X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/627d1a1b61d9c535835221afcbe1b9cd6548cd3b..41313d92e0f157dacfa758993e7fc76e291b0415:/src/src/mime.c diff --git a/src/src/mime.c b/src/src/mime.c index 6bffa7897..0339295f3 100644 --- a/src/src/mime.c +++ b/src/src/mime.c @@ -2,8 +2,10 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) Tom Kistner 2004 */ -/* License: GPL */ +/* Copyright (c) Tom Kistner 2004, 2015 + * License: GPL + * Copyright (c) The Exim Maintainers 2016 + */ #include "exim.h" #ifdef WITH_CONTENT_SCAN /* entire file */ @@ -13,19 +15,43 @@ FILE *mime_stream = NULL; uschar *mime_current_boundary = NULL; +static mime_header mime_header_list[] = { + { US"content-type:", 13, &mime_content_type }, + { US"content-disposition:", 20, &mime_content_disposition }, + { US"content-transfer-encoding:", 26, &mime_content_transfer_encoding }, + { US"content-id:", 11, &mime_content_id }, + { US"content-description:", 20, &mime_content_description } +}; + +static int mime_header_list_size = nelem(mime_header_list); + +static mime_parameter mime_parameter_list[] = { + { US"name=", 5, &mime_filename }, + { US"filename=", 9, &mime_filename }, + { US"charset=", 8, &mime_charset }, + { US"boundary=", 9, &mime_boundary } +}; + + /************************************************* * set MIME anomaly level + text * *************************************************/ /* Small wrapper to set the two expandables which give info on detected "problems" in MIME - encodings. Those are defined in mime.h. */ + encodings. Indexes are defined in mime.h. */ -static void -mime_set_anomaly(int level, const char *text) +void +mime_set_anomaly(int idx) { - mime_anomaly_level = level; - mime_anomaly_text = CUS text; +struct anom { + int level; + const uschar * text; +} anom[] = { {1, CUS"Broken Quoted-Printable encoding detected"}, + {2, CUS"Broken BASE64 encoding detected"} }; + +mime_anomaly_level = anom[idx].level; +mime_anomaly_text = anom[idx].text; } @@ -99,84 +125,6 @@ mime_decode_asis(FILE* in, FILE* out, uschar* boundary) } -/* decode base64 MIME part */ -static ssize_t -mime_decode_base64(FILE* in, FILE* out, uschar* boundary) -{ - uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH]; - uschar *ipos, *opos; - ssize_t len, size = 0; - int bytestate = 0; - - opos = obuf; - - while (Ufgets(ibuf, MIME_MAX_LINE_LENGTH, in) != NULL) - { - if (boundary != NULL - && Ustrncmp(ibuf, "--", 2) == 0 - && Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0 - ) - break; - - for (ipos = ibuf ; *ipos != '\r' && *ipos != '\n' && *ipos != 0; ++ipos) - { - if (*ipos == '=') /* skip padding */ - { - ++bytestate; - continue; - } - if (mime_b64[*ipos] == 128) /* skip bad characters */ - { - mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64); - continue; - } - - /* simple state-machine */ - switch((bytestate++) & 3) - { - case 0: - *opos = mime_b64[*ipos] << 2; - break; - case 1: - *opos |= mime_b64[*ipos] >> 4; - ++opos; - *opos = mime_b64[*ipos] << 4; - break; - case 2: - *opos |= mime_b64[*ipos] >> 2; - ++opos; - *opos = mime_b64[*ipos] << 6; - break; - case 3: - *opos |= mime_b64[*ipos]; - ++opos; - break; - } /* switch */ - } /* for */ - - /* something to write? */ - len = opos - obuf; - if (len > 0) - { - if (fwrite(obuf, 1, len, out) != len) return -1; /* error */ - size += len; - /* copy incomplete last byte to start of obuf, where we continue */ - if ((bytestate & 3) != 0) - *obuf = *opos; - opos = obuf; - } - } /* while */ - - /* write out last byte if it was incomplete */ - if (bytestate & 3) - { - if (fwrite(obuf, 1, 1, out) != 1) return -1; - ++size; - } - - return size; -} - /* decode quoted-printable MIME part */ static ssize_t @@ -358,7 +306,8 @@ decode_function = size_counter = decode_function(mime_stream, decode_file, mime_current_boundary); clearerr(mime_stream); -fseek(mime_stream, f_pos, SEEK_SET); +if (fseek(mime_stream, f_pos, SEEK_SET)) + return DEFER; if (fclose(decode_file) != 0 || size_counter < 0) return DEFER; @@ -516,11 +465,11 @@ while (*s && *s != ';') /* ; terminates */ { s++; /* skip opening " */ while (*s && *s != '"') /* " protects ; */ - val = string_cat(val, &size, &ptr, s++, 1); + val = string_catn(val, &size, &ptr, s++, 1); if (*s) s++; /* skip closing " */ } else - val = string_cat(val, &size, &ptr, s++, 1); + val = string_catn(val, &size, &ptr, s++, 1); if (val) val[ptr] = '\0'; *sp = s; return val; @@ -547,23 +496,24 @@ static uschar * rfc2231_to_2047(const uschar * fname, const uschar * charset, int * len) { int size = 0, ptr = 0; -uschar * val = string_cat(NULL, &size, &ptr, US"=?", 2); +uschar * val = string_catn(NULL, &size, &ptr, US"=?", 2); uschar c; -val = string_cat(val, &size, &ptr, charset, Ustrlen(charset)); -val = string_cat(val, &size, &ptr, US"?Q?", 3); +if (charset) + val = string_cat(val, &size, &ptr, charset); +val = string_catn(val, &size, &ptr, US"?Q?", 3); while ((c = *fname)) if (c == '%' && isxdigit(fname[1]) && isxdigit(fname[2])) { - val = string_cat(val, &size, &ptr, US"=", 1); - val = string_cat(val, &size, &ptr, ++fname, 2); + val = string_catn(val, &size, &ptr, US"=", 1); + val = string_catn(val, &size, &ptr, ++fname, 2); fname += 2; } else - val = string_cat(val, &size, &ptr, fname++, 1); + val = string_catn(val, &size, &ptr, fname++, 1); -val = string_cat(val, &size, &ptr, US"?=", 2); +val = string_catn(val, &size, &ptr, US"?=", 2); val[*len = ptr] = '\0'; return val; } @@ -607,7 +557,7 @@ while(1) if (!fgets(CS header, MIME_MAX_HEADER_SIZE, f)) { /* Hit EOF or read error. Ugh. */ - DEBUG(D_acl) debug_printf("Hit EOF ...\n"); + DEBUG(D_acl) debug_printf("MIME: Hit EOF ...\n"); return rc; } @@ -619,12 +569,12 @@ while(1) if (Ustrncmp((header+2+Ustrlen(context->boundary)), "--", 2) == 0) { /* END boundary found */ - DEBUG(D_acl) debug_printf("End boundary found %s\n", + DEBUG(D_acl) debug_printf("MIME: End boundary found %s\n", context->boundary); return rc; } - DEBUG(D_acl) debug_printf("Next part with boundary %s\n", + DEBUG(D_acl) debug_printf("MIME: Next part with boundary %s\n", context->boundary); break; } @@ -640,8 +590,6 @@ while(1) mh < mime_header_list + mime_header_list_size; mh++) if (strncmpic(mh->name, header, mh->namelen) == 0) { - uschar * header_value = NULL; - int header_value_len = 0; uschar * p = header + mh->namelen; uschar * q; @@ -650,7 +598,7 @@ while(1) for (q = p; *q != ';' && *q; q++) ; *mh->value = string_copynlc(p, q-p); - DEBUG(D_acl) debug_printf("found %s MIME header, value is '%s'\n", + DEBUG(D_acl) debug_printf("MIME: found %s header, value is '%s'\n", mh->name, *mh->value); if (*(p = q)) p++; /* jump past the ; */ @@ -668,11 +616,11 @@ while(1) { mime_parameter * mp; - DEBUG(D_acl) debug_printf(" considering paramlist '%s'\n", p); + DEBUG(D_acl) debug_printf("MIME: considering paramlist '%s'\n", p); if ( !mime_filename - && strncmpic("content-disposition:", header, 20) == 0 - && strncmpic("filename*", p, 9) == 0 + && strncmpic(CUS"content-disposition:", header, 20) == 0 + && strncmpic(CUS"filename*", p, 9) == 0 ) { /* RFC 2231 filename */ uschar * q; @@ -702,22 +650,27 @@ while(1) uschar * s = q; /* look for a ' in the "filename" */ - while(*s != '\'' && *s) s++; /* s is ' or NUL */ + while(*s != '\'' && *s) s++; /* s is 1st ' or NUL */ if ((size = s-q) > 0) - { mime_filename_charset = string_copyn(q, size); - p = s; - while(*p == '\'' && *p) p++; /* p is after ' */ - } + if (*(p = s)) p++; + while(*p == '\'') p++; /* p is after 2nd ' */ } else p = q; + DEBUG(D_acl) debug_printf("MIME: charset %s fname '%s'\n", + mime_filename_charset ? mime_filename_charset : US"", p); + temp_string = rfc2231_to_2047(p, mime_filename_charset, &slen); - temp_string = rfc2047_decode(temp_string, FALSE, NULL, 32, + DEBUG(D_acl) debug_printf("MIME: 2047-name %s\n", temp_string); + + temp_string = rfc2047_decode(temp_string, FALSE, NULL, ' ', NULL, &err_msg); + DEBUG(D_acl) debug_printf("MIME: plain-name %s\n", temp_string); + size = Ustrlen(temp_string); if (size == slen) @@ -752,7 +705,7 @@ while(1) &dummy_errstr) : NULL; DEBUG(D_acl) debug_printf( - " found %s MIME parameter in %s header, value '%s'\n", + "MIME: found %s parameter in %s header, value '%s'\n", mp->name, mh->name, *mp->value); break; /* done matching param names */ @@ -765,12 +718,12 @@ while(1) if (*p) p++; } /* param scan on line */ - if (strncmpic("content-disposition:", header, 20) == 0) + if (strncmpic(CUS"content-disposition:", header, 20) == 0) { if (decoding_failed) mime_filename = mime_fname_rfc2231; DEBUG(D_acl) debug_printf( - " found %s MIME parameter in %s header, value is '%s'\n", + "MIME: found %s parameter in %s header, value is '%s'\n", "filename", mh->name, mime_filename); } } @@ -811,8 +764,9 @@ while(1) (nested_context.boundary != NULL) && (Ustrncmp(mime_content_type,"multipart",9) == 0) ) { - DEBUG(D_acl) debug_printf("Entering multipart recursion, boundary '%s'\n", - nested_context.boundary); + DEBUG(D_acl) + debug_printf("MIME: Entering multipart recursion, boundary '%s'\n", + nested_context.boundary); nested_context.context = context && context->context == MBC_ATTACHMENT