diff options
Diffstat (limited to 'fs/cifs/asn1.c')
| -rw-r--r-- | fs/cifs/asn1.c | 623 |
1 files changed, 37 insertions, 586 deletions
diff --git a/fs/cifs/asn1.c b/fs/cifs/asn1.c index 3150c19cdc2f..b5724ef9f182 100644 --- a/fs/cifs/asn1.c +++ b/fs/cifs/asn1.c @@ -1,612 +1,63 @@ // SPDX-License-Identifier: GPL-2.0-or-later -/* - * The ASB.1/BER parsing code is derived from ip_nat_snmp_basic.c which was in - * turn derived from the gxsnmp package by Gregory McLean & Jochen Friedrich - * - * Copyright (c) 2000 RP Internet (www.rpi.net.au). - */ #include <linux/module.h> -#include <linux/types.h> #include <linux/kernel.h> -#include <linux/mm.h> -#include <linux/slab.h> -#include "cifspdu.h" +#include <linux/oid_registry.h> #include "cifsglob.h" #include "cifs_debug.h" #include "cifsproto.h" +#include "cifs_spnego_negtokeninit.asn1.h" -/***************************************************************************** - * - * Basic ASN.1 decoding routines (gxsnmp author Dirk Wisse) - * - *****************************************************************************/ - -/* Class */ -#define ASN1_UNI 0 /* Universal */ -#define ASN1_APL 1 /* Application */ -#define ASN1_CTX 2 /* Context */ -#define ASN1_PRV 3 /* Private */ - -/* Tag */ -#define ASN1_EOC 0 /* End Of Contents or N/A */ -#define ASN1_BOL 1 /* Boolean */ -#define ASN1_INT 2 /* Integer */ -#define ASN1_BTS 3 /* Bit String */ -#define ASN1_OTS 4 /* Octet String */ -#define ASN1_NUL 5 /* Null */ -#define ASN1_OJI 6 /* Object Identifier */ -#define ASN1_OJD 7 /* Object Description */ -#define ASN1_EXT 8 /* External */ -#define ASN1_ENUM 10 /* Enumerated */ -#define ASN1_SEQ 16 /* Sequence */ -#define ASN1_SET 17 /* Set */ -#define ASN1_NUMSTR 18 /* Numerical String */ -#define ASN1_PRNSTR 19 /* Printable String */ -#define ASN1_TEXSTR 20 /* Teletext String */ -#define ASN1_VIDSTR 21 /* Video String */ -#define ASN1_IA5STR 22 /* IA5 String */ -#define ASN1_UNITIM 23 /* Universal Time */ -#define ASN1_GENTIM 24 /* General Time */ -#define ASN1_GRASTR 25 /* Graphical String */ -#define ASN1_VISSTR 26 /* Visible String */ -#define ASN1_GENSTR 27 /* General String */ - -/* Primitive / Constructed methods*/ -#define ASN1_PRI 0 /* Primitive */ -#define ASN1_CON 1 /* Constructed */ - -/* - * Error codes. - */ -#define ASN1_ERR_NOERROR 0 -#define ASN1_ERR_DEC_EMPTY 2 -#define ASN1_ERR_DEC_EOC_MISMATCH 3 -#define ASN1_ERR_DEC_LENGTH_MISMATCH 4 -#define ASN1_ERR_DEC_BADVALUE 5 - -#define SPNEGO_OID_LEN 7 -#define NTLMSSP_OID_LEN 10 -#define KRB5_OID_LEN 7 -#define KRB5U2U_OID_LEN 8 -#define MSKRB5_OID_LEN 7 -static unsigned long SPNEGO_OID[7] = { 1, 3, 6, 1, 5, 5, 2 }; -static unsigned long NTLMSSP_OID[10] = { 1, 3, 6, 1, 4, 1, 311, 2, 2, 10 }; -static unsigned long KRB5_OID[7] = { 1, 2, 840, 113554, 1, 2, 2 }; -static unsigned long KRB5U2U_OID[8] = { 1, 2, 840, 113554, 1, 2, 2, 3 }; -static unsigned long MSKRB5_OID[7] = { 1, 2, 840, 48018, 1, 2, 2 }; - -/* - * ASN.1 context. - */ -struct asn1_ctx { - int error; /* Error condition */ - unsigned char *pointer; /* Octet just to be decoded */ - unsigned char *begin; /* First octet */ - unsigned char *end; /* Octet after last octet */ -}; - -/* - * Octet string (not null terminated) - */ -struct asn1_octstr { - unsigned char *data; - unsigned int len; -}; - -static void -asn1_open(struct asn1_ctx *ctx, unsigned char *buf, unsigned int len) -{ - ctx->begin = buf; - ctx->end = buf + len; - ctx->pointer = buf; - ctx->error = ASN1_ERR_NOERROR; -} - -static unsigned char -asn1_octet_decode(struct asn1_ctx *ctx, unsigned char *ch) -{ - if (ctx->pointer >= ctx->end) { - ctx->error = ASN1_ERR_DEC_EMPTY; - return 0; - } - *ch = *(ctx->pointer)++; - return 1; -} - -#if 0 /* will be needed later by spnego decoding/encoding of ntlmssp */ -static unsigned char -asn1_enum_decode(struct asn1_ctx *ctx, __le32 *val) -{ - unsigned char ch; - - if (ctx->pointer >= ctx->end) { - ctx->error = ASN1_ERR_DEC_EMPTY; - return 0; - } - - ch = *(ctx->pointer)++; /* ch has 0xa, ptr points to length octet */ - if ((ch) == ASN1_ENUM) /* if ch value is ENUM, 0xa */ - *val = *(++(ctx->pointer)); /* value has enum value */ - else - return 0; - - ctx->pointer++; - return 1; -} -#endif - -static unsigned char -asn1_tag_decode(struct asn1_ctx *ctx, unsigned int *tag) -{ - unsigned char ch; - - *tag = 0; - - do { - if (!asn1_octet_decode(ctx, &ch)) - return 0; - *tag <<= 7; - *tag |= ch & 0x7F; - } while ((ch & 0x80) == 0x80); - return 1; -} - -static unsigned char -asn1_id_decode(struct asn1_ctx *ctx, - unsigned int *cls, unsigned int *con, unsigned int *tag) -{ - unsigned char ch; - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *cls = (ch & 0xC0) >> 6; - *con = (ch & 0x20) >> 5; - *tag = (ch & 0x1F); - - if (*tag == 0x1F) { - if (!asn1_tag_decode(ctx, tag)) - return 0; - } - return 1; -} - -static unsigned char -asn1_length_decode(struct asn1_ctx *ctx, unsigned int *def, unsigned int *len) -{ - unsigned char ch, cnt; - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - if (ch == 0x80) - *def = 0; - else { - *def = 1; - - if (ch < 0x80) - *len = ch; - else { - cnt = (unsigned char) (ch & 0x7F); - *len = 0; - - while (cnt > 0) { - if (!asn1_octet_decode(ctx, &ch)) - return 0; - *len <<= 8; - *len |= ch; - cnt--; - } - } - } - - /* don't trust len bigger than ctx buffer */ - if (*len > ctx->end - ctx->pointer) - return 0; - - return 1; -} - -static unsigned char -asn1_header_decode(struct asn1_ctx *ctx, - unsigned char **eoc, - unsigned int *cls, unsigned int *con, unsigned int *tag) -{ - unsigned int def = 0; - unsigned int len = 0; - - if (!asn1_id_decode(ctx, cls, con, tag)) - return 0; - - if (!asn1_length_decode(ctx, &def, &len)) - return 0; - - /* primitive shall be definite, indefinite shall be constructed */ - if (*con == ASN1_PRI && !def) - return 0; - - if (def) - *eoc = ctx->pointer + len; - else - *eoc = NULL; - return 1; -} - -static unsigned char -asn1_eoc_decode(struct asn1_ctx *ctx, unsigned char *eoc) +int +decode_negTokenInit(unsigned char *security_blob, int length, + struct TCP_Server_Info *server) { - unsigned char ch; - - if (eoc == NULL) { - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - if (ch != 0x00) { - ctx->error = ASN1_ERR_DEC_EOC_MISMATCH; - return 0; - } - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - if (ch != 0x00) { - ctx->error = ASN1_ERR_DEC_EOC_MISMATCH; - return 0; - } - return 1; - } else { - if (ctx->pointer != eoc) { - ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH; - return 0; - } + if (asn1_ber_decoder(&cifs_spnego_negtokeninit_decoder, server, + security_blob, length) == 0) return 1; - } -} - -/* static unsigned char asn1_null_decode(struct asn1_ctx *ctx, - unsigned char *eoc) -{ - ctx->pointer = eoc; - return 1; -} - -static unsigned char asn1_long_decode(struct asn1_ctx *ctx, - unsigned char *eoc, long *integer) -{ - unsigned char ch; - unsigned int len; - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *integer = (signed char) ch; - len = 1; - - while (ctx->pointer < eoc) { - if (++len > sizeof(long)) { - ctx->error = ASN1_ERR_DEC_BADVALUE; - return 0; - } - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *integer <<= 8; - *integer |= ch; - } - return 1; -} - -static unsigned char asn1_uint_decode(struct asn1_ctx *ctx, - unsigned char *eoc, - unsigned int *integer) -{ - unsigned char ch; - unsigned int len; - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *integer = ch; - if (ch == 0) - len = 0; else - len = 1; - - while (ctx->pointer < eoc) { - if (++len > sizeof(unsigned int)) { - ctx->error = ASN1_ERR_DEC_BADVALUE; - return 0; - } - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *integer <<= 8; - *integer |= ch; - } - return 1; -} - -static unsigned char asn1_ulong_decode(struct asn1_ctx *ctx, - unsigned char *eoc, - unsigned long *integer) -{ - unsigned char ch; - unsigned int len; - - if (!asn1_octet_decode(ctx, &ch)) return 0; - - *integer = ch; - if (ch == 0) - len = 0; - else - len = 1; - - while (ctx->pointer < eoc) { - if (++len > sizeof(unsigned long)) { - ctx->error = ASN1_ERR_DEC_BADVALUE; - return 0; - } - - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *integer <<= 8; - *integer |= ch; - } - return 1; } -static unsigned char -asn1_octets_decode(struct asn1_ctx *ctx, - unsigned char *eoc, - unsigned char **octets, unsigned int *len) +int cifs_gssapi_this_mech(void *context, size_t hdrlen, + unsigned char tag, const void *value, size_t vlen) { - unsigned char *ptr; - - *len = 0; - - *octets = kmalloc(eoc - ctx->pointer, GFP_ATOMIC); - if (*octets == NULL) { - return 0; - } - - ptr = *octets; - while (ctx->pointer < eoc) { - if (!asn1_octet_decode(ctx, (unsigned char *) ptr++)) { - kfree(*octets); - *octets = NULL; - return 0; - } - (*len)++; - } - return 1; -} */ - -static unsigned char -asn1_subid_decode(struct asn1_ctx *ctx, unsigned long *subid) -{ - unsigned char ch; - - *subid = 0; - - do { - if (!asn1_octet_decode(ctx, &ch)) - return 0; - - *subid <<= 7; - *subid |= ch & 0x7F; - } while ((ch & 0x80) == 0x80); - return 1; -} - -static int -asn1_oid_decode(struct asn1_ctx *ctx, - unsigned char *eoc, unsigned long **oid, unsigned int *len) -{ - unsigned long subid; - unsigned int size; - unsigned long *optr; - - size = eoc - ctx->pointer + 1; - - /* first subid actually encodes first two subids */ - if (size < 2 || size > UINT_MAX/sizeof(unsigned long)) - return 0; - - *oid = kmalloc_array(size, sizeof(unsigned long), GFP_ATOMIC); - if (*oid == NULL) - return 0; - - optr = *oid; - - if (!asn1_subid_decode(ctx, &subid)) { - kfree(*oid); - *oid = NULL; - return 0; - } - - if (subid < 40) { - optr[0] = 0; - optr[1] = subid; - } else if (subid < 80) { - optr[0] = 1; - optr[1] = subid - 40; - } else { - optr[0] = 2; - optr[1] = subid - 80; - } - - *len = 2; - optr += 2; + enum OID oid; - while (ctx->pointer < eoc) { - if (++(*len) > size) { - ctx->error = ASN1_ERR_DEC_BADVALUE; - kfree(*oid); - *oid = NULL; - return 0; - } + oid = look_up_OID(value, vlen); + if (oid != OID_spnego) { + char buf[50]; - if (!asn1_subid_decode(ctx, optr++)) { - kfree(*oid); - *oid = NULL; - return 0; - } + sprint_oid(value, vlen, buf, sizeof(buf)); + cifs_dbg(FYI, "Error decoding negTokenInit header: unexpected OID %s\n", + buf); + return -EBADMSG; } - return 1; + return 0; } -static int -compare_oid(unsigned long *oid1, unsigned int oid1len, - unsigned long *oid2, unsigned int oid2len) +int cifs_neg_token_init_mech_type(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) { - unsigned int i; + struct TCP_Server_Info *server = context; + enum OID oid; - if (oid1len != oid2len) - return 0; + oid = look_up_OID(value, vlen); + if (oid == OID_mskrb5) + server->sec_mskerberos = true; + else if (oid == OID_krb5u2u) + server->sec_kerberosu2u = true; + else if (oid == OID_krb5) + server->sec_kerberos = true; + else if (oid == OID_ntlmssp) + server->sec_ntlmssp = true; else { - for (i = 0; i < oid1len; i++) { - if (oid1[i] != oid2[i]) - return 0; - } - return 1; - } -} - - /* BB check for endian conversion issues here */ - -int -decode_negTokenInit(unsigned char *security_blob, int length, - struct TCP_Server_Info *server) -{ - struct asn1_ctx ctx; - unsigned char *end; - unsigned char *sequence_end; - unsigned long *oid = NULL; - unsigned int cls, con, tag, oidlen, rc; - - /* cifs_dump_mem(" Received SecBlob ", security_blob, length); */ - - asn1_open(&ctx, security_blob, length); + char buf[50]; - /* GSSAPI header */ - if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { - cifs_dbg(FYI, "Error decoding negTokenInit header\n"); - return 0; - } else if ((cls != ASN1_APL) || (con != ASN1_CON) - || (tag != ASN1_EOC)) { - cifs_dbg(FYI, "cls = %d con = %d tag = %d\n", cls, con, tag); - return 0; + sprint_oid(value, vlen, buf, sizeof(buf)); + cifs_dbg(FYI, "Decoding negTokenInit: unsupported OID %s\n", + buf); } - - /* Check for SPNEGO OID -- remember to free obj->oid */ - rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag); - if (rc) { - if ((tag == ASN1_OJI) && (con == ASN1_PRI) && - (cls == ASN1_UNI)) { - rc = asn1_oid_decode(&ctx, end, &oid, &oidlen); - if (rc) { - rc = compare_oid(oid, oidlen, SPNEGO_OID, - SPNEGO_OID_LEN); - kfree(oid); - } - } else - rc = 0; - } - - /* SPNEGO OID not present or garbled -- bail out */ - if (!rc) { - cifs_dbg(FYI, "Error decoding negTokenInit header\n"); - return 0; - } - - /* SPNEGO */ - if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { - cifs_dbg(FYI, "Error decoding negTokenInit\n"); - return 0; - } else if ((cls != ASN1_CTX) || (con != ASN1_CON) - || (tag != ASN1_EOC)) { - cifs_dbg(FYI, "cls = %d con = %d tag = %d end = %p exit 0\n", - cls, con, tag, end); - return 0; - } - - /* negTokenInit */ - if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { - cifs_dbg(FYI, "Error decoding negTokenInit\n"); - return 0; - } else if ((cls != ASN1_UNI) || (con != ASN1_CON) - || (tag != ASN1_SEQ)) { - cifs_dbg(FYI, "cls = %d con = %d tag = %d end = %p exit 1\n", - cls, con, tag, end); - return 0; - } - - /* sequence */ - if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { - cifs_dbg(FYI, "Error decoding 2nd part of negTokenInit\n"); - return 0; - } else if ((cls != ASN1_CTX) || (con != ASN1_CON) - || (tag != ASN1_EOC)) { - cifs_dbg(FYI, "cls = %d con = %d tag = %d end = %p exit 0\n", - cls, con, tag, end); - return 0; - } - - /* sequence of */ - if (asn1_header_decode - (&ctx, &sequence_end, &cls, &con, &tag) == 0) { - cifs_dbg(FYI, "Error decoding 2nd part of negTokenInit\n"); - return 0; - } else if ((cls != ASN1_UNI) || (con != ASN1_CON) - || (tag != ASN1_SEQ)) { - cifs_dbg(FYI, "cls = %d con = %d tag = %d sequence_end = %p exit 1\n", - cls, con, tag, sequence_end); - return 0; - } - - /* list of security mechanisms */ - while (!asn1_eoc_decode(&ctx, sequence_end)) { - rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag); - if (!rc) { - cifs_dbg(FYI, "Error decoding negTokenInit hdr exit2\n"); - return 0; - } - if ((tag == ASN1_OJI) && (con == ASN1_PRI)) { - if (asn1_oid_decode(&ctx, end, &oid, &oidlen)) { - - cifs_dbg(FYI, "OID len = %d oid = 0x%lx 0x%lx 0x%lx 0x%lx\n", - oidlen, *oid, *(oid + 1), *(oid + 2), - *(oid + 3)); - - if (compare_oid(oid, oidlen, MSKRB5_OID, - MSKRB5_OID_LEN)) - server->sec_mskerberos = true; - else if (compare_oid(oid, oidlen, KRB5U2U_OID, - KRB5U2U_OID_LEN)) - server->sec_kerberosu2u = true; - else if (compare_oid(oid, oidlen, KRB5_OID, - KRB5_OID_LEN)) - server->sec_kerberos = true; - else if (compare_oid(oid, oidlen, NTLMSSP_OID, - NTLMSSP_OID_LEN)) - server->sec_ntlmssp = true; - - kfree(oid); - } - } else { - cifs_dbg(FYI, "Should be an oid what is going on?\n"); - } - } - - /* - * We currently ignore anything at the end of the SPNEGO blob after - * the mechTypes have been parsed, since none of that info is - * used at the moment. - */ - return 1; + return 0; } |