trustbridge/nss-cmake-static: nss/lib/freebl/cts.c annotate

annotate nss/lib/freebl/cts.c @ 0:1e5118fa0cb1

This is NSS with a Cmake Buildsyste To compile a static NSS library for Windows we've used the Chromium-NSS fork and added a Cmake buildsystem to compile it statically for Windows. See README.chromium for chromium changes and README.trustbridge for our modifications.

author	Andre Heinecke <andre.heinecke@intevation.de>
date	Mon, 28 Jul 2014 10:47:06 +0200
parents
children

rev	line source
0 1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	1 /* This Source Code Form is subject to the terms of the Mozilla Public
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	2 * License, v. 2.0. If a copy of the MPL was not distributed with this
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	4
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	5 #ifdef FREEBL_NO_DEPEND
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	6 #include "stubs.h"
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	7 #endif
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	8 #include "blapit.h"
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	9 #include "blapii.h"
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	10 #include "cts.h"
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	11 #include "secerr.h"
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	12
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	13 struct CTSContextStr {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	14 freeblCipherFunc cipher;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	15 void *context;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	16 /* iv stores the last ciphertext block of the previous message.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	17 * Only used by decrypt. */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	18 unsigned char iv[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	19 };
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	20
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	21 CTSContext *
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	22 CTS_CreateContext(void *context, freeblCipherFunc cipher,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	23 const unsigned char *iv, unsigned int blocksize)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	24 {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	25 CTSContext *cts;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	26
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	27 if (blocksize > MAX_BLOCK_SIZE) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	28 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	29 return NULL;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	30 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	31 cts = PORT_ZNew(CTSContext);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	32 if (cts == NULL) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	33 return NULL;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	34 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	35 PORT_Memcpy(cts->iv, iv, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	36 cts->cipher = cipher;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	37 cts->context = context;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	38 return cts;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	39 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	40
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	41 void
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	42 CTS_DestroyContext(CTSContext *cts, PRBool freeit)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	43 {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	44 if (freeit) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	45 PORT_Free(cts);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	46 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	47 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	48
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	49 /*
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	50 * See addemdum to NIST SP 800-38A
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	51 * Generically handle cipher text stealing. Basically this is doing CBC
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	52 * operations except someone can pass us a partial block.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	53 *
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	54 * Output Order:
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	55 * CS-1: C1\|\|C2\|\|C3..Cn-1(could be partial)\|\|Cn (NIST)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	56 * CS-2: pad == 0 C1\|\|C2\|\|C3...Cn-1(is full)\|\|Cn (Schneier)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	57 * CS-2: pad != 0 C1\|\|C2\|\|C3...Cn\|\|Cn-1(is partial)(Schneier)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	58 * CS-3: C1\|\|C2\|\|C3...Cn\|\|Cn-1(could be partial) (Kerberos)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	59 *
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	60 * The characteristics of these three options:
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	61 * - NIST & Schneier (CS-1 & CS-2) are identical to CBC if there are no
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	62 * partial blocks on input.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	63 * - Scheier and Kerberos (CS-2 and CS-3) have no embedded partial blocks,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	64 * which make decoding easier.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	65 * - NIST & Kerberos (CS-1 and CS-3) have consistent block order independent
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	66 * of padding.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	67 *
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	68 * PKCS #11 did not specify which version to implement, but points to the NIST
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	69 * spec, so this code implements CTS-CS-1 from NIST.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	70 *
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	71 * To convert the returned buffer to:
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	72 * CS-2 (Schneier): do
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	73 * unsigned char tmp[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	74 * pad = *outlen % blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	75 * if (pad) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	76 * memcpy(tmp, outbuf+*outlen-blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	77 * memcpy(outbuf+outlen-pad,outbuf+outlen-blocksize-pad, pad);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	78 * memcpy(outbuf+*outlen-blocksize-pad, tmp, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	79 * }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	80 * CS-3 (Kerberos): do
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	81 * unsigned char tmp[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	82 * pad = *outlen % blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	83 * if (pad == 0) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	84 * pad = blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	85 * }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	86 * memcpy(tmp, outbuf+*outlen-blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	87 * memcpy(outbuf+outlen-pad,outbuf+outlen-blocksize-pad, pad);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	88 * memcpy(outbuf+*outlen-blocksize-pad, tmp, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	89 */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	90 SECStatus
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	91 CTS_EncryptUpdate(CTSContext cts, unsigned char outbuf,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	92 unsigned int *outlen, unsigned int maxout,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	93 const unsigned char *inbuf, unsigned int inlen,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	94 unsigned int blocksize)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	95 {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	96 unsigned char lastBlock[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	97 unsigned int tmp;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	98 int fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	99 int written;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	100 SECStatus rv;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	101
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	102 if (inlen < blocksize) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	103 PORT_SetError(SEC_ERROR_INPUT_LEN);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	104 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	105 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	106
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	107 if (maxout < inlen) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	108 *outlen = inlen;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	109 PORT_SetError(SEC_ERROR_OUTPUT_LEN);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	110 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	111 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	112 fullblocks = (inlen/blocksize)*blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	113 rv = (*cts->cipher)(cts->context, outbuf, outlen, maxout, inbuf,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	114 fullblocks, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	115 if (rv != SECSuccess) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	116 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	117 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	118 outlen = fullblocks; / AES low level doesn't set outlen */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	119 inbuf += fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	120 inlen -= fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	121 if (inlen == 0) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	122 return SECSuccess;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	123 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	124 written = *outlen - (blocksize - inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	125 outbuf += written;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	126 maxout -= written;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	127
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	128 /*
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	129 * here's the CTS magic, we pad our final block with zeros,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	130 * then do a CBC encrypt. CBC will xor our plain text with
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	131 * the previous block (Cn-1), capturing part of that block (Cn-1**) as it
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	132 * xors with the zero pad. We then write this full block, overwritting
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	133 * (Cn-1**) in our buffer. This allows us to have input data == output
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	134 * data since Cn contains enough information to reconver Cn-1** when
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	135 * we decrypt (at the cost of some complexity as you can see in decrypt
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	136 * below */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	137 PORT_Memcpy(lastBlock, inbuf, inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	138 PORT_Memset(lastBlock + inlen, 0, blocksize - inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	139 rv = (*cts->cipher)(cts->context, outbuf, &tmp, maxout, lastBlock,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	140 blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	141 PORT_Memset(lastBlock, 0, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	142 if (rv == SECSuccess) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	143 *outlen = written + blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	144 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	145 return rv;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	146 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	147
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	148
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	149 #define XOR_BLOCK(x,y,count) for(i=0; i < count; i++) x[i] = x[i] ^ y[i]
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	150
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	151 /*
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	152 * See addemdum to NIST SP 800-38A
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	153 * Decrypt, Expect CS-1: input. See the comment on the encrypt side
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	154 * to understand what CS-2 and CS-3 mean.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	155 *
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	156 * To convert the input buffer to CS-1 from ...
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	157 * CS-2 (Schneier): do
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	158 * unsigned char tmp[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	159 * pad = inlen % blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	160 * if (pad) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	161 * memcpy(tmp, inbuf+inlen-blocksize-pad, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	162 * memcpy(inbuf+inlen-blocksize-pad,inbuf+inlen-pad, pad);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	163 * memcpy(inbuf+inlen-blocksize, tmp, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	164 * }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	165 * CS-3 (Kerberos): do
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	166 * unsigned char tmp[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	167 * pad = inlen % blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	168 * if (pad == 0) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	169 * pad = blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	170 * }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	171 * memcpy(tmp, inbuf+inlen-blocksize-pad, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	172 * memcpy(inbuf+inlen-blocksize-pad,inbuf+inlen-pad, pad);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	173 * memcpy(inbuf+inlen-blocksize, tmp, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	174 */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	175 SECStatus
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	176 CTS_DecryptUpdate(CTSContext cts, unsigned char outbuf,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	177 unsigned int *outlen, unsigned int maxout,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	178 const unsigned char *inbuf, unsigned int inlen,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	179 unsigned int blocksize)
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	180 {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	181 unsigned char *Pn;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	182 unsigned char Cn_2[MAX_BLOCK_SIZE]; /* block Cn-2 */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	183 unsigned char Cn_1[MAX_BLOCK_SIZE]; /* block Cn-1 */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	184 unsigned char Cn[MAX_BLOCK_SIZE]; /* block Cn */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	185 unsigned char lastBlock[MAX_BLOCK_SIZE];
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	186 const unsigned char *tmp;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	187 unsigned int tmpLen;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	188 int fullblocks, pad;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	189 unsigned int i;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	190 SECStatus rv;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	191
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	192 if (inlen < blocksize) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	193 PORT_SetError(SEC_ERROR_INPUT_LEN);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	194 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	195 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	196
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	197 if (maxout < inlen) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	198 *outlen = inlen;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	199 PORT_SetError(SEC_ERROR_OUTPUT_LEN);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	200 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	201 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	202
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	203 fullblocks = (inlen/blocksize)*blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	204
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	205 /* even though we expect the input to be CS-1, CS-2 is easier to parse,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	206 * so convert to CS-2 immediately. NOTE: this is the same code as in
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	207 * the comment for encrypt. NOTE2: since we can't modify inbuf unless
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	208 * inbuf and outbuf overlap, just copy inbuf to outbuf and modify it there
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	209 */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	210 pad = inlen - fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	211 if (pad != 0) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	212 if (inbuf != outbuf) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	213 memcpy(outbuf, inbuf, inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	214 /* keep the names so we logically know how we are using the
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	215 * buffers */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	216 inbuf = outbuf;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	217 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	218 memcpy(lastBlock, inbuf+inlen-blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	219 /* we know inbuf == outbuf now, inbuf is declared const and can't
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	220 * be the target, so use outbuf for the target here */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	221 memcpy(outbuf+inlen-pad, inbuf+inlen-blocksize-pad, pad);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	222 memcpy(outbuf+inlen-blocksize-pad, lastBlock, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	223 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	224 /* save the previous to last block so we can undo the misordered
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	225 * chaining */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	226 tmp = (fullblocks < blocksize*2) ? cts->iv :
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	227 inbuf+fullblocks-blocksize*2;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	228 PORT_Memcpy(Cn_2, tmp, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	229 PORT_Memcpy(Cn, inbuf+fullblocks-blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	230 rv = (*cts->cipher)(cts->context, outbuf, outlen, maxout, inbuf,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	231 fullblocks, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	232 if (rv != SECSuccess) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	233 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	234 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	235 outlen = fullblocks; / AES low level doesn't set outlen */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	236 inbuf += fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	237 inlen -= fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	238 if (inlen == 0) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	239 return SECSuccess;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	240 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	241 outbuf += fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	242 maxout -= fullblocks;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	243
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	244 /* recover the stolen text */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	245 PORT_Memset(lastBlock, 0, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	246 PORT_Memcpy(lastBlock, inbuf, inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	247 PORT_Memcpy(Cn_1, inbuf, inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	248 Pn = outbuf-blocksize;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	249 /* inbuf points to Cn-1* in the input buffer */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	250 /* NOTE: below there are 2 sections marked "make up for the out of order
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	251 * cbc decryption". You may ask, what is going on here.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	252 * Short answer: CBC automatically xors the plain text with the previous
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	253 * encrypted block. We are decrypting the last 2 blocks out of order, so
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	254 * we have to 'back out' the decrypt xor and 'add back' the encrypt xor.
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	255 * Long answer: When we encrypted, we encrypted as follows:
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	256 * Pn-2, Pn-1, (Pn \|\| 0), but on decryption we can't
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	257 * decrypt Cn-1 until we decrypt Cn because part of Cn-1 is stored in
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	258 * Cn (see below). So above we decrypted all the full blocks:
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	259 * Cn-2, Cn,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	260 * to get:
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	261 * Pn-2, Pn, Except that Pn is not yet corect. On encrypt, we
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	262 * xor'd Pn \|\| 0 with Cn-1, but on decrypt we xor'd it with Cn-2
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	263 * To recover Pn, we xor the block with Cn-1* \|\| 0 (in last block) and
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	264 * Cn-2 to get Pn \|\| Cn-1**. Pn can then be written to the output buffer
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	265 * and we can now reunite Cn-1. With the full Cn-1 we can decrypt it,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	266 * but now decrypt is going to xor the decrypted data with Cn instead of
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	267 * Cn-2. xoring Cn and Cn-2 restores the original Pn-1 and we can now
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	268 * write that oout to the buffer */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	269
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	270 /* make up for the out of order CBC decryption */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	271 XOR_BLOCK(lastBlock, Cn_2, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	272 XOR_BLOCK(lastBlock, Pn, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	273 /* last buf now has Pn \|\| Cn-1*, copy out Pn /
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	274 PORT_Memcpy(outbuf, lastBlock, inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	275 *outlen += inlen;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	276 /* copy Cn-1* into last buf to recover Cn-1 */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	277 PORT_Memcpy(lastBlock, Cn_1, inlen);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	278 /* note: because Cn and Cn-1 were out of order, our pointer to Pn also
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	279 * points to where Pn-1 needs to reside. From here on out read Pn in
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	280 * the code as really Pn-1. */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	281 rv = (*cts->cipher)(cts->context, Pn, &tmpLen, blocksize, lastBlock,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	282 blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	283 if (rv != SECSuccess) {
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	284 return SECFailure;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	285 }
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	286 /* make up for the out of order CBC decryption */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	287 XOR_BLOCK(Pn, Cn_2, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	288 XOR_BLOCK(Pn, Cn, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	289 /* reset iv to Cn */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	290 PORT_Memcpy(cts->iv, Cn, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	291 /* This makes Cn the last block for the next decrypt operation, which
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	292 * matches the encrypt. We don't care about the contexts of last block,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	293 * only the side effect of setting the internal IV */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	294 (void) (*cts->cipher)(cts->context, lastBlock, &tmpLen, blocksize, Cn,
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	295 blocksize, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	296 /* clear last block. At this point last block contains Pn xor Cn_1 xor
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	297 * Cn_2, both of with an attacker would know, so we need to clear this
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	298 * buffer out */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	299 PORT_Memset(lastBlock, 0, blocksize);
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	300 /* Cn, Cn_1, and Cn_2 have encrypted data, so no need to clear them */
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	301 return SECSuccess;
1e5118fa0cb1 This is NSS with a Cmake Buildsyste Andre Heinecke <andre.heinecke@intevation.de> parents: diff changeset	302 }

Mercurial > trustbridge > nss-cmake-static

annotate nss/lib/freebl/cts.c @ 0:1e5118fa0cb1