diff options
Diffstat (limited to 'mozilla/security/nss/lib/util/derdec.c')
| -rw-r--r-- | mozilla/security/nss/lib/util/derdec.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/mozilla/security/nss/lib/util/derdec.c b/mozilla/security/nss/lib/util/derdec.c new file mode 100644 index 0000000..4faa680 --- /dev/null +++ b/mozilla/security/nss/lib/util/derdec.c @@ -0,0 +1,221 @@ +/* ***** 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 ***** */ + +#include "secder.h" +#include "secerr.h" + +static PRUint32 +der_indefinite_length(unsigned char *buf, unsigned char *end) +{ + PRUint32 len, ret, dataLen; + unsigned char tag, lenCode; + int dataLenLen; + + len = 0; + while ( 1 ) { + if ((buf + 2) > end) { + return(0); + } + + tag = *buf++; + lenCode = *buf++; + len += 2; + + if ( ( tag == 0 ) && ( lenCode == 0 ) ) { + return(len); + } + + if ( lenCode == 0x80 ) { /* indefinite length */ + ret = der_indefinite_length(buf, end); /* recurse to find length */ + if (ret == 0) + return 0; + len += ret; + buf += ret; + } else { /* definite length */ + if (lenCode & 0x80) { + /* Length of data is in multibyte format */ + dataLenLen = lenCode & 0x7f; + switch (dataLenLen) { + case 1: + dataLen = buf[0]; + break; + case 2: + dataLen = (buf[0]<<8)|buf[1]; + break; + case 3: + dataLen = ((unsigned long)buf[0]<<16)|(buf[1]<<8)|buf[2]; + break; + case 4: + dataLen = ((unsigned long)buf[0]<<24)| + ((unsigned long)buf[1]<<16)|(buf[2]<<8)|buf[3]; + break; + default: + PORT_SetError(SEC_ERROR_BAD_DER); + return SECFailure; + } + } else { + /* Length of data is in single byte */ + dataLen = lenCode; + dataLenLen = 0; + } + + /* skip this item */ + buf = buf + dataLenLen + dataLen; + len = len + dataLenLen + dataLen; + } + } +} + +/* +** Capture the next thing in the buffer. +** Returns the length of the header and the length of the contents. +*/ +static SECStatus +der_capture(unsigned char *buf, unsigned char *end, + int *header_len_p, PRUint32 *contents_len_p) +{ + unsigned char *bp; + unsigned char whole_tag; + PRUint32 contents_len; + int tag_number; + + if ((buf + 2) > end) { + *header_len_p = 0; + *contents_len_p = 0; + if (buf == end) + return SECSuccess; + return SECFailure; + } + + bp = buf; + + /* Get tag and verify that it is ok. */ + whole_tag = *bp++; + tag_number = whole_tag & DER_TAGNUM_MASK; + + /* + * XXX This code does not (yet) handle the high-tag-number form! + */ + if (tag_number == DER_HIGH_TAG_NUMBER) { + PORT_SetError(SEC_ERROR_BAD_DER); + return SECFailure; + } + + if ((whole_tag & DER_CLASS_MASK) == DER_UNIVERSAL) { + /* Check that the universal tag number is one we implement. */ + switch (tag_number) { + case DER_BOOLEAN: + case DER_INTEGER: + case DER_BIT_STRING: + case DER_OCTET_STRING: + case DER_NULL: + case DER_OBJECT_ID: + case DER_SEQUENCE: + case DER_SET: + case DER_PRINTABLE_STRING: + case DER_T61_STRING: + case DER_IA5_STRING: + case DER_VISIBLE_STRING: + case DER_UTC_TIME: + case 0: /* end-of-contents tag */ + break; + default: + PORT_SetError(SEC_ERROR_BAD_DER); + return SECFailure; + } + } + + /* + * Get first byte of length code (might contain entire length, might not). + */ + contents_len = *bp++; + + /* + * If the high bit is set, then the length is in multibyte format, + * or the thing has an indefinite-length. + */ + if (contents_len & 0x80) { + int bytes_of_encoded_len; + + bytes_of_encoded_len = contents_len & 0x7f; + contents_len = 0; + + switch (bytes_of_encoded_len) { + case 4: + contents_len |= *bp++; + contents_len <<= 8; + /* fallthru */ + case 3: + contents_len |= *bp++; + contents_len <<= 8; + /* fallthru */ + case 2: + contents_len |= *bp++; + contents_len <<= 8; + /* fallthru */ + case 1: + contents_len |= *bp++; + break; + + case 0: + contents_len = der_indefinite_length (bp, end); + if (contents_len) + break; + /* fallthru */ + default: + PORT_SetError(SEC_ERROR_BAD_DER); + return SECFailure; + } + } + + if ((bp + contents_len) > end) { + /* Ran past end of buffer */ + PORT_SetError(SEC_ERROR_BAD_DER); + return SECFailure; + } + + *header_len_p = bp - buf; + *contents_len_p = contents_len; + + return SECSuccess; +} + +SECStatus +DER_Lengths(SECItem *item, int *header_len_p, PRUint32 *contents_len_p) +{ + return(der_capture(item->data, &item->data[item->len], header_len_p, + contents_len_p)); +} |