diff options
Diffstat (limited to 'source3/libsmb/asn1.c')
| -rw-r--r-- | source3/libsmb/asn1.c | 603 |
1 files changed, 603 insertions, 0 deletions
diff --git a/source3/libsmb/asn1.c b/source3/libsmb/asn1.c new file mode 100644 index 0000000000..aca1c48841 --- /dev/null +++ b/source3/libsmb/asn1.c @@ -0,0 +1,603 @@ +/* + Unix SMB/CIFS implementation. + simple SPNEGO routines + Copyright (C) Andrew Tridgell 2001 + + 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" + +/* free an asn1 structure */ +void asn1_free(ASN1_DATA *data) +{ + struct nesting *nesting = data->nesting; + + while (nesting) { + struct nesting *nnext = nesting->next; + free(nesting); + nesting = nnext; + }; + data->nesting = NULL; + SAFE_FREE(data->data); +} + +/* write to the ASN1 buffer, advancing the buffer pointer */ +bool asn1_write(ASN1_DATA *data, const void *p, int len) +{ + if (data->has_error) return false; + if (data->length < data->ofs+len) { + data->data = SMB_REALLOC_ARRAY(data->data, unsigned char, + data->ofs+len); + if (!data->data) { + data->has_error = true; + return false; + } + data->length = data->ofs+len; + } + memcpy(data->data + data->ofs, p, len); + data->ofs += len; + return true; +} + +/* useful fn for writing a uint8 */ +bool asn1_write_uint8(ASN1_DATA *data, uint8 v) +{ + return asn1_write(data, &v, 1); +} + +/* push a tag onto the asn1 data buffer. Used for nested structures */ +bool asn1_push_tag(ASN1_DATA *data, uint8 tag) +{ + struct nesting *nesting; + + asn1_write_uint8(data, tag); + nesting = SMB_MALLOC_P(struct nesting); + if (!nesting) { + data->has_error = true; + return false; + } + + nesting->start = data->ofs; + nesting->next = data->nesting; + data->nesting = nesting; + return asn1_write_uint8(data, 0xff); +} + +/* pop a tag */ +bool asn1_pop_tag(ASN1_DATA *data) +{ + struct nesting *nesting; + size_t len; + + if (data->has_error) { + return false; + } + + nesting = data->nesting; + + if (!nesting) { + data->has_error = true; + return false; + } + len = data->ofs - (nesting->start+1); + /* yes, this is ugly. We don't know in advance how many bytes the length + of a tag will take, so we assumed 1 byte. If we were wrong then we + need to correct our mistake */ + if (len > 0xFFFF) { + data->data[nesting->start] = 0x83; + if (!asn1_write_uint8(data, 0)) return false; + if (!asn1_write_uint8(data, 0)) return false; + if (!asn1_write_uint8(data, 0)) return false; + memmove(data->data+nesting->start+4, data->data+nesting->start+1, len); + data->data[nesting->start+1] = (len>>16) & 0xFF; + data->data[nesting->start+2] = (len>>8) & 0xFF; + data->data[nesting->start+3] = len&0xff; + } else if (len > 255) { + data->data[nesting->start] = 0x82; + if (!asn1_write_uint8(data, 0)) return false; + if (!asn1_write_uint8(data, 0)) return false; + memmove(data->data+nesting->start+3, data->data+nesting->start+1, len); + data->data[nesting->start+1] = len>>8; + data->data[nesting->start+2] = len&0xff; + } else if (len > 127) { + data->data[nesting->start] = 0x81; + if (!asn1_write_uint8(data, 0)) return false; + memmove(data->data+nesting->start+2, data->data+nesting->start+1, len); + data->data[nesting->start+1] = len; + } else { + data->data[nesting->start] = len; + } + + data->nesting = nesting->next; + free(nesting); + return true; +} + + +/* write an integer */ +bool asn1_write_Integer(ASN1_DATA *data, int i) +{ + if (!asn1_push_tag(data, ASN1_INTEGER)) return false; + do { + asn1_write_uint8(data, i); + i = i >> 8; + } while (i); + return asn1_pop_tag(data); +} + +/* write an object ID to a ASN1 buffer */ +bool asn1_write_OID(ASN1_DATA *data, const char *OID) +{ + unsigned v, v2; + const char *p = (const char *)OID; + char *newp; + + if (!asn1_push_tag(data, ASN1_OID)) + return false; + v = strtol(p, &newp, 10); + p = newp; + v2 = strtol(p, &newp, 10); + p = newp; + if (!asn1_write_uint8(data, 40*v + v2)) + return false; + + while (*p) { + v = strtol(p, &newp, 10); + p = newp; + if (v >= (1<<28)) asn1_write_uint8(data, 0x80 | ((v>>28)&0xff)); + if (v >= (1<<21)) asn1_write_uint8(data, 0x80 | ((v>>21)&0xff)); + if (v >= (1<<14)) asn1_write_uint8(data, 0x80 | ((v>>14)&0xff)); + if (v >= (1<<7)) asn1_write_uint8(data, 0x80 | ((v>>7)&0xff)); + if (!asn1_write_uint8(data, v&0x7f)) + return false; + } + return asn1_pop_tag(data); +} + +/* write an octet string */ +bool asn1_write_OctetString(ASN1_DATA *data, const void *p, size_t length) +{ + asn1_push_tag(data, ASN1_OCTET_STRING); + asn1_write(data, p, length); + asn1_pop_tag(data); + return !data->has_error; +} + +/* write a general string */ +bool asn1_write_GeneralString(ASN1_DATA *data, const char *s) +{ + asn1_push_tag(data, ASN1_GENERAL_STRING); + asn1_write(data, s, strlen(s)); + asn1_pop_tag(data); + return !data->has_error; +} + +/* write a BOOLEAN */ +bool asn1_write_BOOLEAN(ASN1_DATA *data, bool v) +{ + asn1_write_uint8(data, ASN1_BOOLEAN); + asn1_write_uint8(data, v); + return !data->has_error; +} + +/* write a BOOLEAN - hmm, I suspect this one is the correct one, and the + above boolean is bogus. Need to check */ +bool asn1_write_BOOLEAN2(ASN1_DATA *data, bool v) +{ + asn1_push_tag(data, ASN1_BOOLEAN); + asn1_write_uint8(data, v); + asn1_pop_tag(data); + return !data->has_error; +} + +/* check a BOOLEAN */ +bool asn1_check_BOOLEAN(ASN1_DATA *data, bool v) +{ + uint8 b = 0; + + asn1_read_uint8(data, &b); + if (b != ASN1_BOOLEAN) { + data->has_error = true; + return false; + } + asn1_read_uint8(data, &b); + if (b != v) { + data->has_error = true; + return false; + } + return !data->has_error; +} + + +/* load a ASN1_DATA structure with a lump of data, ready to be parsed */ +bool asn1_load(ASN1_DATA *data, DATA_BLOB blob) +{ + ZERO_STRUCTP(data); + data->data = (unsigned char *)memdup(blob.data, blob.length); + if (!data->data) { + data->has_error = true; + return false; + } + data->length = blob.length; + return true; +} + +/* read from a ASN1 buffer, advancing the buffer pointer */ +bool asn1_read(ASN1_DATA *data, void *p, int len) +{ + if (data->has_error) + return false; + + if (len < 0 || data->ofs + len < data->ofs || data->ofs + len < len) { + data->has_error = true; + return false; + } + + if (data->ofs + len > data->length) { + data->has_error = true; + return false; + } + memcpy(p, data->data + data->ofs, len); + data->ofs += len; + return true; +} + +/* read a uint8 from a ASN1 buffer */ +bool asn1_read_uint8(ASN1_DATA *data, uint8 *v) +{ + return asn1_read(data, v, 1); +} + +/* + * Check thta the value of the ASN1 buffer at the current offset equals tag. + */ +bool asn1_check_tag(ASN1_DATA *data, uint8 tag) +{ + if (data->has_error || data->ofs >= data->length || data->ofs < 0) { + data->has_error = true; + return false; + } + + return (tag == data->data[data->ofs]); +} + +/* start reading a nested asn1 structure */ +bool asn1_start_tag(ASN1_DATA *data, uint8 tag) +{ + uint8 b; + struct nesting *nesting; + + if (!asn1_read_uint8(data, &b)) + return false; + + if (b != tag) { + data->has_error = true; + return false; + } + nesting = SMB_MALLOC_P(struct nesting); + if (!nesting) { + data->has_error = true; + return false; + } + + if (!asn1_read_uint8(data, &b)) { + SAFE_FREE(nesting); + return false; + } + + if (b & 0x80) { + int n = b & 0x7f; + if (!asn1_read_uint8(data, &b)) { + SAFE_FREE(nesting); + return false; + } + nesting->taglen = b; + while (n > 1) { + if (!asn1_read_uint8(data, &b)) { + SAFE_FREE(nesting); + return false; + } + nesting->taglen = (nesting->taglen << 8) | b; + n--; + } + } else { + nesting->taglen = b; + } + nesting->start = data->ofs; + nesting->next = data->nesting; + data->nesting = nesting; + return !data->has_error; +} + + +/* stop reading a tag */ +bool asn1_end_tag(ASN1_DATA *data) +{ + struct nesting *nesting; + + /* make sure we read it all */ + if (asn1_tag_remaining(data) != 0) { + data->has_error = true; + return false; + } + + nesting = data->nesting; + + if (!nesting) { + data->has_error = true; + return false; + } + + data->nesting = nesting->next; + free(nesting); + return true; +} + +/* work out how many bytes are left in this nested tag */ +int asn1_tag_remaining(ASN1_DATA *data) +{ + if (data->has_error) + return 0; + + if (!data->nesting) { + data->has_error = true; + return -1; + } + return data->nesting->taglen - (data->ofs - data->nesting->start); +} + +/* read an object ID from a ASN1 buffer */ +bool asn1_read_OID(ASN1_DATA *data, char **OID) +{ + uint8 b = 0; + char *oid_str = NULL; + + *OID = NULL; + + if (!asn1_start_tag(data, ASN1_OID)) { + return false; + } + asn1_read_uint8(data, &b); + + oid_str = talloc_asprintf(NULL, + "%u", + b/40); + if (!oid_str) { + data->has_error = true; + goto out; + } + oid_str = talloc_asprintf_append(oid_str, + " %u", + b%40); + if (!oid_str) { + data->has_error = true; + goto out; + } + + while (asn1_tag_remaining(data) > 0) { + unsigned v = 0; + do { + asn1_read_uint8(data, &b); + v = (v<<7) | (b&0x7f); + } while (!data->has_error && b & 0x80); + oid_str = talloc_asprintf_append(oid_str, + " %u", + v); + if (!oid_str) { + data->has_error = true; + goto out; + } + } + + out: + + asn1_end_tag(data); + + if (!data->has_error) { + *OID = SMB_STRDUP(oid_str); + } + + TALLOC_FREE(oid_str); + + return !data->has_error; +} + +/* check that the next object ID is correct */ +bool asn1_check_OID(ASN1_DATA *data, const char *OID) +{ + char *id; + + if (!asn1_read_OID(data, &id)) { + return false; + } + + if (strcmp(id, OID) != 0) { + data->has_error = true; + free(id); + return false; + } + free(id); + return true; +} + +/* read a GeneralString from a ASN1 buffer */ +bool asn1_read_GeneralString(ASN1_DATA *data, char **s) +{ + int len; + char *str; + + *s = NULL; + + if (!asn1_start_tag(data, ASN1_GENERAL_STRING)) { + return false; + } + len = asn1_tag_remaining(data); + if (len < 0) { + data->has_error = true; + return false; + } + str = SMB_MALLOC_ARRAY(char, len+1); + if (!str) { + data->has_error = true; + return false; + } + asn1_read(data, str, len); + str[len] = 0; + asn1_end_tag(data); + + if (!data->has_error) { + *s = str; + } + return !data->has_error; +} + +/* read a octet string blob */ +bool asn1_read_OctetString(ASN1_DATA *data, DATA_BLOB *blob) +{ + int len; + ZERO_STRUCTP(blob); + if (!asn1_start_tag(data, ASN1_OCTET_STRING)) return false; + len = asn1_tag_remaining(data); + if (len < 0) { + data->has_error = true; + return false; + } + *blob = data_blob(NULL, len); + asn1_read(data, blob->data, len); + asn1_end_tag(data); + return !data->has_error; +} + +/* read an interger */ +bool asn1_read_Integer(ASN1_DATA *data, int *i) +{ + uint8 b; + *i = 0; + + if (!asn1_start_tag(data, ASN1_INTEGER)) return false; + while (asn1_tag_remaining(data)>0) { + asn1_read_uint8(data, &b); + *i = (*i << 8) + b; + } + return asn1_end_tag(data); + +} + +/* check a enumarted value is correct */ +bool asn1_check_enumerated(ASN1_DATA *data, int v) +{ + uint8 b; + if (!asn1_start_tag(data, ASN1_ENUMERATED)) return false; + asn1_read_uint8(data, &b); + asn1_end_tag(data); + + if (v != b) + data->has_error = false; + + return !data->has_error; +} + +/* write an enumarted value to the stream */ +bool asn1_write_enumerated(ASN1_DATA *data, uint8 v) +{ + if (!asn1_push_tag(data, ASN1_ENUMERATED)) return false; + asn1_write_uint8(data, v); + asn1_pop_tag(data); + return !data->has_error; +} + +bool ber_write_OID_String(DATA_BLOB *blob, const char *OID) +{ + uint_t v, v2; + const char *p = (const char *)OID; + char *newp; + int i; + + v = strtoul(p, &newp, 10); + if (newp[0] != '.') return false; + p = newp + 1; + + v2 = strtoul(p, &newp, 10); + if (newp[0] != '.') return false; + p = newp + 1; + + /*the ber representation can't use more space then the string one */ + *blob = data_blob(NULL, strlen(OID)); + if (!blob->data) return false; + + blob->data[0] = 40*v + v2; + + i = 1; + while (*p) { + v = strtoul(p, &newp, 10); + if (newp[0] == '.') { + p = newp + 1; + } else if (newp[0] == '\0') { + p = newp; + } else { + data_blob_free(blob); + return false; + } + if (v >= (1<<28)) blob->data[i++] = (0x80 | ((v>>28)&0x7f)); + if (v >= (1<<21)) blob->data[i++] = (0x80 | ((v>>21)&0x7f)); + if (v >= (1<<14)) blob->data[i++] = (0x80 | ((v>>14)&0x7f)); + if (v >= (1<<7)) blob->data[i++] = (0x80 | ((v>>7)&0x7f)); + blob->data[i++] = (v&0x7f); + } + + blob->length = i; + + return true; +} + +/* read an object ID from a data blob */ +bool ber_read_OID_String(TALLOC_CTX *mem_ctx, DATA_BLOB blob, const char **OID) +{ + int i; + uint8_t *b; + uint_t v; + char *tmp_oid = NULL; + + if (blob.length < 2) return false; + + b = blob.data; + + tmp_oid = talloc_asprintf(mem_ctx, "%u", b[0]/40); + if (!tmp_oid) goto nomem; + tmp_oid = talloc_asprintf_append_buffer(tmp_oid, ".%u", b[0]%40); + if (!tmp_oid) goto nomem; + + for(i = 1, v = 0; i < blob.length; i++) { + v = (v<<7) | (b[i]&0x7f); + if ( ! (b[i] & 0x80)) { + tmp_oid = talloc_asprintf_append_buffer(tmp_oid, ".%u", v); + v = 0; + } + if (!tmp_oid) goto nomem; + } + + if (v != 0) { + talloc_free(tmp_oid); + return false; + } + + *OID = tmp_oid; + return true; + +nomem: + return false; +} + + |