mozilla-nss/nss-fips-gcm-ctr.patch

63 lines
2.1 KiB
Diff

# HG changeset patch
# User Hans Petter Jansson <hpj@cl.no>
# Date 1574234739 -3600
# Wed Nov 20 08:25:39 2019 +0100
# Node ID 5396ffb26887cc0cd42b9f12cc6c8e3dfdaf194b
# Parent f5cf5d16deb68e65b5dd4e799d9e8e3098400d62
[PATCH] 22
From 41dd171b242b0cb550d12760da110db7e2c21daf Mon Sep 17 00:00:00 2001
---
nss/lib/freebl/gcm.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
Index: nss/lib/freebl/gcm.c
===================================================================
--- nss.orig/lib/freebl/gcm.c
+++ nss/lib/freebl/gcm.c
@@ -535,8 +535,14 @@ struct GCMContextStr {
unsigned char tagKey[MAX_BLOCK_SIZE];
PRBool ctr_context_init;
gcmIVContext gcm_iv;
+ unsigned long long gcm_iv_bytes;
};
+/* NIST SP-800-38D limits the use of GCM with a single IV to 2^39 - 256
+ * bits which translates to 2^32 - 2 128bit blocks or 2^36 - 32 bytes
+ */
+#define MAX_GCM_BYTES_PER_IV ((1ULL << 36) - 32)
+
SECStatus gcm_InitCounter(GCMContext *gcm, const unsigned char *iv,
unsigned int ivLen, unsigned int tagBits,
const unsigned char *aad, unsigned int aadLen);
@@ -676,6 +682,8 @@ gcm_InitCounter(GCMContext *gcm, const u
goto loser;
}
+ gcm->gcm_iv_bytes = MAX_GCM_BYTES_PER_IV;
+
/* finally mix in the AAD data */
rv = gcmHash_Reset(ghash, aad, aadLen);
if (rv != SECSuccess) {
@@ -777,6 +785,13 @@ GCM_EncryptUpdate(GCMContext *gcm, unsig
return SECFailure;
}
+ /* bail out if this invocation requests processing more than what is
+ * considered to be a safe limit */
+ if (gcm->gcm_iv_bytes < (unsigned long long)inlen) {
+ PORT_SetError(SEC_ERROR_INPUT_LEN);
+ return SECFailure;
+ }
+
tagBytes = (gcm->tagBits + (PR_BITS_PER_BYTE - 1)) / PR_BITS_PER_BYTE;
if (UINT_MAX - inlen < tagBytes) {
PORT_SetError(SEC_ERROR_INPUT_LEN);
@@ -805,6 +820,7 @@ GCM_EncryptUpdate(GCMContext *gcm, unsig
*outlen = 0;
return SECFailure;
};
+ gcm->gcm_iv_bytes -= inlen;
*outlen += len;
return SECSuccess;
}