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/* rfc822valid.c -- validators for RFC-822 syntax |
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* (C) Copyright 2007 Matthias Andree <matthias.andree@gmx.de> |
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* GNU General Public License v2 */ |
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|
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/* This works only on ASCII-based computers. */ |
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|
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#include "fetchmail.h" |
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#include <string.h> |
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|
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/* CHAR except specials, SPACE, CTLs */ |
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static const char *atomchar = "!#$%&'*+-/0123456789=?ABCDEFGHIJKLMNOPQRSTUVWXYZ^_`abcdefghijklmnopqrstuvwxyz{|}~"; |
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|
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static int quotedpair(unsigned char const **x) { |
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if (**x != '\\') return 0; |
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++ *x; |
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if ((int)* *x > 127 || * *x == '\0') |
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/* XXX FIXME: 0 is a legal CHAR, so the == '\0' is sort of bogus |
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* above, but fetchmail does not currently deal with NUL inputs |
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* so we don't need to make the distinction between |
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* end-of-string and quoted NUL. */ |
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return 0; |
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++ *x; |
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return 1; |
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} |
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|
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|
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static int quotedstring(unsigned char const **x) { |
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if (* *x != '"') return 0; |
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++ *x; |
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for(;;) { |
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switch (* *x) { |
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case '"': |
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++ *x; |
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return 1; |
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case '\\': |
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if (quotedpair(x) == 0) return 0; |
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continue; |
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case '\r': |
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case '\0': |
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return 0; |
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} |
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if ((int)* *x >= 128) { |
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return 0; |
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} |
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++ *x; |
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} |
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} |
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|
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static int atom(unsigned char const **x) { |
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/* atom */ |
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if (strchr(atomchar, (char)**x)) { |
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*x += strspn((const char *)*x, atomchar); |
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return 1; |
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} |
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/* invalid character */ |
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return 0; |
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} |
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|
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static int word(unsigned char const **x) { |
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if (**x == '"') |
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return quotedstring(x); |
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return atom(x); |
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} |
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|
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static int domain_literal(unsigned char const **x) { |
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if (**x != '[') return 0; |
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++ *x; |
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for(;;) { |
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switch (* *x) { |
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case '\0': |
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case '\r': |
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case '[': |
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return 0; |
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case ']': |
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++ *x; |
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return 1; |
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case '\\': |
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if (quotedpair(x) == 0) return 0; |
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continue; |
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} |
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if ((int)* *x > 127) return 0; |
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++ *x; |
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} |
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} |
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|
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static int subdomain(unsigned char const **x) { |
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if (* *x == '[') return domain_literal(x); |
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return atom(x); |
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} |
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|
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int rfc822_valid_msgid(const unsigned char *x) { |
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/* expect "<" */ |
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if (*x != '<') return 0; |
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++ x; |
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|
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/* expect local-part = word *("." word) |
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* where |
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* word = atom/quoted-string |
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* atom = 1*ATOMCHAR |
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* quoted-string = <"> *(qtext/quoted-pair) <"> |
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* qtext = CHAR except ", \, CR |
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* quoted-pair = "\" CHAR |
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*/ |
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for(;;) { |
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if (word(&x) == 0) return 0; |
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if (*x == '.') { ++x; continue; } |
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if (*x == '@') break; |
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return 0; |
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} |
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|
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/* expect "@" */ |
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if (*x != '@') return 0; |
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++ x; |
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|
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/* expect domain = sub-domain *("." sub-domain) |
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* sub-domain = domain-ref/domain-literal |
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* domain-ref = atom |
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* domain-literal = "[" *(dtext/quoted-pair) "]" */ |
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for(;;) { |
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if (subdomain(&x) == 0) return 0; |
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if (*x == '.') { ++x; continue; } |
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if (*x == '>') break; |
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return 0; |
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} |
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|
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if (*x != '>') return 0; |
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return 1; |
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} |
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|
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#ifdef TEST |
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#include <stdio.h> |
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|
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int main(int argc, char **argv) { |
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int i; |
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for (i = 1; i < argc; i++) { |
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printf("%s: %s\n", argv[i], rfc822_valid_msgid((unsigned char *)argv[i]) ? "OK" : "INVALID"); |
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} |
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return 0; |
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} |
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#endif |
