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Diffstat (limited to 'libtomcrypt/src/encauth/ccm/ccm_memory.c')
-rw-r--r--libtomcrypt/src/encauth/ccm/ccm_memory.c112
1 files changed, 77 insertions, 35 deletions
diff --git a/libtomcrypt/src/encauth/ccm/ccm_memory.c b/libtomcrypt/src/encauth/ccm/ccm_memory.c
index 48dc4b7..c5eee18 100644
--- a/libtomcrypt/src/encauth/ccm/ccm_memory.c
+++ b/libtomcrypt/src/encauth/ccm/ccm_memory.c
@@ -6,7 +6,7 @@
* The library is free for all purposes without any express
* guarantee it works.
*
- * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
*/
#include "tomcrypt.h"
@@ -22,6 +22,7 @@
@param cipher The index of the cipher desired
@param key The secret key to use
@param keylen The length of the secret key (octets)
+ @param uskey A previously scheduled key [optional can be NULL]
@param nonce The session nonce [use once]
@param noncelen The length of the nonce
@param header The header for the session
@@ -36,6 +37,7 @@
*/
int ccm_memory(int cipher,
const unsigned char *key, unsigned long keylen,
+ symmetric_key *uskey,
const unsigned char *nonce, unsigned long noncelen,
const unsigned char *header, unsigned long headerlen,
unsigned char *pt, unsigned long ptlen,
@@ -48,7 +50,9 @@ int ccm_memory(int cipher,
int err;
unsigned long len, L, x, y, z, CTRlen;
- LTC_ARGCHK(key != NULL);
+ if (uskey == NULL) {
+ LTC_ARGCHK(key != NULL);
+ }
LTC_ARGCHK(nonce != NULL);
if (headerlen > 0) {
LTC_ARGCHK(header != NULL);
@@ -85,15 +89,15 @@ int ccm_memory(int cipher,
/* is there an accelerator? */
if (cipher_descriptor[cipher].accel_ccm_memory != NULL) {
- cipher_descriptor[cipher].accel_ccm_memory(
+ return cipher_descriptor[cipher].accel_ccm_memory(
key, keylen,
+ uskey,
nonce, noncelen,
header, headerlen,
pt, ptlen,
ct,
tag, taglen,
direction);
- return CRYPT_OK;
}
/* let's get the L value */
@@ -113,23 +117,32 @@ int ccm_memory(int cipher,
L = 15 - noncelen;
}
- /* allocate mem for the symmetric key */
- skey = XMALLOC(sizeof(*skey));
- if (skey == NULL) {
- return CRYPT_MEM;
+ /* decrease noncelen to match L */
+ if ((noncelen + L) > 15) {
+ noncelen = 15 - L;
}
- /* initialize the cipher */
- if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, skey)) != CRYPT_OK) {
- XFREE(skey);
- return err;
+ /* allocate mem for the symmetric key */
+ if (uskey == NULL) {
+ skey = XMALLOC(sizeof(*skey));
+ if (skey == NULL) {
+ return CRYPT_MEM;
+ }
+
+ /* initialize the cipher */
+ if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, skey)) != CRYPT_OK) {
+ XFREE(skey);
+ return err;
+ }
+ } else {
+ skey = uskey;
}
/* form B_0 == flags | Nonce N | l(m) */
x = 0;
- PAD[x++] = ((headerlen > 0) ? (1<<6) : 0) |
+ PAD[x++] = (unsigned char)(((headerlen > 0) ? (1<<6) : 0) |
(((*taglen - 2)>>1)<<3) |
- (L-1);
+ (L-1));
/* nonce */
for (y = 0; y < (16 - (L + 1)); y++) {
@@ -149,12 +162,14 @@ int ccm_memory(int cipher,
PAD[x++] = 0;
}
for (; y < L; y++) {
- PAD[x++] = (len >> 24) & 255;
+ PAD[x++] = (unsigned char)((len >> 24) & 255);
len <<= 8;
}
/* encrypt PAD */
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
/* handle header */
if (headerlen > 0) {
@@ -177,7 +192,9 @@ int ccm_memory(int cipher,
for (y = 0; y < headerlen; y++) {
if (x == 16) {
/* full block so let's encrypt it */
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
x = 0;
}
PAD[x++] ^= header[y];
@@ -185,7 +202,9 @@ int ccm_memory(int cipher,
/* remainder? */
if (x != 0) {
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
}
}
@@ -193,7 +212,7 @@ int ccm_memory(int cipher,
x = 0;
/* flags */
- ctr[x++] = L-1;
+ ctr[x++] = (unsigned char)L-1;
/* nonce */
for (y = 0; y < (16 - (L+1)); ++y) {
@@ -219,14 +238,18 @@ int ccm_memory(int cipher,
ctr[z] = (ctr[z] + 1) & 255;
if (ctr[z]) break;
}
- cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
/* xor the PT against the pad first */
for (z = 0; z < 16; z += sizeof(LTC_FAST_TYPE)) {
*((LTC_FAST_TYPE*)(&PAD[z])) ^= *((LTC_FAST_TYPE*)(&pt[y+z]));
*((LTC_FAST_TYPE*)(&ct[y+z])) = *((LTC_FAST_TYPE*)(&pt[y+z])) ^ *((LTC_FAST_TYPE*)(&CTRPAD[z]));
}
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
}
} else {
for (; y < (ptlen & ~15); y += 16) {
@@ -235,14 +258,18 @@ int ccm_memory(int cipher,
ctr[z] = (ctr[z] + 1) & 255;
if (ctr[z]) break;
}
- cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
/* xor the PT against the pad last */
for (z = 0; z < 16; z += sizeof(LTC_FAST_TYPE)) {
*((LTC_FAST_TYPE*)(&pt[y+z])) = *((LTC_FAST_TYPE*)(&ct[y+z])) ^ *((LTC_FAST_TYPE*)(&CTRPAD[z]));
*((LTC_FAST_TYPE*)(&PAD[z])) ^= *((LTC_FAST_TYPE*)(&pt[y+z]));
}
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
}
}
}
@@ -255,7 +282,9 @@ int ccm_memory(int cipher,
ctr[z] = (ctr[z] + 1) & 255;
if (ctr[z]) break;
}
- cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
CTRlen = 0;
}
@@ -269,21 +298,32 @@ int ccm_memory(int cipher,
}
if (x == 16) {
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
x = 0;
}
PAD[x++] ^= b;
}
if (x != 0) {
- cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey);
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(PAD, PAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
}
}
- /* setup CTR for the TAG */
- ctr[14] = ctr[15] = 0x00;
- cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey);
- cipher_descriptor[cipher].done(skey);
+ /* setup CTR for the TAG (zero the count) */
+ for (y = 15; y > 15 - L; y--) {
+ ctr[y] = 0x00;
+ }
+ if ((err = cipher_descriptor[cipher].ecb_encrypt(ctr, CTRPAD, skey)) != CRYPT_OK) {
+ goto error;
+ }
+
+ if (skey != uskey) {
+ cipher_descriptor[cipher].done(skey);
+ }
/* store the TAG */
for (x = 0; x < 16 && x < *taglen; x++) {
@@ -296,14 +336,16 @@ int ccm_memory(int cipher,
zeromem(PAD, sizeof(PAD));
zeromem(CTRPAD, sizeof(CTRPAD));
#endif
+error:
+ if (skey != uskey) {
+ XFREE(skey);
+ }
- XFREE(skey);
-
- return CRYPT_OK;
+ return err;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ccm/ccm_memory.c,v $ */
-/* $Revision: 1.9 $ */
-/* $Date: 2005/05/05 14:35:58 $ */
+/* $Revision: 1.18 $ */
+/* $Date: 2006/12/04 21:34:03 $ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 11:24:32 +0000