[PATCH 5/7] tls: Update l_tls to use the l_cert type, drop local code

Drop the remaining struct tls_cert code and use the l_cert type for all the certificate operations. tls_cert_load_file is temporarily left in tls.c but my idea is to replace it with two new pem.c functions, although test-key.c will still need it. tls_cert_from_certificate_list is only renamed to tls_parse_certificate_list as it is TLS-specific. --- ell/tls-private.h | 29 ++---- ell/tls-record.c | 1 + ell/tls.c | 244 +++++++++++++++++++++------------------------- 3 files changed, 119 insertions(+), 155 deletions(-) diff --git a/ell/tls-private.h b/ell/tls-private.h index 7dfbd6c..9c909e1 100644 --- a/ell/tls-private.h +++ b/ell/tls-private.h @@ -28,8 +28,6 @@ #define TLS_VERSION TLS_V12 #define TLS_MIN_VERSION TLS_V10 -struct tls_cert; - enum tls_cipher_type { TLS_CIPHER_STREAM, TLS_CIPHER_BLOCK, @@ -65,7 +63,7 @@ struct tls_key_exchange_algorithm { bool certificate_check; - bool (*validate_cert_key_type)(struct tls_cert *cert); + bool (*validate_cert_key_type)(struct l_cert *cert); bool (*send_client_key_exchange)(struct l_tls *tls); void (*handle_client_key_exchange)(struct l_tls *tls, @@ -147,8 +145,8 @@ struct l_tls { l_tls_destroy_cb_t debug_destroy; void *debug_data; - char *ca_cert_path; - char *cert_path; + struct l_cert *ca_cert; + struct l_certchain *cert; struct l_key *priv_key; size_t priv_key_size; @@ -174,7 +172,7 @@ struct l_tls { uint16_t negotiated_version; bool cert_requested, cert_sent; bool peer_authenticated; - struct tls_cert *peer_cert; + struct l_cert *peer_cert; struct l_key *peer_pubkey; size_t peer_pubkey_size; enum handshake_hash_type signature_hash; @@ -238,22 +236,9 @@ void tls_tx_record(struct l_tls *tls, enum tls_content_type type, bool tls_handle_message(struct l_tls *tls, const uint8_t *message, int len, enum tls_content_type type, uint16_t version); -/* X509 Certificates and Certificate Chains */ - -struct tls_cert { - size_t size; - struct tls_cert *issuer; - uint8_t asn1[0]; -}; - -enum tls_cert_key_type { - TLS_CERT_KEY_RSA, - TLS_CERT_KEY_UNKNOWN, -}; - -struct tls_cert *tls_cert_load_file(const char *filename); -int tls_cert_from_certificate_list(const void *data, size_t len, - struct tls_cert **out_certchain); +struct l_cert *tls_cert_load_file(const char *filename); +int tls_parse_certificate_list(const void *data, size_t len, + struct l_certchain **out_certchain); #define TLS_DEBUG(fmt, args...) \ l_util_debug(tls->debug_handler, tls->debug_data, "%s:%i " fmt, \ diff --git a/ell/tls-record.c b/ell/tls-record.c index a8ff696..73be1a4 100644 --- a/ell/tls-record.c +++ b/ell/tls-record.c @@ -29,6 +29,7 @@ #include "tls.h" #include "checksum.h" #include "cipher.h" +#include "cert.h" #include "tls-private.h" #include "random.h" diff --git a/ell/tls.c b/ell/tls.c index c0a2516..72d9b3e 100644 --- a/ell/tls.c +++ b/ell/tls.c @@ -35,9 +35,10 @@ #include "cipher.h" #include "random.h" #include "pem.h" +#include "cert.h" +#include "cert-private.h" #include "tls-private.h" #include "key.h" -#include "asn1-private.h" void tls10_prf(const void *secret, size_t secret_len, const char *label, @@ -172,7 +173,7 @@ static void tls_reset_handshake(struct l_tls *tls) memset(tls->pending.key_block, 0, sizeof(tls->pending.key_block)); - l_free(tls->peer_cert); + l_cert_free(tls->peer_cert); l_key_free(tls->peer_pubkey); tls->peer_cert = NULL; @@ -372,9 +373,9 @@ static ssize_t tls_rsa_sign(struct l_tls *tls, uint8_t *out, size_t len, static bool tls_rsa_verify(struct l_tls *tls, const uint8_t *in, size_t len, tls_get_hash_t get_hash); -static bool tls_rsa_validate_cert_key(struct tls_cert *cert) +static bool tls_rsa_validate_cert_key(struct l_cert *cert) { - return tls_cert_get_pubkey_type(cert) == TLS_CERT_KEY_RSA; + return l_cert_get_pubkey_type(cert) == L_CERT_KEY_RSA; } static struct tls_key_exchange_algorithm tls_rsa = { @@ -919,39 +920,56 @@ static void tls_send_server_hello(struct l_tls *tls) tls_tx_handshake(tls, TLS_SERVER_HELLO, buf, ptr - buf); } +static bool tls_cert_list_add_size(struct l_cert *cert, void *user_data) +{ + size_t *total = user_data; + size_t der_len; + + l_cert_get_der_data(cert, &der_len); + *total += 3 + der_len; + + return false; +} + +static bool tls_cert_list_append(struct l_cert *cert, void *user_data) +{ + uint8_t **ptr = user_data; + const uint8_t *der; + size_t der_len; + + der = l_cert_get_der_data(cert, &der_len); + *(*ptr)++ = der_len >> 16; + *(*ptr)++ = der_len >> 8; + *(*ptr)++ = der_len >> 0; + memcpy(*ptr, der, der_len); + *ptr += der_len; + + return false; +} + static bool tls_send_certificate(struct l_tls *tls) { uint8_t *buf, *ptr; - struct tls_cert *cert, *i; size_t total; + struct l_cert *leaf; - if (tls->cert_path) - cert = tls_cert_load_file(tls->cert_path); - else - cert = NULL; - - if (tls->server && !cert) { + if (tls->server && !tls->cert) { TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, TLS_ALERT_BAD_CERT, - "Loading server certificate %s failed", - tls->cert_path); + "Certificate needed in server mode"); return false; } - if (cert && !tls_cert_find_certchain(cert, tls->ca_cert_path)) { - if (tls->server) { - TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, - TLS_ALERT_UNKNOWN_CA, - "Can't find certificate chain local " - "CA cert %s", tls->ca_cert_path); - - return false; - } else - cert = NULL; + if (tls->cert && !l_certchain_find(tls->cert, tls->ca_cert)) { + TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, TLS_ALERT_UNKNOWN_CA, + "Can't find certificate chain to local " + "CA cert"); + return false; } /* TODO: might want check this earlier and exclude the cipher suite */ - if (cert && !tls->pending.cipher_suite->key_xchg-> - validate_cert_key_type(cert)) { + leaf = l_certchain_get_leaf(tls->cert); + if (leaf && !tls->pending.cipher_suite->key_xchg-> + validate_cert_key_type(leaf)) { TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, TLS_ALERT_CERT_UNKNOWN, "Local certificate has key type incompatible " "with pending cipher suite %s", @@ -978,8 +996,7 @@ static bool tls_send_certificate(struct l_tls *tls) */ total = 0; - for (i = cert; i; i = i->issuer) - total += 3 + i->size; + l_certchain_foreach_from_leaf(tls->cert, tls_cert_list_add_size, &total); buf = l_malloc(128 + total); ptr = buf + TLS_HANDSHAKE_HEADER_SIZE; @@ -989,25 +1006,15 @@ static bool tls_send_certificate(struct l_tls *tls) *ptr++ = total >> 16; *ptr++ = total >> 8; *ptr++ = total >> 0; - - for (i = cert; i; i = i->issuer) { - *ptr++ = i->size >> 16; - *ptr++ = i->size >> 8; - *ptr++ = i->size >> 0; - - memcpy(ptr, i->asn1, i->size); - ptr += i->size; - } + l_certchain_foreach_from_leaf(tls->cert, tls_cert_list_append, &ptr); tls_tx_handshake(tls, TLS_CERTIFICATE, buf, ptr - buf); l_free(buf); - if (cert) + if (tls->cert) tls->cert_sent = true; - l_free(cert); - return true; } @@ -1644,21 +1651,20 @@ static void tls_handle_client_hello(struct l_tls *tls, tls_send_server_hello(tls); - if (tls->pending.cipher_suite->key_xchg->certificate_check && - tls->cert_path) + if (tls->pending.cipher_suite->key_xchg->certificate_check && tls->cert) if (!tls_send_certificate(tls)) return; /* TODO: don't bother if configured to not authenticate client */ if (tls->pending.cipher_suite->key_xchg->certificate_check && - tls->ca_cert_path) + tls->ca_cert) if (!tls_send_certificate_request(tls)) return; tls_send_server_hello_done(tls); if (tls->pending.cipher_suite->key_xchg->certificate_check && - tls->ca_cert_path) + tls->ca_cert) TLS_SET_STATE(TLS_HANDSHAKE_WAIT_CERTIFICATE); else TLS_SET_STATE(TLS_HANDSHAKE_WAIT_KEY_EXCHANGE); @@ -1772,8 +1778,10 @@ static void tls_handle_certificate(struct l_tls *tls, const uint8_t *buf, size_t len) { size_t total; - struct tls_cert *certchain = NULL; - struct tls_cert *ca_cert = NULL; + struct l_certchain *certchain = NULL; + struct l_cert *leaf; + size_t der_len; + const uint8_t *der; bool dummy; if (len < 3) @@ -1786,7 +1794,7 @@ static void tls_handle_certificate(struct l_tls *tls, if (total + 3 != len) goto decode_error; - if (tls_cert_from_certificate_list(buf, total, &certchain) < 0) { + if (tls_parse_certificate_list(buf, total, &certchain) < 0) { TLS_DISCONNECT(TLS_ALERT_DECODE_ERROR, 0, "Error decoding peer certificate chain"); @@ -1818,22 +1826,11 @@ static void tls_handle_certificate(struct l_tls *tls, * Validate the certificate chain's consistency and validate it * against our CA if we have any. */ - - if (tls->ca_cert_path) { - ca_cert = tls_cert_load_file(tls->ca_cert_path); - if (!ca_cert) { - TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, - TLS_ALERT_BAD_CERT, - "Can't load %s", tls->ca_cert_path); - - goto done; - } - } - - if (!tls_cert_verify_certchain(certchain, ca_cert)) { + if (!l_certchain_verify(certchain, tls->ca_cert)) { TLS_DISCONNECT(TLS_ALERT_BAD_CERT, 0, - "Peer certchain verification failed against " - "CA cert %s", tls->ca_cert_path); + "Peer certchain verification failed " + "consistency check%s", + tls->ca_cert ? " or against local CA cert" : ""); goto done; } @@ -1844,8 +1841,9 @@ static void tls_handle_certificate(struct l_tls *tls, * restrictions) MUST be compatible with the selected key exchange * algorithm." */ + leaf = l_certchain_get_leaf(certchain); if (!tls->pending.cipher_suite->key_xchg-> - validate_cert_key_type(certchain)) { + validate_cert_key_type(leaf)) { TLS_DISCONNECT(TLS_ALERT_UNSUPPORTED_CERT, 0, "Peer certificate key type incompatible with " "pending cipher suite %s", @@ -1854,15 +1852,11 @@ static void tls_handle_certificate(struct l_tls *tls, goto done; } - /* Save the end-entity cert and free the rest of the chain */ - tls->peer_cert = certchain; - tls_cert_free_certchain(certchain->issuer); - certchain->issuer = NULL; - certchain = NULL; - - tls->peer_pubkey = l_key_new(L_KEY_RSA, tls->peer_cert->asn1, - tls->peer_cert->size); + /* Save the end-entity certificate and free the chain */ + der = l_cert_get_der_data(leaf, &der_len); + tls->peer_cert = l_cert_new_from_der(der, der_len); + tls->peer_pubkey = l_cert_get_pubkey(tls->peer_cert); if (!tls->peer_pubkey) { TLS_DISCONNECT(TLS_ALERT_UNSUPPORTED_CERT, 0, "Error loading peer public key to kernel"); @@ -1893,10 +1887,7 @@ decode_error: "TLS_CERTIFICATE decode error"); done: - if (ca_cert) - l_free(ca_cert); - - tls_cert_free_certchain(certchain); + l_certchain_free(certchain); } static void tls_handle_certificate_request(struct l_tls *tls, @@ -2148,8 +2139,8 @@ static void tls_handle_certificate_verify(struct l_tls *tls, * - If we received an (expected) Certificate Verify, we must have * sent a Certificate Request. * - If we sent a Certificate Request that's because - * tls->ca_cert_path is non-NULL. - * - If tls->ca_cert_path is non-NULL then tls_handle_certificate + * tls->ca_cert is non-NULL. + * - If tls->ca_cert is non-NULL then tls_handle_certificate * will have checked the whole certificate chain to be valid and * additionally trusted by our CA if known. * - Additionally cipher_suite->key_xchg->verify has just confirmed @@ -2361,7 +2352,7 @@ static void tls_handle_handshake(struct l_tls *tls, int type, /* * On the client, the server's certificate is only now * verified, based on the following logic: - * - tls->ca_cert_path is non-NULL so tls_handle_certificate + * - tls->ca_cert is non-NULL so tls_handle_certificate * (always called on the client) must have veritifed the * server's certificate chain to be valid and additionally * trusted by our CA. @@ -2374,8 +2365,7 @@ static void tls_handle_handshake(struct l_tls *tls, int type, * message (either should be enough). */ if (!tls->server && tls->cipher_suite[0]->key_xchg-> - certificate_check && - tls->ca_cert_path) + certificate_check && tls->ca_cert) tls->peer_authenticated = true; tls_finished(tls); @@ -2608,9 +2598,9 @@ LIB_EXPORT bool l_tls_set_cacert(struct l_tls *tls, const char *ca_cert_path) { TLS_DEBUG("ca-cert-path=%s", ca_cert_path); - if (tls->ca_cert_path) { - l_free(tls->ca_cert_path); - tls->ca_cert_path = NULL; + if (tls->ca_cert) { + l_cert_free(tls->ca_cert); + tls->ca_cert = NULL; } if (ca_cert_path) { @@ -2620,7 +2610,11 @@ LIB_EXPORT bool l_tls_set_cacert(struct l_tls *tls, const char *ca_cert_path) return false; } - tls->ca_cert_path = l_strdup(ca_cert_path); + tls->ca_cert = tls_cert_load_file(ca_cert_path); + if (!tls->ca_cert) { + TLS_DEBUG("Error loading %s", ca_cert_path); + return false; + } } return true; @@ -2633,9 +2627,9 @@ LIB_EXPORT bool l_tls_set_auth_data(struct l_tls *tls, const char *cert_path, TLS_DEBUG("cert-path=%s priv-key-path=%s priv-key-passphrase=%p", cert_path, priv_key_path, priv_key_passphrase); - if (tls->cert_path) { - l_free(tls->cert_path); - tls->cert_path = NULL; + if (tls->cert) { + l_certchain_free(tls->cert); + tls->cert = NULL; } if (tls->priv_key) { @@ -2644,6 +2638,17 @@ LIB_EXPORT bool l_tls_set_auth_data(struct l_tls *tls, const char *cert_path, tls->priv_key_size = 0; } + if (cert_path) { + struct l_cert *cert = tls_cert_load_file(cert_path); + + if (!cert) { + TLS_DEBUG("Error loading %s", cert_path); + return false; + } + + tls->cert = certchain_new_from_leaf(cert); + } + if (priv_key_path) { uint8_t *priv_key; bool is_public = true; @@ -2676,9 +2681,6 @@ LIB_EXPORT bool l_tls_set_auth_data(struct l_tls *tls, const char *cert_path, tls->priv_key_size /= 8; } - if (cert_path) - tls->cert_path = l_strdup(cert_path); - return true; } @@ -2759,59 +2761,29 @@ const char *tls_handshake_state_to_str(enum tls_handshake_state state) return buf; } -/* X509 Certificates and Certificate Chains */ - -#define X509_CERTIFICATE_POS 0 -#define X509_TBSCERTIFICATE_POS 0 -#define X509_TBSCERT_VERSION_POS 0 -#define X509_TBSCERT_SERIAL_POS 1 -#define X509_TBSCERT_SIGNATURE_POS 2 -#define X509_ALGORITHM_ID_ALGORITHM_POS 0 -#define X509_ALGORITHM_ID_PARAMS_POS 1 -#define X509_TBSCERT_ISSUER_DN_POS 3 -#define X509_TBSCERT_VALIDITY_POS 4 -#define X509_TBSCERT_SUBJECT_DN_POS 5 -#define X509_TBSCERT_SUBJECT_KEY_POS 6 -#define X509_SUBJECT_KEY_ALGORITHM_POS 0 -#define X509_SUBJECT_KEY_VALUE_POS 1 -#define X509_TBSCERT_ISSUER_UID_POS 7 -#define X509_TBSCERT_SUBJECT_UID_POS 8 -#define X509_TBSCERT_EXTENSIONS_POS 9 -#define X509_SIGNATURE_ALGORITHM_POS 1 -#define X509_SIGNATURE_VALUE_POS 2 - -struct tls_cert *tls_cert_load_file(const char *filename) +struct l_cert *tls_cert_load_file(const char *filename) { uint8_t *der; size_t len; - struct tls_cert *cert; + struct l_cert *cert; der = l_pem_load_certificate(filename, &len); if (!der) return NULL; - if (!len || der[0] != ASN1_ID_SEQUENCE) { - l_free(der); - return NULL; - } - - cert = l_malloc(sizeof(struct tls_cert) + len); - cert->size = len; - cert->issuer = NULL; - memcpy(cert->asn1, der, len); - + cert = l_cert_new_from_der(der, len); l_free(der); - return cert; } -int tls_cert_from_certificate_list(const void *data, size_t len, - struct tls_cert **out_certchain) +int tls_parse_certificate_list(const void *data, size_t len, + struct l_certchain **out_certchain) { const uint8_t *buf = data; - struct tls_cert *certchain = NULL, **tail = &certchain; + struct l_certchain *chain = NULL; while (len) { + struct l_cert *cert; size_t cert_len; if (len < 3) @@ -2824,24 +2796,30 @@ int tls_cert_from_certificate_list(const void *data, size_t len, if (cert_len + 3 > len) goto decode_error; - *tail = l_malloc(sizeof(struct tls_cert) + cert_len); - (*tail)->size = cert_len; - (*tail)->issuer = NULL; - memcpy((*tail)->asn1, buf, cert_len); + cert = l_cert_new_from_der(buf, cert_len); + if (!cert) + goto decode_error; - tail = &(*tail)->issuer; + if (!chain) { + chain = certchain_new_from_leaf(cert); + if (!chain) + goto decode_error; + } else + certchain_link_issuer(chain, cert); buf += cert_len; len -= cert_len + 3; } if (out_certchain) - *out_certchain = certchain; + *out_certchain = chain; + else + l_certchain_free(chain); return 0; decode_error: - tls_cert_free_certchain(certchain); + l_certchain_free(chain); return -EBADMSG; } -- 2.19.1