Use old PRF functions if SSL_export_keying_material() fails.

Because https://tools.ietf.org/html/rfc5705#section-6

says that certain labels are prohibited, and OpenSSL enforces
that prohibition.

We need the keys for EAP, so we have to *always* implement the
functions.  Because SSL_export_keying_material() might fail.

We'll need a later commit to implement the TLS 1.2 PRF.

diff --git a/src/modules/rlm_eap/libeap/mppe_keys.c b/src/modules/rlm_eap/libeap/mppe_keys.c
index 0265a1f153ce7e3ec27406ae97a34ef679d24d37..4be125391fd0f372bf0a7d8df2a3856bbc0df4cc 100644 (file)
--- a/src/modules/rlm_eap/libeap/mppe_keys.c
+++ b/src/modules/rlm_eap/libeap/mppe_keys.c
@@ -29,7 +29,6 @@ USES_APPLE_DEPRECATED_API     /* OpenSSL API has been deprecated by Apple */
 #include <openssl/hmac.h>
 
 
-#if OPENSSL_VERSION_NUMBER < 0x10001000L
 /*
  * TLS PRF from RFC 2246
  */
@@ -98,7 +97,6 @@ static void PRF(unsigned char const *secret, unsigned int secret_len,
                out[i] ^= buf[i];
        }
 }
-#endif
 
 #define EAPTLS_MPPE_KEY_LEN     32
 
@@ -118,7 +116,8 @@ void eap_tls_gen_mppe_keys(REQUEST *request, SSL *s, char const *prf_label)
                ERROR("Failed generating keying material");
                return;
        }
-#else
+#endif
+
        {
                uint8_t seed[64 + (2 * SSL3_RANDOM_SIZE)];
                uint8_t buf[4 * EAPTLS_MPPE_KEY_LEN];
@@ -138,7 +137,6 @@ void eap_tls_gen_mppe_keys(REQUEST *request, SSL *s, char const *prf_label)
                PRF(s->session->master_key, s->session->master_key_length,
                    seed, prf_size, out, buf, sizeof(out));
        }
-#endif
 
        RDEBUG2("Adding session keys");
        p = out;
@@ -159,16 +157,17 @@ void eap_tls_gen_mppe_keys(REQUEST *request, SSL *s, char const *prf_label)
  */
 void eap_tls_gen_challenge(SSL *s, uint8_t *buffer, size_t size, char const *prf_label)
 {
-#if OPENSSL_VERSION_NUMBER >= 0x10001000L
-       SSL_export_keying_material(s, buffer, size, prf_label,
-                                  strlen(prf_label), NULL, 0, 0);
-
-#else
        uint8_t out[32], buf[32];
        uint8_t seed[128 + 2*SSL3_RANDOM_SIZE];
        uint8_t *p = seed;
        size_t len;
 
+#if OPENSSL_VERSION_NUMBER >= 0x10001000L
+       if (SSL_export_keying_material(s, buffer, size, prf_label,
+                                      strlen(prf_label), NULL, 0, 0) == 1) return;
+
+#endif
+
        len = strlen(prf_label);
        if (len > 128) len = 128;
 
@@ -182,7 +181,6 @@ void eap_tls_gen_challenge(SSL *s, uint8_t *buffer, size_t size, char const *prf
        PRF(s->session->master_key, s->session->master_key_length,
            seed, p - seed, out, buf, sizeof(out));
        memcpy(buffer, out, size);
-#endif
 }
 
 /*