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: #include "seccomon.h"
michael@0: #include "secoid.h"
michael@0: #include "secasn1.h"
michael@0: #include "pkcs11.h"
michael@0: #include "pk11func.h"
michael@0: #include "pk11sdr.h"
michael@0: 
michael@0: /*
michael@0:  * Data structure and template for encoding the result of an SDR operation
michael@0:  *  This is temporary.  It should include the algorithm ID of the encryption mechanism
michael@0:  */
michael@0: struct SDRResult
michael@0: {
michael@0:   SECItem keyid;
michael@0:   SECAlgorithmID alg;
michael@0:   SECItem data;
michael@0: };
michael@0: typedef struct SDRResult SDRResult;
michael@0: 
michael@0: SEC_ASN1_MKSUB(SECOID_AlgorithmIDTemplate)
michael@0: 
michael@0: static SEC_ASN1Template template[] = {
michael@0:   { SEC_ASN1_SEQUENCE, 0, NULL, sizeof (SDRResult) },
michael@0:   { SEC_ASN1_OCTET_STRING, offsetof(SDRResult, keyid) },
michael@0:   { SEC_ASN1_INLINE | SEC_ASN1_XTRN, offsetof(SDRResult, alg),
michael@0:     SEC_ASN1_SUB(SECOID_AlgorithmIDTemplate) },
michael@0:   { SEC_ASN1_OCTET_STRING, offsetof(SDRResult, data) },
michael@0:   { 0 }
michael@0: };
michael@0: 
michael@0: static unsigned char keyID[] = {
michael@0:   0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
michael@0:   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01
michael@0: };
michael@0: 
michael@0: static SECItem keyIDItem = {
michael@0:   0,
michael@0:   keyID,
michael@0:   sizeof keyID
michael@0: };
michael@0: 
michael@0: /* local utility function for padding an incoming data block
michael@0:  * to the mechanism block size.
michael@0:  */
michael@0: static SECStatus
michael@0: padBlock(SECItem *data, int blockSize, SECItem *result)
michael@0: {
michael@0:   SECStatus rv = SECSuccess;
michael@0:   int padLength;
michael@0:   unsigned int i;
michael@0: 
michael@0:   result->data = 0;
michael@0:   result->len = 0;
michael@0: 
michael@0:   /* This algorithm always adds to the block (to indicate the number
michael@0:    * of pad bytes).  So allocate a block large enough.
michael@0:    */
michael@0:   padLength = blockSize - (data->len % blockSize);
michael@0:   result->len = data->len + padLength;
michael@0:   result->data = (unsigned char *)PORT_Alloc(result->len);
michael@0: 
michael@0:   /* Copy the data */
michael@0:   PORT_Memcpy(result->data, data->data, data->len);
michael@0: 
michael@0:   /* Add the pad values */
michael@0:   for(i = data->len; i < result->len; i++)
michael@0:     result->data[i] = (unsigned char)padLength;
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: static SECStatus
michael@0: unpadBlock(SECItem *data, int blockSize, SECItem *result)
michael@0: {
michael@0:   SECStatus rv = SECSuccess;
michael@0:   int padLength;
michael@0:   unsigned int i;
michael@0: 
michael@0:   result->data = 0;
michael@0:   result->len = 0;
michael@0: 
michael@0:   /* Remove the padding from the end if the input data */
michael@0:   if (data->len == 0 || data->len % blockSize  != 0) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   padLength = data->data[data->len-1];
michael@0:   if (padLength > blockSize) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   /* verify padding */
michael@0:   for (i=data->len - padLength; i < data->len; i++) {
michael@0:     if (data->data[i] != padLength) {
michael@0: 	rv = SECFailure;
michael@0: 	goto loser;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   result->len = data->len - padLength;
michael@0:   result->data = (unsigned char *)PORT_Alloc(result->len);
michael@0:   if (!result->data) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   PORT_Memcpy(result->data, data->data, result->len);
michael@0: 
michael@0:   if (padLength < 2) {
michael@0:     return SECWouldBlock;
michael@0:   }
michael@0: 
michael@0: loser:
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: static PRLock *pk11sdrLock = NULL;
michael@0: 
michael@0: void
michael@0: pk11sdr_Init (void)
michael@0: {
michael@0:    pk11sdrLock = PR_NewLock();
michael@0: }
michael@0: 
michael@0: void
michael@0: pk11sdr_Shutdown(void)
michael@0: {
michael@0:     if (pk11sdrLock) {
michael@0: 	PR_DestroyLock(pk11sdrLock);
michael@0: 	pk11sdrLock = NULL;
michael@0:     }
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * PK11SDR_Encrypt
michael@0:  *  Encrypt a block of data using the symmetric key identified.  The result
michael@0:  *  is an ASN.1 (DER) encoded block of keyid, params and data.
michael@0:  */
michael@0: SECStatus
michael@0: PK11SDR_Encrypt(SECItem *keyid, SECItem *data, SECItem *result, void *cx)
michael@0: {
michael@0:   SECStatus rv = SECSuccess;
michael@0:   PK11SlotInfo *slot = 0;
michael@0:   PK11SymKey *key = 0;
michael@0:   SECItem *params = 0;
michael@0:   PK11Context *ctx = 0;
michael@0:   CK_MECHANISM_TYPE type;
michael@0:   SDRResult sdrResult;
michael@0:   SECItem paddedData;
michael@0:   SECItem *pKeyID;
michael@0:   PLArenaPool *arena = 0;
michael@0: 
michael@0:   /* Initialize */
michael@0:   paddedData.len = 0;
michael@0:   paddedData.data = 0;
michael@0: 
michael@0:   arena = PORT_NewArena(SEC_ASN1_DEFAULT_ARENA_SIZE);
michael@0:   if (!arena) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   /* 1. Locate the requested keyid, or the default key (which has a keyid)
michael@0:    * 2. Create an encryption context
michael@0:    * 3. Encrypt
michael@0:    * 4. Encode the results (using ASN.1)
michael@0:    */
michael@0: 
michael@0:   slot = PK11_GetInternalKeySlot();
michael@0:   if (!slot) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   /* Use triple-DES */
michael@0:   type = CKM_DES3_CBC;
michael@0: 
michael@0:   /*
michael@0:    * Login to the internal token before we look for the key, otherwise we
michael@0:    * won't find it.
michael@0:    */
michael@0:   rv = PK11_Authenticate(slot, PR_TRUE, cx);
michael@0:   if (rv != SECSuccess) goto loser;
michael@0: 
michael@0:   /* Find the key to use */
michael@0:   pKeyID = keyid;
michael@0:   if (pKeyID->len == 0) {
michael@0: 	  pKeyID = &keyIDItem;  /* Use default value */
michael@0: 
michael@0: 	  /* put in a course lock to prevent a race between not finding the 
michael@0: 	   * key and creating  one.
michael@0: 	   */
michael@0: 
michael@0: 	  if (pk11sdrLock) PR_Lock(pk11sdrLock);
michael@0: 
michael@0: 	  /* Try to find the key */
michael@0: 	  key = PK11_FindFixedKey(slot, type, pKeyID, cx);
michael@0: 	  
michael@0: 	  /* If the default key doesn't exist yet, try to create it */
michael@0: 	  if (!key) key = PK11_GenDES3TokenKey(slot, pKeyID, cx);
michael@0: 	  if (pk11sdrLock) PR_Unlock(pk11sdrLock);
michael@0:   } else {
michael@0: 	  key = PK11_FindFixedKey(slot, type, pKeyID, cx);
michael@0:   }
michael@0: 
michael@0:   if (!key) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   params = PK11_GenerateNewParam(type, key);
michael@0:   if (!params) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   ctx = PK11_CreateContextBySymKey(type, CKA_ENCRYPT, key, params);
michael@0:   if (!ctx) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   rv = padBlock(data, PK11_GetBlockSize(type, 0), &paddedData);
michael@0:   if (rv != SECSuccess) goto loser;
michael@0: 
michael@0:   sdrResult.data.len = paddedData.len;
michael@0:   sdrResult.data.data = (unsigned char *)PORT_ArenaAlloc(arena, sdrResult.data.len);
michael@0: 
michael@0:   rv = PK11_CipherOp(ctx, sdrResult.data.data, (int*)&sdrResult.data.len, sdrResult.data.len,
michael@0:                      paddedData.data, paddedData.len);
michael@0:   if (rv != SECSuccess) goto loser;
michael@0: 
michael@0:   PK11_Finalize(ctx);
michael@0: 
michael@0:   sdrResult.keyid = *pKeyID;
michael@0: 
michael@0:   rv = PK11_ParamToAlgid(SEC_OID_DES_EDE3_CBC, params, arena, &sdrResult.alg);
michael@0:   if (rv != SECSuccess) goto loser;
michael@0: 
michael@0:   if (!SEC_ASN1EncodeItem(0, result, &sdrResult, template)) { rv = SECFailure; goto loser; }
michael@0: 
michael@0: loser:
michael@0:   SECITEM_ZfreeItem(&paddedData, PR_FALSE);
michael@0:   if (arena) PORT_FreeArena(arena, PR_TRUE);
michael@0:   if (ctx) PK11_DestroyContext(ctx, PR_TRUE);
michael@0:   if (params) SECITEM_ZfreeItem(params, PR_TRUE);
michael@0:   if (key) PK11_FreeSymKey(key);
michael@0:   if (slot) PK11_FreeSlot(slot);
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: /* decrypt a block */
michael@0: static SECStatus
michael@0: pk11Decrypt(PK11SlotInfo *slot, PLArenaPool *arena, 
michael@0: 	    CK_MECHANISM_TYPE type, PK11SymKey *key, 
michael@0: 	    SECItem *params, SECItem *in, SECItem *result)
michael@0: {
michael@0:   PK11Context *ctx = 0;
michael@0:   SECItem paddedResult;
michael@0:   SECStatus rv;
michael@0: 
michael@0:   paddedResult.len = 0;
michael@0:   paddedResult.data = 0;
michael@0: 
michael@0:   ctx = PK11_CreateContextBySymKey(type, CKA_DECRYPT, key, params);
michael@0:   if (!ctx) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   paddedResult.len = in->len;
michael@0:   paddedResult.data = PORT_ArenaAlloc(arena, paddedResult.len);
michael@0: 
michael@0:   rv = PK11_CipherOp(ctx, paddedResult.data, 
michael@0: 			(int*)&paddedResult.len, paddedResult.len,
michael@0: 			in->data, in->len);
michael@0:   if (rv != SECSuccess) goto loser;
michael@0: 
michael@0:   PK11_Finalize(ctx);
michael@0: 
michael@0:   /* Remove the padding */
michael@0:   rv = unpadBlock(&paddedResult, PK11_GetBlockSize(type, 0), result);
michael@0:   if (rv) goto loser;
michael@0: 
michael@0: loser:
michael@0:   if (ctx) PK11_DestroyContext(ctx, PR_TRUE);
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * PK11SDR_Decrypt
michael@0:  *  Decrypt a block of data produced by PK11SDR_Encrypt.  The key used is identified
michael@0:  *  by the keyid field within the input.
michael@0:  */
michael@0: SECStatus
michael@0: PK11SDR_Decrypt(SECItem *data, SECItem *result, void *cx)
michael@0: {
michael@0:   SECStatus rv = SECSuccess;
michael@0:   PK11SlotInfo *slot = 0;
michael@0:   PK11SymKey *key = 0;
michael@0:   CK_MECHANISM_TYPE type;
michael@0:   SDRResult sdrResult;
michael@0:   SECItem *params = 0;
michael@0:   SECItem possibleResult = { 0, NULL, 0 };
michael@0:   PLArenaPool *arena = 0;
michael@0: 
michael@0:   arena = PORT_NewArena(SEC_ASN1_DEFAULT_ARENA_SIZE);
michael@0:   if (!arena) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   /* Decode the incoming data */
michael@0:   memset(&sdrResult, 0, sizeof sdrResult);
michael@0:   rv = SEC_QuickDERDecodeItem(arena, &sdrResult, template, data);
michael@0:   if (rv != SECSuccess) goto loser;  /* Invalid format */
michael@0: 
michael@0:   /* Find the slot and key for the given keyid */
michael@0:   slot = PK11_GetInternalKeySlot();
michael@0:   if (!slot) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   rv = PK11_Authenticate(slot, PR_TRUE, cx);
michael@0:   if (rv != SECSuccess) goto loser;
michael@0: 
michael@0:   /* Get the parameter values from the data */
michael@0:   params = PK11_ParamFromAlgid(&sdrResult.alg);
michael@0:   if (!params) { rv = SECFailure; goto loser; }
michael@0: 
michael@0:   /* Use triple-DES (Should look up the algorithm) */
michael@0:   type = CKM_DES3_CBC;
michael@0:   key = PK11_FindFixedKey(slot, type, &sdrResult.keyid, cx);
michael@0:   if (!key) { 
michael@0: 	rv = SECFailure;  
michael@0:   } else {
michael@0: 	rv = pk11Decrypt(slot, arena, type, key, params, 
michael@0: 			&sdrResult.data, result);
michael@0:   }
michael@0: 
michael@0:   /*
michael@0:    * if the pad value was too small (1 or 2), then it's statistically
michael@0:    * 'likely' that (1 in 256) that we may not have the correct key.
michael@0:    * Check the other keys for a better match. If we find none, use
michael@0:    * this result.
michael@0:    */
michael@0:   if (rv == SECWouldBlock) {
michael@0: 	possibleResult = *result;
michael@0:   }
michael@0: 
michael@0:   /*
michael@0:    * handle the case where your key indicies may have been broken
michael@0:    */
michael@0:   if (rv != SECSuccess) {
michael@0: 	PK11SymKey *keyList = PK11_ListFixedKeysInSlot(slot, NULL, cx);
michael@0: 	PK11SymKey *testKey = NULL;
michael@0: 	PK11SymKey *nextKey = NULL;
michael@0: 
michael@0: 	for (testKey = keyList; testKey; 
michael@0: 				testKey = PK11_GetNextSymKey(testKey)) {
michael@0: 	    rv = pk11Decrypt(slot, arena, type, testKey, params, 
michael@0: 			     &sdrResult.data, result);
michael@0: 	    if (rv == SECSuccess) {
michael@0: 		break;
michael@0: 	    } 
michael@0: 	    /* found a close match. If it's our first remember it */
michael@0: 	    if (rv == SECWouldBlock) {
michael@0: 		if (possibleResult.data) {
michael@0: 		    /* this is unlikely but possible. If we hit this condition,
michael@0: 		     * we have no way of knowing which possibility to prefer.
michael@0: 		     * in this case we just match the key the application
michael@0: 		     * thought was the right one */
michael@0: 		    SECITEM_ZfreeItem(result, PR_FALSE);
michael@0: 		} else {
michael@0: 		    possibleResult = *result;
michael@0: 		}
michael@0: 	    }
michael@0: 	}
michael@0: 
michael@0: 	/* free the list */
michael@0: 	for (testKey = keyList; testKey; testKey = nextKey) {
michael@0: 	    nextKey = PK11_GetNextSymKey(testKey);
michael@0: 	    PK11_FreeSymKey(testKey);
michael@0: 	}
michael@0:   }
michael@0: 
michael@0:   /* we didn't find a better key, use the one with a small pad value */
michael@0:   if ((rv != SECSuccess) && (possibleResult.data)) {
michael@0: 	*result = possibleResult;
michael@0: 	possibleResult.data = NULL;
michael@0: 	rv = SECSuccess;
michael@0:   }
michael@0: 
michael@0: loser:
michael@0:   if (arena) PORT_FreeArena(arena, PR_TRUE);
michael@0:   if (key) PK11_FreeSymKey(key);
michael@0:   if (params) SECITEM_ZfreeItem(params, PR_TRUE);
michael@0:   if (slot) PK11_FreeSlot(slot);
michael@0:   if (possibleResult.data) SECITEM_ZfreeItem(&possibleResult, PR_FALSE);
michael@0: 
michael@0:   return rv;
michael@0: }