On Sat, Oct 12, 2019 at 02:29:49PM +0200, Heinrich Schuchardt wrote:
On 10/11/19 9:41 AM, AKASHI Takahiro wrote:
Imported from linux kernel v5.3.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org
lib/Kconfig | 6 + lib/Makefile | 1 + lib/asn1_decoder.c | 527 +++++++++++++++++++++++++++++++++++++++++++++
Except for adjustments of include files lib/asn1_decoder.c is a verbatime copy of the Linux kernel file. OK.
3 files changed, 534 insertions(+) create mode 100644 lib/asn1_decoder.c
diff --git a/lib/Kconfig b/lib/Kconfig index 3da45a5ec322..26c94f49ecd2 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -521,6 +521,12 @@ config SMBIOS_PRODUCT_NAME
endmenu
+config ASN1
- bool
- select BUILD_ASN1
BUILD_ASN1 does not really fit into cmd/Kconfig.
I just follows the way of BUILD_BIN2C, but
Should we move it here?
yeah, bin2c is only used under cmd and so moving BUILD_ASN1 to lib/ is fine to me.
Why do we need two separate flags ASN1 and BUILD_ASN1?
My intension here is that CONFIG_ASN1 is for asn1_decoder.o and CONFIG_BUILD_ASN1 is for asn1 compiler. (lib/Makefile is wrong in this sense.) I believe that having different config's here makes sense as those two targets are closely related but different objects.
So I will change their names to clarify this.
-Takahiro Akashi
Best regards
Heinrich
- help
Enable asn1 decoder library.source lib/efi/Kconfig source lib/efi_loader/Kconfig source lib/optee/Kconfig diff --git a/lib/Makefile b/lib/Makefile index 2fffd68f943c..eb3a675fb8c2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_OF_LIVE) += of_live.o obj-$(CONFIG_CMD_DHRYSTONE) += dhry/ obj-$(CONFIG_ARCH_AT91) += at91/ obj-$(CONFIG_OPTEE) += optee/ +obj-$(CONFIG_BUILD_ASN1) += asn1_decoder.o
obj-$(CONFIG_AES) += aes.o
diff --git a/lib/asn1_decoder.c b/lib/asn1_decoder.c new file mode 100644 index 000000000000..db222625dd0f --- /dev/null +++ b/lib/asn1_decoder.c @@ -0,0 +1,527 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Decoder for ASN.1 BER/DER/CER encoded bytestream
- Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
- Written by David Howells (dhowells@redhat.com)
- */
+#ifdef __UBOOT__ +#include <linux/compat.h> +#else +#include <linux/export.h> +#endif +#include <linux/kernel.h> +#include <linux/errno.h> +#ifndef __UBOOT__ +#include <linux/module.h> +#endif +#include <linux/asn1_decoder.h> +#include <linux/asn1_ber_bytecode.h>
+static const unsigned char asn1_op_lengths[ASN1_OP__NR] = {
- /* OPC TAG JMP ACT */
- [ASN1_OP_MATCH] = 1 + 1,
- [ASN1_OP_MATCH_OR_SKIP] = 1 + 1,
- [ASN1_OP_MATCH_ACT] = 1 + 1 + 1,
- [ASN1_OP_MATCH_ACT_OR_SKIP] = 1 + 1 + 1,
- [ASN1_OP_MATCH_JUMP] = 1 + 1 + 1,
- [ASN1_OP_MATCH_JUMP_OR_SKIP] = 1 + 1 + 1,
- [ASN1_OP_MATCH_ANY] = 1,
- [ASN1_OP_MATCH_ANY_OR_SKIP] = 1,
- [ASN1_OP_MATCH_ANY_ACT] = 1 + 1,
- [ASN1_OP_MATCH_ANY_ACT_OR_SKIP] = 1 + 1,
- [ASN1_OP_COND_MATCH_OR_SKIP] = 1 + 1,
- [ASN1_OP_COND_MATCH_ACT_OR_SKIP] = 1 + 1 + 1,
- [ASN1_OP_COND_MATCH_JUMP_OR_SKIP] = 1 + 1 + 1,
- [ASN1_OP_COND_MATCH_ANY] = 1,
- [ASN1_OP_COND_MATCH_ANY_OR_SKIP] = 1,
- [ASN1_OP_COND_MATCH_ANY_ACT] = 1 + 1,
- [ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP] = 1 + 1,
- [ASN1_OP_COND_FAIL] = 1,
- [ASN1_OP_COMPLETE] = 1,
- [ASN1_OP_ACT] = 1 + 1,
- [ASN1_OP_MAYBE_ACT] = 1 + 1,
- [ASN1_OP_RETURN] = 1,
- [ASN1_OP_END_SEQ] = 1,
- [ASN1_OP_END_SEQ_OF] = 1 + 1,
- [ASN1_OP_END_SET] = 1,
- [ASN1_OP_END_SET_OF] = 1 + 1,
- [ASN1_OP_END_SEQ_ACT] = 1 + 1,
- [ASN1_OP_END_SEQ_OF_ACT] = 1 + 1 + 1,
- [ASN1_OP_END_SET_ACT] = 1 + 1,
- [ASN1_OP_END_SET_OF_ACT] = 1 + 1 + 1,
+};
+/*
- Find the length of an indefinite length object
- @data: The data buffer
- @datalen: The end of the innermost containing element in the buffer
- @_dp: The data parse cursor (updated before returning)
- @_len: Where to return the size of the element.
- @_errmsg: Where to return a pointer to an error message on error
- */
+static int asn1_find_indefinite_length(const unsigned char *data, size_t datalen,
size_t *_dp, size_t *_len,const char **_errmsg)+{
- unsigned char tag, tmp;
- size_t dp = *_dp, len, n;
- int indef_level = 1;
+next_tag:
- if (unlikely(datalen - dp < 2)) {
if (datalen == dp)goto missing_eoc;goto data_overrun_error;- }
- /* Extract a tag from the data */
- tag = data[dp++];
- if (tag == ASN1_EOC) {
/* It appears to be an EOC. */if (data[dp++] != 0)goto invalid_eoc;if (--indef_level <= 0) {*_len = dp - *_dp;*_dp = dp;return 0;}goto next_tag;- }
- if (unlikely((tag & 0x1f) == ASN1_LONG_TAG)) {
do {if (unlikely(datalen - dp < 2))goto data_overrun_error;tmp = data[dp++];} while (tmp & 0x80);- }
- /* Extract the length */
- len = data[dp++];
- if (len <= 0x7f)
goto check_length;- if (unlikely(len == ASN1_INDEFINITE_LENGTH)) {
/* Indefinite length */if (unlikely((tag & ASN1_CONS_BIT) == ASN1_PRIM << 5))goto indefinite_len_primitive;indef_level++;goto next_tag;- }
- n = len - 0x80;
- if (unlikely(n > sizeof(len) - 1))
goto length_too_long;- if (unlikely(n > datalen - dp))
goto data_overrun_error;- len = 0;
- for (; n > 0; n--) {
len <<= 8;len |= data[dp++];- }
+check_length:
- if (len > datalen - dp)
goto data_overrun_error;- dp += len;
- goto next_tag;
+length_too_long:
- *_errmsg = "Unsupported length";
- goto error;
+indefinite_len_primitive:
- *_errmsg = "Indefinite len primitive not permitted";
- goto error;
+invalid_eoc:
- *_errmsg = "Invalid length EOC";
- goto error;
+data_overrun_error:
- *_errmsg = "Data overrun error";
- goto error;
+missing_eoc:
- *_errmsg = "Missing EOC in indefinite len cons";
+error:
- *_dp = dp;
- return -1;
+}
+/**
- asn1_ber_decoder - Decoder BER/DER/CER ASN.1 according to pattern
- @decoder: The decoder definition (produced by asn1_compiler)
- @context: The caller's context (to be passed to the action functions)
- @data: The encoded data
- @datalen: The size of the encoded data
- Decode BER/DER/CER encoded ASN.1 data according to a bytecode pattern
- produced by asn1_compiler. Action functions are called on marked tags to
- allow the caller to retrieve significant data.
- LIMITATIONS:
- To keep down the amount of stack used by this function, the following limits
- have been imposed:
- (1) This won't handle datalen > 65535 without increasing the size of the
- cons stack elements and length_too_long checking.
- (2) The stack of constructed types is 10 deep. If the depth of non-leaf
- constructed types exceeds this, the decode will fail.
- (3) The SET type (not the SET OF type) isn't really supported as tracking
- what members of the set have been seen is a pain.
- */
+int asn1_ber_decoder(const struct asn1_decoder *decoder,
void *context,const unsigned char *data,size_t datalen)+{
- const unsigned char *machine = decoder->machine;
- const asn1_action_t *actions = decoder->actions;
- size_t machlen = decoder->machlen;
- enum asn1_opcode op;
- unsigned char tag = 0, csp = 0, jsp = 0, optag = 0, hdr = 0;
- const char *errmsg;
- size_t pc = 0, dp = 0, tdp = 0, len = 0;
- int ret;
- unsigned char flags = 0;
+#define FLAG_INDEFINITE_LENGTH 0x01 +#define FLAG_MATCHED 0x02 +#define FLAG_LAST_MATCHED 0x04 /* Last tag matched */ +#define FLAG_CONS 0x20 /* Corresponds to CONS bit in the opcode tag
* - ie. whether or not we are going to parse* a compound type.*/+#define NR_CONS_STACK 10
- unsigned short cons_dp_stack[NR_CONS_STACK];
- unsigned short cons_datalen_stack[NR_CONS_STACK];
- unsigned char cons_hdrlen_stack[NR_CONS_STACK];
+#define NR_JUMP_STACK 10
- unsigned char jump_stack[NR_JUMP_STACK];
- if (datalen > 65535)
return -EMSGSIZE;+next_op:
- pr_debug("next_op: pc=\e[32m%zu\e[m/%zu dp=\e[33m%zu\e[m/%zu C=%d J=%d\n",
pc, machlen, dp, datalen, csp, jsp);- if (unlikely(pc >= machlen))
goto machine_overrun_error;- op = machine[pc];
- if (unlikely(pc + asn1_op_lengths[op] > machlen))
goto machine_overrun_error;- /* If this command is meant to match a tag, then do that before
* evaluating the command.*/- if (op <= ASN1_OP__MATCHES_TAG) {
unsigned char tmp;/* Skip conditional matches if possible */if ((op & ASN1_OP_MATCH__COND && flags & FLAG_MATCHED) ||(op & ASN1_OP_MATCH__SKIP && dp == datalen)) {flags &= ~FLAG_LAST_MATCHED;pc += asn1_op_lengths[op];goto next_op;}flags = 0;hdr = 2;/* Extract a tag from the data */if (unlikely(datalen - dp < 2))goto data_overrun_error;tag = data[dp++];if (unlikely((tag & 0x1f) == ASN1_LONG_TAG))goto long_tag_not_supported;if (op & ASN1_OP_MATCH__ANY) {pr_debug("- any %02x\n", tag);} else {/* Extract the tag from the machine* - Either CONS or PRIM are permitted in the data if* CONS is not set in the op stream, otherwise CONS* is mandatory.*/optag = machine[pc + 1];flags |= optag & FLAG_CONS;/* Determine whether the tag matched */tmp = optag ^ tag;tmp &= ~(optag & ASN1_CONS_BIT);pr_debug("- match? %02x %02x %02x\n", tag, optag, tmp);if (tmp != 0) {/* All odd-numbered tags are MATCH_OR_SKIP. */if (op & ASN1_OP_MATCH__SKIP) {pc += asn1_op_lengths[op];dp--;goto next_op;}goto tag_mismatch;}}flags |= FLAG_MATCHED;len = data[dp++];if (len > 0x7f) {if (unlikely(len == ASN1_INDEFINITE_LENGTH)) {/* Indefinite length */if (unlikely(!(tag & ASN1_CONS_BIT)))goto indefinite_len_primitive;flags |= FLAG_INDEFINITE_LENGTH;if (unlikely(2 > datalen - dp))goto data_overrun_error;} else {int n = len - 0x80;if (unlikely(n > 2))goto length_too_long;if (unlikely(n > datalen - dp))goto data_overrun_error;hdr += n;for (len = 0; n > 0; n--) {len <<= 8;len |= data[dp++];}if (unlikely(len > datalen - dp))goto data_overrun_error;}} else {if (unlikely(len > datalen - dp))goto data_overrun_error;}if (flags & FLAG_CONS) {/* For expected compound forms, we stack the positions* of the start and end of the data.*/if (unlikely(csp >= NR_CONS_STACK))goto cons_stack_overflow;cons_dp_stack[csp] = dp;cons_hdrlen_stack[csp] = hdr;if (!(flags & FLAG_INDEFINITE_LENGTH)) {cons_datalen_stack[csp] = datalen;datalen = dp + len;} else {cons_datalen_stack[csp] = 0;}csp++;}pr_debug("- TAG: %02x %zu%s\n",tag, len, flags & FLAG_CONS ? " CONS" : "");tdp = dp;- }
- /* Decide how to handle the operation */
- switch (op) {
- case ASN1_OP_MATCH:
- case ASN1_OP_MATCH_OR_SKIP:
- case ASN1_OP_MATCH_ACT:
- case ASN1_OP_MATCH_ACT_OR_SKIP:
- case ASN1_OP_MATCH_ANY:
- case ASN1_OP_MATCH_ANY_OR_SKIP:
- case ASN1_OP_MATCH_ANY_ACT:
- case ASN1_OP_MATCH_ANY_ACT_OR_SKIP:
- case ASN1_OP_COND_MATCH_OR_SKIP:
- case ASN1_OP_COND_MATCH_ACT_OR_SKIP:
- case ASN1_OP_COND_MATCH_ANY:
- case ASN1_OP_COND_MATCH_ANY_OR_SKIP:
- case ASN1_OP_COND_MATCH_ANY_ACT:
- case ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP:
if (!(flags & FLAG_CONS)) {if (flags & FLAG_INDEFINITE_LENGTH) {size_t tmp = dp;ret = asn1_find_indefinite_length(data, datalen, &tmp, &len, &errmsg);if (ret < 0)goto error;}pr_debug("- LEAF: %zu\n", len);}if (op & ASN1_OP_MATCH__ACT) {unsigned char act;if (op & ASN1_OP_MATCH__ANY)act = machine[pc + 1];elseact = machine[pc + 2];ret = actions[act](context, hdr, tag, data + dp, len);if (ret < 0)return ret;}if (!(flags & FLAG_CONS))dp += len;pc += asn1_op_lengths[op];goto next_op;- case ASN1_OP_MATCH_JUMP:
- case ASN1_OP_MATCH_JUMP_OR_SKIP:
- case ASN1_OP_COND_MATCH_JUMP_OR_SKIP:
pr_debug("- MATCH_JUMP\n");if (unlikely(jsp == NR_JUMP_STACK))goto jump_stack_overflow;jump_stack[jsp++] = pc + asn1_op_lengths[op];pc = machine[pc + 2];goto next_op;- case ASN1_OP_COND_FAIL:
if (unlikely(!(flags & FLAG_MATCHED)))goto tag_mismatch;pc += asn1_op_lengths[op];goto next_op;- case ASN1_OP_COMPLETE:
if (unlikely(jsp != 0 || csp != 0)) {pr_err("ASN.1 decoder error: Stacks not empty at completion (%u, %u)\n",jsp, csp);return -EBADMSG;}return 0;- case ASN1_OP_END_SET:
- case ASN1_OP_END_SET_ACT:
if (unlikely(!(flags & FLAG_MATCHED)))goto tag_mismatch;/* fall through */- case ASN1_OP_END_SEQ:
- case ASN1_OP_END_SET_OF:
- case ASN1_OP_END_SEQ_OF:
- case ASN1_OP_END_SEQ_ACT:
- case ASN1_OP_END_SET_OF_ACT:
- case ASN1_OP_END_SEQ_OF_ACT:
if (unlikely(csp <= 0))goto cons_stack_underflow;csp--;tdp = cons_dp_stack[csp];hdr = cons_hdrlen_stack[csp];len = datalen;datalen = cons_datalen_stack[csp];pr_debug("- end cons t=%zu dp=%zu l=%zu/%zu\n",tdp, dp, len, datalen);if (datalen == 0) {/* Indefinite length - check for the EOC. */datalen = len;if (unlikely(datalen - dp < 2))goto data_overrun_error;if (data[dp++] != 0) {if (op & ASN1_OP_END__OF) {dp--;csp++;pc = machine[pc + 1];pr_debug("- continue\n");goto next_op;}goto missing_eoc;}if (data[dp++] != 0)goto invalid_eoc;len = dp - tdp - 2;} else {if (dp < len && (op & ASN1_OP_END__OF)) {datalen = len;csp++;pc = machine[pc + 1];pr_debug("- continue\n");goto next_op;}if (dp != len)goto cons_length_error;len -= tdp;pr_debug("- cons len l=%zu d=%zu\n", len, dp - tdp);}if (op & ASN1_OP_END__ACT) {unsigned char act;if (op & ASN1_OP_END__OF)act = machine[pc + 2];elseact = machine[pc + 1];ret = actions[act](context, hdr, 0, data + tdp, len);if (ret < 0)return ret;}pc += asn1_op_lengths[op];goto next_op;- case ASN1_OP_MAYBE_ACT:
if (!(flags & FLAG_LAST_MATCHED)) {pc += asn1_op_lengths[op];goto next_op;}/* fall through */- case ASN1_OP_ACT:
ret = actions[machine[pc + 1]](context, hdr, tag, data + tdp, len);if (ret < 0)return ret;pc += asn1_op_lengths[op];goto next_op;- case ASN1_OP_RETURN:
if (unlikely(jsp <= 0))goto jump_stack_underflow;pc = jump_stack[--jsp];flags |= FLAG_MATCHED | FLAG_LAST_MATCHED;goto next_op;- default:
break;- }
- /* Shouldn't reach here */
- pr_err("ASN.1 decoder error: Found reserved opcode (%u) pc=%zu\n",
op, pc);- return -EBADMSG;
+data_overrun_error:
- errmsg = "Data overrun error";
- goto error;
+machine_overrun_error:
- errmsg = "Machine overrun error";
- goto error;
+jump_stack_underflow:
- errmsg = "Jump stack underflow";
- goto error;
+jump_stack_overflow:
- errmsg = "Jump stack overflow";
- goto error;
+cons_stack_underflow:
- errmsg = "Cons stack underflow";
- goto error;
+cons_stack_overflow:
- errmsg = "Cons stack overflow";
- goto error;
+cons_length_error:
- errmsg = "Cons length error";
- goto error;
+missing_eoc:
- errmsg = "Missing EOC in indefinite len cons";
- goto error;
+invalid_eoc:
- errmsg = "Invalid length EOC";
- goto error;
+length_too_long:
- errmsg = "Unsupported length";
- goto error;
+indefinite_len_primitive:
- errmsg = "Indefinite len primitive not permitted";
- goto error;
+tag_mismatch:
- errmsg = "Unexpected tag";
- goto error;
+long_tag_not_supported:
- errmsg = "Long tag not supported";
+error:
- pr_debug("\nASN1: %s [m=%zu d=%zu ot=%02x t=%02x l=%zu]\n",
errmsg, pc, dp, optag, tag, len);- return -EBADMSG;
+} +EXPORT_SYMBOL_GPL(asn1_ber_decoder);
+MODULE_LICENSE("GPL");