[U-Boot] [PATCH v1 06/11] lib: add asn1 decoder

AKASHI Takahiro
2019-10-17T07:02:23Z

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 at 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];
> >+ else
> >+ act = 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];
> >+ else
> >+ act = 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");
> >
>