diff options
Diffstat (limited to 'security/nss/lib/smime/cmscipher.c')
| -rw-r--r-- | security/nss/lib/smime/cmscipher.c | 747 |
1 files changed, 0 insertions, 747 deletions
diff --git a/security/nss/lib/smime/cmscipher.c b/security/nss/lib/smime/cmscipher.c deleted file mode 100644 index ca9f31d21..000000000 --- a/security/nss/lib/smime/cmscipher.c +++ /dev/null @@ -1,747 +0,0 @@ -/* ***** BEGIN LICENSE BLOCK ***** - * Version: MPL 1.1/GPL 2.0/LGPL 2.1 - * - * The contents of this file are subject to the Mozilla Public License Version - * 1.1 (the "License"); you may not use this file except in compliance with - * the License. You may obtain a copy of the License at - * http://www.mozilla.org/MPL/ - * - * Software distributed under the License is distributed on an "AS IS" basis, - * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License - * for the specific language governing rights and limitations under the - * License. - * - * The Original Code is the Netscape security libraries. - * - * The Initial Developer of the Original Code is - * Netscape Communications Corporation. - * Portions created by the Initial Developer are Copyright (C) 1994-2000 - * the Initial Developer. All Rights Reserved. - * - * Contributor(s): - * - * Alternatively, the contents of this file may be used under the terms of - * either the GNU General Public License Version 2 or later (the "GPL"), or - * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), - * in which case the provisions of the GPL or the LGPL are applicable instead - * of those above. If you wish to allow use of your version of this file only - * under the terms of either the GPL or the LGPL, and not to allow others to - * use your version of this file under the terms of the MPL, indicate your - * decision by deleting the provisions above and replace them with the notice - * and other provisions required by the GPL or the LGPL. If you do not delete - * the provisions above, a recipient may use your version of this file under - * the terms of any one of the MPL, the GPL or the LGPL. - * - * ***** END LICENSE BLOCK ***** */ - -/* - * Encryption/decryption routines for CMS implementation, none of which are exported. - * - * $Id$ - */ - -#include "cmslocal.h" - -#include "secoid.h" -#include "secitem.h" -#include "pk11func.h" -#include "secerr.h" -#include "secpkcs5.h" - -/* - * ------------------------------------------------------------------- - * Cipher stuff. - */ - -typedef SECStatus (*nss_cms_cipher_function) (void *, unsigned char *, unsigned int *, - unsigned int, const unsigned char *, unsigned int); -typedef SECStatus (*nss_cms_cipher_destroy) (void *, PRBool); - -#define BLOCK_SIZE 4096 - -struct NSSCMSCipherContextStr { - void * cx; /* PK11 cipher context */ - nss_cms_cipher_function doit; - nss_cms_cipher_destroy destroy; - PRBool encrypt; /* encrypt / decrypt switch */ - int block_size; /* block & pad sizes for cipher */ - int pad_size; - int pending_count; /* pending data (not yet en/decrypted */ - unsigned char pending_buf[BLOCK_SIZE];/* because of blocking */ -}; - -/* - * NSS_CMSCipherContext_StartDecrypt - create a cipher context to do decryption - * based on the given bulk encryption key and algorithm identifier (which - * may include an iv). - * - * XXX Once both are working, it might be nice to combine this and the - * function below (for starting up encryption) into one routine, and just - * have two simple cover functions which call it. - */ -NSSCMSCipherContext * -NSS_CMSCipherContext_StartDecrypt(PK11SymKey *key, SECAlgorithmID *algid) -{ - NSSCMSCipherContext *cc; - void *ciphercx; - CK_MECHANISM_TYPE cryptoMechType; - SECItem *param; - PK11SlotInfo *slot; - SECOidTag algtag; - - algtag = SECOID_GetAlgorithmTag(algid); - - /* set param and mechanism */ - if (SEC_PKCS5IsAlgorithmPBEAlg(algid)) { - SECItem *pwitem; - - pwitem = PK11_GetSymKeyUserData(key); - if (!pwitem) - return NULL; - - cryptoMechType = PK11_GetPBECryptoMechanism(algid, ¶m, pwitem); - if (cryptoMechType == CKM_INVALID_MECHANISM) { - return NULL; - } - - } else { - cryptoMechType = PK11_AlgtagToMechanism(algtag); - if ((param = PK11_ParamFromAlgid(algid)) == NULL) - return NULL; - } - - cc = (NSSCMSCipherContext *)PORT_ZAlloc(sizeof(NSSCMSCipherContext)); - if (cc == NULL) { - SECITEM_FreeItem(param,PR_TRUE); - return NULL; - } - - /* figure out pad and block sizes */ - cc->pad_size = PK11_GetBlockSize(cryptoMechType, param); - slot = PK11_GetSlotFromKey(key); - cc->block_size = PK11_IsHW(slot) ? BLOCK_SIZE : cc->pad_size; - PK11_FreeSlot(slot); - - /* create PK11 cipher context */ - ciphercx = PK11_CreateContextBySymKey(cryptoMechType, CKA_DECRYPT, - key, param); - SECITEM_FreeItem(param, PR_TRUE); - if (ciphercx == NULL) { - PORT_Free (cc); - return NULL; - } - - cc->cx = ciphercx; - cc->doit = (nss_cms_cipher_function) PK11_CipherOp; - cc->destroy = (nss_cms_cipher_destroy) PK11_DestroyContext; - cc->encrypt = PR_FALSE; - cc->pending_count = 0; - - return cc; -} - -/* - * NSS_CMSCipherContext_StartEncrypt - create a cipher object to do encryption, - * based on the given bulk encryption key and algorithm tag. Fill in the - * algorithm identifier (which may include an iv) appropriately. - * - * XXX Once both are working, it might be nice to combine this and the - * function above (for starting up decryption) into one routine, and just - * have two simple cover functions which call it. - */ -NSSCMSCipherContext * -NSS_CMSCipherContext_StartEncrypt(PRArenaPool *poolp, PK11SymKey *key, SECAlgorithmID *algid) -{ - NSSCMSCipherContext *cc; - void *ciphercx; - SECItem *param; - SECStatus rv; - CK_MECHANISM_TYPE cryptoMechType; - PK11SlotInfo *slot; - PRBool needToEncodeAlgid = PR_FALSE; - SECOidTag algtag = SECOID_GetAlgorithmTag(algid); - - /* set param and mechanism */ - if (SEC_PKCS5IsAlgorithmPBEAlg(algid)) { - SECItem *pwitem; - - pwitem = PK11_GetSymKeyUserData(key); - if (!pwitem) - return NULL; - - cryptoMechType = PK11_GetPBECryptoMechanism(algid, ¶m, pwitem); - if (cryptoMechType == CKM_INVALID_MECHANISM) { - return NULL; - } - } else { - cryptoMechType = PK11_AlgtagToMechanism(algtag); - if ((param = PK11_GenerateNewParam(cryptoMechType, key)) == NULL) - return NULL; - needToEncodeAlgid = PR_TRUE; - } - - cc = (NSSCMSCipherContext *)PORT_ZAlloc(sizeof(NSSCMSCipherContext)); - if (cc == NULL) { - goto loser; - } - - /* now find pad and block sizes for our mechanism */ - cc->pad_size = PK11_GetBlockSize(cryptoMechType, param); - slot = PK11_GetSlotFromKey(key); - cc->block_size = PK11_IsHW(slot) ? BLOCK_SIZE : cc->pad_size; - PK11_FreeSlot(slot); - - /* and here we go, creating a PK11 cipher context */ - ciphercx = PK11_CreateContextBySymKey(cryptoMechType, CKA_ENCRYPT, - key, param); - if (ciphercx == NULL) { - PORT_Free(cc); - cc = NULL; - goto loser; - } - - /* - * These are placed after the CreateContextBySymKey() because some - * mechanisms have to generate their IVs from their card (i.e. FORTEZZA). - * Don't move it from here. - * XXX is that right? the purpose of this is to get the correct algid - * containing the IVs etc. for encoding. this means we need to set this up - * BEFORE encoding the algid in the contentInfo, right? - */ - if (needToEncodeAlgid) { - rv = PK11_ParamToAlgid(algtag, param, poolp, algid); - if(rv != SECSuccess) { - PORT_Free(cc); - cc = NULL; - goto loser; - } - } - - cc->cx = ciphercx; - cc->doit = (nss_cms_cipher_function)PK11_CipherOp; - cc->destroy = (nss_cms_cipher_destroy)PK11_DestroyContext; - cc->encrypt = PR_TRUE; - cc->pending_count = 0; - -loser: - SECITEM_FreeItem(param, PR_TRUE); - - return cc; -} - -void -NSS_CMSCipherContext_Destroy(NSSCMSCipherContext *cc) -{ - PORT_Assert(cc != NULL); - if (cc == NULL) - return; - (*cc->destroy)(cc->cx, PR_TRUE); - PORT_Free(cc); -} - -/* - * NSS_CMSCipherContext_DecryptLength - find the output length of the next call to decrypt. - * - * cc - the cipher context - * input_len - number of bytes used as input - * final - true if this is the final chunk of data - * - * Result can be used to perform memory allocations. Note that the amount - * is exactly accurate only when not doing a block cipher or when final - * is false, otherwise it is an upper bound on the amount because until - * we see the data we do not know how many padding bytes there are - * (always between 1 and bsize). - * - * Note that this can return zero, which does not mean that the decrypt - * operation can be skipped! (It simply means that there are not enough - * bytes to make up an entire block; the bytes will be reserved until - * there are enough to encrypt/decrypt at least one block.) However, - * if zero is returned it *does* mean that no output buffer need be - * passed in to the subsequent decrypt operation, as no output bytes - * will be stored. - */ -unsigned int -NSS_CMSCipherContext_DecryptLength(NSSCMSCipherContext *cc, unsigned int input_len, PRBool final) -{ - int blocks, block_size; - - PORT_Assert (! cc->encrypt); - - block_size = cc->block_size; - - /* - * If this is not a block cipher, then we always have the same - * number of output bytes as we had input bytes. - */ - if (block_size == 0) - return input_len; - - /* - * On the final call, we will always use up all of the pending - * bytes plus all of the input bytes, *but*, there will be padding - * at the end and we cannot predict how many bytes of padding we - * will end up removing. The amount given here is actually known - * to be at least 1 byte too long (because we know we will have - * at least 1 byte of padding), but seemed clearer/better to me. - */ - if (final) - return cc->pending_count + input_len; - - /* - * Okay, this amount is exactly what we will output on the - * next cipher operation. We will always hang onto the last - * 1 - block_size bytes for non-final operations. That is, - * we will do as many complete blocks as we can *except* the - * last block (complete or partial). (This is because until - * we know we are at the end, we cannot know when to interpret - * and removing the padding byte(s), which are guaranteed to - * be there.) - */ - blocks = (cc->pending_count + input_len - 1) / block_size; - return blocks * block_size; -} - -/* - * NSS_CMSCipherContext_EncryptLength - find the output length of the next call to encrypt. - * - * cc - the cipher context - * input_len - number of bytes used as input - * final - true if this is the final chunk of data - * - * Result can be used to perform memory allocations. - * - * Note that this can return zero, which does not mean that the encrypt - * operation can be skipped! (It simply means that there are not enough - * bytes to make up an entire block; the bytes will be reserved until - * there are enough to encrypt/decrypt at least one block.) However, - * if zero is returned it *does* mean that no output buffer need be - * passed in to the subsequent encrypt operation, as no output bytes - * will be stored. - */ -unsigned int -NSS_CMSCipherContext_EncryptLength(NSSCMSCipherContext *cc, unsigned int input_len, PRBool final) -{ - int blocks, block_size; - int pad_size; - - PORT_Assert (cc->encrypt); - - block_size = cc->block_size; - pad_size = cc->pad_size; - - /* - * If this is not a block cipher, then we always have the same - * number of output bytes as we had input bytes. - */ - if (block_size == 0) - return input_len; - - /* - * On the final call, we only send out what we need for - * remaining bytes plus the padding. (There is always padding, - * so even if we have an exact number of blocks as input, we - * will add another full block that is just padding.) - */ - if (final) { - if (pad_size == 0) { - return cc->pending_count + input_len; - } else { - blocks = (cc->pending_count + input_len) / pad_size; - blocks++; - return blocks*pad_size; - } - } - - /* - * Now, count the number of complete blocks of data we have. - */ - blocks = (cc->pending_count + input_len) / block_size; - - - return blocks * block_size; -} - - -/* - * NSS_CMSCipherContext_Decrypt - do the decryption - * - * cc - the cipher context - * output - buffer for decrypted result bytes - * output_len_p - number of bytes in output - * max_output_len - upper bound on bytes to put into output - * input - pointer to input bytes - * input_len - number of input bytes - * final - true if this is the final chunk of data - * - * Decrypts a given length of input buffer (starting at "input" and - * containing "input_len" bytes), placing the decrypted bytes in - * "output" and storing the output length in "*output_len_p". - * "cc" is the return value from NSS_CMSCipher_StartDecrypt. - * When "final" is true, this is the last of the data to be decrypted. - * - * This is much more complicated than it sounds when the cipher is - * a block-type, meaning that the decryption function will only - * operate on whole blocks. But our caller is operating stream-wise, - * and can pass in any number of bytes. So we need to keep track - * of block boundaries. We save excess bytes between calls in "cc". - * We also need to determine which bytes are padding, and remove - * them from the output. We can only do this step when we know we - * have the final block of data. PKCS #7 specifies that the padding - * used for a block cipher is a string of bytes, each of whose value is - * the same as the length of the padding, and that all data is padded. - * (Even data that starts out with an exact multiple of blocks gets - * added to it another block, all of which is padding.) - */ -SECStatus -NSS_CMSCipherContext_Decrypt(NSSCMSCipherContext *cc, unsigned char *output, - unsigned int *output_len_p, unsigned int max_output_len, - const unsigned char *input, unsigned int input_len, - PRBool final) -{ - int blocks, bsize, pcount, padsize; - unsigned int max_needed, ifraglen, ofraglen, output_len; - unsigned char *pbuf; - SECStatus rv; - - PORT_Assert (! cc->encrypt); - - /* - * Check that we have enough room for the output. Our caller should - * already handle this; failure is really an internal error (i.e. bug). - */ - max_needed = NSS_CMSCipherContext_DecryptLength(cc, input_len, final); - PORT_Assert (max_output_len >= max_needed); - if (max_output_len < max_needed) { - /* PORT_SetError (XXX); */ - return SECFailure; - } - - /* - * hardware encryption does not like small decryption sizes here, so we - * allow both blocking and padding. - */ - bsize = cc->block_size; - padsize = cc->pad_size; - - /* - * When no blocking or padding work to do, we can simply call the - * cipher function and we are done. - */ - if (bsize == 0) { - return (* cc->doit) (cc->cx, output, output_len_p, max_output_len, - input, input_len); - } - - pcount = cc->pending_count; - pbuf = cc->pending_buf; - - output_len = 0; - - if (pcount) { - /* - * Try to fill in an entire block, starting with the bytes - * we already have saved away. - */ - while (input_len && pcount < bsize) { - pbuf[pcount++] = *input++; - input_len--; - } - /* - * If we have at most a whole block and this is not our last call, - * then we are done for now. (We do not try to decrypt a lone - * single block because we cannot interpret the padding bytes - * until we know we are handling the very last block of all input.) - */ - if (input_len == 0 && !final) { - cc->pending_count = pcount; - if (output_len_p) - *output_len_p = 0; - return SECSuccess; - } - /* - * Given the logic above, we expect to have a full block by now. - * If we do not, there is something wrong, either with our own - * logic or with (length of) the data given to us. - */ - if ((padsize != 0) && (pcount % padsize) != 0) { - PORT_Assert (final); - PORT_SetError (SEC_ERROR_BAD_DATA); - return SECFailure; - } - /* - * Decrypt the block. - */ - rv = (*cc->doit)(cc->cx, output, &ofraglen, max_output_len, - pbuf, pcount); - if (rv != SECSuccess) - return rv; - - /* - * For now anyway, all of our ciphers have the same number of - * bytes of output as they do input. If this ever becomes untrue, - * then NSS_CMSCipherContext_DecryptLength needs to be made smarter! - */ - PORT_Assert(ofraglen == pcount); - - /* - * Account for the bytes now in output. - */ - max_output_len -= ofraglen; - output_len += ofraglen; - output += ofraglen; - } - - /* - * If this is our last call, we expect to have an exact number of - * blocks left to be decrypted; we will decrypt them all. - * - * If not our last call, we always save between 1 and bsize bytes - * until next time. (We must do this because we cannot be sure - * that none of the decrypted bytes are padding bytes until we - * have at least another whole block of data. You cannot tell by - * looking -- the data could be anything -- you can only tell by - * context, knowing you are looking at the last block.) We could - * decrypt a whole block now but it is easier if we just treat it - * the same way we treat partial block bytes. - */ - if (final) { - if (padsize) { - blocks = input_len / padsize; - ifraglen = blocks * padsize; - } else ifraglen = input_len; - PORT_Assert (ifraglen == input_len); - - if (ifraglen != input_len) { - PORT_SetError(SEC_ERROR_BAD_DATA); - return SECFailure; - } - } else { - blocks = (input_len - 1) / bsize; - ifraglen = blocks * bsize; - PORT_Assert (ifraglen < input_len); - - pcount = input_len - ifraglen; - PORT_Memcpy (pbuf, input + ifraglen, pcount); - cc->pending_count = pcount; - } - - if (ifraglen) { - rv = (* cc->doit)(cc->cx, output, &ofraglen, max_output_len, - input, ifraglen); - if (rv != SECSuccess) - return rv; - - /* - * For now anyway, all of our ciphers have the same number of - * bytes of output as they do input. If this ever becomes untrue, - * then sec_PKCS7DecryptLength needs to be made smarter! - */ - PORT_Assert (ifraglen == ofraglen); - if (ifraglen != ofraglen) { - PORT_SetError(SEC_ERROR_BAD_DATA); - return SECFailure; - } - - output_len += ofraglen; - } else { - ofraglen = 0; - } - - /* - * If we just did our very last block, "remove" the padding by - * adjusting the output length. - */ - if (final && (padsize != 0)) { - unsigned int padlen = *(output + ofraglen - 1); - - if (padlen == 0 || padlen > padsize) { - PORT_SetError(SEC_ERROR_BAD_DATA); - return SECFailure; - } - output_len -= padlen; - } - - PORT_Assert (output_len_p != NULL || output_len == 0); - if (output_len_p != NULL) - *output_len_p = output_len; - - return SECSuccess; -} - -/* - * NSS_CMSCipherContext_Encrypt - do the encryption - * - * cc - the cipher context - * output - buffer for decrypted result bytes - * output_len_p - number of bytes in output - * max_output_len - upper bound on bytes to put into output - * input - pointer to input bytes - * input_len - number of input bytes - * final - true if this is the final chunk of data - * - * Encrypts a given length of input buffer (starting at "input" and - * containing "input_len" bytes), placing the encrypted bytes in - * "output" and storing the output length in "*output_len_p". - * "cc" is the return value from NSS_CMSCipher_StartEncrypt. - * When "final" is true, this is the last of the data to be encrypted. - * - * This is much more complicated than it sounds when the cipher is - * a block-type, meaning that the encryption function will only - * operate on whole blocks. But our caller is operating stream-wise, - * and can pass in any number of bytes. So we need to keep track - * of block boundaries. We save excess bytes between calls in "cc". - * We also need to add padding bytes at the end. PKCS #7 specifies - * that the padding used for a block cipher is a string of bytes, - * each of whose value is the same as the length of the padding, - * and that all data is padded. (Even data that starts out with - * an exact multiple of blocks gets added to it another block, - * all of which is padding.) - * - * XXX I would kind of like to combine this with the function above - * which does decryption, since they have a lot in common. But the - * tricky parts about padding and filling blocks would be much - * harder to read that way, so I left them separate. At least for - * now until it is clear that they are right. - */ -SECStatus -NSS_CMSCipherContext_Encrypt(NSSCMSCipherContext *cc, unsigned char *output, - unsigned int *output_len_p, unsigned int max_output_len, - const unsigned char *input, unsigned int input_len, - PRBool final) -{ - int blocks, bsize, padlen, pcount, padsize; - unsigned int max_needed, ifraglen, ofraglen, output_len; - unsigned char *pbuf; - SECStatus rv; - - PORT_Assert (cc->encrypt); - - /* - * Check that we have enough room for the output. Our caller should - * already handle this; failure is really an internal error (i.e. bug). - */ - max_needed = NSS_CMSCipherContext_EncryptLength (cc, input_len, final); - PORT_Assert (max_output_len >= max_needed); - if (max_output_len < max_needed) { - /* PORT_SetError (XXX); */ - return SECFailure; - } - - bsize = cc->block_size; - padsize = cc->pad_size; - - /* - * When no blocking and padding work to do, we can simply call the - * cipher function and we are done. - */ - if (bsize == 0) { - return (*cc->doit)(cc->cx, output, output_len_p, max_output_len, - input, input_len); - } - - pcount = cc->pending_count; - pbuf = cc->pending_buf; - - output_len = 0; - - if (pcount) { - /* - * Try to fill in an entire block, starting with the bytes - * we already have saved away. - */ - while (input_len && pcount < bsize) { - pbuf[pcount++] = *input++; - input_len--; - } - /* - * If we do not have a full block and we know we will be - * called again, then we are done for now. - */ - if (pcount < bsize && !final) { - cc->pending_count = pcount; - if (output_len_p != NULL) - *output_len_p = 0; - return SECSuccess; - } - /* - * If we have a whole block available, encrypt it. - */ - if ((padsize == 0) || (pcount % padsize) == 0) { - rv = (* cc->doit) (cc->cx, output, &ofraglen, max_output_len, - pbuf, pcount); - if (rv != SECSuccess) - return rv; - - /* - * For now anyway, all of our ciphers have the same number of - * bytes of output as they do input. If this ever becomes untrue, - * then sec_PKCS7EncryptLength needs to be made smarter! - */ - PORT_Assert (ofraglen == pcount); - - /* - * Account for the bytes now in output. - */ - max_output_len -= ofraglen; - output_len += ofraglen; - output += ofraglen; - - pcount = 0; - } - } - - if (input_len) { - PORT_Assert (pcount == 0); - - blocks = input_len / bsize; - ifraglen = blocks * bsize; - - if (ifraglen) { - rv = (* cc->doit) (cc->cx, output, &ofraglen, max_output_len, - input, ifraglen); - if (rv != SECSuccess) - return rv; - - /* - * For now anyway, all of our ciphers have the same number of - * bytes of output as they do input. If this ever becomes untrue, - * then sec_PKCS7EncryptLength needs to be made smarter! - */ - PORT_Assert (ifraglen == ofraglen); - - max_output_len -= ofraglen; - output_len += ofraglen; - output += ofraglen; - } - - pcount = input_len - ifraglen; - PORT_Assert (pcount < bsize); - if (pcount) - PORT_Memcpy (pbuf, input + ifraglen, pcount); - } - - if (final) { - padlen = padsize - (pcount % padsize); - PORT_Memset (pbuf + pcount, padlen, padlen); - rv = (* cc->doit) (cc->cx, output, &ofraglen, max_output_len, - pbuf, pcount+padlen); - if (rv != SECSuccess) - return rv; - - /* - * For now anyway, all of our ciphers have the same number of - * bytes of output as they do input. If this ever becomes untrue, - * then sec_PKCS7EncryptLength needs to be made smarter! - */ - PORT_Assert (ofraglen == (pcount+padlen)); - output_len += ofraglen; - } else { - cc->pending_count = pcount; - } - - PORT_Assert (output_len_p != NULL || output_len == 0); - if (output_len_p != NULL) - *output_len_p = output_len; - - return SECSuccess; -} |