From 2a9060bba62d78f73da9b09ca791fe80993520fc Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Thu, 6 Oct 2011 15:32:12 +0200 Subject: [PATCH] Exchange ACK records to indicate switch to new keys. This allow application records to be sent while key renegotiation is still happening. --- src/sptps.c | 48 ++++++++++++++++++++++++++++++++++-------------- src/sptps.h | 19 ++++++++++++------- 2 files changed, 46 insertions(+), 21 deletions(-) diff --git a/src/sptps.c b/src/sptps.c index dbb54248..d22390e8 100644 --- a/src/sptps.c +++ b/src/sptps.c @@ -191,10 +191,27 @@ static bool send_ack(sptps_t *s) { // Receive an ACKnowledgement record. static bool receive_ack(sptps_t *s, const char *data, uint16_t len) { if(len) - return false; + return error(s, EIO, "Invalid ACK record length"); + + if(s->initiator) { + bool result + = cipher_set_counter_key(&s->incipher, s->key) + && digest_set_key(&s->indigest, s->key + cipher_keylength(&s->incipher), digest_keylength(&s->indigest)); + if(!result) + return false; + } else { + bool result + = cipher_set_counter_key(&s->incipher, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest)) + && digest_set_key(&s->indigest, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest) + cipher_keylength(&s->incipher), digest_keylength(&s->indigest)); + if(!result) + return false; + } - // TODO: set cipher/digest keys - return error(s, ENOSYS, "receive_ack() not completely implemented yet"); + free(s->key); + s->key = NULL; + s->instate = true; + + return true; } // Receive a Key EXchange record, respond by sending a SIG record. @@ -244,31 +261,32 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) { if(!generate_key_material(s, shared, sizeof shared)) return false; - // Send cipher change record if necessary - //if(s->outstate && !send_ack(s)) - // return false; + free(s->mykex); + free(s->hiskex); + + s->mykex = NULL; + s->hiskex = NULL; + + // Send cipher change record + if(!send_ack(s)) + return false; // TODO: only set new keys after ACK has been set/received if(s->initiator) { bool result - = cipher_set_counter_key(&s->incipher, s->key) - && digest_set_key(&s->indigest, s->key + cipher_keylength(&s->incipher), digest_keylength(&s->indigest)) - && cipher_set_counter_key(&s->outcipher, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest)) + = cipher_set_counter_key(&s->outcipher, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest)) && digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest) + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest)); if(!result) return false; } else { bool result = cipher_set_counter_key(&s->outcipher, s->key) - && digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest)) - && cipher_set_counter_key(&s->incipher, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest)) - && digest_set_key(&s->indigest, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest) + cipher_keylength(&s->incipher), digest_keylength(&s->indigest)); + && digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest)); if(!result) return false; } s->outstate = true; - s->instate = true; return true; } @@ -302,7 +320,7 @@ static bool receive_handshake(sptps_t *s, const char *data, uint16_t len) { if(!receive_sig(s, data, len)) return false; // s->state = SPTPS_ACK; - s->state = SPTPS_SECONDARY_KEX; + s->state = SPTPS_ACK; return true; case SPTPS_ACK: // We expect a handshake message to indicate transition to the new keys. @@ -389,6 +407,8 @@ bool receive_data(sptps_t *s, const char *data, size_t len) { // Handle record. if(type < SPTPS_HANDSHAKE) { + if(!s->instate) + return error(s, EIO, "Application record received before handshake finished"); if(!s->receive_record(s->handle, type, s->inbuf + 7, reclen)) return false; } else if(type == SPTPS_HANDSHAKE) { diff --git a/src/sptps.h b/src/sptps.h index 6eb933c4..51de5753 100644 --- a/src/sptps.h +++ b/src/sptps.h @@ -24,13 +24,18 @@ #include "ecdh.h" #include "ecdsa.h" -#define SPTPS_KEX 0 -#define SPTPS_SECONDARY_KEX 1 // Waiting for peer's ECDHE pubkey -#define SPTPS_SIG 2 // Waiting for peer's ECDHE pubkey -#define SPTPS_ACK 3 // Waiting for peer's acknowledgement of pubkey reception - -#define SPTPS_HANDSHAKE 128 -#define SPTPS_VERSION 128 +#define SPTPS_VERSION 0 + +// Record types +#define SPTPS_HANDSHAKE 128 // Key exchange and authentication +#define SPTPS_ALERT 129 // Warning or error messages +#define SPTPS_CLOSE 130 // Application closed the connection + +// Key exchange states +#define SPTPS_KEX 0 // Waiting for the first Key EXchange record +#define SPTPS_SECONDARY_KEX 1 // Ready to receive a secondary Key EXchange record +#define SPTPS_SIG 2 // Waiting for a SIGnature record +#define SPTPS_ACK 3 // Waiting for an ACKnowledgement record typedef bool (*send_data_t)(void *handle, const char *data, size_t len); typedef bool (*receive_record_t)(void *handle, uint8_t type, const char *data, uint16_t len); -- 2.39.2