Ensure padding is initialized on return from krb5_c_encrypt_iov()

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/mskrb-integ-crypto-iov@21239 dc483132-0cff-0310-8789-dd5450dbe970

2 files changed, 29 insertions, 5 deletions

diff --git a/src/lib/crypto/arcfour/arcfour_aead.c b/src/lib/crypto/arcfour/arcfour_aead.c
index e9398f4..b506c49 100644
--- a/src/lib/crypto/arcfour/arcfour_aead.c
+++ b/src/lib/crypto/arcfour/arcfour_aead.c
@@ -96,6 +96,7 @@ krb5int_arcfour_encrypt_iov(const struct krb5_aead_provider *aead,
     krb5_keyusage ms_usage;
     char salt_data[14];
     krb5_data salt;
+    size_t i;
 
     d1.length = d2.length = d3.length = 0;
     d1.data = d2.data = d3.data = NULL;
@@ -117,6 +118,12 @@ krb5int_arcfour_encrypt_iov(const struct krb5_aead_provider *aead,
     if (trailer != NULL)
 	trailer->data.length = 0;
 
+    /* Ensure that there is no padding */
+    for (i = 0; i < num_data; i++) {
+	if (data[i].flags == KRB5_CRYPTO_TYPE_PADDING)
+	    data[i].data.length = 0;
+    }
+
     ret = alloc_derived_key(enc, &k1, &d1, key);
     if (ret != 0)
 	goto cleanup;
diff --git a/src/lib/crypto/dk/dk_aead.c b/src/lib/crypto/dk/dk_aead.c
index 746b8c7..ba21d47 100644
--- a/src/lib/crypto/dk/dk_aead.c
+++ b/src/lib/crypto/dk/dk_aead.c
@@ -73,7 +73,7 @@ krb5int_dk_encrypt_iov(const struct krb5_aead_provider *aead,
     krb5_crypto_iov *header, *trailer;
     krb5_keyblock ke, ki;
     size_t i;
-    size_t blocksize = 0; /* careful, this is enc block size not confounder len */
+    size_t blocksize = 0;
     size_t plainlen = 0;
     size_t hmacsize = 0;
     unsigned char *cksum = NULL;
@@ -92,10 +92,27 @@ krb5int_dk_encrypt_iov(const struct krb5_aead_provider *aead,
 	return ret;
 
     for (i = 0; i < num_data; i++) {
-	const krb5_crypto_iov *iov = &data[i];
+	krb5_crypto_iov *iov = &data[i];
 
-	if (ENCRYPT_DATA_IOV(iov))
-	    plainlen += iov->data.length;
+	if (!ENCRYPT_DATA_IOV(iov)) /* DATA | PADDING */
+	    continue;
+
+	if (iov->flags == KRB5_CRYPTO_TYPE_PADDING && i > 0) {
+	    const krb5_crypto_iov *data_to_pad = &data[i - 1];
+	    size_t padlen = 0;
+
+	    if (blocksize != 0) {
+		padlen = blocksize - (data_to_pad->data.length % blocksize);
+
+		if (iov->data.length < padlen)
+		    return KRB5_BAD_MSIZE;
+	    }
+
+	    memset(iov->data.data, 0, padlen);
+	    iov->data.length = padlen;
+	}
+
+	plainlen += iov->data.length;
     }
 
     if (blocksize == 0) {
@@ -250,7 +267,7 @@ krb5int_dk_decrypt_iov(const struct krb5_aead_provider *aead,
 	    return KRB5_BAD_MSIZE;
     } else {
 	/* Check that the input data is correctly padded */
-	if (cipherlen % blocksize != 0)
+	if ((cipherlen % blocksize) != 0)
 	    return KRB5_BAD_MSIZE;
     }