add comments and license headers

[oweals/ucert.git] / ucert.c

diff --git a/ucert.c b/ucert.c
index 13975d10e97dacc3b2645feb2f75bb29407472d9..12b42a875830f0e6857b2e8c5d953befd413562f 100644 (file)
--- a/ucert.c
+++ b/ucert.c
@@ -48,6 +48,13 @@ static enum {
 
 static bool quiet;
 
+/*
+ * ucert structure
+ * |               BLOB                    |
+ * |    SIGNATURE    |       PAYLOAD       |
+ * |                 |[ BLOBMSG CONTAINER ]|
+ * |                 |[[T,i,v,e,f,pubkey ]]|
+ */
 enum cert_attr {
        CERT_ATTR_SIGNATURE,
        CERT_ATTR_PAYLOAD,
@@ -93,11 +100,13 @@ static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
        [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;
@@ -111,6 +120,7 @@ static int write_file(const char *filename, void *buf, size_t len, bool append)
        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];
@@ -157,6 +167,7 @@ static int cert_load(const char *certfile, struct list_head *chain) {
        return (ret <= 0);
 }
 
+/* append signature to certfile */
 static int cert_append(const char *certfile, const char *sigfile) {
        FILE *fs;
        char filebuf[CERT_BUF_LEN];
@@ -181,6 +192,7 @@ static int cert_append(const char *certfile, const char *sigfile) {
        return ret;
 }
 
+/* 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;
@@ -219,6 +231,7 @@ static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
        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;
@@ -226,6 +239,7 @@ static int chain_verify(const char *msgfile, const char *pubkeyfile,
        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;
@@ -295,6 +309,19 @@ static int chain_verify(const char *msgfile, const char *pubkeyfile,
                                   blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
                                   blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
                                   false);
+
+                       if (usign_f_pubkey(chainedfp, chainedpubkey)) {
+                               if (!quiet)
+                                       fprintf(stderr, "cannot get fingerprint for chained key\n");
+                               ret = 2;
+                               goto clean_and_return;
+                       }
+                       if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
+                               if (!quiet)
+                                       fprintf(stderr, "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) {
@@ -324,6 +351,7 @@ clean_and_return:
        return ret | checkmsg;
 }
 
+/* dump single chain element to console */
 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
        int i;
 
@@ -344,6 +372,7 @@ static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
        }
 }
 
+/* dump certfile to console */
 static int cert_dump(const char *certfile) {
        struct cert_object *cobj;
        static LIST_HEAD(certchain);
@@ -363,6 +392,7 @@ static int cert_dump(const char *certfile) {
        return 0;
 }
 
+/* issue an auth certificate for pubkey */
 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
        struct blob_buf certbuf;
        struct blob_buf payloadbuf;
@@ -454,6 +484,7 @@ static int cert_issue(const char *certfile, const char *pubkeyfile, const char *
        return 0;
 }
 
+/* process revoker certificate */
 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
        static LIST_HEAD(certchain);
        struct cert_object *cobj;
@@ -500,9 +531,9 @@ static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
                if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
                    !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
                    !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
-                               fprintf(stderr, "missing mandatory ucert attributes\n");
-                               return 2;
-                       }
+                       fprintf(stderr, "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]);
@@ -521,10 +552,7 @@ static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
                snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
                /* check if entry in pubkeydir exists */
                if (stat(rfname, &st) == 0) {
-                       char tml[64] = {0};
-                       /* if it's an existing revoker deadlink we are happy */
-                       if (readlink(rfname, tml, sizeof(tml)) > 0 &&
-                           !strcmp(tml, ".revoked.")) {
+                       if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
                                if (!quiet)
                                        fprintf(stdout, "existing revoker deadlink for key %s\n", fingerprint);
                                continue;
@@ -546,6 +574,7 @@ static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
        return ret;
 }
 
+/* load and verify certfile (and message) */
 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
        static LIST_HEAD(certchain);
 
@@ -557,6 +586,7 @@ static int cert_verify(const char *certfile, const char *pubkeyfile, const char
        return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
 }
 
+/* output help */
 static int usage(const char *cmd)
 {
        fprintf(stderr,
@@ -580,6 +610,7 @@ static int usage(const char *cmd)
        return 1;
 }
 
+/* parse command line options and call functions */
 int main(int argc, char *argv[]) {
        int ch;
        const char *msgfile = NULL;