--- /dev/null
+/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
+ * project 2005.
+ */
+/* ====================================================================
+ * Copyright (c) 2005 The OpenSSL Project. All rights reserved.
+ *
+ * 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 above 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 acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com). */
+
+#include <openssl/rsa.h>
+
+#include <assert.h>
+#include <limits.h>
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/digest.h>
+#include <openssl/err.h>
+#include <openssl/mem.h>
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+
+#include "internal.h"
+#include "../../internal.h"
+
+
+#define RSA_PKCS1_PADDING_SIZE 11
+
+int RSA_padding_add_PKCS1_type_1(uint8_t *to, size_t to_len,
+ const uint8_t *from, size_t from_len) {
+ // See RFC 8017, section 9.2.
+ if (to_len < RSA_PKCS1_PADDING_SIZE) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL);
+ return 0;
+ }
+
+ if (from_len > to_len - RSA_PKCS1_PADDING_SIZE) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
+ return 0;
+ }
+
+ to[0] = 0;
+ to[1] = 1;
+ OPENSSL_memset(to + 2, 0xff, to_len - 3 - from_len);
+ to[to_len - from_len - 1] = 0;
+ OPENSSL_memcpy(to + to_len - from_len, from, from_len);
+ return 1;
+}
+
+int RSA_padding_check_PKCS1_type_1(uint8_t *out, size_t *out_len,
+ size_t max_out, const uint8_t *from,
+ size_t from_len) {
+ // See RFC 8017, section 9.2. This is part of signature verification and thus
+ // does not need to run in constant-time.
+ if (from_len < 2) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_SMALL);
+ return 0;
+ }
+
+ // Check the header.
+ if (from[0] != 0 || from[1] != 1) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_BLOCK_TYPE_IS_NOT_01);
+ return 0;
+ }
+
+ // Scan over padded data, looking for the 00.
+ size_t pad;
+ for (pad = 2 /* header */; pad < from_len; pad++) {
+ if (from[pad] == 0x00) {
+ break;
+ }
+
+ if (from[pad] != 0xff) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_FIXED_HEADER_DECRYPT);
+ return 0;
+ }
+ }
+
+ if (pad == from_len) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_NULL_BEFORE_BLOCK_MISSING);
+ return 0;
+ }
+
+ if (pad < 2 /* header */ + 8) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_PAD_BYTE_COUNT);
+ return 0;
+ }
+
+ // Skip over the 00.
+ pad++;
+
+ if (from_len - pad > max_out) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ return 0;
+ }
+
+ OPENSSL_memcpy(out, from + pad, from_len - pad);
+ *out_len = from_len - pad;
+ return 1;
+}
+
+static int rand_nonzero(uint8_t *out, size_t len) {
+ if (!RAND_bytes(out, len)) {
+ return 0;
+ }
+
+ for (size_t i = 0; i < len; i++) {
+ while (out[i] == 0) {
+ if (!RAND_bytes(out + i, 1)) {
+ return 0;
+ }
+ }
+ }
+
+ return 1;
+}
+
+int RSA_padding_add_PKCS1_type_2(uint8_t *to, size_t to_len,
+ const uint8_t *from, size_t from_len) {
+ // See RFC 8017, section 7.2.1.
+ if (to_len < RSA_PKCS1_PADDING_SIZE) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL);
+ return 0;
+ }
+
+ if (from_len > to_len - RSA_PKCS1_PADDING_SIZE) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ return 0;
+ }
+
+ to[0] = 0;
+ to[1] = 2;
+
+ size_t padding_len = to_len - 3 - from_len;
+ if (!rand_nonzero(to + 2, padding_len)) {
+ return 0;
+ }
+
+ to[2 + padding_len] = 0;
+ OPENSSL_memcpy(to + to_len - from_len, from, from_len);
+ return 1;
+}
+
+int RSA_padding_check_PKCS1_type_2(uint8_t *out, size_t *out_len,
+ size_t max_out, const uint8_t *from,
+ size_t from_len) {
+ if (from_len == 0) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_EMPTY_PUBLIC_KEY);
+ return 0;
+ }
+
+ // PKCS#1 v1.5 decryption. See "PKCS #1 v2.2: RSA Cryptography
+ // Standard", section 7.2.2.
+ if (from_len < RSA_PKCS1_PADDING_SIZE) {
+ // |from| is zero-padded to the size of the RSA modulus, a public value, so
+ // this can be rejected in non-constant time.
+ OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL);
+ return 0;
+ }
+
+ crypto_word_t first_byte_is_zero = constant_time_eq_w(from[0], 0);
+ crypto_word_t second_byte_is_two = constant_time_eq_w(from[1], 2);
+
+ crypto_word_t zero_index = 0, looking_for_index = CONSTTIME_TRUE_W;
+ for (size_t i = 2; i < from_len; i++) {
+ crypto_word_t equals0 = constant_time_is_zero_w(from[i]);
+ zero_index =
+ constant_time_select_w(looking_for_index & equals0, i, zero_index);
+ looking_for_index = constant_time_select_w(equals0, 0, looking_for_index);
+ }
+
+ // The input must begin with 00 02.
+ crypto_word_t valid_index = first_byte_is_zero;
+ valid_index &= second_byte_is_two;
+
+ // We must have found the end of PS.
+ valid_index &= ~looking_for_index;
+
+ // PS must be at least 8 bytes long, and it starts two bytes into |from|.
+ valid_index &= constant_time_ge_w(zero_index, 2 + 8);
+
+ // Skip the zero byte.
+ zero_index++;
+
+ // NOTE: Although this logic attempts to be constant time, the API contracts
+ // of this function and |RSA_decrypt| with |RSA_PKCS1_PADDING| make it
+ // impossible to completely avoid Bleichenbacher's attack. Consumers should
+ // use |RSA_PADDING_NONE| and perform the padding check in constant-time
+ // combined with a swap to a random session key or other mitigation.
+ if (!valid_index) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_PKCS_DECODING_ERROR);
+ return 0;
+ }
+
+ const size_t msg_len = from_len - zero_index;
+ if (msg_len > max_out) {
+ // This shouldn't happen because this function is always called with
+ // |max_out| as the key size and |from_len| is bounded by the key size.
+ OPENSSL_PUT_ERROR(RSA, RSA_R_PKCS_DECODING_ERROR);
+ return 0;
+ }
+
+ OPENSSL_memcpy(out, &from[zero_index], msg_len);
+ *out_len = msg_len;
+ return 1;
+}
+
+int RSA_padding_add_none(uint8_t *to, size_t to_len, const uint8_t *from,
+ size_t from_len) {
+ if (from_len > to_len) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ return 0;
+ }
+
+ if (from_len < to_len) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_SMALL);
+ return 0;
+ }
+
+ OPENSSL_memcpy(to, from, from_len);
+ return 1;
+}
+
+static int PKCS1_MGF1(uint8_t *out, size_t len, const uint8_t *seed,
+ size_t seed_len, const EVP_MD *md) {
+ int ret = 0;
+ EVP_MD_CTX ctx;
+ EVP_MD_CTX_init(&ctx);
+
+ size_t md_len = EVP_MD_size(md);
+
+ for (uint32_t i = 0; len > 0; i++) {
+ uint8_t counter[4];
+ counter[0] = (uint8_t)(i >> 24);
+ counter[1] = (uint8_t)(i >> 16);
+ counter[2] = (uint8_t)(i >> 8);
+ counter[3] = (uint8_t)i;
+ if (!EVP_DigestInit_ex(&ctx, md, NULL) ||
+ !EVP_DigestUpdate(&ctx, seed, seed_len) ||
+ !EVP_DigestUpdate(&ctx, counter, sizeof(counter))) {
+ goto err;
+ }
+
+ if (md_len <= len) {
+ if (!EVP_DigestFinal_ex(&ctx, out, NULL)) {
+ goto err;
+ }
+ out += md_len;
+ len -= md_len;
+ } else {
+ uint8_t digest[EVP_MAX_MD_SIZE];
+ if (!EVP_DigestFinal_ex(&ctx, digest, NULL)) {
+ goto err;
+ }
+ OPENSSL_memcpy(out, digest, len);
+ len = 0;
+ }
+ }
+
+ ret = 1;
+
+err:
+ EVP_MD_CTX_cleanup(&ctx);
+ return ret;
+}
+
+int RSA_padding_add_PKCS1_OAEP_mgf1(uint8_t *to, size_t to_len,
+ const uint8_t *from, size_t from_len,
+ const uint8_t *param, size_t param_len,
+ const EVP_MD *md, const EVP_MD *mgf1md) {
+ if (md == NULL) {
+ md = EVP_sha1();
+ }
+ if (mgf1md == NULL) {
+ mgf1md = md;
+ }
+
+ size_t mdlen = EVP_MD_size(md);
+
+ if (to_len < 2 * mdlen + 2) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL);
+ return 0;
+ }
+
+ size_t emlen = to_len - 1;
+ if (from_len > emlen - 2 * mdlen - 1) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ return 0;
+ }
+
+ if (emlen < 2 * mdlen + 1) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL);
+ return 0;
+ }
+
+ to[0] = 0;
+ uint8_t *seed = to + 1;
+ uint8_t *db = to + mdlen + 1;
+
+ if (!EVP_Digest(param, param_len, db, NULL, md, NULL)) {
+ return 0;
+ }
+ OPENSSL_memset(db + mdlen, 0, emlen - from_len - 2 * mdlen - 1);
+ db[emlen - from_len - mdlen - 1] = 0x01;
+ OPENSSL_memcpy(db + emlen - from_len - mdlen, from, from_len);
+ if (!RAND_bytes(seed, mdlen)) {
+ return 0;
+ }
+
+ uint8_t *dbmask = OPENSSL_malloc(emlen - mdlen);
+ if (dbmask == NULL) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+
+ int ret = 0;
+ if (!PKCS1_MGF1(dbmask, emlen - mdlen, seed, mdlen, mgf1md)) {
+ goto out;
+ }
+ for (size_t i = 0; i < emlen - mdlen; i++) {
+ db[i] ^= dbmask[i];
+ }
+
+ uint8_t seedmask[EVP_MAX_MD_SIZE];
+ if (!PKCS1_MGF1(seedmask, mdlen, db, emlen - mdlen, mgf1md)) {
+ goto out;
+ }
+ for (size_t i = 0; i < mdlen; i++) {
+ seed[i] ^= seedmask[i];
+ }
+ ret = 1;
+
+out:
+ OPENSSL_free(dbmask);
+ return ret;
+}
+
+int RSA_padding_check_PKCS1_OAEP_mgf1(uint8_t *out, size_t *out_len,
+ size_t max_out, const uint8_t *from,
+ size_t from_len, const uint8_t *param,
+ size_t param_len, const EVP_MD *md,
+ const EVP_MD *mgf1md) {
+ uint8_t *db = NULL;
+
+ if (md == NULL) {
+ md = EVP_sha1();
+ }
+ if (mgf1md == NULL) {
+ mgf1md = md;
+ }
+
+ size_t mdlen = EVP_MD_size(md);
+
+ // The encoded message is one byte smaller than the modulus to ensure that it
+ // doesn't end up greater than the modulus. Thus there's an extra "+1" here
+ // compared to https://tools.ietf.org/html/rfc2437#section-9.1.1.2.
+ if (from_len < 1 + 2*mdlen + 1) {
+ // 'from_len' is the length of the modulus, i.e. does not depend on the
+ // particular ciphertext.
+ goto decoding_err;
+ }
+
+ size_t dblen = from_len - mdlen - 1;
+ db = OPENSSL_malloc(dblen);
+ if (db == NULL) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ const uint8_t *maskedseed = from + 1;
+ const uint8_t *maskeddb = from + 1 + mdlen;
+
+ uint8_t seed[EVP_MAX_MD_SIZE];
+ if (!PKCS1_MGF1(seed, mdlen, maskeddb, dblen, mgf1md)) {
+ goto err;
+ }
+ for (size_t i = 0; i < mdlen; i++) {
+ seed[i] ^= maskedseed[i];
+ }
+
+ if (!PKCS1_MGF1(db, dblen, seed, mdlen, mgf1md)) {
+ goto err;
+ }
+ for (size_t i = 0; i < dblen; i++) {
+ db[i] ^= maskeddb[i];
+ }
+
+ uint8_t phash[EVP_MAX_MD_SIZE];
+ if (!EVP_Digest(param, param_len, phash, NULL, md, NULL)) {
+ goto err;
+ }
+
+ crypto_word_t bad = ~constant_time_is_zero_w(CRYPTO_memcmp(db, phash, mdlen));
+ bad |= ~constant_time_is_zero_w(from[0]);
+
+ crypto_word_t looking_for_one_byte = CONSTTIME_TRUE_W;
+ size_t one_index = 0;
+ for (size_t i = mdlen; i < dblen; i++) {
+ crypto_word_t equals1 = constant_time_eq_w(db[i], 1);
+ crypto_word_t equals0 = constant_time_eq_w(db[i], 0);
+ one_index =
+ constant_time_select_w(looking_for_one_byte & equals1, i, one_index);
+ looking_for_one_byte =
+ constant_time_select_w(equals1, 0, looking_for_one_byte);
+ bad |= looking_for_one_byte & ~equals0;
+ }
+
+ bad |= looking_for_one_byte;
+
+ if (bad) {
+ goto decoding_err;
+ }
+
+ one_index++;
+ size_t mlen = dblen - one_index;
+ if (max_out < mlen) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ goto err;
+ }
+
+ OPENSSL_memcpy(out, db + one_index, mlen);
+ *out_len = mlen;
+ OPENSSL_free(db);
+ return 1;
+
+decoding_err:
+ // to avoid chosen ciphertext attacks, the error message should not reveal
+ // which kind of decoding error happened
+ OPENSSL_PUT_ERROR(RSA, RSA_R_OAEP_DECODING_ERROR);
+ err:
+ OPENSSL_free(db);
+ return 0;
+}
+
+static const uint8_t kPSSZeroes[] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const uint8_t *mHash,
+ const EVP_MD *Hash, const EVP_MD *mgf1Hash,
+ const uint8_t *EM, int sLen) {
+ int i;
+ int ret = 0;
+ int maskedDBLen, MSBits, emLen;
+ size_t hLen;
+ const uint8_t *H;
+ uint8_t *DB = NULL;
+ EVP_MD_CTX ctx;
+ uint8_t H_[EVP_MAX_MD_SIZE];
+ EVP_MD_CTX_init(&ctx);
+
+ if (mgf1Hash == NULL) {
+ mgf1Hash = Hash;
+ }
+
+ hLen = EVP_MD_size(Hash);
+
+ // Negative sLen has special meanings:
+ // -1 sLen == hLen
+ // -2 salt length is autorecovered from signature
+ // -N reserved
+ if (sLen == -1) {
+ sLen = hLen;
+ } else if (sLen == -2) {
+ sLen = -2;
+ } else if (sLen < -2) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_SLEN_CHECK_FAILED);
+ goto err;
+ }
+
+ MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
+ emLen = RSA_size(rsa);
+ if (EM[0] & (0xFF << MSBits)) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_FIRST_OCTET_INVALID);
+ goto err;
+ }
+ if (MSBits == 0) {
+ EM++;
+ emLen--;
+ }
+ if (emLen < (int)hLen + 2 || emLen < ((int)hLen + sLen + 2)) {
+ // sLen can be small negative
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ goto err;
+ }
+ if (EM[emLen - 1] != 0xbc) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_LAST_OCTET_INVALID);
+ goto err;
+ }
+ maskedDBLen = emLen - hLen - 1;
+ H = EM + maskedDBLen;
+ DB = OPENSSL_malloc(maskedDBLen);
+ if (!DB) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ if (!PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash)) {
+ goto err;
+ }
+ for (i = 0; i < maskedDBLen; i++) {
+ DB[i] ^= EM[i];
+ }
+ if (MSBits) {
+ DB[0] &= 0xFF >> (8 - MSBits);
+ }
+ for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) {
+ ;
+ }
+ if (DB[i++] != 0x1) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_SLEN_RECOVERY_FAILED);
+ goto err;
+ }
+ if (sLen >= 0 && (maskedDBLen - i) != sLen) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_SLEN_CHECK_FAILED);
+ goto err;
+ }
+ if (!EVP_DigestInit_ex(&ctx, Hash, NULL) ||
+ !EVP_DigestUpdate(&ctx, kPSSZeroes, sizeof(kPSSZeroes)) ||
+ !EVP_DigestUpdate(&ctx, mHash, hLen) ||
+ !EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i) ||
+ !EVP_DigestFinal_ex(&ctx, H_, NULL)) {
+ goto err;
+ }
+ if (OPENSSL_memcmp(H_, H, hLen)) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_SIGNATURE);
+ ret = 0;
+ } else {
+ ret = 1;
+ }
+
+err:
+ OPENSSL_free(DB);
+ EVP_MD_CTX_cleanup(&ctx);
+
+ return ret;
+}
+
+int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
+ const unsigned char *mHash,
+ const EVP_MD *Hash, const EVP_MD *mgf1Hash,
+ int sLenRequested) {
+ int ret = 0;
+ size_t maskedDBLen, MSBits, emLen;
+ size_t hLen;
+ unsigned char *H, *salt = NULL, *p;
+
+ if (mgf1Hash == NULL) {
+ mgf1Hash = Hash;
+ }
+
+ hLen = EVP_MD_size(Hash);
+
+ if (BN_is_zero(rsa->n)) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_EMPTY_PUBLIC_KEY);
+ goto err;
+ }
+
+ MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
+ emLen = RSA_size(rsa);
+ if (MSBits == 0) {
+ assert(emLen >= 1);
+ *EM++ = 0;
+ emLen--;
+ }
+
+ if (emLen < hLen + 2) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ goto err;
+ }
+
+ // Negative sLenRequested has special meanings:
+ // -1 sLen == hLen
+ // -2 salt length is maximized
+ // -N reserved
+ size_t sLen;
+ if (sLenRequested == -1) {
+ sLen = hLen;
+ } else if (sLenRequested == -2) {
+ sLen = emLen - hLen - 2;
+ } else if (sLenRequested < 0) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_SLEN_CHECK_FAILED);
+ goto err;
+ } else {
+ sLen = (size_t)sLenRequested;
+ }
+
+ if (emLen - hLen - 2 < sLen) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
+ goto err;
+ }
+
+ if (sLen > 0) {
+ salt = OPENSSL_malloc(sLen);
+ if (!salt) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ if (!RAND_bytes(salt, sLen)) {
+ goto err;
+ }
+ }
+ maskedDBLen = emLen - hLen - 1;
+ H = EM + maskedDBLen;
+
+ EVP_MD_CTX ctx;
+ EVP_MD_CTX_init(&ctx);
+ int digest_ok = EVP_DigestInit_ex(&ctx, Hash, NULL) &&
+ EVP_DigestUpdate(&ctx, kPSSZeroes, sizeof(kPSSZeroes)) &&
+ EVP_DigestUpdate(&ctx, mHash, hLen) &&
+ EVP_DigestUpdate(&ctx, salt, sLen) &&
+ EVP_DigestFinal_ex(&ctx, H, NULL);
+ EVP_MD_CTX_cleanup(&ctx);
+ if (!digest_ok) {
+ goto err;
+ }
+
+ // Generate dbMask in place then perform XOR on it
+ if (!PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash)) {
+ goto err;
+ }
+
+ p = EM;
+
+ // Initial PS XORs with all zeroes which is a NOP so just update
+ // pointer. Note from a test above this value is guaranteed to
+ // be non-negative.
+ p += emLen - sLen - hLen - 2;
+ *p++ ^= 0x1;
+ if (sLen > 0) {
+ for (size_t i = 0; i < sLen; i++) {
+ *p++ ^= salt[i];
+ }
+ }
+ if (MSBits) {
+ EM[0] &= 0xFF >> (8 - MSBits);
+ }
+
+ // H is already in place so just set final 0xbc
+
+ EM[emLen - 1] = 0xbc;
+
+ ret = 1;
+
+err:
+ OPENSSL_free(salt);
+
+ return ret;
+}
git://repos.xcallymotion.com / motion2.git / blobdiff