michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifdef FREEBL_NO_DEPEND
michael@0: #include "stubs.h"
michael@0: #endif
michael@0: 
michael@0: #include "secport.h"
michael@0: #include "hasht.h"
michael@0: #include "blapit.h"
michael@0: #include "alghmac.h"
michael@0: #include "secerr.h"
michael@0: 
michael@0: #define HMAC_PAD_SIZE HASH_BLOCK_LENGTH_MAX
michael@0: 
michael@0: struct HMACContextStr {
michael@0:     void *hash;
michael@0:     const SECHashObject *hashobj;
michael@0:     PRBool        wasAllocated;
michael@0:     unsigned char ipad[HMAC_PAD_SIZE];
michael@0:     unsigned char opad[HMAC_PAD_SIZE];
michael@0: };
michael@0: 
michael@0: void
michael@0: HMAC_Destroy(HMACContext *cx, PRBool freeit)
michael@0: {
michael@0:     if (cx == NULL)
michael@0: 	return;
michael@0: 
michael@0:     PORT_Assert(!freeit == !cx->wasAllocated);
michael@0:     if (cx->hash != NULL) {
michael@0: 	cx->hashobj->destroy(cx->hash, PR_TRUE);
michael@0: 	PORT_Memset(cx, 0, sizeof *cx);
michael@0:     }
michael@0:     if (freeit)
michael@0: 	PORT_Free(cx);
michael@0: }
michael@0: 
michael@0: SECStatus
michael@0: HMAC_Init( HMACContext * cx, const SECHashObject *hash_obj, 
michael@0: 	   const unsigned char *secret, unsigned int secret_len, PRBool isFIPS)
michael@0: {
michael@0:     unsigned int i;
michael@0:     unsigned char hashed_secret[HASH_LENGTH_MAX];
michael@0: 
michael@0:     /* required by FIPS 198 Section 3 */
michael@0:     if (isFIPS && secret_len < hash_obj->length/2) {
michael@0: 	PORT_SetError(SEC_ERROR_INVALID_ARGS);
michael@0: 	return SECFailure;
michael@0:     }
michael@0:     if (cx == NULL) {
michael@0: 	PORT_SetError(SEC_ERROR_INVALID_ARGS);
michael@0: 	return SECFailure;
michael@0:     }
michael@0:     cx->wasAllocated = PR_FALSE;
michael@0:     cx->hashobj = hash_obj;
michael@0:     cx->hash = cx->hashobj->create();
michael@0:     if (cx->hash == NULL)
michael@0: 	goto loser;
michael@0: 
michael@0:     if (secret_len > cx->hashobj->blocklength) {
michael@0: 	cx->hashobj->begin( cx->hash);
michael@0: 	cx->hashobj->update(cx->hash, secret, secret_len);
michael@0: 	PORT_Assert(cx->hashobj->length <= sizeof hashed_secret);
michael@0: 	cx->hashobj->end(   cx->hash, hashed_secret, &secret_len, 
michael@0: 	                 sizeof hashed_secret);
michael@0: 	if (secret_len != cx->hashobj->length) {
michael@0: 	    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
michael@0: 	    goto loser;
michael@0: 	}
michael@0: 	secret = (const unsigned char *)&hashed_secret[0];
michael@0:     }
michael@0: 
michael@0:     PORT_Memset(cx->ipad, 0x36, cx->hashobj->blocklength);
michael@0:     PORT_Memset(cx->opad, 0x5c, cx->hashobj->blocklength);
michael@0: 
michael@0:     /* fold secret into padding */
michael@0:     for (i = 0; i < secret_len; i++) {
michael@0: 	cx->ipad[i] ^= secret[i];
michael@0: 	cx->opad[i] ^= secret[i];
michael@0:     }
michael@0:     PORT_Memset(hashed_secret, 0, sizeof hashed_secret);
michael@0:     return SECSuccess;
michael@0: 
michael@0: loser:
michael@0:     PORT_Memset(hashed_secret, 0, sizeof hashed_secret);
michael@0:     if (cx->hash != NULL)
michael@0: 	cx->hashobj->destroy(cx->hash, PR_TRUE);
michael@0:     return SECFailure;
michael@0: }
michael@0: 
michael@0: HMACContext *
michael@0: HMAC_Create(const SECHashObject *hash_obj, const unsigned char *secret, 
michael@0:             unsigned int secret_len, PRBool isFIPS)
michael@0: {
michael@0:     SECStatus rv;
michael@0:     HMACContext * cx = PORT_ZNew(HMACContext);
michael@0:     if (cx == NULL)
michael@0: 	return NULL;
michael@0:     rv = HMAC_Init(cx, hash_obj, secret, secret_len, isFIPS);
michael@0:     cx->wasAllocated = PR_TRUE;
michael@0:     if (rv != SECSuccess) {
michael@0: 	PORT_Free(cx); /* contains no secret info */
michael@0: 	cx = NULL;
michael@0:     }
michael@0:     return cx;
michael@0: }
michael@0: 
michael@0: void
michael@0: HMAC_Begin(HMACContext *cx)
michael@0: {
michael@0:     /* start inner hash */
michael@0:     cx->hashobj->begin(cx->hash);
michael@0:     cx->hashobj->update(cx->hash, cx->ipad, cx->hashobj->blocklength);
michael@0: }
michael@0: 
michael@0: void
michael@0: HMAC_Update(HMACContext *cx, const unsigned char *data, unsigned int data_len)
michael@0: {
michael@0:     cx->hashobj->update(cx->hash, data, data_len);
michael@0: }
michael@0: 
michael@0: SECStatus
michael@0: HMAC_Finish(HMACContext *cx, unsigned char *result, unsigned int *result_len,
michael@0: 	    unsigned int max_result_len)
michael@0: {
michael@0:     if (max_result_len < cx->hashobj->length) {
michael@0: 	PORT_SetError(SEC_ERROR_INVALID_ARGS);
michael@0: 	return SECFailure;
michael@0:     }
michael@0: 
michael@0:     cx->hashobj->end(cx->hash, result, result_len, max_result_len);
michael@0:     if (*result_len != cx->hashobj->length)
michael@0: 	return SECFailure;
michael@0: 
michael@0:     cx->hashobj->begin(cx->hash);
michael@0:     cx->hashobj->update(cx->hash, cx->opad, cx->hashobj->blocklength);
michael@0:     cx->hashobj->update(cx->hash, result, *result_len);
michael@0:     cx->hashobj->end(cx->hash, result, result_len, max_result_len);
michael@0:     return SECSuccess;
michael@0: }
michael@0: 
michael@0: HMACContext *
michael@0: HMAC_Clone(HMACContext *cx)
michael@0: {
michael@0:     HMACContext *newcx;
michael@0: 
michael@0:     newcx = (HMACContext*)PORT_ZAlloc(sizeof(HMACContext));
michael@0:     if (newcx == NULL)
michael@0: 	goto loser;
michael@0: 
michael@0:     newcx->wasAllocated = PR_TRUE;
michael@0:     newcx->hashobj = cx->hashobj;
michael@0:     newcx->hash = cx->hashobj->clone(cx->hash);
michael@0:     if (newcx->hash == NULL)
michael@0: 	goto loser;
michael@0:     PORT_Memcpy(newcx->ipad, cx->ipad, cx->hashobj->blocklength);
michael@0:     PORT_Memcpy(newcx->opad, cx->opad, cx->hashobj->blocklength);
michael@0:     return newcx;
michael@0: 
michael@0: loser:
michael@0:     HMAC_Destroy(newcx, PR_TRUE);
michael@0:     return NULL;
michael@0: }