}
#endif
+#ifdef HAVE_EVP_CIPHERINIT_EX
+/*
+ * Initialize the cipher by calling EVP_CipherInit_ex(), because
+ * calling EVP_CipherInit() will reset the cipher context, clearing
+ * the cipher, so calling it twice, with the second call having a
+ * null cipher, will clear the already-set cipher. EVP_CipherInit_ex(),
+ * however, won't reset the cipher context, so you can use it to specify
+ * the IV oin a second call after a first call to EVP_CipherInit_ex()
+ * to set the cipher and the key.
+ *
+ * XXX - is there some reason why we need to make two calls?
+ */
+static int
+set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
+ const unsigned char *key,
+ const unsigned char *iv, int enc)
+{
+ return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
+}
+#else
+/*
+ * Initialize the cipher by calling EVP_CipherInit(), because we don't
+ * have EVP_CipherInit_ex(); we rely on it not trashing the context.
+ */
+static int
+set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
+ const unsigned char *key,
+ const unsigned char *iv, int enc)
+{
+ return EVP_CipherInit(ctx, cipher, key, iv, enc);
+}
+#endif
+
/*
* this will adjust ndo_packetp and ndo_snapend to new buffer!
*/
{
struct sa_list *sa;
const u_char *iv;
- u_char *buf_mut, *output_buffer;
- int len, block_size, cipher_nid, output_buffer_size ;
+ unsigned int len;
EVP_CIPHER_CTX *ctx;
+ unsigned int block_size, output_buffer_size;
+ u_char *output_buffer;
/* initiator arg is any non-zero value */
if(initiator) initiator=1;
ctx = EVP_CIPHER_CTX_new();
if (ctx == NULL)
return 0;
- if (EVP_CipherInit(ctx, sa->evp, sa->secret, NULL, 0) < 0)
+ if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL, 0) < 0)
(*ndo->ndo_warning)(ndo, "espkey init failed");
- EVP_CipherInit(ctx, NULL, NULL, iv, 0);
-
- /* We need a block size */
- block_size = EVP_CIPHER_CTX_block_size(ctx);
- /* We need the buffer size to be multiple of a block size */
- output_buffer_size = len + (block_size - len % block_size);
- output_buffer = (u_char *)calloc(output_buffer_size, sizeof(u_char));
- /* EVP_Cipher output buffer should be different from the input one.
- * Also it should be of size that is multiple of cipher block size. */
+ 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.
+ */
+ 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);
+ if (output_buffer == NULL) {
+ (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer");
+ EVP_CIPHER_CTX_free(ctx);
+ return 0;
+ }
EVP_Cipher(ctx, output_buffer, buf, len);
EVP_CIPHER_CTX_free(ctx);
- buf_mut = (u_char*) buf;
- /* Of course this is wrong, because buf is a const buffer, but changing this
- * would require more complicated fix. */
- memcpy(buf_mut, output_buffer, len);
- free(output_buffer);
+ /*
+ * XXX - of course this is wrong, because buf is a const buffer,
+ * but changing this would require a more complicated fix.
+ */
+ memcpy(buf, output_buffer, len);
+ free(output_buffer);
ndo->ndo_packetp = buf;
ndo->ndo_snapend = end;
return 1;
-
-
}
USES_APPLE_RST
_U_
#endif
,
- int *nhdr
+ u_int *nhdr
#ifndef HAVE_LIBCRYPTO
_U_
#endif
,
- int *padlen
+ u_int *padlen
#ifndef HAVE_LIBCRYPTO
_U_
#endif
)
{
- register const struct newesp *esp;
- register const u_char *ep;
+ const struct newesp *esp;
+ const u_char *ep;
#ifdef HAVE_LIBCRYPTO
const struct ip *ip;
struct sa_list *sa = NULL;
const u_char *ivoff;
const u_char *p;
EVP_CIPHER_CTX *ctx;
- u_char *buf_mut, *output_buffer;
- int block_size, cipher_nid, output_buffer_size;
+ unsigned int block_size, output_buffer_size;
+ u_char *output_buffer;
#endif
esp = (const struct newesp *)bp;
ND_PRINT((ndo, "[|ESP]"));
goto fail;
}
- ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi)));
- ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq)));
+ 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));
#ifndef HAVE_LIBCRYPTO
case 6:
ip6 = (const struct ip6_hdr *)bp2;
/* we do not attempt to decrypt jumbograms */
- if (!EXTRACT_16BITS(&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_16BITS(&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_32BITS(&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) {
break;
case 4:
/* nexthdr & padding are in the last fragment */
- if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
+ if (EXTRACT_BE_U_2(&ip->ip_off) & IP_MF)
goto fail;
- len = EXTRACT_16BITS(&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_32BITS(&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) {
ep = bp2 + len;
}
+ /* pointer to the IV, if there is one */
ivoff = (const u_char *)(esp + 1) + 0;
+ /* length of the IV, if there is one; 0, if there isn't */
ivlen = sa->ivlen;
secret = sa->secret;
ep = ep - sa->authlen;
if (sa->evp) {
ctx = EVP_CIPHER_CTX_new();
if (ctx != NULL) {
- if (EVP_CipherInit(ctx, sa->evp, secret, NULL, 0) < 0)
+ if (set_cipher_parameters(ctx, sa->evp, secret, NULL, 0) < 0)
(*ndo->ndo_warning)(ndo, "espkey init failed");
p = ivoff;
- EVP_CipherInit(ctx, NULL, NULL, p, 0);
+ set_cipher_parameters(ctx, NULL, NULL, p, 0);
len = ep - (p + ivlen);
- /* We need a block size */
- block_size = EVP_CIPHER_CTX_block_size(ctx);
- /* We need the buffer size to be multiple of a block size */
+ /*
+ * 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.
+ */
+ block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
output_buffer_size = len + (block_size - len % block_size);
- output_buffer = (u_char *)calloc(output_buffer_size, sizeof(u_char));
- /* EVP_Cipher output buffer should be different from the input one.
- * Also it should be of size that is multiple of cipher block size. */
+ output_buffer = (u_char *)malloc(output_buffer_size);
+ if (output_buffer == NULL) {
+ (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer");
+ EVP_CIPHER_CTX_free(ctx);
+ return -1;
+ }
+
EVP_Cipher(ctx, output_buffer, p + ivlen, len);
EVP_CIPHER_CTX_free(ctx);
+ /*
+ * XXX - of course this is wrong, because buf is a
+ * const buffer, but changing this would require a
+ * more complicated fix.
+ */
memcpy(p + ivlen, output_buffer, len);
free(output_buffer);
advance = ivoff - (const u_char *)esp + ivlen;
advance = sizeof(struct newesp);
/* sanity check for pad length */
- if (ep - bp < *(ep - 2))
+ if (ep - bp < EXTRACT_U_1(ep - 2))
goto fail;
if (padlen)
- *padlen = *(ep - 2) + 2;
+ *padlen = EXTRACT_U_1(ep - 2) + 2;
if (nhdr)
- *nhdr = *(ep - 1);
+ *nhdr = EXTRACT_U_1(ep - 1);
ND_PRINT((ndo, ": "));
return advance;
projects / tcpdump / blobdiff