| /* |
| * Copyright 1995-2017 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 <stdio.h> |
| #include "internal/cryptlib.h" |
| #include "internal/numbers.h" |
| #include <limits.h> |
| #include <openssl/asn1.h> |
| #include <openssl/bn.h> |
| #include "asn1_locl.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) |
| { |
| int neg, ret; |
| /* Compare signs */ |
| neg = x->type & V_ASN1_NEG; |
| if (neg != (y->type & V_ASN1_NEG)) { |
| if (neg) |
| return -1; |
| else |
| return 1; |
| } |
| |
| ret = ASN1_STRING_cmp(x, y); |
| |
| if (neg) |
| return -ret; |
| else |
| return ret; |
| } |
| |
| /*- |
| * This converts a big endian buffer and sign into its content encoding. |
| * This is used for INTEGER and ENUMERATED types. |
| * The internal representation is an ASN1_STRING whose data is a big endian |
| * representation of the value, ignoring the sign. The sign is determined by |
| * the type: if type & V_ASN1_NEG is true it is negative, otherwise positive. |
| * |
| * Positive integers are no problem: they are almost the same as the DER |
| * encoding, except if the first byte is >= 0x80 we need to add a zero pad. |
| * |
| * Negative integers are a bit trickier... |
| * The DER representation of negative integers is in 2s complement form. |
| * The internal form is converted by complementing each octet and finally |
| * adding one to the result. This can be done less messily with a little trick. |
| * If the internal form has trailing zeroes then they will become FF by the |
| * complement and 0 by the add one (due to carry) so just copy as many trailing |
| * zeros to the destination as there are in the source. The carry will add one |
| * to the last none zero octet: so complement this octet and add one and finally |
| * complement any left over until you get to the start of the string. |
| * |
| * Padding is a little trickier too. If the first bytes is > 0x80 then we pad |
| * with 0xff. However if the first byte is 0x80 and one of the following bytes |
| * is non-zero we pad with 0xff. The reason for this distinction is that 0x80 |
| * followed by optional zeros isn't padded. |
| */ |
| |
| /* |
| * If |pad| is zero, the operation is effectively reduced to memcpy, |
| * and if |pad| is 0xff, then it performs two's complement, ~dst + 1. |
| * Note that in latter case sequence of zeros yields itself, and so |
| * does 0x80 followed by any number of zeros. These properties are |
| * used elsewhere below... |
| */ |
| static void twos_complement(unsigned char *dst, const unsigned char *src, |
| size_t len, unsigned char pad) |
| { |
| unsigned int carry = pad & 1; |
| |
| /* Begin at the end of the encoding */ |
| dst += len; |
| src += len; |
| /* two's complement value: ~value + 1 */ |
| while (len-- != 0) { |
| *(--dst) = (unsigned char)(carry += *(--src) ^ pad); |
| carry >>= 8; |
| } |
| } |
| |
| static size_t i2c_ibuf(const unsigned char *b, size_t blen, int neg, |
| unsigned char **pp) |
| { |
| unsigned int pad = 0; |
| size_t ret, i; |
| unsigned char *p, pb = 0; |
| |
| if (b != NULL && blen) { |
| ret = blen; |
| i = b[0]; |
| if (!neg && (i > 127)) { |
| pad = 1; |
| pb = 0; |
| } else if (neg) { |
| pb = 0xFF; |
| if (i > 128) { |
| pad = 1; |
| } else if (i == 128) { |
| /* |
| * Special case [of minimal negative for given length]: |
| * if any other bytes non zero we pad, otherwise we don't. |
| */ |
| for (pad = 0, i = 1; i < blen; i++) |
| pad |= b[i]; |
| pb = pad != 0 ? 0xffU : 0; |
| pad = pb & 1; |
| } |
| } |
| ret += pad; |
| } else { |
| ret = 1; |
| blen = 0; /* reduce '(b == NULL || blen == 0)' to '(blen == 0)' */ |
| } |
| |
| if (pp == NULL || (p = *pp) == NULL) |
| return ret; |
| |
| /* |
| * This magically handles all corner cases, such as '(b == NULL || |
| * blen == 0)', non-negative value, "negative" zero, 0x80 followed |
| * by any number of zeros... |
| */ |
| *p = pb; |
| p += pad; /* yes, p[0] can be written twice, but it's little |
| * price to pay for eliminated branches */ |
| twos_complement(p, b, blen, pb); |
| |
| *pp += ret; |
| return ret; |
| } |
| |
| /* |
| * convert content octets into a big endian buffer. Returns the length |
| * of buffer or 0 on error: for malformed INTEGER. If output buffer is |
| * NULL just return length. |
| */ |
| |
| static size_t c2i_ibuf(unsigned char *b, int *pneg, |
| const unsigned char *p, size_t plen) |
| { |
| int neg, pad; |
| /* Zero content length is illegal */ |
| if (plen == 0) { |
| ASN1err(ASN1_F_C2I_IBUF, ASN1_R_ILLEGAL_ZERO_CONTENT); |
| return 0; |
| } |
| neg = p[0] & 0x80; |
| if (pneg) |
| *pneg = neg; |
| /* Handle common case where length is 1 octet separately */ |
| if (plen == 1) { |
| if (b != NULL) { |
| if (neg) |
| b[0] = (p[0] ^ 0xFF) + 1; |
| else |
| b[0] = p[0]; |
| } |
| return 1; |
| } |
| |
| pad = 0; |
| if (p[0] == 0) { |
| pad = 1; |
| } else if (p[0] == 0xFF) { |
| size_t i; |
| |
| /* |
| * Special case [of "one less minimal negative" for given length]: |
| * if any other bytes non zero it was padded, otherwise not. |
| */ |
| for (pad = 0, i = 1; i < plen; i++) |
| pad |= p[i]; |
| pad = pad != 0 ? 1 : 0; |
| } |
| /* reject illegal padding: first two octets MSB can't match */ |
| if (pad && (neg == (p[1] & 0x80))) { |
| ASN1err(ASN1_F_C2I_IBUF, ASN1_R_ILLEGAL_PADDING); |
| return 0; |
| } |
| |
| /* skip over pad */ |
| p += pad; |
| plen -= pad; |
| |
| if (b != NULL) |
| twos_complement(b, p, plen, neg ? 0xffU : 0); |
| |
| return plen; |
| } |
| |
| int i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp) |
| { |
| return i2c_ibuf(a->data, a->length, a->type & V_ASN1_NEG, pp); |
| } |
| |
| /* Convert big endian buffer into uint64_t, return 0 on error */ |
| static int asn1_get_uint64(uint64_t *pr, const unsigned char *b, size_t blen) |
| { |
| size_t i; |
| uint64_t r; |
| |
| if (blen > sizeof(*pr)) { |
| ASN1err(ASN1_F_ASN1_GET_UINT64, ASN1_R_TOO_LARGE); |
| return 0; |
| } |
| if (b == NULL) |
| return 0; |
| for (r = 0, i = 0; i < blen; i++) { |
| r <<= 8; |
| r |= b[i]; |
| } |
| *pr = r; |
| return 1; |
| } |
| |
| /* |
| * Write uint64_t to big endian buffer and return offset to first |
| * written octet. In other words it returns offset in range from 0 |
| * to 7, with 0 denoting 8 written octets and 7 - one. |
| */ |
| static size_t asn1_put_uint64(unsigned char b[sizeof(uint64_t)], uint64_t r) |
| { |
| size_t off = sizeof(uint64_t); |
| |
| do { |
| b[--off] = (unsigned char)r; |
| } while (r >>= 8); |
| |
| return off; |
| } |
| |
| /* |
| * Absolute value of INT64_MIN: we can't just use -INT64_MIN as gcc produces |
| * overflow warnings. |
| */ |
| #define ABS_INT64_MIN ((uint64_t)INT64_MAX + (-(INT64_MIN + INT64_MAX))) |
| |
| /* signed version of asn1_get_uint64 */ |
| static int asn1_get_int64(int64_t *pr, const unsigned char *b, size_t blen, |
| int neg) |
| { |
| uint64_t r; |
| if (asn1_get_uint64(&r, b, blen) == 0) |
| return 0; |
| if (neg) { |
| if (r <= INT64_MAX) { |
| /* Most significant bit is guaranteed to be clear, negation |
| * is guaranteed to be meaningful in platform-neutral sense. */ |
| *pr = -(int64_t)r; |
| } else if (r == ABS_INT64_MIN) { |
| /* This never happens if INT64_MAX == ABS_INT64_MIN, e.g. |
| * on ones'-complement system. */ |
| *pr = (int64_t)(0 - r); |
| } else { |
| ASN1err(ASN1_F_ASN1_GET_INT64, ASN1_R_TOO_SMALL); |
| return 0; |
| } |
| } else { |
| if (r <= INT64_MAX) { |
| *pr = (int64_t)r; |
| } else { |
| ASN1err(ASN1_F_ASN1_GET_INT64, ASN1_R_TOO_LARGE); |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |
| /* Convert ASN1 INTEGER content octets to ASN1_INTEGER structure */ |
| ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp, |
| long len) |
| { |
| ASN1_INTEGER *ret = NULL; |
| size_t r; |
| int neg; |
| |
| r = c2i_ibuf(NULL, NULL, *pp, len); |
| |
| if (r == 0) |
| return NULL; |
| |
| if ((a == NULL) || ((*a) == NULL)) { |
| ret = ASN1_INTEGER_new(); |
| if (ret == NULL) |
| return NULL; |
| ret->type = V_ASN1_INTEGER; |
| } else |
| ret = *a; |
| |
| if (ASN1_STRING_set(ret, NULL, r) == 0) |
| goto err; |
| |
| c2i_ibuf(ret->data, &neg, *pp, len); |
| |
| if (neg) |
| ret->type |= V_ASN1_NEG; |
| |
| *pp += len; |
| if (a != NULL) |
| (*a) = ret; |
| return ret; |
| err: |
| ASN1err(ASN1_F_C2I_ASN1_INTEGER, ERR_R_MALLOC_FAILURE); |
| if ((a == NULL) || (*a != ret)) |
| ASN1_INTEGER_free(ret); |
| return NULL; |
| } |
| |
| static int asn1_string_get_int64(int64_t *pr, const ASN1_STRING *a, int itype) |
| { |
| if (a == NULL) { |
| ASN1err(ASN1_F_ASN1_STRING_GET_INT64, ERR_R_PASSED_NULL_PARAMETER); |
| return 0; |
| } |
| if ((a->type & ~V_ASN1_NEG) != itype) { |
| ASN1err(ASN1_F_ASN1_STRING_GET_INT64, ASN1_R_WRONG_INTEGER_TYPE); |
| return 0; |
| } |
| return asn1_get_int64(pr, a->data, a->length, a->type & V_ASN1_NEG); |
| } |
| |
| static int asn1_string_set_int64(ASN1_STRING *a, int64_t r, int itype) |
| { |
| unsigned char tbuf[sizeof(r)]; |
| size_t off; |
| |
| a->type = itype; |
| if (r < 0) { |
| /* Most obvious '-r' triggers undefined behaviour for most |
| * common INT64_MIN. Even though below '0 - (uint64_t)r' can |
| * appear two's-complement centric, it does produce correct/ |
| * expected result even on one's-complement. This is because |
| * cast to unsigned has to change bit pattern... */ |
| off = asn1_put_uint64(tbuf, 0 - (uint64_t)r); |
| a->type |= V_ASN1_NEG; |
| } else { |
| off = asn1_put_uint64(tbuf, r); |
| a->type &= ~V_ASN1_NEG; |
| } |
| return ASN1_STRING_set(a, tbuf + off, sizeof(tbuf) - off); |
| } |
| |
| static int asn1_string_get_uint64(uint64_t *pr, const ASN1_STRING *a, |
| int itype) |
| { |
| if (a == NULL) { |
| ASN1err(ASN1_F_ASN1_STRING_GET_UINT64, ERR_R_PASSED_NULL_PARAMETER); |
| return 0; |
| } |
| if ((a->type & ~V_ASN1_NEG) != itype) { |
| ASN1err(ASN1_F_ASN1_STRING_GET_UINT64, ASN1_R_WRONG_INTEGER_TYPE); |
| return 0; |
| } |
| if (a->type & V_ASN1_NEG) { |
| ASN1err(ASN1_F_ASN1_STRING_GET_UINT64, ASN1_R_ILLEGAL_NEGATIVE_VALUE); |
| return 0; |
| } |
| return asn1_get_uint64(pr, a->data, a->length); |
| } |
| |
| static int asn1_string_set_uint64(ASN1_STRING *a, uint64_t r, int itype) |
| { |
| unsigned char tbuf[sizeof(r)]; |
| size_t off; |
| |
| a->type = itype; |
| off = asn1_put_uint64(tbuf, r); |
| return ASN1_STRING_set(a, tbuf + off, sizeof(tbuf) - off); |
| } |
| |
| /* |
| * This is a version of d2i_ASN1_INTEGER that ignores the sign bit of ASN1 |
| * integers: some broken software can encode a positive INTEGER with its MSB |
| * set as negative (it doesn't add a padding zero). |
| */ |
| |
| ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp, |
| long length) |
| { |
| ASN1_INTEGER *ret = NULL; |
| const unsigned char *p; |
| unsigned char *s; |
| long len; |
| int inf, tag, xclass; |
| int i; |
| |
| if ((a == NULL) || ((*a) == NULL)) { |
| if ((ret = ASN1_INTEGER_new()) == NULL) |
| return NULL; |
| ret->type = V_ASN1_INTEGER; |
| } else |
| ret = (*a); |
| |
| p = *pp; |
| inf = ASN1_get_object(&p, &len, &tag, &xclass, length); |
| if (inf & 0x80) { |
| i = ASN1_R_BAD_OBJECT_HEADER; |
| goto err; |
| } |
| |
| if (tag != V_ASN1_INTEGER) { |
| i = ASN1_R_EXPECTING_AN_INTEGER; |
| goto err; |
| } |
| |
| /* |
| * We must OPENSSL_malloc stuff, even for 0 bytes otherwise it signifies |
| * a missing NULL parameter. |
| */ |
| s = OPENSSL_malloc((int)len + 1); |
| if (s == NULL) { |
| i = ERR_R_MALLOC_FAILURE; |
| goto err; |
| } |
| ret->type = V_ASN1_INTEGER; |
| if (len) { |
| if ((*p == 0) && (len != 1)) { |
| p++; |
| len--; |
| } |
| memcpy(s, p, (int)len); |
| p += len; |
| } |
| |
| OPENSSL_free(ret->data); |
| ret->data = s; |
| ret->length = (int)len; |
| if (a != NULL) |
| (*a) = ret; |
| *pp = p; |
| return ret; |
| err: |
| ASN1err(ASN1_F_D2I_ASN1_UINTEGER, i); |
| if ((a == NULL) || (*a != ret)) |
| ASN1_INTEGER_free(ret); |
| return NULL; |
| } |
| |
| static ASN1_STRING *bn_to_asn1_string(const BIGNUM *bn, ASN1_STRING *ai, |
| int atype) |
| { |
| ASN1_INTEGER *ret; |
| int len; |
| |
| if (ai == NULL) { |
| ret = ASN1_STRING_type_new(atype); |
| } else { |
| ret = ai; |
| ret->type = atype; |
| } |
| |
| if (ret == NULL) { |
| ASN1err(ASN1_F_BN_TO_ASN1_STRING, ERR_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| |
| if (BN_is_negative(bn) && !BN_is_zero(bn)) |
| ret->type |= V_ASN1_NEG_INTEGER; |
| |
| len = BN_num_bytes(bn); |
| |
| if (len == 0) |
| len = 1; |
| |
| if (ASN1_STRING_set(ret, NULL, len) == 0) { |
| ASN1err(ASN1_F_BN_TO_ASN1_STRING, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| /* Correct zero case */ |
| if (BN_is_zero(bn)) |
| ret->data[0] = 0; |
| else |
| len = BN_bn2bin(bn, ret->data); |
| ret->length = len; |
| return ret; |
| err: |
| if (ret != ai) |
| ASN1_INTEGER_free(ret); |
| return NULL; |
| } |
| |
| static BIGNUM *asn1_string_to_bn(const ASN1_INTEGER *ai, BIGNUM *bn, |
| int itype) |
| { |
| BIGNUM *ret; |
| |
| if ((ai->type & ~V_ASN1_NEG) != itype) { |
| ASN1err(ASN1_F_ASN1_STRING_TO_BN, ASN1_R_WRONG_INTEGER_TYPE); |
| return NULL; |
| } |
| |
| ret = BN_bin2bn(ai->data, ai->length, bn); |
| if (ret == NULL) { |
| ASN1err(ASN1_F_ASN1_STRING_TO_BN, ASN1_R_BN_LIB); |
| return NULL; |
| } |
| if (ai->type & V_ASN1_NEG) |
| BN_set_negative(ret, 1); |
| return ret; |
| } |
| |
| int ASN1_INTEGER_get_int64(int64_t *pr, const ASN1_INTEGER *a) |
| { |
| return asn1_string_get_int64(pr, a, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_INTEGER_set_int64(ASN1_INTEGER *a, int64_t r) |
| { |
| return asn1_string_set_int64(a, r, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_INTEGER_get_uint64(uint64_t *pr, const ASN1_INTEGER *a) |
| { |
| return asn1_string_get_uint64(pr, a, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_INTEGER_set_uint64(ASN1_INTEGER *a, uint64_t r) |
| { |
| return asn1_string_set_uint64(a, r, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_INTEGER_set(ASN1_INTEGER *a, long v) |
| { |
| return ASN1_INTEGER_set_int64(a, v); |
| } |
| |
| long ASN1_INTEGER_get(const ASN1_INTEGER *a) |
| { |
| int i; |
| int64_t r; |
| if (a == NULL) |
| return 0; |
| i = ASN1_INTEGER_get_int64(&r, a); |
| if (i == 0) |
| return -1; |
| if (r > LONG_MAX || r < LONG_MIN) |
| return -1; |
| return (long)r; |
| } |
| |
| ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai) |
| { |
| return bn_to_asn1_string(bn, ai, V_ASN1_INTEGER); |
| } |
| |
| BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn) |
| { |
| return asn1_string_to_bn(ai, bn, V_ASN1_INTEGER); |
| } |
| |
| int ASN1_ENUMERATED_get_int64(int64_t *pr, const ASN1_ENUMERATED *a) |
| { |
| return asn1_string_get_int64(pr, a, V_ASN1_ENUMERATED); |
| } |
| |
| int ASN1_ENUMERATED_set_int64(ASN1_ENUMERATED *a, int64_t r) |
| { |
| return asn1_string_set_int64(a, r, V_ASN1_ENUMERATED); |
| } |
| |
| int ASN1_ENUMERATED_set(ASN1_ENUMERATED *a, long v) |
| { |
| return ASN1_ENUMERATED_set_int64(a, v); |
| } |
| |
| long ASN1_ENUMERATED_get(const ASN1_ENUMERATED *a) |
| { |
| int i; |
| int64_t r; |
| if (a == NULL) |
| return 0; |
| if ((a->type & ~V_ASN1_NEG) != V_ASN1_ENUMERATED) |
| return -1; |
| if (a->length > (int)sizeof(long)) |
| return 0xffffffffL; |
| i = ASN1_ENUMERATED_get_int64(&r, a); |
| if (i == 0) |
| return -1; |
| if (r > LONG_MAX || r < LONG_MIN) |
| return -1; |
| return (long)r; |
| } |
| |
| ASN1_ENUMERATED *BN_to_ASN1_ENUMERATED(const BIGNUM *bn, ASN1_ENUMERATED *ai) |
| { |
| return bn_to_asn1_string(bn, ai, V_ASN1_ENUMERATED); |
| } |
| |
| BIGNUM *ASN1_ENUMERATED_to_BN(const ASN1_ENUMERATED *ai, BIGNUM *bn) |
| { |
| return asn1_string_to_bn(ai, bn, V_ASN1_ENUMERATED); |
| } |
| |
| /* Internal functions used by x_int64.c */ |
| int c2i_uint64_int(uint64_t *ret, int *neg, const unsigned char **pp, long len) |
| { |
| unsigned char buf[sizeof(uint64_t)]; |
| size_t buflen; |
| |
| buflen = c2i_ibuf(NULL, NULL, *pp, len); |
| if (buflen == 0) |
| return 0; |
| if (buflen > sizeof(uint64_t)) { |
| ASN1err(ASN1_F_C2I_UINT64_INT, ASN1_R_TOO_LARGE); |
| return 0; |
| } |
| (void)c2i_ibuf(buf, neg, *pp, len); |
| return asn1_get_uint64(ret, buf, buflen); |
| } |
| |
| int i2c_uint64_int(unsigned char *p, uint64_t r, int neg) |
| { |
| unsigned char buf[sizeof(uint64_t)]; |
| size_t off; |
| |
| off = asn1_put_uint64(buf, r); |
| return i2c_ibuf(buf + off, sizeof(buf) - off, neg, &p); |
| } |
| |
