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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /security/nss/lib/smime/cmscipher.c
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'security/nss/lib/smime/cmscipher.c')
-rw-r--r--security/nss/lib/smime/cmscipher.c722
1 files changed, 722 insertions, 0 deletions
diff --git a/security/nss/lib/smime/cmscipher.c b/security/nss/lib/smime/cmscipher.c
new file mode 100644
index 000000000..9c8330b23
--- /dev/null
+++ b/security/nss/lib/smime/cmscipher.c
@@ -0,0 +1,722 @@
+/* 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/. */
+
+/*
+ * Encryption/decryption routines for CMS implementation, none of which are exported.
+ */
+
+#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;
+ PK11SlotInfo *slot;
+ SECOidTag algtag;
+ SECItem *param = NULL;
+
+ 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, &param, pwitem);
+ if (cryptoMechType == CKM_INVALID_MECHANISM) {
+ SECITEM_FreeItem(param, PR_TRUE);
+ 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(PLArenaPool *poolp, PK11SymKey *key, SECAlgorithmID *algid)
+{
+ NSSCMSCipherContext *cc;
+ void *ciphercx = NULL;
+ SECStatus rv;
+ CK_MECHANISM_TYPE cryptoMechType;
+ PK11SlotInfo *slot;
+ SECItem *param = NULL;
+ 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, &param, pwitem);
+ if (cryptoMechType == CKM_INVALID_MECHANISM) {
+ SECITEM_FreeItem(param, PR_TRUE);
+ 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;
+ ciphercx = NULL;
+ 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);
+ if (ciphercx) {
+ PK11_DestroyContext(ciphercx, 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)
+{
+ unsigned 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) {
+ if (padsize <= 0) {
+ padlen = 0;
+ } else {
+ 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;
+}