diff options
| -rw-r--r-- | dirmngr/ocsp.c | 2 | ||||
| -rw-r--r-- | sm/certcheck.c | 148 | ||||
| -rw-r--r-- | sm/verify.c | 4 |
3 files changed, 113 insertions, 41 deletions
diff --git a/dirmngr/ocsp.c b/dirmngr/ocsp.c index 0b846651c..6ed180955 100644 --- a/dirmngr/ocsp.c +++ b/dirmngr/ocsp.c @@ -305,7 +305,7 @@ do_ocsp_request (ctrl_t ctrl, ksba_ocsp_t ocsp, if (opt.verbose) log_info (_("OCSP responder at '%s' status: %s\n"), url, t); - /* Get the signature value now because we can all this function + /* Get the signature value now because we can call this function * only once. */ *r_sigval = ksba_ocsp_get_sig_val (ocsp, r_produced_at); diff --git a/sm/certcheck.c b/sm/certcheck.c index effab9ab9..68185332e 100644 --- a/sm/certcheck.c +++ b/sm/certcheck.c @@ -270,6 +270,41 @@ uint_from_buffer (const void *buffer, size_t buflen) } +/* Extract the hash algorithm and the salt length from the sigval. */ +static gpg_error_t +extract_pss_params (gcry_sexp_t s_sig, int *r_algo, unsigned int *r_saltlen) +{ + gpg_error_t err; + gcry_buffer_t ioarray[2] = { {0}, {0} }; + + err = gcry_sexp_extract_param (s_sig, "sig-val", + "&'hash-algo''salt-length'", + ioarray+0, ioarray+1, NULL); + if (err) + { + log_error ("extracting params from PSS failed: %s\n", gpg_strerror (err)); + return err; + } + + *r_algo = hash_algo_from_buffer (ioarray[0].data, ioarray[0].len); + *r_saltlen = uint_from_buffer (ioarray[1].data, ioarray[1].len); + xfree (ioarray[0].data); + xfree (ioarray[1].data); + if (*r_saltlen < 20) + { + log_error ("length of PSS salt too short\n"); + gcry_sexp_release (s_sig); + return gpg_error (GPG_ERR_DIGEST_ALGO); + } + if (!*r_algo) + { + return gpg_error (GPG_ERR_DIGEST_ALGO); + } + /* log_debug ("PSS hash=%d saltlen=%u\n", *r_algo, *r_saltlen); */ + return 0; +} + + /* Check the signature on CERT using the ISSUER-CERT. This function does only test the cryptographic signature and nothing else. It is assumed that the ISSUER_CERT is valid. */ @@ -320,35 +355,12 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) if (use_pss) { - /* Extract the hash algorithm and the salt length from the sigval. */ - gcry_buffer_t ioarray[2] = { {0}, {0} }; - - rc = gcry_sexp_extract_param (s_sig, "sig-val", - "&'hash-algo''salt-length'", - ioarray+0, ioarray+1, NULL); + rc = extract_pss_params (s_sig, &algo, &saltlen); if (rc) { gcry_sexp_release (s_sig); - log_error ("extracting params from PSS failed: %s\n", - gpg_strerror (rc)); return rc; } - algo = hash_algo_from_buffer (ioarray[0].data, ioarray[0].len); - saltlen = uint_from_buffer (ioarray[1].data, ioarray[1].len); - xfree (ioarray[0].data); - xfree (ioarray[1].data); - if (saltlen < 20) - { - log_error ("length of PSS salt too short\n"); - gcry_sexp_release (s_sig); - return gpg_error (GPG_ERR_DIGEST_ALGO); - } - if (!algo) - { - gcry_sexp_release (s_sig); - return gpg_error (GPG_ERR_DIGEST_ALGO); - } - /* log_debug ("PSS hash=%d saltlen=%u\n", algo, saltlen); */ } @@ -409,7 +421,7 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) } else { - /* RSA or DAS: Prepare the hash for verification. */ + /* RSA or DSA: Prepare the hash for verification. */ gcry_mpi_t frame; rc = do_encode_md (md, algo, pk_algo_from_sexp (s_pkey), @@ -447,10 +459,14 @@ gpgsm_check_cms_signature (ksba_cert_t cert, ksba_const_sexp_t sigval, { int rc; ksba_sexp_t p; - gcry_mpi_t frame; - gcry_sexp_t s_sig, s_hash, s_pkey; + gcry_sexp_t s_sig, s_hash, s_pkey, l1; size_t n; + const char *s; + int i; int pkalgo; + int use_pss; + unsigned int saltlen = 0; + if (r_pkalgo) *r_pkalgo = 0; @@ -468,6 +484,42 @@ gpgsm_check_cms_signature (ksba_cert_t cert, ksba_const_sexp_t sigval, return rc; } + /* Check whether rsaPSS is needed. This is indicated in the SIG-VAL + * using a flag. Only if we found that flag, we extract the PSS + * parameters for SIG-VAL. */ + use_pss = 0; + l1 = gcry_sexp_find_token (s_sig, "flags", 0); + if (l1) + { + /* Note that the flag parser assumes that the list of flags + * contains only strings and in particular not sublist. This is + * always the case or current libksba. */ + for (i=1; (s = gcry_sexp_nth_data (l1, i, &n)); i++) + if (n == 3 && !memcmp (s, "pss", 3)) + { + use_pss = 1; + break; + } + gcry_sexp_release (l1); + if (use_pss) + { + int algo; + + rc = extract_pss_params (s_sig, &algo, &saltlen); + if (rc) + { + gcry_sexp_release (s_sig); + return rc; + } + if (algo != mdalgo) + { + log_error ("PSS hash algo mismatch (%d/%d)\n", mdalgo, algo); + gcry_sexp_release (s_sig); + return gpg_error (GPG_ERR_DIGEST_ALGO); + } + } + } + p = ksba_cert_get_public_key (cert); n = gcry_sexp_canon_len (p, 0, NULL, NULL); if (!n) @@ -492,22 +544,42 @@ gpgsm_check_cms_signature (ksba_cert_t cert, ksba_const_sexp_t sigval, pkalgo = pk_algo_from_sexp (s_pkey); if (r_pkalgo) *r_pkalgo = pkalgo; - rc = do_encode_md (md, mdalgo, pkalgo, - gcry_pk_get_nbits (s_pkey), s_pkey, &frame); - if (rc) + + if (use_pss) { - gcry_sexp_release (s_sig); - gcry_sexp_release (s_pkey); - return rc; + rc = gcry_sexp_build (&s_hash, NULL, + "(data (flags pss)" + "(hash %s %b)" + "(salt-length %u))", + hash_algo_to_string (mdalgo), + (int)gcry_md_get_algo_dlen (mdalgo), + gcry_md_read (md, mdalgo), + saltlen); + if (rc) + BUG (); + } + else + { + /* RSA or DSA: Prepare the hash for verification. */ + gcry_mpi_t frame; + + rc = do_encode_md (md, mdalgo, pkalgo, + gcry_pk_get_nbits (s_pkey), s_pkey, &frame); + if (rc) + { + gcry_sexp_release (s_sig); + gcry_sexp_release (s_pkey); + return rc; + } + /* put hash into the S-Exp s_hash */ + if ( gcry_sexp_build (&s_hash, NULL, "%m", frame) ) + BUG (); + gcry_mpi_release (frame); } - /* put hash into the S-Exp s_hash */ - if ( gcry_sexp_build (&s_hash, NULL, "%m", frame) ) - BUG (); - gcry_mpi_release (frame); rc = gcry_pk_verify (s_sig, s_hash, s_pkey); if (DBG_X509) - log_debug ("gcry_pk_verify: %s\n", gpg_strerror (rc)); + log_debug ("gcry_pk_verify: %s\n", gpg_strerror (rc)); gcry_sexp_release (s_sig); gcry_sexp_release (s_hash); gcry_sexp_release (s_pkey); diff --git a/sm/verify.c b/sm/verify.c index b7b9fa8be..6d2f11055 100644 --- a/sm/verify.c +++ b/sm/verify.c @@ -412,8 +412,8 @@ gpgsm_verify (ctrl_t ctrl, int in_fd, int data_fd, estream_t out_fp) { log_debug ("signer %d - signature available (sigval hash=%d)", signer, sigval_hash_algo); -/* log_printhex ("sigval ", sigval, */ -/* gcry_sexp_canon_len (sigval, 0, NULL, NULL)); */ + /*log_printhex(sigval, gcry_sexp_canon_len (sigval, 0, NULL, NULL),*/ + /* "sigval "); */ } if (!sigval_hash_algo) sigval_hash_algo = algo; /* Fallback used e.g. with old libksba. */ |