1/*++ 2/* NAME 3/* hex_quote 3 4/* SUMMARY 5/* quote/unquote text, HTTP style. 6/* SYNOPSIS 7/* #include <hex_quote.h> 8/* 9/* VSTRING *hex_quote(hex, raw) 10/* VSTRING *hex; 11/* const char *raw; 12/* 13/* VSTRING *hex_unquote(raw, hex) 14/* VSTRING *raw; 15/* const char *hex; 16/* DESCRIPTION 17/* hex_quote() takes a null-terminated string and replaces non-printable 18/* and whitespace characters and the % by %XX, XX being the two-digit 19/* hexadecimal equivalent. 20/* The hexadecimal codes are produced as upper-case characters. The result 21/* value is the hex argument. 22/* 23/* hex_unquote() performs the opposite transformation. This function 24/* understands lowercase, uppercase, and mixed case %XX sequences. The 25/* result value is the raw argument in case of success, a null pointer 26/* otherwise. 27/* BUGS 28/* hex_quote() cannot process null characters in data. 29/* LICENSE 30/* .ad 31/* .fi 32/* The Secure Mailer license must be distributed with this software. 33/* AUTHOR(S) 34/* Wietse Venema 35/* IBM T.J. Watson Research 36/* P.O. Box 704 37/* Yorktown Heights, NY 10598, USA 38/*--*/ 39 40/* System library. */ 41 42#include "sys_defs.h" 43#include <ctype.h> 44 45/* Utility library. */ 46 47#include "msg.h" 48#include "vstring.h" 49#include "hex_quote.h" 50 51/* Application-specific. */ 52 53#define STR(x) vstring_str(x) 54#define LEN(x) VSTRING_LEN(x) 55 56/* hex_quote - raw data to quoted */ 57 58VSTRING *hex_quote(VSTRING *hex, const char *raw) 59{ 60 const char *cp; 61 int ch; 62 63 VSTRING_RESET(hex); 64 for (cp = raw; (ch = *(unsigned const char *) cp) != 0; cp++) { 65 if (ch != '%' && !ISSPACE(ch) && ISPRINT(ch)) { 66 VSTRING_ADDCH(hex, ch); 67 } else { 68 vstring_sprintf_append(hex, "%%%02X", ch); 69 } 70 } 71 VSTRING_TERMINATE(hex); 72 return (hex); 73} 74 75/* hex_unquote - quoted data to raw */ 76 77VSTRING *hex_unquote(VSTRING *raw, const char *hex) 78{ 79 const char *cp; 80 int ch; 81 82 VSTRING_RESET(raw); 83 for (cp = hex; (ch = *cp) != 0; cp++) { 84 if (ch == '%') { 85 if (ISDIGIT(cp[1])) 86 ch = (cp[1] - '0') << 4; 87 else if (cp[1] >= 'a' && cp[1] <= 'f') 88 ch = (cp[1] - 'a' + 10) << 4; 89 else if (cp[1] >= 'A' && cp[1] <= 'F') 90 ch = (cp[1] - 'A' + 10) << 4; 91 else 92 return (0); 93 if (ISDIGIT(cp[2])) 94 ch |= (cp[2] - '0'); 95 else if (cp[2] >= 'a' && cp[2] <= 'f') 96 ch |= (cp[2] - 'a' + 10); 97 else if (cp[2] >= 'A' && cp[2] <= 'F') 98 ch |= (cp[2] - 'A' + 10); 99 else 100 return (0); 101 cp += 2; 102 } 103 VSTRING_ADDCH(raw, ch); 104 } 105 VSTRING_TERMINATE(raw); 106 return (raw); 107} 108 109#ifdef TEST 110 111 /* 112 * Proof-of-concept test program: convert to hex and back. 113 */ 114#include <vstream.h> 115 116#define BUFLEN 1024 117 118static ssize_t read_buf(VSTREAM *fp, VSTRING *buf) 119{ 120 ssize_t len; 121 122 VSTRING_RESET(buf); 123 len = vstream_fread(fp, STR(buf), vstring_avail(buf)); 124 VSTRING_AT_OFFSET(buf, len); /* XXX */ 125 VSTRING_TERMINATE(buf); 126 return (len); 127} 128 129int main(int unused_argc, char **unused_argv) 130{ 131 VSTRING *raw = vstring_alloc(BUFLEN); 132 VSTRING *hex = vstring_alloc(100); 133 ssize_t len; 134 135 while ((len = read_buf(VSTREAM_IN, raw)) > 0) { 136 hex_quote(hex, STR(raw)); 137 if (hex_unquote(raw, STR(hex)) == 0) 138 msg_fatal("bad input: %.100s", STR(hex)); 139 if (LEN(raw) != len) 140 msg_fatal("len %ld != raw len %ld", (long) len, (long) LEN(raw)); 141 if (vstream_fwrite(VSTREAM_OUT, STR(raw), LEN(raw)) != LEN(raw)) 142 msg_fatal("write error: %m"); 143 } 144 vstream_fflush(VSTREAM_OUT); 145 vstring_free(raw); 146 vstring_free(hex); 147 return (0); 148} 149 150#endif 151