X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/9e70917d0aa5e51f584b2af69ce80df458ac5c79..b2bcdd35f0923e96b717d035e9d991b50a38eb50:/src/src/dkim.c diff --git a/src/src/dkim.c b/src/src/dkim.c index ea2007225..5e97c1b79 100644 --- a/src/src/dkim.c +++ b/src/src/dkim.c @@ -12,7 +12,20 @@ #ifndef DISABLE_DKIM -#include "pdkim/pdkim.h" +# include "pdkim/pdkim.h" + +# ifdef MACRO_PREDEF +# include "macro_predef.h" + +void +params_dkim(void) +{ +builtin_macro_create_var(US"_DKIM_SIGN_HEADERS", US PDKIM_DEFAULT_SIGN_HEADERS); +} +# else /*!MACRO_PREDEF*/ + + + int dkim_verify_oldpool; pdkim_ctx *dkim_verify_ctx = NULL; @@ -121,189 +134,255 @@ store_pool = dkim_verify_oldpool; } -void -dkim_exim_verify_finish(void) +/* Log the result for the given signature */ +static void +dkim_exim_verify_log_sig(pdkim_signature * sig) { -pdkim_signature * sig = NULL; -int dkim_signers_size = 0, dkim_signers_ptr = 0, rc; -const uschar * errstr; - -store_pool = POOL_PERM; - -/* Delete eventual previous signature chain */ - -dkim_signers = NULL; -dkim_signatures = NULL; - -if (dkim_collect_error) - { - log_write(0, LOG_MAIN, - "DKIM: Error during validation, disabling signature verification: %.100s", - dkim_collect_error); - dkim_disable_verify = TRUE; - goto out; - } - -dkim_collect_input = FALSE; - -/* Finish DKIM operation and fetch link to signatures chain */ - -rc = pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures, &errstr); -if (rc != PDKIM_OK) - { - log_write(0, LOG_MAIN, "DKIM: validation error: %.100s%s%s", pdkim_errstr(rc), - errstr ? ": " : "", errstr ? errstr : US""); - goto out; - } - -for (sig = dkim_signatures; sig; sig = sig->next) - { - int size = 0, ptr = 0; - uschar * logmsg = NULL, * s; - - /* Log a line for each signature */ - - if (!(s = sig->domain)) s = US""; - logmsg = string_append(logmsg, &size, &ptr, 2, "d=", s); - if (!(s = sig->selector)) s = US""; - logmsg = string_append(logmsg, &size, &ptr, 2, " s=", s); - logmsg = string_append(logmsg, &size, &ptr, 7, - " c=", sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", - "/", sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", - " a=", dkim_sig_to_a_tag(sig), - string_sprintf(" b=%d", - (int)sig->sighash.len > -1 ? sig->sighash.len * 8 : 0)); - if ((s= sig->identity)) logmsg = string_append(logmsg, &size, &ptr, 2, " i=", s); - if (sig->created > 0) logmsg = string_append(logmsg, &size, &ptr, 1, - string_sprintf(" t=%lu", sig->created)); - if (sig->expires > 0) logmsg = string_append(logmsg, &size, &ptr, 1, - string_sprintf(" x=%lu", sig->expires)); - if (sig->bodylength > -1) logmsg = string_append(logmsg, &size, &ptr, 1, - string_sprintf(" l=%lu", sig->bodylength)); - +gstring * logmsg; +uschar * s; + +if (!sig) return; + +logmsg = string_catn(NULL, US"DKIM: ", 6); +if (!(s = sig->domain)) s = US""; +logmsg = string_append(logmsg, 2, "d=", s); +if (!(s = sig->selector)) s = US""; +logmsg = string_append(logmsg, 2, " s=", s); +logmsg = string_append(logmsg, 7, +" c=", sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", +"/", sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", +" a=", dkim_sig_to_a_tag(sig), +string_sprintf(" b=" SIZE_T_FMT, + (int)sig->sighash.len > -1 ? sig->sighash.len * 8 : 0)); +if ((s= sig->identity)) logmsg = string_append(logmsg, 2, " i=", s); +if (sig->created > 0) logmsg = string_cat(logmsg, + string_sprintf(" t=%lu", sig->created)); +if (sig->expires > 0) logmsg = string_cat(logmsg, + string_sprintf(" x=%lu", sig->expires)); +if (sig->bodylength > -1) logmsg = string_cat(logmsg, + string_sprintf(" l=%lu", sig->bodylength)); + +if ( !dkim_verify_status + || ( dkim_verify_status == dkim_exim_expand_query(DKIM_VERIFY_STATUS) + && dkim_verify_reason == dkim_exim_expand_query(DKIM_VERIFY_REASON) + ) ) switch (sig->verify_status) { case PDKIM_VERIFY_NONE: - logmsg = string_append(logmsg, &size, &ptr, 1, " [not verified]"); + logmsg = string_cat(logmsg, US" [not verified]"); break; case PDKIM_VERIFY_INVALID: - logmsg = string_append(logmsg, &size, &ptr, 1, " [invalid - "); + logmsg = string_cat(logmsg, US" [invalid - "); switch (sig->verify_ext_status) { case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: - logmsg = string_append(logmsg, &size, &ptr, 1, - "public key record (currently?) unavailable]"); + logmsg = string_cat(logmsg, + US"public key record (currently?) unavailable]"); break; case PDKIM_VERIFY_INVALID_BUFFER_SIZE: - logmsg = string_append(logmsg, &size, &ptr, 1, - "overlong public key record]"); + logmsg = string_cat(logmsg, US"overlong public key record]"); break; case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: - logmsg = string_append(logmsg, &size, &ptr, 1, - "syntax error in public key record]"); + logmsg = string_cat(logmsg, US"syntax error in public key record]"); break; - case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: - logmsg = string_append(logmsg, &size, &ptr, 1, - "signature tag missing or invalid]"); - break; + case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: + logmsg = string_cat(logmsg, US"signature tag missing or invalid]"); + break; - case PDKIM_VERIFY_INVALID_DKIM_VERSION: - logmsg = string_append(logmsg, &size, &ptr, 1, - "unsupported DKIM version]"); - break; + case PDKIM_VERIFY_INVALID_DKIM_VERSION: + logmsg = string_cat(logmsg, US"unsupported DKIM version]"); + break; default: - logmsg = string_append(logmsg, &size, &ptr, 1, - "unspecified problem]"); + logmsg = string_cat(logmsg, US"unspecified problem]"); } break; case PDKIM_VERIFY_FAIL: - logmsg = - string_append(logmsg, &size, &ptr, 1, " [verification failed - "); + logmsg = string_cat(logmsg, US" [verification failed - "); switch (sig->verify_ext_status) { case PDKIM_VERIFY_FAIL_BODY: - logmsg = string_append(logmsg, &size, &ptr, 1, - "body hash mismatch (body probably modified in transit)]"); + logmsg = string_cat(logmsg, + US"body hash mismatch (body probably modified in transit)]"); break; case PDKIM_VERIFY_FAIL_MESSAGE: - logmsg = string_append(logmsg, &size, &ptr, 1, - "signature did not verify (headers probably modified in transit)]"); + logmsg = string_cat(logmsg, + US"signature did not verify " + "(headers probably modified in transit)]"); break; default: - logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]"); + logmsg = string_cat(logmsg, US"unspecified reason]"); } break; case PDKIM_VERIFY_PASS: - logmsg = - string_append(logmsg, &size, &ptr, 1, " [verification succeeded]"); + logmsg = string_cat(logmsg, US" [verification succeeded]"); break; } +else + logmsg = string_append(logmsg, 5, + US" [", dkim_verify_status, US" - ", dkim_verify_reason, US"]"); + +log_write(0, LOG_MAIN, "%s", string_from_gstring(logmsg)); +return; +} + + +/* Log a line for each signature */ +void +dkim_exim_verify_log_all(void) +{ +pdkim_signature * sig; +for (sig = dkim_signatures; sig; sig = sig->next) dkim_exim_verify_log_sig(sig); +} + - logmsg[ptr] = '\0'; - log_write(0, LOG_MAIN, "DKIM: %s", logmsg); +void +dkim_exim_verify_finish(void) +{ +pdkim_signature * sig; +int rc; +gstring * g = NULL; +const uschar * errstr; - /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ +store_pool = POOL_PERM; - if (sig->domain) - dkim_signers = string_append_listele(dkim_signers, &dkim_signers_size, - &dkim_signers_ptr, ':', sig->domain); +/* Delete eventual previous signature chain */ - if (sig->identity) - dkim_signers = string_append_listele(dkim_signers, &dkim_signers_size, - &dkim_signers_ptr, ':', sig->identity); +dkim_signers = NULL; +dkim_signatures = NULL; - /* Process next signature */ +if (dkim_collect_error) + { + log_write(0, LOG_MAIN, + "DKIM: Error during validation, disabling signature verification: %.100s", + dkim_collect_error); + dkim_disable_verify = TRUE; + goto out; } +dkim_collect_input = FALSE; + +/* Finish DKIM operation and fetch link to signatures chain */ + +rc = pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures, &errstr); +if (rc != PDKIM_OK) + { + log_write(0, LOG_MAIN, "DKIM: validation error: %.100s%s%s", pdkim_errstr(rc), + errstr ? ": " : "", errstr ? errstr : US""); + goto out; + } + +/* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ + +for (sig = dkim_signatures; sig; sig = sig->next) + { + if (sig->domain) g = string_append_listele(g, ':', sig->domain); + if (sig->identity) g = string_append_listele(g, ':', sig->identity); + } + +if (g) dkim_signers = g->s; + out: store_pool = dkim_verify_oldpool; } -void -dkim_exim_acl_setup(uschar * id) + +/* Args as per dkim_exim_acl_run() below */ +static int +dkim_acl_call(uschar * id, gstring ** res_ptr, + uschar ** user_msgptr, uschar ** log_msgptr) +{ +int rc; +DEBUG(D_receive) + debug_printf("calling acl_smtp_dkim for dkim_cur_signer='%s'\n", id); + +rc = acl_check(ACL_WHERE_DKIM, NULL, acl_smtp_dkim, user_msgptr, log_msgptr); +dkim_exim_verify_log_sig(dkim_cur_sig); +*res_ptr = string_append_listele(*res_ptr, ':', dkim_verify_status); +return rc; +} + + + +/* For the given identity, run the DKIM ACL once for each matching signature. + +Arguments + id Identity to look for in dkim signatures + res_ptr ptr to growable string-list of status results, + appended to per ACL run + user_msgptr where to put a user error (for SMTP response) + log_msgptr where to put a logging message (not for SMTP response) + +Returns: OK access is granted by an ACCEPT verb + DISCARD access is granted by a DISCARD verb + FAIL access is denied + FAIL_DROP access is denied; drop the connection + DEFER can't tell at the moment + ERROR disaster +*/ + +int +dkim_exim_acl_run(uschar * id, gstring ** res_ptr, + uschar ** user_msgptr, uschar ** log_msgptr) { pdkim_signature * sig; uschar * cmp_val; +int rc = -1; -dkim_cur_sig = NULL; +dkim_verify_status = US"none"; +dkim_verify_reason = US""; dkim_cur_signer = id; if (dkim_disable_verify || !id || !dkim_verify_ctx) - return; + return OK; -/* Find signature to run ACL on */ +/* Find signatures to run ACL on */ for (sig = dkim_signatures; sig; sig = sig->next) if ( (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain) && strcmpic(cmp_val, id) == 0 ) { - dkim_cur_sig = sig; - /* The "dkim_domain" and "dkim_selector" expansion variables have - related globals, since they are used in the signing code too. - Instead of inventing separate names for verification, we set - them here. This is easy since a domain and selector is guaranteed - to be in a signature. The other dkim_* expansion items are - dynamically fetched from dkim_cur_sig at expansion time (see - function below). */ + related globals, since they are used in the signing code too. + Instead of inventing separate names for verification, we set + them here. This is easy since a domain and selector is guaranteed + to be in a signature. The other dkim_* expansion items are + dynamically fetched from dkim_cur_sig at expansion time (see + function below). */ + dkim_cur_sig = sig; dkim_signing_domain = US sig->domain; dkim_signing_selector = US sig->selector; dkim_key_length = sig->sighash.len * 8; - return; + + /* These two return static strings, so we can compare the addr + later to see if the ACL overwrote them. Check that when logging */ + + dkim_verify_status = dkim_exim_expand_query(DKIM_VERIFY_STATUS); + dkim_verify_reason = dkim_exim_expand_query(DKIM_VERIFY_REASON); + + if ((rc = dkim_acl_call(id, res_ptr, user_msgptr, log_msgptr)) != OK) + return rc; } + +if (rc != -1) + return rc; + +/* No matching sig found. Call ACL once anyway. */ + +dkim_cur_sig = NULL; +return dkim_acl_call(id, res_ptr, user_msgptr, log_msgptr); } @@ -346,7 +425,7 @@ switch (what) case DKIM_BODYLENGTH: return dkim_cur_sig->bodylength >= 0 - ? string_sprintf(OFF_T_FMT, (LONGLONG_T) dkim_cur_sig->bodylength) + ? string_sprintf("%ld", dkim_cur_sig->bodylength) : dkim_exim_expand_defaults(what); case DKIM_CANON_BODY: @@ -358,12 +437,12 @@ switch (what) } case DKIM_CANON_HEADERS: - switch (dkim_cur_sig->canon_headers) - { - case PDKIM_CANON_RELAXED: return US"relaxed"; - case PDKIM_CANON_SIMPLE: - default: return US"simple"; - } + switch (dkim_cur_sig->canon_headers) + { + case PDKIM_CANON_RELAXED: return US"relaxed"; + case PDKIM_CANON_SIMPLE: + default: return US"simple"; + } case DKIM_COPIEDHEADERS: return dkim_cur_sig->copiedheaders @@ -371,12 +450,12 @@ switch (what) case DKIM_CREATED: return dkim_cur_sig->created > 0 - ? string_sprintf("%llu", dkim_cur_sig->created) + ? string_sprintf("%lu", dkim_cur_sig->created) : dkim_exim_expand_defaults(what); case DKIM_EXPIRES: return dkim_cur_sig->expires > 0 - ? string_sprintf("%llu", dkim_cur_sig->expires) + ? string_sprintf("%lu", dkim_cur_sig->expires) : dkim_exim_expand_defaults(what); case DKIM_HEADERNAMES: @@ -453,36 +532,30 @@ switch (what) If a prefix is given, prepend it to the file for the calculations. */ -blob * +gstring * dkim_exim_sign(int fd, off_t off, uschar * prefix, struct ob_dkim * dkim, const uschar ** errstr) { const uschar * dkim_domain; int sep = 0; -uschar * seen_doms = NULL; -int seen_doms_size = 0; -int seen_doms_offset = 0; +gstring * seen_doms = NULL; pdkim_ctx ctx; pdkim_signature * sig; -blob * sigbuf = NULL; -int sigsize = 0; +gstring * sigbuf; int pdkim_rc; int sread; uschar buf[4096]; int save_errno = 0; int old_pool = store_pool; +uschar * errwhen; store_pool = POOL_MAIN; pdkim_init_context(&ctx, dkim->dot_stuffed, &dkim_exim_query_dns_txt); if (!(dkim_domain = expand_cstring(dkim->dkim_domain))) - { /* expansion error, do not send message. */ - log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " - "dkim_domain: %s", expand_string_message); - goto bad; - } + { errwhen = US"dkim_domain"; goto expand_bad; } /* Set $dkim_domain expansion variable to each unique domain in list. */ @@ -501,19 +574,14 @@ while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0))) 0, NULL, NULL, MCL_STRING, TRUE, NULL) == OK) continue; - seen_doms = string_append_listele(seen_doms, &seen_doms_size, - &seen_doms_offset, ':', dkim_signing_domain); + seen_doms = string_append_listele(seen_doms, ':', dkim_signing_domain); /* Set $dkim_selector expansion variable to each selector in list, for this domain. */ if (!(dkim_sel = expand_string(dkim->dkim_selector))) if (!(dkim_signing_selector = expand_string(dkim->dkim_selector))) - { - log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " - "dkim_selector: %s", expand_string_message); - goto bad; - } + { errwhen = US"dkim_selector"; goto expand_bad; } while ((dkim_signing_selector = string_nextinlist(&dkim_sel, &sel_sep, NULL, 0))) @@ -523,18 +591,14 @@ while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0))) uschar * dkim_sign_headers_expanded = NULL; uschar * dkim_private_key_expanded; uschar * dkim_hash_expanded; + uschar * dkim_identity_expanded = NULL; /* Get canonicalization to use */ dkim_canon_expanded = dkim->dkim_canon ? expand_string(dkim->dkim_canon) : US"relaxed"; - if (!dkim_canon_expanded) - { - /* expansion error, do not send message. */ - log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " - "dkim_canon: %s", expand_string_message); - goto bad; - } + if (!dkim_canon_expanded) /* expansion error, do not send message. */ + { errwhen = US"dkim_canon"; goto expand_bad; } if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0) pdkim_canon = PDKIM_CANON_RELAXED; @@ -548,23 +612,15 @@ while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0))) pdkim_canon = PDKIM_CANON_RELAXED; } - if (dkim->dkim_sign_headers) - if (!(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers))) - { - log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " - "dkim_sign_headers: %s", expand_string_message); - goto bad; - } - /* else pass NULL, which means default header list */ + if ( dkim->dkim_sign_headers + && !(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers))) + { errwhen = US"dkim_sign_header"; goto expand_bad; } + /* else pass NULL, which means default header list */ /* Get private key to use. */ if (!(dkim_private_key_expanded = expand_string(dkim->dkim_private_key))) - { - log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " - "dkim_private_key: %s", expand_string_message); - goto bad; - } + { errwhen = US"dkim_private_key"; goto expand_bad; } if ( Ustrlen(dkim_private_key_expanded) == 0 || Ustrcmp(dkim_private_key_expanded, "0") == 0 @@ -607,11 +663,13 @@ while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0))) } if (!(dkim_hash_expanded = expand_string(dkim->dkim_hash))) - { - log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " - "dkim_hash: %s", expand_string_message); - goto bad; - } + { errwhen = US"dkim_hash"; goto expand_bad; } + + if (dkim->dkim_identity) + if (!(dkim_identity_expanded = expand_string(dkim->dkim_identity))) + { errwhen = US"dkim_identity"; goto expand_bad; } + else if (!*dkim_identity_expanded) + dkim_identity_expanded = NULL; /*XXX so we currently nail signing to RSA + this hash. Need to extract algo from privkey and check for disallowed combos. */ @@ -627,7 +685,7 @@ while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0))) pdkim_set_optional(sig, CS dkim_sign_headers_expanded, - NULL, + CS dkim_identity_expanded, pdkim_canon, pdkim_canon, -1, 0, 0); @@ -665,23 +723,10 @@ if (sread == -1) if ((pdkim_rc = pdkim_feed_finish(&ctx, &sig, errstr)) != PDKIM_OK) goto pk_bad; -sigbuf = store_get(sizeof(blob)); -sigbuf->data = NULL; -sigbuf->len = 0; +for (sigbuf = NULL; sig; sig = sig->next) + sigbuf = string_append(sigbuf, 2, US sig->signature_header, US"\r\n"); -while (sig) - { - int len = sigbuf->len; - sigbuf->data = string_append(sigbuf->data, &sigsize, &len, 2, - US sig->signature_header, US"\r\n"); - sigbuf->len = len; - sig = sig->next; - } - -if (sigbuf->data) - sigbuf->data[sigbuf->len] = '\0'; -else - sigbuf->data = US""; +(void) string_from_gstring(sigbuf); CLEANUP: store_pool = old_pool; @@ -694,6 +739,12 @@ pk_bad: bad: sigbuf = NULL; goto CLEANUP; + +expand_bad: + log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand %s: %s", + errwhen, expand_string_message); + goto bad; } -#endif +# endif /*!MACRO_PREDEF*/ +#endif /*!DISABLE_DKIM*/