diff options
| -rw-r--r-- | sys/src/libsec/port/x509.c | 63 |
1 files changed, 38 insertions, 25 deletions
diff --git a/sys/src/libsec/port/x509.c b/sys/src/libsec/port/x509.c index 9d10145b4..560b02ad4 100644 --- a/sys/src/libsec/port/x509.c +++ b/sys/src/libsec/port/x509.c @@ -2145,7 +2145,7 @@ asn1toDSApriv(uchar *kd, int kn) * Our ASN.1 library doesn't return pointers into the original * data array, so we need to do a little hand decoding. */ -static void +static int digest_certinfo(Bytes *cert, DigestAlg *da, uchar *digest) { uchar *info, *p, *pend; @@ -2161,19 +2161,20 @@ digest_certinfo(Bytes *cert, DigestAlg *da, uchar *digest) length_decode(&p, pend, &length) != ASN_OK || p+length > pend || p+length < p) - return; + return -1; info = p; if(ber_decode(&p, pend, &elem) != ASN_OK) - return; + return -1; freevalfields(&elem.val); if(elem.tag.num != SEQUENCE) - return; + return -1; infolen = p - info; (*da->fun)(info, infolen, digest, nil); + return da->len; } static char* -verify_signature(Bytes* signature, RSApub *pk, uchar *edigest, Elem **psigalg) +verify_signature(Bytes* signature, RSApub *pk, uchar *edigest, int edigestlen, Elem **psigalg) { Elem e; Elist *el; @@ -2199,24 +2200,26 @@ verify_signature(Bytes* signature, RSApub *pk, uchar *edigest, Elem **psigalg) err = "expected 1"; goto end; } - buf++; - while(buf[0] == 0xff) - buf++; - if(buf[0] != 0) { + buf++, buflen--; + while(buflen > 0 && buf[0] == 0xff) + buf++, buflen--; + if(buflen < 1 || buf[0] != 0) { err = "expected 0"; goto end; } - buf++; - buflen -= buf-pkcs1buf; + buf++, buflen--; if(decode(buf, buflen, &e) != ASN_OK || !is_seq(&e, &el) || elistlen(el) != 2 || !is_octetstring(&el->tl->hd, &digest)) { err = "signature parse error"; goto end; } *psigalg = &el->hd; - if(memcmp(digest->data, edigest, digest->len) == 0) + if(digest->len != edigestlen) { + err = "bad digest length"; goto end; - err = "digests did not match"; + } + if(memcmp(digest->data, edigest, edigestlen) != 0) + err = "digests did not match"; end: if(pkcs1 != nil) @@ -2256,17 +2259,23 @@ X509verify(uchar *cert, int ncert, RSApub *pk) char *e; Bytes *b; CertX509 *c; - uchar digest[256]; + int digestlen; + uchar digest[MAXdlen]; Elem *sigalg; b = makebytes(cert, ncert); c = decode_cert(b); - if(c != nil) - digest_certinfo(b, digestalg[c->signature_alg], digest); - freebytes(b); - if(c == nil) + if(c == nil){ + freebytes(b); return "cannot decode cert"; - e = verify_signature(c->signature, pk, digest, &sigalg); + } + digestlen = digest_certinfo(b, digestalg[c->signature_alg], digest); + freebytes(b); + if(digestlen <= 0){ + freecert(c); + return "cannot decode certinfo"; + } + e = verify_signature(c->signature, pk, digest, digestlen, &sigalg); freecert(c); return e; } @@ -2671,7 +2680,7 @@ X509dump(uchar *cert, int ncert) Bytes *b; CertX509 *c; RSApub *pk; - DigestAlg *da; + int digestlen; uchar digest[MAXdlen]; Elem *sigalg; @@ -2680,12 +2689,16 @@ X509dump(uchar *cert, int ncert) c = decode_cert(b); if(c == nil){ freebytes(b); - print("cannot decode cert"); + print("cannot decode cert\n"); return; } - da = digestalg[c->signature_alg]; - digest_certinfo(b, da, digest); + digestlen = digest_certinfo(b, digestalg[c->signature_alg], digest); freebytes(b); + if(digestlen <= 0){ + freecert(c); + print("cannot decode certinfo\n"); + return; + } print("serial %d\n", c->serial); print("issuer %s\n", c->issuer); @@ -2694,8 +2707,8 @@ X509dump(uchar *cert, int ncert) pk = decode_rsapubkey(c->publickey); print("pubkey e=%B n(%d)=%B\n", pk->ek, mpsignif(pk->n), pk->n); - print("sigalg=%d digest=%.*H\n", c->signature_alg, da->len, digest); - e = verify_signature(c->signature, pk, digest, &sigalg); + print("sigalg=%d digest=%.*H\n", c->signature_alg, digestlen, digest); + e = verify_signature(c->signature, pk, digest, digestlen, &sigalg); if(e==nil){ e = "nil (meaning ok)"; print("sigalg=\n"); |