diff options
| -rw-r--r-- | src/include/ipxe/tls.h | 1 | ||||
| -rw-r--r-- | src/net/tls.c | 246 |
2 files changed, 247 insertions, 0 deletions
diff --git a/src/include/ipxe/tls.h b/src/include/ipxe/tls.h index 80cdd12..6d6c82d 100644 --- a/src/include/ipxe/tls.h +++ b/src/include/ipxe/tls.h @@ -403,6 +403,7 @@ struct tls_connection { #define TLS_RX_ALIGN 16 extern struct tls_key_exchange_algorithm tls_pubkey_exchange_algorithm; +extern struct tls_key_exchange_algorithm tls_dhe_exchange_algorithm; extern int add_tls ( struct interface *xfer, const char *name, struct x509_root *root, struct private_key *key ); diff --git a/src/net/tls.c b/src/net/tls.c index b209e0d..4aa4d9e 100644 --- a/src/net/tls.c +++ b/src/net/tls.c @@ -49,6 +49,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #include <ipxe/rbg.h> #include <ipxe/validator.h> #include <ipxe/job.h> +#include <ipxe/dhe.h> #include <ipxe/tls.h> #include <config/crypto.h> @@ -109,6 +110,10 @@ FILE_LICENCE ( GPL2_OR_LATER ); #define EINFO_EINVAL_TICKET \ __einfo_uniqify ( EINFO_EINVAL, 0x0e, \ "Invalid New Session Ticket record") +#define EINVAL_KEY_EXCHANGE __einfo_error ( EINFO_EINVAL_KEY_EXCHANGE ) +#define EINFO_EINVAL_KEY_EXCHANGE \ + __einfo_uniqify ( EINFO_EINVAL, 0x0f, \ + "Invalid Server Key Exchange record" ) #define EIO_ALERT __einfo_error ( EINFO_EIO_ALERT ) #define EINFO_EIO_ALERT \ __einfo_uniqify ( EINFO_EIO, 0x01, \ @@ -177,6 +182,10 @@ FILE_LICENCE ( GPL2_OR_LATER ); #define EINFO_EPERM_RENEG_VERIFY \ __einfo_uniqify ( EINFO_EPERM, 0x05, \ "Secure renegotiation verification failed" ) +#define EPERM_KEY_EXCHANGE __einfo_error ( EINFO_EPERM_KEY_EXCHANGE ) +#define EINFO_EPERM_KEY_EXCHANGE \ + __einfo_uniqify ( EINFO_EPERM, 0x06, \ + "ServerKeyExchange verification failed" ) #define EPROTO_VERSION __einfo_error ( EINFO_EPROTO_VERSION ) #define EINFO_EPROTO_VERSION \ __einfo_uniqify ( EINFO_EPROTO, 0x01, \ @@ -915,6 +924,44 @@ tls_signature_hash_algorithm ( struct pubkey_algorithm *pubkey, return NULL; } +/** + * Find TLS signature algorithm + * + * @v code Signature and hash algorithm identifier + * @ret pubkey Public key algorithm, or NULL + */ +static struct pubkey_algorithm * +tls_signature_hash_pubkey ( struct tls_signature_hash_id code ) { + struct tls_signature_hash_algorithm *sig_hash; + + /* Identify signature and hash algorithm */ + for_each_table_entry ( sig_hash, TLS_SIG_HASH_ALGORITHMS ) { + if ( sig_hash->code.signature == code.signature ) + return sig_hash->pubkey; + } + + return NULL; +} + +/** + * Find TLS hash algorithm + * + * @v code Signature and hash algorithm identifier + * @ret digest Digest algorithm, or NULL + */ +static struct digest_algorithm * +tls_signature_hash_digest ( struct tls_signature_hash_id code ) { + struct tls_signature_hash_algorithm *sig_hash; + + /* Identify signature and hash algorithm */ + for_each_table_entry ( sig_hash, TLS_SIG_HASH_ALGORITHMS ) { + if ( sig_hash->code.hash == code.hash ) + return sig_hash->digest; + } + + return NULL; +} + /****************************************************************************** * * Handshake verification @@ -1278,6 +1325,205 @@ struct tls_key_exchange_algorithm tls_pubkey_exchange_algorithm = { }; /** + * Transmit Client Key Exchange record using DHE key exchange + * + * @v tls TLS connection + * @ret rc Return status code + */ +static int tls_send_client_key_exchange_dhe ( struct tls_connection *tls ) { + struct tls_cipherspec *cipherspec = &tls->tx_cipherspec_pending; + struct pubkey_algorithm *pubkey; + struct digest_algorithm *digest; + int use_sig_hash = tls_version ( tls, TLS_VERSION_TLS_1_2 ); + uint8_t private[ sizeof ( tls->client_random.random ) ]; + const struct { + uint16_t len; + uint8_t data[0]; + } __attribute__ (( packed )) *dh_val[3]; + const struct { + struct tls_signature_hash_id sig_hash[use_sig_hash]; + uint16_t signature_len; + uint8_t signature[0]; + } __attribute__ (( packed )) *sig; + const void *data; + size_t remaining; + size_t frag_len; + unsigned int i; + int rc; + + /* Parse ServerKeyExchange */ + data = tls->server_key; + remaining = tls->server_key_len; + for ( i = 0 ; i < ( sizeof ( dh_val ) / sizeof ( dh_val[0] ) ) ; i++ ){ + dh_val[i] = data; + if ( ( sizeof ( *dh_val[i] ) > remaining ) || + ( ntohs ( dh_val[i]->len ) > ( remaining - + sizeof ( *dh_val[i] ) ) )){ + DBGC ( tls, "TLS %p received underlength " + "ServerKeyExchange\n", tls ); + DBGC_HDA ( tls, 0, tls->server_key, + tls->server_key_len ); + rc = -EINVAL_KEY_EXCHANGE; + goto err_header; + } + frag_len = ( sizeof ( *dh_val[i] ) + ntohs ( dh_val[i]->len )); + data += frag_len; + remaining -= frag_len; + } + sig = data; + if ( ( sizeof ( *sig ) > remaining ) || + ( ntohs ( sig->signature_len ) > ( remaining - + sizeof ( *sig ) ) ) ) { + DBGC ( tls, "TLS %p received underlength ServerKeyExchange\n", + tls ); + DBGC_HDA ( tls, 0, tls->server_key, tls->server_key_len ); + rc = -EINVAL_KEY_EXCHANGE; + goto err_header; + } + + /* Identify signature and hash algorithm */ + if ( use_sig_hash ) { + pubkey = tls_signature_hash_pubkey ( sig->sig_hash[0] ); + digest = tls_signature_hash_digest ( sig->sig_hash[0] ); + if ( ( ! pubkey ) || ( ! digest ) ) { + DBGC ( tls, "TLS %p ServerKeyExchange unsupported " + "signature and hash algorithm\n", tls ); + rc = -ENOTSUP_SIG_HASH; + goto err_sig_hash; + } + if ( pubkey != cipherspec->suite->pubkey ) { + DBGC ( tls, "TLS %p ServerKeyExchange incorrect " + "signature algorithm %s (expected %s)\n", tls, + pubkey->name, cipherspec->suite->pubkey->name ); + rc = -EPERM_KEY_EXCHANGE; + goto err_sig_hash; + } + } else { + pubkey = cipherspec->suite->pubkey; + digest = &md5_sha1_algorithm; + } + + /* Verify signature */ + { + const void *signature = sig->signature; + size_t signature_len = ntohs ( sig->signature_len ); + uint8_t ctx[digest->ctxsize]; + uint8_t hash[digest->digestsize]; + + /* Calculate digest */ + digest_init ( digest, ctx ); + digest_update ( digest, ctx, &tls->client_random, + sizeof ( tls->client_random ) ); + digest_update ( digest, ctx, tls->server_random, + sizeof ( tls->server_random ) ); + digest_update ( digest, ctx, tls->server_key, + ( tls->server_key_len - remaining ) ); + digest_final ( digest, ctx, hash ); + + /* Verify signature */ + if ( ( rc = pubkey_verify ( pubkey, cipherspec->pubkey_ctx, + digest, hash, signature, + signature_len ) ) != 0 ) { + DBGC ( tls, "TLS %p ServerKeyExchange failed " + "verification\n", tls ); + DBGC_HDA ( tls, 0, tls->server_key, + tls->server_key_len ); + rc = -EPERM_KEY_EXCHANGE; + goto err_verify; + } + } + + /* Generate Diffie-Hellman private key */ + if ( ( rc = tls_generate_random ( tls, private, + sizeof ( private ) ) ) != 0 ) { + goto err_random; + } + + /* Construct pre-master secret and ClientKeyExchange record */ + { + typeof ( dh_val[0] ) dh_p = dh_val[0]; + typeof ( dh_val[1] ) dh_g = dh_val[1]; + typeof ( dh_val[2] ) dh_ys = dh_val[2]; + size_t len = ntohs ( dh_p->len ); + struct { + uint32_t type_length; + uint16_t dh_xs_len; + uint8_t dh_xs[len]; + } __attribute__ (( packed )) *key_xchg; + struct { + uint8_t pre_master_secret[len]; + typeof ( *key_xchg ) key_xchg; + } *dynamic; + uint8_t *pre_master_secret; + + /* Allocate space */ + dynamic = malloc ( sizeof ( *dynamic ) ); + if ( ! dynamic ) { + rc = -ENOMEM; + goto err_alloc; + } + pre_master_secret = dynamic->pre_master_secret; + key_xchg = &dynamic->key_xchg; + key_xchg->type_length = + ( cpu_to_le32 ( TLS_CLIENT_KEY_EXCHANGE ) | + htonl ( sizeof ( *key_xchg ) - + sizeof ( key_xchg->type_length ) ) ); + key_xchg->dh_xs_len = htons ( len ); + + /* Calculate pre-master secret and client public value */ + if ( ( rc = dhe_key ( dh_p->data, len, + dh_g->data, ntohs ( dh_g->len ), + dh_ys->data, ntohs ( dh_ys->len ), + private, sizeof ( private ), + key_xchg->dh_xs, + pre_master_secret ) ) != 0 ) { + DBGC ( tls, "TLS %p could not calculate DHE key: %s\n", + tls, strerror ( rc ) ); + goto err_dhe_key; + } + + /* Strip leading zeroes from pre-master secret */ + while ( len && ( ! *pre_master_secret ) ) { + pre_master_secret++; + len--; + } + + /* Generate master secret */ + tls_generate_master_secret ( tls, pre_master_secret, len ); + + /* Generate keys */ + if ( ( rc = tls_generate_keys ( tls ) ) != 0 ) { + DBGC ( tls, "TLS %p could not generate keys: %s\n", + tls, strerror ( rc ) ); + goto err_generate_keys; + } + + /* Transmit Client Key Exchange record */ + if ( ( rc = tls_send_handshake ( tls, key_xchg, + sizeof ( *key_xchg ) ) ) !=0){ + goto err_send_handshake; + } + + err_send_handshake: + err_generate_keys: + err_dhe_key: + free ( dynamic ); + } + err_alloc: + err_random: + err_verify: + err_sig_hash: + err_header: + return rc; +} + +/** Ephemeral Diffie-Hellman key exchange algorithm */ +struct tls_key_exchange_algorithm tls_dhe_exchange_algorithm = { + .name = "dhe", + .exchange = tls_send_client_key_exchange_dhe, +}; + +/** * Transmit Client Key Exchange record * * @v tls TLS connection |