src/message_api.c
author Edouard Tisserant
Thu, 17 Mar 2016 00:02:25 +0100
changeset 510 fa26f8ffe06b
parent 507 288496838ffb
child 539 c8a4c7b86064
child 545 5b4ecbfa3ac8
permissions -rw-r--r--
Ensure that message is no encrypted when one recipient's key is mistrusted or under_attack
     1 #include "pEp_internal.h"
     2 #include "message_api.h"
     3 
     4 #include "platform.h"
     5 #include "mime.h"
     6 
     7 #include <assert.h>
     8 #include <string.h>
     9 #include <stdlib.h>
    10 
    11 #ifndef MIN
    12 #define MIN(A, B) ((B) > (A) ? (A) : (B))
    13 #endif
    14 #ifndef MAX
    15 #define MAX(A, B) ((B) > (A) ? (B) : (A))
    16 #endif
    17 
    18 
    19 static bool string_equality(const char *s1, const char *s2)
    20 {
    21     if (s1 == NULL || s2 == NULL)
    22         return false;
    23 
    24     assert(s1 && s2);
    25 
    26     return strcmp(s1, s2) == 0;
    27 }
    28 
    29 static bool is_mime_type(const bloblist_t *bl, const char *mt)
    30 {
    31     assert(mt);
    32 
    33     return bl && string_equality(bl->mime_type, mt);
    34 }
    35 
    36 static bool is_fileending(const bloblist_t *bl, const char *fe)
    37 {
    38     assert(fe);
    39 
    40     if (bl == NULL || bl->filename == NULL)
    41         return false;
    42 
    43     assert(bl && bl->filename);
    44 
    45     size_t fe_len = strlen(fe);
    46     size_t fn_len = strlen(bl->filename);
    47 
    48     if (fn_len <= fe_len)
    49         return false;
    50 
    51     assert(fn_len > fe_len);
    52 
    53     return strcmp(bl->filename + (fn_len - fe_len), fe) == 0;
    54 }
    55 
    56 static void add_opt_field(message *msg, const char *name, const char *value)
    57 {
    58     assert(msg);
    59 
    60     if (msg && name && value) {
    61         stringpair_t *pair = new_stringpair(name, value);
    62         if (pair == NULL)
    63             return;
    64 
    65         stringpair_list_t *field = stringpair_list_add(msg->opt_fields, pair);
    66         if (field == NULL)
    67             return;
    68 
    69         if (msg->opt_fields == NULL)
    70             msg->opt_fields = field;
    71     }
    72 }
    73 
    74 static char * combine_short_and_long(const char *shortmsg, const char *longmsg)
    75 {
    76     char * ptext;
    77 
    78     assert(shortmsg);
    79     assert(strcmp(shortmsg, "pEp") != 0);
    80 
    81     if (longmsg == NULL)
    82         longmsg = "";
    83 
    84     ptext = calloc(1, strlen(shortmsg) + strlen(longmsg) + 12);
    85     assert(ptext);
    86     if (ptext == NULL)
    87         return NULL;
    88 
    89     strcpy(ptext, "Subject: ");
    90     strcat(ptext, shortmsg);
    91     strcat(ptext, "\n\n");
    92     strcat(ptext, longmsg);
    93 
    94     return ptext;
    95 }
    96 
    97 static int seperate_short_and_long(const char *src, char **shortmsg, char **longmsg)
    98 {
    99     char *_shortmsg = NULL;
   100     char *_longmsg = NULL;
   101 
   102     assert(src);
   103     assert(shortmsg);
   104     assert(longmsg);
   105 
   106     *shortmsg = NULL;
   107     *longmsg = NULL;
   108 
   109     if (strncasecmp(src, "subject: ", 9) == 0) {
   110         char *line_end = strchr(src, '\n');
   111 
   112         if (line_end == NULL) {
   113             _shortmsg = strdup(src + 9);
   114             assert(_shortmsg);
   115             if (_shortmsg == NULL)
   116                 goto enomem;
   117             // _longmsg = NULL;
   118         }
   119         else {
   120             size_t n = line_end - src;
   121 
   122             if (*(line_end - 1) == '\r')
   123                 _shortmsg = strndup(src + 9, n - 10);
   124             else
   125                 _shortmsg = strndup(src + 9, n - 9);
   126             assert(_shortmsg);
   127             if (_shortmsg == NULL)
   128                 goto enomem;
   129 
   130             while (*(src + n) && (*(src + n) == '\n' || *(src + n) == '\r'))
   131                 ++n;
   132 
   133             if (*(src + n)) {
   134                 _longmsg = strdup(src + n);
   135                 assert(_longmsg);
   136                 if (_longmsg == NULL)
   137                     goto enomem;
   138             }
   139         }
   140     }
   141     else {
   142         _shortmsg = strdup("");
   143         assert(_shortmsg);
   144         if (_shortmsg == NULL)
   145             goto enomem;
   146         _longmsg = strdup(src);
   147         assert(_longmsg);
   148         if (_longmsg == NULL)
   149             goto enomem;
   150     }
   151 
   152     *shortmsg = _shortmsg;
   153     *longmsg = _longmsg;
   154 
   155     return 0;
   156 
   157 enomem:
   158     free(_shortmsg);
   159     free(_longmsg);
   160 
   161     return -1;
   162 }
   163 
   164 static PEP_STATUS copy_fields(message *dst, const message *src)
   165 {
   166     assert(dst);
   167     assert(src);
   168 
   169     free_timestamp(dst->sent);
   170     dst->sent = NULL;
   171     if (src->sent) {
   172         dst->sent = timestamp_dup(src->sent);
   173         if (dst->sent == NULL)
   174             return PEP_OUT_OF_MEMORY;
   175     }
   176 
   177     free_timestamp(dst->recv);
   178     dst->recv = NULL;
   179     if (src->recv) {
   180         dst->recv = timestamp_dup(src->recv);
   181         if (dst->recv == NULL)
   182             return PEP_OUT_OF_MEMORY;
   183     }
   184 
   185     free_identity(dst->from);
   186     dst->from = NULL;
   187     if (src->from) {
   188         dst->from = identity_dup(src->from);
   189         if (dst->from == NULL)
   190             return PEP_OUT_OF_MEMORY;
   191     }
   192 
   193     free_identity_list(dst->to);
   194     dst->to = NULL;
   195     if (src->to && src->to->ident) {
   196         dst->to = identity_list_dup(src->to);
   197         if (dst->to == NULL)
   198             return PEP_OUT_OF_MEMORY;
   199     }
   200 
   201     free_identity(dst->recv_by);
   202     dst->recv_by = NULL;
   203     if (src->recv_by) {
   204         dst->recv_by = identity_dup(src->recv_by);
   205         if (dst->recv_by == NULL)
   206             return PEP_OUT_OF_MEMORY;
   207     }
   208 
   209     free_identity_list(dst->cc);
   210     dst->cc = NULL;
   211     if (src->cc && src->cc->ident) {
   212         dst->cc = identity_list_dup(src->cc);
   213         if (dst->cc == NULL)
   214             return PEP_OUT_OF_MEMORY;
   215     }
   216 
   217     free_identity_list(dst->bcc);
   218     dst->bcc = NULL;
   219     if (src->bcc && src->bcc->ident) {
   220         dst->bcc = identity_list_dup(src->bcc);
   221         if (dst->bcc == NULL)
   222             return PEP_OUT_OF_MEMORY;
   223     }
   224 
   225     free_identity_list(dst->reply_to);
   226     dst->reply_to = NULL;
   227     if (src->reply_to && src->reply_to->ident) {
   228         dst->reply_to = identity_list_dup(src->reply_to);
   229         if (dst->reply_to == NULL)
   230             return PEP_OUT_OF_MEMORY;
   231     }
   232 
   233     free_stringlist(dst->in_reply_to);
   234     dst->in_reply_to = NULL;
   235     if (src->in_reply_to && src->in_reply_to->value) {
   236         dst->in_reply_to = stringlist_dup(src->in_reply_to);
   237         if (dst->in_reply_to == NULL)
   238             return PEP_OUT_OF_MEMORY;
   239     }
   240 
   241     free_stringlist(dst->references);
   242     dst->references = NULL;
   243     if (src->references) {
   244         dst->references = stringlist_dup(src->references);
   245         if (dst->references == NULL)
   246             return PEP_OUT_OF_MEMORY;
   247     }
   248 
   249     free_stringlist(dst->keywords);
   250     dst->keywords = NULL;
   251     if (src->keywords && src->keywords->value) {
   252         dst->keywords = stringlist_dup(src->keywords);
   253         if (dst->keywords == NULL)
   254             return PEP_OUT_OF_MEMORY;
   255     }
   256 
   257     free(dst->comments);
   258     dst->comments = NULL;
   259     if (src->comments) {
   260         dst->comments = strdup(src->comments);
   261         assert(dst->comments);
   262         if (dst->comments == NULL)
   263             return PEP_OUT_OF_MEMORY;
   264     }
   265 
   266     return PEP_STATUS_OK;
   267 }
   268 
   269 static message * clone_to_empty_message(const message * src)
   270 {
   271     PEP_STATUS status;
   272     message * msg = NULL;
   273 
   274     assert(src);
   275 
   276     msg = calloc(1, sizeof(message));
   277     assert(msg);
   278     if (msg == NULL)
   279         goto enomem;
   280 
   281     msg->dir = src->dir;
   282 
   283     status = copy_fields(msg, src);
   284     if (status != PEP_STATUS_OK)
   285         goto enomem;
   286 
   287     return msg;
   288 
   289 enomem:
   290     free_message(msg);
   291     return NULL;
   292 }
   293 
   294 static PEP_STATUS encrypt_PGP_MIME(
   295     PEP_SESSION session,
   296     const message *src,
   297     stringlist_t *keys,
   298     message *dst
   299     )
   300 {
   301     PEP_STATUS status = PEP_STATUS_OK;
   302     bool free_ptext = false;
   303     char *ptext = NULL;
   304     char *ctext;
   305     char *_ctext = NULL;
   306     char *mimetext = NULL;
   307     size_t csize;
   308     assert(dst->longmsg == NULL);
   309     dst->enc_format = PEP_enc_PGP_MIME;
   310 
   311     if (src->shortmsg && strcmp(src->shortmsg, "pEp") != 0) {
   312         if (session->unencrypted_subject) {
   313             dst->shortmsg = strdup(src->shortmsg);
   314             assert(dst->shortmsg);
   315             if (dst->shortmsg == NULL)
   316                 goto enomem;
   317             ptext = src->longmsg;
   318         }
   319         else {
   320             ptext = combine_short_and_long(src->shortmsg, src->longmsg);
   321             if (ptext == NULL)
   322                 goto enomem;
   323             free_ptext = true;
   324         }
   325     }
   326     else if (src->longmsg) {
   327         ptext = src->longmsg;
   328     }
   329     else {
   330         ptext = "pEp";
   331     }
   332 
   333     message *_src = calloc(1, sizeof(message));
   334     assert(_src);
   335     if (_src == NULL)
   336         goto enomem;
   337     _src->longmsg = ptext;
   338     _src->longmsg_formatted = src->longmsg_formatted;
   339     _src->attachments = src->attachments;
   340     _src->enc_format = PEP_enc_none;
   341     status = mime_encode_message(_src, true, &mimetext);
   342     assert(status == PEP_STATUS_OK);
   343     if (free_ptext){
   344         free(ptext);
   345         free_ptext=0;
   346     }
   347     free(_src);
   348     assert(mimetext);
   349     if (mimetext == NULL)
   350         goto pep_error;
   351 
   352     status = encrypt_and_sign(session, keys, mimetext, strlen(mimetext),
   353         &ctext, &csize);
   354     free(mimetext);
   355     if (ctext == NULL)
   356         goto pep_error;
   357 
   358     dst->longmsg = strdup("this message was encrypted with p≡p "
   359         "https://pEp-project.org");
   360     assert(dst->longmsg);
   361     if (dst->longmsg == NULL)
   362         goto enomem;
   363 
   364     char *v = strdup("Version: 1");
   365     assert(v);
   366     if (v == NULL)
   367         goto enomem;
   368 
   369     bloblist_t *_a = new_bloblist(v, 11, "application/pgp-encrypted", NULL);
   370     if (_a == NULL)
   371         goto enomem;
   372     dst->attachments = _a;
   373 
   374     _ctext = malloc(csize);
   375     assert(_ctext);
   376     if (_ctext == NULL)
   377         goto enomem;
   378     memcpy(_ctext, ctext, csize);
   379 
   380     _a = bloblist_add(_a, _ctext, csize, "application/octet-stream",
   381         "msg.asc");
   382     if (_a == NULL)
   383         goto enomem;
   384 
   385     return PEP_STATUS_OK;
   386 
   387 enomem:
   388     status = PEP_OUT_OF_MEMORY;
   389 
   390 pep_error:
   391     if (free_ptext)
   392         free(ptext);
   393     free(_ctext);
   394     return status;
   395 }
   396 
   397 static PEP_STATUS encrypt_PGP_in_pieces(
   398     PEP_SESSION session,
   399     const message *src,
   400     stringlist_t *keys,
   401     message *dst
   402     )
   403 {
   404     PEP_STATUS status = PEP_STATUS_OK;
   405     char *ctext;
   406     size_t csize;
   407     char *ptext = NULL;
   408     bool free_ptext = false;
   409 
   410     assert(dst->longmsg == NULL);
   411     assert(dst->attachments == NULL);
   412 
   413     dst->enc_format = PEP_enc_pieces;
   414 
   415     if (src->shortmsg && src->shortmsg[0] && strcmp(src->shortmsg, "pEp") != 0) {
   416         if (session->unencrypted_subject) {
   417             dst->shortmsg = strdup(src->shortmsg);
   418             assert(dst->shortmsg);
   419             if (dst->shortmsg == NULL)
   420                 goto enomem;
   421             ptext = src->longmsg;
   422         }
   423         else {
   424             ptext = combine_short_and_long(src->shortmsg, src->longmsg);
   425             if (ptext == NULL)
   426                 goto enomem;
   427             free_ptext = true;
   428         }
   429 
   430         status = encrypt_and_sign(session, keys, ptext, strlen(ptext), &ctext,
   431             &csize);
   432         if (free_ptext)
   433             free(ptext);
   434         free_ptext = false;
   435         if (ctext) {
   436             dst->longmsg = strndup(ctext, csize);
   437             assert(dst->longmsg);
   438             if (dst->longmsg == NULL)
   439                 goto enomem;
   440         }
   441         else {
   442             goto pep_error;
   443         }
   444     }
   445     else if (src->longmsg && src->longmsg[0]) {
   446         ptext = src->longmsg;
   447         status = encrypt_and_sign(session, keys, ptext, strlen(ptext), &ctext,
   448             &csize);
   449         if (ctext) {
   450             dst->longmsg = strndup(ctext, csize);
   451             assert(dst->longmsg);
   452             if (dst->longmsg == NULL)
   453                 goto enomem;
   454         }
   455         else {
   456             goto pep_error;
   457         }
   458     }
   459     else {
   460         dst->longmsg = strdup("");
   461         assert(dst->longmsg);
   462         if (dst->longmsg == NULL)
   463             goto enomem;
   464     }
   465 
   466     if (src->longmsg_formatted && src->longmsg_formatted[0]) {
   467         ptext = src->longmsg_formatted;
   468         status = encrypt_and_sign(session, keys, ptext, strlen(ptext), &ctext,
   469             &csize);
   470         if (ctext) {
   471             char *_ctext = malloc(csize);
   472             assert(_ctext);
   473             if (_ctext == NULL)
   474                 goto enomem;
   475             memcpy(_ctext, ctext, csize);
   476 
   477             bloblist_t *_a = bloblist_add(dst->attachments, _ctext, csize,
   478                 "application/octet-stream", "PGPexch.htm.pgp");
   479             if (_a == NULL)
   480                 goto enomem;
   481             if (dst->attachments == NULL)
   482                 dst->attachments = _a;
   483         }
   484         else {
   485             goto pep_error;
   486         }
   487     }
   488 
   489     if (src->attachments) {
   490         if (dst->attachments == NULL) {
   491             dst->attachments = new_bloblist(NULL, 0, NULL, NULL);
   492             if (dst->attachments == NULL)
   493                 goto enomem;
   494         }
   495 
   496         bloblist_t *_s = src->attachments;
   497         bloblist_t *_d = dst->attachments;
   498 
   499         for (int n = 0; _s && _s->value; _s = _s->next) {
   500             size_t psize = _s->size;
   501             ptext = _s->value;
   502             status = encrypt_and_sign(session, keys, ptext, psize, &ctext,
   503                 &csize);
   504             if (ctext) {
   505                 char *filename = NULL;
   506 
   507                 if (_s->filename) {
   508                     size_t len = strlen(_s->filename);
   509                     filename = calloc(1, len + 5);
   510                     if (filename == NULL)
   511                         goto enomem;
   512 
   513                     strcpy(filename, _s->filename);
   514                     strcpy(filename + len, ".pgp");
   515                 }
   516                 else {
   517                     filename = calloc(1, 20);
   518                     if (filename == NULL)
   519                         goto enomem;
   520 
   521                     ++n;
   522                     n &= 0xffff;
   523                     snprintf(filename, 20, "Attachment%d.pgp", n);
   524                 }
   525 
   526                 char *_ctext = malloc(csize);
   527                 assert(_ctext);
   528                 if (_ctext == NULL)
   529                     goto enomem;
   530                 memcpy(_ctext, ctext, csize);
   531 
   532                 _d = bloblist_add(_d, _ctext, csize, "application/octet-stream",
   533                     filename);
   534                 if (_d == NULL)
   535                     goto enomem;
   536             }
   537             else {
   538                 goto pep_error;
   539             }
   540         }
   541     }
   542 
   543     return PEP_STATUS_OK;
   544 
   545 enomem:
   546     status = PEP_OUT_OF_MEMORY;
   547 
   548 pep_error:
   549     if (free_ptext)
   550         free(ptext);
   551     return status;
   552 }
   553 
   554 static char * keylist_to_string(const stringlist_t *keylist)
   555 {
   556     if (keylist) {
   557         size_t size = stringlist_length(keylist);
   558 
   559         const stringlist_t *_kl;
   560         for (_kl = keylist; _kl && _kl->value; _kl = _kl->next) {
   561             size += strlen(_kl->value);
   562         }
   563 
   564         char *result = calloc(1, size);
   565         if (result == NULL)
   566             return NULL;
   567 
   568         char *_r = result;
   569         for (_kl = keylist; _kl && _kl->value; _kl = _kl->next) {
   570             _r = stpcpy(_r, _kl->value);
   571             if (_kl->next && _kl->next->value)
   572                 _r = stpcpy(_r, ",");
   573         }
   574 
   575         return result;
   576     }
   577     else {
   578         return NULL;
   579     }
   580 }
   581 
   582 static const char * color_to_string(PEP_color color)
   583 {
   584     switch (color) {
   585     case PEP_rating_cannot_decrypt:
   586         return "cannot_decrypt";
   587     case PEP_rating_have_no_key:
   588         return "have_no_key";
   589     case PEP_rating_unencrypted:
   590         return "unencrypted";
   591     case PEP_rating_unencrypted_for_some:
   592         return "unencrypted_for_some";
   593     case PEP_rating_unreliable:
   594         return "unreliable";
   595     case PEP_rating_reliable:
   596         return "reliable";
   597     case PEP_rating_trusted:
   598         return "trusted";
   599     case PEP_rating_trusted_and_anonymized:
   600         return "trusted_and_anonymized";
   601     case PEP_rating_fully_anonymous:
   602         return "fully_anonymous";
   603     case PEP_rating_mistrust:
   604         return "mistrust";
   605     case PEP_rating_b0rken:
   606         return "b0rken";
   607     case PEP_rating_under_attack:
   608         return "unter_attack";
   609     default:
   610         return "undefined";
   611     }
   612 }
   613 
   614 static void decorate_message(
   615     message *msg,
   616     PEP_color color,
   617     stringlist_t *keylist
   618     )
   619 {
   620     assert(msg);
   621 
   622     add_opt_field(msg, "X-pEp-Version", "1.0");
   623     
   624     if (color != PEP_rating_undefined)
   625         add_opt_field(msg, "X-EncStatus", color_to_string(color));
   626 
   627     if (keylist) {
   628         char *_keylist = keylist_to_string(keylist);
   629         add_opt_field(msg, "X-KeyList", _keylist);
   630         free(_keylist);
   631     }
   632 }
   633 
   634 static PEP_color _rating(PEP_comm_type ct, PEP_color color)
   635 {
   636     if (ct == PEP_ct_unknown)
   637         return PEP_rating_undefined;
   638 
   639     else if (ct == PEP_ct_compromized)
   640         return PEP_rating_under_attack;
   641 
   642     else if (ct == PEP_ct_mistrusted)
   643         return PEP_rating_mistrust;
   644     
   645     if (color == PEP_rating_unencrypted_for_some)
   646         return PEP_rating_unencrypted_for_some;
   647 
   648     if (ct == PEP_ct_no_encryption || ct == PEP_ct_no_encrypted_channel ||
   649             ct == PEP_ct_my_key_not_included) {
   650         if (color > PEP_rating_unencrypted_for_some)
   651             return PEP_rating_unencrypted_for_some;
   652         else
   653             return PEP_rating_unencrypted;
   654     }
   655 
   656     if (color == PEP_rating_unencrypted)
   657         return PEP_rating_unencrypted_for_some;
   658 
   659     if (ct >= PEP_ct_confirmed_enc_anon)
   660         return PEP_rating_trusted_and_anonymized;
   661 
   662     else if (ct >= PEP_ct_strong_encryption)
   663         return PEP_rating_trusted;
   664 
   665     else if (ct >= PEP_ct_strong_but_unconfirmed && ct < PEP_ct_confirmed)
   666         return PEP_rating_reliable;
   667 
   668     else
   669         return PEP_rating_unreliable;
   670 }
   671 
   672 static bool is_encrypted_attachment(const bloblist_t *blob)
   673 {
   674     char *ext;
   675 
   676     assert(blob);
   677 
   678     if (blob->filename == NULL)
   679         return false;
   680 
   681     ext = strrchr(blob->filename, '.');
   682     if (ext == NULL)
   683         return false;
   684 
   685     if (strcmp(blob->mime_type, "application/octet-stream") == 0) {
   686         if (strcmp(ext, ".pgp") == 0 || strcmp(ext, ".gpg") == 0 ||
   687             strcmp(ext, ".asc") == 0)
   688             return true;
   689     }
   690     else if (strcmp(blob->mime_type, "text/plain") == 0) {
   691         if (strcmp(ext, ".asc") == 0)
   692             return true;
   693     }
   694 
   695     return false;
   696 }
   697 
   698 static bool is_encrypted_html_attachment(const bloblist_t *blob)
   699 {
   700     assert(blob);
   701     assert(blob->filename);
   702 
   703     if (strncmp(blob->filename, "PGPexch.htm.", 12) == 0) {
   704         if (strcmp(blob->filename + 11, ".pgp") == 0 ||
   705             strcmp(blob->filename + 11, ".asc") == 0)
   706             return true;
   707     }
   708 
   709     return false;
   710 }
   711 
   712 static char * without_double_ending(const char *filename)
   713 {
   714     char *ext;
   715 
   716     assert(filename);
   717 
   718     ext = strrchr(filename, '.');
   719     if (ext == NULL)
   720         return NULL;
   721 
   722     char *result = strndup(filename, ext - filename);
   723     assert(result);
   724     return result;
   725 }
   726 
   727 static PEP_color decrypt_color(PEP_STATUS status)
   728 {
   729     switch (status) {
   730     case PEP_UNENCRYPTED:
   731     case PEP_VERIFIED:
   732     case PEP_VERIFY_NO_KEY:
   733     case PEP_VERIFIED_AND_TRUSTED:
   734         return PEP_rating_unencrypted;
   735 
   736     case PEP_DECRYPTED:
   737         return PEP_rating_unreliable;
   738 
   739     case PEP_DECRYPTED_AND_VERIFIED:
   740         return PEP_rating_reliable;
   741 
   742     case PEP_DECRYPT_NO_KEY:
   743         return PEP_rating_have_no_key;
   744 
   745     case PEP_DECRYPT_WRONG_FORMAT:
   746     case PEP_CANNOT_DECRYPT_UNKNOWN:
   747         return PEP_rating_cannot_decrypt;
   748 
   749     default:
   750         return PEP_rating_undefined;
   751     }
   752 }
   753 
   754 static PEP_color key_color(PEP_SESSION session, const char *fpr)
   755 {
   756     PEP_comm_type comm_type = PEP_ct_unknown;
   757 
   758     assert(session);
   759     assert(fpr);
   760 
   761     PEP_STATUS status = get_key_rating(session, fpr, &comm_type);
   762     if (status != PEP_STATUS_OK)
   763         return PEP_rating_undefined;
   764 
   765     return _rating(comm_type, PEP_rating_undefined);
   766 }
   767 
   768 static PEP_color keylist_color(PEP_SESSION session, stringlist_t *keylist)
   769 {
   770     PEP_color color = PEP_rating_reliable;
   771 
   772     assert(keylist && keylist->value);
   773     if (keylist == NULL || keylist->value == NULL)
   774         return PEP_rating_undefined;
   775 
   776     stringlist_t *_kl;
   777     for (_kl = keylist; _kl && _kl->value; _kl = _kl->next) {
   778         PEP_comm_type ct;
   779         PEP_STATUS status;
   780 
   781         PEP_color _color = key_color(session, _kl->value);
   782         if (_color <= PEP_rating_mistrust)
   783             return _color;
   784 
   785         if (color == PEP_rating_undefined)
   786             color = _color;
   787 
   788         if (_color >= PEP_rating_reliable) {
   789             status = least_trust(session, _kl->value, &ct);
   790             if (status != PEP_STATUS_OK)
   791                 return PEP_rating_undefined;
   792             if (ct == PEP_ct_unknown)
   793                 color = PEP_rating_unencrypted_for_some;
   794             else
   795                 color = _rating(ct, color);
   796         }
   797         else if (_color == PEP_rating_unencrypted) {
   798             if (color > PEP_rating_unencrypted_for_some)
   799                 color = PEP_rating_unencrypted_for_some;
   800         }
   801     }
   802 
   803     return color;
   804 }
   805 
   806 static PEP_comm_type _get_comm_type(
   807     PEP_SESSION session,
   808     PEP_comm_type max_comm_type,
   809     pEp_identity *ident
   810     )
   811 {
   812     PEP_STATUS status = update_identity(session, ident);
   813 
   814     if (max_comm_type == PEP_ct_compromized)
   815         return PEP_ct_compromized;
   816     
   817     if (max_comm_type == PEP_ct_mistrusted)
   818         return PEP_ct_mistrusted;
   819 
   820     if (status == PEP_STATUS_OK) {
   821         if (ident->comm_type == PEP_ct_compromized)
   822             return PEP_ct_compromized;
   823         else if (ident->comm_type == PEP_ct_mistrusted)
   824             return PEP_ct_mistrusted;
   825         else
   826             return MIN(max_comm_type, ident->comm_type);
   827     }
   828     else {
   829         return PEP_ct_unknown;
   830     }
   831 }
   832 
   833 void import_attached_keys(PEP_SESSION session, const message *msg)
   834 {
   835     assert(session);
   836     assert(msg);
   837 
   838     bloblist_t *bl;
   839     for (bl = msg->attachments; bl && bl->value; bl = bl->next) {
   840         assert(bl && bl->value && bl->size);
   841 
   842         // workaround for Apple Mail bugs
   843         if (is_mime_type(bl, "application/x-apple-msg-attachment")) {
   844             if (is_fileending(bl, ".asc")) {
   845                 if (strlen(bl->filename) == 14 &&
   846                         bl->filename[0] == '0' && bl->filename[1] == 'x')
   847                     import_key(session, bl->value, bl->size);
   848                 else if (strlen(bl->filename) == 12)
   849                     import_key(session, bl->value, bl->size);
   850             }
   851         }
   852         else if (bl->mime_type == NULL ||
   853                     is_mime_type(bl, "application/octet-stream")) {
   854             if (is_fileending(bl, ".pgp") || is_fileending(bl, ".gpg") ||
   855                     is_fileending(bl, ".key") || is_fileending(bl, ".asc"))
   856                 import_key(session, bl->value, bl->size);
   857         }
   858         else if (is_mime_type(bl, "application/pgp-keys")) {
   859             import_key(session, bl->value, bl->size);
   860         }
   861         else if (is_mime_type(bl, "text/plain")) {
   862             if (is_fileending(bl, ".pgp") || is_fileending(bl, ".gpg") ||
   863                     is_fileending(bl, ".key") || is_fileending(bl, ".asc"))
   864                 import_key(session, bl->value, bl->size);
   865         }
   866     }
   867     if(msg->from && msg->from->user_id && msg->from->address)
   868         update_identity(session, msg->from);
   869 }
   870 
   871 void attach_own_key(PEP_SESSION session, message *msg)
   872 {
   873     char *keydata;
   874     size_t size;
   875     bloblist_t *bl;
   876 
   877     assert(session);
   878     assert(msg);
   879 
   880     if (msg->dir == PEP_dir_incoming)
   881         return;
   882 
   883     assert(msg->from && msg->from->fpr);
   884     if (msg->from == NULL || msg->from->fpr == NULL)
   885         return;
   886 
   887     PEP_STATUS status = export_key(session, msg->from->fpr, &keydata, &size);
   888     assert(status == PEP_STATUS_OK);
   889     if (status != PEP_STATUS_OK)
   890         return;
   891     assert(size);
   892 
   893     bl = bloblist_add(msg->attachments, keydata, size, "application/pgp-keys",
   894             "pEpkey.asc");
   895     if (msg->attachments == NULL && bl)
   896         msg->attachments = bl;
   897 }
   898 
   899 PEP_cryptotech determine_encryption_format(message *msg)
   900 {
   901     assert(msg);
   902 
   903     if (is_PGP_message_text(msg->longmsg)) {
   904         msg->enc_format = PEP_enc_pieces;
   905         return PEP_crypt_OpenPGP;
   906     }
   907     else if (msg->attachments && msg->attachments->next &&
   908             is_mime_type(msg->attachments, "application/pgp-encrypted") &&
   909             is_PGP_message_text(msg->attachments->next->value)
   910         ) {
   911         msg->enc_format = PEP_enc_PGP_MIME;
   912         return PEP_crypt_OpenPGP;
   913     }
   914     else {
   915         msg->enc_format = PEP_enc_none;
   916         return PEP_crypt_none;
   917     }
   918 }
   919 
   920 DYNAMIC_API PEP_STATUS encrypt_message(
   921         PEP_SESSION session,
   922         message *src,
   923         stringlist_t * extra,
   924         message **dst,
   925         PEP_enc_format enc_format
   926     )
   927 {
   928     PEP_STATUS status = PEP_STATUS_OK;
   929     message * msg = NULL;
   930     stringlist_t * keys = NULL;
   931 
   932     assert(session);
   933     assert(src);
   934     assert(dst);
   935     assert(enc_format != PEP_enc_none);
   936 
   937     if (!(session && src && dst && enc_format != PEP_enc_none))
   938         return PEP_ILLEGAL_VALUE;
   939 
   940     determine_encryption_format(src);
   941     if (src->enc_format != PEP_enc_none)
   942         return PEP_ILLEGAL_VALUE;
   943 
   944     *dst = NULL;
   945 
   946     status = myself(session, src->from);
   947     if (status != PEP_STATUS_OK)
   948         goto pep_error;
   949 
   950     keys = new_stringlist(src->from->fpr);
   951     if (keys == NULL)
   952         goto enomem;
   953 
   954     stringlist_t *_k = keys;
   955 
   956     if (extra) {
   957         _k = stringlist_append(_k, extra);
   958         if (_k == NULL)
   959             goto enomem;
   960     }
   961 
   962     bool dest_keys_found = true;
   963     PEP_comm_type max_comm_type = PEP_ct_pEp;
   964 
   965     identity_list * _il;
   966     for (_il = src->to; _il && _il->ident; _il = _il->next) {
   967         PEP_STATUS _status = update_identity(session, _il->ident);
   968         if (_status != PEP_STATUS_OK) {
   969             status = _status;
   970             goto pep_error;
   971         }
   972 
   973         if (_il->ident->fpr && _il->ident->fpr[0]) {
   974             _k = stringlist_add(_k, _il->ident->fpr);
   975             if (_k == NULL)
   976                 goto enomem;
   977             max_comm_type = _get_comm_type(session, max_comm_type,
   978                                            _il->ident);
   979         }
   980         else {
   981             dest_keys_found = false;
   982             status = PEP_KEY_NOT_FOUND;
   983         }
   984     }
   985 
   986     for (_il = src->cc; _il && _il->ident; _il = _il->next) {
   987         PEP_STATUS _status = update_identity(session, _il->ident);
   988         if (_status != PEP_STATUS_OK)
   989         {
   990             status = _status;
   991             goto pep_error;
   992         }
   993 
   994         if (_il->ident->fpr && _il->ident->fpr[0]) {
   995             _k = stringlist_add(_k, _il->ident->fpr);
   996             if (_k == NULL)
   997                 goto enomem;
   998             max_comm_type = _get_comm_type(session, max_comm_type,
   999                                            _il->ident);
  1000         }
  1001         else {
  1002             dest_keys_found = false;
  1003             status = PEP_KEY_NOT_FOUND;
  1004         }
  1005     }
  1006     
  1007     if (!dest_keys_found ||
  1008         stringlist_length(keys) == 0 ||
  1009         _rating(max_comm_type,
  1010                 PEP_rating_undefined) < PEP_rating_reliable)
  1011     {
  1012         free_stringlist(keys);
  1013         if (!session->passive_mode)
  1014             attach_own_key(session, src);
  1015         return PEP_UNENCRYPTED;
  1016     }
  1017     else {
  1018         msg = clone_to_empty_message(src);
  1019         if (msg == NULL)
  1020             goto enomem;
  1021 
  1022         attach_own_key(session, src);
  1023 
  1024         switch (enc_format) {
  1025         case PEP_enc_PGP_MIME:
  1026         case PEP_enc_PEP: // BUG: should be implemented extra
  1027             status = encrypt_PGP_MIME(session, src, keys, msg);
  1028             break;
  1029 
  1030         case PEP_enc_pieces:
  1031             status = encrypt_PGP_in_pieces(session, src, keys, msg);
  1032             break;
  1033 
  1034         /* case PEP_enc_PEP:
  1035             // TODO: implement
  1036             NOT_IMPLEMENTED */
  1037 
  1038         default:
  1039             assert(0);
  1040             status = PEP_ILLEGAL_VALUE;
  1041             goto pep_error;
  1042         }
  1043         
  1044         if (status == PEP_OUT_OF_MEMORY)
  1045             goto enomem;
  1046         
  1047         if (status != PEP_STATUS_OK)
  1048             goto pep_error;
  1049     }
  1050 
  1051     free_stringlist(keys);
  1052 
  1053     if (msg && msg->shortmsg == NULL) {
  1054         msg->shortmsg = strdup("pEp");
  1055         assert(msg->shortmsg);
  1056     }
  1057 
  1058     if (msg)
  1059         decorate_message(msg, PEP_rating_undefined, NULL);
  1060 
  1061     *dst = msg;
  1062     return status;
  1063 
  1064 enomem:
  1065     status = PEP_OUT_OF_MEMORY;
  1066 
  1067 pep_error:
  1068     free_stringlist(keys);
  1069     free_message(msg);
  1070 
  1071     return status;
  1072 }
  1073 
  1074 DYNAMIC_API PEP_STATUS decrypt_message(
  1075         PEP_SESSION session,
  1076         message *src,
  1077         message **dst,
  1078         stringlist_t **keylist,
  1079         PEP_color *color
  1080     )
  1081 {
  1082     PEP_STATUS status = PEP_STATUS_OK;
  1083     PEP_STATUS decrypt_status = PEP_CANNOT_DECRYPT_UNKNOWN;
  1084     message *msg = NULL;
  1085     char *ctext;
  1086     size_t csize;
  1087     char *ptext = NULL;
  1088     size_t psize;
  1089     stringlist_t *_keylist = NULL;
  1090 
  1091     assert(session);
  1092     assert(src);
  1093     assert(dst);
  1094     assert(keylist);
  1095     assert(color);
  1096 
  1097     if (!(session && src && dst && keylist && color))
  1098         return PEP_ILLEGAL_VALUE;
  1099 
  1100     import_attached_keys(session, src);
  1101     PEP_cryptotech crypto = determine_encryption_format(src);
  1102 
  1103     *dst = NULL;
  1104     *keylist = NULL;
  1105     *color = PEP_rating_undefined;
  1106  
  1107     switch (src->enc_format) {
  1108         case PEP_enc_none:
  1109             *color = PEP_rating_unencrypted;
  1110             return PEP_UNENCRYPTED;
  1111 
  1112         case PEP_enc_PGP_MIME:
  1113             ctext = src->attachments->next->value;
  1114             csize = src->attachments->next->size;
  1115             break;
  1116 
  1117         case PEP_enc_pieces:
  1118             ctext = src->longmsg;
  1119             csize = strlen(ctext);
  1120             break;
  1121 
  1122         default:
  1123             NOT_IMPLEMENTED
  1124     }
  1125     status = cryptotech[crypto].decrypt_and_verify(session, ctext,
  1126                                                    csize, &ptext, &psize, &_keylist);
  1127     if (status > PEP_CANNOT_DECRYPT_UNKNOWN)
  1128         goto pep_error;
  1129 
  1130     decrypt_status = status;
  1131 
  1132     if (ptext) {
  1133         switch (src->enc_format) {
  1134             case PEP_enc_PGP_MIME:
  1135                 status = mime_decode_message(ptext, psize, &msg);
  1136                 if (status != PEP_STATUS_OK)
  1137                     goto pep_error;
  1138                 break;
  1139 
  1140             case PEP_enc_pieces:
  1141                 msg = clone_to_empty_message(src);
  1142                 if (msg == NULL)
  1143                     goto enomem;
  1144 
  1145                 msg->longmsg = strdup(ptext);
  1146                 assert(msg->longmsg);
  1147                 if (msg->longmsg == NULL)
  1148                     goto enomem;
  1149 
  1150                 bloblist_t *_m = msg->attachments;
  1151                 if (_m == NULL && src->attachments && src->attachments->value) {
  1152                     msg->attachments = new_bloblist(NULL, 0, NULL, NULL);
  1153                     _m = msg->attachments;
  1154                 }
  1155 
  1156                 bloblist_t *_s;
  1157                 for (_s = src->attachments; _s && _s->value; _s = _s->next) {
  1158                     if (is_encrypted_attachment(_s)) {
  1159                         stringlist_t *_keylist = NULL;
  1160                         char *attctext;
  1161                         size_t attcsize;
  1162 
  1163                         attctext = _s->value;
  1164                         attcsize = _s->size;
  1165 
  1166                         status = decrypt_and_verify(session, attctext, attcsize,
  1167                                 &ptext, &psize, &_keylist);
  1168                         free_stringlist(_keylist);
  1169 
  1170                         if (ptext) {
  1171                             if (is_encrypted_html_attachment(_s)) {
  1172                                 msg->longmsg_formatted = strdup(ptext);
  1173                                 assert(msg->longmsg_formatted);
  1174                                 if (msg->longmsg_formatted == NULL)
  1175                                     goto pep_error;
  1176                             }
  1177                             else {
  1178                                 char * mime_type = "application/octet-stream";
  1179                                 char * filename =
  1180                                     without_double_ending(_s->filename);
  1181                                 if (filename == NULL)
  1182                                     goto enomem;
  1183 
  1184                                 char *_ptext = malloc(psize);
  1185                                 assert(_ptext);
  1186                                 if (_ptext == NULL)
  1187                                     goto enomem;
  1188                                 memcpy(_ptext, ptext, psize);
  1189 
  1190                                 _m = bloblist_add(_m, _ptext, psize, mime_type,
  1191                                     filename);
  1192                                 if (_m == NULL)
  1193                                     goto enomem;
  1194 
  1195                                 if (msg->attachments == NULL)
  1196                                     msg->attachments = _m;
  1197                             }
  1198                         }
  1199                         else {
  1200                             char *copy = malloc(_s->size);
  1201                             assert(copy);
  1202                             if (copy == NULL)
  1203                                 goto enomem;
  1204                             memcpy(copy, _s->value, _s->size);
  1205                             _m = bloblist_add(_m, copy, _s->size, _s->mime_type, _s->filename);
  1206                             if (_m == NULL)
  1207                                 goto enomem;
  1208                         }
  1209                     }
  1210                     else {
  1211                         char *copy = malloc(_s->size);
  1212                         assert(copy);
  1213                         if (copy == NULL)
  1214                             goto enomem;
  1215                         memcpy(copy, _s->value, _s->size);
  1216                         _m = bloblist_add(_m, copy, _s->size, _s->mime_type, _s->filename);
  1217                         if (_m == NULL)
  1218                             goto enomem;
  1219                     }
  1220                 }
  1221 
  1222                 break;
  1223 
  1224             default:
  1225                 // BUG: must implement more
  1226                 NOT_IMPLEMENTED
  1227         }
  1228         
  1229         switch (src->enc_format) {
  1230             case PEP_enc_PGP_MIME:
  1231             case PEP_enc_pieces:
  1232                 status = copy_fields(msg, src);
  1233                 if (status != PEP_STATUS_OK)
  1234                     goto pep_error;
  1235 
  1236                 if (src->shortmsg == NULL || strcmp(src->shortmsg, "pEp") == 0)
  1237                 {
  1238                     char * shortmsg;
  1239                     char * longmsg;
  1240 
  1241                     int r = seperate_short_and_long(msg->longmsg, &shortmsg,
  1242                             &longmsg);
  1243                     if (r == -1)
  1244                         goto enomem;
  1245 
  1246                     free(msg->shortmsg);
  1247                     free(msg->longmsg);
  1248 
  1249                     msg->shortmsg = shortmsg;
  1250                     msg->longmsg = longmsg;
  1251                 }
  1252                 else {
  1253                     msg->shortmsg = strdup(src->shortmsg);
  1254                     assert(msg->shortmsg);
  1255                     if (msg->shortmsg == NULL)
  1256                         goto enomem;
  1257                 }
  1258                 break;
  1259 
  1260             default:
  1261                 // BUG: must implement more
  1262                 NOT_IMPLEMENTED
  1263         }
  1264         
  1265         import_attached_keys(session, msg);
  1266         
  1267         if(decrypt_status == PEP_DECRYPTED){
  1268             
  1269             // In case message did decrypt, but no valid signature could be found
  1270             // then retry decrypt+verify after importing key.
  1271             // TODO optimize if import_attached_keys didn't import any key
  1272             
  1273             char *re_ptext = NULL;
  1274             size_t re_psize;
  1275             
  1276             free_stringlist(_keylist);
  1277             _keylist = NULL;
  1278 
  1279             status = cryptotech[crypto].decrypt_and_verify(session, ctext,
  1280                 csize, &re_ptext, &re_psize, &_keylist);
  1281             
  1282             if(re_ptext)
  1283                 free(re_ptext);
  1284             
  1285             if (status > PEP_CANNOT_DECRYPT_UNKNOWN)
  1286                 goto pep_error;
  1287             
  1288             decrypt_status = status;
  1289         }
  1290         
  1291         *color = decrypt_color(decrypt_status);
  1292         
  1293         if (*color > PEP_rating_mistrust) {
  1294             PEP_color kl_color = PEP_rating_undefined;
  1295             
  1296             if (_keylist)
  1297                 kl_color = keylist_color(session, _keylist);
  1298             
  1299             if (kl_color <= PEP_rating_mistrust) {
  1300                 *color = kl_color;
  1301             }
  1302             else if (*color >= PEP_rating_reliable &&
  1303                      kl_color < PEP_rating_reliable) {
  1304                 *color = PEP_rating_unreliable;
  1305             }
  1306             else if (*color >= PEP_rating_reliable &&
  1307                      kl_color >= PEP_rating_reliable) {
  1308                 if (!(src->from && src->from->user_id && src->from->user_id[0])) {
  1309                     *color = PEP_rating_unreliable;
  1310                 }
  1311                 else {
  1312                     char *fpr = _keylist->value;
  1313                     pEp_identity *_from = new_identity(src->from->address, fpr,
  1314                                                        src->from->user_id, src->from->username);
  1315                     if (_from == NULL)
  1316                         goto enomem;
  1317                     status = update_identity(session, _from);
  1318                     if (_from->comm_type != PEP_ct_unknown)
  1319                         *color = _rating(_from->comm_type, PEP_rating_undefined);
  1320                     free_identity(_from);
  1321                     if (status != PEP_STATUS_OK)
  1322                         goto pep_error;
  1323                 }
  1324             }
  1325         }
  1326     }
  1327 
  1328     if (msg)
  1329         decorate_message(msg, *color, _keylist);
  1330 
  1331     *dst = msg;
  1332     *keylist = _keylist;
  1333 
  1334     return PEP_STATUS_OK;
  1335 
  1336 enomem:
  1337     status = PEP_OUT_OF_MEMORY;
  1338 
  1339 pep_error:
  1340     free_message(msg);
  1341     free_stringlist(_keylist);
  1342 
  1343     return status;
  1344 }
  1345 
  1346 DYNAMIC_API PEP_STATUS outgoing_message_color(
  1347         PEP_SESSION session,
  1348         message *msg,
  1349         PEP_color *color
  1350     )
  1351 {
  1352     PEP_STATUS status = PEP_STATUS_OK;
  1353     PEP_comm_type max_comm_type = PEP_ct_pEp;
  1354     bool comm_type_determined = false;
  1355     identity_list * il;
  1356 
  1357     assert(session);
  1358     assert(msg);
  1359     assert(msg->from);
  1360     assert(msg->dir == PEP_dir_outgoing);
  1361     assert(color);
  1362 
  1363     if (!(session && msg && color))
  1364         return PEP_ILLEGAL_VALUE;
  1365 
  1366     if (msg->from == NULL || msg->dir != PEP_dir_outgoing)
  1367         return PEP_ILLEGAL_VALUE;
  1368 
  1369     *color = PEP_rating_undefined;
  1370 
  1371     status = myself(session, msg->from);
  1372     if (status != PEP_STATUS_OK)
  1373         return status;
  1374 
  1375     for (il = msg->to; il != NULL; il = il->next) {
  1376         if (il->ident) {
  1377             update_identity(session, il->ident);
  1378             max_comm_type = _get_comm_type(session, max_comm_type,
  1379                     il->ident);
  1380             comm_type_determined = true;
  1381         }
  1382     }
  1383 
  1384     for (il = msg->cc; il != NULL; il = il->next) {
  1385         if (il->ident) {
  1386             update_identity(session, il->ident);
  1387             max_comm_type = _get_comm_type(session, max_comm_type,
  1388                     il->ident);
  1389             comm_type_determined = true;
  1390         }
  1391     }
  1392 
  1393     if (comm_type_determined == false)
  1394         *color = PEP_rating_undefined;
  1395     else
  1396         *color = MAX(_rating(max_comm_type, PEP_rating_undefined),
  1397                 PEP_rating_unencrypted);
  1398 
  1399     return PEP_STATUS_OK;
  1400 }
  1401 
  1402 DYNAMIC_API PEP_STATUS identity_color(
  1403         PEP_SESSION session,
  1404         pEp_identity *ident,
  1405         PEP_color *color
  1406     )
  1407 {
  1408     PEP_STATUS status = PEP_STATUS_OK;
  1409 
  1410     assert(session);
  1411     assert(ident);
  1412     assert(color);
  1413 
  1414     if (!(session && ident && color))
  1415         return PEP_ILLEGAL_VALUE;
  1416 
  1417     if (ident->me)
  1418         status = myself(session, ident);
  1419     else
  1420         status = update_identity(session, ident);
  1421 
  1422     if (status == PEP_STATUS_OK)
  1423         *color = _rating(ident->comm_type, PEP_rating_undefined);
  1424 
  1425     return status;
  1426 }
  1427 
  1428 DYNAMIC_API PEP_STATUS get_binary_path(PEP_cryptotech tech, const char **path)
  1429 {
  1430     PEP_STATUS status = PEP_STATUS_OK;
  1431 
  1432     assert(path);
  1433     if (path == NULL)
  1434         return PEP_ILLEGAL_VALUE;
  1435 
  1436     if (cryptotech[tech].binary_path == NULL)
  1437         *path = NULL;
  1438     else
  1439         status = cryptotech[tech].binary_path(path);
  1440 
  1441     return status;
  1442 }
  1443