Clean up pgpPrtPkts() and friends a bit

- Use decodePkt() for added initial sanity check + grabbing the "main" tag
  instead of duplicating the tag decoding here.
- Call decodePkt() from the main parse loop instead of pgpPrtPkt(),
  and return simple ok/error codes from pgpPrtPkt() and do the
  length calculation in the main loop.
- Besides making the code simpler and more obvious this fixes some
  fishy cases where we previously would've returned 0 for success
  despite there being an error.

diff --git a/rpmio/rpmpgp.c b/rpmio/rpmpgp.c
index 274f685..e64ea01 100644 (file)
--- a/rpmio/rpmpgp.c
+++ b/rpmio/rpmpgp.c
@@ -320,7 +320,7 @@ static int decodePkt(const uint8_t *p, size_t plen, struct pgpPkt *pkt)
     int rc = -1; /* assume failure */
 
     /* Valid PGP packet header must always have two or more bytes in it */
-    if (plen >= 2 && p[0] & 0x80) {
+    if (p && plen >= 2 && p[0] & 0x80) {
        size_t lenlen = 0;
        size_t hlen = 0;
 
@@ -790,28 +790,24 @@ int pgpExtractPubkeyFingerprint(const char * b64pkt, pgpKeyID_t keyid)
     return rc;
 }
 
-static int pgpPrtPkt(const uint8_t *pkt, size_t pleft, pgpDigParams _digp)
+static int pgpPrtPkt(struct pgpPkt *p, pgpDigParams _digp)
 {
-    struct pgpPkt p;
     int rc = 0;
 
-    if (decodePkt(pkt, pleft, &p))
-       return -1;
-
-    switch (p.tag) {
+    switch (p->tag) {
     case PGPTAG_SIGNATURE:
-       rc = pgpPrtSig(p.tag, p.body, p.blen, _digp);
+       rc = pgpPrtSig(p->tag, p->body, p->blen, _digp);
        break;
     case PGPTAG_PUBLIC_KEY:
        /* Get the public key fingerprint. */
-       if (!getFingerprint(p.body, p.blen, _digp->signid))
+       if (!getFingerprint(p->body, p->blen, _digp->signid))
            _digp->saved |= PGPDIG_SAVED_ID;
        else
            memset(_digp->signid, 0, sizeof(_digp->signid));
-       rc = pgpPrtKey(p.tag, p.body, p.blen, _digp);
+       rc = pgpPrtKey(p->tag, p->body, p->blen, _digp);
        break;
     case PGPTAG_USER_ID:
-       rc = pgpPrtUserID(p.tag, p.body, p.blen, _digp);
+       rc = pgpPrtUserID(p->tag, p->body, p->blen, _digp);
        break;
     case PGPTAG_COMMENT:
     case PGPTAG_COMMENT_OLD:
@@ -833,13 +829,13 @@ static int pgpPrtPkt(const uint8_t *pkt, size_t pleft, pgpDigParams _digp)
     case PGPTAG_PRIVATE_62:
     case PGPTAG_CONTROL:
     default:
-       pgpPrtVal("", pgpTagTbl, p.tag);
-       pgpPrtHex("", p.body, p.blen);
+       pgpPrtVal("", pgpTagTbl, p->tag);
+       pgpPrtHex("", p->body, p->blen);
        pgpPrtNL();
        break;
     }
 
-    return (rc ? -1 : (p.body - p.head) + p.blen);
+    return rc;
 }
 
 pgpDig pgpNewDig(void)
@@ -884,39 +880,34 @@ pgpDig pgpFreeDig(pgpDig dig)
 
 int pgpPrtPkts(const uint8_t * pkts, size_t pktlen, pgpDig dig, int printing)
 {
-    unsigned int val = (pkts != NULL) ? *pkts : 0;
-    const uint8_t *p;
-    size_t pleft;
-    int len;
+    const uint8_t *p = pkts;
+    const uint8_t *pend = pkts + pktlen;
     struct pgpDigParams_s tmp;
     pgpDigParams _digp = NULL;
-    unsigned int tag;
+    struct pgpPkt pkt;
 
-    if (!(val & 0x80))
+    if (decodePkt(pkts, pktlen, &pkt))
        return -1;
 
     _print = printing;
-    tag = (val & 0x40) ? (val & 0x3f) : ((val >> 2) & 0xf);
     if (dig != NULL) {
-       _digp = (tag == PGPTAG_SIGNATURE) ? &dig->signature : &dig->pubkey;
+       _digp = (pkt.tag == PGPTAG_SIGNATURE) ? &dig->signature : &dig->pubkey;
     } else {
        _digp = &tmp;
        memset(_digp, 0, sizeof(*_digp));
     }
-    _digp->tag = tag;
+    _digp->tag = pkt.tag;
 
-    for (p = pkts, pleft = pktlen; p < (pkts + pktlen); p += len, pleft -= len) {
-       len = pgpPrtPkt(p, pleft, _digp);
-        if (len <= 0)
-           return len;
-       if (len > pleft)        /* XXX shouldn't happen */
+    while (p < pend) {
+       if (decodePkt(p, (pend - p), &pkt) || pgpPrtPkt(&pkt, _digp))
            break;
+       p += (pkt.body - pkt.head) + pkt.blen;
     }
 
     if (_digp == &tmp)
        pgpCleanDigParams(_digp);
 
-    return 0;
+    return (p == pend) ? 0 : -1;
 }
 
 char *pgpIdentItem(pgpDigParams digp)