asn1_lib.c

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/* 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/asn1_mac.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 int asn1_get_length(const unsigned char **pp, long *rl, long max);
static void asn1_put_length(unsigned char **pp, int length);
 
int ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
                    int *pclass, long omax)
{
    int i, ret;
    long l;
    const unsigned char *p = *pp;
    int tag, xclass;
    long max = omax;
 
    if (!max)
        goto err;
    ret = (*p & V_ASN1_CONSTRUCTED);
    xclass = (*p & V_ASN1_PRIVATE);
    i = *p & V_ASN1_PRIMITIVE_TAG;
    if (i == V_ASN1_PRIMITIVE_TAG) { /* high-tag */
        p++;
        if (--max == 0)
            goto err;
        l = 0;
        while (*p & 0x80) {
            l <<= 7L;
            l |= *(p++) & 0x7f;
            if (--max == 0)
                goto err;
            if (l > (INT_MAX >> 7L))
                goto err;
        }
        l <<= 7L;
        l |= *(p++) & 0x7f;
        tag = (int)l;
        if (--max == 0)
            goto err;
    } else {
        tag = i;
        p++;
        if (--max == 0)
            goto err;
    }
 
    /* To avoid ambiguity with V_ASN1_NEG, impose a limit on universal tags. */
    if (xclass == V_ASN1_UNIVERSAL && tag > V_ASN1_MAX_UNIVERSAL)
        goto err;
 
    *ptag = tag;
    *pclass = xclass;
    if (!asn1_get_length(&p, plength, max))
        goto err;
 
    if (*plength > (omax - (p - *pp))) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG);
        return 0x80;
    }
    *pp = p;
    return ret;
 err:
    OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
    return 0x80;
}
 
static int asn1_get_length(const unsigned char **pp, long *rl, long max)
{
    const unsigned char *p = *pp;
    unsigned long ret = 0;
    unsigned long i;
 
    if (max-- < 1) {
        return 0;
    }
    if (*p == 0x80) {
        /* We do not support BER indefinite-length encoding. */
        return 0;
    }
    i = *p & 0x7f;
    if (*(p++) & 0x80) {
        if (i > sizeof(ret) || max < (long)i)
            return 0;
        while (i-- > 0) {
            ret <<= 8L;
            ret |= *(p++);
        }
    } else {
        ret = i;
    }
    /*
     * Bound the length to comfortably fit in an int. Lengths in this module
     * often switch between int and long without overflow checks.
     */
    if (ret > INT_MAX / 2)
        return 0;
    *pp = p;
    *rl = (long)ret;
    return 1;
}
 
/*
 * 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;
}