]> git.saurik.com Git - apple/security.git/blobdiff - Security/libsecurity_apple_x509_tp/lib/cuEnc64.c
Security-57031.1.35.tar.gz
[apple/security.git] / Security / libsecurity_apple_x509_tp / lib / cuEnc64.c
diff --git a/Security/libsecurity_apple_x509_tp/lib/cuEnc64.c b/Security/libsecurity_apple_x509_tp/lib/cuEnc64.c
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+/*
+ * Copyright (c) 1998-2003,2010-2012 Apple Inc. All Rights Reserved.
+ * 
+ * The contents of this file constitute Original Code as defined in and are
+ * subject to the Apple Public Source License Version 1.2 (the 'License').
+ * You may not use this file except in compliance with the License. Please 
+ * obtain a copy of the License at http://www.apple.com/publicsource and 
+ * read it before using this file.
+ * 
+ * This Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
+ * Please see the License for the specific language governing rights and 
+ * limitations under the License.
+ *
+ * cuEnc64.c - encode/decode in 64-char IA5 format, per RFC 1421
+ */
+
+#include "cuEnc64.h"
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
+
+#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            '='
+
+/*
+ * 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 *cuEnc64(const unsigned char *inbuf,
+       unsigned inlen,
+       unsigned *outlen)               // RETURNED
+{
+       return cuEnc64WithLines(inbuf, inlen, 0, outlen);
+}
+
+unsigned char *cuEnc64WithLines(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. We always generate newlines 
+        * as \n; when decoding, we tolerate \r\n (Microsoft) or \n.
+        */
+       len = outTextLen + (2 * numLines) + 1;
+       outbuf = (unsigned char*)malloc(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++ = '\n';
+                       olen++;
+                       thisLine = 0;
+           }
+       }
+       *outp++ = '\n';
+       *outp = '\0';
+       olen += 2;
+       *outlen = olen;
+       return outbuf;
+}
+
+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*)malloc(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 malloced and returned; its length is returned in *outlen.
+ * NULL return indicates corrupted input.
+ *
+ * All whitespace in input is ignored.
+ */
+unsigned char *cuDec64(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) {
+           free(news);
+           return (unsigned char*) NULL;
+       }
+       inlen = newsLen;
+       bp = news;
+
+       obuflen = (inlen / 4) * 3;
+       outbuf = (unsigned char*)malloc(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;
+       }
+       free(news);
+       *outlen = olen;
+       return outbuf;                  /* normal return */
+
+errorOut:
+       free(news);
+       free(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 cuIsValidEnc64(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;
+       }
+}
+
+/* 
+ * Text parsing routines. 
+ *
+ * Search incoming text for specified string. Does not assume inText is
+ * NULL terminated. Returns pointer to start of found string in inText.
+ */
+static const char *findStr(
+       const char *inText,
+       unsigned inTextLen,
+       const char *str)                                // NULL terminated - search for this
+{
+       /* probably not the hottest string search algorithm... */
+       const char *cp;
+       size_t srchStrLen = strlen(str);
+       char c = str[0];
+       
+       /* last char * we can search in inText for start of str */
+       const char *endCp = inText + inTextLen - srchStrLen;
+       
+       for(cp=inText; cp<=endCp; cp++) {
+               if(*cp == c) {
+                       if(!memcmp(cp, str, srchStrLen)) {
+                               return cp;
+                       }
+               }
+       }
+       return NULL;
+}
+
+/*
+ * Obtain one line from current text. Returns a mallocd, NULL-terminated string
+ * which caller must free(). Also returns the number of chars consumed including
+ * the returned chars PLUS EOL terminators (\n and/or \r).
+ *
+ * ALWAYS returns a mallocd string if there is ANY data remaining per the 
+ * incoming inTextLen. Returns NULL if inTextLen is zero.
+ */
+static const char *getLine(
+       const char *inText,
+       unsigned inTextLen,                     // RETURNED
+       unsigned *consumed)                     // RETURNED
+       
+{
+       *consumed = 0;
+       const char *cp = inText;
+       const char *newline = NULL;             // if we found a newline, this points to the first one
+       
+       while(inTextLen) {
+               char c = *cp;
+               if((c == '\r') || (c == '\n')) {
+                       if(newline == NULL) {
+                               /* first newline */
+                               newline = cp;
+                       }
+               }
+               else if(newline != NULL) {
+                       /* non newline after newline, done */
+                       break;
+               }
+               (*consumed)++;
+               inTextLen--;
+               cp++;
+       }
+       ptrdiff_t linelen;
+       if(newline) {
+               linelen = newline - inText;
+       }
+       else {
+               linelen = *consumed;
+       }
+       char *rtn = (char *)malloc(linelen + 1);
+       memmove(rtn, inText, linelen);
+       rtn[linelen] = 0;
+       return rtn;
+}
+
+#define UNSUPPORTED_FORMAT_ERR -25256
+
+/*
+ * Given input buffer containing a PEM-encoded certificate, convert to DER
+ * and return in outbuf. Result is malloced and must be freed by caller;
+ * its length is returned in *outlen. Returns 0 on success.
+ */
+int cuConvertPem(
+       const unsigned char *inbuf,
+       unsigned inlen,
+       unsigned char **outbuf, // RETURNED (caller must free)
+       unsigned *outlen)                       // RETURNED
+{
+       unsigned lenToGo =  (inlen) ? inlen : 0;
+       const char       *currCp = (inbuf) ? (const char *)inbuf : NULL;
+       const char *currLine = NULL;            // mallocd by getLine()
+       unsigned consumed;
+       int ortn = 0;
+       const char *start64;
+       unsigned base64Len;     
+       const char *end64;
+       unsigned char *decData;
+       unsigned decDataLen;
+       
+       /* search to START line, parse it to get type/format/alg */
+       const char *startLine = findStr(currCp, lenToGo, "-----BEGIN");
+       if(startLine != NULL) {
+               /* possibly skip over leading garbage */
+               consumed = (unsigned)(startLine - currCp);
+               lenToGo -= consumed;
+               currCp = startLine;
+               
+               /* get C string of START line */
+               currLine = getLine(startLine, lenToGo, &consumed);
+               if(currLine == NULL) {
+                       /* somehow got here with no data */
+                       // assert(lenToGo == 0);
+                       ortn = UNSUPPORTED_FORMAT_ERR;
+                       goto errOut;
+               }
+               // assert(consumed <= lenToGo);
+               currCp  += consumed;
+               lenToGo -= consumed;
+               
+               free((void *)currLine);
+       }
+
+       /* Skip empty lines.     */
+       for( ; ; ) {
+               currLine = getLine(currCp, lenToGo, &consumed);
+               if(currLine == NULL) {
+                       /* out of data */
+                       ortn = UNSUPPORTED_FORMAT_ERR;
+                       goto errOut;
+               }
+               int skipThis = 0;
+               size_t lineLen = strlen(currLine);
+               if(lineLen == 0) {
+                       /* empty line */
+                       skipThis = 1;
+               }
+               free((void *)currLine);
+
+               if(!skipThis) {
+                       /* looks like good stuff; process */
+                       break;
+               }
+               /* skip this line */
+               // assert(consumed <= lenToGo);
+               currCp  += consumed;
+               lenToGo -= consumed;
+       }
+       if(lenToGo == 0) {
+               /* no valid base64 data */
+               ortn = UNSUPPORTED_FORMAT_ERR;
+               goto errOut;
+       }
+
+       /* 
+        * currCP points to start of base64 data - mark it and search for end line.
+        * We skip everything after the end line.
+        */
+       start64 = currCp;
+       base64Len = lenToGo;                    // if no END
+       end64 = findStr(currCp, lenToGo, "-----END");
+       if(end64 != NULL) {
+               if(end64 == start64) {
+                       /* Empty, nothing between START and END */
+                       ortn = UNSUPPORTED_FORMAT_ERR;
+                       goto errOut;
+               }
+               base64Len = (unsigned)(end64 - start64);
+       }
+       /* else no END, no reason to complain about that as long as base64 decode works OK */
+       
+       /* Base 64 decode */
+       decData = cuDec64((const unsigned char *)start64, base64Len, &decDataLen);
+       if(decData == NULL) {
+               /* bad base64 data */
+               ortn = UNSUPPORTED_FORMAT_ERR;
+               goto errOut;
+       }
+       
+       if(outlen) {
+               *outlen = decDataLen;
+       }
+       if(outbuf) {
+               *outbuf = decData;
+       }
+       else {
+               free((void *)decData);
+       }
+       
+errOut:
+       return ortn;
+}