/* * Copyright (C) 2001 Nikos Mavroyanopoulos * * This file is part of GNUTLS. * * GNUTLS is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * GNUTLS is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG # warning MAX ALGORITHM PARAMS == 2, ok for RSA #endif /* KX mappings to PK algorithms */ typedef struct { KXAlgorithm kx_algorithm; PKAlgorithm pk_algorithm; } gnutls_pk_map; /* This table maps the Key exchange algorithms to * the certificate algorithms. Eg. if we have * RSA algorithm in the certificate then we can * use GNUTLS_KX_X509PKI_RSA or GNUTLS_KX_X509PKI_DHE_RSA. */ static const gnutls_pk_map pk_mappings[] = { {GNUTLS_KX_X509PKI_RSA, GNUTLS_PK_RSA}, {GNUTLS_KX_X509PKI_DHE_RSA, GNUTLS_PK_RSA}, {0} }; #define GNUTLS_PK_MAP_LOOP(b) \ const gnutls_pk_map *p; \ for(p = pk_mappings; p->kx_algorithm != 0; p++) { b ; } #define GNUTLS_PK_MAP_ALG_LOOP(a) \ GNUTLS_PK_MAP_LOOP( if(p->kx_algorithm == kx_algorithm) { a; break; }) /* returns the PKAlgorithm which is compatible with * the given KXAlgorithm. */ PKAlgorithm _gnutls_map_pk_get_pk(KXAlgorithm kx_algorithm) { PKAlgorithm ret = -1; GNUTLS_PK_MAP_ALG_LOOP(ret = p->pk_algorithm); return ret; } void gnutls_free_cert(gnutls_cert cert) { int n, i; switch (cert.subject_pk_algorithm) { case GNUTLS_PK_RSA: n = 2; /* the number of parameters in MPI* */ break; default: n = 0; } for (i = 0; i < n; i++) { _gnutls_mpi_release(&cert.params[i]); } gnutls_free_datum(&cert.raw); return; } /** * gnutls_x509pki_free_sc - Used to free an allocated x509 SERVER CREDENTIALS structure * @sc: is an &GNUTLS_X509PKI_CREDENTIALS structure. * * This structure is complex enough to manipulate directly thus * this helper function is provided in order to free (deallocate) * the structure. **/ void gnutls_x509pki_free_sc(GNUTLS_X509PKI_CREDENTIALS sc) { int i, j; for (i = 0; i < sc->ncerts; i++) { for (j = 0; j < sc->cert_list_length[i]; j++) { gnutls_free_cert(sc->cert_list[i][j]); } gnutls_free(sc->cert_list[i]); } gnutls_free(sc->cert_list_length); gnutls_free(sc->cert_list); for (j = 0; j < sc->ncas; j++) { gnutls_free_cert(sc->ca_list[j]); } gnutls_free(sc->ca_list); for (i = 0; i < sc->ncerts; i++) { _gnutls_free_private_key(sc->pkey[i]); } gnutls_free(sc->pkey); gnutls_free(sc->rdn_sequence.data); gnutls_free(sc); } #define MAX_FILE_SIZE 100*1024 #define CERT_SEP "-----BEGIN" /* Reads a base64 encoded certificate file */ static int read_cert_file(GNUTLS_X509PKI_CREDENTIALS res, char *certfile) { int siz, i, siz2; opaque *b64; char x[MAX_FILE_SIZE]; char *ptr; FILE *fd1; gnutls_datum tmp; int ret; fd1 = fopen(certfile, "r"); if (fd1 == NULL) return GNUTLS_E_UNKNOWN_ERROR; siz = fread(x, 1, sizeof(x), fd1); fclose(fd1); ptr = x; i = 1; res->cert_list[res->ncerts] = NULL; do { siz2 = _gnutls_fbase64_decode(ptr, siz, &b64); siz -= siz2; /* FIXME: this is not enough */ if (siz2 < 0) { gnutls_assert(); gnutls_free(b64); return GNUTLS_E_PARSING_ERROR; } ptr = strstr(ptr, CERT_SEP) + 1; res->cert_list[res->ncerts] = (gnutls_cert *) gnutls_realloc(res-> cert_list[res->ncerts], i * sizeof(gnutls_cert)); if (res->cert_list[res->ncerts] == NULL) { gnutls_assert(); gnutls_free(b64); return GNUTLS_E_MEMORY_ERROR; } /* set defaults to zero */ memset(&res->cert_list[res->ncerts][i - 1], 0, sizeof(gnutls_cert)); tmp.data = b64; tmp.size = siz2; if ((ret = _gnutls_cert2gnutlsCert(&res-> cert_list[res->ncerts][i - 1], tmp)) < 0) { gnutls_free(b64); gnutls_assert(); return ret; } gnutls_free(b64); i++; } while ((ptr = strstr(ptr, CERT_SEP)) != NULL); res->cert_list_length[res->ncerts] = i - 1; /* WE DO NOT CATCH OVERRUNS in gnutls_x509pki_set_key(). * This function should be called as many times as specified * in x509pki_allocate_sc(). */ res->ncerts++; return 0; } /* Reads a base64 encoded CA file (file contains multiple certificate * authorities). This is to be called once. */ static int read_ca_file(GNUTLS_X509PKI_CREDENTIALS res, char *cafile) { int siz, siz2, i; opaque *b64; char x[MAX_FILE_SIZE]; char *ptr; FILE *fd1; int ret; gnutls_datum tmp; fd1 = fopen(cafile, "r"); if (fd1 == NULL) { gnutls_assert(); return GNUTLS_E_UNKNOWN_ERROR; } siz = fread(x, 1, sizeof(x), fd1); fclose(fd1); ptr = x; res->ncas = 0; i = 1; res->ca_list = NULL; do { siz2 = _gnutls_fbase64_decode(ptr, siz, &b64); siz -= siz2; /* FIXME: this is not enough */ if (siz2 < 0) { gnutls_assert(); gnutls_free(b64); return GNUTLS_E_PARSING_ERROR; } ptr = strstr(ptr, CERT_SEP) + 1; res->ca_list = (gnutls_cert *) gnutls_realloc(res->ca_list, i * sizeof(gnutls_cert)); if (res->ca_list == NULL) { gnutls_assert(); gnutls_free(b64); return GNUTLS_E_MEMORY_ERROR; } memset(&res->ca_list[i - 1], 0, sizeof(gnutls_cert)); tmp.data = b64; tmp.size = siz2; if ((ret = _gnutls_cert2gnutlsCert(&res->ca_list[i - 1], tmp)) < 0) { gnutls_assert(); gnutls_free(b64); return ret; } gnutls_free(b64); i++; } while ((ptr = strstr(ptr, CERT_SEP)) != NULL); res->ncas = i - 1; return 0; } /* Reads a PEM encoded PKCS-1 RSA private key file */ static int read_key_file(GNUTLS_X509PKI_CREDENTIALS res, char *keyfile) { int siz, ret; opaque *b64; gnutls_datum tmp; char x[MAX_FILE_SIZE]; FILE *fd2; fd2 = fopen(keyfile, "r"); if (fd2 == NULL) return GNUTLS_E_UNKNOWN_ERROR; /* second file - PKCS-1 private key */ siz = fread(x, 1, sizeof(x), fd2); fclose(fd2); siz = _gnutls_fbase64_decode(x, siz, &b64); if (siz < 0) { gnutls_assert(); gnutls_free(b64); return GNUTLS_E_PARSING_ERROR; } tmp.data = b64; tmp.size = siz; if ((ret = _gnutls_pkcs1key2gnutlsKey(&res->pkey[res->ncerts], tmp)) < 0) { gnutls_assert(); gnutls_free(b64); return ret; } gnutls_free(b64); return 0; } /** * gnutls_x509pki_allocate_sc - Used to allocate an x509 SERVER CREDENTIALS structure * @res: is a pointer to an &GNUTLS_X509PKI_CREDENTIALS structure. * @ncerts: this is the number of certificate/private key pair you're going to use. * This should be 1 in common sites. * * This structure is complex enough to manipulate directly thus * this helper function is provided in order to allocate * the structure. **/ int gnutls_x509pki_allocate_sc(GNUTLS_X509PKI_CREDENTIALS * res, int ncerts) { *res = gnutls_calloc(1, sizeof(X509PKI_CREDENTIALS_INT)); if (*res == NULL) return GNUTLS_E_MEMORY_ERROR; (*res)->ncerts = 0; /* this is right - set_key() increments it */ if (ncerts > 0) { (*res)->cert_list = (gnutls_cert **) gnutls_malloc(ncerts * sizeof(gnutls_cert *)); if ((*res)->cert_list == NULL) { gnutls_free(*res); return GNUTLS_E_MEMORY_ERROR; } (*res)->cert_list_length = (int *) gnutls_malloc(ncerts * sizeof(int *)); if ((*res)->cert_list_length == NULL) { gnutls_free(*res); gnutls_free((*res)->cert_list); return GNUTLS_E_MEMORY_ERROR; } (*res)->pkey = gnutls_malloc(ncerts * sizeof(gnutls_private_key)); if ((*res)->pkey == NULL) { gnutls_free(*res); gnutls_free((*res)->cert_list); gnutls_free((*res)->cert_list_length); return GNUTLS_E_MEMORY_ERROR; } } return 0; } /** * gnutls_x509pki_set_key_file - Used to set keys in a GNUTLS_X509PKI_CREDENTIALS structure * @res: is an &GNUTLS_X509PKI_CREDENTIALS structure. * @CERTFILE: is a PEM encoded file containing the certificate list (path) for * the specified private key * @KEYFILE: is a PEM encoded file containing a private key * * This function sets a certificate/private key pair in the * GNUTLS_X509PKI_CREDENTIALS structure. This function may be called * more than once (in case multiple keys/certificates exist for the * server). * * Currently only PKCS-1 PEM encoded RSA private keys are accepted by * this function. * **/ int gnutls_x509pki_set_key_file(GNUTLS_X509PKI_CREDENTIALS res, char *CERTFILE, char *KEYFILE) { int ret; /* this should be first */ if ((ret = read_key_file(res, KEYFILE)) < 0) return ret; if ((ret = read_cert_file(res, CERTFILE)) < 0) return ret; return 0; } /** * gnutls_x509pki_set_trust_file - Used to set trusted CAs in a GNUTLS_X509PKI_CREDENTIALS structure * @res: is an &GNUTLS_X509PKI_CREDENTIALS structure. * @CAFILE: is a PEM encoded file containing trusted CAs * @CRLFILE: is a PEM encoded file containing CRLs (ignored for now) * * This function sets the trusted CAs in order to verify client * certificates. **/ int gnutls_x509pki_set_trust_file(GNUTLS_X509PKI_CREDENTIALS res, char *CAFILE, char *CRLFILE) { int ret, size, i; opaque *pdata; gnutls_datum tmp; if ((ret = read_ca_file(res, CAFILE)) < 0) return ret; /* Generate the RDN sequence * This will be sent to clients when a certificate * request message is sent. */ /* FIXME: in case of a client it is not needed * to do that. This would save time and memory. * However we don't have that information available * here. */ size = 0; for (i = 0; i < res->ncas; i++) { if ((ret = _gnutls_find_dn(&tmp, &res->ca_list[i])) < 0) { gnutls_assert(); return ret; } size += (2 + tmp.size); } res->rdn_sequence.data = gnutls_malloc(size); if (res->rdn_sequence.data == NULL) { gnutls_assert(); return GNUTLS_E_MEMORY_ERROR; } res->rdn_sequence.size = size; pdata = res->rdn_sequence.data; for (i = 0; i < res->ncas; i++) { if ((ret = _gnutls_find_dn(&tmp, &res->ca_list[i])) < 0) { gnutls_free(res->rdn_sequence.data); res->rdn_sequence.size = 0; res->rdn_sequence.data = NULL; gnutls_assert(); return ret; } WRITEdatum16(pdata, tmp); pdata += (2 + tmp.size); } return 0; } /** * gnutls_x509pki_set_dh_bits - Used to set the bits for a DHE_* ciphersuite * @state: is a &GNUTLS_STATE structure. * @bits: is the number of bits * * This function sets the number of bits, for use in a Diffie Hellman key exchange. * This value will only be used in case of DHE ciphersuite. * **/ void gnutls_x509pki_set_dh_bits(GNUTLS_STATE state, int bits) { state->gnutls_internals.x509pki_dhe_bits = bits; } static int _read_rsa_params(opaque * der, int dersize, MPI * params) { opaque str[MAX_X509_CERT_SIZE]; int len, result; node_asn *spk; if (asn1_create_structure (_gnutls_get_pkcs(), "PKCS-1.RSAPublicKey", &spk, "rsa_public_key") != ASN_OK) { gnutls_assert(); return GNUTLS_E_ASN1_ERROR; } result = asn1_get_der(spk, der, dersize); if (result != ASN_OK) { gnutls_assert(); asn1_delete_structure(spk); return GNUTLS_E_ASN1_PARSING_ERROR; } len = sizeof(str) - 1; result = asn1_read_value(spk, "rsa_public_key.modulus", str, &len); if (result != ASN_OK) { gnutls_assert(); asn1_delete_structure(spk); return GNUTLS_E_ASN1_PARSING_ERROR; } if (_gnutls_mpi_scan(¶ms[0], str, &len) != 0) { gnutls_assert(); asn1_delete_structure(spk); return GNUTLS_E_MPI_SCAN_FAILED; } len = sizeof(str) - 1; result = asn1_read_value(spk, "rsa_public_key.publicExponent", str, &len); if (result != ASN_OK) { gnutls_assert(); _gnutls_mpi_release(¶ms[0]); asn1_delete_structure(spk); return GNUTLS_E_ASN1_PARSING_ERROR; } if (_gnutls_mpi_scan(¶ms[1], str, &len) != 0) { gnutls_assert(); _gnutls_mpi_release(¶ms[0]); asn1_delete_structure(spk); return GNUTLS_E_MPI_SCAN_FAILED; } asn1_delete_structure(spk); return 0; } #define _READ(a, aa, b, c, d, e, res, f) \ result = _IREAD(a, aa, b, c, d, e, res, sizeof(res), f); \ if (result<0) return result; \ if (result==1) continue int _IREAD(node_asn * rasn, char *name3, char *rstr, char *OID, char *ANAME, char *TYPE, char *res, int res_size, int CHOICE) { char name2[256]; int result, len; char str[1024]; node_asn *tmpasn; if (strcmp(rstr, OID) == 0) { strcpy(str, "PKIX1Implicit88."); strcat(str, ANAME); strcpy(name2, "temp-structure-"); strcat(name2, TYPE); if ((result = asn1_create_structure(_gnutls_get_pkix(), str, &tmpasn, name2)) != ASN_OK) { gnutls_assert(); return GNUTLS_E_ASN1_ERROR; } len = sizeof(str) - 1; if ((result = asn1_read_value(rasn, name3, str, &len)) != ASN_OK) { asn1_delete_structure(tmpasn); return 1; } if ((result = asn1_get_der(tmpasn, str, len)) != ASN_OK) { asn1_delete_structure(tmpasn); return 1; } strcpy(name3, name2); len = sizeof(str) - 1; if ((result = asn1_read_value(tmpasn, name3, str, &len)) != ASN_OK) { /* CHOICE */ asn1_delete_structure(tmpasn); return 1; } if (CHOICE == 0) { str[len] = 0; strcpy(res, str); asn1_delete_structure(tmpasn); } else { /* CHOICE */ str[len] = 0; strcat(name3, "."); strcat(name3, str); len = sizeof(str) - 1; if ((result = asn1_read_value(tmpasn, name3, str, &len)) != ASN_OK) { asn1_delete_structure(tmpasn); return 1; } str[len] = 0; if (strlen(str) < res_size) strcpy(res, str); asn1_delete_structure(tmpasn); } } return 0; } /* this function will convert up to 3 digit * numbers to characters. */ void _gnutls_int2str(int k, char *data) { if (k > 999) data[0] = 0; else sprintf(data, "%d", k); } /* This function will attempt to read a Name * ASN.1 structure. (Taken from Fabio's samples!) * * FIXME: These functions need carefull auditing * (they're complex enough) * --nmav */ int _gnutls_get_name_type(node_asn * rasn, char *root, gnutls_DN * dn) { int k, k2, result, len; char name[128], str[1024], name2[128], counter[MAX_INT_DIGITS], name3[128]; k = 0; do { k++; strcpy(name, root); strcat(name, ".rdnSequence.?"); _gnutls_int2str(k, counter); strcat(name, counter); len = sizeof(str) - 1; result = asn1_read_value(rasn, name, str, &len); /* move to next */ if (result == ASN_ELEMENT_NOT_FOUND) break; if (result != ASN_VALUE_NOT_FOUND) { gnutls_assert(); return GNUTLS_E_ASN1_PARSING_ERROR; } k2 = 0; do { k2++; strcpy(name2, name); strcat(name2, ".?"); _gnutls_int2str(k2, counter); strcat(name2, counter); len = sizeof(str) - 1; result = asn1_read_value(rasn, name2, str, &len); if (result == ASN_ELEMENT_NOT_FOUND) break; if (result != ASN_VALUE_NOT_FOUND) { gnutls_assert(); return GNUTLS_E_ASN1_PARSING_ERROR; } strcpy(name3, name2); strcat(name3, ".type"); len = sizeof(str) - 1; result = asn1_read_value(rasn, name3, str, &len); if (result == ASN_ELEMENT_NOT_FOUND) break; else if (result != ASN_OK) { gnutls_assert(); return GNUTLS_E_ASN1_PARSING_ERROR; } strcpy(name3, name2); strcat(name3, ".value"); if (result == ASN_OK) { #ifdef DEBUG # warning " FIX COUNTRY HERE" #endif _READ(rasn, name3, str, "2 5 4 6", "X520OrganizationName", "countryName", dn->country, 1); _READ(rasn, name3, str, "2 5 4 10", "X520OrganizationName", "OrganizationName", dn->organization, 1); _READ(rasn, name3, str, "2 5 4 11", "X520OrganizationalUnitName", "OrganizationalUnitName", dn->organizational_unit_name, 1); _READ(rasn, name3, str, "2 5 4 3", "X520CommonName", "CommonName", dn->common_name, 1); _READ(rasn, name3, str, "2 5 4 7", "X520LocalityName", "LocalityName", dn->locality_name, 1); _READ(rasn, name3, str, "2 5 4 8", "X520StateOrProvinceName", "StateOrProvinceName", dn->state_or_province_name, 1); _READ(rasn, name3, str, "1 2 840 113549 1 9 1", "Pkcs9email", "emailAddress", dn->email, 0); } } while (1); } while (1); if (result == ASN_ELEMENT_NOT_FOUND) return 0; else return GNUTLS_E_ASN1_PARSING_ERROR; } #define MAX_TIME 1024 time_t _gnutls_get_time(node_asn * c2, char *root, char *when) { opaque ttime[MAX_TIME]; char name[1024]; time_t ctime; int len, result; strcpy(name, root); strcat(name, ".tbsCertificate.validity."); strcat(name, when); len = sizeof(ttime) - 1; if ((result = asn1_read_value(c2, name, ttime, &len)) < 0) { gnutls_assert(); return (time_t) (-1); } /* CHOICE */ strcpy(name, root); if (strcmp(ttime, "GeneralizedTime") == 0) { strcat(name, ".tbsCertificate.validity."); strcat(name, when); strcat(name, ".generalTime"); len = sizeof(ttime) - 1; result = asn1_read_value(c2, name, ttime, &len); if (result == ASN_OK) ctime = _gnutls_generalTime2gtime(ttime); } else { /* UTCTIME */ strcat(name, ".tbsCertificate.validity."); strcat(name, when); strcat(name, ".utcTime"); len = sizeof(ttime) - 1; result = asn1_read_value(c2, name, ttime, &len); if (result == ASN_OK) ctime = _gnutls_utcTime2gtime(ttime); } if (result != ASN_OK) { gnutls_assert(); return (time_t) (-1); } return ctime; } int _gnutls_get_version(node_asn * c2, char *root) { opaque gversion[5]; char name[1024]; int len, result; strcpy(name, root); strcat(name, ".tbsCertificate.version"); len = sizeof(gversion) - 1; if ((result = asn1_read_value(c2, name, gversion, &len)) < 0) { gnutls_assert(); return (-1); } return (int) gversion[0] + 1; } #ifdef DEBUG # warning FIX THIS FOR DSS #endif /* This function will convert a der certificate, to a format * (structure) that gnutls can understand and use. Actually the * important thing on this function is that it extracts the * certificate's (public key) parameters. */ int _gnutls_cert2gnutlsCert(gnutls_cert * gCert, gnutls_datum derCert) { int result; node_asn *c2; opaque str[MAX_X509_CERT_SIZE]; int len = sizeof(str); memset(gCert, 0, sizeof(gnutls_cert)); gCert->valid = 1; if (gnutls_set_datum(&gCert->raw, derCert.data, derCert.size) < 0) { gnutls_assert(); return GNUTLS_E_MEMORY_ERROR; } if (asn1_create_structure (_gnutls_get_pkix(), "PKIX1Implicit88.Certificate", &c2, "certificate2") != ASN_OK) { gnutls_assert(); gnutls_free_datum( &gCert->raw); return GNUTLS_E_ASN1_ERROR; } result = asn1_get_der(c2, derCert.data, derCert.size); if (result != ASN_OK) { /* couldn't decode DER */ #ifdef DEBUG _gnutls_log("Decoding error %d\n", result); #endif gnutls_assert(); asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return GNUTLS_E_ASN1_PARSING_ERROR; } len = sizeof(str) - 1; result = asn1_read_value (c2, "certificate2.tbsCertificate.subjectPublicKeyInfo.algorithm.algorithm", str, &len); if (result != ASN_OK) { gnutls_assert(); asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return GNUTLS_E_ASN1_PARSING_ERROR; } if (strcmp(str, "1 2 840 113549 1 1 1") == 0) { /* pkix-1 1 - RSA */ /* params[0] is the modulus, * params[1] is the exponent */ gCert->subject_pk_algorithm = GNUTLS_PK_RSA; len = sizeof(str) - 1; result = asn1_read_value (c2, "certificate2.tbsCertificate.subjectPublicKeyInfo.subjectPublicKey", str, &len); if (result != ASN_OK) { gnutls_assert(); asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return GNUTLS_E_ASN1_PARSING_ERROR; } if ((sizeof(gCert->params) / sizeof(MPI)) < 2) { gnutls_assert(); /* internal error. Increase the MPIs in params */ asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return GNUTLS_E_UNKNOWN_ERROR; } if ((result = _read_rsa_params(str, len / 8, gCert->params)) < 0) { gnutls_assert(); asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return result; } } else { /* other types like DH, DSA * currently not supported */ gnutls_assert(); #ifdef DEBUG _gnutls_log("ALGORITHM: %s\n", str); asn1_delete_structure(c2); return GNUTLS_E_UNIMPLEMENTED_FEATURE; #endif gCert->subject_pk_algorithm = GNUTLS_PK_UNKNOWN; } len = sizeof(gCert->signature); result = asn1_read_value (c2, "certificate2.signature", gCert->signature, &len); if ((len % 8) != 0) { gnutls_assert(); asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return GNUTLS_E_UNIMPLEMENTED_FEATURE; } len /= 8; /* convert to bytes */ gCert->signature_size = len; gCert->expiration_time = _gnutls_get_time(c2, "certificate2", "notAfter"); gCert->activation_time = _gnutls_get_time(c2, "certificate2", "notBefore"); gCert->version = _gnutls_get_version(c2, "certificate2"); if ((result = _gnutls_get_ext_type(c2, "certificate2.tbsCertificate.extensions", gCert)) < 0) { gnutls_assert(); asn1_delete_structure(c2); gnutls_free_datum( &gCert->raw); return result; } asn1_delete_structure(c2); gCert->valid = 0; /* if we got until here * the certificate is valid. */ return 0; } /* Returns 0 if it's ok to use the KXAlgorithm with this cert * (using KeyUsage field). */ int _gnutls_check_x509pki_key_usage(const gnutls_cert * cert, KXAlgorithm alg) { if (_gnutls_map_kx_get_cred(alg) == GNUTLS_X509PKI) { switch (alg) { case GNUTLS_KX_X509PKI_RSA: if (cert->keyUsage != 0) { if (! (cert-> keyUsage & GNUTLS_X509KEY_KEY_ENCIPHERMENT)) return GNUTLS_E_X509_KEY_USAGE_VIOLATION; else return 0; } return 0; case GNUTLS_KX_X509PKI_DHE_RSA: if (cert->keyUsage != 0) { if (! (cert-> keyUsage & GNUTLS_X509KEY_DIGITAL_SIGNATURE)) return GNUTLS_E_X509_KEY_USAGE_VIOLATION; else return 0; } return 0; default: gnutls_assert(); return GNUTLS_E_X509_KEY_USAGE_VIOLATION; } } return 0; } /* returns the KX algorithms that are supported by a * certificate. (Eg a certificate with RSA params, supports * GNUTLS_KX_X509PKI_RSA algorithm). * This function also uses the KeyUsage field of the certificate * extensions in order to disable unneded algorithms. */ int _gnutls_cert_supported_kx(const gnutls_cert * cert, KXAlgorithm ** alg, int *alg_size) { KXAlgorithm kx; int i; PKAlgorithm pk; KXAlgorithm kxlist[255]; i = 0; for (kx = 0; kx < 255; kx++) { pk = _gnutls_map_pk_get_pk(kx); if (pk == cert->subject_pk_algorithm) { if (_gnutls_check_x509pki_key_usage(cert, kx) == 0) { kxlist[i] = kx; i++; } } } *alg = gnutls_calloc(1, sizeof(KXAlgorithm) * i); if (*alg == NULL) return GNUTLS_E_MEMORY_ERROR; *alg_size = i; memcpy(*alg, kxlist, i * sizeof(KXAlgorithm)); return 0; } /** * gnutls_x509pki_server_set_cert_request - Used to set whether to request a client certificate * @state: is an &GNUTLS_STATE structure. * @req: is one of GNUTLS_CERT_REQUEST, GNUTLS_CERT_REQUIRE * * This function specifies if we (in case of a server) are going * to send a certificate request message to the client. If 'req' * is GNUTLS_CERT_REQUIRE then the server will return an error if * the peer does not provide a certificate. If you do not * call this function then the client will not be asked to * send a certificate. **/ void gnutls_x509pki_server_set_cert_request(GNUTLS_STATE state, CertificateRequest req) { state->gnutls_internals.send_cert_req = req; } /** * gnutls_x509pki_set_client_cert_callback - Used to set a callback while selecting the proper (client) certificate * @state: is a &GNUTLS_STATE structure. * @func: is the callback function * * The callback's function form is: * int (*callback)(gnutls_datum *client_cert, int ncerts, gnutls_datum* req_ca_cert, int nreqs); * * 'client_cert' contains 'ncerts' gnutls_datum structures which hold * the DER encoded X.509 certificates of the client. * * 'req_ca_cert' contains a list with the CA names that the server * considers trusted. Normaly we should send a certificate that is signed * by one of these CAs. These names are DER encoded. To get a more * meaningful value use the function gnutls_x509pki_extract_dn(). * * This function specifies what we, in case of a client, are going * to do when we have to send a certificate. If this callback * function is not provided then gnutls will automaticaly try to * find an appropriate certificate to send. * * If the callback function is provided then gnutls will call it * once with NULL parameters. If the callback function returns * a positive or zero number then gnutls will attempt to automaticaly * choose the appropriate certificate. If gnutls fails to find an appropriate * certificate, then it will call the callback function again with the * appropriate parameters. * * In case the callback returned a negative number then gnutls will * not attempt to choose the appropriate certificate and will call again * the callback function with the appropriate parameters, and rely * only to the return value of the callback function. * * The callback function should return the index of the certificate * choosen by the user. -1 indicates that the user * does not want to use client authentication. * * This function returns 0 on success. **/ void gnutls_x509pki_set_client_cert_callback(GNUTLS_STATE state, x509pki_client_cert_callback_func * func) { state->gnutls_internals.client_cert_callback = func; } /** * gnutls_x509pki_set_server_cert_callback - Used to set a callback while selecting the proper (server) certificate * @state: is a &GNUTLS_STATE structure. * @func: is the callback function * * The callback's function form is: * int (*callback)(gnutls_datum *server_cert, int ncerts); * * 'server_cert' contains 'ncerts' gnutls_datum structures which hold * the DER encoded X.509 certificates of the server. * * This function specifies what we, in case of a server, are going * to do when we have to send a certificate. If this callback * function is not provided then gnutls will automaticaly try to * find an appropriate certificate to send. (actually send the first in the list) * * In case the callback returned a negative number then gnutls will * not attempt to choose the appropriate certificate and the caller function * will fail. * * The callback function will only be called once per handshake. * The callback function should return the index of the certificate * choosen by the server. -1 indicates an error. * **/ void gnutls_x509pki_set_server_cert_callback(GNUTLS_STATE state, x509pki_server_cert_callback_func * func) { state->gnutls_internals.server_cert_callback = func; }