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.. _mozilla_projects_nss_encrypt_decrypt_mac_using_token:
Encrypt and decrypt MAC using token
===================================
.. _nss_sample_code_3_encryptiondecryption_and_mac_using_token_object.:
`NSS sample code 3: encryption/decryption and MAC using token object. <#nss_sample_code_3_encryptiondecryption_and_mac_using_token_object.>`__
----------------------------------------------------------------------------------------------------------------------------------------------
.. container::
Generates encryption/mac keys and uses token for storing.
.. code:: c
/* 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
/* NSPR Headers */
#include
#include
#include
#include
#include
#include
#include
/* NSS headers */
#include
#include
/* our samples utilities */
#include "util.h"
#define BUFFERSIZE 80
#define DIGESTSIZE 16
#define PTEXT_MAC_BUFFER_SIZE 96
#define CIPHERSIZE 96
#define BLOCKSIZE 32
#define CIPHER_HEADER "-----BEGIN CIPHER-----"
#define CIPHER_TRAILER "-----END CIPHER-----"
#define ENCKEY_HEADER "-----BEGIN AESKEY CKAID-----"
#define ENCKEY_TRAILER "-----END AESKEY CKAID-----"
#define MACKEY_HEADER "-----BEGIN MACKEY CKAID-----"
#define MACKEY_TRAILER "-----END MACKEY CKAID-----"
#define IV_HEADER "-----BEGIN IV-----"
#define IV_TRAILER "-----END IV-----"
#define MAC_HEADER "-----BEGIN MAC-----"
#define MAC_TRAILER "-----END MAC-----"
#define PAD_HEADER "-----BEGIN PAD-----"
#define PAD_TRAILER "-----END PAD-----"
typedef enum {
ENCRYPT,
DECRYPT,
UNKNOWN
} CommandType;
typedef enum {
SYMKEY = 0,
MACKEY = 1,
IV = 2,
MAC = 3,
PAD = 4
} HeaderType;
/*
* Print usage message and exit
*/
static void
Usage(const char *progName)
{
fprintf(stderr, "\nUsage: %s -c -d [-z ] "
"[-p | -f ] -i -o \n\n",
progName);
fprintf(stderr, "%-20s Specify 'a' for encrypt operation\n\n",
"-c ");
fprintf(stderr, "%-20s Specify 'b' for decrypt operation\n\n",
" ");
fprintf(stderr, "%-20s Specify db directory path\n\n",
"-d ");
fprintf(stderr, "%-20s Specify db password [optional]\n\n",
"-p ");
fprintf(stderr, "%-20s Specify db password file [optional]\n\n",
"-f ");
fprintf(stderr, "%-20s Specify noise file name [optional]\n\n",
"-z ");
fprintf(stderr, "%-21s Specify an input file name\n\n",
"-i ");
fprintf(stderr, "%-21s Specify an output file name\n\n",
"-o ");
fprintf(stderr, "%-7s For encrypt, it takes as an input file and produces\n",
"Note :");
fprintf(stderr, "%-7s .enc and .header as intermediate output files.\n\n",
"");
fprintf(stderr, "%-7s For decrypt, it takes .enc and .header\n",
"");
fprintf(stderr, "%-7s as input files and produces as a final output file.\n\n",
"");
exit(-1);
}
/*
* Gather a CKA_ID
*/
SECStatus
GatherCKA_ID(PK11SymKey* key, SECItem* buf)
{
SECStatus rv = PK11_ReadRawAttribute(PK11_TypeSymKey, key, CKA_ID, buf);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "PK11_ReadRawAttribute returned (%d)\n", rv);
PR_fprintf(PR_STDERR, "Could not read SymKey CKA_ID attribute\n");
return rv;
}
return rv;
}
/*
* Generate a Symmetric Key
*/
PK11SymKey *
GenerateSYMKey(PK11SlotInfo *slot, CK_MECHANISM_TYPE mechanism,
int keySize, SECItem *keyID, secuPWData *pwdata)
{
SECStatus rv;
PK11SymKey *key;
if (PK11_NeedLogin(slot)) {
rv = PK11_Authenticate(slot, PR_TRUE, pwdata);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Could not authenticate to token %s.\n",
PK11_GetTokenName(slot));
return NULL;
}
}
/* Generate the symmetric key */
key = PK11_TokenKeyGen(slot, mechanism,
NULL, keySize, keyID, PR_TRUE, pwdata);
if (!key) {
PR_fprintf(PR_STDERR, "Symmetric Key Generation Failed \n");
}
return key;
}
/*
* MacInit
*/
SECStatus
MacInit(PK11Context *ctx)
{
SECStatus rv = PK11_DigestBegin(ctx);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Compute MAC Failed : PK11_DigestBegin()\n");
}
return rv;
}
/*
* MacUpdate
*/
SECStatus
MacUpdate(PK11Context *ctx,
unsigned char *msg, unsigned int msgLen)
{
SECStatus rv = PK11_DigestOp(ctx, msg, msgLen);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Compute MAC Failed : DigestOp()\n");
}
return rv;
}
/*
* Finalize MACing
*/
SECStatus
MacFinal(PK11Context *ctx,
unsigned char *mac, unsigned int *macLen, unsigned int maxLen)
{
SECStatus rv = PK11_DigestFinal(ctx, mac, macLen, maxLen);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Compute MAC Failed : PK11_DigestFinal()\n");
}
return SECSuccess;
}
/*
* Compute Mac
*/
SECStatus
ComputeMac(PK11Context *ctxmac,
unsigned char *ptext, unsigned int ptextLen,
unsigned char *mac, unsigned int *macLen,
unsigned int maxLen)
{
SECStatus rv = MacInit(ctxmac);
if (rv != SECSuccess) return rv;
rv = MacUpdate(ctxmac, ptext, ptextLen);
if (rv != SECSuccess) return rv;
rv = MacFinal(ctxmac, mac, macLen, maxLen);
return rv;
}
/*
* WriteToHeaderFile
*/
SECStatus
WriteToHeaderFile(const char *buf, unsigned int len, HeaderType type,
PRFileDesc *outFile)
{
SECStatus rv;
char header[40];
char trailer[40];
char *outString = NULL;
switch (type) {
case SYMKEY:
strcpy(header, ENCKEY_HEADER);
strcpy(trailer, ENCKEY_TRAILER);
break;
case MACKEY:
strcpy(header, MACKEY_HEADER);
strcpy(trailer, MACKEY_TRAILER);
break;
case IV:
strcpy(header, IV_HEADER);
strcpy(trailer, IV_TRAILER);
break;
case MAC:
strcpy(header, MAC_HEADER);
strcpy(trailer, MAC_TRAILER);
break;
case PAD:
strcpy(header, PAD_HEADER);
strcpy(trailer, PAD_TRAILER);
break;
}
PR_fprintf(outFile, "%s\n", header);
PrintAsHex(outFile, buf, len);
PR_fprintf(outFile, "%s\n\n", trailer);
return SECSuccess;
}
/*
* Initialize for encryption or decryption - common code
*/
PK11Context *
CryptInit(PK11SymKey *key,
unsigned char *iv, unsigned int ivLen,
CK_MECHANISM_TYPE type, CK_ATTRIBUTE_TYPE operation)
{
SECItem ivItem = { siBuffer, iv, ivLen };
PK11Context *ctx = NULL;
SECItem *secParam = PK11_ParamFromIV(CKM_AES_CBC, &ivItem);
if (secParam == NULL) {
PR_fprintf(PR_STDERR, "Crypt Failed : secParam NULL\n");
return NULL;
}
ctx = PK11_CreateContextBySymKey(CKM_AES_CBC, operation, key, secParam);
if (ctx == NULL) {
PR_fprintf(PR_STDERR, "Crypt Failed : can't create a context\n");
goto cleanup;
}
cleanup:
if (secParam) {
SECITEM_FreeItem(secParam, PR_TRUE);
}
return ctx;
}
/*
* Common encryption and decryption code
*/
SECStatus
Crypt(PK11Context *ctx,
unsigned char *out, unsigned int *outLen, unsigned int maxOut,
unsigned char *in, unsigned int inLen)
{
SECStatus rv;
rv = PK11_CipherOp(ctx, out, outLen, maxOut, in, inLen);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Crypt Failed : PK11_CipherOp returned %d\n", rv);
goto cleanup;
}
cleanup:
if (rv != SECSuccess) {
return rv;
}
return SECSuccess;
}
/*
* Decrypt
*/
SECStatus
Decrypt(PK11Context *ctx,
unsigned char *out, unsigned int *outLen, unsigned int maxout,
unsigned char *in, unsigned int inLen)
{
return Crypt(ctx, out, outLen, maxout, in, inLen);
}
/*
* Encrypt
*/
SECStatus
Encrypt(PK11Context* ctx,
unsigned char *out, unsigned int *outLen, unsigned int maxout,
unsigned char *in, unsigned int inLen)
{
return Crypt(ctx, out, outLen, maxout, in, inLen);
}
/*
* EncryptInit
*/
PK11Context *
EncryptInit(PK11SymKey *ek, unsigned char *iv, unsigned int ivLen,
CK_MECHANISM_TYPE type)
{
return CryptInit(ek, iv, ivLen, type, CKA_ENCRYPT);
}
/*
* DecryptInit
*/
PK11Context *
DecryptInit(PK11SymKey *dk, unsigned char *iv, unsigned int ivLen,
CK_MECHANISM_TYPE type)
{
return CryptInit(dk, iv, ivLen, type, CKA_DECRYPT);
}
/*
* Read cryptographic parameters from the header file
*/
SECStatus
ReadFromHeaderFile(const char *fileName, HeaderType type,
SECItem *item, PRBool isHexData)
{
SECStatus rv;
PRFileDesc* file;
SECItem filedata;
SECItem outbuf;
unsigned char *nonbody;
unsigned char *body;
char header[40];
char trailer[40];
outbuf.type = siBuffer;
file = PR_Open(fileName, PR_RDONLY, 0);
if (!file) {
PR_fprintf(PR_STDERR, "Failed to open %s\n", fileName);
return SECFailure;
}
switch (type) {
case SYMKEY:
strcpy(header, ENCKEY_HEADER);
strcpy(trailer, ENCKEY_TRAILER);
break;
case MACKEY:
strcpy(header, MACKEY_HEADER);
strcpy(trailer, MACKEY_TRAILER);
break;
case IV:
strcpy(header, IV_HEADER);
strcpy(trailer, IV_TRAILER);
break;
case MAC:
strcpy(header, MAC_HEADER);
strcpy(trailer, MAC_TRAILER);
break;
case PAD:
strcpy(header, PAD_HEADER);
strcpy(trailer, PAD_TRAILER);
break;
}
rv = FileToItem(&filedata, file);
nonbody = (char *)filedata.data;
if (!nonbody) {
PR_fprintf(PR_STDERR, "unable to read data from input file\n");
rv = SECFailure;
goto cleanup;
}
/* check for headers and trailers and remove them */
if ((body = strstr(nonbody, header)) != NULL) {
char *trail = NULL;
nonbody = body;
body = PORT_Strchr(body, '\n');
if (!body)
body = PORT_Strchr(nonbody, '\r'); /* maybe this is a MAC file */
if (body)
trail = strstr(++body, trailer);
if (trail != NULL) {
*trail = '\0';
} else {
PR_fprintf(PR_STDERR, "input has header but no trailer\n");
PORT_Free(filedata.data);
return SECFailure;
}
} else {
body = nonbody;
}
cleanup:
PR_Close(file);
HexToBuf(body, item, isHexData);
return SECSuccess;
}
/*
* EncryptAndMac
*/
SECStatus
EncryptAndMac(PRFileDesc *inFile,
PRFileDesc *headerFile,
PRFileDesc *encFile,
PK11SymKey *ek,
PK11SymKey *mk,
unsigned char *iv, unsigned int ivLen,
PRBool ascii)
{
SECStatus rv;
unsigned char ptext[BLOCKSIZE];
unsigned int ptextLen;
unsigned char mac[DIGESTSIZE];
unsigned int macLen;
unsigned int nwritten;
unsigned char encbuf[BLOCKSIZE];
unsigned int encbufLen;
SECItem noParams = { siBuffer, NULL, 0 };
PK11Context *ctxmac = NULL;
PK11Context *ctxenc = NULL;
unsigned int pad[1];
SECItem padItem;
unsigned int paddingLength;
static unsigned int firstTime = 1;
int j;
ctxmac = PK11_CreateContextBySymKey(CKM_MD5_HMAC, CKA_SIGN, mk, &noParams);
if (ctxmac == NULL) {
PR_fprintf(PR_STDERR, "Can't create MAC context\n");
rv = SECFailure;
goto cleanup;
}
rv = MacInit(ctxmac);
if (rv != SECSuccess) {
goto cleanup;
}
ctxenc = EncryptInit(ek, iv, ivLen, CKM_AES_CBC);
/* read a buffer of plaintext from input file */
while ((ptextLen = PR_Read(inFile, ptext, sizeof(ptext))) > 0) {
/* Encrypt using it using CBC, using previously created IV */
if (ptextLen != BLOCKSIZE) {
paddingLength = BLOCKSIZE - ptextLen;
for ( j=0; j < paddingLength; j++) {
ptext[ptextLen+j] = (unsigned char)paddingLength;
}
ptextLen = BLOCKSIZE;
}
rv = Encrypt(ctxenc,
encbuf, &encbufLen, sizeof(encbuf),
ptext, ptextLen);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Encrypt Failure\n");
goto cleanup;
}
/* save the last block of ciphertext as the next IV */
iv = encbuf;
ivLen = encbufLen;
/* write the cipher text to intermediate file */
nwritten = PR_Write(encFile, encbuf, encbufLen);
/*PR_Assert(nwritten == encbufLen);*/
rv = MacUpdate(ctxmac, ptext, ptextLen);
}
rv = MacFinal(ctxmac, mac, &macLen, DIGESTSIZE);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "MacFinal Failure\n");
goto cleanup;
}
if (macLen == 0) {
PR_fprintf(PR_STDERR, "Bad MAC length\n");
rv = SECFailure;
goto cleanup;
}
WriteToHeaderFile(mac, macLen, MAC, headerFile);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Write MAC Failure\n");
goto cleanup;
}
pad[0] = paddingLength;
padItem.type = siBuffer;
padItem.data = (unsigned char *)pad;
padItem.len = sizeof(pad[0]);
WriteToHeaderFile(padItem.data, padItem.len, PAD, headerFile);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Write PAD Failure\n");
goto cleanup;
}
rv = SECSuccess;
cleanup:
if (ctxmac != NULL) {
PK11_DestroyContext(ctxmac, PR_TRUE);
}
if (ctxenc != NULL) {
PK11_DestroyContext(ctxenc, PR_TRUE);
}
return rv;
}
/*
* Find the Key for the given mechanism
*/
PK11SymKey*
FindKey(PK11SlotInfo *slot,
CK_MECHANISM_TYPE mechanism,
SECItem *keyBuf, secuPWData *pwdata)
{
SECStatus rv;
PK11SymKey *key;
if (PK11_NeedLogin(slot)) {
rv = PK11_Authenticate(slot, PR_TRUE, pwdata);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR,
"Could not authenticate to token %s.\n",
PK11_GetTokenName(slot));
if (slot) {
PK11_FreeSlot(slot);
}
return NULL;
}
}
key = PK11_FindFixedKey(slot, mechanism, keyBuf, 0);
if (!key) {
PR_fprintf(PR_STDERR,
"PK11_FindFixedKey failed (err %d)\n",
PR_GetError());
PK11_FreeSlot(slot);
return NULL;
}
return key;
}
/*
* Decrypt and Verify MAC
*/
SECStatus
DecryptAndVerifyMac(const char* outFileName,
char *encryptedFileName,
SECItem *cItem, SECItem *macItem,
PK11SymKey* ek, PK11SymKey* mk, SECItem *ivItem, SECItem *padItem)
{
SECStatus rv;
PRFileDesc* inFile;
PRFileDesc* outFile;
unsigned char decbuf[64];
unsigned int decbufLen;
unsigned char ptext[BLOCKSIZE];
unsigned int ptextLen = 0;
unsigned char ctext[64];
unsigned int ctextLen;
unsigned char newmac[DIGESTSIZE];
unsigned int newmacLen = 0;
unsigned int newptextLen = 0;
unsigned int count = 0;
unsigned int temp = 0;
unsigned int blockNumber = 0;
SECItem noParams = { siBuffer, NULL, 0 };
PK11Context *ctxmac = NULL;
PK11Context *ctxenc = NULL;
unsigned char iv[BLOCKSIZE];
unsigned int ivLen = ivItem->len;
unsigned int fileLength;
unsigned int paddingLength;
int j;
memcpy(iv, ivItem->data, ivItem->len);
paddingLength = (unsigned int)padItem->data[0];
ctxmac = PK11_CreateContextBySymKey(CKM_MD5_HMAC, CKA_SIGN, mk, &noParams);
if (ctxmac == NULL) {
PR_fprintf(PR_STDERR, "Can't create MAC context\n");
rv = SECFailure;
goto cleanup;
}
/* Open the input file. */
inFile = PR_Open(encryptedFileName, PR_RDONLY , 0);
if (!inFile) {
PR_fprintf(PR_STDERR,
"Unable to open \"%s\" for writing.\n",
encryptedFileName);
return SECFailure;
}
/* Open the output file. */
outFile = PR_Open(outFileName,
PR_CREATE_FILE | PR_TRUNCATE | PR_RDWR , 00660);
if (!outFile) {
PR_fprintf(PR_STDERR,
"Unable to open \"%s\" for writing.\n",
outFileName);
return SECFailure;
}
rv = MacInit(ctxmac);
if (rv != SECSuccess) goto cleanup;
ctxenc = DecryptInit(ek, iv, ivLen, CKM_AES_CBC);
fileLength = FileSize(encryptedFileName);
while ((ctextLen = PR_Read(inFile, ctext, sizeof(ctext))) > 0) {
count += ctextLen;
/* decrypt cipher text buffer using CBC and IV */
rv = Decrypt(ctxenc, decbuf, &decbufLen, sizeof(decbuf),
ctext, ctextLen);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Decrypt Failure\n");
goto cleanup;
}
if (decbufLen == 0) break;
rv = MacUpdate(ctxmac, decbuf, decbufLen);
if (rv != SECSuccess) { goto cleanup; }
if (count == fileLength) {
decbufLen = decbufLen-paddingLength;
}
/* write the plain text to out file */
temp = PR_Write(outFile, decbuf, decbufLen);
if (temp != decbufLen) {
PR_fprintf(PR_STDERR, "write error\n");
rv = SECFailure;
break;
}
/* save last block of ciphertext */
memcpy(iv, decbuf, decbufLen);
ivLen = decbufLen;
blockNumber++;
}
if (rv != SECSuccess) { goto cleanup; }
rv = MacFinal(ctxmac, newmac, &newmacLen, sizeof(newmac));
if (rv != SECSuccess) { goto cleanup; }
if (PORT_Memcmp(macItem->data, newmac, newmacLen) == 0) {
rv = SECSuccess;
} else {
PR_fprintf(PR_STDERR, "Check MAC : Failure\n");
PR_fprintf(PR_STDERR, "Extracted : ");
PrintAsHex(PR_STDERR, macItem->data, macItem->len);
PR_fprintf(PR_STDERR, "Computed : ");
PrintAsHex(PR_STDERR, newmac, newmacLen);
rv = SECFailure;
}
cleanup:
if (ctxmac) {
PK11_DestroyContext(ctxmac, PR_TRUE);
}
if (ctxenc) {
PK11_DestroyContext(ctxenc, PR_TRUE);
}
if (outFile) {
PR_Close(outFile);
}
return rv;
}
/*
* Gets IV and CKAIDS From Header File
*/
SECStatus
GetIVandCKAIDSFromHeader(const char *cipherFileName,
SECItem *ivItem, SECItem *encKeyItem, SECItem *macKeyItem)
{
SECStatus rv;
/* open intermediate file, read in header, get IV and CKA_IDs of two keys
* from it
*/
rv = ReadFromHeaderFile(cipherFileName, IV, ivItem, PR_TRUE);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Could not retrieve IV from cipher file\n");
goto cleanup;
}
rv = ReadFromHeaderFile(cipherFileName, SYMKEY, encKeyItem, PR_TRUE);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR,
"Could not retrieve AES CKA_ID from cipher file\n");
goto cleanup;
}
rv = ReadFromHeaderFile(cipherFileName, MACKEY, macKeyItem, PR_TRUE);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR,
"Could not retrieve MAC CKA_ID from cipher file\n");
goto cleanup;
}
cleanup:
return rv;
}
/*
* DecryptFile
*/
SECStatus
DecryptFile(PK11SlotInfo *slot,
const char *dbdir,
const char *outFileName,
const char *headerFileName,
char *encryptedFileName,
secuPWData *pwdata,
PRBool ascii)
{
/*
* The DB is open read only and we have authenticated to it
* open input file, read in header, get IV and CKA_IDs of two keys from it
* find those keys in the DB token
* Open output file
* loop until EOF(input):
* read a buffer of ciphertext from input file,
* Save last block of ciphertext
* decrypt ciphertext buffer using CBC and IV,
* compute and check MAC, then remove MAC from plaintext
* replace IV with saved last block of ciphertext
* write the plain text to output file
* close files
* report success
*/
SECStatus rv;
SECItem ivItem;
SECItem encKeyItem;
SECItem macKeyItem;
SECItem cipherItem;
SECItem macItem;
SECItem padItem;
PK11SymKey *encKey = NULL;
PK11SymKey *macKey = NULL;
/* open intermediate file, read in header, get IV and CKA_IDs of two keys
* from it
*/
rv = GetIVandCKAIDSFromHeader(headerFileName,
&ivItem, &encKeyItem, &macKeyItem);
if (rv != SECSuccess) {
goto cleanup;
}
/* find those keys in the DB token */
encKey = FindKey(slot, CKM_AES_CBC, &encKeyItem, pwdata);
if (encKey == NULL) {
PR_fprintf(PR_STDERR, "Can't find the encryption key\n");
rv = SECFailure;
goto cleanup;
}
/* CKM_MD5_HMAC or CKM_EXTRACT_KEY_FROM_KEY */
macKey = FindKey(slot, CKM_MD5_HMAC, &macKeyItem, pwdata);
if (macKey == NULL) {
rv = SECFailure;
goto cleanup;
}
/* Read in the Mac into item from the intermediate file */
rv = ReadFromHeaderFile(headerFileName, MAC, &macItem, PR_TRUE);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR,
"Could not retrieve MAC from cipher file\n");
goto cleanup;
}
if (macItem.data == NULL) {
PR_fprintf(PR_STDERR, "MAC has NULL data\n");
rv = SECFailure;
goto cleanup;
}
if (macItem.len == 0) {
PR_fprintf(PR_STDERR, "MAC has data has 0 length\n");
/*rv = SECFailure;
goto cleanup;*/
}
rv = ReadFromHeaderFile(headerFileName, PAD, &padItem, PR_TRUE);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR,
"Could not retrieve PAD detail from header file\n");
goto cleanup;
}
if (rv == SECSuccess) {
/* Decrypt and Remove Mac */
rv = DecryptAndVerifyMac(outFileName, encryptedFileName,
&cipherItem, &macItem, encKey, macKey, &ivItem, &padItem);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Failed while decrypting and removing MAC\n");
}
}
cleanup:
if (slot) {
PK11_FreeSlot(slot);
}
if (encKey) {
PK11_FreeSymKey(encKey);
}
if (macKey) {
PK11_FreeSymKey(macKey);
}
return rv;
}
/*
* EncryptFile
*/
SECStatus
EncryptFile(PK11SlotInfo *slot,
const char *dbdir,
const char *inFileName,
const char *headerFileName,
const char *encryptedFileName,
const char *noiseFileName,
secuPWData *pwdata,
PRBool ascii)
{
/*
* The DB is open for read/write and we have authenticated to it.
* generate a symmetric AES key as a token object.
* generate a second key to use for MACing, also a token object.
* get their CKA_IDs
* generate a random value to use as IV for AES CBC
* open an input file and an output file,
* write a header to the output that identifies the two keys by
* their CKA_IDs, May include original file name and length.
* loop until EOF(input)
* read a buffer of plaintext from input file,
* MAC it, append the MAC to the plaintext
* encrypt it using CBC, using previously created IV,
* store the last block of ciphertext as the new IV,
* write the cipher text to intermediate file
* close files
* report success
*/
SECStatus rv;
PRFileDesc *inFile;
PRFileDesc *headerFile;
PRFileDesc *encFile;
unsigned char *encKeyId = (unsigned char *) "Encrypt Key";
unsigned char *macKeyId = (unsigned char *) "MAC Key";
SECItem encKeyID = { siAsciiString, encKeyId, PL_strlen(encKeyId) };
SECItem macKeyID = { siAsciiString, macKeyId, PL_strlen(macKeyId) };
SECItem encCKAID;
SECItem macCKAID;
unsigned char iv[BLOCKSIZE];
SECItem ivItem;
PK11SymKey *encKey = NULL;
PK11SymKey *macKey = NULL;
SECItem temp;
unsigned char c;
/* generate a symmetric AES key as a token object. */
encKey = GenerateSYMKey(slot, CKM_AES_KEY_GEN, 128/8, &encKeyID, pwdata);
if (encKey == NULL) {
PR_fprintf(PR_STDERR, "GenerateSYMKey for AES returned NULL.\n");
rv = SECFailure;
goto cleanup;
}
/* generate a second key to use for MACing, also a token object. */
macKey = GenerateSYMKey(slot, CKM_GENERIC_SECRET_KEY_GEN, 160/8,
&macKeyID, pwdata);
if (macKey == NULL) {
PR_fprintf(PR_STDERR, "GenerateSYMKey for MACing returned NULL.\n");
rv = SECFailure;
goto cleanup;
}
/* get the encrypt key CKA_ID */
rv = GatherCKA_ID(encKey, &encCKAID);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Error while wrapping encrypt key\n");
goto cleanup;
}
/* get the MAC key CKA_ID */
rv = GatherCKA_ID(macKey, &macCKAID);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Can't get the MAC key CKA_ID.\n");
goto cleanup;
}
if (noiseFileName) {
rv = SeedFromNoiseFile(noiseFileName);
if (rv != SECSuccess) {
PORT_SetError(PR_END_OF_FILE_ERROR);
return SECFailure;
}
rv = PK11_GenerateRandom(iv, BLOCKSIZE);
if (rv != SECSuccess) {
goto cleanup;
}
} else {
/* generate a random value to use as IV for AES CBC */
GenerateRandom(iv, BLOCKSIZE);
}
headerFile = PR_Open(headerFileName,
PR_CREATE_FILE | PR_TRUNCATE | PR_RDWR, 00660);
if (!headerFile) {
PR_fprintf(PR_STDERR,
"Unable to open \"%s\" for writing.\n",
headerFileName);
return SECFailure;
}
encFile = PR_Open(encryptedFileName,
PR_CREATE_FILE | PR_TRUNCATE | PR_RDWR, 00660);
if (!encFile) {
PR_fprintf(PR_STDERR,
"Unable to open \"%s\" for writing.\n",
encryptedFileName);
return SECFailure;
}
/* write to a header file the IV and the CKA_IDs
* identifying the two keys
*/
ivItem.type = siBuffer;
ivItem.data = iv;
ivItem.len = BLOCKSIZE;
rv = WriteToHeaderFile(iv, BLOCKSIZE, IV, headerFile);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Error writing IV to cipher file - %s\n",
headerFileName);
goto cleanup;
}
rv = WriteToHeaderFile(encCKAID.data, encCKAID.len, SYMKEY, headerFile);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Error writing AES CKA_ID to cipher file - %s\n",
encryptedFileName);
goto cleanup;
}
rv = WriteToHeaderFile(macCKAID.data, macCKAID.len, MACKEY, headerFile);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Error writing MAC CKA_ID to cipher file - %s\n",
headerFileName);
goto cleanup;
}
/* Open the input file. */
inFile = PR_Open(inFileName, PR_RDONLY, 0);
if (!inFile) {
PR_fprintf(PR_STDERR, "Unable to open \"%s\" for reading.\n",
inFileName);
return SECFailure;
}
/* Macing and Encryption */
if (rv == SECSuccess) {
rv = EncryptAndMac(inFile, headerFile, encFile,
encKey, macKey, ivItem.data, ivItem.len, ascii);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Failed : Macing and Encryption\n");
goto cleanup;
}
}
cleanup:
if (inFile) {
PR_Close(inFile);
}
if (headerFile) {
PR_Close(headerFile);
}
if (encFile) {
PR_Close(encFile);
}
if (slot) {
PK11_FreeSlot(slot);
}
if (encKey) {
PK11_FreeSymKey(encKey);
}
if (macKey) {
PK11_FreeSymKey(macKey);
}
return rv;
}
/*
* This example illustrates basic encryption/decryption and MACing
* Generates the encryption/mac keys and uses token for storing.
* Encrypts the input file and appends MAC before storing in intermediate
* header file.
* Writes the CKA_IDs of the encryption keys into intermediate header file.
* Reads the intermediate headerfile for CKA_IDs and encrypted
* contents and decrypts into output file.
*/
int
main(int argc, char **argv)
{
SECStatus rv;
SECStatus rvShutdown;
PK11SlotInfo *slot = NULL;
PLOptState *optstate;
PLOptStatus status;
char headerFileName[50];
char encryptedFileName[50];
PRFileDesc *inFile;
PRFileDesc *outFile;
PRBool ascii = PR_FALSE;
CommandType cmd = UNKNOWN;
const char *command = NULL;
const char *dbdir = NULL;
const char *inFileName = NULL;
const char *outFileName = NULL;
const char *noiseFileName = NULL;
secuPWData pwdata = { PW_NONE, 0 };
char * progName = strrchr(argv[0], '/');
progName = progName ? progName + 1 : argv[0];
/* Parse command line arguments */
optstate = PL_CreateOptState(argc, argv, "c:d:i:o:f:p:z:a");
while ((status = PL_GetNextOpt(optstate)) == PL_OPT_OK) {
switch (optstate->option) {
case 'a':
ascii = PR_TRUE;
break;
case 'c':
command = strdup(optstate->value);
break;
case 'd':
dbdir = strdup(optstate->value);
break;
case 'f':
pwdata.source = PW_FROMFILE;
pwdata.data = strdup(optstate->value);
break;
case 'p':
pwdata.source = PW_PLAINTEXT;
pwdata.data = strdup(optstate->value);
break;
case 'i':
inFileName = strdup(optstate->value);
break;
case 'o':
outFileName = strdup(optstate->value);
break;
case 'z':
noiseFileName = strdup(optstate->value);
break;
default:
Usage(progName);
break;
}
}
PL_DestroyOptState(optstate);
if (!command || !dbdir || !inFileName || !outFileName)
Usage(progName);
if (PL_strlen(command)==0)
Usage(progName);
cmd = command[0] == 'a' ? ENCRYPT : command[0] == 'b' ? DECRYPT : UNKNOWN;
/* Open the input file. */
inFile = PR_Open(inFileName, PR_RDONLY, 0);
if (!inFile) {
PR_fprintf(PR_STDERR, "Unable to open \"%s\" for reading.\n",
inFileName);
return SECFailure;
}
PR_Close(inFile);
/* For intermediate header file, choose filename as inputfile name
with extension ".header" */
strcpy(headerFileName, inFileName);
strcat(headerFileName, ".header");
/* For intermediate encrypted file, choose filename as inputfile name
with extension ".enc" */
strcpy(encryptedFileName, inFileName);
strcat(encryptedFileName, ".enc");
PR_Init(PR_USER_THREAD, PR_PRIORITY_NORMAL, 0);
switch (cmd) {
case ENCRYPT:
/* If the intermediate header file already exists, delete it */
if (PR_Access(headerFileName, PR_ACCESS_EXISTS) == PR_SUCCESS) {
PR_Delete(headerFileName);
}
/* If the intermediate encrypted already exists, delete it */
if (PR_Access(encryptedFileName, PR_ACCESS_EXISTS) == PR_SUCCESS) {
PR_Delete(encryptedFileName);
}
/* Open DB for read/write and authenticate to it. */
rv = NSS_InitReadWrite(dbdir);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "NSS_InitReadWrite Failed\n");
goto cleanup;
}
PK11_SetPasswordFunc(GetModulePassword);
slot = PK11_GetInternalKeySlot();
if (PK11_NeedLogin(slot)) {
rv = PK11_Authenticate(slot, PR_TRUE, &pwdata);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Could not authenticate to token %s.\n",
PK11_GetTokenName(slot));
goto cleanup;
}
}
rv = EncryptFile(slot, dbdir,
inFileName, headerFileName, encryptedFileName,
noiseFileName, &pwdata, ascii);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "EncryptFile : Failed\n");
return SECFailure;
}
break;
case DECRYPT:
/* Open DB read only, authenticate to it */
PK11_SetPasswordFunc(GetModulePassword);
rv = NSS_Init(dbdir);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "NSS_Init Failed\n");
return SECFailure;
}
slot = PK11_GetInternalKeySlot();
if (PK11_NeedLogin(slot)) {
rv = PK11_Authenticate(slot, PR_TRUE, &pwdata);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "Could not authenticate to token %s.\n",
PK11_GetTokenName(slot));
goto cleanup;
}
}
rv = DecryptFile(slot, dbdir,
outFileName, headerFileName,
encryptedFileName, &pwdata, ascii);
if (rv != SECSuccess) {
PR_fprintf(PR_STDERR, "DecryptFile : Failed\n");
return SECFailure;
}
break;
}
cleanup:
rvShutdown = NSS_Shutdown();
if (rvShutdown != SECSuccess) {
PR_fprintf(PR_STDERR, "Failed : NSS_Shutdown()\n");
rv = SECFailure;
}
PR_Cleanup();
return rv;
}