+/* Copyright (c) 1998,2011,2014 Apple Inc. All Rights Reserved.
+ *
+ * NOTICE: USE OF THE MATERIALS ACCOMPANYING THIS NOTICE IS SUBJECT
+ * TO THE TERMS OF THE SIGNED "FAST ELLIPTIC ENCRYPTION (FEE) REFERENCE
+ * SOURCE CODE EVALUATION AGREEMENT" BETWEEN APPLE, INC. AND THE
+ * ORIGINAL LICENSEE THAT OBTAINED THESE MATERIALS FROM APPLE,
+ * INC. ANY USE OF THESE MATERIALS NOT PERMITTED BY SUCH AGREEMENT WILL
+ * EXPOSE YOU TO LIABILITY.
+ ***************************************************************************
+ *
+ * enc64.c - encode/decode in 64-char IA5 format, per RFC 1421
+ *
+ * Revision History
+ * ----------------
+ * 11/27/98 dmitch
+ * Added ECDSA_VERIFY_ONLY dependencies.
+ * 10/06/98 ap
+ * Changed to compile with C++.
+ * 12 Dec 96 at NeXT
+ * Newlines optional in dec64() and isValidEnc64().
+ * 9 Oct 96 at NeXT
+ * Created.
+ */
+
+#include "enc64.h"
+#include "falloc.h"
+
+/*
+ * 11/27/98 dmitch: The ECDSA_VERIFY_ONLY symbol, when #defined, disables all
+ * of the code in this module except that which is necessary for ECDSA
+ * siggnature verification.
+ */
+
+#ifndef NULL
+#define NULL ((void *)0)
+#endif /* NULL */
+
+/*
+ * map a 6-bit binary value to a printable character.
+ */
+static const
+unsigned char bintoasc[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+/*
+ * Map an 7-bit printable character to its corresponding binary value.
+ * Any illegal characters return high bit set.
+ */
+static const
+unsigned char asctobin[] =
+{
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x3e, 0x80, 0x80, 0x80, 0x3f,
+ 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
+ 0x3c, 0x3d, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
+ 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+ 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
+ 0x17, 0x18, 0x19, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
+ 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
+ 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
+ 0x31, 0x32, 0x33, 0x80, 0x80, 0x80, 0x80, 0x80
+};
+
+/*
+ * map 6 bits to a printing char
+ */
+#define ENC(c) (bintoasc[((c) & 0x3f)])
+
+#define PAD '='
+//#define ENC_LINE_LEN 64
+
+#ifndef ECDSA_VERIFY_ONLY
+
+/*
+ * map one group of up to 3 bytes at inp to 4 bytes at outp.
+ * Count is number of valid bytes in *inp; if less than 3, the
+ * 1 or two extras must be zeros.
+ */
+static void encChunk(const unsigned char *inp,
+ unsigned char *outp,
+ int count)
+{
+ unsigned char c1, c2, c3, c4;
+
+ c1 = *inp >> 2;
+ c2 = ((inp[0] << 4) & 0x30) | ((inp[1] >> 4) & 0xf);
+ c3 = ((inp[1] << 2) & 0x3c) | ((inp[2] >> 6) & 0x3);
+ c4 = inp[2] & 0x3f;
+ *outp++ = ENC(c1);
+ *outp++ = ENC(c2);
+ if (count == 1) {
+ *outp++ = PAD;
+ *outp = PAD;
+ } else {
+ *outp++ = ENC(c3);
+ if (count == 2) {
+ *outp = PAD;
+ }
+ else {
+ *outp = ENC(c4);
+ }
+ }
+}
+
+/*
+ * Given input buffer inbuf, length inlen, encode to 64-char IA5 format.
+ * Result is fmalloc'd and returned; it is terminated by Microsoft-style
+ * newline and NULL. Its length (including the trailing newline and NULL)
+ * is returned in *outlen.
+ */
+
+unsigned char *enc64(const unsigned char *inbuf,
+ unsigned inlen,
+ unsigned *outlen) // RETURNED
+{
+ return enc64WithLines(inbuf, inlen, 0, outlen);
+}
+
+unsigned char *enc64WithLines(const unsigned char *inbuf,
+ unsigned inlen,
+ unsigned linelen,
+ unsigned *outlen)
+{
+ unsigned outTextLen;
+ unsigned len; // to malloc, liberal
+ unsigned olen = 0; // actual output size
+ unsigned char *outbuf;
+ unsigned char endbuf[3];
+ unsigned i;
+ unsigned char *outp;
+ unsigned numLines;
+ unsigned thisLine;
+
+ outTextLen = ((inlen + 2) / 3) * 4;
+ if(linelen) {
+ /*
+ * linelen must be 0 mod 4 for this to work; round up...
+ */
+ if((linelen & 0x03) != 0) {
+ linelen = (linelen + 3) & 0xfffffffc;
+ }
+ numLines = (outTextLen + linelen - 1)/ linelen;
+ }
+ else {
+ numLines = 1;
+ }
+
+ /*
+ * Total output size = encoded text size plus one newline per
+ * line of output, plus trailing NULL. For Microsoft compatibility,
+ * we always generate newlines as \r\n; when decoding, we tolerate
+ * \r\n or \n.
+ */
+ len = outTextLen + (2 * numLines) + 1;
+ outbuf = (unsigned char*) fmalloc(len);
+ outp = outbuf;
+ thisLine = 0;
+
+ while(inlen) {
+ if(inlen < 3) {
+ for(i=0; i<3; i++) {
+ if(i < inlen) {
+ endbuf[i] = inbuf[i];
+ }
+ else {
+ endbuf[i] = 0;
+ }
+ }
+ encChunk(endbuf, outp, inlen);
+ inlen = 0;
+ }
+ else {
+ encChunk(inbuf, outp, 3);
+ inlen -= 3;
+ inbuf += 3;
+ }
+ outp += 4;
+ thisLine += 4;
+ olen += 4;
+ if((linelen != 0) && (thisLine >= linelen) && inlen) {
+ /*
+ * last trailing newline added below
+ * Note we don't split 4-byte output chunks over newlines
+ */
+ *outp++ = '\r';
+ *outp++ = '\n';
+ olen += 2;
+ thisLine = 0;
+ }
+ }
+ *outp++ = '\r';
+ *outp++ = '\n';
+ *outp = '\0';
+ olen += 3;
+ *outlen = olen;
+ return outbuf;
+}
+
+#endif /* ECDSA_VERIFY_ONLY */
+
+static inline int isWhite(unsigned char c)
+{
+ switch(c) {
+ case '\n':
+
+ case '\r':
+
+ case ' ':
+
+ case '\t':
+
+ case '\0':
+ return 1;
+
+ default:
+
+ return 0;
+
+ }
+}
+
+/*
+ * Strip off all whitespace from a (supposedly) enc64-format string.
+ * Returns a malloc'd string.
+ */
+static unsigned char *stringCleanse(const unsigned char *inbuf,
+ unsigned inlen,
+ unsigned *outlen)
+{
+ unsigned char *news; // cleansed inbuf
+ unsigned newsDex; // index into news
+ unsigned i;
+
+ news = (unsigned char*) fmalloc(inlen);
+ newsDex = 0;
+ for(i=0; i<inlen; i++) {
+ if(!isWhite(inbuf[i])) {
+ news[newsDex++] = inbuf[i];
+ }
+ }
+ *outlen = newsDex;
+ return news;
+}
+
+/*
+ * Given input buffer inbuf, length inlen, decode from 64-char IA5 format to
+ * binary. Result is fmalloced and returned; its length is returned in *outlen.
+ * NULL return indicates corrupted input.
+ *
+ * All whitespace in input is ignored.
+ */
+unsigned char *dec64(const unsigned char *inbuf,
+ unsigned inlen,
+ unsigned *outlen)
+{
+ unsigned char *outbuf;
+ unsigned char *outp; // malloc'd outbuf size
+ unsigned obuflen;
+ const unsigned char *bp;
+ unsigned olen = 0; // actual output size
+ unsigned char c1, c2, c3, c4;
+ unsigned char j;
+ unsigned thisOlen;
+ unsigned char *news; // cleansed inbuf
+ unsigned newsLen;
+
+ /*
+ * Strip out all whitespace; remainder must be multiple of four
+ * characters
+ */
+ news = stringCleanse(inbuf, inlen, &newsLen);
+ if((newsLen & 0x03) != 0) {
+ ffree(news);
+ return (unsigned char*) NULL;
+ }
+ inlen = newsLen;
+ bp = news;
+
+ obuflen = (inlen / 4) * 3;
+ outbuf = (unsigned char*) fmalloc(obuflen);
+ outp = outbuf;
+
+ while (inlen) {
+ /*
+ * Note inlen is always a multiple of four here
+ */
+ if (*bp & 0x80 || (c1 = asctobin[*bp]) & 0x80) {
+ goto errorOut;
+ }
+ inlen--;
+ bp++;
+ if (*bp & 0x80 || (c2 = asctobin[*bp]) & 0x80){
+ goto errorOut;
+ }
+ inlen--;
+ bp++;
+ if (*bp == PAD) {
+ /*
+ * two input bytes, one output byte
+ */
+ c3 = c4 = 0;
+ thisOlen = 1;
+ if (c2 & 0xf) {
+ goto errorOut;
+ }
+ bp++;
+ inlen--;
+ if (*bp == PAD) {
+ bp++;
+ inlen--;
+ if(inlen > 0) {
+ goto errorOut;
+ }
+ }
+ else {
+ goto errorOut;
+ }
+ } else if (*bp & 0x80 || (c3 = asctobin[*bp]) & 0x80) {
+ goto errorOut;
+ } else {
+ bp++;
+ inlen--;
+ if (*bp == PAD) {
+ /*
+ * Three input bytes, two output
+ */
+ c4 = 0;
+ thisOlen = 2;
+ if (c3 & 3) {
+ goto errorOut;
+ }
+ } else if (*bp & 0x80 || (c4 = asctobin[*bp]) & 0x80) {
+ goto errorOut;
+ } else {
+ /*
+ * Normal non-pad case
+ */
+ thisOlen = 3;
+ }
+ bp++;
+ inlen--;
+ }
+ j = (c1 << 2) | (c2 >> 4);
+ *outp++ = j;
+ if(thisOlen > 1) {
+ j = (c2 << 4) | (c3 >> 2);
+ *outp++ = j;
+ if(thisOlen == 3) {
+ j = (c3 << 6) | c4;
+ *outp++ = j;
+ }
+ }
+ olen += thisOlen;
+ }
+ ffree(news);
+ *outlen = olen;
+ return outbuf; /* normal return */
+
+errorOut:
+ ffree(news);
+ ffree(outbuf);
+ return (unsigned char*) NULL;
+}
+
+/*
+ * Determine if specified input data is valid enc64 format. Returns 1
+ * if valid, 0 if not.
+ * This doesn't do a full enc64 parse job; it scans for legal characters
+ * and proper sync when a possible pad is found.
+ */
+int isValidEnc64(const unsigned char *inbuf,
+ unsigned inlen)
+{
+ int padChars = 0; // running count of PAD chars
+ int validEncChars = 0;
+ unsigned char c;
+
+ /*
+ * -- scan inbuf
+ * -- skip whitespace
+ * -- count valid chars
+ * -- ensure not more than 2 PAD chars, only at end
+ * -- ensure valid chars mod 4 == 0
+ */
+
+ while(inlen) {
+ c = *inbuf++;
+ inlen--;
+ if(isWhite(c)) {
+ continue;
+ }
+ if(c == PAD) {
+ if(++padChars > 2) {
+ return 0; // max of 2 PAD chars at end
+ }
+ }
+ else if(padChars > 0) {
+ return 0; // no normal chars after seeing PAD
+ }
+ else if((c & 0x80) || ((asctobin[c]) & 0x80)) {
+ return 0; // invalid encoded char
+ }
+ validEncChars++;
+ }
+ if((validEncChars & 0x03) != 0) {
+ return 0;
+ }
+ else {
+ return 1;
+ }
+}
projects / apple / security.git / blobdiff