diff options
Diffstat (limited to 'security/nss/lib/pk11wrap/pk11sdr.c')
| -rw-r--r-- | security/nss/lib/pk11wrap/pk11sdr.c | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/security/nss/lib/pk11wrap/pk11sdr.c b/security/nss/lib/pk11wrap/pk11sdr.c new file mode 100644 index 0000000000..eb67bfba82 --- /dev/null +++ b/security/nss/lib/pk11wrap/pk11sdr.c @@ -0,0 +1,437 @@ +/* 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/. */ + +#include "seccomon.h" +#include "secoid.h" +#include "secasn1.h" +#include "pkcs11.h" +#include "pk11func.h" +#include "pk11sdr.h" + +/* + * Data structure and template for encoding the result of an SDR operation + * This is temporary. It should include the algorithm ID of the encryption mechanism + */ +struct SDRResult { + SECItem keyid; + SECAlgorithmID alg; + SECItem data; +}; +typedef struct SDRResult SDRResult; + +SEC_ASN1_MKSUB(SECOID_AlgorithmIDTemplate) + +static SEC_ASN1Template template[] = { + { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(SDRResult) }, + { SEC_ASN1_OCTET_STRING, offsetof(SDRResult, keyid) }, + { SEC_ASN1_INLINE | SEC_ASN1_XTRN, offsetof(SDRResult, alg), + SEC_ASN1_SUB(SECOID_AlgorithmIDTemplate) }, + { SEC_ASN1_OCTET_STRING, offsetof(SDRResult, data) }, + { 0 } +}; + +static unsigned char keyID[] = { + 0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 +}; + +static SECItem keyIDItem = { + 0, + keyID, + sizeof keyID +}; + +/* local utility function for padding an incoming data block + * to the mechanism block size. + */ +static SECStatus +padBlock(SECItem *data, int blockSize, SECItem *result) +{ + SECStatus rv = SECSuccess; + int padLength; + unsigned int i; + + result->data = 0; + result->len = 0; + + /* This algorithm always adds to the block (to indicate the number + * of pad bytes). So allocate a block large enough. + */ + padLength = blockSize - (data->len % blockSize); + result->len = data->len + padLength; + result->data = (unsigned char *)PORT_Alloc(result->len); + + /* Copy the data */ + PORT_Memcpy(result->data, data->data, data->len); + + /* Add the pad values */ + for (i = data->len; i < result->len; i++) + result->data[i] = (unsigned char)padLength; + + return rv; +} + +static SECStatus +unpadBlock(SECItem *data, int blockSize, SECItem *result) +{ + SECStatus rv = SECSuccess; + int padLength; + unsigned int i; + + result->data = 0; + result->len = 0; + + /* Remove the padding from the end if the input data */ + if (data->len == 0 || data->len % blockSize != 0) { + rv = SECFailure; + goto loser; + } + + padLength = data->data[data->len - 1]; + if (padLength > blockSize) { + rv = SECFailure; + goto loser; + } + + /* verify padding */ + for (i = data->len - padLength; i < data->len; i++) { + if (data->data[i] != padLength) { + rv = SECFailure; + goto loser; + } + } + + result->len = data->len - padLength; + result->data = (unsigned char *)PORT_Alloc(result->len); + if (!result->data) { + rv = SECFailure; + goto loser; + } + + PORT_Memcpy(result->data, data->data, result->len); + + if (padLength < 2) { + return SECWouldBlock; + } + +loser: + return rv; +} + +static PRLock *pk11sdrLock = NULL; + +void +pk11sdr_Init(void) +{ + pk11sdrLock = PR_NewLock(); +} + +void +pk11sdr_Shutdown(void) +{ + if (pk11sdrLock) { + PR_DestroyLock(pk11sdrLock); + pk11sdrLock = NULL; + } +} + +/* + * PK11SDR_Encrypt + * Encrypt a block of data using the symmetric key identified. The result + * is an ASN.1 (DER) encoded block of keyid, params and data. + */ +SECStatus +PK11SDR_Encrypt(SECItem *keyid, SECItem *data, SECItem *result, void *cx) +{ + SECStatus rv = SECSuccess; + PK11SlotInfo *slot = 0; + PK11SymKey *key = 0; + SECItem *params = 0; + PK11Context *ctx = 0; + CK_MECHANISM_TYPE type; + SDRResult sdrResult; + SECItem paddedData; + SECItem *pKeyID; + PLArenaPool *arena = 0; + + /* Initialize */ + paddedData.len = 0; + paddedData.data = 0; + + arena = PORT_NewArena(SEC_ASN1_DEFAULT_ARENA_SIZE); + if (!arena) { + rv = SECFailure; + goto loser; + } + + /* 1. Locate the requested keyid, or the default key (which has a keyid) + * 2. Create an encryption context + * 3. Encrypt + * 4. Encode the results (using ASN.1) + */ + + slot = PK11_GetInternalKeySlot(); + if (!slot) { + rv = SECFailure; + goto loser; + } + + /* Use triple-DES */ + type = CKM_DES3_CBC; + + /* + * Login to the internal token before we look for the key, otherwise we + * won't find it. + */ + rv = PK11_Authenticate(slot, PR_TRUE, cx); + if (rv != SECSuccess) + goto loser; + + /* Find the key to use */ + pKeyID = keyid; + if (pKeyID->len == 0) { + pKeyID = &keyIDItem; /* Use default value */ + + /* put in a course lock to prevent a race between not finding the + * key and creating one. + */ + + if (pk11sdrLock) + PR_Lock(pk11sdrLock); + + /* Try to find the key */ + key = PK11_FindFixedKey(slot, type, pKeyID, cx); + + /* If the default key doesn't exist yet, try to create it */ + if (!key) + key = PK11_GenDES3TokenKey(slot, pKeyID, cx); + if (pk11sdrLock) + PR_Unlock(pk11sdrLock); + } else { + key = PK11_FindFixedKey(slot, type, pKeyID, cx); + } + + if (!key) { + rv = SECFailure; + goto loser; + } + + params = PK11_GenerateNewParam(type, key); + if (!params) { + rv = SECFailure; + goto loser; + } + + ctx = PK11_CreateContextBySymKey(type, CKA_ENCRYPT, key, params); + if (!ctx) { + rv = SECFailure; + goto loser; + } + + rv = padBlock(data, PK11_GetBlockSize(type, 0), &paddedData); + if (rv != SECSuccess) + goto loser; + + sdrResult.data.len = paddedData.len; + sdrResult.data.data = (unsigned char *)PORT_ArenaAlloc(arena, sdrResult.data.len); + + rv = PK11_CipherOp(ctx, sdrResult.data.data, (int *)&sdrResult.data.len, sdrResult.data.len, + paddedData.data, paddedData.len); + if (rv != SECSuccess) + goto loser; + + PK11_Finalize(ctx); + + sdrResult.keyid = *pKeyID; + + rv = PK11_ParamToAlgid(SEC_OID_DES_EDE3_CBC, params, arena, &sdrResult.alg); + if (rv != SECSuccess) + goto loser; + + if (!SEC_ASN1EncodeItem(0, result, &sdrResult, template)) { + rv = SECFailure; + goto loser; + } + +loser: + SECITEM_ZfreeItem(&paddedData, PR_FALSE); + if (arena) + PORT_FreeArena(arena, PR_TRUE); + if (ctx) + PK11_DestroyContext(ctx, PR_TRUE); + if (params) + SECITEM_ZfreeItem(params, PR_TRUE); + if (key) + PK11_FreeSymKey(key); + if (slot) + PK11_FreeSlot(slot); + + return rv; +} + +/* decrypt a block */ +static SECStatus +pk11Decrypt(PK11SlotInfo *slot, PLArenaPool *arena, + CK_MECHANISM_TYPE type, PK11SymKey *key, + SECItem *params, SECItem *in, SECItem *result) +{ + PK11Context *ctx = 0; + SECItem paddedResult; + SECStatus rv; + + paddedResult.len = 0; + paddedResult.data = 0; + + ctx = PK11_CreateContextBySymKey(type, CKA_DECRYPT, key, params); + if (!ctx) { + rv = SECFailure; + goto loser; + } + + paddedResult.len = in->len; + paddedResult.data = PORT_ArenaAlloc(arena, paddedResult.len); + + rv = PK11_CipherOp(ctx, paddedResult.data, + (int *)&paddedResult.len, paddedResult.len, + in->data, in->len); + if (rv != SECSuccess) + goto loser; + + PK11_Finalize(ctx); + + /* Remove the padding */ + rv = unpadBlock(&paddedResult, PK11_GetBlockSize(type, 0), result); + if (rv) + goto loser; + +loser: + if (ctx) + PK11_DestroyContext(ctx, PR_TRUE); + return rv; +} + +/* + * PK11SDR_Decrypt + * Decrypt a block of data produced by PK11SDR_Encrypt. The key used is identified + * by the keyid field within the input. + */ +SECStatus +PK11SDR_Decrypt(SECItem *data, SECItem *result, void *cx) +{ + SECStatus rv = SECSuccess; + PK11SlotInfo *slot = 0; + PK11SymKey *key = 0; + CK_MECHANISM_TYPE type; + SDRResult sdrResult; + SECItem *params = 0; + SECItem possibleResult = { 0, NULL, 0 }; + PLArenaPool *arena = 0; + + arena = PORT_NewArena(SEC_ASN1_DEFAULT_ARENA_SIZE); + if (!arena) { + rv = SECFailure; + goto loser; + } + + /* Decode the incoming data */ + memset(&sdrResult, 0, sizeof sdrResult); + rv = SEC_QuickDERDecodeItem(arena, &sdrResult, template, data); + if (rv != SECSuccess) + goto loser; /* Invalid format */ + + /* Find the slot and key for the given keyid */ + slot = PK11_GetInternalKeySlot(); + if (!slot) { + rv = SECFailure; + goto loser; + } + + rv = PK11_Authenticate(slot, PR_TRUE, cx); + if (rv != SECSuccess) + goto loser; + + /* Get the parameter values from the data */ + params = PK11_ParamFromAlgid(&sdrResult.alg); + if (!params) { + rv = SECFailure; + goto loser; + } + + /* Use triple-DES (Should look up the algorithm) */ + type = CKM_DES3_CBC; + key = PK11_FindFixedKey(slot, type, &sdrResult.keyid, cx); + if (!key) { + rv = SECFailure; + } else { + rv = pk11Decrypt(slot, arena, type, key, params, + &sdrResult.data, result); + } + + /* + * if the pad value was too small (1 or 2), then it's statistically + * 'likely' that (1 in 256) that we may not have the correct key. + * Check the other keys for a better match. If we find none, use + * this result. + */ + if (rv == SECWouldBlock) { + possibleResult = *result; + } + + /* + * handle the case where your key indicies may have been broken + */ + if (rv != SECSuccess) { + PK11SymKey *keyList = PK11_ListFixedKeysInSlot(slot, NULL, cx); + PK11SymKey *testKey = NULL; + PK11SymKey *nextKey = NULL; + + for (testKey = keyList; testKey; + testKey = PK11_GetNextSymKey(testKey)) { + rv = pk11Decrypt(slot, arena, type, testKey, params, + &sdrResult.data, result); + if (rv == SECSuccess) { + break; + } + /* found a close match. If it's our first remember it */ + if (rv == SECWouldBlock) { + if (possibleResult.data) { + /* this is unlikely but possible. If we hit this condition, + * we have no way of knowing which possibility to prefer. + * in this case we just match the key the application + * thought was the right one */ + SECITEM_ZfreeItem(result, PR_FALSE); + } else { + possibleResult = *result; + } + } + } + + /* free the list */ + for (testKey = keyList; testKey; testKey = nextKey) { + nextKey = PK11_GetNextSymKey(testKey); + PK11_FreeSymKey(testKey); + } + } + + /* we didn't find a better key, use the one with a small pad value */ + if ((rv != SECSuccess) && (possibleResult.data)) { + *result = possibleResult; + possibleResult.data = NULL; + rv = SECSuccess; + } + +loser: + if (arena) + PORT_FreeArena(arena, PR_TRUE); + if (key) + PK11_FreeSymKey(key); + if (params) + SECITEM_ZfreeItem(params, PR_TRUE); + if (slot) + PK11_FreeSlot(slot); + if (possibleResult.data) + SECITEM_ZfreeItem(&possibleResult, PR_FALSE); + + return rv; +} |