DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (fddffdeab170)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383
/*
 * aeskeywrap.c - implement AES Key Wrap algorithm from RFC 3394
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifdef FREEBL_NO_DEPEND
#include "stubs.h"
#endif

#include "prcpucfg.h"
#if defined(IS_LITTLE_ENDIAN) || defined(SHA_NO_LONG_LONG)
#define BIG_ENDIAN_WITH_64_BIT_REGISTERS 0
#else
#define BIG_ENDIAN_WITH_64_BIT_REGISTERS 1
#endif
#include "prtypes.h"	/* for PRUintXX */
#include "secport.h"	/* for PORT_XXX */
#include "secerr.h"
#include "blapi.h"	/* for AES_ functions */
#include "rijndael.h"

struct AESKeyWrapContextStr {
     unsigned char iv[AES_KEY_WRAP_IV_BYTES];
     AESContext    aescx;
};

/******************************************/
/*
** AES key wrap algorithm, RFC 3394
*/

AESKeyWrapContext * 
AESKeyWrap_AllocateContext(void)
{
    AESKeyWrapContext * cx = PORT_New(AESKeyWrapContext);
    return cx;
}

SECStatus  
AESKeyWrap_InitContext(AESKeyWrapContext *cx, 
		       const unsigned char *key, 
		       unsigned int keylen,
		       const unsigned char *iv, 
		       int x1,
		       unsigned int encrypt,
		       unsigned int x2)
{
    SECStatus rv = SECFailure;
    if (!cx) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
    	return SECFailure;
    }
    if (iv) {
    	memcpy(cx->iv, iv, sizeof cx->iv);
    } else {
	memset(cx->iv, 0xA6, sizeof cx->iv);
    }
    rv = AES_InitContext(&cx->aescx, key, keylen, NULL, NSS_AES, encrypt, 
                                  AES_BLOCK_SIZE);
    return rv;
}

/*
** Create a new AES context suitable for AES encryption/decryption.
** 	"key" raw key data
** 	"keylen" the number of bytes of key data (16, 24, or 32)
*/
extern AESKeyWrapContext *
AESKeyWrap_CreateContext(const unsigned char *key, const unsigned char *iv, 
                         int encrypt, unsigned int keylen)
{
    SECStatus rv;
    AESKeyWrapContext * cx = AESKeyWrap_AllocateContext();
    if (!cx) 
    	return NULL;	/* error is already set */
    rv = AESKeyWrap_InitContext(cx, key, keylen, iv, 0, encrypt, 0);
    if (rv != SECSuccess) {
        PORT_Free(cx);
	cx = NULL; 	/* error should already be set */
    }
    return cx;
}

/*
** Destroy a AES KeyWrap context.
**	"cx" the context
**	"freeit" if PR_TRUE then free the object as well as its sub-objects
*/
extern void 
AESKeyWrap_DestroyContext(AESKeyWrapContext *cx, PRBool freeit)
{
    if (cx) {
	AES_DestroyContext(&cx->aescx, PR_FALSE);
/*	memset(cx, 0, sizeof *cx); */
	if (freeit)
	    PORT_Free(cx);
    }
}

#if !BIG_ENDIAN_WITH_64_BIT_REGISTERS

/* The AES Key Wrap algorithm has 64-bit values that are ALWAYS big-endian
** (Most significant byte first) in memory.  The only ALU operations done
** on them are increment, decrement, and XOR.  So, on little-endian CPUs,
** and on CPUs that lack 64-bit registers, these big-endian 64-bit operations
** are simulated in the following code.  This is thought to be faster and
** simpler than trying to convert the data to little-endian and back.
*/

/* A and T point to two 64-bit values stored most signficant byte first
** (big endian).  This function increments the 64-bit value T, and then
** XORs it with A, changing A.
*/ 
static void
increment_and_xor(unsigned char *A, unsigned char *T)
{
    if (!++T[7])
        if (!++T[6])
	    if (!++T[5])
		if (!++T[4])
		    if (!++T[3])
			if (!++T[2])
			    if (!++T[1])
				 ++T[0];

    A[0] ^= T[0];
    A[1] ^= T[1];
    A[2] ^= T[2];
    A[3] ^= T[3];
    A[4] ^= T[4];
    A[5] ^= T[5];
    A[6] ^= T[6];
    A[7] ^= T[7];
}

/* A and T point to two 64-bit values stored most signficant byte first
** (big endian).  This function XORs T with A, giving a new A, then 
** decrements the 64-bit value T.
*/ 
static void
xor_and_decrement(unsigned char *A, unsigned char *T)
{
    A[0] ^= T[0];
    A[1] ^= T[1];
    A[2] ^= T[2];
    A[3] ^= T[3];
    A[4] ^= T[4];
    A[5] ^= T[5];
    A[6] ^= T[6];
    A[7] ^= T[7];

    if (!T[7]--)
        if (!T[6]--)
	    if (!T[5]--)
		if (!T[4]--)
		    if (!T[3]--)
			if (!T[2]--)
			    if (!T[1]--)
				 T[0]--;

}

/* Given an unsigned long t (in host byte order), store this value as a
** 64-bit big-endian value (MSB first) in *pt.
*/
static void
set_t(unsigned char *pt, unsigned long t)
{
    pt[7] = (unsigned char)t; t >>= 8;
    pt[6] = (unsigned char)t; t >>= 8;
    pt[5] = (unsigned char)t; t >>= 8;
    pt[4] = (unsigned char)t; t >>= 8;
    pt[3] = (unsigned char)t; t >>= 8;
    pt[2] = (unsigned char)t; t >>= 8;
    pt[1] = (unsigned char)t; t >>= 8;
    pt[0] = (unsigned char)t;
}

#endif

/*
** Perform AES key wrap.
**	"cx" the context
**	"output" the output buffer to store the encrypted data.
**	"outputLen" how much data is stored in "output". Set by the routine
**	   after some data is stored in output.
**	"maxOutputLen" the maximum amount of data that can ever be
**	   stored in "output"
**	"input" the input data
**	"inputLen" the amount of input data
*/
extern SECStatus 
AESKeyWrap_Encrypt(AESKeyWrapContext *cx, unsigned char *output,
            unsigned int *pOutputLen, unsigned int maxOutputLen,
            const unsigned char *input, unsigned int inputLen)
{
    PRUint64 *     R          = NULL;
    unsigned int   nBlocks;
    unsigned int   i, j;
    unsigned int   aesLen     = AES_BLOCK_SIZE;
    unsigned int   outLen     = inputLen + AES_KEY_WRAP_BLOCK_SIZE;
    SECStatus      s          = SECFailure;
    /* These PRUint64s are ALWAYS big endian, regardless of CPU orientation. */
    PRUint64       t;
    PRUint64       B[2];

#define A B[0]

    /* Check args */
    if (!inputLen || 0 != inputLen % AES_KEY_WRAP_BLOCK_SIZE) {
	PORT_SetError(SEC_ERROR_INPUT_LEN);
	return s;
    }
#ifdef maybe
    if (!output && pOutputLen) {	/* caller is asking for output size */
    	*pOutputLen = outLen;
	return SECSuccess;
    }
#endif
    if (maxOutputLen < outLen) {
	PORT_SetError(SEC_ERROR_OUTPUT_LEN);
	return s;
    }
    if (cx == NULL || output == NULL || input == NULL) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return s;
    }
    nBlocks = inputLen / AES_KEY_WRAP_BLOCK_SIZE;
    R = PORT_NewArray(PRUint64, nBlocks + 1);
    if (!R)
    	return s;	/* error is already set. */
    /* 
    ** 1) Initialize variables.
    */
    memcpy(&A, cx->iv, AES_KEY_WRAP_IV_BYTES);
    memcpy(&R[1], input, inputLen);
#if BIG_ENDIAN_WITH_64_BIT_REGISTERS
    t = 0;
#else
    memset(&t, 0, sizeof t);
#endif
    /* 
    ** 2) Calculate intermediate values.
    */
    for (j = 0; j < 6; ++j) {
    	for (i = 1; i <= nBlocks; ++i) {
	    B[1] = R[i];
	    s = AES_Encrypt(&cx->aescx, (unsigned char *)B, &aesLen, 
	                    sizeof B,  (unsigned char *)B, sizeof B);
	    if (s != SECSuccess) 
	        break;
	    R[i] = B[1];
	    /* here, increment t and XOR A with t (in big endian order); */
#if BIG_ENDIAN_WITH_64_BIT_REGISTERS
   	    A ^= ++t; 
#else
	    increment_and_xor((unsigned char *)&A, (unsigned char *)&t);
#endif
	}
    }
    /* 
    ** 3) Output the results.
    */
    if (s == SECSuccess) {
    	R[0] =  A;
	memcpy(output, &R[0], outLen);
	if (pOutputLen)
	    *pOutputLen = outLen;
    } else if (pOutputLen) {
    	*pOutputLen = 0;
    }
    PORT_ZFree(R, outLen);
    return s;
}
#undef A

/*
** Perform AES key unwrap.
**	"cx" the context
**	"output" the output buffer to store the decrypted data.
**	"outputLen" how much data is stored in "output". Set by the routine
**	   after some data is stored in output.
**	"maxOutputLen" the maximum amount of data that can ever be
**	   stored in "output"
**	"input" the input data
**	"inputLen" the amount of input data
*/
extern SECStatus 
AESKeyWrap_Decrypt(AESKeyWrapContext *cx, unsigned char *output,
            unsigned int *pOutputLen, unsigned int maxOutputLen,
            const unsigned char *input, unsigned int inputLen)
{
    PRUint64 *     R          = NULL;
    unsigned int   nBlocks;
    unsigned int   i, j;
    unsigned int   aesLen     = AES_BLOCK_SIZE;
    unsigned int   outLen;
    SECStatus      s          = SECFailure;
    /* These PRUint64s are ALWAYS big endian, regardless of CPU orientation. */
    PRUint64       t;
    PRUint64       B[2];

#define A B[0]

    /* Check args */
    if (inputLen < 3 * AES_KEY_WRAP_BLOCK_SIZE || 
        0 != inputLen % AES_KEY_WRAP_BLOCK_SIZE) {
	PORT_SetError(SEC_ERROR_INPUT_LEN);
	return s;
    }
    outLen = inputLen - AES_KEY_WRAP_BLOCK_SIZE;
#ifdef maybe
    if (!output && pOutputLen) {	/* caller is asking for output size */
    	*pOutputLen = outLen;
	return SECSuccess;
    }
#endif
    if (maxOutputLen < outLen) {
	PORT_SetError(SEC_ERROR_OUTPUT_LEN);
	return s;
    }
    if (cx == NULL || output == NULL || input == NULL) {
	PORT_SetError(SEC_ERROR_INVALID_ARGS);
	return s;
    }
    nBlocks = inputLen / AES_KEY_WRAP_BLOCK_SIZE;
    R = PORT_NewArray(PRUint64, nBlocks);
    if (!R)
    	return s;	/* error is already set. */
    nBlocks--;
    /* 
    ** 1) Initialize variables.
    */
    memcpy(&R[0], input, inputLen);
    A = R[0];
#if BIG_ENDIAN_WITH_64_BIT_REGISTERS
    t = 6UL * nBlocks;
#else
    set_t((unsigned char *)&t, 6UL * nBlocks);
#endif
    /* 
    ** 2) Calculate intermediate values.
    */
    for (j = 0; j < 6; ++j) {
    	for (i = nBlocks; i; --i) {
	    /* here, XOR A with t (in big endian order) and decrement t; */
#if BIG_ENDIAN_WITH_64_BIT_REGISTERS
   	    A ^= t--; 
#else
	    xor_and_decrement((unsigned char *)&A, (unsigned char *)&t);
#endif
	    B[1] = R[i];
	    s = AES_Decrypt(&cx->aescx, (unsigned char *)B, &aesLen, 
	                    sizeof B,  (unsigned char *)B, sizeof B);
	    if (s != SECSuccess) 
	        break;
	    R[i] = B[1];
	}
    }
    /* 
    ** 3) Output the results.
    */
    if (s == SECSuccess) {
	int bad = memcmp(&A, cx->iv, AES_KEY_WRAP_IV_BYTES);
	if (!bad) {
	    memcpy(output, &R[1], outLen);
	    if (pOutputLen)
		*pOutputLen = outLen;
	} else {
	    s = SECFailure;
	    PORT_SetError(SEC_ERROR_BAD_DATA);
	    if (pOutputLen) 
		*pOutputLen = 0;
    	}
    } else if (pOutputLen) {
    	*pOutputLen = 0;
    }
    PORT_ZFree(R, inputLen);
    return s;
}
#undef A