}
#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
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;
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);
- 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 */
- 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. */
- EVP_Cipher(ctx, output_buffer, p + ivlen, len);
+ set_cipher_parameters(ctx, NULL, NULL, p, 0);
+ 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.
+ */
+ 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 -1;
+ }
+
+ EVP_Cipher(ctx, output_buffer, p + ivlen, len);
EVP_CIPHER_CTX_free(ctx);
- memcpy(p + ivlen, 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(p + ivlen, output_buffer, len);
+ free(output_buffer);
advance = ivoff - (const u_char *)esp + ivlen;
} else
advance = sizeof(struct newesp);
projects / tcpdump / blobdiff