diff options
Diffstat (limited to 'libcli/auth/spnego_parse.c')
-rw-r--r-- | libcli/auth/spnego_parse.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/libcli/auth/spnego_parse.c b/libcli/auth/spnego_parse.c new file mode 100644 index 0000000..f7f19b1 --- /dev/null +++ b/libcli/auth/spnego_parse.c @@ -0,0 +1,446 @@ +/* + Unix SMB/CIFS implementation. + + RFC2478 Compliant SPNEGO implementation + + Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003 + + This program 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 3 of the License, or + (at your option) any later version. + + This program 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, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "../libcli/auth/spnego.h" +#include "../lib/util/asn1.h" + +static bool read_negTokenInit(struct asn1_data *asn1, TALLOC_CTX *mem_ctx, + struct spnego_negTokenInit *token) +{ + ZERO_STRUCTP(token); + + if (!asn1_start_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_start_tag(asn1, ASN1_SEQUENCE(0))) return false; + + while (asn1_tag_remaining(asn1) > 0) { + int i; + uint8_t context; + + if (!asn1_peek_uint8(asn1, &context)) { + asn1_set_error(asn1); + break; + } + + switch (context) { + /* Read mechTypes */ + case ASN1_CONTEXT(0): { + const char **mechTypes; + + if (!asn1_start_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_start_tag(asn1, ASN1_SEQUENCE(0))) return false; + + mechTypes = talloc(mem_ctx, const char *); + if (mechTypes == NULL) { + asn1_set_error(asn1); + return false; + } + for (i = 0; asn1_tag_remaining(asn1) > 0; i++) { + char *oid; + const char **p; + p = talloc_realloc(mem_ctx, + mechTypes, + const char *, i+2); + if (p == NULL) { + talloc_free(mechTypes); + asn1_set_error(asn1); + return false; + } + mechTypes = p; + + if (!asn1_read_OID(asn1, mechTypes, &oid)) return false; + mechTypes[i] = oid; + } + mechTypes[i] = NULL; + token->mechTypes = mechTypes; + + asn1_end_tag(asn1); + asn1_end_tag(asn1); + break; + } + /* Read reqFlags */ + case ASN1_CONTEXT(1): + if (!asn1_start_tag(asn1, ASN1_CONTEXT(1))) return false; + if (!asn1_read_BitString(asn1, mem_ctx, &token->reqFlags, + &token->reqFlagsPadding)) return false; + if (!asn1_end_tag(asn1)) return false; + break; + /* Read mechToken */ + case ASN1_CONTEXT(2): + if (!asn1_start_tag(asn1, ASN1_CONTEXT(2))) return false; + if (!asn1_read_OctetString(asn1, mem_ctx, &token->mechToken)) return false; + if (!asn1_end_tag(asn1)) return false; + break; + /* Read mecListMIC */ + case ASN1_CONTEXT(3): + { + uint8_t type_peek; + if (!asn1_start_tag(asn1, ASN1_CONTEXT(3))) return false; + if (!asn1_peek_uint8(asn1, &type_peek)) { + asn1_set_error(asn1); + break; + } + if (type_peek == ASN1_OCTET_STRING) { + if (!asn1_read_OctetString(asn1, mem_ctx, + &token->mechListMIC)) return false; + } else { + /* RFC 2478 says we have an Octet String here, + but W2k sends something different... */ + char *mechListMIC; + if (!asn1_start_tag(asn1, ASN1_SEQUENCE(0))) return false; + if (!asn1_start_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_read_GeneralString(asn1, mem_ctx, &mechListMIC)) return false; + if (!asn1_end_tag(asn1)) return false; + if (!asn1_end_tag(asn1)) return false; + + token->targetPrincipal = mechListMIC; + } + if (!asn1_end_tag(asn1)) return false; + break; + } + default: + asn1_set_error(asn1); + break; + } + } + + if (!asn1_end_tag(asn1)) return false; + if (!asn1_end_tag(asn1)) return false; + + return !asn1_has_error(asn1); +} + +static bool write_negTokenInit(struct asn1_data *asn1, struct spnego_negTokenInit *token) +{ + if (!asn1_push_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_push_tag(asn1, ASN1_SEQUENCE(0))) return false; + + /* Write mechTypes */ + if (token->mechTypes && *token->mechTypes) { + int i; + + if (!asn1_push_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_push_tag(asn1, ASN1_SEQUENCE(0))) return false; + for (i = 0; token->mechTypes[i]; i++) { + if (!asn1_write_OID(asn1, token->mechTypes[i])) return false; + } + if (!asn1_pop_tag(asn1)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + /* write reqFlags */ + if (token->reqFlags.length > 0) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(1))) return false; + if (!asn1_write_BitString(asn1, token->reqFlags.data, + token->reqFlags.length, + token->reqFlagsPadding)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + /* write mechToken */ + if (token->mechToken.data) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(2))) return false; + if (!asn1_write_OctetString(asn1, token->mechToken.data, + token->mechToken.length)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + /* write mechListMIC */ + if (token->mechListMIC.data) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(3))) return false; +#if 0 + /* This is what RFC 2478 says ... */ + asn1_write_OctetString(asn1, token->mechListMIC.data, + token->mechListMIC.length); +#else + /* ... but unfortunately this is what Windows + sends/expects */ + if (!asn1_push_tag(asn1, ASN1_SEQUENCE(0))) return false; + if (!asn1_push_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_push_tag(asn1, ASN1_GENERAL_STRING)) return false; + if (!asn1_write(asn1, token->mechListMIC.data, + token->mechListMIC.length)) return false; + if (!asn1_pop_tag(asn1)) return false; + if (!asn1_pop_tag(asn1)) return false; + if (!asn1_pop_tag(asn1)) return false; +#endif + if (!asn1_pop_tag(asn1)) return false; + } + + if (!asn1_pop_tag(asn1)) return false; + if (!asn1_pop_tag(asn1)) return false; + + return !asn1_has_error(asn1); +} + +static bool read_negTokenTarg(struct asn1_data *asn1, TALLOC_CTX *mem_ctx, + struct spnego_negTokenTarg *token) +{ + ZERO_STRUCTP(token); + + if (!asn1_start_tag(asn1, ASN1_CONTEXT(1))) return false; + if (!asn1_start_tag(asn1, ASN1_SEQUENCE(0))) return false; + + while (asn1_tag_remaining(asn1) > 0) { + uint8_t context; + uint8_t neg_result; + char *oid; + + if (!asn1_peek_uint8(asn1, &context)) { + asn1_set_error(asn1); + break; + } + + switch (context) { + case ASN1_CONTEXT(0): + if (!asn1_start_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_start_tag(asn1, ASN1_ENUMERATED)) return false; + if (!asn1_read_uint8(asn1, &neg_result)) return false; + token->negResult = neg_result; + if (!asn1_end_tag(asn1)) return false; + if (!asn1_end_tag(asn1)) return false; + break; + case ASN1_CONTEXT(1): + if (!asn1_start_tag(asn1, ASN1_CONTEXT(1))) return false; + if (!asn1_read_OID(asn1, mem_ctx, &oid)) return false; + token->supportedMech = oid; + if (!asn1_end_tag(asn1)) return false; + break; + case ASN1_CONTEXT(2): + if (!asn1_start_tag(asn1, ASN1_CONTEXT(2))) return false; + if (!asn1_read_OctetString(asn1, mem_ctx, &token->responseToken)) return false; + if (!asn1_end_tag(asn1)) return false; + break; + case ASN1_CONTEXT(3): + if (!asn1_start_tag(asn1, ASN1_CONTEXT(3))) return false; + if (!asn1_read_OctetString(asn1, mem_ctx, &token->mechListMIC)) return false; + if (!asn1_end_tag(asn1)) return false; + break; + default: + asn1_set_error(asn1); + break; + } + } + + if (!asn1_end_tag(asn1)) return false; + if (!asn1_end_tag(asn1)) return false; + + return !asn1_has_error(asn1); +} + +static bool write_negTokenTarg(struct asn1_data *asn1, struct spnego_negTokenTarg *token) +{ + if (!asn1_push_tag(asn1, ASN1_CONTEXT(1))) return false; + if (!asn1_push_tag(asn1, ASN1_SEQUENCE(0))) return false; + + if (token->negResult != SPNEGO_NONE_RESULT) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(0))) return false; + if (!asn1_write_enumerated(asn1, token->negResult)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + if (token->supportedMech) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(1))) return false; + if (!asn1_write_OID(asn1, token->supportedMech)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + if (token->responseToken.data) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(2))) return false; + if (!asn1_write_OctetString(asn1, token->responseToken.data, + token->responseToken.length)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + if (token->mechListMIC.data) { + if (!asn1_push_tag(asn1, ASN1_CONTEXT(3))) return false; + if (!asn1_write_OctetString(asn1, token->mechListMIC.data, + token->mechListMIC.length)) return false; + if (!asn1_pop_tag(asn1)) return false; + } + + if (!asn1_pop_tag(asn1)) return false; + if (!asn1_pop_tag(asn1)) return false; + + return !asn1_has_error(asn1); +} + +ssize_t spnego_read_data(TALLOC_CTX *mem_ctx, DATA_BLOB data, struct spnego_data *token) +{ + struct asn1_data *asn1; + ssize_t ret = -1; + uint8_t context; + + ZERO_STRUCTP(token); + + if (data.length == 0) { + return ret; + } + + asn1 = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH); + if (asn1 == NULL) { + return -1; + } + + if (!asn1_load(asn1, data)) goto err; + + if (!asn1_peek_uint8(asn1, &context)) { + asn1_set_error(asn1); + } else { + switch (context) { + case ASN1_APPLICATION(0): + if (!asn1_start_tag(asn1, ASN1_APPLICATION(0))) goto err; + if (!asn1_check_OID(asn1, OID_SPNEGO)) goto err; + if (read_negTokenInit(asn1, mem_ctx, &token->negTokenInit)) { + token->type = SPNEGO_NEG_TOKEN_INIT; + } + if (!asn1_end_tag(asn1)) goto err; + break; + case ASN1_CONTEXT(1): + if (read_negTokenTarg(asn1, mem_ctx, &token->negTokenTarg)) { + token->type = SPNEGO_NEG_TOKEN_TARG; + } + break; + default: + asn1_set_error(asn1); + break; + } + } + + if (!asn1_has_error(asn1)) { + ret = asn1_current_ofs(asn1); + } + + err: + + asn1_free(asn1); + + return ret; +} + +ssize_t spnego_write_data(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, struct spnego_data *spnego) +{ + struct asn1_data *asn1 = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH); + ssize_t ret = -1; + + if (asn1 == NULL) { + return -1; + } + + switch (spnego->type) { + case SPNEGO_NEG_TOKEN_INIT: + if (!asn1_push_tag(asn1, ASN1_APPLICATION(0))) goto err; + if (!asn1_write_OID(asn1, OID_SPNEGO)) goto err; + if (!write_negTokenInit(asn1, &spnego->negTokenInit)) goto err; + if (!asn1_pop_tag(asn1)) goto err; + break; + case SPNEGO_NEG_TOKEN_TARG: + write_negTokenTarg(asn1, &spnego->negTokenTarg); + break; + default: + asn1_set_error(asn1); + break; + } + + if (!asn1_extract_blob(asn1, mem_ctx, blob)) { + goto err; + } + + ret = asn1_current_ofs(asn1); + + err: + + asn1_free(asn1); + + return ret; +} + +bool spnego_free_data(struct spnego_data *spnego) +{ + bool ret = true; + + if (!spnego) goto out; + + switch(spnego->type) { + case SPNEGO_NEG_TOKEN_INIT: + if (spnego->negTokenInit.mechTypes) { + talloc_free(discard_const(spnego->negTokenInit.mechTypes)); + } + data_blob_free(&spnego->negTokenInit.reqFlags); + data_blob_free(&spnego->negTokenInit.mechToken); + data_blob_free(&spnego->negTokenInit.mechListMIC); + talloc_free(spnego->negTokenInit.targetPrincipal); + break; + case SPNEGO_NEG_TOKEN_TARG: + if (spnego->negTokenTarg.supportedMech) { + talloc_free(discard_const(spnego->negTokenTarg.supportedMech)); + } + data_blob_free(&spnego->negTokenTarg.responseToken); + data_blob_free(&spnego->negTokenTarg.mechListMIC); + break; + default: + ret = false; + break; + } + ZERO_STRUCTP(spnego); +out: + return ret; +} + +bool spnego_write_mech_types(TALLOC_CTX *mem_ctx, + const char * const *mech_types, + DATA_BLOB *blob) +{ + bool ret = false; + struct asn1_data *asn1 = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH); + + if (asn1 == NULL) { + return false; + } + + /* Write mechTypes */ + if (mech_types && *mech_types) { + int i; + + if (!asn1_push_tag(asn1, ASN1_SEQUENCE(0))) goto err; + for (i = 0; mech_types[i]; i++) { + if (!asn1_write_OID(asn1, mech_types[i])) goto err; + } + if (!asn1_pop_tag(asn1)) goto err; + } + + if (asn1_has_error(asn1)) { + goto err; + } + + if (!asn1_extract_blob(asn1, mem_ctx, blob)) { + goto err; + } + + ret = true; + + err: + + asn1_free(asn1); + + return ret; +} |