commit 481fcfde93759dc77dfc3124a38feeaeaa2e73c5
author Manuel Pégourié-Gonnard <mpg@elzevir.fr> Thu Jul 03 16:12:50 2014 +0200
committer Paul Bakker <p.j.bakker@polarssl.org> Fri Jul 04 14:59:08 2014 +0200
tree 7552ca1dd6bf552704b52f4784d2fb4c54e1a407
parent cc10f4ddfe3ff71e8fa829aeecbf66efbd298997

Make PSK_LEN configurable and adjust PMS size

include/polarssl/config.h

diff --git a/include/polarssl/config.h b/include/polarssl/config.h
index e83518a..d43365f 100644
--- a/include/polarssl/config.h
+++ b/include/polarssl/config.h
@@ -2154,6 +2154,7 @@
 /* SSL options */
 //#define SSL_MAX_CONTENT_LEN             16384 /**< Size of the input / output buffer */
 //#define SSL_DEFAULT_TICKET_LIFETIME     86400 /**< Lifetime of session tickets (if enabled) */
+//#define POLARSSL_PSK_MAX_LEN               32 /**< Max size of TLS pre-shared keys, in bytes (default 256 bits) */
 
 /**
  * Complete list of ciphersuites to use, in order of preference.

include/polarssl/ssl.h

diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 9db0fc6..f1de499 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -34,6 +34,7 @@
 #endif
 #include "net.h"
 #include "bignum.h"
+#include "ecp.h"
 
 #include "ssl_ciphersuites.h"
 
@@ -409,12 +410,43 @@
 /*
  * Size defines
  */
-#if !defined(POLARSSL_MPI_MAX_SIZE)
-#define POLARSSL_PREMASTER_SIZE             512
-#else
-#define POLARSSL_PREMASTER_SIZE             POLARSSL_MPI_MAX_SIZE
+#if !defined(POLARSSL_PSK_MAX_LEN)
+#define POLARSSL_PSK_MAX_LEN            32 /* 256 bits */
 #endif
 
+/* Dummy type used only for its size */
+union _ssl_premaster_secret
+{
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)
+    unsigned char _pms_rsa[48];                         /* RFC 5246 8.1.1 */
+#endif
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED)
+    unsigned char _pms_dhm[POLARSSL_MPI_MAX_SIZE];      /* RFC 5246 8.1.2 */
+#endif
+#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED)    || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)  || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED)     || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+    unsigned char _pms_ecdh[POLARSSL_ECP_MAX_BYTES];    /* RFC 4492 5.10 */
+#endif
+#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED)
+    unsigned char _pms_psk[4 + 2 * POLARSSL_PSK_MAX_LEN];       /* RFC 4279 2 */
+#endif
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
+    unsigned char _pms_dhe_psk[4 + POLARSSL_MPI_MAX_SIZE
+                                 + POLARSSL_PSK_MAX_LEN];       /* RFC 4279 3 */
+#endif
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
+    unsigned char _pms_rsa_psk[52 + POLARSSL_PSK_MAX_LEN];      /* RFC 4279 4 */
+#endif
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
+    unsigned char _pms_ecdhe_psk[4 + POLARSSL_ECP_MAX_BYTES
+                                   + POLARSSL_PSK_MAX_LEN];     /* RFC 5489 2 */
+#endif
+};
+
+#define POLARSSL_PREMASTER_SIZE     sizeof( union _ssl_premaster_secret )
+
 #ifdef __cplusplus
 extern "C" {
 #endif

include/polarssl/ssl_ciphersuites.h

diff --git a/include/polarssl/ssl_ciphersuites.h b/include/polarssl/ssl_ciphersuites.h
index 5ecd5fe..c4f1ffe 100644
--- a/include/polarssl/ssl_ciphersuites.h
+++ b/include/polarssl/ssl_ciphersuites.h
@@ -233,6 +233,7 @@
 #define TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8      0xC0AE  /**< TLS 1.2 */
 #define TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8      0xC0AF  /**< TLS 1.2 */
 
+/* Reminder: update _ssl_premaster_secret when adding a new key exchange */
 typedef enum {
     POLARSSL_KEY_EXCHANGE_NONE = 0,
     POLARSSL_KEY_EXCHANGE_RSA,