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Diffstat (limited to '')
| -rw-r--r-- | lib/minitasn1/decoding.c | 2478 |
1 files changed, 2478 insertions, 0 deletions
diff --git a/lib/minitasn1/decoding.c b/lib/minitasn1/decoding.c new file mode 100644 index 0000000..378219c --- /dev/null +++ b/lib/minitasn1/decoding.c @@ -0,0 +1,2478 @@ +/* + * Copyright (C) 2002-2021 Free Software Foundation, Inc. + * + * This file is part of LIBTASN1. + * + * The LIBTASN1 library is free software; you can redistribute it + * and/or modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA + */ + + +/*****************************************************/ +/* File: decoding.c */ +/* Description: Functions to manage DER decoding */ +/*****************************************************/ + +#include <int.h> +#include <parser_aux.h> +#include <gstr.h> +#include <structure.h> +#include <element.h> +#include <limits.h> +#include <intprops.h> +#include "c-ctype.h" + +#ifdef DEBUG +# define warn() fprintf(stderr, "%s: %d\n", __func__, __LINE__) +#else +# define warn() +#endif + +#define IS_ERR(len, flags) (len < -1 || ((flags & ASN1_DECODE_FLAG_STRICT_DER) && len < 0)) + +#define HAVE_TWO(x) (x>=2?1:0) + +/* Decoding flags (dflags) used in several decoding functions. + * DECODE_FLAG_HAVE_TAG: The provided buffer includes a tag + * DECODE_FLAG_CONSTRUCTED: The provided buffer is of indefinite encoding (useful + * when no tags are present). + * DECODE_FLAG_LEVEL1: Internal flag to indicate a level of recursion for BER strings. + * DECODE_FLAG_LEVEL2: Internal flag to indicate two levels of recursion for BER strings. + * DECODE_FLAG_LEVEL3: Internal flag to indicate three levels of recursion for BER strings. + * This is the maximum levels of recursion possible to prevent stack + * exhaustion. + */ + +#define DECODE_FLAG_HAVE_TAG 1 +#define DECODE_FLAG_CONSTRUCTED (1<<1) +#define DECODE_FLAG_LEVEL1 (1<<2) +#define DECODE_FLAG_LEVEL2 (1<<3) +#define DECODE_FLAG_LEVEL3 (1<<4) + +#define DECR_LEN(l, s) do { \ + l -= s; \ + if (l < 0) { \ + warn(); \ + result = ASN1_DER_ERROR; \ + goto cleanup; \ + } \ + } while (0) + +static int +_asn1_get_indefinite_length_string (const unsigned char *der, int der_len, int *len); + +static int +_asn1_decode_simple_ber (unsigned int etype, const unsigned char *der, + unsigned int _der_len, unsigned char **str, + unsigned int *str_len, unsigned int *ber_len, + unsigned dflags); + +static int +_asn1_decode_simple_der (unsigned int etype, const unsigned char *der, + unsigned int _der_len, const unsigned char **str, + unsigned int *str_len, unsigned dflags); + +static void +_asn1_error_description_tag_error (asn1_node node, char *ErrorDescription) +{ + + Estrcpy (ErrorDescription, ":: tag error near element '"); + _asn1_hierarchical_name (node, ErrorDescription + strlen (ErrorDescription), + ASN1_MAX_ERROR_DESCRIPTION_SIZE - 40); + Estrcat (ErrorDescription, "'"); + +} + +/** + * asn1_get_length_der: + * @der: DER data to decode. + * @der_len: Length of DER data to decode. + * @len: Output variable containing the length of the DER length field. + * + * Extract a length field from DER data. + * + * Returns: Return the decoded length value, or -1 on indefinite + * length, or -2 when the value was too big to fit in a int, or -4 + * when the decoded length value plus @len would exceed @der_len. + **/ +long +asn1_get_length_der (const unsigned char *der, int der_len, int *len) +{ + unsigned int ans; + int k, punt, sum; + + *len = 0; + if (der_len <= 0) + return 0; + + if (!(der[0] & 128)) + { + /* short form */ + *len = 1; + ans = der[0]; + } + else + { + /* Long form */ + k = der[0] & 0x7F; + punt = 1; + if (k) + { /* definite length method */ + ans = 0; + while (punt <= k && punt < der_len) + { + if (INT_MULTIPLY_OVERFLOW (ans, 256)) + return -2; + ans *= 256; + + if (INT_ADD_OVERFLOW (ans, ((unsigned) der[punt]))) + return -2; + ans += der[punt]; + punt++; + } + } + else + { /* indefinite length method */ + *len = punt; + return -1; + } + + *len = punt; + } + + sum = ans; + if (ans >= INT_MAX || INT_ADD_OVERFLOW (sum, (*len))) + return -2; + sum += *len; + + if (sum > der_len) + return -4; + + return ans; +} + +/** + * asn1_get_tag_der: + * @der: DER data to decode. + * @der_len: Length of DER data to decode. + * @cls: Output variable containing decoded class. + * @len: Output variable containing the length of the DER TAG data. + * @tag: Output variable containing the decoded tag (may be %NULL). + * + * Decode the class and TAG from DER code. + * + * Returns: Returns %ASN1_SUCCESS on success, or an error. + **/ +int +asn1_get_tag_der (const unsigned char *der, int der_len, + unsigned char *cls, int *len, unsigned long *tag) +{ + unsigned int ris; + int punt; + + if (der == NULL || der_len < 2 || len == NULL) + return ASN1_DER_ERROR; + + *cls = der[0] & 0xE0; + if ((der[0] & 0x1F) != 0x1F) + { + /* short form */ + *len = 1; + ris = der[0] & 0x1F; + } + else + { + /* Long form */ + punt = 1; + ris = 0; + while (punt < der_len && der[punt] & 128) + { + + if (INT_MULTIPLY_OVERFLOW (ris, 128)) + return ASN1_DER_ERROR; + ris *= 128; + + if (INT_ADD_OVERFLOW (ris, ((unsigned) (der[punt] & 0x7F)))) + return ASN1_DER_ERROR; + ris += (der[punt] & 0x7F); + punt++; + } + + if (punt >= der_len) + return ASN1_DER_ERROR; + + if (INT_MULTIPLY_OVERFLOW (ris, 128)) + return ASN1_DER_ERROR; + ris *= 128; + + if (INT_ADD_OVERFLOW (ris, ((unsigned) (der[punt] & 0x7F)))) + return ASN1_DER_ERROR; + ris += (der[punt] & 0x7F); + punt++; + + *len = punt; + } + + if (tag) + *tag = ris; + return ASN1_SUCCESS; +} + +/** + * asn1_get_length_ber: + * @ber: BER data to decode. + * @ber_len: Length of BER data to decode. + * @len: Output variable containing the length of the BER length field. + * + * Extract a length field from BER data. The difference to + * asn1_get_length_der() is that this function will return a length + * even if the value has indefinite encoding. + * + * Returns: Return the decoded length value, or negative value when + * the value was too big. + * + * Since: 2.0 + **/ +long +asn1_get_length_ber (const unsigned char *ber, int ber_len, int *len) +{ + int ret; + long err; + + ret = asn1_get_length_der (ber, ber_len, len); + + if (ret == -1 && ber_len > 1) + { /* indefinite length method */ + err = _asn1_get_indefinite_length_string (ber + 1, ber_len-1, &ret); + if (err != ASN1_SUCCESS) + return -3; + } + + return ret; +} + +/** + * asn1_get_octet_der: + * @der: DER data to decode containing the OCTET SEQUENCE. + * @der_len: The length of the @der data to decode. + * @ret_len: Output variable containing the encoded length of the DER data. + * @str: Pre-allocated output buffer to put decoded OCTET SEQUENCE in. + * @str_size: Length of pre-allocated output buffer. + * @str_len: Output variable containing the length of the contents of the OCTET SEQUENCE. + * + * Extract an OCTET SEQUENCE from DER data. Note that this function + * expects the DER data past the tag field, i.e., the length and + * content octets. + * + * Returns: Returns %ASN1_SUCCESS on success, or an error. + **/ +int +asn1_get_octet_der (const unsigned char *der, int der_len, + int *ret_len, unsigned char *str, int str_size, + int *str_len) +{ + int len_len = 0; + + if (der_len <= 0) + return ASN1_GENERIC_ERROR; + + *str_len = asn1_get_length_der (der, der_len, &len_len); + + if (*str_len < 0) + return ASN1_DER_ERROR; + + *ret_len = *str_len + len_len; + if (str_size >= *str_len) + { + if (*str_len > 0 && str != NULL) + memcpy (str, der + len_len, *str_len); + } + else + { + return ASN1_MEM_ERROR; + } + + return ASN1_SUCCESS; +} + + +/*- + * _asn1_get_time_der: + * @type: %ASN1_ETYPE_GENERALIZED_TIME or %ASN1_ETYPE_UTC_TIME + * @der: DER data to decode containing the time + * @der_len: Length of DER data to decode. + * @ret_len: Output variable containing the length of the DER data. + * @str: Pre-allocated output buffer to put the textual time in. + * @str_size: Length of pre-allocated output buffer. + * @flags: Zero or %ASN1_DECODE_FLAG_STRICT_DER + * + * Performs basic checks in the DER encoded time object and returns its textual form. + * The textual form will be in the YYYYMMDD000000Z format for GeneralizedTime + * and YYMMDD000000Z for UTCTime. + * + * Returns: %ASN1_SUCCESS on success, or an error. + -*/ +static int +_asn1_get_time_der (unsigned type, const unsigned char *der, int der_len, int *ret_len, + char *str, int str_size, unsigned flags) +{ + int len_len, str_len; + unsigned i; + unsigned sign_count = 0; + unsigned dot_count = 0; + const unsigned char *p; + + if (der_len <= 0 || str == NULL) + return ASN1_DER_ERROR; + + str_len = asn1_get_length_der (der, der_len, &len_len); + if (str_len <= 0 || str_size < str_len) + return ASN1_DER_ERROR; + + /* perform some sanity checks on the data */ + if (str_len < 8) + { + warn(); + return ASN1_TIME_ENCODING_ERROR; + } + + if ((flags & ASN1_DECODE_FLAG_STRICT_DER) && !(flags & ASN1_DECODE_FLAG_ALLOW_INCORRECT_TIME)) + { + p = &der[len_len]; + for (i=0;i<(unsigned)(str_len-1);i++) + { + if (c_isdigit(p[i]) == 0) + { + if (type == ASN1_ETYPE_GENERALIZED_TIME) + { + /* tolerate lax encodings */ + if (p[i] == '.' && dot_count == 0) + { + dot_count++; + continue; + } + + /* This is not really valid DER, but there are + * structures using that */ + if (!(flags & ASN1_DECODE_FLAG_STRICT_DER) && + (p[i] == '+' || p[i] == '-') && sign_count == 0) + { + sign_count++; + continue; + } + } + + warn(); + return ASN1_TIME_ENCODING_ERROR; + } + } + + if (sign_count == 0 && p[str_len-1] != 'Z') + { + warn(); + return ASN1_TIME_ENCODING_ERROR; + } + } + memcpy (str, der + len_len, str_len); + str[str_len] = 0; + *ret_len = str_len + len_len; + + return ASN1_SUCCESS; +} + +/** + * asn1_get_object_id_der: + * @der: DER data to decode containing the OBJECT IDENTIFIER + * @der_len: Length of DER data to decode. + * @ret_len: Output variable containing the length of the DER data. + * @str: Pre-allocated output buffer to put the textual object id in. + * @str_size: Length of pre-allocated output buffer. + * + * Converts a DER encoded object identifier to its textual form. This + * function expects the DER object identifier without the tag. + * + * Returns: %ASN1_SUCCESS on success, or an error. + **/ +int +asn1_get_object_id_der (const unsigned char *der, int der_len, int *ret_len, + char *str, int str_size) +{ + int len_len, len, k; + int leading, parsed; + char temp[LTOSTR_MAX_SIZE]; + uint64_t val, val1, val0; + + *ret_len = 0; + if (str && str_size > 0) + str[0] = 0; /* no oid */ + + if (str == NULL || der_len <= 0) + return ASN1_GENERIC_ERROR; + + len = asn1_get_length_der (der, der_len, &len_len); + + if (len <= 0 || len + len_len > der_len) + return ASN1_DER_ERROR; + + /* leading octet can never be 0x80 */ + if (der[len_len] == 0x80) + return ASN1_DER_ERROR; + + val0 = 0; + + for (k = 0; k < len; k++) + { + if (INT_LEFT_SHIFT_OVERFLOW (val0, 7)) + return ASN1_DER_ERROR; + + val0 <<= 7; + val0 |= der[len_len + k] & 0x7F; + if (!(der[len_len + k] & 0x80)) + break; + } + parsed = ++k; + + /* val0 = (X*40) + Y, X={0,1,2}, Y<=39 when X={0,1} */ + /* X = val, Y = val1 */ + + /* check if X == 0 */ + val = 0; + val1 = val0; + if (val1 > 39) + { + val = 1; + val1 = val0 - 40; + if (val1 > 39) + { + val = 2; + val1 = val0 - 80; + } + } + + _asn1_str_cpy (str, str_size, _asn1_ltostr (val, temp)); + _asn1_str_cat (str, str_size, "."); + _asn1_str_cat (str, str_size, _asn1_ltostr (val1, temp)); + + val = 0; + leading = 1; + for (k = parsed; k < len; k++) + { + /* X.690 mandates that the leading byte must never be 0x80 + */ + if (leading != 0 && der[len_len + k] == 0x80) + return ASN1_DER_ERROR; + leading = 0; + + /* check for wrap around */ + if (INT_LEFT_SHIFT_OVERFLOW (val, 7)) + return ASN1_DER_ERROR; + + val = val << 7; + val |= der[len_len + k] & 0x7F; + + if (!(der[len_len + k] & 0x80)) + { + _asn1_str_cat (str, str_size, "."); + _asn1_str_cat (str, str_size, _asn1_ltostr (val, temp)); + val = 0; + leading = 1; + } + } + + if (INT_ADD_OVERFLOW (len, len_len)) + return ASN1_DER_ERROR; + + *ret_len = len + len_len; + + return ASN1_SUCCESS; +} + +/** + * asn1_get_bit_der: + * @der: DER data to decode containing the BIT SEQUENCE. + * @der_len: Length of DER data to decode. + * @ret_len: Output variable containing the length of the DER data. + * @str: Pre-allocated output buffer to put decoded BIT SEQUENCE in. + * @str_size: Length of pre-allocated output buffer. + * @bit_len: Output variable containing the size of the BIT SEQUENCE. + * + * Extract a BIT SEQUENCE from DER data. + * + * Returns: %ASN1_SUCCESS on success, or an error. + **/ +int +asn1_get_bit_der (const unsigned char *der, int der_len, + int *ret_len, unsigned char *str, int str_size, + int *bit_len) +{ + int len_len = 0, len_byte; + + if (der_len <= 0) + return ASN1_GENERIC_ERROR; + + len_byte = asn1_get_length_der (der, der_len, &len_len) - 1; + if (len_byte < 0) + return ASN1_DER_ERROR; + + *ret_len = len_byte + len_len + 1; + *bit_len = len_byte * 8 - der[len_len]; + + if (*bit_len < 0) + return ASN1_DER_ERROR; + + if (str_size >= len_byte) + { + if (len_byte > 0 && str) + memcpy (str, der + len_len + 1, len_byte); + } + else + { + return ASN1_MEM_ERROR; + } + + return ASN1_SUCCESS; +} + +/* tag_len: the total tag length (explicit+inner) + * inner_tag_len: the inner_tag length + */ +static int +_asn1_extract_tag_der (asn1_node node, const unsigned char *der, int der_len, + int *tag_len, int *inner_tag_len, unsigned flags) +{ + asn1_node p; + int counter, len2, len3, is_tag_implicit; + int result; + unsigned long tag, tag_implicit = 0; + unsigned char class, class2, class_implicit = 0; + + if (der_len <= 0) + return ASN1_GENERIC_ERROR; + + counter = is_tag_implicit = 0; + + if (node->type & CONST_TAG) + { + p = node->down; + while (p) + { + if (type_field (p->type) == ASN1_ETYPE_TAG) + { + if (p->type & CONST_APPLICATION) + class2 = ASN1_CLASS_APPLICATION; + else if (p->type & CONST_UNIVERSAL) + class2 = ASN1_CLASS_UNIVERSAL; + else if (p->type & CONST_PRIVATE) + class2 = ASN1_CLASS_PRIVATE; + else + class2 = ASN1_CLASS_CONTEXT_SPECIFIC; + + if (p->type & CONST_EXPLICIT) + { + if (asn1_get_tag_der + (der + counter, der_len, &class, &len2, + &tag) != ASN1_SUCCESS) + return ASN1_DER_ERROR; + + DECR_LEN(der_len, len2); + counter += len2; + + if (flags & ASN1_DECODE_FLAG_STRICT_DER) + len3 = + asn1_get_length_der (der + counter, der_len, + &len2); + else + len3 = + asn1_get_length_ber (der + counter, der_len, + &len2); + if (len3 < 0) + return ASN1_DER_ERROR; + + DECR_LEN(der_len, len2); + counter += len2; + + if (!is_tag_implicit) + { + if ((class != (class2 | ASN1_CLASS_STRUCTURED)) || + (tag != strtoul ((char *) p->value, NULL, 10))) + return ASN1_TAG_ERROR; + } + else + { /* ASN1_TAG_IMPLICIT */ + if ((class != class_implicit) || (tag != tag_implicit)) + return ASN1_TAG_ERROR; + } + is_tag_implicit = 0; + } + else + { /* ASN1_TAG_IMPLICIT */ + if (!is_tag_implicit) + { + if ((type_field (node->type) == ASN1_ETYPE_SEQUENCE) || + (type_field (node->type) == ASN1_ETYPE_SEQUENCE_OF) + || (type_field (node->type) == ASN1_ETYPE_SET) + || (type_field (node->type) == ASN1_ETYPE_SET_OF)) + class2 |= ASN1_CLASS_STRUCTURED; + class_implicit = class2; + tag_implicit = strtoul ((char *) p->value, NULL, 10); + is_tag_implicit = 1; + } + } + } + p = p->right; + } + } + + if (is_tag_implicit) + { + if (asn1_get_tag_der + (der + counter, der_len, &class, &len2, + &tag) != ASN1_SUCCESS) + return ASN1_DER_ERROR; + + DECR_LEN(der_len, len2); + + if ((class != class_implicit) || (tag != tag_implicit)) + { + if (type_field (node->type) == ASN1_ETYPE_OCTET_STRING) + { + class_implicit |= ASN1_CLASS_STRUCTURED; + if ((class != class_implicit) || (tag != tag_implicit)) + return ASN1_TAG_ERROR; + } + else + return ASN1_TAG_ERROR; + } + } + else + { + unsigned type = type_field (node->type); + if (type == ASN1_ETYPE_TAG) + { + *tag_len = 0; + if (inner_tag_len) + *inner_tag_len = 0; + return ASN1_SUCCESS; + } + + if (asn1_get_tag_der + (der + counter, der_len, &class, &len2, + &tag) != ASN1_SUCCESS) + return ASN1_DER_ERROR; + + DECR_LEN(der_len, len2); + + switch (type) + { + case ASN1_ETYPE_NULL: + case ASN1_ETYPE_BOOLEAN: + case ASN1_ETYPE_INTEGER: + case ASN1_ETYPE_ENUMERATED: + case ASN1_ETYPE_OBJECT_ID: + case ASN1_ETYPE_GENERALSTRING: + case ASN1_ETYPE_NUMERIC_STRING: + case ASN1_ETYPE_IA5_STRING: + case ASN1_ETYPE_TELETEX_STRING: + case ASN1_ETYPE_PRINTABLE_STRING: + case ASN1_ETYPE_UNIVERSAL_STRING: + case ASN1_ETYPE_BMP_STRING: + case ASN1_ETYPE_UTF8_STRING: + case ASN1_ETYPE_VISIBLE_STRING: + case ASN1_ETYPE_BIT_STRING: + case ASN1_ETYPE_SEQUENCE: + case ASN1_ETYPE_SEQUENCE_OF: + case ASN1_ETYPE_SET: + case ASN1_ETYPE_SET_OF: + case ASN1_ETYPE_GENERALIZED_TIME: + case ASN1_ETYPE_UTC_TIME: + if ((class != _asn1_tags[type].class) + || (tag != _asn1_tags[type].tag)) + return ASN1_DER_ERROR; + break; + + case ASN1_ETYPE_OCTET_STRING: + /* OCTET STRING is handled differently to allow + * BER encodings (structured class). */ + if (((class != ASN1_CLASS_UNIVERSAL) + && (class != (ASN1_CLASS_UNIVERSAL | ASN1_CLASS_STRUCTURED))) + || (tag != ASN1_TAG_OCTET_STRING)) + return ASN1_DER_ERROR; + break; + case ASN1_ETYPE_ANY: + counter -= len2; + break; + case ASN1_ETYPE_CHOICE: + counter -= len2; + break; + default: + return ASN1_DER_ERROR; + break; + } + } + + counter += len2; + *tag_len = counter; + if (inner_tag_len) + *inner_tag_len = len2; + return ASN1_SUCCESS; + +cleanup: + return result; +} + +static int +extract_tag_der_recursive(asn1_node node, const unsigned char *der, int der_len, + int *ret_len, int *inner_len, unsigned flags) +{ +asn1_node p; +int ris = ASN1_DER_ERROR; + + if (type_field (node->type) == ASN1_ETYPE_CHOICE) + { + p = node->down; + while (p) + { + ris = _asn1_extract_tag_der (p, der, der_len, ret_len, inner_len, flags); + if (ris == ASN1_SUCCESS) + break; + p = p->right; + } + + *ret_len = 0; + return ris; + } + else + return _asn1_extract_tag_der (node, der, der_len, ret_len, inner_len, flags); +} + +static int +_asn1_delete_not_used (asn1_node node) +{ + asn1_node p, p2; + + if (node == NULL) + return ASN1_ELEMENT_NOT_FOUND; + + p = node; + while (p) + { + if (p->type & CONST_NOT_USED) + { + p2 = NULL; + if (p != node) + { + p2 = _asn1_find_left (p); + if (!p2) + p2 = _asn1_find_up (p); + } + asn1_delete_structure (&p); + p = p2; + } + + if (!p) + break; /* reach node */ + + if (p->down) + { + p = p->down; + } + else + { + if (p == node) + p = NULL; + else if (p->right) + p = p->right; + else + { + while (1) + { + p = _asn1_find_up (p); + if (p == node) + { + p = NULL; + break; + } + if (p->right) + { + p = p->right; + break; + } + } + } + } + } + return ASN1_SUCCESS; +} + +static int +_asn1_get_indefinite_length_string (const unsigned char *der, + int der_len, int *len) +{ + int len2, len3, counter, indefinite; + int result; + unsigned long tag; + unsigned char class; + + counter = indefinite = 0; + + while (1) + { + if (HAVE_TWO(der_len) && (der[counter] == 0) && (der[counter + 1] == 0)) + { + counter += 2; + DECR_LEN(der_len, 2); + + indefinite--; + if (indefinite <= 0) + break; + else + continue; + } + + if (asn1_get_tag_der + (der + counter, der_len, &class, &len2, + &tag) != ASN1_SUCCESS) + return ASN1_DER_ERROR; + + DECR_LEN(der_len, len2); + counter += len2; + + len2 = asn1_get_length_der (der + counter, der_len, &len3); + if (len2 < -1) + return ASN1_DER_ERROR; + + if (len2 == -1) + { + indefinite++; + counter += 1; + DECR_LEN(der_len, 1); + } + else + { + counter += len2 + len3; + DECR_LEN(der_len, len2+len3); + } + } + + *len = counter; + return ASN1_SUCCESS; + +cleanup: + return result; +} + +static void delete_unneeded_choice_fields(asn1_node p) +{ + asn1_node p2; + + while (p->right) + { + p2 = p->right; + asn1_delete_structure (&p2); + } +} + + +/** + * asn1_der_decoding2 + * @element: pointer to an ASN1 structure. + * @ider: vector that contains the DER encoding. + * @max_ider_len: pointer to an integer giving the information about the + * maximal number of bytes occupied by *@ider. The real size of the DER + * encoding is returned through this pointer. + * @flags: flags controlling the behaviour of the function. + * @errorDescription: null-terminated string contains details when an + * error occurred. + * + * Fill the structure *@element with values of a DER encoding string. The + * structure must just be created with function asn1_create_element(). + * + * If %ASN1_DECODE_FLAG_ALLOW_PADDING flag is set then the function will ignore + * padding after the decoded DER data. Upon a successful return the value of + * *@max_ider_len will be set to the number of bytes decoded. + * + * If %ASN1_DECODE_FLAG_STRICT_DER flag is set then the function will + * not decode any BER-encoded elements. + * + * Returns: %ASN1_SUCCESS if DER encoding OK, %ASN1_ELEMENT_NOT_FOUND + * if @ELEMENT is %NULL, and %ASN1_TAG_ERROR or + * %ASN1_DER_ERROR if the der encoding doesn't match the structure + * name (*@ELEMENT deleted). + **/ +int +asn1_der_decoding2 (asn1_node *element, const void *ider, int *max_ider_len, + unsigned int flags, char *errorDescription) +{ + asn1_node node, p, p2, p3; + char temp[128]; + int counter, len2, len3, len4, move, ris, tlen; + struct node_tail_cache_st tcache = {NULL, NULL}; + unsigned char class; + unsigned long tag; + int tag_len; + int indefinite, result, total_len = *max_ider_len, ider_len = *max_ider_len; + int inner_tag_len; + unsigned char *ptmp; + const unsigned char *ptag; + const unsigned char *der = ider; + + node = *element; + + if (errorDescription != NULL) + errorDescription[0] = 0; + + if (node == NULL) + return ASN1_ELEMENT_NOT_FOUND; + + if (node->type & CONST_OPTION) + { + result = ASN1_GENERIC_ERROR; + warn(); + goto cleanup; + } + + counter = 0; + move = DOWN; + p = node; + while (1) + { + tag_len = 0; + inner_tag_len = 0; + ris = ASN1_SUCCESS; + if (move != UP) + { + if (p->type & CONST_SET) + { + p2 = _asn1_find_up (p); + len2 = p2->tmp_ival; + if (len2 == -1) + { + if (HAVE_TWO(ider_len) && !der[counter] && !der[counter + 1]) + { + p = p2; + move = UP; + counter += 2; + DECR_LEN(ider_len, 2); + continue; + } + } + else if (counter == len2) + { + p = p2; + move = UP; + continue; + } + else if (counter > len2) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + p2 = p2->down; + while (p2) + { + if ((p2->type & CONST_SET) && (p2->type & CONST_NOT_USED)) + { + ris = + extract_tag_der_recursive (p2, der + counter, + ider_len, &len2, NULL, flags); + if (ris == ASN1_SUCCESS) + { + p2->type &= ~CONST_NOT_USED; + p = p2; + break; + } + } + p2 = p2->right; + } + if (p2 == NULL) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + } + + /* the position in the DER structure this starts */ + p->start = counter; + p->end = total_len - 1; + + if ((p->type & CONST_OPTION) || (p->type & CONST_DEFAULT)) + { + p2 = _asn1_find_up (p); + len2 = p2->tmp_ival; + if (counter == len2) + { + if (p->right) + { + p2 = p->right; + move = RIGHT; + } + else + move = UP; + + if (p->type & CONST_OPTION) + asn1_delete_structure (&p); + + p = p2; + continue; + } + } + + if (type_field (p->type) == ASN1_ETYPE_CHOICE) + { + while (p->down) + { + ris = + extract_tag_der_recursive (p->down, der + counter, + ider_len, &len2, NULL, flags); + + if (ris == ASN1_SUCCESS) + { + delete_unneeded_choice_fields(p->down); + break; + } + else if (ris == ASN1_ERROR_TYPE_ANY) + { + result = ASN1_ERROR_TYPE_ANY; + warn(); + goto cleanup; + } + else + { + p2 = p->down; + asn1_delete_structure (&p2); + } + } + + if (p->down == NULL) + { + if (!(p->type & CONST_OPTION)) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + } + else if (type_field (p->type) != ASN1_ETYPE_CHOICE) + p = p->down; + + p->start = counter; + } + + if ((p->type & CONST_OPTION) || (p->type & CONST_DEFAULT)) + { + p2 = _asn1_find_up (p); + len2 = p2->tmp_ival; + + if ((len2 != -1) && (counter > len2)) + ris = ASN1_TAG_ERROR; + } + + if (ris == ASN1_SUCCESS) + ris = + extract_tag_der_recursive (p, der + counter, ider_len, + &tag_len, &inner_tag_len, flags); + + if (ris != ASN1_SUCCESS) + { + if (p->type & CONST_OPTION) + { + p->type |= CONST_NOT_USED; + move = RIGHT; + } + else if (p->type & CONST_DEFAULT) + { + _asn1_set_value (p, NULL, 0); + move = RIGHT; + } + else + { + if (errorDescription != NULL) + _asn1_error_description_tag_error (p, errorDescription); + + result = ASN1_TAG_ERROR; + warn(); + goto cleanup; + } + } + else + { + DECR_LEN(ider_len, tag_len); + counter += tag_len; + } + } + + if (ris == ASN1_SUCCESS) + { + switch (type_field (p->type)) + { + case ASN1_ETYPE_NULL: + DECR_LEN(ider_len, 1); + if (der[counter]) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + counter++; + move = RIGHT; + break; + case ASN1_ETYPE_BOOLEAN: + DECR_LEN(ider_len, 2); + + if (der[counter++] != 1) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + if (der[counter++] == 0) + _asn1_set_value (p, "F", 1); + else + _asn1_set_value (p, "T", 1); + move = RIGHT; + break; + case ASN1_ETYPE_INTEGER: + case ASN1_ETYPE_ENUMERATED: + len2 = + asn1_get_length_der (der + counter, ider_len, &len3); + if (len2 < 0) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len3+len2); + + _asn1_set_value (p, der + counter, len3 + len2); + counter += len3 + len2; + move = RIGHT; + break; + case ASN1_ETYPE_OBJECT_ID: + result = + asn1_get_object_id_der (der + counter, ider_len, &len2, + temp, sizeof (temp)); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len2); + + tlen = strlen (temp); + if (tlen > 0) + _asn1_set_value (p, temp, tlen + 1); + + counter += len2; + move = RIGHT; + break; + case ASN1_ETYPE_GENERALIZED_TIME: + case ASN1_ETYPE_UTC_TIME: + result = + _asn1_get_time_der (type_field (p->type), der + counter, ider_len, &len2, temp, + sizeof (temp) - 1, flags); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len2); + + tlen = strlen (temp); + if (tlen > 0) + _asn1_set_value (p, temp, tlen); + + counter += len2; + move = RIGHT; + break; + case ASN1_ETYPE_OCTET_STRING: + if (counter < inner_tag_len) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + ptag = der + counter - inner_tag_len; + if ((flags & ASN1_DECODE_FLAG_STRICT_DER) || !(ptag[0] & ASN1_CLASS_STRUCTURED)) + { + if (ptag[0] & ASN1_CLASS_STRUCTURED) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + len2 = + asn1_get_length_der (der + counter, ider_len, &len3); + if (len2 < 0) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len3+len2); + + _asn1_set_value (p, der + counter, len3 + len2); + counter += len3 + len2; + } + else + { + unsigned dflags = 0, vlen, ber_len; + + if (ptag[0] & ASN1_CLASS_STRUCTURED) + dflags |= DECODE_FLAG_CONSTRUCTED; + + result = _asn1_decode_simple_ber(type_field (p->type), der+counter, ider_len, &ptmp, &vlen, &ber_len, dflags); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, ber_len); + + _asn1_set_value_lv (p, ptmp, vlen); + + counter += ber_len; + free(ptmp); + } + move = RIGHT; + break; + case ASN1_ETYPE_GENERALSTRING: + case ASN1_ETYPE_NUMERIC_STRING: + case ASN1_ETYPE_IA5_STRING: + case ASN1_ETYPE_TELETEX_STRING: + case ASN1_ETYPE_PRINTABLE_STRING: + case ASN1_ETYPE_UNIVERSAL_STRING: + case ASN1_ETYPE_BMP_STRING: + case ASN1_ETYPE_UTF8_STRING: + case ASN1_ETYPE_VISIBLE_STRING: + case ASN1_ETYPE_BIT_STRING: + len2 = + asn1_get_length_der (der + counter, ider_len, &len3); + if (len2 < 0) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len3+len2); + + _asn1_set_value (p, der + counter, len3 + len2); + counter += len3 + len2; + move = RIGHT; + break; + case ASN1_ETYPE_SEQUENCE: + case ASN1_ETYPE_SET: + if (move == UP) + { + len2 = p->tmp_ival; + p->tmp_ival = 0; + if (len2 == -1) + { /* indefinite length method */ + DECR_LEN(ider_len, 2); + if ((der[counter]) || der[counter + 1]) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + counter += 2; + } + else + { /* definite length method */ + if (len2 != counter) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + } + move = RIGHT; + } + else + { /* move==DOWN || move==RIGHT */ + len3 = + asn1_get_length_der (der + counter, ider_len, &len2); + if (IS_ERR(len3, flags)) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len2); + counter += len2; + + if (len3 > 0) + { + p->tmp_ival = counter + len3; + move = DOWN; + } + else if (len3 == 0) + { + p2 = p->down; + while (p2) + { + if (type_field (p2->type) != ASN1_ETYPE_TAG) + { + p3 = p2->right; + asn1_delete_structure (&p2); + p2 = p3; + } + else + p2 = p2->right; + } + move = RIGHT; + } + else + { /* indefinite length method */ + p->tmp_ival = -1; + move = DOWN; + } + } + break; + case ASN1_ETYPE_SEQUENCE_OF: + case ASN1_ETYPE_SET_OF: + if (move == UP) + { + len2 = p->tmp_ival; + if (len2 == -1) + { /* indefinite length method */ + if (!HAVE_TWO(ider_len) || ((der[counter]) || der[counter + 1])) + { + result = _asn1_append_sequence_set (p, &tcache); + if (result != 0) + { + warn(); + goto cleanup; + } + p = tcache.tail; + move = RIGHT; + continue; + } + + p->tmp_ival = 0; + tcache.tail = NULL; /* finished decoding this structure */ + tcache.head = NULL; + DECR_LEN(ider_len, 2); + counter += 2; + } + else + { /* definite length method */ + if (len2 > counter) + { + result = _asn1_append_sequence_set (p, &tcache); + if (result != 0) + { + warn(); + goto cleanup; + } + p = tcache.tail; + move = RIGHT; + continue; + } + + p->tmp_ival = 0; + tcache.tail = NULL; /* finished decoding this structure */ + tcache.head = NULL; + + if (len2 != counter) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + } + } + else + { /* move==DOWN || move==RIGHT */ + len3 = + asn1_get_length_der (der + counter, ider_len, &len2); + if (IS_ERR(len3, flags)) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len2); + counter += len2; + if (len3) + { + if (len3 > 0) + { /* definite length method */ + p->tmp_ival = counter + len3; + } + else + { /* indefinite length method */ + p->tmp_ival = -1; + } + + p2 = p->down; + if (p2 == NULL) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + while ((type_field (p2->type) == ASN1_ETYPE_TAG) + || (type_field (p2->type) == ASN1_ETYPE_SIZE)) + p2 = p2->right; + if (p2->right == NULL) + { + result = _asn1_append_sequence_set (p, &tcache); + if (result != 0) + { + warn(); + goto cleanup; + } + } + p = p2; + } + } + move = RIGHT; + break; + case ASN1_ETYPE_ANY: + /* Check indefinite lenth method in an EXPLICIT TAG */ + + if (!(flags & ASN1_DECODE_FLAG_STRICT_DER) && (p->type & CONST_TAG) && + tag_len == 2 && (der[counter - 1] == 0x80)) + indefinite = 1; + else + indefinite = 0; + + if (asn1_get_tag_der + (der + counter, ider_len, &class, &len2, + &tag) != ASN1_SUCCESS) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len2); + + len4 = + asn1_get_length_der (der + counter + len2, + ider_len, &len3); + if (IS_ERR(len4, flags)) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + if (len4 != -1) /* definite */ + { + len2 += len4; + + DECR_LEN(ider_len, len4+len3); + _asn1_set_value_lv (p, der + counter, len2 + len3); + counter += len2 + len3; + } + else /* == -1 */ + { /* indefinite length */ + ider_len += len2; /* undo DECR_LEN */ + + if (counter == 0) + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + + result = + _asn1_get_indefinite_length_string (der + counter, ider_len, &len2); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + DECR_LEN(ider_len, len2); + _asn1_set_value_lv (p, der + counter, len2); + counter += len2; + + } + + /* Check if a couple of 0x00 are present due to an EXPLICIT TAG with + an indefinite length method. */ + if (indefinite) + { + DECR_LEN(ider_len, 2); + if (!der[counter] && !der[counter + 1]) + { + counter += 2; + } + else + { + result = ASN1_DER_ERROR; + warn(); + goto cleanup; + } + } + + move = RIGHT; + break; + default: + move = (move == UP) ? RIGHT : DOWN; + break; + } + } + + if (p) + { + p->end = counter - 1; + } + + if (p == node && move != DOWN) + break; + + if (move == DOWN) + { + if (p->down) + p = p->down; + else + move = RIGHT; + } + if ((move == RIGHT) && !(p->type & CONST_SET)) + { + if (p->right) + p = p->right; + else + move = UP; + } + if (move == UP) + p = _asn1_find_up (p); + } + + _asn1_delete_not_used (*element); + + if ((ider_len < 0) || + (!(flags & ASN1_DECODE_FLAG_ALLOW_PADDING) && (ider_len != 0))) + { + warn(); + result = ASN1_DER_ERROR; + goto cleanup; + } + + *max_ider_len = total_len - ider_len; + + return ASN1_SUCCESS; + +cleanup: + asn1_delete_structure (element); + return result; +} + + +/** + * asn1_der_decoding: + * @element: pointer to an ASN1 structure. + * @ider: vector that contains the DER encoding. + * @ider_len: number of bytes of *@ider: @ider[0]..@ider[len-1]. + * @errorDescription: null-terminated string contains details when an + * error occurred. + * + * Fill the structure *@element with values of a DER encoding + * string. The structure must just be created with function + * asn1_create_element(). + * + * Note that the *@element variable is provided as a pointer for + * historical reasons. + * + * Returns: %ASN1_SUCCESS if DER encoding OK, %ASN1_ELEMENT_NOT_FOUND + * if @ELEMENT is %NULL, and %ASN1_TAG_ERROR or + * %ASN1_DER_ERROR if the der encoding doesn't match the structure + * name (*@ELEMENT deleted). + **/ +int +asn1_der_decoding (asn1_node * element, const void *ider, int ider_len, + char *errorDescription) +{ + return asn1_der_decoding2 (element, ider, &ider_len, 0, errorDescription); +} + +/** + * asn1_der_decoding_element: + * @structure: pointer to an ASN1 structure + * @elementName: name of the element to fill + * @ider: vector that contains the DER encoding of the whole structure. + * @len: number of bytes of *der: der[0]..der[len-1] + * @errorDescription: null-terminated string contains details when an + * error occurred. + * + * Fill the element named @ELEMENTNAME with values of a DER encoding + * string. The structure must just be created with function + * asn1_create_element(). The DER vector must contain the encoding + * string of the whole @STRUCTURE. If an error occurs during the + * decoding procedure, the *@STRUCTURE is deleted and set equal to + * %NULL. + * + * This function is deprecated and may just be an alias to asn1_der_decoding + * in future versions. Use asn1_der_decoding() instead. + * + * Returns: %ASN1_SUCCESS if DER encoding OK, %ASN1_ELEMENT_NOT_FOUND + * if ELEMENT is %NULL or @elementName == NULL, and + * %ASN1_TAG_ERROR or %ASN1_DER_ERROR if the der encoding doesn't + * match the structure @structure (*ELEMENT deleted). + **/ +int +asn1_der_decoding_element (asn1_node * structure, const char *elementName, + const void *ider, int len, char *errorDescription) +{ + return asn1_der_decoding(structure, ider, len, errorDescription); +} + +/** + * asn1_der_decoding_startEnd: + * @element: pointer to an ASN1 element + * @ider: vector that contains the DER encoding. + * @ider_len: number of bytes of *@ider: @ider[0]..@ider[len-1] + * @name_element: an element of NAME structure. + * @start: the position of the first byte of NAME_ELEMENT decoding + * (@ider[*start]) + * @end: the position of the last byte of NAME_ELEMENT decoding + * (@ider[*end]) + * + * Find the start and end point of an element in a DER encoding + * string. I mean that if you have a der encoding and you have already + * used the function asn1_der_decoding() to fill a structure, it may + * happen that you want to find the piece of string concerning an + * element of the structure. + * + * One example is the sequence "tbsCertificate" inside an X509 + * certificate. + * + * Note that since libtasn1 3.7 the @ider and @ider_len parameters + * can be omitted, if the element is already decoded using asn1_der_decoding(). + * + * Returns: %ASN1_SUCCESS if DER encoding OK, %ASN1_ELEMENT_NOT_FOUND + * if ELEMENT is %asn1_node EMPTY or @name_element is not a valid + * element, %ASN1_TAG_ERROR or %ASN1_DER_ERROR if the der encoding + * doesn't match the structure ELEMENT. + **/ +int +asn1_der_decoding_startEnd (asn1_node element, const void *ider, int ider_len, + const char *name_element, int *start, int *end) +{ + asn1_node node, node_to_find; + int result = ASN1_DER_ERROR; + + node = element; + + if (node == NULL) + return ASN1_ELEMENT_NOT_FOUND; + + node_to_find = asn1_find_node (node, name_element); + + if (node_to_find == NULL) + return ASN1_ELEMENT_NOT_FOUND; + + *start = node_to_find->start; + *end = node_to_find->end; + + if (*start == 0 && *end == 0) + { + if (ider == NULL || ider_len == 0) + return ASN1_GENERIC_ERROR; + + /* it seems asn1_der_decoding() wasn't called before. Do it now */ + result = asn1_der_decoding (&node, ider, ider_len, NULL); + if (result != ASN1_SUCCESS) + { + warn(); + return result; + } + + node_to_find = asn1_find_node (node, name_element); + if (node_to_find == NULL) + return ASN1_ELEMENT_NOT_FOUND; + + *start = node_to_find->start; + *end = node_to_find->end; + } + + if (*end < *start) + return ASN1_GENERIC_ERROR; + + return ASN1_SUCCESS; +} + +/** + * asn1_expand_any_defined_by: + * @definitions: ASN1 definitions + * @element: pointer to an ASN1 structure + * + * Expands every "ANY DEFINED BY" element of a structure created from + * a DER decoding process (asn1_der_decoding function). The element + * ANY must be defined by an OBJECT IDENTIFIER. The type used to + * expand the element ANY is the first one following the definition of + * the actual value of the OBJECT IDENTIFIER. + * + * Returns: %ASN1_SUCCESS if Substitution OK, %ASN1_ERROR_TYPE_ANY if + * some "ANY DEFINED BY" element couldn't be expanded due to a + * problem in OBJECT_ID -> TYPE association, or other error codes + * depending on DER decoding. + **/ +int +asn1_expand_any_defined_by (asn1_node_const definitions, asn1_node * element) +{ + char name[2 * ASN1_MAX_NAME_SIZE + 2], + value[ASN1_MAX_NAME_SIZE]; + int retCode = ASN1_SUCCESS, result; + int len, len2, len3; + asn1_node_const p2; + asn1_node p, p3, aux = NULL; + char errorDescription[ASN1_MAX_ERROR_DESCRIPTION_SIZE]; + const char *definitionsName; + + if ((definitions == NULL) || (*element == NULL)) + return ASN1_ELEMENT_NOT_FOUND; + + definitionsName = definitions->name; + + p = *element; + while (p) + { + + switch (type_field (p->type)) + { + case ASN1_ETYPE_ANY: + if ((p->type & CONST_DEFINED_BY) && (p->value)) + { + /* search the "DEF_BY" element */ + p2 = p->down; + while ((p2) && (type_field (p2->type) != ASN1_ETYPE_CONSTANT)) + p2 = p2->right; + + if (!p2) + { + retCode = ASN1_ERROR_TYPE_ANY; + break; + } + + p3 = _asn1_find_up (p); + + if (!p3) + { + retCode = ASN1_ERROR_TYPE_ANY; + break; + } + + p3 = p3->down; + while (p3) + { + if (!(strcmp (p3->name, p2->name))) + break; + p3 = p3->right; + } + + if ((!p3) || (type_field (p3->type) != ASN1_ETYPE_OBJECT_ID) || + (p3->value == NULL)) + { + + p3 = _asn1_find_up (p); + p3 = _asn1_find_up (p3); + + if (!p3) + { + retCode = ASN1_ERROR_TYPE_ANY; + break; + } + + p3 = p3->down; + + while (p3) + { + if (!(strcmp (p3->name, p2->name))) + break; + p3 = p3->right; + } + + if ((!p3) || (type_field (p3->type) != ASN1_ETYPE_OBJECT_ID) + || (p3->value == NULL)) + { + retCode = ASN1_ERROR_TYPE_ANY; + break; + } + } + + /* search the OBJECT_ID into definitions */ + p2 = definitions->down; + while (p2) + { + if ((type_field (p2->type) == ASN1_ETYPE_OBJECT_ID) && + (p2->type & CONST_ASSIGN)) + { + snprintf(name, sizeof(name), "%s.%s", definitionsName, p2->name); + + len = ASN1_MAX_NAME_SIZE; + result = + asn1_read_value (definitions, name, value, &len); + + if ((result == ASN1_SUCCESS) + && (!_asn1_strcmp (p3->value, value))) + { + p2 = p2->right; /* pointer to the structure to + use for expansion */ + while ((p2) && (p2->type & CONST_ASSIGN)) + p2 = p2->right; + + if (p2) + { + snprintf(name, sizeof(name), "%s.%s", definitionsName, p2->name); + + result = + asn1_create_element (definitions, name, &aux); + if (result == ASN1_SUCCESS) + { + _asn1_cpy_name (aux, p); + len2 = + asn1_get_length_der (p->value, + p->value_len, &len3); + if (len2 < 0) + return ASN1_DER_ERROR; + + result = + asn1_der_decoding (&aux, p->value + len3, + len2, + errorDescription); + if (result == ASN1_SUCCESS) + { + + _asn1_set_right (aux, p->right); + _asn1_set_right (p, aux); + + result = asn1_delete_structure (&p); + if (result == ASN1_SUCCESS) + { + p = aux; + aux = NULL; + break; + } + else + { /* error with asn1_delete_structure */ + asn1_delete_structure (&aux); + retCode = result; + break; + } + } + else + { /* error with asn1_der_decoding */ + retCode = result; + break; + } + } + else + { /* error with asn1_create_element */ + retCode = result; + break; + } + } + else + { /* error with the pointer to the structure to exapand */ + retCode = ASN1_ERROR_TYPE_ANY; + break; + } + } + } + p2 = p2->right; + } /* end while */ + + if (!p2) + { + retCode = ASN1_ERROR_TYPE_ANY; + break; + } + + } + break; + default: + break; + } + + + if (p->down) + { + p = p->down; + } + else if (p == *element) + { + p = NULL; + break; + } + else if (p->right) + p = p->right; + else + { + while (1) + { + p = _asn1_find_up (p); + if (p == *element) + { + p = NULL; + break; + } + if (p->right) + { + p = p->right; + break; + } + } + } + } + + return retCode; +} + +/** + * asn1_expand_octet_string: + * @definitions: ASN1 definitions + * @element: pointer to an ASN1 structure + * @octetName: name of the OCTECT STRING field to expand. + * @objectName: name of the OBJECT IDENTIFIER field to use to define + * the type for expansion. + * + * Expands an "OCTET STRING" element of a structure created from a DER + * decoding process (the asn1_der_decoding() function). The type used + * for expansion is the first one following the definition of the + * actual value of the OBJECT IDENTIFIER indicated by OBJECTNAME. + * + * Returns: %ASN1_SUCCESS if substitution OK, %ASN1_ELEMENT_NOT_FOUND + * if @objectName or @octetName are not correct, + * %ASN1_VALUE_NOT_VALID if it wasn't possible to find the type to + * use for expansion, or other errors depending on DER decoding. + **/ +int +asn1_expand_octet_string (asn1_node_const definitions, asn1_node * element, + const char *octetName, const char *objectName) +{ + char name[2 * ASN1_MAX_NAME_SIZE + 1], value[ASN1_MAX_NAME_SIZE]; + int retCode = ASN1_SUCCESS, result; + int len, len2, len3; + asn1_node_const p2; + asn1_node aux = NULL; + asn1_node octetNode = NULL, objectNode = NULL; + char errorDescription[ASN1_MAX_ERROR_DESCRIPTION_SIZE]; + + if ((definitions == NULL) || (*element == NULL)) + return ASN1_ELEMENT_NOT_FOUND; + + octetNode = asn1_find_node (*element, octetName); + if (octetNode == NULL) + return ASN1_ELEMENT_NOT_FOUND; + if (type_field (octetNode->type) != ASN1_ETYPE_OCTET_STRING) + return ASN1_ELEMENT_NOT_FOUND; + if (octetNode->value == NULL) + return ASN1_VALUE_NOT_FOUND; + + objectNode = asn1_find_node (*element, objectName); + if (objectNode == NULL) + return ASN1_ELEMENT_NOT_FOUND; + + if (type_field (objectNode->type) != ASN1_ETYPE_OBJECT_ID) + return ASN1_ELEMENT_NOT_FOUND; + + if (objectNode->value == NULL) + return ASN1_VALUE_NOT_FOUND; + + + /* search the OBJECT_ID into definitions */ + p2 = definitions->down; + while (p2) + { + if ((type_field (p2->type) == ASN1_ETYPE_OBJECT_ID) && + (p2->type & CONST_ASSIGN)) + { + strcpy (name, definitions->name); + strcat (name, "."); + strcat (name, p2->name); + + len = sizeof (value); + result = asn1_read_value (definitions, name, value, &len); + + if ((result == ASN1_SUCCESS) + && (!_asn1_strcmp (objectNode->value, value))) + { + + p2 = p2->right; /* pointer to the structure to + use for expansion */ + while ((p2) && (p2->type & CONST_ASSIGN)) + p2 = p2->right; + + if (p2) + { + strcpy (name, definitions->name); + strcat (name, "."); + strcat (name, p2->name); + + result = asn1_create_element (definitions, name, &aux); + if (result == ASN1_SUCCESS) + { + _asn1_cpy_name (aux, octetNode); + len2 = + asn1_get_length_der (octetNode->value, + octetNode->value_len, &len3); + if (len2 < 0) + return ASN1_DER_ERROR; + + result = + asn1_der_decoding (&aux, octetNode->value + len3, + len2, errorDescription); + if (result == ASN1_SUCCESS) + { + + _asn1_set_right (aux, octetNode->right); + _asn1_set_right (octetNode, aux); + + result = asn1_delete_structure (&octetNode); + if (result == ASN1_SUCCESS) + { + aux = NULL; + break; + } + else + { /* error with asn1_delete_structure */ + asn1_delete_structure (&aux); + retCode = result; + break; + } + } + else + { /* error with asn1_der_decoding */ + retCode = result; + break; + } + } + else + { /* error with asn1_create_element */ + retCode = result; + break; + } + } + else + { /* error with the pointer to the structure to exapand */ + retCode = ASN1_VALUE_NOT_VALID; + break; + } + } + } + + p2 = p2->right; + + } + + if (!p2) + retCode = ASN1_VALUE_NOT_VALID; + + return retCode; +} + +/*- + * _asn1_decode_simple_der: + * @etype: The type of the string to be encoded (ASN1_ETYPE_) + * @der: the encoded string + * @_der_len: the bytes of the encoded string + * @str: a pointer to the data + * @str_len: the length of the data + * @dflags: DECODE_FLAG_* + * + * Decodes a simple DER encoded type (e.g. a string, which is not constructed). + * The output is a pointer inside the @der. + * + * Returns: %ASN1_SUCCESS if successful or an error value. + -*/ +static int +_asn1_decode_simple_der (unsigned int etype, const unsigned char *der, + unsigned int _der_len, const unsigned char **str, + unsigned int *str_len, unsigned dflags) +{ + int tag_len, len_len; + const unsigned char *p; + int der_len = _der_len; + unsigned char class; + unsigned long tag; + long ret; + + if (der == NULL || der_len == 0) + return ASN1_VALUE_NOT_VALID; + + if (ETYPE_OK (etype) == 0 || ETYPE_IS_STRING(etype) == 0) + return ASN1_VALUE_NOT_VALID; + + /* doesn't handle constructed classes */ + class = ETYPE_CLASS(etype); + if (class != ASN1_CLASS_UNIVERSAL) + return ASN1_VALUE_NOT_VALID; + + p = der; + + if (dflags & DECODE_FLAG_HAVE_TAG) + { + ret = asn1_get_tag_der (p, der_len, &class, &tag_len, &tag); + if (ret != ASN1_SUCCESS) + return ret; + + if (class != ETYPE_CLASS (etype) || tag != ETYPE_TAG (etype)) + { + warn(); + return ASN1_DER_ERROR; + } + + p += tag_len; + der_len -= tag_len; + if (der_len <= 0) + return ASN1_DER_ERROR; + } + + ret = asn1_get_length_der (p, der_len, &len_len); + if (ret < 0) + return ASN1_DER_ERROR; + + p += len_len; + der_len -= len_len; + if (der_len <= 0) + return ASN1_DER_ERROR; + + *str_len = ret; + *str = p; + + return ASN1_SUCCESS; +} + +/** + * asn1_decode_simple_der: + * @etype: The type of the string to be encoded (ASN1_ETYPE_) + * @der: the encoded string + * @_der_len: the bytes of the encoded string + * @str: a pointer to the data + * @str_len: the length of the data + * + * Decodes a simple DER encoded type (e.g. a string, which is not constructed). + * The output is a pointer inside the @der. + * + * Returns: %ASN1_SUCCESS if successful or an error value. + **/ +int +asn1_decode_simple_der (unsigned int etype, const unsigned char *der, + unsigned int _der_len, const unsigned char **str, + unsigned int *str_len) +{ + return _asn1_decode_simple_der(etype, der, _der_len, str, str_len, DECODE_FLAG_HAVE_TAG); +} + +static int append(uint8_t **dst, unsigned *dst_size, const unsigned char *src, unsigned src_size) +{ + if (src_size == 0) + return ASN1_SUCCESS; + + *dst = _asn1_realloc(*dst, *dst_size+src_size); + if (*dst == NULL) + return ASN1_MEM_ALLOC_ERROR; + memcpy(*dst + *dst_size, src, src_size); + *dst_size += src_size; + return ASN1_SUCCESS; +} + +/*- + * _asn1_decode_simple_ber: + * @etype: The type of the string to be encoded (ASN1_ETYPE_) + * @der: the encoded string + * @_der_len: the bytes of the encoded string + * @str: a pointer to the data + * @str_len: the length of the data + * @ber_len: the total length occupied by BER (may be %NULL) + * @have_tag: whether a DER tag is included + * + * Decodes a BER encoded type. The output is an allocated value + * of the data. This decodes BER STRINGS only. Other types are + * decoded as DER. + * + * Returns: %ASN1_SUCCESS if successful or an error value. + -*/ +static int +_asn1_decode_simple_ber (unsigned int etype, const unsigned char *der, + unsigned int _der_len, unsigned char **str, + unsigned int *str_len, unsigned int *ber_len, + unsigned dflags) +{ + int tag_len, len_len; + const unsigned char *p; + int der_len = _der_len; + uint8_t *total = NULL; + unsigned total_size = 0; + unsigned char class; + unsigned long tag; + unsigned char *out = NULL; + const unsigned char *cout = NULL; + unsigned out_len; + long result; + + if (ber_len) *ber_len = 0; + + if (der == NULL || der_len == 0) + { + warn(); + return ASN1_VALUE_NOT_VALID; + } + + if (ETYPE_OK (etype) == 0) + { + warn(); + return ASN1_VALUE_NOT_VALID; + } + + /* doesn't handle constructed + definite classes */ + class = ETYPE_CLASS (etype); + if (class != ASN1_CLASS_UNIVERSAL) + { + warn(); + return ASN1_VALUE_NOT_VALID; + } + + p = der; + + if (dflags & DECODE_FLAG_HAVE_TAG) + { + result = asn1_get_tag_der (p, der_len, &class, &tag_len, &tag); + if (result != ASN1_SUCCESS) + { + warn(); + return result; + } + + if (tag != ETYPE_TAG (etype)) + { + warn(); + return ASN1_DER_ERROR; + } + + p += tag_len; + + DECR_LEN(der_len, tag_len); + + if (ber_len) *ber_len += tag_len; + } + + /* indefinite constructed */ + if ((((dflags & DECODE_FLAG_CONSTRUCTED) || class == ASN1_CLASS_STRUCTURED) && ETYPE_IS_STRING(etype)) && + !(dflags & DECODE_FLAG_LEVEL3)) + { + if (der_len == 0) + { + warn(); + result = ASN1_DER_ERROR; + goto cleanup; + } + + if (der_len > 0 && p[0] == 0x80) /* indefinite */ + { + len_len = 1; + DECR_LEN(der_len, len_len); + p += len_len; + + if (ber_len) *ber_len += len_len; + + /* decode the available octet strings */ + do + { + unsigned tmp_len; + unsigned flags = DECODE_FLAG_HAVE_TAG; + + if (dflags & DECODE_FLAG_LEVEL1) + flags |= DECODE_FLAG_LEVEL2; + else if (dflags & DECODE_FLAG_LEVEL2) + flags |= DECODE_FLAG_LEVEL3; + else + flags |= DECODE_FLAG_LEVEL1; + + result = _asn1_decode_simple_ber(etype, p, der_len, &out, &out_len, &tmp_len, + flags); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + p += tmp_len; + DECR_LEN(der_len, tmp_len); + + if (ber_len) *ber_len += tmp_len; + + DECR_LEN(der_len, 2); /* we need the EOC */ + + result = append(&total, &total_size, out, out_len); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + free(out); + out = NULL; + + if (p[0] == 0 && p[1] == 0) /* EOC */ + { + if (ber_len) *ber_len += 2; + break; + } + + /* no EOC */ + der_len += 2; + + if (der_len == 2) + { + warn(); + result = ASN1_DER_ERROR; + goto cleanup; + } + } + while(1); + } + else /* constructed */ + { + long const_len; + + result = asn1_get_length_ber(p, der_len, &len_len); + if (result < 0) + { + warn(); + result = ASN1_DER_ERROR; + goto cleanup; + } + + DECR_LEN(der_len, len_len); + p += len_len; + + const_len = result; + + if (ber_len) *ber_len += len_len; + + /* decode the available octet strings */ + while(const_len > 0) + { + unsigned tmp_len; + unsigned flags = DECODE_FLAG_HAVE_TAG; + + if (dflags & DECODE_FLAG_LEVEL1) + flags |= DECODE_FLAG_LEVEL2; + else if (dflags & DECODE_FLAG_LEVEL2) + flags |= DECODE_FLAG_LEVEL3; + else + flags |= DECODE_FLAG_LEVEL1; + + result = _asn1_decode_simple_ber(etype, p, der_len, &out, &out_len, &tmp_len, + flags); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + p += tmp_len; + DECR_LEN(der_len, tmp_len); + DECR_LEN(const_len, tmp_len); + + if (ber_len) *ber_len += tmp_len; + + result = append(&total, &total_size, out, out_len); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + free(out); + out = NULL; + } + } + } + else if (class == ETYPE_CLASS(etype)) + { + if (ber_len) + { + result = asn1_get_length_der (p, der_len, &len_len); + if (result < 0) + { + warn(); + result = ASN1_DER_ERROR; + goto cleanup; + } + *ber_len += result + len_len; + } + + /* non-string values are decoded as DER */ + result = _asn1_decode_simple_der(etype, der, _der_len, &cout, &out_len, dflags); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + + result = append(&total, &total_size, cout, out_len); + if (result != ASN1_SUCCESS) + { + warn(); + goto cleanup; + } + } + else + { + warn(); + result = ASN1_DER_ERROR; + goto cleanup; + } + + *str = total; + *str_len = total_size; + + return ASN1_SUCCESS; +cleanup: + free(out); + free(total); + return result; +} + +/** + * asn1_decode_simple_ber: + * @etype: The type of the string to be encoded (ASN1_ETYPE_) + * @der: the encoded string + * @_der_len: the bytes of the encoded string + * @str: a pointer to the data + * @str_len: the length of the data + * @ber_len: the total length occupied by BER (may be %NULL) + * + * Decodes a BER encoded type. The output is an allocated value + * of the data. This decodes BER STRINGS only. Other types are + * decoded as DER. + * + * Returns: %ASN1_SUCCESS if successful or an error value. + **/ +int +asn1_decode_simple_ber (unsigned int etype, const unsigned char *der, + unsigned int _der_len, unsigned char **str, + unsigned int *str_len, unsigned int *ber_len) +{ + return _asn1_decode_simple_ber(etype, der, _der_len, str, str_len, ber_len, DECODE_FLAG_HAVE_TAG); +} |