dtls.c: add cipher_suite_param_t

Use cipher_suite_param_t for cipher-suite specific mac_len and key_exchange_algorithm. Introduce dtls_cipher_index_t for simplified cipher-suite parameter lookup. Cleanup old functions. Signed-off-by: Achim Kraus <[email protected]>
eclipse · Aug 8, 2022 · 3cab03f · 3cab03f
1 parent 372e9bd
commit 3cab03f
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Showing 3 changed files with 220 additions and 181 deletions.
diff --git a/crypto.c b/crypto.c
@@ -157,12 +157,14 @@ dtls_handshake_parameters_t *dtls_handshake_new(void)
 
   memset(handshake, 0, sizeof(*handshake));
 
-  /* initialize the handshake hash wrt. the hard-coded DTLS version */
-  dtls_debug("DTLSv12: initialize HASH_SHA256\n");
-  /* TLS 1.2:  PRF(secret, label, seed) = P_<hash>(secret, label + seed) */
-  /* FIXME: we use the default SHA256 here, might need to support other
-            hash functions as well */
-  dtls_hash_init(&handshake->hs_state.hs_hash);
+  if (handshake) {
+    /* initialize the handshake hash wrt. the hard-coded DTLS version */
+    dtls_debug("DTLSv12: initialize HASH_SHA256\n");
+    /* TLS 1.2:  PRF(secret, label, seed) = P_<hash>(secret, label + seed) */
+    /* FIXME: we use the default SHA256 here, might need to support other 
+              hash functions as well */
+    dtls_hash_init(&handshake->hs_state.hs_hash);
+  }
   return handshake;
 }
 
@@ -187,7 +189,7 @@ dtls_security_parameters_t *dtls_security_new(void)
 
   memset(security, 0, sizeof(*security));
 
-  security->cipher = TLS_NULL_WITH_NULL_NULL;
+  security->cipher_index = DTLS_CIPHER_INDEX_NULL;
   security->compression = TLS_COMPRESSION_NULL;
 
   return security;

diff --git a/crypto.h b/crypto.h
@@ -49,6 +49,12 @@
 #define DTLS_MASTER_SECRET_LENGTH 48
 #define DTLS_RANDOM_LENGTH 32
 
+/** Type of index in cipher parameter table */
+typedef uint8_t dtls_cipher_index_t;
+/** Index in cipher parameter table for NULL cipher */
+#define DTLS_CIPHER_INDEX_NULL 0
+
+
 typedef enum { AES128=0 
 } dtls_crypto_alg;
 
@@ -105,7 +111,7 @@ typedef struct {
 typedef struct {
   dtls_compression_t compression;	/**< compression method */
 
-  dtls_cipher_t cipher;		/**< cipher type */
+  dtls_cipher_index_t cipher_index;	/**< internal index for cipher_suite_params, DTLS_CIPHER_INDEX_NULL for TLS_NULL_WITH_NULL_NULL */
   uint16_t epoch;	     /**< counter for cipher state changes*/
   uint64_t rseq;	     /**< sequence number of last record sent */
 
@@ -135,7 +141,7 @@ typedef struct {
   dtls_hs_state_t hs_state;  /**< handshake protocol status */
 
   dtls_compression_t compression;		/**< compression method */
-  dtls_cipher_t cipher;		/**< cipher type */
+  dtls_cipher_index_t cipher_index;		/**< internal index for cipher_suite_params, DTLS_CIPHER_INDEX_NULL for TLS_NULL_WITH_NULL_NULL */
   unsigned int do_client_auth:1;
   unsigned int extended_master_secret:1;
   union {