X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fsrc%2Fpdkim%2Fpdkim.c;h=61e3161d43eeb31eec9c885934e2578c18e1cac6;hb=6c140c0137225dff8b08d62df9c4ecc1093c6cbc;hp=4309675e6d86f48bc55b297cd5388a2895ac26af;hpb=bd8fbe3606d80e5a3fc02fe71b521146c6938448;p=user%2Fhenk%2Fcode%2Fexim.git diff --git a/src/src/pdkim/pdkim.c b/src/src/pdkim/pdkim.c index 4309675e6..61e3161d4 100644 --- a/src/src/pdkim/pdkim.c +++ b/src/src/pdkim/pdkim.c @@ -2,7 +2,7 @@ * PDKIM - a RFC4871 (DKIM) implementation * * Copyright (C) 2009 - 2016 Tom Kistner - * Copyright (C) 2016 Jeremy Harris + * Copyright (C) 2016 - 2017 Jeremy Harris * * http://duncanthrax.net/pdkim/ * @@ -142,19 +142,19 @@ switch(ext_status) } } -const char * +const uschar * pdkim_errstr(int status) { switch(status) { - case PDKIM_OK: return "OK"; - case PDKIM_FAIL: return "FAIL"; - case PDKIM_ERR_RSA_PRIVKEY: return "RSA_PRIVKEY"; - case PDKIM_ERR_RSA_SIGNING: return "RSA SIGNING"; - case PDKIM_ERR_LONG_LINE: return "RSA_LONG_LINE"; - case PDKIM_ERR_BUFFER_TOO_SMALL: return "BUFFER_TOO_SMALL"; - case PDKIM_SIGN_PRIVKEY_WRAP: return "PRIVKEY_WRAP"; - case PDKIM_SIGN_PRIVKEY_B64D: return "PRIVKEY_B64D"; + case PDKIM_OK: return US"OK"; + case PDKIM_FAIL: return US"FAIL"; + case PDKIM_ERR_RSA_PRIVKEY: return US"RSA_PRIVKEY"; + case PDKIM_ERR_RSA_SIGNING: return US"RSA SIGNING"; + case PDKIM_ERR_LONG_LINE: return US"RSA_LONG_LINE"; + case PDKIM_ERR_BUFFER_TOO_SMALL: return US"BUFFER_TOO_SMALL"; + case PDKIM_SIGN_PRIVKEY_WRAP: return US"PRIVKEY_WRAP"; + case PDKIM_SIGN_PRIVKEY_B64D: return US"PRIVKEY_B64D"; default: return "(unknown)"; } } @@ -192,7 +192,8 @@ static void pdkim_hexprint(const uschar *data, int len) { int i; -for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]); +if (data) for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]); +else debug_printf(""); debug_printf("\n"); } @@ -415,7 +416,7 @@ return b64encode(b->data, b->len); static pdkim_signature * pdkim_parse_sig_header(pdkim_ctx *ctx, uschar * raw_hdr) { -pdkim_signature *sig ; +pdkim_signature * sig; uschar *p, *q; uschar * cur_tag = NULL; int ts = 0, tl = 0; uschar * cur_val = NULL; int vs = 0, vl = 0; @@ -493,10 +494,8 @@ for (p = raw_hdr; ; p++) switch (*cur_tag) { case 'b': - if (cur_tag[1] == 'h') - pdkim_decode_base64(cur_val, &sig->bodyhash); - else - pdkim_decode_base64(cur_val, &sig->sigdata); + pdkim_decode_base64(cur_val, + cur_tag[1] == 'h' ? &sig->bodyhash : &sig->sighash); break; case 'v': /* We only support version 1, and that is currently the @@ -578,12 +577,17 @@ DEBUG(D_acl) "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val)); debug_printf( - "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sigdata.len*8); + "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sighash.len*8); debug_printf( "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); } -exim_sha_init(&sig->body_hash, sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); +if (!exim_sha_init(&sig->body_hash_ctx, + sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256)) + { + DEBUG(D_acl) debug_printf("PDKIM: hash init internal error\n"); + return NULL; + } return sig; } @@ -697,15 +701,14 @@ return NULL; /* -------------------------------------------------------------------------- */ static int -pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len) +pdkim_update_bodyhash(pdkim_ctx * ctx, const char * data, int len) { -pdkim_signature *sig = ctx->sig; -/* Cache relaxed version of data */ -uschar *relaxed_data = NULL; -int relaxed_len = 0; +pdkim_signature * sig; +uschar * relaxed_data = NULL; /* Cache relaxed version of data */ +int relaxed_len = 0; /* Traverse all signatures, updating their hashes. */ -while (sig) +for (sig = ctx->sig; sig; sig = sig->next) { /* Defaults to simple canon (no further treatment necessary) */ const uschar *canon_data = CUS data; @@ -761,12 +764,10 @@ while (sig) if (canon_len > 0) { - exim_sha_update(&sig->body_hash, CUS canon_data, canon_len); + exim_sha_update(&sig->body_hash_ctx, CUS canon_data, canon_len); sig->signed_body_bytes += canon_len; DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len); } - - sig = sig->next; } if (relaxed_data) store_free(relaxed_data); @@ -786,7 +787,7 @@ for (sig = ctx->sig; sig; sig = sig->next) { /* Finish hashes */ blob bh; - exim_sha_finish(&sig->body_hash, &bh); + exim_sha_finish(&sig->body_hash_ctx, &bh); DEBUG(D_acl) { @@ -807,11 +808,11 @@ for (sig = ctx->sig; sig; sig = sig->next) sig->bodylength = -1; } - /* VERIFICATION --------------------------------------------------------- */ else - { - /* Compare bodyhash */ - if (memcmp(bh.data, sig->bodyhash.data, bh.len) == 0) + /* VERIFICATION --------------------------------------------------------- */ + /* Be careful that the header sig included a bodyash */ + + if (sig->bodyhash.data && memcmp(bh.data, sig->bodyhash.data, bh.len) == 0) { DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain); } @@ -820,14 +821,12 @@ for (sig = ctx->sig; sig; sig = sig->next) DEBUG(D_acl) { debug_printf("PDKIM [%s] Body hash signature from headers: ", sig->domain); - pdkim_hexprint(sig->bodyhash.data, - exim_sha_hashlen(&sig->body_hash)); + pdkim_hexprint(sig->bodyhash.data, sig->bodyhash.len); debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain); } sig->verify_status = PDKIM_VERIFY_FAIL; sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY; } - } } } @@ -932,73 +931,65 @@ return PDKIM_OK; #define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:" static int -pdkim_header_complete(pdkim_ctx *ctx) +pdkim_header_complete(pdkim_ctx * ctx) { +pdkim_signature * sig, * last_sig; + /* Special case: The last header can have an extra \r appended */ if ( (ctx->cur_header_len > 1) && (ctx->cur_header[(ctx->cur_header_len)-1] == '\r') ) --ctx->cur_header_len; ctx->cur_header[ctx->cur_header_len] = '\0'; -ctx->num_headers++; -if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; +if (++ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; /* SIGNING -------------------------------------------------------------- */ if (ctx->flags & PDKIM_MODE_SIGN) - { - pdkim_signature *sig; - for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */ /* Add header to the signed headers list (in reverse order) */ sig->headers = pdkim_prepend_stringlist(sig->headers, ctx->cur_header); - } /* VERIFICATION ----------------------------------------------------------- */ /* DKIM-Signature: headers are added to the verification list */ else { +#ifdef notdef DEBUG(D_acl) { debug_printf("PDKIM >> raw hdr: "); - pdkim_quoteprint(CUS ctx->cur_header, Ustrlen(ctx->cur_header)); + pdkim_quoteprint(CUS ctx->cur_header, ctx->cur_header_len); } +#endif if (strncasecmp(CCS ctx->cur_header, DKIM_SIGNATURE_HEADERNAME, Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0) { - pdkim_signature *new_sig; + /* Create and chain new signature block. We could error-check for all + required tags here, but prefer to create the internal sig and expicitly + fail verification of it later. */ - /* Create and chain new signature block */ DEBUG(D_acl) debug_printf( "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); - if ((new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header))) + sig = pdkim_parse_sig_header(ctx, ctx->cur_header); + + if (!(last_sig = ctx->sig)) + ctx->sig = sig; + else { - pdkim_signature *last_sig = ctx->sig; - if (!last_sig) - ctx->sig = new_sig; - else - { - while (last_sig->next) last_sig = last_sig->next; - last_sig->next = new_sig; - } + while (last_sig->next) last_sig = last_sig->next; + last_sig->next = sig; } - else - DEBUG(D_acl) debug_printf( - "Error while parsing signature header\n" - "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); } - /* every other header is stored for signature verification */ - else - ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header); + /* all headers are stored for signature verification */ + ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header); } BAIL: -*ctx->cur_header = '\0'; -ctx->cur_header_len = 0; /* leave buffer for reuse */ +ctx->cur_header[ctx->cur_header_len = 0] = '\0'; /* leave buffer for reuse */ return PDKIM_OK; } @@ -1010,7 +1001,7 @@ return PDKIM_OK; DLLEXPORT int pdkim_feed(pdkim_ctx *ctx, char *data, int len) { -int p; +int p, rc; /* Alternate EOD signal, used in non-dotstuffing mode */ if (!data) @@ -1035,7 +1026,6 @@ else for (p = 0; pflags |= PDKIM_SEEN_CR; else if (c == '\n') { - int rc; ctx->flags &= ~PDKIM_SEEN_CR; if ((rc = pdkim_bodyline_complete(ctx)) != PDKIM_OK) return rc; @@ -1055,26 +1045,24 @@ else for (p = 0; pcur_header = string_catn(ctx->cur_header, &ctx->cur_header_size, &ctx->cur_header_len, CUS "\r", 1); - if (ctx->flags & PDKIM_SEEN_LF) + if (ctx->flags & PDKIM_SEEN_LF) /* Seen last header line */ { - int rc = pdkim_header_complete(ctx); /* Seen last header line */ - if (rc != PDKIM_OK) return rc; + if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK) + return rc; - ctx->flags = ctx->flags & ~(PDKIM_SEEN_LF|PDKIM_SEEN_CR) | PDKIM_PAST_HDRS; + ctx->flags = (ctx->flags & ~(PDKIM_SEEN_LF|PDKIM_SEEN_CR)) | PDKIM_PAST_HDRS; DEBUG(D_acl) debug_printf( - "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>\n"); + "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); continue; } else - ctx->flags = ctx->flags & ~PDKIM_SEEN_CR | PDKIM_SEEN_LF; + ctx->flags = (ctx->flags & ~PDKIM_SEEN_CR) | PDKIM_SEEN_LF; } else if (ctx->flags & PDKIM_SEEN_LF) { - if (!(c == '\t' || c == ' ')) - { - int rc = pdkim_header_complete(ctx); /* End of header */ - if (rc != PDKIM_OK) return rc; - } + if (!(c == '\t' || c == ' ')) /* End of header */ + if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK) + return rc; ctx->flags &= ~PDKIM_SEEN_LF; } @@ -1309,7 +1297,7 @@ if (sig->bodylength >= 0) } /* Preliminary or final version? */ -base64_b = final ? pdkim_encode_base64(&sig->sigdata) : US""; +base64_b = final ? pdkim_encode_base64(&sig->sighash) : US""; hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=", base64_b); /* add trailing semicolon: I'm not sure if this is actually needed */ @@ -1323,11 +1311,11 @@ return hdr; /* -------------------------------------------------------------------------- */ static pdkim_pubkey * -pdkim_key_from_dns(pdkim_ctx * ctx, pdkim_signature * sig, ev_ctx * vctx) +pdkim_key_from_dns(pdkim_ctx * ctx, pdkim_signature * sig, ev_ctx * vctx, + const uschar ** errstr) { uschar * dns_txt_name, * dns_txt_reply; pdkim_pubkey * p; -const uschar * errstr; /* Fetch public key for signing domain, from DNS */ @@ -1376,9 +1364,9 @@ DEBUG(D_acl) debug_printf( "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); /* Import public key */ -if ((errstr = exim_rsa_verify_init(&p->key, vctx))) +if ((*errstr = exim_rsa_verify_init(&p->key, vctx))) { - DEBUG(D_acl) debug_printf("verify_init: %s\n", errstr); + DEBUG(D_acl) debug_printf("verify_init: %s\n", *errstr); sig->verify_status = PDKIM_VERIFY_INVALID; sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT; return NULL; @@ -1391,7 +1379,8 @@ return p; /* -------------------------------------------------------------------------- */ DLLEXPORT int -pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures) +pdkim_feed_finish(pdkim_ctx * ctx, pdkim_signature ** return_signatures, + const uschar ** err) { pdkim_signature *sig = ctx->sig; @@ -1423,10 +1412,14 @@ while (sig) hdata.data = NULL; hdata.len = 0; - exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256); + if (!exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256)) + { + DEBUG(D_acl) debug_printf("PDKIM: hask setup internal error\n"); + break; + } DEBUG(D_acl) debug_printf( - "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>>>\n"); + "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>\n"); /* SIGNING ---------------------------------------------------------------- */ /* When signing, walk through our header list and add them to the hash. As we @@ -1568,12 +1561,11 @@ while (sig) if (ctx->flags & PDKIM_MODE_SIGN) { es_ctx sctx; - const uschar * errstr; /* Import private key */ - if ((errstr = exim_rsa_signing_init(US sig->rsa_privkey, &sctx))) + if ((*err = exim_rsa_signing_init(US sig->rsa_privkey, &sctx))) { - DEBUG(D_acl) debug_printf("signing_init: %s\n", errstr); + DEBUG(D_acl) debug_printf("signing_init: %s\n", *err); return PDKIM_ERR_RSA_PRIVKEY; } @@ -1585,16 +1577,16 @@ while (sig) hdata = hhash; #endif - if ((errstr = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sigdata))) + if ((*err = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sighash))) { - DEBUG(D_acl) debug_printf("signing: %s\n", errstr); + DEBUG(D_acl) debug_printf("signing: %s\n", *err); return PDKIM_ERR_RSA_SIGNING; } DEBUG(D_acl) { debug_printf( "PDKIM [%s] b computed: ", sig->domain); - pdkim_hexprint(sig->sigdata.data, sig->sigdata.len); + pdkim_hexprint(sig->sighash.data, sig->sighash.len); } sig->signature_header = pdkim_create_header(sig, TRUE); @@ -1604,15 +1596,13 @@ while (sig) else { ev_ctx vctx; - const uschar * errstr; - pdkim_pubkey * p; /* Make sure we have all required signature tags */ if (!( sig->domain && *sig->domain && sig->selector && *sig->selector && sig->headernames && *sig->headernames && sig->bodyhash.data - && sig->sigdata.data + && sig->sighash.data && sig->algo > -1 && sig->version ) ) @@ -1638,13 +1628,13 @@ while (sig) goto NEXT_VERIFY; } - if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx))) + if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err))) goto NEXT_VERIFY; /* Check the signature */ - if ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sigdata))) + if ((*err = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sighash))) { - DEBUG(D_acl) debug_printf("headers verify: %s\n", errstr); + DEBUG(D_acl) debug_printf("headers verify: %s\n", *err); sig->verify_status = PDKIM_VERIFY_FAIL; sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE; goto NEXT_VERIFY; @@ -1702,7 +1692,8 @@ return ctx; DLLEXPORT pdkim_ctx * pdkim_init_sign(char * domain, char * selector, char * rsa_privkey, int algo, - BOOL dot_stuffed, int(*dns_txt_callback)(char *, char *)) + BOOL dot_stuffed, int(*dns_txt_callback)(char *, char *), + const uschar ** errstr) { pdkim_ctx * ctx; pdkim_signature * sig; @@ -1729,19 +1720,23 @@ sig->selector = string_copy(US selector); sig->rsa_privkey = string_copy(US rsa_privkey); sig->algo = algo; -exim_sha_init(&sig->body_hash, algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); +if (!exim_sha_init(&sig->body_hash_ctx, + algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256)) + { + DEBUG(D_acl) debug_printf("PDKIM: hash setup internal error\n"); + return NULL; + } DEBUG(D_acl) { pdkim_signature s = *sig; ev_ctx vctx; - debug_printf("PDKIM (checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); - if (!pdkim_key_from_dns(ctx, &s, &vctx)) + debug_printf("PDKIM (checking verify key)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); + if (!pdkim_key_from_dns(ctx, &s, &vctx, errstr)) debug_printf("WARNING: bad dkim key in dns\n"); - debug_printf("PDKIM (finished checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); + debug_printf("PDKIM (finished checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); } - return ctx; }