Avoid -E and -M options inconsistencies with no libcrypto

[tcpdump] / print-esp.c

diff --git a/print-esp.c b/print-esp.c
index 834dd7411be158430514782c7780b2ff2f52fed9..d89fefbe3fbb86c3959282c575fdabb755131879 100644 (file)
--- a/print-esp.c
+++ b/print-esp.c
@@ -425,6 +425,7 @@ espprint_decode_encalgo(netdissect_options *ndo,
        const EVP_CIPHER *evp;
        int authlen = 0;
        char *colon, *p;
+       const char *real_decode;
 
        colon = strchr(decode, ':');
        if (colon == NULL) {
@@ -445,10 +446,23 @@ espprint_decode_encalgo(netdissect_options *ndo,
                p = strstr(decode, "-cbc");
                *p = '\0';
        }
-       evp = EVP_get_cipherbyname(decode);
+       /*
+        * Not all versions of libcrypto support calls to add aliases
+        * to ciphers - newer versions of libressl don't - so, instead
+        * of making "3des" an alias for "des_ede3_cbc", if attempting
+        * to get the cipher fails and the name is "3des", we try
+        * "des_ede3_cbc".
+        */
+       real_decode = decode;
+       if (strcmp(real_decode, "3des") == 0)
+               real_decode = "des-ede3-cbc";
+       evp = EVP_get_cipherbyname(real_decode);
 
        if (!evp) {
-               (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s\n", decode);
+               if (decode != real_decode)
+                       (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s (%s)\n", real_decode, decode);
+               else
+                       (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s\n", decode);
                sa->evp = NULL;
                sa->authlen = 0;
                sa->ivlen = 0;
@@ -684,7 +698,6 @@ static void esp_init(netdissect_options *ndo _U_)
 #if !defined(OPENSSL_API_COMPAT) || OPENSSL_API_COMPAT < 0x10100000L
        OpenSSL_add_all_algorithms();
 #endif
-       EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
 }
 DIAG_ON_DEPRECATION
 
@@ -734,8 +747,8 @@ esp_print(netdissect_options *ndo,
          u_int ttl_hl USED_IF_LIBCRYPTO)
 {
        const struct newesp *esp;
-       const u_char *ep;
 #ifdef HAVE_LIBCRYPTO
+       const u_char *ep;
        const struct ip *ip;
        struct sa_list *sa = NULL;
        const struct ip6_hdr *ip6 = NULL;
@@ -751,18 +764,16 @@ esp_print(netdissect_options *ndo,
        ndo->ndo_protocol = "esp";
        esp = (const struct newesp *)bp;
 
-       /* 'ep' points to the end of available data. */
-       ep = ndo->ndo_snapend;
+       nd_print_protocol_caps(ndo);
 
-       if ((const u_char *)(esp + 1) >= ep) {
-               nd_print_trunc(ndo);
-               return;
-       }
-       ND_PRINT("ESP(spi=0x%08x", GET_BE_U_4(esp->esp_spi));
+       ND_PRINT("(spi=0x%08x", GET_BE_U_4(esp->esp_spi));
        ND_PRINT(",seq=0x%x)", GET_BE_U_4(esp->esp_seq));
        ND_PRINT(", length %u", length);
 
 #ifdef HAVE_LIBCRYPTO
+       /* 'ep' points to the end of available data. */
+       ep = ndo->ndo_snapend;
+
        /* initialize SAs */
        if (ndo->ndo_sa_list_head == NULL) {
                if (!ndo->ndo_espsecret)