
+                       return 1;
+
+               sigf = fopen(sfname, "r");
+               if (!sigf)
+                       return 1;
+
+               siglen = fread(sigb, 1, 1024, sigf);
+               if (siglen < 1)
+                       return 1;
+
+               sigb[siglen] = '\0';
+               fclose(sigf);
+
+               unlink(fname);
+               unlink(sfname);
+
+               blob_buf_init(&certbuf, 0);
+               blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
+               blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
+               snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
+               write_file(fname, certbuf.head, blob_raw_len(certbuf.head), true);
+               blob_buf_free(&certbuf);
+               blob_buf_free(&payloadbuf);
+
+               revoker--;
+       }
+
+       rmdir(tmpdir);
+
+       return 0;
 }
+#endif
 
-static int cert_process_revoker(const char *certfile) {
-       fprintf(stderr, "not implemented\n");
-       return 1;
+/* process revoker certificate */
+static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
+       static LIST_HEAD(certchain);
+       struct cert_object *cobj;
+       struct blob_attr *containertb[CERT_CT_ATTR_MAX];
+       struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
+       struct stat st;
+       struct timeval tv;
+       time_t validfrom;
+       enum certtype_id certtype;
+       char *fingerprint;
+       char rfname[512];
+
+       int ret;
+
+       if (cert_load(certfile, &certchain)) {
+               DPRINTF("cannot parse cert\n");
+               return 1;
+       }
+
+       gettimeofday(&tv, NULL);
+
+       list_for_each_entry(cobj, &certchain, list) {
+               if (!cobj->cert[CERT_ATTR_PAYLOAD])
+                       return 2;
+
+               /* blob has payload, verify that using signature */
+               ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
+               if (ret)
+                       return ret;
+
+               blobmsg_parse(cert_cont_policy,
+                             ARRAY_SIZE(cert_cont_policy),
+                             containertb,
+                             blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
+                             blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
+               if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
+                       DPRINTF("no ucert in signed payload\n");
+                       return 2;
+               }
+
+               blobmsg_parse(cert_payload_policy,
+                             ARRAY_SIZE(cert_payload_policy),
+                             payloadtb,
+                             blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
+                             blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
+
+               if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
+                   !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
+                   !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
+                       DPRINTF("missing mandatory ucert attributes\n");
+                       return 2;
+               }
+
+               certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
+               validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
+               fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
+
+               if (certtype != CERTTYPE_REVOKE) {
+                       DPRINTF("wrong certificate type\n");
+                       return 2;
+               }
+
+               if (tv.tv_sec < validfrom) {
+                       return 3;
+               }
+
+               snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
+               /* check if entry in pubkeydir exists */
+               if (stat(rfname, &st) == 0) {
+                       if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
+                               DPRINTF("existing revoker deadlink for key %s\n", fingerprint);
+                               continue;
+                       };
+
+                       /* remove any other entry */
+                       if (unlink(rfname))
+                               return -1;
+               }
+
+               ret = symlink(".revoked.", rfname);
+               if (ret)
+                       return ret;
+
+               DPRINTF("created revoker deadlink for key %s\n", fingerprint);
+       };
+
+       return ret;
 }
 
+/* load and verify certfile (and message) */
 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
-       fprintf(stderr, "not implemented\n");
-       return 1;
+       static LIST_HEAD(certchain);
+
+       if (cert_load(certfile, &certchain)) {
+               DPRINTF("cannot parse cert\n");
+               return 1;
+       }
+
+       return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
 }
 
+/* output help */
 static int usage(const char *cmd)
 {
+#ifndef UCERT_STRIP_MESSAGES
        fprintf(stderr,
                "Usage: %s <command> <options>\n"
                "Commands:\n"
-               "  -A:                  append (needs -c and -p and/or -x)\n"
-               "  -D:                  dump\n"
+#ifdef UCERT_FULL
+               "  -A:                  append signature (needs -c and -x)\n"
+               "  -D:                  dump (needs -c)\n"
                "  -I:                  issue cert and revoker (needs -c and -p and -s)\n"
-               "  -R:                  process revoker certificate (needs -c)\n"
-               "  -V:                  verify (needs -c and -p|-P)\n"
+#endif /* UCERT_FULL */
+               "  -R:                  process revoker certificate (needs -c and -P)\n"
+               "  -V:                  verify (needs -c and -p|-P, may have -m)\n"
                "Options:\n"
                "  -c <file>:           certificate file\n"
                "  -m <file>:           message file (verify only)\n"
                "  -p <file>:           public key file\n"
                "  -P <path>:           public key directory (verify only)\n"
                "  -q:                  quiet (do not print verification result, use return code only)\n"
+#ifdef UCERT_FULL
                "  -s <file>:           secret key file (issue only)\n"
-               "  -x <file>:           signature file\n"
+               "  -x <file>:           signature file (append only)\n"
+#endif /* UCERT_FULL */
                "\n",
                cmd);
+#endif /* UCERT_STRIP_MESSAGES */
        return 1;
 }
 
+/* parse command line options and call functions */
 int main(int argc, char *argv[]) {
        int ch;
        const char *msgfile = NULL;
-       const char *sigfile = NULL;
        const char *pubkeyfile = NULL;
        const char *pubkeydir = NULL;
        const char *certfile = NULL;
+#ifdef UCERT_FULL
+       const char *sigfile = NULL;
        const char *seckeyfile = NULL;
+#endif
 
        quiet = false;
-       while ((ch = getopt(argc, argv, "ADIRVc:m:p:P:qs:x:")) != -1) {
+       while ((ch = getopt(argc, argv,
+               "RVc:m:p:P:q"
+#ifdef UCERT_FULL
+               "ADIs:x:"
+#endif
+              )) != -1) {
                switch (ch) {
+#ifdef UCERT_FULL
                case 'A':
+                       if (cmd != CMD_NONE)
+                               return usage(argv[0]);
                        cmd = CMD_APPEND;
                        break;
                case 'D':
+                       if (cmd != CMD_NONE)
+                               return usage(argv[0]);
                        cmd = CMD_DUMP;
                        break;
                case 'I':
+                       if (cmd != CMD_NONE)
+                               return usage(argv[0]);
                        cmd = CMD_ISSUE;
                        break;
+#endif
                case 'R':
+                       if (cmd != CMD_NONE)
+                               return usage(argv[0]);
                        cmd = CMD_REVOKE;
                        break;
                case 'V':
+                       if (cmd != CMD_NONE)
+                               return usage(argv[0]);
                        cmd = CMD_VERIFY;
                        break;
                case 'c':
+                       if (certfile || cmd == CMD_NONE)
+                               return usage(argv[0]);
                        certfile = optarg;
                        break;
                case 'm':
+                       if (msgfile || cmd != CMD_VERIFY)
+                               return usage(argv[0]);
                        msgfile = optarg;
                        break;
                case 'p':
+                       if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
+                               return usage(argv[0]);
                        pubkeyfile = optarg;
                        break;
                case 'P':
+                       if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
+                               return usage(argv[0]);
                        pubkeydir = optarg;
                        break;
-               case 's':
-                       seckeyfile = optarg;
-                       break;
                case 'q':
+                       if (quiet)
+                               return usage(argv[0]);
                        quiet = true;
                        break;
+#ifdef UCERT_FULL
+               case 's':
+                       if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
+                               return usage(argv[0]);
+                       seckeyfile = optarg;
+                       break;
                case 'x':
+                       if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
+                               return usage(argv[0]);
                        sigfile = optarg;
                        break;
+#endif
                default:
                        return usage(argv[0]);
                }
        }
 
        switch (cmd) {
+#ifdef UCERT_FULL
        case CMD_APPEND:
-               if (certfile && (pubkeyfile || sigfile))
-                       return cert_append(certfile, pubkeyfile, sigfile);
+               if (certfile && sigfile)
+                       return cert_append(certfile, sigfile);
                else
                        return usage(argv[0]);
        case CMD_DUMP:
@@ -160,9 +733,10 @@ int main(int argc, char *argv[]) {
                        return cert_issue(certfile, pubkeyfile, seckeyfile);
                else
                        return usage(argv[0]);
+#endif
        case CMD_REVOKE:
-               if (certfile)
-                       return cert_process_revoker(certfile);
+               if (certfile && pubkeydir)
+                       return cert_process_revoker(certfile, pubkeydir);
                else
                        return usage(argv[0]);
        case CMD_VERIFY:
@@ -170,7 +744,7 @@ int main(int argc, char *argv[]) {
                        return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
                else
                        return usage(argv[0]);
-       case CMD_NONE:
+       default:
                return usage(argv[0]);
        }