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author | Kim Kibum <kb0929.kim@samsung.com> | 2012-04-29 16:59:19 +0900 |
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committer | Kim Kibum <kb0929.kim@samsung.com> | 2012-04-29 16:59:19 +0900 |
commit | c1775d1a93a77a57380a4ce87ac3a8f807c944b2 (patch) | |
tree | e1f233f2af38ee247a677082198dd3a69a12a5a1 /fs/cifs/asn1.c | |
parent | 2c2dcd5ffef2e97176e6a55e45512177e55e6fb9 (diff) | |
download | linux-2.6.36-c1775d1a93a77a57380a4ce87ac3a8f807c944b2.tar.gz linux-2.6.36-c1775d1a93a77a57380a4ce87ac3a8f807c944b2.tar.bz2 linux-2.6.36-c1775d1a93a77a57380a4ce87ac3a8f807c944b2.zip |
Diffstat (limited to 'fs/cifs/asn1.c')
-rw-r--r-- | fs/cifs/asn1.c | 666 |
1 files changed, 666 insertions, 0 deletions
diff --git a/fs/cifs/asn1.c b/fs/cifs/asn1.c new file mode 100644 index 00000000..cfd1ce34 --- /dev/null +++ b/fs/cifs/asn1.c @@ -0,0 +1,666 @@ +/* + * 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). + * + * 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 2 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include "cifspdu.h" +#include "cifsglob.h" +#include "cifs_debug.h" +#include "cifsproto.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) +{ + 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; + } + 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) +{ + 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(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; + + while (ctx->pointer < eoc) { + if (++(*len) > size) { + ctx->error = ASN1_ERR_DEC_BADVALUE; + kfree(*oid); + *oid = NULL; + return 0; + } + + if (!asn1_subid_decode(ctx, optr++)) { + kfree(*oid); + *oid = NULL; + return 0; + } + } + return 1; +} + +static int +compare_oid(unsigned long *oid1, unsigned int oid1len, + unsigned long *oid2, unsigned int oid2len) +{ + unsigned int i; + + if (oid1len != oid2len) + return 0; + 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); + + /* GSSAPI header */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding negTokenInit header"); + return 0; + } else if ((cls != ASN1_APL) || (con != ASN1_CON) + || (tag != ASN1_EOC)) { + cFYI(1, "cls = %d con = %d tag = %d", cls, con, tag); + return 0; + } + + /* 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) { + cFYI(1, "Error decoding negTokenInit header"); + return 0; + } + + /* SPNEGO */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding negTokenInit"); + return 0; + } else if ((cls != ASN1_CTX) || (con != ASN1_CON) + || (tag != ASN1_EOC)) { + cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 0", + cls, con, tag, end, *end); + return 0; + } + + /* negTokenInit */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding negTokenInit"); + return 0; + } else if ((cls != ASN1_UNI) || (con != ASN1_CON) + || (tag != ASN1_SEQ)) { + cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 1", + cls, con, tag, end, *end); + return 0; + } + + /* sequence */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding 2nd part of negTokenInit"); + return 0; + } else if ((cls != ASN1_CTX) || (con != ASN1_CON) + || (tag != ASN1_EOC)) { + cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 0", + cls, con, tag, end, *end); + return 0; + } + + /* sequence of */ + if (asn1_header_decode + (&ctx, &sequence_end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding 2nd part of negTokenInit"); + return 0; + } else if ((cls != ASN1_UNI) || (con != ASN1_CON) + || (tag != ASN1_SEQ)) { + cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 1", + cls, con, tag, end, *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) { + cFYI(1, "Error decoding negTokenInit hdr exit2"); + return 0; + } + if ((tag == ASN1_OJI) && (con == ASN1_PRI)) { + if (asn1_oid_decode(&ctx, end, &oid, &oidlen)) { + + cFYI(1, "OID len = %d oid = 0x%lx 0x%lx " + "0x%lx 0x%lx", 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 { + cFYI(1, "Should be an oid what is going on?"); + } + } + + /* mechlistMIC */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + /* Check if we have reached the end of the blob, but with + no mechListMic (e.g. NTLMSSP instead of KRB5) */ + if (ctx.error == ASN1_ERR_DEC_EMPTY) + goto decode_negtoken_exit; + cFYI(1, "Error decoding last part negTokenInit exit3"); + return 0; + } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) { + /* tag = 3 indicating mechListMIC */ + cFYI(1, "Exit 4 cls = %d con = %d tag = %d end = %p (%d)", + cls, con, tag, end, *end); + return 0; + } + + /* sequence */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding last part negTokenInit exit5"); + return 0; + } else if ((cls != ASN1_UNI) || (con != ASN1_CON) + || (tag != ASN1_SEQ)) { + cFYI(1, "cls = %d con = %d tag = %d end = %p (%d)", + cls, con, tag, end, *end); + } + + /* sequence of */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding last part negTokenInit exit 7"); + return 0; + } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) { + cFYI(1, "Exit 8 cls = %d con = %d tag = %d end = %p (%d)", + cls, con, tag, end, *end); + return 0; + } + + /* general string */ + if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) { + cFYI(1, "Error decoding last part negTokenInit exit9"); + return 0; + } else if ((cls != ASN1_UNI) || (con != ASN1_PRI) + || (tag != ASN1_GENSTR)) { + cFYI(1, "Exit10 cls = %d con = %d tag = %d end = %p (%d)", + cls, con, tag, end, *end); + return 0; + } + cFYI(1, "Need to call asn1_octets_decode() function for %s", + ctx.pointer); /* is this UTF-8 or ASCII? */ +decode_negtoken_exit: + return 1; +} |