diff options
Diffstat (limited to 'sm')
| -rw-r--r-- | sm/certcheck.c | 137 | ||||
| -rw-r--r-- | sm/certdump.c | 22 | ||||
| -rw-r--r-- | sm/gpgsm.h | 1 |
3 files changed, 143 insertions, 17 deletions
diff --git a/sm/certcheck.c b/sm/certcheck.c index ad70f2781..3dcac2ffa 100644 --- a/sm/certcheck.c +++ b/sm/certcheck.c @@ -35,6 +35,7 @@ #include "keydb.h" #include "../common/i18n.h" +#include "../common/membuf.h" /* Return the number of bits of the Q parameter from the DSA key @@ -348,20 +349,27 @@ int gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) { const char *algoid; - gcry_md_hd_t md; + gcry_md_hd_t md = NULL; + void *certder = NULL; + size_t certderlen; int rc, algo; ksba_sexp_t p; size_t n; gcry_sexp_t s_sig, s_data, s_pkey; int use_pss = 0; + int use_eddsa = 0; unsigned int saltlen; algo = gcry_md_map_name ( (algoid=ksba_cert_get_digest_algo (cert))); if (!algo && algoid && !strcmp (algoid, "1.2.840.113549.1.1.10")) use_pss = 1; + else if (algoid && !strcmp (algoid, "1.3.101.112")) + use_eddsa = 1; + else if (algoid && !strcmp (algoid, "1.3.101.113")) + use_eddsa = 2; else if (!algo) { - log_error ("unknown digest algorithm '%s' used certificate\n", + log_error ("unknown digest algorithm '%s' used in certificate\n", algoid? algoid:"?"); if (algoid && ( !strcmp (algoid, "1.2.840.113549.1.1.2") @@ -400,24 +408,50 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) } - /* Hash the to-be-signed parts of the certificate. */ - rc = gcry_md_open (&md, algo, 0); - if (rc) + /* Hash the to-be-signed parts of the certificate or but them into a + * buffer for the EdDSA algorithms. */ + if (use_eddsa) { - log_error ("md_open failed: %s\n", gpg_strerror (rc)); - return rc; - } - if (DBG_HASHING) - gcry_md_debug (md, "hash.cert"); + membuf_t mb; - rc = ksba_cert_hash (cert, 1, HASH_FNC, md); - if (rc) + init_membuf (&mb, 2048); + rc = ksba_cert_hash (cert, 1, + (void (*)(void *, const void*,size_t))put_membuf, + &mb); + if (rc) + { + log_error ("ksba_cert_hash failed: %s\n", gpg_strerror (rc)); + xfree (get_membuf (&mb, NULL)); + return rc; + } + certder = get_membuf (&mb, &certderlen); + if (!certder) + { + rc = gpg_error_from_syserror (); + log_error ("getting tbsCertificate failed: %s\n", gpg_strerror (rc)); + return rc; + } + } + else { - log_error ("ksba_cert_hash failed: %s\n", gpg_strerror (rc)); - gcry_md_close (md); - return rc; + rc = gcry_md_open (&md, algo, 0); + if (rc) + { + log_error ("md_open failed: %s\n", gpg_strerror (rc)); + return rc; + } + if (DBG_HASHING) + gcry_md_debug (md, "hash.cert"); + + rc = ksba_cert_hash (cert, 1, HASH_FNC, md); + if (rc) + { + log_error ("ksba_cert_hash failed: %s\n", gpg_strerror (rc)); + gcry_md_close (md); + return rc; + } + gcry_md_final (md); } - gcry_md_final (md); /* Get the public key from the certificate. */ p = ksba_cert_get_public_key (issuer_cert); @@ -428,6 +462,7 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) gcry_md_close (md); ksba_free (p); gcry_sexp_release (s_sig); + xfree (certder); return gpg_error (GPG_ERR_BUG); } rc = gcry_sexp_sscan ( &s_pkey, NULL, (char*)p, n); @@ -437,6 +472,7 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) log_error ("gcry_sexp_scan failed: %s\n", gpg_strerror (rc)); gcry_md_close (md); gcry_sexp_release (s_sig); + xfree (certder); return rc; } if (DBG_CRYPTO) @@ -455,6 +491,21 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) if (rc) BUG (); } + else if (use_eddsa) + { + rc = gcry_sexp_build (&s_data, NULL, + "(data(flags eddsa)(hash-algo %s)(value %b))", + use_eddsa == 1? "sha512":"shake256", + (int)certderlen, certder); + xfree (certder); + certder = NULL; + if (rc) + { + log_error ("building data for eddsa failed: %s\n", gpg_strerror (rc)); + gcry_sexp_release (s_sig); + return rc; + } + } else { /* RSA or DSA: Prepare the hash for verification. */ @@ -479,7 +530,59 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) /* Verify. */ rc = gcry_pk_verify (s_sig, s_data, 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)); + if (use_eddsa && (gpg_err_code (rc) == GPG_ERR_INTERNAL + || gpg_err_code (rc) == GPG_ERR_INV_CURVE)) + { + /* Let's assume that this is a certificate for an ECDH key + * signed using EdDSA. This won't work. We should have located + * the public key using subjectKeyIdentifier (SKI) to not run + * into this problem. However, we don't do this for self-signed + * certificates and we don't have a way to search for arbitrary + * keys based on the SKI. Note: The sample certificate from + * RFC-8410 uses a SHA-1 hash of the public key for the SKI; so + * we are not able to verify it. + */ + ksba_sexp_t ski; + const unsigned char *skider; + size_t skiderlen; + + if (DBG_X509) + log_debug ("retrying using the ski\n"); + if (!ksba_cert_get_subj_key_id (issuer_cert, NULL, &ski)) + { + skider = gpgsm_get_serial (ski, &skiderlen); + if (!skider) + ; + else if (skiderlen == (use_eddsa==1? 32:57)) + { + /* Here we assume that the SKI is actually the public key. */ + gcry_sexp_release (s_pkey); + rc = gcry_sexp_build (&s_pkey, NULL, + "(public-key(ecc(curve%s)(q%b)))", + use_eddsa==1? "1.3.101.112":"1.3.101.113", + (int)skiderlen, skider); + if (rc) + log_error ("building pubkey from SKI failed: %s\n", + gpg_strerror (rc)); + else + rc = gcry_pk_verify (s_sig, s_data, s_pkey); + if (DBG_X509) + log_debug ("gcry_pk_verify: %s\n", gpg_strerror (rc)); + } + else if (skiderlen == 20) + { + log_printhex (skider, skiderlen, "ski might be the SHA-1:"); + } + else + { + if (DBG_X509) + log_debug(skider, skiderlen, "ski is:"); + } + ksba_free (ski); + } + } + gcry_md_close (md); gcry_sexp_release (s_sig); gcry_sexp_release (s_data); diff --git a/sm/certdump.c b/sm/certdump.c index ef60358d7..7d0dfdbf9 100644 --- a/sm/certdump.c +++ b/sm/certdump.c @@ -48,6 +48,28 @@ struct dn_array_s { }; +/* Get the first first element from the s-expression SN and return a + * pointer to it. Stores the length at R_LENGTH. Returns NULL for no + * value or an invalid expression. */ +const void * +gpgsm_get_serial (ksba_const_sexp_t sn, size_t *r_length) +{ + const char *p = (const char *)sn; + unsigned long n; + char *endp; + + if (!p || *p != '(') + return NULL; + p++; + n = strtoul (p, &endp, 10); + p = endp; + if (*p++ != ':') + return NULL; + *r_length = n; + return p; +} + + /* Print the first element of an S-Expression. */ void gpgsm_print_serial (estream_t fp, ksba_const_sexp_t sn) diff --git a/sm/gpgsm.h b/sm/gpgsm.h index 9c6f0e3d4..96da48221 100644 --- a/sm/gpgsm.h +++ b/sm/gpgsm.h @@ -297,6 +297,7 @@ char *gpgsm_get_certid (ksba_cert_t cert); /*-- certdump.c --*/ +const void *gpgsm_get_serial (ksba_const_sexp_t sn, size_t *r_length); void gpgsm_print_serial (estream_t fp, ksba_const_sexp_t p); void gpgsm_print_time (estream_t fp, ksba_isotime_t t); void gpgsm_print_name2 (FILE *fp, const char *string, int translate); |