| /* |
| * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the OpenSSL license (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #include <openssl/asn1.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include <openssl/bytestring.h> |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| |
| #include "../internal.h" |
| |
| |
| ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x) { |
| return ASN1_STRING_dup(x); |
| } |
| |
| int ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y) { |
| // Compare signs. |
| int neg = x->type & V_ASN1_NEG; |
| if (neg != (y->type & V_ASN1_NEG)) { |
| return neg ? -1 : 1; |
| } |
| |
| int ret = ASN1_STRING_cmp(x, y); |
| if (neg) { |
| // This could be |-ret|, but |ASN1_STRING_cmp| is not forbidden from |
| // returning |INT_MIN|. |
| if (ret < 0) { |
| return 1; |
| } else if (ret > 0) { |
| return -1; |
| } else { |
| return 0; |
| } |
| } |
| |
| return ret; |
| } |
| |
| // negate_twos_complement negates |len| bytes from |buf| in-place, interpreted |
| // as a signed, big-endian two's complement value. |
| static void negate_twos_complement(uint8_t *buf, size_t len) { |
| uint8_t borrow = 0; |
| for (size_t i = len - 1; i < len; i--) { |
| uint8_t t = buf[i]; |
| buf[i] = 0u - borrow - t; |
| borrow |= t != 0; |
| } |
| } |
| |
| static int is_all_zeros(const uint8_t *in, size_t len) { |
| for (size_t i = 0; i < len; i++) { |
| if (in[i] != 0) { |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |
| int i2c_ASN1_INTEGER(const ASN1_INTEGER *in, unsigned char **outp) { |
| if (in == NULL) { |
| return 0; |
| } |
| |
| // |ASN1_INTEGER|s should be represented minimally, but it is possible to |
| // construct invalid ones. Skip leading zeros so this does not produce an |
| // invalid encoding or break invariants. |
| CBS cbs; |
| CBS_init(&cbs, in->data, in->length); |
| while (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0) { |
| CBS_skip(&cbs, 1); |
| } |
| |
| int is_negative = (in->type & V_ASN1_NEG) != 0; |
| size_t pad; |
| CBS copy = cbs; |
| uint8_t msb; |
| if (!CBS_get_u8(©, &msb)) { |
| // Zero is represented as a single byte. |
| is_negative = 0; |
| pad = 1; |
| } else if (is_negative) { |
| // 0x80...01 through 0xff...ff have a two's complement of 0x7f...ff |
| // through 0x00...01 and need an extra byte to be negative. |
| // 0x01...00 through 0x80...00 have a two's complement of 0xfe...ff |
| // through 0x80...00 and can be negated as-is. |
| pad = msb > 0x80 || |
| (msb == 0x80 && !is_all_zeros(CBS_data(©), CBS_len(©))); |
| } else { |
| // If the high bit is set, the signed representation needs an extra |
| // byte to be positive. |
| pad = (msb & 0x80) != 0; |
| } |
| |
| if (CBS_len(&cbs) > INT_MAX - pad) { |
| OPENSSL_PUT_ERROR(ASN1, ERR_R_OVERFLOW); |
| return 0; |
| } |
| int len = (int)(pad + CBS_len(&cbs)); |
| assert(len > 0); |
| if (outp == NULL) { |
| return len; |
| } |
| |
| if (pad) { |
| (*outp)[0] = 0; |
| } |
| OPENSSL_memcpy(*outp + pad, CBS_data(&cbs), CBS_len(&cbs)); |
| if (is_negative) { |
| negate_twos_complement(*outp, len); |
| assert((*outp)[0] >= 0x80); |
| } else { |
| assert((*outp)[0] < 0x80); |
| } |
| *outp += len; |
| return len; |
| } |
| |
| ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **out, const unsigned char **inp, |
| long len) { |
| // This function can handle lengths up to INT_MAX - 1, but the rest of the |
| // legacy ASN.1 code mixes integer types, so avoid exposing it to |
| // ASN1_INTEGERS with larger lengths. |
| if (len < 0 || len > INT_MAX / 2) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG); |
| return NULL; |
| } |
| |
| CBS cbs; |
| CBS_init(&cbs, *inp, (size_t)len); |
| int is_negative; |
| if (!CBS_is_valid_asn1_integer(&cbs, &is_negative)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
| return NULL; |
| } |
| |
| ASN1_INTEGER *ret = NULL; |
| if (out == NULL || *out == NULL) { |
| ret = ASN1_INTEGER_new(); |
| if (ret == NULL) { |
| return NULL; |
| } |
| } else { |
| ret = *out; |
| } |
| |
| // Convert to |ASN1_INTEGER|'s sign-and-magnitude representation. First, |
| // determine the size needed for a minimal result. |
| if (is_negative) { |
| // 0xff00...01 through 0xff7f..ff have a two's complement of 0x00ff...ff |
| // through 0x000100...001 and need one leading zero removed. 0x8000...00 |
| // through 0xff00...00 have a two's complement of 0x8000...00 through |
| // 0x0100...00 and will be minimally-encoded as-is. |
| if (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0xff && |
| !is_all_zeros(CBS_data(&cbs) + 1, CBS_len(&cbs) - 1)) { |
| CBS_skip(&cbs, 1); |
| } |
| } else { |
| // Remove the leading zero byte, if any. |
| if (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0x00) { |
| CBS_skip(&cbs, 1); |
| } |
| } |
| |
| if (!ASN1_STRING_set(ret, CBS_data(&cbs), CBS_len(&cbs))) { |
| goto err; |
| } |
| |
| if (is_negative) { |
| ret->type = V_ASN1_NEG_INTEGER; |
| negate_twos_complement(ret->data, ret->length); |
| } else { |
| ret->type = V_ASN1_INTEGER; |
| } |
| |
| // The value should be minimally-encoded. |
| assert(ret->length == 0 || ret->data[0] != 0); |
| // Zero is not negative. |
| assert(!is_negative || ret->length > 0); |
| |
| *inp += len; |
| if (out != NULL) { |
| *out = ret; |
| } |
| return ret; |
| |
| err: |
| if (ret != NULL && (out == NULL || *out != ret)) { |
| ASN1_INTEGER_free(ret); |
| } |
| return NULL; |
| } |
| |
| int ASN1_INTEGER_set_int64(ASN1_INTEGER *a, int64_t v) { |
| if (v >= 0) { |
| return ASN1_INTEGER_set_uint64(a, (uint64_t)v); |
| } |
| |
| if (!ASN1_INTEGER_set_uint64(a, 0 - (uint64_t)v)) { |
| return 0; |
| } |
| |
| a->type = V_ASN1_NEG_INTEGER; |
| return 1; |
| } |
| |
| int ASN1_ENUMERATED_set_int64(ASN1_ENUMERATED *a, int64_t v) { |
| if (v >= 0) { |
| return ASN1_ENUMERATED_set_uint64(a, (uint64_t)v); |
| } |
| |
| if (!ASN1_ENUMERATED_set_uint64(a, 0 - (uint64_t)v)) { |
| return 0; |
| } |
| |
| a->type = V_ASN1_NEG_ENUMERATED; |
| return 1; |
| } |
| |
| int ASN1_INTEGER_set(ASN1_INTEGER *a, long v) { |
| static_assert(sizeof(long) <= sizeof(int64_t), "long fits in int64_t"); |
| return ASN1_INTEGER_set_int64(a, v); |
| } |
| |
| int ASN1_ENUMERATED_set(ASN1_ENUMERATED *a, long v) { |
| static_assert(sizeof(long) <= sizeof(int64_t), "long fits in int64_t"); |
| return ASN1_ENUMERATED_set_int64(a, v); |
| } |
| |
| static int asn1_string_set_uint64(ASN1_STRING *out, uint64_t v, int type) { |
| uint8_t buf[sizeof(uint64_t)]; |
| CRYPTO_store_u64_be(buf, v); |
| size_t leading_zeros; |
| for (leading_zeros = 0; leading_zeros < sizeof(buf); leading_zeros++) { |
| if (buf[leading_zeros] != 0) { |
| break; |
| } |
| } |
| |
| if (!ASN1_STRING_set(out, buf + leading_zeros, sizeof(buf) - leading_zeros)) { |
| return 0; |
| } |
| out->type = type; |
| return 1; |
| } |
| |
| int ASN1_INTEGER_set_uint64(ASN1_INTEGER *out, uint64_t v) { |
| return asn1_string_set_uint64(out, v, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_ENUMERATED_set_uint64(ASN1_ENUMERATED *out, uint64_t v) { |
| return asn1_string_set_uint64(out, v, V_ASN1_ENUMERATED); |
| } |
| |
| static int asn1_string_get_abs_uint64(uint64_t *out, const ASN1_STRING *a, |
| int type) { |
| if ((a->type & ~V_ASN1_NEG) != type) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_INTEGER_TYPE); |
| return 0; |
| } |
| uint8_t buf[sizeof(uint64_t)] = {0}; |
| if (a->length > (int)sizeof(buf)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
| return 0; |
| } |
| OPENSSL_memcpy(buf + sizeof(buf) - a->length, a->data, a->length); |
| *out = CRYPTO_load_u64_be(buf); |
| return 1; |
| } |
| |
| static int asn1_string_get_uint64(uint64_t *out, const ASN1_STRING *a, |
| int type) { |
| if (!asn1_string_get_abs_uint64(out, a, type)) { |
| return 0; |
| } |
| if (a->type & V_ASN1_NEG) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
| return 0; |
| } |
| return 1; |
| } |
| |
| int ASN1_INTEGER_get_uint64(uint64_t *out, const ASN1_INTEGER *a) { |
| return asn1_string_get_uint64(out, a, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_ENUMERATED_get_uint64(uint64_t *out, const ASN1_ENUMERATED *a) { |
| return asn1_string_get_uint64(out, a, V_ASN1_ENUMERATED); |
| } |
| |
| static int asn1_string_get_int64(int64_t *out, const ASN1_STRING *a, int type) { |
| uint64_t v; |
| if (!asn1_string_get_abs_uint64(&v, a, type)) { |
| return 0; |
| } |
| int64_t i64; |
| int fits_in_i64; |
| // Check |v != 0| to handle manually-constructed negative zeros. |
| if ((a->type & V_ASN1_NEG) && v != 0) { |
| i64 = (int64_t)(0u - v); |
| fits_in_i64 = i64 < 0; |
| } else { |
| i64 = (int64_t)v; |
| fits_in_i64 = i64 >= 0; |
| } |
| if (!fits_in_i64) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
| return 0; |
| } |
| *out = i64; |
| return 1; |
| } |
| |
| int ASN1_INTEGER_get_int64(int64_t *out, const ASN1_INTEGER *a) { |
| return asn1_string_get_int64(out, a, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_ENUMERATED_get_int64(int64_t *out, const ASN1_ENUMERATED *a) { |
| return asn1_string_get_int64(out, a, V_ASN1_ENUMERATED); |
| } |
| |
| static long asn1_string_get_long(const ASN1_STRING *a, int type) { |
| if (a == NULL) { |
| return 0; |
| } |
| |
| int64_t v; |
| if (!asn1_string_get_int64(&v, a, type) || // |
| v < LONG_MIN || v > LONG_MAX) { |
| // This function's return value does not distinguish overflow from -1. |
| ERR_clear_error(); |
| return -1; |
| } |
| |
| return (long)v; |
| } |
| |
| long ASN1_INTEGER_get(const ASN1_INTEGER *a) { |
| return asn1_string_get_long(a, V_ASN1_INTEGER); |
| } |
| |
| long ASN1_ENUMERATED_get(const ASN1_ENUMERATED *a) { |
| return asn1_string_get_long(a, V_ASN1_ENUMERATED); |
| } |
| |
| static ASN1_STRING *bn_to_asn1_string(const BIGNUM *bn, ASN1_STRING *ai, |
| int type) { |
| ASN1_INTEGER *ret; |
| if (ai == NULL) { |
| ret = ASN1_STRING_type_new(type); |
| } else { |
| ret = ai; |
| } |
| int len; |
| if (ret == NULL) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| |
| if (BN_is_negative(bn) && !BN_is_zero(bn)) { |
| ret->type = type | V_ASN1_NEG; |
| } else { |
| ret->type = type; |
| } |
| |
| len = BN_num_bytes(bn); |
| if (!ASN1_STRING_set(ret, NULL, len) || |
| !BN_bn2bin_padded(ret->data, len, bn)) { |
| goto err; |
| } |
| return ret; |
| |
| err: |
| if (ret != ai) { |
| ASN1_STRING_free(ret); |
| } |
| return NULL; |
| } |
| |
| ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai) { |
| return bn_to_asn1_string(bn, ai, V_ASN1_INTEGER); |
| } |
| |
| ASN1_ENUMERATED *BN_to_ASN1_ENUMERATED(const BIGNUM *bn, ASN1_ENUMERATED *ai) { |
| return bn_to_asn1_string(bn, ai, V_ASN1_ENUMERATED); |
| } |
| |
| static BIGNUM *asn1_string_to_bn(const ASN1_STRING *ai, BIGNUM *bn, int type) { |
| if ((ai->type & ~V_ASN1_NEG) != type) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_INTEGER_TYPE); |
| return NULL; |
| } |
| |
| BIGNUM *ret; |
| if ((ret = BN_bin2bn(ai->data, ai->length, bn)) == NULL) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BN_LIB); |
| } else if (ai->type & V_ASN1_NEG) { |
| BN_set_negative(ret, 1); |
| } |
| return ret; |
| } |
| |
| BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn) { |
| return asn1_string_to_bn(ai, bn, V_ASN1_INTEGER); |
| } |
| |
| BIGNUM *ASN1_ENUMERATED_to_BN(const ASN1_ENUMERATED *ai, BIGNUM *bn) { |
| return asn1_string_to_bn(ai, bn, V_ASN1_ENUMERATED); |
| } |
