rpm/lib/signature.c

536 lines
13 KiB
C

/** \ingroup signature
* \file lib/signature.c
*/
#include "system.h"
#include <inttypes.h>
#include <netinet/in.h>
#include <rpm/rpmtypes.h>
#include <rpm/rpmstring.h>
#include <rpm/rpmfileutil.h>
#include <rpm/rpmlog.h>
#include <rpm/rpmkeyring.h>
#include "lib/rpmlead.h"
#include "lib/signature.h"
#include "lib/header_internal.h"
#include "debug.h"
/* Dumb wrapper around headerPut() for signature header */
static int sighdrPut(Header h, rpmTagVal tag, rpmTagType type,
rpm_data_t p, rpm_count_t c)
{
struct rpmtd_s sigtd;
rpmtdReset(&sigtd);
sigtd.tag = tag;
sigtd.type = type;
sigtd.data = p;
sigtd.count = c;
return headerPut(h, &sigtd, HEADERPUT_DEFAULT);
}
/**
* Print package size.
* @todo rpmio: use fdSize rather than fstat(2) to get file size.
* @param fd package file handle
* @param siglen signature header size
* @param pad signature padding
* @param datalen length of header+payload
* @return rpmRC return code
*/
static inline rpmRC printSize(FD_t fd, size_t siglen, size_t pad, rpm_loff_t datalen)
{
struct stat st;
int fdno = Fileno(fd);
if (fstat(fdno, &st) < 0)
return RPMRC_FAIL;
rpmlog(RPMLOG_DEBUG,
"Expected size: %12" PRIu64 \
" = lead(%d)+sigs(%zd)+pad(%zd)+data(%" PRIu64 ")\n",
RPMLEAD_SIZE+siglen+pad+datalen,
RPMLEAD_SIZE, siglen, pad, datalen);
rpmlog(RPMLOG_DEBUG,
" Actual size: %12" PRIu64 "\n", (rpm_loff_t) st.st_size);
return RPMRC_OK;
}
rpmRC rpmReadSignature(FD_t fd, Header * sighp, sigType sig_type, char ** msg)
{
char *buf = NULL;
int32_t block[4];
int32_t il;
int32_t dl;
int32_t * ei = NULL;
entryInfo pe;
unsigned int nb, uc;
int32_t ril = 0;
struct indexEntry_s entry;
struct entryInfo_s info;
unsigned char * dataStart;
unsigned char * dataEnd = NULL;
Header sigh = NULL;
rpmRC rc = RPMRC_FAIL; /* assume failure */
int xx;
int i;
if (sighp)
*sighp = NULL;
if (sig_type != RPMSIGTYPE_HEADERSIG)
goto exit;
memset(block, 0, sizeof(block));
if ((xx = Fread(block, 1, sizeof(block), fd)) != sizeof(block)) {
rasprintf(&buf, _("sigh size(%d): BAD, read returned %d\n"),
(int)sizeof(block), xx);
goto exit;
}
if (memcmp(block, rpm_header_magic, sizeof(rpm_header_magic))) {
rasprintf(&buf, _("sigh magic: BAD\n"));
goto exit;
}
il = ntohl(block[2]);
if (il < 0 || il > 32) {
rasprintf(&buf,
_("sigh tags: BAD, no. of tags(%d) out of range\n"), il);
goto exit;
}
dl = ntohl(block[3]);
if (dl < 0 || dl > 8192) {
rasprintf(&buf,
_("sigh data: BAD, no. of bytes(%d) out of range\n"), dl);
goto exit;
}
memset(&entry, 0, sizeof(entry));
memset(&info, 0, sizeof(info));
nb = (il * sizeof(struct entryInfo_s)) + dl;
uc = sizeof(il) + sizeof(dl) + nb;
ei = xmalloc(uc);
ei[0] = block[2];
ei[1] = block[3];
pe = (entryInfo) &ei[2];
dataStart = (unsigned char *) (pe + il);
if ((xx = Fread(pe, 1, nb, fd)) != nb) {
rasprintf(&buf,
_("sigh blob(%d): BAD, read returned %d\n"), (int)nb, xx);
goto exit;
}
/* Check (and convert) the 1st tag element. */
xx = headerVerifyInfo(1, dl, pe, &entry.info, 0);
if (xx != -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);
goto exit;
}
/* Is there an immutable header region tag? */
if (entry.info.tag == RPMTAG_HEADERSIGNATURES
&& entry.info.type == RPM_BIN_TYPE
&& entry.info.count == REGION_TAG_COUNT)
{
/* Is the trailer within the data area? */
if (entry.info.offset + REGION_TAG_COUNT > dl) {
rasprintf(&buf,
_("region offset: BAD, tag %d type %d offset %d count %d\n"),
entry.info.tag, entry.info.type,
entry.info.offset, entry.info.count);
goto exit;
}
/* Is there an immutable header region tag trailer? */
dataEnd = dataStart + entry.info.offset;
(void) memcpy(&info, dataEnd, REGION_TAG_COUNT);
/* XXX Really old packages have HEADER_IMAGE, not HEADER_SIGNATURES. */
if (info.tag == htonl(RPMTAG_HEADERIMAGE)) {
rpmTagVal stag = htonl(RPMTAG_HEADERSIGNATURES);
info.tag = stag;
memcpy(dataEnd, &stag, sizeof(stag));
}
dataEnd += REGION_TAG_COUNT;
xx = headerVerifyInfo(1, dl, &info, &entry.info, 1);
if (xx != -1 ||
!((entry.info.tag == RPMTAG_HEADERSIGNATURES || entry.info.tag == RPMTAG_HEADERIMAGE)
&& entry.info.type == RPM_BIN_TYPE
&& entry.info.count == REGION_TAG_COUNT))
{
rasprintf(&buf,
_("region trailer: BAD, tag %d type %d offset %d count %d\n"),
entry.info.tag, entry.info.type,
entry.info.offset, entry.info.count);
goto exit;
}
memset(&info, 0, sizeof(info));
/* Is the no. of tags in the region less than the total no. of tags? */
ril = entry.info.offset/sizeof(*pe);
if ((entry.info.offset % sizeof(*pe)) || ril > il) {
rasprintf(&buf, _("region size: BAD, ril(%d) > il(%d)\n"), ril, il);
goto exit;
}
}
/* Sanity check signature tags */
memset(&info, 0, sizeof(info));
for (i = 1; i < il; i++) {
xx = headerVerifyInfo(1, dl, pe+i, &entry.info, 0);
if (xx != -1) {
rasprintf(&buf,
_("sigh 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;
}
}
/* OK, blob looks sane, load the header. */
sigh = headerImport(ei, uc, 0);
if (sigh == NULL) {
rasprintf(&buf, _("sigh load: BAD\n"));
goto exit;
}
{ size_t sigSize = headerSizeof(sigh, HEADER_MAGIC_YES);
size_t pad = (8 - (sigSize % 8)) % 8; /* 8-byte pad */
ssize_t trc;
struct rpmtd_s sizetag;
rpm_loff_t archSize = 0;
/* Position at beginning of header. */
if (pad && (trc = Fread(block, 1, pad, fd)) != pad) {
rasprintf(&buf,
_("sigh pad(%zd): BAD, read %zd bytes\n"), pad, trc);
goto exit;
}
/* Print package component sizes. */
if (headerGet(sigh, RPMSIGTAG_LONGSIZE, &sizetag, HEADERGET_DEFAULT)) {
rpm_loff_t *tsize = rpmtdGetUint64(&sizetag);
archSize = (tsize) ? *tsize : 0;
} else if (headerGet(sigh, RPMSIGTAG_SIZE, &sizetag, HEADERGET_DEFAULT)) {
rpm_off_t *tsize = rpmtdGetUint32(&sizetag);
archSize = (tsize) ? *tsize : 0;
}
rpmtdFreeData(&sizetag);
rc = printSize(fd, sigSize, pad, archSize);
if (rc != RPMRC_OK) {
rasprintf(&buf,
_("sigh sigSize(%zd): BAD, fstat(2) failed\n"), sigSize);
goto exit;
}
}
ei = NULL; /* XXX will be freed with header */
exit:
if (sighp && sigh && rc == RPMRC_OK)
*sighp = headerLink(sigh);
headerFree(sigh);
free(ei);
if (msg != NULL) {
*msg = buf;
} else {
free(buf);
}
return rc;
}
int rpmWriteSignature(FD_t fd, Header sigh)
{
static uint8_t buf[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
int sigSize, pad;
int rc;
rc = headerWrite(fd, sigh, HEADER_MAGIC_YES);
if (rc)
return rc;
sigSize = headerSizeof(sigh, HEADER_MAGIC_YES);
pad = (8 - (sigSize % 8)) % 8;
if (pad) {
if (Fwrite(buf, sizeof(buf[0]), pad, fd) != pad)
rc = 1;
}
rpmlog(RPMLOG_DEBUG, "Signature: size(%d)+pad(%d)\n", sigSize, pad);
return rc;
}
Header rpmNewSignature(void)
{
Header sigh = headerNew();
return sigh;
}
Header rpmFreeSignature(Header sigh)
{
return headerFree(sigh);
}
static int makeHDRDigest(Header sigh, const char * file, rpmTagVal sigTag)
{
Header h = NULL;
FD_t fd = NULL;
char * SHA1 = NULL;
int ret = -1; /* assume failure. */
switch (sigTag) {
case RPMSIGTAG_SHA1:
fd = Fopen(file, "r.fdio");
if (fd == NULL || Ferror(fd))
goto exit;
h = headerRead(fd, HEADER_MAGIC_YES);
if (h == NULL)
goto exit;
if (headerIsEntry(h, RPMTAG_HEADERIMMUTABLE)) {
DIGEST_CTX ctx;
struct rpmtd_s utd;
if (!headerGet(h, RPMTAG_HEADERIMMUTABLE, &utd, HEADERGET_DEFAULT)
|| utd.data == NULL)
{
rpmlog(RPMLOG_ERR,
_("Immutable header region could not be read. "
"Corrupted package?\n"));
goto exit;
}
ctx = rpmDigestInit(PGPHASHALGO_SHA1, RPMDIGEST_NONE);
(void) rpmDigestUpdate(ctx, rpm_header_magic, sizeof(rpm_header_magic));
(void) rpmDigestUpdate(ctx, utd.data, utd.count);
(void) rpmDigestFinal(ctx, (void **)&SHA1, NULL, 1);
rpmtdFreeData(&utd);
} else {
rpmlog(RPMLOG_ERR, _("Cannot sign RPM v3 packages\n"));
goto exit;
}
if (SHA1 == NULL)
goto exit;
if (!sighdrPut(sigh, RPMSIGTAG_SHA1, RPM_STRING_TYPE, SHA1, 1))
goto exit;
ret = 0;
break;
default:
break;
}
exit:
free(SHA1);
headerFree(h);
if (fd != NULL) (void) Fclose(fd);
return ret;
}
int rpmGenDigest(Header sigh, const char * file, rpmTagVal sigTag)
{
struct stat st;
uint8_t * pkt = NULL;
size_t pktlen;
int ret = -1; /* assume failure. */
switch (sigTag) {
case RPMSIGTAG_SIZE: {
rpm_off_t size;
if (stat(file, &st) != 0)
break;
size = st.st_size;
if (!sighdrPut(sigh, sigTag, RPM_INT32_TYPE, &size, 1))
break;
ret = 0;
} break;
case RPMSIGTAG_LONGSIZE: {
rpm_loff_t size;
if (stat(file, &st) != 0)
break;
size = st.st_size;
if (!sighdrPut(sigh, sigTag, RPM_INT64_TYPE, &size, 1))
break;
ret = 0;
} break;
case RPMSIGTAG_MD5:
pktlen = 16;
pkt = xcalloc(pktlen, sizeof(*pkt));
if (rpmDoDigest(PGPHASHALGO_MD5, file, 0, pkt, NULL)
|| !sighdrPut(sigh, sigTag, RPM_BIN_TYPE, pkt, pktlen))
break;
ret = 0;
break;
case RPMSIGTAG_SHA1:
ret = makeHDRDigest(sigh, file, sigTag);
break;
default:
break;
}
free(pkt);
return ret;
}
static const char * rpmSigString(rpmRC res)
{
const char * str;
switch (res) {
case RPMRC_OK: str = "OK"; break;
case RPMRC_FAIL: str = "BAD"; break;
case RPMRC_NOKEY: str = "NOKEY"; break;
case RPMRC_NOTTRUSTED: str = "NOTRUSTED"; break;
default:
case RPMRC_NOTFOUND: str = "UNKNOWN"; break;
}
return str;
}
static rpmRC
verifyMD5Digest(rpmtd sigtd, DIGEST_CTX md5ctx, char **msg)
{
rpmRC res = RPMRC_FAIL; /* assume failure */
uint8_t * md5sum = NULL;
size_t md5len = 0;
char *md5;
const char *title = _("MD5 digest:");
*msg = NULL;
DIGEST_CTX ctx = rpmDigestDup(md5ctx);
if (ctx == NULL) {
rasprintf(msg, "%s %s\n", title, rpmSigString(res));
goto exit;
}
(void) rpmDigestFinal(ctx, (void **)&md5sum, &md5len, 0);
md5 = pgpHexStr(md5sum, md5len);
if (md5len != sigtd->count || memcmp(md5sum, sigtd->data, md5len)) {
char *hex = rpmtdFormat(sigtd, RPMTD_FORMAT_STRING, NULL);
rasprintf(msg, "%s %s Expected(%s) != (%s)\n", title,
rpmSigString(res), hex, md5);
free(hex);
} else {
res = RPMRC_OK;
rasprintf(msg, "%s %s (%s)\n", title, rpmSigString(res), md5);
}
free(md5);
exit:
md5sum = _free(md5sum);
return res;
}
/**
* Verify header immutable region SHA1 digest.
* @retval msg verbose success/failure text
* @param sha1ctx
* @return RPMRC_OK on success
*/
static rpmRC
verifySHA1Digest(rpmtd sigtd, DIGEST_CTX sha1ctx, char **msg)
{
rpmRC res = RPMRC_FAIL; /* assume failure */
char * SHA1 = NULL;
const char *title = _("Header SHA1 digest:");
const char *sig = sigtd->data;
*msg = NULL;
DIGEST_CTX ctx = rpmDigestDup(sha1ctx);
if (ctx == NULL) {
rasprintf(msg, "%s %s\n", title, rpmSigString(res));
goto exit;
}
(void) rpmDigestFinal(ctx, (void **)&SHA1, NULL, 1);
if (SHA1 == NULL || !rstreq(SHA1, sig)) {
rasprintf(msg, "%s %s Expected(%s) != (%s)\n", title,
rpmSigString(res), sig, SHA1 ? SHA1 : "(nil)");
} else {
res = RPMRC_OK;
rasprintf(msg, "%s %s (%s)\n", title, rpmSigString(res), SHA1);
}
exit:
SHA1 = _free(SHA1);
return res;
}
/**
* Verify DSA/RSA signature.
* @param keyring pubkey keyring
* @param sig OpenPGP signature parameters
* @param hashctx digest context
* @param isHdr header-only signature?
* @retval msg verbose success/failure text
* @return RPMRC_OK on success
*/
static rpmRC
verifySignature(rpmKeyring keyring, pgpDigParams sig, DIGEST_CTX hashctx,
int isHdr, char **msg)
{
rpmRC res = rpmKeyringVerifySig(keyring, sig, hashctx);
char *sigid = pgpIdentItem(sig);
rasprintf(msg, "%s%s: %s\n", isHdr ? _("Header ") : "", sigid,
rpmSigString(res));
free(sigid);
return res;
}
rpmRC
rpmVerifySignature(rpmKeyring keyring, rpmtd sigtd, pgpDigParams sig,
DIGEST_CTX ctx, char ** result)
{
rpmRC res = RPMRC_NOTFOUND;
char *msg = NULL;
int hdrsig = 0;
if (sigtd->data == NULL || sigtd->count <= 0 || ctx == NULL)
goto exit;
switch (sigtd->tag) {
case RPMSIGTAG_MD5:
res = verifyMD5Digest(sigtd, ctx, &msg);
break;
case RPMSIGTAG_SHA1:
res = verifySHA1Digest(sigtd, ctx, &msg);
break;
case RPMSIGTAG_RSA:
case RPMSIGTAG_DSA:
hdrsig = 1;
/* fallthrough */
case RPMSIGTAG_PGP5: /* XXX legacy */
case RPMSIGTAG_PGP:
case RPMSIGTAG_GPG:
if (sig != NULL)
res = verifySignature(keyring, sig, ctx, hdrsig, &msg);
break;
default:
break;
}
exit:
if (res == RPMRC_NOTFOUND) {
rasprintf(&msg,
_("Verify signature: BAD PARAMETERS (%d %p %d %p %p)\n"),
sigtd->tag, sigtd->data, sigtd->count, ctx, sig);
res = RPMRC_FAIL;
}
if (result) {
*result = msg;
} else {
free(msg);
}
return res;
}