crypto/asn1/asn1_lib.c

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.] */

#include <openssl/asn1.h>

#include <limits.h>
#include <string.h>

#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/mem.h>

#include "../internal.h"
#include "internal.h"


/* Cross-module errors from crypto/x509/i2d_pr.c. */
OPENSSL_DECLARE_ERROR_REASON(ASN1, UNSUPPORTED_PUBLIC_KEY_TYPE)

/* Cross-module errors from crypto/x509/algorithm.c. */
OPENSSL_DECLARE_ERROR_REASON(ASN1, CONTEXT_NOT_INITIALISED)
OPENSSL_DECLARE_ERROR_REASON(ASN1, DIGEST_AND_KEY_TYPE_NOT_SUPPORTED)
OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_MESSAGE_DIGEST_ALGORITHM)
OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_SIGNATURE_ALGORITHM)
OPENSSL_DECLARE_ERROR_REASON(ASN1, WRONG_PUBLIC_KEY_TYPE)
/*
 * Cross-module errors from crypto/x509/asn1_gen.c. TODO(davidben): Remove
 * these once asn1_gen.c is gone.
 */
OPENSSL_DECLARE_ERROR_REASON(ASN1, DEPTH_EXCEEDED)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_BITSTRING_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_BOOLEAN)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_HEX)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_IMPLICIT_TAG)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_INTEGER)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_NESTED_TAGGING)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_NULL_VALUE)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_OBJECT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_TIME_VALUE)
OPENSSL_DECLARE_ERROR_REASON(ASN1, INTEGER_NOT_ASCII_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, INVALID_MODIFIER)
OPENSSL_DECLARE_ERROR_REASON(ASN1, INVALID_NUMBER)
OPENSSL_DECLARE_ERROR_REASON(ASN1, LIST_ERROR)
OPENSSL_DECLARE_ERROR_REASON(ASN1, MISSING_VALUE)
OPENSSL_DECLARE_ERROR_REASON(ASN1, NOT_ASCII_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, OBJECT_NOT_ASCII_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, SEQUENCE_OR_SET_NEEDS_CONFIG)
OPENSSL_DECLARE_ERROR_REASON(ASN1, TIME_NOT_ASCII_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_FORMAT)
OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_TAG)
OPENSSL_DECLARE_ERROR_REASON(ASN1, UNSUPPORTED_TYPE)

static void asn1_put_length(unsigned char **pp, int length);

int ASN1_get_object(const unsigned char **inp, long *out_len, int *out_tag,
                    int *out_class, long in_len)
{
    if (in_len < 0) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
        return 0x80;
    }

    /* TODO(https://crbug.com/boringssl/354): This should use |CBS_get_asn1| to
     * reject non-minimal lengths, which are only allowed in BER. However,
     * Android sometimes needs allow a non-minimal length in certificate
     * signature fields (see b/18228011). Make this only apply to that field,
     * while requiring DER elsewhere. Better yet, it should be limited to an
     * preprocessing step in that part of Android. */
    unsigned tag;
    size_t header_len;
    int indefinite;
    CBS cbs, body;
    CBS_init(&cbs, *inp, (size_t)in_len);
    if (!CBS_get_any_ber_asn1_element(&cbs, &body, &tag, &header_len,
        /*out_ber_found=*/NULL, &indefinite) ||
        indefinite ||
        !CBS_skip(&body, header_len) ||
        /* Bound the length to comfortably fit in an int. Lengths in this
         * module often switch between int and long without overflow checks. */
        CBS_len(&body) > INT_MAX / 2) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
        return 0x80;
    }

    /* Convert between tag representations. */
    int tag_class = (tag & CBS_ASN1_CLASS_MASK) >> CBS_ASN1_TAG_SHIFT;
    int constructed = (tag & CBS_ASN1_CONSTRUCTED) >> CBS_ASN1_TAG_SHIFT;
    int tag_number = tag & CBS_ASN1_TAG_NUMBER_MASK;

    /* To avoid ambiguity with V_ASN1_NEG, impose a limit on universal tags. */
    if (tag_class == V_ASN1_UNIVERSAL && tag_number > V_ASN1_MAX_UNIVERSAL) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
        return 0x80;
    }

    *inp = CBS_data(&body);
    *out_len = CBS_len(&body);
    *out_tag = tag_number;
    *out_class = tag_class;
    return constructed;
}

/*
 * class 0 is constructed constructed == 2 for indefinite length constructed
 */
void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
                     int xclass)
{
    unsigned char *p = *pp;
    int i, ttag;

    i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
    i |= (xclass & V_ASN1_PRIVATE);
    if (tag < 31)
        *(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
    else {
        *(p++) = i | V_ASN1_PRIMITIVE_TAG;
        for (i = 0, ttag = tag; ttag > 0; i++)
            ttag >>= 7;
        ttag = i;
        while (i-- > 0) {
            p[i] = tag & 0x7f;
            if (i != (ttag - 1))
                p[i] |= 0x80;
            tag >>= 7;
        }
        p += ttag;
    }
    if (constructed == 2)
        *(p++) = 0x80;
    else
        asn1_put_length(&p, length);
    *pp = p;
}

int ASN1_put_eoc(unsigned char **pp)
{
    /* This function is no longer used in the library, but some external code
     * uses it. */
    unsigned char *p = *pp;
    *p++ = 0;
    *p++ = 0;
    *pp = p;
    return 2;
}

static void asn1_put_length(unsigned char **pp, int length)
{
    unsigned char *p = *pp;
    int i, l;
    if (length <= 127)
        *(p++) = (unsigned char)length;
    else {
        l = length;
        for (i = 0; l > 0; i++)
            l >>= 8;
        *(p++) = i | 0x80;
        l = i;
        while (i-- > 0) {
            p[i] = length & 0xff;
            length >>= 8;
        }
        p += l;
    }
    *pp = p;
}

int ASN1_object_size(int constructed, int length, int tag)
{
    int ret = 1;
    if (length < 0)
        return -1;
    if (tag >= 31) {
        while (tag > 0) {
            tag >>= 7;
            ret++;
        }
    }
    if (constructed == 2) {
        ret += 3;
    } else {
        ret++;
        if (length > 127) {
            int tmplen = length;
            while (tmplen > 0) {
                tmplen >>= 8;
                ret++;
            }
        }
    }
    if (ret >= INT_MAX - length)
        return -1;
    return ret + length;
}

int ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str)
{
    if (str == NULL)
        return 0;
    if (!ASN1_STRING_set(dst, str->data, str->length))
        return 0;
    dst->type = str->type;
    dst->flags = str->flags;
    return 1;
}

ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *str)
{
    ASN1_STRING *ret;
    if (!str)
        return NULL;
    ret = ASN1_STRING_new();
    if (!ret)
        return NULL;
    if (!ASN1_STRING_copy(ret, str)) {
        ASN1_STRING_free(ret);
        return NULL;
    }
    return ret;
}

int ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len)
{
    unsigned char *c;
    const char *data = _data;

    if (len < 0) {
        if (data == NULL)
            return (0);
        else
            len = strlen(data);
    }
    if ((str->length <= len) || (str->data == NULL)) {
        c = str->data;
        if (c == NULL)
            str->data = OPENSSL_malloc(len + 1);
        else
            str->data = OPENSSL_realloc(c, len + 1);

        if (str->data == NULL) {
            OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
            str->data = c;
            return (0);
        }
    }
    str->length = len;
    if (data != NULL) {
        OPENSSL_memcpy(str->data, data, len);
        /* an allowance for strings :-) */
        str->data[len] = '\0';
    }
    return (1);
}

void ASN1_STRING_set0(ASN1_STRING *str, void *data, int len)
{
    OPENSSL_free(str->data);
    str->data = data;
    str->length = len;
}

ASN1_STRING *ASN1_STRING_new(void)
{
    return (ASN1_STRING_type_new(V_ASN1_OCTET_STRING));
}

ASN1_STRING *ASN1_STRING_type_new(int type)
{
    ASN1_STRING *ret;

    ret = (ASN1_STRING *)OPENSSL_malloc(sizeof(ASN1_STRING));
    if (ret == NULL) {
        OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
        return (NULL);
    }
    ret->length = 0;
    ret->type = type;
    ret->data = NULL;
    ret->flags = 0;
    return (ret);
}

void ASN1_STRING_free(ASN1_STRING *str)
{
    if (str == NULL)
        return;
    OPENSSL_free(str->data);
    OPENSSL_free(str);
}

int ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b)
{
    /* Capture padding bits and implicit truncation in BIT STRINGs. */
    int a_length = a->length, b_length = b->length;
    uint8_t a_padding = 0, b_padding = 0;
    if (a->type == V_ASN1_BIT_STRING) {
        a_length = asn1_bit_string_length(a, &a_padding);
    }
    if (b->type == V_ASN1_BIT_STRING) {
        b_length = asn1_bit_string_length(b, &b_padding);
    }

    if (a_length < b_length) {
        return -1;
    }
    if (a_length > b_length) {
        return 1;
    }
    /* In a BIT STRING, the number of bits is 8 * length - padding. Invert this
     * comparison so we compare by lengths. */
    if (a_padding > b_padding) {
        return -1;
    }
    if (a_padding < b_padding) {
        return 1;
    }

    int ret = OPENSSL_memcmp(a->data, b->data, a_length);
    if (ret != 0) {
        return ret;
    }

    /* Comparing the type first is more natural, but this matches OpenSSL. */
    if (a->type < b->type) {
        return -1;
    }
    if (a->type > b->type) {
        return 1;
    }
    return 0;
}

int ASN1_STRING_length(const ASN1_STRING *str)
{
    return str->length;
}

int ASN1_STRING_type(const ASN1_STRING *str)
{
    return str->type;
}

unsigned char *ASN1_STRING_data(ASN1_STRING *str)
{
    return str->data;
}

const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *str)
{
    return str->data;
}