Split signature/digest verification out of headerVerify()

- headerVerify() is big enough without having all the signature
  goo inline, just lift the whole signature/digest business into
  separate function. Supposedly no functional changes...

diff --git a/lib/package.c b/lib/package.c
index ceebe5d..fc1e20e 100644 (file)
--- a/lib/package.c
+++ b/lib/package.c
@@ -195,10 +195,136 @@ static rpmRC parsePGP(rpmtd sigtd, const char *type, pgpDig dig)
     return rc;
 }
 
+/*
+ * Argument monster to verify header-only signature/digest if there is
+ * one, otherwisereturn RPMRC_NOTFOUND to signal for plain sanity check.
+ */
+static rpmRC headerSigVerify(rpmKeyring keyring, rpmVSFlags vsflags,
+                            int il, int dl, int ril, int rdl,
+                            entryInfo pe, unsigned char * dataStart,
+                            char **buf)
+{
+    size_t siglen = 0;
+    rpmRC rc = RPMRC_FAIL;
+    pgpDig dig = NULL;
+    struct rpmtd_s sigtd;
+    struct entryInfo_s info, einfo;
+    int hashalgo = 0;
+
+    rpmtdReset(&sigtd);
+    memset(&info, 0, sizeof(info));
+    memset(&einfo, 0, sizeof(einfo));
+
+    /* Find a header-only digest/signature tag. */
+    for (int i = ril; i < il; i++) {
+       if (headerVerifyInfo(1, dl, pe+i, &einfo, 0) != -1) {
+           rasprintf(buf,
+               _("tag[%d]: BAD, tag %d type %d offset %d count %d\n"),
+               i, einfo.tag, einfo.type,
+               einfo.offset, einfo.count);
+           goto exit;
+       }
+
+       switch (einfo.tag) {
+       case RPMTAG_SHA1HEADER: {
+           size_t blen = 0;
+           unsigned const char * b;
+           if (vsflags & RPMVSF_NOSHA1HEADER)
+               break;
+           for (b = dataStart + einfo.offset; *b != '\0'; b++) {
+               if (strchr("0123456789abcdefABCDEF", *b) == NULL)
+                   break;
+               blen++;
+           }
+           if (einfo.type != RPM_STRING_TYPE || *b != '\0' || blen != 40)
+           {
+               rasprintf(buf, _("hdr SHA1: BAD, not hex\n"));
+               goto exit;
+           }
+           if (info.tag == 0) {
+               info = einfo;   /* structure assignment */
+               siglen = blen + 1;
+           }
+           } break;
+       case RPMTAG_RSAHEADER:
+           if (vsflags & RPMVSF_NORSAHEADER)
+               break;
+           if (einfo.type != RPM_BIN_TYPE) {
+               rasprintf(buf, _("hdr RSA: BAD, not binary\n"));
+               goto exit;
+           }
+           info = einfo;       /* structure assignment */
+           siglen = info.count;
+           break;
+       case RPMTAG_DSAHEADER:
+           if (vsflags & RPMVSF_NODSAHEADER)
+               break;
+           if (einfo.type != RPM_BIN_TYPE) {
+               rasprintf(buf, _("hdr DSA: BAD, not binary\n"));
+               goto exit;
+           }
+           info = einfo;       /* structure assignment */
+           siglen = info.count;
+           break;
+       default:
+           break;
+       }
+    }
+
+    /* No header-only digest/signature found, get outta here */
+    if (info.tag == 0) {
+       rc = RPMRC_NOTFOUND;
+       goto exit;
+    }
+
+    /* This is dumb, pgpDig is only relevant for signatures, not digests */
+    dig = pgpNewDig();
+
+    sigtd.tag = info.tag;
+    sigtd.type = info.type;
+    sigtd.count = info.count;
+    sigtd.data = memcpy(xmalloc(siglen), dataStart + info.offset, siglen);
+    sigtd.flags = RPMTD_ALLOCED;
+
+    switch (info.tag) {
+    case RPMTAG_RSAHEADER:
+    case RPMTAG_DSAHEADER:
+       if ((rc = parsePGP(&sigtd, "header", dig)) != RPMRC_OK) {
+           goto exit;
+       }
+       hashalgo = dig->signature.hash_algo;
+       break;
+    case RPMTAG_SHA1HEADER:
+       hashalgo = PGPHASHALGO_SHA1;
+       break;
+    default:
+       break;
+    }
+
+    if (hashalgo) {
+       DIGEST_CTX ctx = rpmDigestInit(hashalgo, RPMDIGEST_NONE);
+       int32_t ildl[2] = { htonl(ril), htonl(rdl) };
+
+       rpmDigestUpdate(ctx, rpm_header_magic, sizeof(rpm_header_magic));
+       rpmDigestUpdate(ctx, ildl, sizeof(ildl));
+       rpmDigestUpdate(ctx, pe, (ril * sizeof(*pe)));
+       rpmDigestUpdate(ctx, dataStart, rdl);
+
+       rc = rpmVerifySignature(keyring, &sigtd, dig, ctx, buf);
+
+       rpmDigestFinal(ctx, NULL, NULL, 0);
+    }
+
+exit:
+    rpmtdFreeData(&sigtd);
+    pgpFreeDig(dig);
+
+    return rc;
+}
+
 static rpmRC headerVerify(rpmKeyring keyring, rpmVSFlags vsflags,
                          const void * uh, size_t uc, char ** msg)
 {
-    pgpDig dig = NULL;
     char *buf = NULL;
     int32_t * ei = (int32_t *) uh;
     int32_t il = ntohl(ei[0]);
@@ -208,18 +334,10 @@ static rpmRC headerVerify(rpmKeyring keyring, rpmVSFlags vsflags,
     unsigned char * dataStart = (unsigned char *) (pe + il);
     struct indexEntry_s entry;
     struct entryInfo_s info;
-    unsigned const char * b;
-    size_t siglen = 0;
-    size_t blen;
     int32_t ril = 0;
     unsigned char * regionEnd = NULL;
     rpmRC rc = RPMRC_FAIL;     /* assume failure */
-    int xx;
-    int i;
-    struct rpmtd_s sigtd;
-    DIGEST_CTX ctx = NULL;
 
-    rpmtdReset(&sigtd);
     /* Is the blob the right size? */
     if (uc > 0 && pvlen != uc) {
        rasprintf(&buf, _("blob size(%d): BAD, 8 + 16 * il(%d) + dl(%d)\n"),
@@ -231,8 +349,7 @@ static rpmRC headerVerify(rpmKeyring keyring, rpmVSFlags vsflags,
     memset(&info, 0, sizeof(info));
 
     /* Check (and convert) the 1st tag element. */
-    xx = headerVerifyInfo(1, dl, pe, &entry.info, 0);
-    if (xx != -1) {
+    if (headerVerifyInfo(1, dl, pe, &entry.info, 0) != -1) {
        rasprintf(&buf, _("tag[%d]: BAD, tag %d type %d offset %d count %d\n"),
                0, entry.info.tag, entry.info.type,
                entry.info.offset, entry.info.count);
@@ -262,8 +379,7 @@ static rpmRC headerVerify(rpmKeyring keyring, rpmVSFlags vsflags,
     (void) memcpy(&info, regionEnd, REGION_TAG_COUNT);
     regionEnd += REGION_TAG_COUNT;
 
-    xx = headerVerifyInfo(1, dl, &info, &entry.info, 1);
-    if (xx != -1 ||
+    if (headerVerifyInfo(1, dl, &info, &entry.info, 1) != -1 ||
        !(entry.info.tag == RPMTAG_HEADERIMMUTABLE
        && entry.info.type == RPM_BIN_TYPE
        && entry.info.count == REGION_TAG_COUNT))
@@ -283,108 +399,15 @@ static rpmRC headerVerify(rpmKeyring keyring, rpmVSFlags vsflags,
        goto exit;
     }
 
-    /* Find a header-only digest/signature tag. */
-    for (i = ril; i < il; i++) {
-       xx = headerVerifyInfo(1, dl, pe+i, &entry.info, 0);
-       if (xx != -1) {
-           rasprintf(&buf,
-               _("tag[%d]: BAD, tag %d type %d offset %d count %d\n"),
-               i, entry.info.tag, entry.info.type,
-               entry.info.offset, entry.info.count);
-           goto exit;
-       }
-
-       switch (entry.info.tag) {
-       case RPMTAG_SHA1HEADER:
-           if (vsflags & RPMVSF_NOSHA1HEADER)
-               break;
-           blen = 0;
-           for (b = dataStart + entry.info.offset; *b != '\0'; b++) {
-               if (strchr("0123456789abcdefABCDEF", *b) == NULL)
-                   break;
-               blen++;
-           }
-           if (entry.info.type != RPM_STRING_TYPE || *b != '\0' || blen != 40)
-           {
-               rasprintf(&buf, _("hdr SHA1: BAD, not hex\n"));
-               goto exit;
-           }
-           if (info.tag == 0) {
-               info = entry.info;      /* structure assignment */
-               siglen = blen + 1;
-           }
-           break;
-       case RPMTAG_RSAHEADER:
-           if (vsflags & RPMVSF_NORSAHEADER)
-               break;
-           if (entry.info.type != RPM_BIN_TYPE) {
-               rasprintf(&buf, _("hdr RSA: BAD, not binary\n"));
-               goto exit;
-           }
-           info = entry.info;  /* structure assignment */
-           siglen = info.count;
-           break;
-       case RPMTAG_DSAHEADER:
-           if (vsflags & RPMVSF_NODSAHEADER)
-               break;
-           if (entry.info.type != RPM_BIN_TYPE) {
-               rasprintf(&buf, _("hdr DSA: BAD, not binary\n"));
-               goto exit;
-           }
-           info = entry.info;  /* structure assignment */
-           siglen = info.count;
-           break;
-       default:
-           break;
-       }
-    }
-
-    /* No signature, skip to outro. */
-    if (info.tag == 0) {
-       rc = RPMRC_NOTFOUND;
-       goto exit;
-    }
-
-    /* Verify header-only digest/signature. */
-    dig = pgpNewDig();
-
-    sigtd.tag = info.tag;
-    sigtd.type = info.type;
-    sigtd.count = info.count;
-    sigtd.data = memcpy(xmalloc(siglen), dataStart + info.offset, siglen);
-    sigtd.flags = RPMTD_ALLOCED;
-
-    switch (info.tag) {
-    case RPMTAG_RSAHEADER:
-    case RPMTAG_DSAHEADER:
-       if ((rc = parsePGP(&sigtd, "header", dig)) != RPMRC_OK) {
-           goto exit;
-       }
-       /* fallthrough */
-    case RPMTAG_SHA1HEADER: {
-       int hashalgo = (info.tag == RPMTAG_SHA1HEADER) ?
-                       PGPHASHALGO_SHA1 : dig->signature.hash_algo;
-       int32_t ildl[2];
-       ildl[0] = htonl(ril);
-       ildl[1] = htonl(regionEnd - dataStart);
-
-       ctx = rpmDigestInit(hashalgo, RPMDIGEST_NONE);
-
-       rpmDigestUpdate(ctx, rpm_header_magic, sizeof(rpm_header_magic));
-       rpmDigestUpdate(ctx, ildl, sizeof(ildl));
-       rpmDigestUpdate(ctx, pe, (ril * sizeof(*pe)));
-       rpmDigestUpdate(ctx, dataStart, (regionEnd - dataStart));
-       } break;
-    default:
-       break;
-    }
-
-    rc = rpmVerifySignature(keyring, &sigtd, dig, ctx, &buf);
+    /* Verify header-only digest/signature if there is one we can use. */
+    rc = headerSigVerify(keyring, vsflags,
+                        il, dl, ril, (regionEnd - dataStart),
+                        pe, dataStart, &buf);
 
 exit:
     /* If no header-only digest/signature, then do simple sanity check. */
     if (rc == RPMRC_NOTFOUND) {
-       xx = headerVerifyInfo(ril-1, dl, pe+1, &entry.info, 0);
+       int xx = headerVerifyInfo(ril-1, dl, pe+1, &entry.info, 0);
        if (xx != -1) {
            rasprintf(&buf,
                _("tag[%d]: BAD, tag %d type %d offset %d count %d\n"),
@@ -402,9 +425,6 @@ exit:
     else
        free(buf);
 
-    rpmtdFreeData(&sigtd);
-    pgpFreeDig(dig);
-    rpmDigestFinal(ctx, NULL, NULL, 0);
     return rc;
 }