1 /* $NetBSD: hex_quote.c,v 1.1.1.1 2009/06/23 10:09:00 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* hex_quote 3 6 /* SUMMARY 7 /* quote/unquote text, HTTP style. 8 /* SYNOPSIS 9 /* #include <hex_quote.h> 10 /* 11 /* VSTRING *hex_quote(hex, raw) 12 /* VSTRING *hex; 13 /* const char *raw; 14 /* 15 /* VSTRING *hex_unquote(raw, hex) 16 /* VSTRING *raw; 17 /* const char *hex; 18 /* DESCRIPTION 19 /* hex_quote() takes a null-terminated string and replaces non-printable 20 /* and whitespace characters and the % by %XX, XX being the two-digit 21 /* hexadecimal equivalent. 22 /* The hexadecimal codes are produced as upper-case characters. The result 23 /* value is the hex argument. 24 /* 25 /* hex_unquote() performs the opposite transformation. This function 26 /* understands lowercase, uppercase, and mixed case %XX sequences. The 27 /* result value is the raw argument in case of success, a null pointer 28 /* otherwise. 29 /* BUGS 30 /* hex_quote() cannot process null characters in data. 31 /* LICENSE 32 /* .ad 33 /* .fi 34 /* The Secure Mailer license must be distributed with this software. 35 /* AUTHOR(S) 36 /* Wietse Venema 37 /* IBM T.J. Watson Research 38 /* P.O. Box 704 39 /* Yorktown Heights, NY 10598, USA 40 /*--*/ 41 42 /* System library. */ 43 44 #include "sys_defs.h" 45 #include <ctype.h> 46 47 /* Utility library. */ 48 49 #include "msg.h" 50 #include "vstring.h" 51 #include "hex_quote.h" 52 53 /* Application-specific. */ 54 55 #define STR(x) vstring_str(x) 56 #define LEN(x) VSTRING_LEN(x) 57 58 /* hex_quote - raw data to quoted */ 59 60 VSTRING *hex_quote(VSTRING *hex, const char *raw) 61 { 62 const char *cp; 63 int ch; 64 65 VSTRING_RESET(hex); 66 for (cp = raw; (ch = *(unsigned const char *) cp) != 0; cp++) { 67 if (ch != '%' && !ISSPACE(ch) && ISPRINT(ch)) { 68 VSTRING_ADDCH(hex, ch); 69 } else { 70 vstring_sprintf_append(hex, "%%%02X", ch); 71 } 72 } 73 VSTRING_TERMINATE(hex); 74 return (hex); 75 } 76 77 /* hex_unquote - quoted data to raw */ 78 79 VSTRING *hex_unquote(VSTRING *raw, const char *hex) 80 { 81 const char *cp; 82 int ch; 83 84 VSTRING_RESET(raw); 85 for (cp = hex; (ch = *cp) != 0; cp++) { 86 if (ch == '%') { 87 if (ISDIGIT(cp[1])) 88 ch = (cp[1] - '0') << 4; 89 else if (cp[1] >= 'a' && cp[1] <= 'f') 90 ch = (cp[1] - 'a' + 10) << 4; 91 else if (cp[1] >= 'A' && cp[1] <= 'F') 92 ch = (cp[1] - 'A' + 10) << 4; 93 else 94 return (0); 95 if (ISDIGIT(cp[2])) 96 ch |= (cp[2] - '0'); 97 else if (cp[2] >= 'a' && cp[2] <= 'f') 98 ch |= (cp[2] - 'a' + 10); 99 else if (cp[2] >= 'A' && cp[2] <= 'F') 100 ch |= (cp[2] - 'A' + 10); 101 else 102 return (0); 103 cp += 2; 104 } 105 VSTRING_ADDCH(raw, ch); 106 } 107 VSTRING_TERMINATE(raw); 108 return (raw); 109 } 110 111 #ifdef TEST 112 113 /* 114 * Proof-of-concept test program: convert to hex and back. 115 */ 116 #include <vstream.h> 117 118 #define BUFLEN 1024 119 120 static ssize_t read_buf(VSTREAM *fp, VSTRING *buf) 121 { 122 ssize_t len; 123 124 VSTRING_RESET(buf); 125 len = vstream_fread(fp, STR(buf), vstring_avail(buf)); 126 VSTRING_AT_OFFSET(buf, len); /* XXX */ 127 VSTRING_TERMINATE(buf); 128 return (len); 129 } 130 131 int main(int unused_argc, char **unused_argv) 132 { 133 VSTRING *raw = vstring_alloc(BUFLEN); 134 VSTRING *hex = vstring_alloc(100); 135 ssize_t len; 136 137 while ((len = read_buf(VSTREAM_IN, raw)) > 0) { 138 hex_quote(hex, STR(raw)); 139 if (hex_unquote(raw, STR(hex)) == 0) 140 msg_fatal("bad input: %.100s", STR(hex)); 141 if (LEN(raw) != len) 142 msg_fatal("len %ld != raw len %ld", (long) len, (long) LEN(raw)); 143 if (vstream_fwrite(VSTREAM_OUT, STR(raw), LEN(raw)) != LEN(raw)) 144 msg_fatal("write error: %m"); 145 } 146 vstream_fflush(VSTREAM_OUT); 147 vstring_free(raw); 148 vstring_free(hex); 149 return (0); 150 } 151 152 #endif 153