Collection of Internet/Collection of Internet.iso/msdos/lynx/source/www/library/implemen/htaautil.c

C/C++ Source or Header | 1994-10-25 | 15.6 KB | 573 lines

/* MODULE                            HTAAUtil.c
**        COMMON PARTS OF ACCESS AUTHORIZATION MODULE
**            FOR BOTH SERVER AND BROWSER
**
** IMPORTANT:
**    Routines in this module use dynamic allocation, but free
**    automatically all the memory reserved by them.
**
**    Therefore the caller never has to (and never should)
**    free() any object returned by these functions.
**
**    Therefore also all the strings returned by this package
**    are only valid until the next call to the same function
**    is made. This approach is selected, because of the nature
**    of access authorization: no string returned by the package
**    needs to be valid longer than until the next call.
**
**    This also makes it easy to plug the AA package in:
**    you don't have to ponder whether to free() something
**    here or is it done somewhere else (because it is always
**    done somewhere else).
**
**    The strings that the package needs to store are copied
**    so the original strings given as parameters to AA
**    functions may be freed or modified with no side effects.
**
**    The AA package does not free() anything else than what
**    it has itself allocated.
**
**    AA (Access Authorization) package means modules which
**    names start with HTAA.
**
** AUTHORS:
**    AL    Ari Luotonen    [e-mail]
**    MD     Mark Donszelmann    [e-mail]
**
** HISTORY:
**     8 Nov 93  MD    (VMS only) Added case insensitive comparison in HTAA_templateCaseMatch
**
**
** BUGS:
**
**
*/
#include"capalloc.h"
#include"capstdio.h"
#include <string.h>
#include "HTUtils.h"
#include "tcp.h"    /* NETREAD() etc.    */
#include "HTAAUtil.h"    /* Implemented here    */
#include "HTAssoc.h"    /* Assoc list        */


/* PUBLIC                        HTAAScheme_enum()
**        TRANSLATE SCHEME NAME INTO
**        A SCHEME ENUMERATION
**
** ON ENTRY:
**    name        is a string representing the scheme name.
**
** ON EXIT:
**    returns        the enumerated constant for that scheme.
*/
PUBLIC HTAAScheme HTAAScheme_enum ARGS1(CONST char*, name)
{
    static char *upcased = NULL;
    char *cur;

    if (!name) return HTAA_UNKNOWN;

    StrAllocCopy(upcased, name);
    cur = upcased;
    while (*cur) {
    *cur = TOUPPER(*cur);
    cur++;
    }

    if (!strncmp(upcased, "NONE", 4))
    return HTAA_NONE;
    else if (!strncmp(upcased, "BASIC", 5))
    return HTAA_BASIC;
    else if (!strncmp(upcased, "PUBKEY", 6))
    return HTAA_PUBKEY;
    else if (!strncmp(upcased, "KERBEROSV4", 10))
    return HTAA_KERBEROS_V4;
    else if (!strncmp(upcased, "KERBEROSV5", 10))
    return HTAA_KERBEROS_V5;
    else
    return HTAA_UNKNOWN;
}


/* PUBLIC                        HTAAScheme_name()
**            GET THE NAME OF A GIVEN SCHEME
** ON ENTRY:
**    scheme        is one of the scheme enum values:
**            HTAA_NONE, HTAA_BASIC, HTAA_PUBKEY, ...
**
** ON EXIT:
**    returns        the name of the scheme, i.e.
**            "None", "Basic", "Pubkey", ...
*/
PUBLIC char *HTAAScheme_name ARGS1(HTAAScheme, scheme)
{
    switch (scheme) {
      case HTAA_NONE:        return "None";          break;
      case HTAA_BASIC:        return "Basic";         break;
      case HTAA_PUBKEY:        return "Pubkey";        break;
      case HTAA_KERBEROS_V4:    return "KerberosV4";    break;
      case HTAA_KERBEROS_V5:    return "KerberosV5";    break;
      case HTAA_UNKNOWN:    return "UNKNOWN";       break;
      default:            return "THIS-IS-A-BUG";
    }
}


/* PUBLIC                            HTAAMethod_enum()
**        TRANSLATE METHOD NAME INTO AN ENUMERATED VALUE
** ON ENTRY:
**    name        is the method name to translate.
**
** ON EXIT:
**    returns        HTAAMethod enumerated value corresponding
**            to the given name.
*/
PUBLIC HTAAMethod HTAAMethod_enum ARGS1(CONST char *, name)
{
    char tmp[MAX_METHODNAME_LEN+1];
    CONST char *src = name;
    char *dest = tmp;

    if (!name) return METHOD_UNKNOWN;

    while (*src) {
    *dest = TOUPPER(*src);
    dest++;
    src++;
    }
    *dest = 0;

    if (0==strcmp(tmp, "GET"))
    return METHOD_GET;
    else if (0==strcmp(tmp, "PUT"))
    return METHOD_PUT;
    else
    return METHOD_UNKNOWN;
}


/* PUBLIC                        HTAAMethod_name()
**            GET THE NAME OF A GIVEN METHOD
** ON ENTRY:
**    method        is one of the method enum values:
**            METHOD_GET, METHOD_PUT, ...
**
** ON EXIT:
**    returns        the name of the scheme, i.e.
**            "GET", "PUT", ...
*/
PUBLIC char *HTAAMethod_name ARGS1(HTAAMethod, method)
{
    switch (method) {
      case METHOD_GET:        return "GET";           break;
      case METHOD_PUT:        return "PUT";           break;
      case METHOD_UNKNOWN:    return "UNKNOWN";       break;
      default:            return "THIS-IS-A-BUG";
    }
}


/* PUBLIC                        HTAAMethod_inList()
**        IS A METHOD IN A LIST OF METHOD NAMES
** ON ENTRY:
**    method        is the method to look for.
**    list        is a list of method names.
**
** ON EXIT:
**    returns        YES, if method was found.
**            NO, if not found.
*/
PUBLIC BOOL HTAAMethod_inList ARGS2(HTAAMethod,    method,
                    HTList *,    list)
{
    HTList *cur = list;
    char *item;

    while (NULL != (item = (char*)HTList_nextObject(cur))) {
#ifndef RELEASE
    if (TRACE) fprintf(stderr, " %s", item);
#endif /* RELEASE */
    if (method == HTAAMethod_enum(item))
        return YES;
    }

    return NO;    /* Not found */
}



/* PUBLIC                        HTAA_templateMatch()
**        STRING COMPARISON FUNCTION FOR FILE NAMES
**           WITH ONE WILDCARD * IN THE TEMPLATE
** NOTE:
**    This is essentially the same code as in HTRules.c, but it
**    cannot be used because it is embedded in between other code.
**    (In fact, HTRules.c should use this routine, but then this
**     routine would have to be more sophisticated... why is life
**     sometimes so hard...)
**
** ON ENTRY:
**    template    is a template string to match the file name
**            agaist, may contain a single wildcard
**            character * which matches zero or more
**            arbitrary characters.
**    filename    is the filename (or pathname) to be matched
**            agaist the template.
**
** ON EXIT:
**    returns        YES, if filename matches the template.
**            NO, otherwise.
*/
PUBLIC BOOL HTAA_templateMatch ARGS2(CONST char *, template,
                     CONST char *, filename)
{
    CONST char *p = template;
    CONST char *q = filename;
    int m;

    for( ; *p  &&  *q  &&  *p == *q; p++, q++)    /* Find first mismatch */
    ; /* do nothing else */

    if (!*p && !*q)    return YES;    /* Equally long equal strings */
    else if ('*' == *p) {        /* Wildcard */
    p++;                /* Skip wildcard character */
    m = strlen(q) - strlen(p);    /* Amount to match to wildcard */
    if (m < 0) return NO;        /* No match, filename too short */
    else {            /* Skip the matched characters and compare */
        if (strcmp(p, q+m))    return NO;    /* Tail mismatch */
        else                return YES;    /* Tail match */
    }
    }    /* if wildcard */
    else        return NO;    /* Length or character mismatch */
}


/* PUBLIC                        HTAA_templateCaseMatch()
**        STRING COMPARISON FUNCTION FOR FILE NAMES
**           WITH ONE WILDCARD * IN THE TEMPLATE (Case Insensitive)
** NOTE:
**    This is essentially the same code as in HTAA_templateMatch, but
**    it compares case insensitive (for VMS). Reason for this routine
**    is that HTAA_templateMatch gets called from several places, also
**    there where a case sensitive match is needed, so one cannot just
**    change the HTAA_templateMatch routine for VMS.
**
** ON ENTRY:
**    template    is a template string to match the file name
**            agaist, may contain a single wildcard
**            character * which matches zero or more
**            arbitrary characters.
**    filename    is the filename (or pathname) to be matched
**            agaist the template.
**
** ON EXIT:
**    returns        YES, if filename matches the template.
**            NO, otherwise.
*/
PUBLIC BOOL HTAA_templateCaseMatch ARGS2(CONST char *, template,
                         CONST char *, filename)
{
    CONST char *p = template;
    CONST char *q = filename;
    int m;

    for( ; *p  &&  *q  &&  toupper(*p) == toupper(*q); p++, q++) /* Find first mismatch */
    ; /* do nothing else */

    if (!*p && !*q)    return YES;    /* Equally long equal strings */
    else if ('*' == *p) {        /* Wildcard */
    p++;                /* Skip wildcard character */
    m = strlen(q) - strlen(p);    /* Amount to match to wildcard */
    if (m < 0) return NO;        /* No match, filename too short */
    else {            /* Skip the matched characters and compare */
        if (strcasecomp(p, q+m))    return NO;    /* Tail mismatch */
        else                return YES;    /* Tail match */
    }
    }    /* if wildcard */
    else        return NO;    /* Length or character mismatch */
}


/* PUBLIC                    HTAA_makeProtectionTemplate()
**        CREATE A PROTECTION TEMPLATE FOR THE FILES
**        IN THE SAME DIRECTORY AS THE GIVEN FILE
**        (Used by server if there is no fancier way for
**        it to tell the client, and by browser if server
**        didn't send WWW-ProtectionTemplate: field)
** ON ENTRY:
**    docname    is the document pathname (from URL).
**
** ON EXIT:
**    returns    a template matching docname, and other files
**        files in that directory.
**
**        E.g.  /foo/bar/x.html  =>  /foo/bar/ *
**                            ^
**                Space only to prevent it from
**                being a comment marker here,
**                there really isn't any space.
*/
PUBLIC char *HTAA_makeProtectionTemplate ARGS1(CONST char *, docname)
{
    char *template = NULL;
    char *slash = NULL;

    if (docname) {
    StrAllocCopy(template, docname);
    slash = strrchr(template, '/');
    if (slash) slash++;
    else slash = template;
    *slash = (char)0;
    StrAllocCat(template, "*");
    }
    else StrAllocCopy(template, "*");
#ifndef RELEASE
    if (TRACE) fprintf(stderr,
               "make_template: made template `%s' for file `%s'\n",
               template, docname);
#endif /* RELEASE */

    return template;
}




/*
** Skip leading whitespace from *s forward
*/
#define SKIPWS(s) while (*s==' ' || *s=='\t') s++;

/*
** Kill trailing whitespace starting from *(s-1) backwords
*/
#define KILLWS(s) {char *c=s-1; while (*c==' ' || *c=='\t') *(c--)=(char)0;}


/* PUBLIC                        HTAA_parseArgList()
**        PARSE AN ARGUMENT LIST GIVEN IN A HEADER FIELD
** ON ENTRY:
**    str    is a comma-separated list:
**
**            item, item, item
**        where
**            item ::= value
**                   | name=value
**                   | name="value"
**
**        Leading and trailing whitespace is ignored
**        everywhere except inside quotes, so the following
**        examples are equal:
**
**            name=value,foo=bar
**             name="value",foo="bar"
**              name = value ,  foo = bar
**               name = "value" ,  foo = "bar"
**
** ON EXIT:
**    returns    a list of name-value pairs (actually HTAssocList*).
**        For items with no name, just value, the name is
**        the number of order number of that item. E.g.
**        "1" for the first, etc.
*/
PUBLIC HTAssocList *HTAA_parseArgList ARGS1(char *, str)
{
    HTAssocList *assoc_list = HTAssocList_new();
    char *cur = NULL;
    char *name = NULL;
    int index = 0;

    if (!str) return assoc_list;

    while (*str) {
    SKIPWS(str);                /* Skip leading whitespace */
    cur = str;
    index++;

    while (*cur  &&  *cur != '='  &&  *cur != ',')
        cur++;    /* Find end of name (or lonely value without a name) */
    KILLWS(cur);    /* Kill trailing whitespace */

    if (*cur == '=') {            /* Name followed by a value */
        *(cur++) = (char)0;            /* Terminate name */
        StrAllocCopy(name, str);
        SKIPWS(cur);            /* Skip WS leading the value */
        str = cur;
        if (*str == '"') {            /* Quoted value */
        str++;
        cur = str;
        while (*cur  &&  *cur != '"') cur++;
        if (*cur == '"')
            *(cur++) = (char)0;    /* Terminate value */
        /* else it is lacking terminating quote */
        SKIPWS(cur);            /* Skip WS leading comma */
        if (*cur == ',') cur++;        /* Skip separating colon */
        }
        else {                /* Unquoted value */
        while (*cur  &&  *cur != ',') cur++;
        KILLWS(cur);            /* Kill trailing whitespace */
        if (*cur == ',')
            *(cur++) = (char)0;
        /* else *cur already NULL */
        }
    }
    else {    /* No name, just a value */
        if (*cur == ',')
        *(cur++) = (char)0;        /* Terminate value */
        /* else last value on line (already terminated by NULL) */
        StrAllocCopy(name, "nnn");    /* Room for item order number */
        sprintf(name, "%d", index); /* Item order number for name */
    }
    HTAssocList_add(assoc_list, name, str);
    str = cur;
    } /* while *str */

    return assoc_list;
}



/************** HEADER LINE READER -- DOES UNFOLDING *************************/

#define BUFFER_SIZE    1024

PRIVATE char buffer[BUFFER_SIZE + 1];
PRIVATE char *start_pointer = buffer;
PRIVATE char *end_pointer = buffer;
PRIVATE int in_soc = -1;

/* PUBLIC                        HTAA_setupReader()
**        SET UP HEADER LINE READER, i.e. give
**        the already-read-but-not-yet-processed
**        buffer of text to be read before more
**        is read from the socket.
** ON ENTRY:
**    start_of_headers is a pointer to a buffer containing
**            the beginning of the header lines
**            (rest will be read from a socket).
**    length        is the number of valid characters in
**            'start_of_headers' buffer.
**    soc        is the socket to use when start_of_headers
**            buffer is used up.
** ON EXIT:
**    returns        nothing.
**            Subsequent calls to HTAA_getUnfoldedLine()
**            will use this buffer first and then
**            proceed to read from socket.
*/
PUBLIC void HTAA_setupReader ARGS3(char *,    start_of_headers,
                   int,        length,
                   int,        soc)
{
    start_pointer = buffer;
    if (start_of_headers) {
    strncpy(buffer, start_of_headers, length);
    buffer[length] = (char)0;
    end_pointer = buffer + length;
    }
    else {
    *start_pointer = (char)0;
    end_pointer = start_pointer;
    }
    in_soc = soc;
}


/* PUBLIC                        HTAA_getUnfoldedLine()
**        READ AN UNFOLDED HEADER LINE FROM SOCKET
** ON ENTRY:
**    HTAA_setupReader must absolutely be called before
**    this function to set up internal buffer.
**
** ON EXIT:
**    returns    a newly-allocated character string representing
**        the read line.  The line is unfolded, i.e.
**        lines that begin with whitespace are appended
**        to current line.  E.g.
**
**            Field-Name: Blaa-Blaa
**             This-Is-A-Continuation-Line
**             Here-Is_Another
**
**        is seen by the caller as:
**
**    Field-Name: Blaa-Blaa This-Is-A-Continuation-Line Here-Is_Another
**
*/
PUBLIC char *HTAA_getUnfoldedLine NOARGS
{
    char *line = NULL;
    char *cur;
    int count;
    BOOL peek_for_folding = NO;

    if (in_soc < 0) {
    fprintf(stderr, "%s %s\n",
        "HTAA_getUnfoldedLine: buffer not initialized",
        "with function HTAA_setupReader()");
    return NULL;
    }

    for(;;) {

    /* Reading from socket */

    if (start_pointer >= end_pointer) {/*Read the next block and continue*/
        count = NETREAD(in_soc, buffer, BUFFER_SIZE);
        if (count <= 0) {
        in_soc = -1;
        return line;
        }
        start_pointer = buffer;
        end_pointer = buffer + count;
        *end_pointer = (char)0;
#ifdef NOT_ASCII
        cur = start_pointer;
        while (cur < end_pointer) {
        *cur = TOASCII(*cur);
        cur++;
        }
#endif /*NOT_ASCII*/
    }
    cur = start_pointer;


    /* Unfolding */

    if (peek_for_folding) {
        if (*cur != ' '  &&  *cur != '\t')
        return line;    /* Ok, no continuation line */
        else        /* So this is a continuation line, continue */
        peek_for_folding = NO;
    }


    /* Finding end-of-line */

    while (cur < end_pointer && *cur != '\n') /* Find the end-of-line */
        cur++;                  /* (or end-of-buffer).  */


    /* Terminating line */

    if (cur < end_pointer) {    /* So *cur==LF, terminate line */
        *cur = (char)0;        /* Overwrite LF */
        if (*(cur-1) == '\r')
        *(cur-1) = (char)0;    /* Overwrite CR */
        peek_for_folding = YES;    /* Check for a continuation line */
    }


    /* Copying the result */

    if (line)
        StrAllocCat(line, start_pointer);    /* Append */
    else
        StrAllocCopy(line, start_pointer);    /* A new line */

    start_pointer = cur+1;    /* Skip the read line */

    } /* forever */
}