derenc.c
上传用户:lyxiangda
上传日期:2007-01-12
资源大小:3042k
文件大小:13k
- /*
- * 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 Netscape are
- * Copyright (C) 1994-2000 Netscape Communications Corporation. All
- * Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the
- * terms of the GNU General Public License Version 2 or later (the
- * "GPL"), in which case the provisions of the GPL are applicable
- * instead of those above. If you wish to allow use of your
- * version of this file only under the terms of the GPL and not to
- * allow others to use your version of this file under the MPL,
- * indicate your decision by deleting the provisions above and
- * replace them with the notice and other provisions required by
- * the GPL. If you do not delete the provisions above, a recipient
- * may use your version of this file under either the MPL or the
- * GPL.
- */
- #include "secder.h"
- #include "secerr.h"
- /*
- * Generic templates for individual/simple items.
- */
- DERTemplate SECAnyTemplate[] = {
- { DER_ANY,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECBitStringTemplate[] = {
- { DER_BIT_STRING,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECBooleanTemplate[] = {
- { DER_BOOLEAN,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECIA5StringTemplate[] = {
- { DER_IA5_STRING,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECIntegerTemplate[] = {
- { DER_INTEGER,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECNullTemplate[] = {
- { DER_NULL,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECObjectIDTemplate[] = {
- { DER_OBJECT_ID,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECOctetStringTemplate[] = {
- { DER_OCTET_STRING,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECPrintableStringTemplate[] = {
- { DER_PRINTABLE_STRING,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECT61StringTemplate[] = {
- { DER_T61_STRING,
- 0, NULL, sizeof(SECItem) }
- };
- DERTemplate SECUTCTimeTemplate[] = {
- { DER_UTC_TIME,
- 0, NULL, sizeof(SECItem) }
- };
- static int
- header_length(DERTemplate *dtemplate, uint32 contents_len)
- {
- uint32 len;
- unsigned long encode_kind, under_kind;
- PRBool explicit, optional, universal;
- encode_kind = dtemplate->kind;
- explicit = (encode_kind & DER_EXPLICIT) ? PR_TRUE : PR_FALSE;
- optional = (encode_kind & DER_OPTIONAL) ? PR_TRUE : PR_FALSE;
- universal = ((encode_kind & DER_CLASS_MASK) == DER_UNIVERSAL)
- ? PR_TRUE : PR_FALSE;
- PORT_Assert (!(explicit && universal)); /* bad templates */
- if (encode_kind & DER_POINTER) {
- if (dtemplate->sub != NULL) {
- under_kind = dtemplate->sub->kind;
- if (universal) {
- encode_kind = under_kind;
- }
- } else if (universal) {
- under_kind = encode_kind & ~DER_POINTER;
- } else {
- under_kind = dtemplate->arg;
- }
- } else if (encode_kind & DER_INLINE) {
- under_kind = dtemplate->sub->kind;
- if (universal) {
- encode_kind = under_kind;
- }
- } else if (universal) {
- under_kind = encode_kind;
- } else {
- under_kind = dtemplate->arg;
- }
- /* This is only used in decoding; it plays no part in encoding. */
- if (under_kind & DER_DERPTR)
- return 0;
- /* No header at all for an "empty" optional. */
- if ((contents_len == 0) && optional)
- return 0;
- /* And no header for a full DER_ANY. */
- if (encode_kind & DER_ANY)
- return 0;
- /*
- * The common case: one octet for identifier and as many octets
- * as necessary to hold the content length.
- */
- len = 1 + DER_LengthLength(contents_len);
- /* Account for the explicit wrapper, if necessary. */
- if (explicit) {
- #if 0 /*
- * Well, I was trying to do something useful, but these
- * assertions are too restrictive on valid templates.
- * I wanted to make sure that the top-level "kind" of
- * a template does not also specify DER_EXPLICIT, which
- * should only modify a component field. Maybe later
- * I can figure out a better way to detect such a problem,
- * but for now I must remove these checks altogether.
- */
- /*
- * This modifier applies only to components of a set or sequence;
- * it should never be used on a set/sequence itself -- confirm.
- */
- PORT_Assert (under_kind != DER_SEQUENCE);
- PORT_Assert (under_kind != DER_SET);
- #endif
- len += 1 + DER_LengthLength(len + contents_len);
- }
- return len;
- }
- static uint32
- contents_length(DERTemplate *dtemplate, void *src)
- {
- uint32 len;
- unsigned long encode_kind, under_kind;
- PRBool universal;
- PORT_Assert (src != NULL);
- encode_kind = dtemplate->kind;
- universal = ((encode_kind & DER_CLASS_MASK) == DER_UNIVERSAL)
- ? PR_TRUE : PR_FALSE;
- encode_kind &= ~DER_OPTIONAL;
- if (encode_kind & DER_POINTER) {
- src = *(void **)src;
- if (src == NULL) {
- return 0;
- }
- if (dtemplate->sub != NULL) {
- dtemplate = dtemplate->sub;
- under_kind = dtemplate->kind;
- src = (void *)((char *)src + dtemplate->offset);
- } else if (universal) {
- under_kind = encode_kind & ~DER_POINTER;
- } else {
- under_kind = dtemplate->arg;
- }
- } else if (encode_kind & DER_INLINE) {
- PORT_Assert (dtemplate->sub != NULL);
- dtemplate = dtemplate->sub;
- under_kind = dtemplate->kind;
- src = (void *)((char *)src + dtemplate->offset);
- } else if (universal) {
- under_kind = encode_kind;
- } else {
- under_kind = dtemplate->arg;
- }
- /* Having any of these bits is not expected here... */
- PORT_Assert ((under_kind & (DER_EXPLICIT | DER_INLINE | DER_OPTIONAL
- | DER_POINTER | DER_SKIP)) == 0);
- /* This is only used in decoding; it plays no part in encoding. */
- if (under_kind & DER_DERPTR)
- return 0;
- if (under_kind & DER_INDEFINITE) {
- uint32 sub_len;
- void **indp;
- indp = *(void ***)src;
- if (indp == NULL)
- return 0;
- len = 0;
- under_kind &= ~DER_INDEFINITE;
- if (under_kind == DER_SET || under_kind == DER_SEQUENCE) {
- DERTemplate *tmpt;
- void *sub_src;
- tmpt = dtemplate->sub;
- for (; *indp != NULL; indp++) {
- sub_src = (void *)((char *)(*indp) + tmpt->offset);
- sub_len = contents_length (tmpt, sub_src);
- len += sub_len + header_length (tmpt, sub_len);
- }
- } else {
- /*
- * XXX Lisa is not sure this code (for handling, for example,
- * DER_INDEFINITE | DER_OCTET_STRING) is right.
- */
- for (; *indp != NULL; indp++) {
- SECItem *item;
- item = (SECItem *)(*indp);
- sub_len = item->len;
- if (under_kind == DER_BIT_STRING) {
- sub_len = (sub_len + 7) >> 3;
- /* bit string contents involve an extra octet */
- if (sub_len)
- sub_len++;
- }
- if (under_kind != DER_ANY)
- len += 1 + DER_LengthLength (sub_len);
- }
- }
- return len;
- }
- switch (under_kind) {
- case DER_SEQUENCE:
- case DER_SET:
- {
- DERTemplate *tmpt;
- void *sub_src;
- uint32 sub_len;
- len = 0;
- for (tmpt = dtemplate + 1; tmpt->kind; tmpt++) {
- sub_src = (void *)((char *)src + tmpt->offset);
- sub_len = contents_length (tmpt, sub_src);
- len += sub_len + header_length (tmpt, sub_len);
- }
- }
- break;
- case DER_BIT_STRING:
- len = (((SECItem *)src)->len + 7) >> 3;
- /* bit string contents involve an extra octet */
- if (len)
- len++;
- break;
- default:
- len = ((SECItem *)src)->len;
- break;
- }
- return len;
- }
- static unsigned char *
- der_encode(unsigned char *buf, DERTemplate *dtemplate, void *src)
- {
- int header_len;
- uint32 contents_len;
- unsigned long encode_kind, under_kind;
- PRBool explicit, optional, universal;
- /*
- * First figure out how long the encoding will be. Do this by
- * traversing the template from top to bottom and accumulating
- * the length of each leaf item.
- */
- contents_len = contents_length (dtemplate, src);
- header_len = header_length (dtemplate, contents_len);
- /*
- * Enough smarts was involved already, so that if both the
- * header and the contents have a length of zero, then we
- * are not doing any encoding for this element.
- */
- if (header_len == 0 && contents_len == 0)
- return buf;
- encode_kind = dtemplate->kind;
- explicit = (encode_kind & DER_EXPLICIT) ? PR_TRUE : PR_FALSE;
- optional = (encode_kind & DER_OPTIONAL) ? PR_TRUE : PR_FALSE;
- encode_kind &= ~DER_OPTIONAL;
- universal = ((encode_kind & DER_CLASS_MASK) == DER_UNIVERSAL)
- ? PR_TRUE : PR_FALSE;
- if (encode_kind & DER_POINTER) {
- if (contents_len) {
- src = *(void **)src;
- PORT_Assert (src != NULL);
- }
- if (dtemplate->sub != NULL) {
- dtemplate = dtemplate->sub;
- under_kind = dtemplate->kind;
- if (universal) {
- encode_kind = under_kind;
- }
- src = (void *)((char *)src + dtemplate->offset);
- } else if (universal) {
- under_kind = encode_kind & ~DER_POINTER;
- } else {
- under_kind = dtemplate->arg;
- }
- } else if (encode_kind & DER_INLINE) {
- dtemplate = dtemplate->sub;
- under_kind = dtemplate->kind;
- if (universal) {
- encode_kind = under_kind;
- }
- src = (void *)((char *)src + dtemplate->offset);
- } else if (universal) {
- under_kind = encode_kind;
- } else {
- under_kind = dtemplate->arg;
- }
- if (explicit) {
- buf = DER_StoreHeader (buf, encode_kind,
- (1 + DER_LengthLength(contents_len)
- + contents_len));
- encode_kind = under_kind;
- }
- if ((encode_kind & DER_ANY) == 0) { /* DER_ANY already contains header */
- buf = DER_StoreHeader (buf, encode_kind, contents_len);
- }
- /* If no real contents to encode, then we are done. */
- if (contents_len == 0)
- return buf;
- if (under_kind & DER_INDEFINITE) {
- void **indp;
- indp = *(void ***)src;
- PORT_Assert (indp != NULL);
- under_kind &= ~DER_INDEFINITE;
- if (under_kind == DER_SET || under_kind == DER_SEQUENCE) {
- DERTemplate *tmpt;
- void *sub_src;
- tmpt = dtemplate->sub;
- for (; *indp != NULL; indp++) {
- sub_src = (void *)((char *)(*indp) + tmpt->offset);
- buf = der_encode (buf, tmpt, sub_src);
- }
- } else {
- for (; *indp != NULL; indp++) {
- SECItem *item;
- int sub_len;
- item = (SECItem *)(*indp);
- sub_len = item->len;
- if (under_kind == DER_BIT_STRING) {
- if (sub_len) {
- int rem;
- sub_len = (sub_len + 7) >> 3;
- buf = DER_StoreHeader (buf, under_kind, sub_len + 1);
- rem = (sub_len << 3) - item->len;
- *buf++ = rem; /* remaining bits */
- } else {
- buf = DER_StoreHeader (buf, under_kind, 0);
- }
- } else if (under_kind != DER_ANY) {
- buf = DER_StoreHeader (buf, under_kind, sub_len);
- }
- PORT_Memcpy (buf, item->data, sub_len);
- buf += sub_len;
- }
- }
- return buf;
- }
- switch (under_kind) {
- case DER_SEQUENCE:
- case DER_SET:
- {
- DERTemplate *tmpt;
- void *sub_src;
- for (tmpt = dtemplate + 1; tmpt->kind; tmpt++) {
- sub_src = (void *)((char *)src + tmpt->offset);
- buf = der_encode (buf, tmpt, sub_src);
- }
- }
- break;
- case DER_BIT_STRING:
- {
- SECItem *item;
- int rem;
- /*
- * The contents length includes our extra octet; subtract
- * it off so we just have the real string length there.
- */
- contents_len--;
- item = (SECItem *)src;
- PORT_Assert (contents_len == ((item->len + 7) >> 3));
- rem = (contents_len << 3) - item->len;
- *buf++ = rem; /* remaining bits */
- PORT_Memcpy (buf, item->data, contents_len);
- buf += contents_len;
- }
- break;
- default:
- {
- SECItem *item;
- item = (SECItem *)src;
- PORT_Assert (contents_len == item->len);
- PORT_Memcpy (buf, item->data, contents_len);
- buf += contents_len;
- }
- break;
- }
- return buf;
- }
- SECStatus
- DER_Encode(PRArenaPool *arena, SECItem *dest, DERTemplate *dtemplate, void *src)
- {
- unsigned int contents_len, header_len;
- src = (void **)((char *)src + dtemplate->offset);
- /*
- * First figure out how long the encoding will be. Do this by
- * traversing the template from top to bottom and accumulating
- * the length of each leaf item.
- */
- contents_len = contents_length (dtemplate, src);
- header_len = header_length (dtemplate, contents_len);
- dest->len = contents_len + header_len;
- /* Allocate storage to hold the encoding */
- dest->data = (unsigned char*) PORT_ArenaAlloc(arena, dest->len);
- if (dest->data == NULL) {
- PORT_SetError(SEC_ERROR_NO_MEMORY);
- return SECFailure;
- }
- /* Now encode into the buffer */
- (void) der_encode (dest->data, dtemplate, src);
- return SECSuccess;
- }