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Diffstat (limited to 'common/base64.c')
| -rw-r--r-- | common/base64.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/common/base64.c b/common/base64.c new file mode 100644 index 0000000..7e66933 --- /dev/null +++ b/common/base64.c @@ -0,0 +1,192 @@ +/* + * Copyright (c) 1996, 1998 by Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS + * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE + * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR + * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS + * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS + * SOFTWARE. + */ + +/* + * Portions Copyright (c) 1995 by International Business Machines, Inc. + * + * International Business Machines, Inc. (hereinafter called IBM) grants + * permission under its copyrights to use, copy, modify, and distribute this + * Software with or without fee, provided that the above copyright notice and + * all paragraphs of this notice appear in all copies, and that the name of IBM + * not be used in connection with the marketing of any product incorporating + * the Software or modifications thereof, without specific, written prior + * permission. + * + * To the extent it has a right to do so, IBM grants an immunity from suit + * under its patents, if any, for the use, sale or manufacture of products to + * the extent that such products are used for performing Domain Name System + * dynamic updates in TCP/IP networks by means of the Software. No immunity is + * granted for any product per se or for any other function of any product. + * + * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, + * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING + * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN + * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. + */ + +#include "config.h" + +#include "base64.h" + +#include <assert.h> +#include <ctype.h> +#include <stdlib.h> +#include <string.h> + +static const char Base64[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +static const char Pad64 = '='; + +/* skips all whitespace anywhere. + converts characters, four at a time, starting at (or after) + src from base - 64 numbers into three 8 bit bytes in the target area. + it returns the number of data bytes stored at the target, or -1 on error. + */ + +int +p11_b64_pton (const char *src, + size_t length, + unsigned char *target, + size_t targsize) +{ + int tarindex, state, ch; + char *pos; + const char *end; + + state = 0; + tarindex = 0; + end = src + length; + + for (;;) { + src++; + if (src == end) { + ch = 0; + break; + } + + ch = *src; + if (isspace ((unsigned char) ch)) /* Skip whitespace anywhere. */ + continue; + + if (ch == Pad64) + break; + + pos = strchr (Base64, ch); + if (pos == 0) /* A non-base64 character. */ + return (-1); + + switch (state) { + case 0: + if (target) { + if ((size_t)tarindex >= targsize) + return (-1); + target[tarindex] = (pos - Base64) << 2; + } + state = 1; + break; + case 1: + if (target) { + if ((size_t) tarindex + 1 >= targsize) + return (-1); + target[tarindex] |= (pos - Base64) >> 4; + target[tarindex + 1] = ((pos - Base64) & 0x0f) + << 4; + } + tarindex++; + state = 2; + break; + case 2: + if (target) { + if ((size_t) tarindex + 1 >= targsize) + return (-1); + target[tarindex] |= (pos - Base64) >> 2; + target[tarindex + 1] = ((pos - Base64) & 0x03) + << 6; + } + tarindex++; + state = 3; + break; + case 3: + if (target) { + if ((size_t) tarindex >= targsize) + return (-1); + target[tarindex] |= (pos - Base64); + } + tarindex++; + state = 0; + break; + default: + abort(); + } + } + + /* + * We are done decoding Base-64 chars. Let's see if we ended + * on a byte boundary, and/or with erroneous trailing characters. + */ + + if (ch == Pad64) { /* We got a pad char. */ + ch = *src++; /* Skip it, get next. */ + switch (state) { + case 0: /* Invalid = in first position */ + case 1: /* Invalid = in second position */ + return (-1); + + case 2: /* Valid, means one byte of info */ + /* Skip any number of spaces. */ + for ((void) NULL; src != end; ch = *src++) + if (!isspace((unsigned char) ch)) + break; + /* Make sure there is another trailing = sign. */ + if (ch != Pad64) + return (-1); + ch = *src++; /* Skip the = */ + /* Fall through to "single trailing =" case. */ + /* FALLTHROUGH */ + + case 3: /* Valid, means two bytes of info */ + /* + * We know this char is an =. Is there anything but + * whitespace after it? + */ + for (src++; src != end; ch = *src++) + if (!isspace((unsigned char) ch)) + return (-1); + + /* + * Now make sure for cases 2 and 3 that the "extra" + * bits that slopped past the last full byte were + * zeros. If we don't check them, they become a + * subliminal channel. + */ + if (target && target[tarindex] != 0) + return (-1); + } + } else { + /* + * We ended by seeing the end of the string. Make sure we + * have no partial bytes lying around. + */ + if (state != 0) + return (-1); + } + + return (tarindex); +} |