]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-esp.c
Merge pull request #703 from nmap/update-gitignore
[tcpdump] / print-esp.c
index 646320abc3a641c237a0d3216e7f134638968663..e5a490f552fb416a50e316ecd19bc42ec5b407d5 100644 (file)
 /* \summary: IPSEC Encapsulating Security Payload (ESP) printer */
 
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#include <netdissect-stdinc.h>
+#include "netdissect-stdinc.h"
 
 #include <string.h>
 #include <stdlib.h>
@@ -87,8 +87,8 @@
  */
 
 struct newesp {
-       uint32_t        esp_spi;        /* ESP */
-       uint32_t        esp_seq;        /* Sequence number */
+       nd_uint32_t     esp_spi;        /* ESP */
+       nd_uint32_t     esp_seq;        /* Sequence number */
        /*variable size*/               /* (IV and) Payload data */
        /*variable size*/               /* padding */
        /*8bit*/                        /* pad size */
@@ -192,8 +192,8 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
        const u_char *iv;
        unsigned int len;
        EVP_CIPHER_CTX *ctx;
-       unsigned int block_size, output_buffer_size;
-       u_char *output_buffer;
+       unsigned int block_size, buffer_size;
+       u_char *input_buffer, *output_buffer;
 
        /* initiator arg is any non-zero value */
        if(initiator) initiator=1;
@@ -228,19 +228,41 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
                (*ndo->ndo_warning)(ndo, "espkey init failed");
        set_cipher_parameters(ctx, NULL, NULL, iv, 0);
        /*
-        * Allocate a buffer for the decrypted data.
-        * The output buffer must be separate from the input buffer, and
-        * its size must be a multiple of the cipher block size.
+        * Allocate buffers for the encrypted and decrypted data.
+        * Both buffers' sizes must be a multiple of the cipher block
+        * size, and the output buffer must be separate from the input
+        * buffer.
         */
        block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
-       output_buffer_size = len + (block_size - len % block_size);
-       output_buffer = (u_char *)malloc(output_buffer_size);
+       buffer_size = len + (block_size - len % block_size);
+
+       /*
+        * Attempt to allocate the input buffer.
+        */
+       input_buffer = (u_char *)malloc(buffer_size);
+       if (input_buffer == NULL) {
+               EVP_CIPHER_CTX_free(ctx);
+               (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+                       "can't allocate memory for encrypted data buffer");
+       }
+       /*
+        * Copy the input data to the encrypted data buffer, and pad it
+        * with zeroes.
+        */
+       memcpy(input_buffer, buf, len);
+       memset(input_buffer + len, 0, buffer_size - len);
+
+       /*
+        * Attempt to allocate the output buffer.
+        */
+       output_buffer = (u_char *)malloc(buffer_size);
        if (output_buffer == NULL) {
-               (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer");
+               free(input_buffer);
                EVP_CIPHER_CTX_free(ctx);
-               return 0;
+               (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+                       "can't allocate memory for decryption buffer");
        }
-       EVP_Cipher(ctx, output_buffer, buf, len);
+       EVP_Cipher(ctx, output_buffer, input_buffer, len);
        EVP_CIPHER_CTX_free(ctx);
 
        /*
@@ -248,6 +270,7 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
         * but changing this would require a more complicated fix.
         */
        memcpy(buf, output_buffer, len);
+       free(input_buffer);
        free(output_buffer);
 
        ndo->ndo_packetp = buf;
@@ -264,9 +287,11 @@ static void esp_print_addsa(netdissect_options *ndo,
 
        struct sa_list *nsa;
 
+       /* malloc() return used in a 'struct sa_list': do not free() */
        nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
        if (nsa == NULL)
-               (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure");
+               (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+                                 "esp_print_addsa: malloc");
 
        *nsa = *sa;
 
@@ -287,8 +312,8 @@ static u_int hexdigit(netdissect_options *ndo, char hex)
        else if (hex >= 'a' && hex <= 'f')
                return (hex - 'a' + 10);
        else {
-               (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex);
-               return 0;
+               (*ndo->ndo_error)(ndo, S_ERR_ND_ESP_SECRET,
+                                 "invalid hex digit %c in espsecret\n", hex);
        }
 }
 
@@ -314,7 +339,7 @@ int espprint_decode_hex(netdissect_options *ndo,
        len = strlen(hex) / 2;
 
        if (len > binbuf_len) {
-               (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len);
+               (*ndo->ndo_warning)(ndo, "secret is too big: %u\n", len);
                return 0;
        }
 
@@ -399,7 +424,7 @@ espprint_decode_encalgo(netdissect_options *ndo,
 USES_APPLE_RST
 
 /*
- * for the moment, ignore the auth algorith, just hard code the authenticator
+ * for the moment, ignore the auth algorithm, just hard code the authenticator
  * length. Need to research how openssl looks up HMAC stuff.
  */
 static int
@@ -520,9 +545,9 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
 
                secretfile = fopen(filename, FOPEN_READ_TXT);
                if (secretfile == NULL) {
-                       (*ndo->ndo_error)(ndo, "print_esp: can't open %s: %s\n",
-                           filename, strerror(errno));
-                       return;
+                       (*ndo->ndo_error)(ndo, S_ERR_ND_OPEN_FILE,
+                                         "print_esp: can't open %s: %s\n",
+                                         filename, strerror(errno));
                }
 
                while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
@@ -552,6 +577,10 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
                uint32_t spino;
 
                spistr = strsep(&spikey, "@");
+               if (spistr == NULL) {
+                       (*ndo->ndo_warning)(ndo, "print_esp: failed to find the @ token");
+                       return;
+               }
 
                spino = strtoul(spistr, &foo, 0);
                if (spistr == foo || !spikey) {
@@ -661,10 +690,11 @@ esp_print(netdissect_options *ndo,
        const u_char *ivoff;
        const u_char *p;
        EVP_CIPHER_CTX *ctx;
-       unsigned int block_size, output_buffer_size;
-       u_char *output_buffer;
+       unsigned int block_size, buffer_size;
+       u_char *input_buffer, *output_buffer;
 #endif
 
+       ndo->ndo_protocol = "esp";
        esp = (const struct newesp *)bp;
 
 #ifdef HAVE_LIBCRYPTO
@@ -681,12 +711,12 @@ esp_print(netdissect_options *ndo,
        ep = ndo->ndo_snapend;
 
        if ((const u_char *)(esp + 1) >= ep) {
-               ND_PRINT((ndo, "[|ESP]"));
+               nd_print_trunc(ndo);
                goto fail;
        }
-       ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_BE_U_4(&esp->esp_spi)));
-       ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_BE_U_4(&esp->esp_seq)));
-       ND_PRINT((ndo, ", length %u", length));
+       ND_PRINT("ESP(spi=0x%08x", EXTRACT_BE_U_4(esp->esp_spi));
+       ND_PRINT(",seq=0x%x)", EXTRACT_BE_U_4(esp->esp_seq));
+       ND_PRINT(", length %u", length);
 
 #ifndef HAVE_LIBCRYPTO
        goto fail;
@@ -707,33 +737,33 @@ esp_print(netdissect_options *ndo,
        case 6:
                ip6 = (const struct ip6_hdr *)bp2;
                /* we do not attempt to decrypt jumbograms */
-               if (!EXTRACT_BE_U_2(&ip6->ip6_plen))
+               if (!EXTRACT_BE_U_2(ip6->ip6_plen))
                        goto fail;
                /* if we can't get nexthdr, we do not need to decrypt it */
-               len = sizeof(struct ip6_hdr) + EXTRACT_BE_U_2(&ip6->ip6_plen);
+               len = sizeof(struct ip6_hdr) + EXTRACT_BE_U_2(ip6->ip6_plen);
 
                /* see if we can find the SA, and if so, decode it */
                for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
-                       if (sa->spi == EXTRACT_BE_U_4(&esp->esp_spi) &&
+                       if (sa->spi == EXTRACT_BE_U_4(esp->esp_spi) &&
                            sa->daddr_version == 6 &&
                            UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst,
-                                  sizeof(struct in6_addr)) == 0) {
+                                  sizeof(nd_ipv6)) == 0) {
                                break;
                        }
                }
                break;
        case 4:
                /* nexthdr & padding are in the last fragment */
-               if (EXTRACT_BE_U_2(&ip->ip_off) & IP_MF)
+               if (EXTRACT_BE_U_2(ip->ip_off) & IP_MF)
                        goto fail;
-               len = EXTRACT_BE_U_2(&ip->ip_len);
+               len = EXTRACT_BE_U_2(ip->ip_len);
 
                /* see if we can find the SA, and if so, decode it */
                for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
-                       if (sa->spi == EXTRACT_BE_U_4(&esp->esp_spi) &&
+                       if (sa->spi == EXTRACT_BE_U_4(esp->esp_spi) &&
                            sa->daddr_version == 4 &&
                            UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst,
-                                  sizeof(struct in_addr)) == 0) {
+                                  sizeof(nd_ipv4)) == 0) {
                                break;
                        }
                }
@@ -778,21 +808,43 @@ esp_print(netdissect_options *ndo,
                        len = ep - (p + ivlen);
 
                        /*
-                        * Allocate a buffer for the decrypted data.
-                        * The output buffer must be separate from the
-                        * input buffer, and its size must be a multiple
-                        * of the cipher block size.
+                        * Allocate buffers for the encrypted and decrypted
+                        * data.  Both buffers' sizes must be a multiple of
+                        * the cipher block size, and the output buffer must
+                        * be separate from the input buffer.
                         */
                        block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
-                       output_buffer_size = len + (block_size - len % block_size);
-                       output_buffer = (u_char *)malloc(output_buffer_size);
+                       buffer_size = len + (block_size - len % block_size);
+
+                       /*
+                        * Attempt to allocate the input buffer.
+                        */
+                       input_buffer = (u_char *)malloc(buffer_size);
+                       if (input_buffer == NULL) {
+                               EVP_CIPHER_CTX_free(ctx);
+                               (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+                                       "esp_print: can't allocate memory for encrypted data buffer");
+                       }
+                       /*
+                        * Copy the input data to the encrypted data buffer,
+                        * and pad it with zeroes.
+                        */
+                       memcpy(input_buffer, p + ivlen, len);
+                       memset(input_buffer + len, 0, buffer_size - len);
+
+                       /*
+                        * Attempt to allocate the output buffer.
+                        */
+                       output_buffer = (u_char *)malloc(buffer_size);
                        if (output_buffer == NULL) {
-                               (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer");
+                               free(input_buffer);
                                EVP_CIPHER_CTX_free(ctx);
-                               return -1;
+                               (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+                                       "esp_print: can't allocate memory for decryption buffer");
                        }
 
-                       EVP_Cipher(ctx, output_buffer, p + ivlen, len);
+                       EVP_Cipher(ctx, output_buffer, input_buffer, len);
+                       free(input_buffer);
                        EVP_CIPHER_CTX_free(ctx);
                        /*
                         * XXX - of course this is wrong, because buf is a
@@ -817,7 +869,7 @@ esp_print(netdissect_options *ndo,
        if (nhdr)
                *nhdr = EXTRACT_U_1(ep - 1);
 
-       ND_PRINT((ndo, ": "));
+       ND_PRINT(": ");
        return advance;
 #endif
 
@@ -827,10 +879,3 @@ fail:
 #ifdef HAVE_LIBCRYPTO
 USES_APPLE_RST
 #endif
-
-/*
- * Local Variables:
- * c-style: whitesmith
- * c-basic-offset: 8
- * End:
- */