| /* rsa.c |
| * |
| * Copyright (C) 2006-2012 Sawtooth Consulting Ltd. |
| * |
| * This file is part of CyaSSL. |
| * |
| * CyaSSL is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * CyaSSL is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA |
| */ |
| |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include <cyassl/ctaocrypt/rsa.h> |
| #include <cyassl/ctaocrypt/random.h> |
| #include <cyassl/ctaocrypt/error.h> |
| #include <cyassl/ctaocrypt/logging.h> |
| |
| #ifdef SHOW_GEN |
| #include <stdio.h> |
| #endif |
| |
| |
| enum { |
| RSA_PUBLIC_ENCRYPT = 0, |
| RSA_PUBLIC_DECRYPT = 1, |
| RSA_PRIVATE_ENCRYPT = 2, |
| RSA_PRIVATE_DECRYPT = 3, |
| |
| RSA_BLOCK_TYPE_1 = 1, |
| RSA_BLOCK_TYPE_2 = 2, |
| |
| RSA_MIN_SIZE = 512, |
| RSA_MAX_SIZE = 4096, |
| |
| RSA_MIN_PAD_SZ = 11 /* seperator + 0 + pad value + 8 pads */ |
| }; |
| |
| |
| void InitRsaKey(RsaKey* key, void* heap) |
| { |
| key->type = -1; /* haven't decided yet */ |
| key->heap = heap; |
| |
| /* TomsFastMath doesn't use memory allocation */ |
| #ifndef USE_FAST_MATH |
| key->n.dp = key->e.dp = 0; /* public alloc parts */ |
| |
| key->d.dp = key->p.dp = 0; /* private alloc parts */ |
| key->q.dp = key->dP.dp = 0; |
| key->u.dp = key->dQ.dp = 0; |
| #endif |
| } |
| |
| |
| void FreeRsaKey(RsaKey* key) |
| { |
| (void)key; |
| /* TomsFastMath doesn't use memory allocation */ |
| #ifndef USE_FAST_MATH |
| if (key->type == RSA_PRIVATE) { |
| mp_clear(&key->u); |
| mp_clear(&key->dQ); |
| mp_clear(&key->dP); |
| mp_clear(&key->q); |
| mp_clear(&key->p); |
| mp_clear(&key->d); |
| } |
| mp_clear(&key->e); |
| mp_clear(&key->n); |
| #endif |
| } |
| |
| static void RsaPad(const byte* input, word32 inputLen, byte* pkcsBlock, |
| word32 pkcsBlockLen, byte padValue, RNG* rng) |
| { |
| if (inputLen == 0) return; |
| |
| pkcsBlock[0] = 0x0; /* set first byte to zero and advance */ |
| pkcsBlock++; pkcsBlockLen--; |
| pkcsBlock[0] = padValue; /* insert padValue */ |
| |
| if (padValue == RSA_BLOCK_TYPE_1) |
| /* pad with 0xff bytes */ |
| XMEMSET(&pkcsBlock[1], 0xFF, pkcsBlockLen - inputLen - 2); |
| else { |
| /* pad with non-zero random bytes */ |
| word32 padLen = pkcsBlockLen - inputLen - 1, i; |
| RNG_GenerateBlock(rng, &pkcsBlock[1], padLen); |
| |
| /* remove zeros */ |
| for (i = 1; i < padLen; i++) |
| if (pkcsBlock[i] == 0) pkcsBlock[i] = 0x01; |
| } |
| |
| pkcsBlock[pkcsBlockLen-inputLen-1] = 0; /* separator */ |
| XMEMCPY(pkcsBlock+pkcsBlockLen-inputLen, input, inputLen); |
| } |
| |
| |
| static word32 RsaUnPad(const byte *pkcsBlock, unsigned int pkcsBlockLen, |
| byte **output, byte padValue) |
| { |
| word32 maxOutputLen = (pkcsBlockLen > 10) ? (pkcsBlockLen - 10) : 0, |
| invalid = 0, |
| i = 1, |
| outputLen; |
| |
| if (pkcsBlock[0] != 0x0) /* skip past zero */ |
| invalid = 1; |
| pkcsBlock++; pkcsBlockLen--; |
| |
| /* Require block type padValue */ |
| invalid = (pkcsBlock[0] != padValue) || invalid; |
| |
| /* skip past the padding until we find the separator */ |
| while (i<pkcsBlockLen && pkcsBlock[i++]) { /* null body */ |
| } |
| if(!(i==pkcsBlockLen || pkcsBlock[i-1]==0)) { |
| CYASSL_MSG("RsaUnPad error, bad formatting"); |
| return 0; |
| } |
| |
| outputLen = pkcsBlockLen - i; |
| invalid = (outputLen > maxOutputLen) || invalid; |
| |
| if (invalid) { |
| CYASSL_MSG("RsaUnPad error, bad formatting"); |
| return 0; |
| } |
| |
| *output = (byte *)(pkcsBlock + i); |
| return outputLen; |
| } |
| |
| |
| static int RsaFunction(const byte* in, word32 inLen, byte* out, word32* outLen, |
| int type, RsaKey* key) |
| { |
| #define ERROR_OUT(x) { ret = x; goto done;} |
| |
| mp_int tmp; |
| int ret = 0; |
| word32 keyLen, len; |
| |
| if (mp_init(&tmp) != MP_OKAY) |
| return MP_INIT_E; |
| |
| if (mp_read_unsigned_bin(&tmp, (byte*)in, inLen) != MP_OKAY) |
| ERROR_OUT(MP_READ_E); |
| |
| if (type == RSA_PRIVATE_DECRYPT || type == RSA_PRIVATE_ENCRYPT) { |
| #ifdef RSA_LOW_MEM /* half as much memory but twice as slow */ |
| if (mp_exptmod(&tmp, &key->d, &key->n, &tmp) != MP_OKAY) |
| ERROR_OUT(MP_EXPTMOD_E); |
| #else |
| #define INNER_ERROR_OUT(x) { ret = x; goto inner_done; } |
| |
| mp_int tmpa, tmpb; |
| |
| if (mp_init(&tmpa) != MP_OKAY) |
| ERROR_OUT(MP_INIT_E); |
| |
| if (mp_init(&tmpb) != MP_OKAY) { |
| mp_clear(&tmpa); |
| ERROR_OUT(MP_INIT_E); |
| } |
| |
| /* tmpa = tmp^dP mod p */ |
| if (mp_exptmod(&tmp, &key->dP, &key->p, &tmpa) != MP_OKAY) |
| INNER_ERROR_OUT(MP_EXPTMOD_E); |
| |
| /* tmpb = tmp^dQ mod q */ |
| if (mp_exptmod(&tmp, &key->dQ, &key->q, &tmpb) != MP_OKAY) |
| INNER_ERROR_OUT(MP_EXPTMOD_E); |
| |
| /* tmp = (tmpa - tmpb) * qInv (mod p) */ |
| if (mp_sub(&tmpa, &tmpb, &tmp) != MP_OKAY) |
| INNER_ERROR_OUT(MP_SUB_E); |
| |
| if (mp_mulmod(&tmp, &key->u, &key->p, &tmp) != MP_OKAY) |
| INNER_ERROR_OUT(MP_MULMOD_E); |
| |
| /* tmp = tmpb + q * tmp */ |
| if (mp_mul(&tmp, &key->q, &tmp) != MP_OKAY) |
| INNER_ERROR_OUT(MP_MUL_E); |
| |
| if (mp_add(&tmp, &tmpb, &tmp) != MP_OKAY) |
| INNER_ERROR_OUT(MP_ADD_E); |
| |
| inner_done: |
| mp_clear(&tmpa); |
| mp_clear(&tmpb); |
| |
| if (ret != 0) return ret; |
| |
| #endif /* RSA_LOW_MEM */ |
| } |
| else if (type == RSA_PUBLIC_ENCRYPT || type == RSA_PUBLIC_DECRYPT) { |
| if (mp_exptmod(&tmp, &key->e, &key->n, &tmp) != MP_OKAY) |
| ERROR_OUT(MP_EXPTMOD_E); |
| } |
| else |
| ERROR_OUT(RSA_WRONG_TYPE_E); |
| |
| keyLen = mp_unsigned_bin_size(&key->n); |
| if (keyLen > *outLen) |
| ERROR_OUT(RSA_BUFFER_E); |
| |
| len = mp_unsigned_bin_size(&tmp); |
| |
| /* pad front w/ zeros to match key length */ |
| while (len < keyLen) { |
| *out++ = 0x00; |
| len++; |
| } |
| |
| *outLen = keyLen; |
| |
| /* convert */ |
| if (mp_to_unsigned_bin(&tmp, out) != MP_OKAY) |
| ERROR_OUT(MP_TO_E); |
| |
| done: |
| mp_clear(&tmp); |
| return ret; |
| } |
| |
| |
| int RsaPublicEncrypt(const byte* in, word32 inLen, byte* out, word32 outLen, |
| RsaKey* key, RNG* rng) |
| { |
| int sz = mp_unsigned_bin_size(&key->n), ret; |
| |
| if (sz > (int)outLen) |
| return RSA_BUFFER_E; |
| |
| if (inLen > (word32)(sz - RSA_MIN_PAD_SZ)) |
| return RSA_BUFFER_E; |
| |
| RsaPad(in, inLen, out, sz, RSA_BLOCK_TYPE_2, rng); |
| |
| if ((ret = RsaFunction(out, sz, out, &outLen, RSA_PUBLIC_ENCRYPT, key)) < 0) |
| sz = ret; |
| |
| return sz; |
| } |
| |
| |
| int RsaPrivateDecryptInline(byte* in, word32 inLen, byte** out, RsaKey* key) |
| { |
| int plainLen, ret; |
| |
| if ((ret = RsaFunction(in, inLen, in, &inLen, RSA_PRIVATE_DECRYPT, key)) |
| < 0) { |
| return ret; |
| } |
| |
| plainLen = RsaUnPad(in, inLen, out, RSA_BLOCK_TYPE_2); |
| |
| return plainLen; |
| } |
| |
| |
| int RsaPrivateDecrypt(const byte* in, word32 inLen, byte* out, word32 outLen, |
| RsaKey* key) |
| { |
| int plainLen, ret; |
| byte* tmp; |
| byte* pad = 0; |
| |
| tmp = (byte*)XMALLOC(inLen, key->heap, DYNAMIC_TYPE_RSA); |
| if (tmp == NULL) { |
| return MEMORY_E; |
| } |
| |
| XMEMCPY(tmp, in, inLen); |
| |
| if ((ret = plainLen = RsaPrivateDecryptInline(tmp, inLen, &pad, key)) |
| < 0) { |
| XFREE(tmp, key->heap, DYNAMIC_TYPE_RSA); |
| return ret; |
| } |
| if (plainLen > (int)outLen) |
| plainLen = BAD_FUNC_ARG; |
| else |
| XMEMCPY(out, pad, plainLen); |
| XMEMSET(tmp, 0x00, inLen); |
| |
| XFREE(tmp, key->heap, DYNAMIC_TYPE_RSA); |
| return plainLen; |
| } |
| |
| |
| /* for Rsa Verify */ |
| int RsaSSL_VerifyInline(byte* in, word32 inLen, byte** out, RsaKey* key) |
| { |
| int plainLen, ret; |
| |
| if ((ret = RsaFunction(in, inLen, in, &inLen, RSA_PUBLIC_DECRYPT, key)) |
| < 0) { |
| return ret; |
| } |
| |
| plainLen = RsaUnPad(in, inLen, out, RSA_BLOCK_TYPE_1); |
| |
| return plainLen; |
| } |
| |
| |
| int RsaSSL_Verify(const byte* in, word32 inLen, byte* out, word32 outLen, |
| RsaKey* key) |
| { |
| int plainLen, ret; |
| byte* tmp; |
| byte* pad = 0; |
| |
| tmp = (byte*)XMALLOC(inLen, key->heap, DYNAMIC_TYPE_RSA); |
| if (tmp == NULL) { |
| return MEMORY_E; |
| } |
| |
| XMEMCPY(tmp, in, inLen); |
| |
| if ((ret = plainLen = RsaSSL_VerifyInline(tmp, inLen, &pad, key)) |
| < 0) { |
| XFREE(tmp, key->heap, DYNAMIC_TYPE_RSA); |
| return ret; |
| } |
| |
| if (plainLen > (int)outLen) |
| plainLen = BAD_FUNC_ARG; |
| else |
| XMEMCPY(out, pad, plainLen); |
| XMEMSET(tmp, 0x00, inLen); |
| |
| XFREE(tmp, key->heap, DYNAMIC_TYPE_RSA); |
| return plainLen; |
| } |
| |
| |
| /* for Rsa Sign */ |
| int RsaSSL_Sign(const byte* in, word32 inLen, byte* out, word32 outLen, |
| RsaKey* key, RNG* rng) |
| { |
| int sz = mp_unsigned_bin_size(&key->n), ret; |
| |
| if (sz > (int)outLen) |
| return RSA_BUFFER_E; |
| |
| if (inLen > (word32)(sz - RSA_MIN_PAD_SZ)) |
| return RSA_BUFFER_E; |
| |
| RsaPad(in, inLen, out, sz, RSA_BLOCK_TYPE_1, rng); |
| |
| if ((ret = RsaFunction(out, sz, out, &outLen, RSA_PRIVATE_ENCRYPT,key)) < 0) |
| sz = ret; |
| |
| return sz; |
| } |
| |
| |
| int RsaEncryptSize(RsaKey* key) |
| { |
| return mp_unsigned_bin_size(&key->n); |
| } |
| |
| |
| #ifdef CYASSL_KEY_GEN |
| |
| static const int USE_BBS = 1; |
| |
| static int rand_prime(mp_int* N, int len, RNG* rng, void* heap) |
| { |
| int err, res, type; |
| byte* buf; |
| |
| (void)heap; |
| if (N == NULL || rng == NULL) |
| return BAD_FUNC_ARG; |
| |
| /* get type */ |
| if (len < 0) { |
| type = USE_BBS; |
| len = -len; |
| } else { |
| type = 0; |
| } |
| |
| /* allow sizes between 2 and 512 bytes for a prime size */ |
| if (len < 2 || len > 512) { |
| return BAD_FUNC_ARG; |
| } |
| |
| /* allocate buffer to work with */ |
| buf = (byte*)XMALLOC(len, heap, DYNAMIC_TYPE_RSA); |
| if (buf == NULL) { |
| return MEMORY_E; |
| } |
| XMEMSET(buf, 0, len); |
| |
| do { |
| #ifdef SHOW_GEN |
| printf("."); |
| fflush(stdout); |
| #endif |
| /* generate value */ |
| RNG_GenerateBlock(rng, buf, len); |
| |
| /* munge bits */ |
| buf[0] |= 0x80 | 0x40; |
| buf[len-1] |= 0x01 | ((type & USE_BBS) ? 0x02 : 0x00); |
| |
| /* load value */ |
| if ((err = mp_read_unsigned_bin(N, buf, len)) != MP_OKAY) { |
| XFREE(buf, heap, DYNAMIC_TYPE_RSA); |
| return err; |
| } |
| |
| /* test */ |
| if ((err = mp_prime_is_prime(N, 8, &res)) != MP_OKAY) { |
| XFREE(buf, heap, DYNAMIC_TYPE_RSA); |
| return err; |
| } |
| } while (res == MP_NO); |
| |
| #ifdef LTC_CLEAN_STACK |
| XMEMSET(buf, 0, len); |
| #endif |
| |
| XFREE(buf, heap, DYNAMIC_TYPE_RSA); |
| return 0; |
| } |
| |
| |
| /* Make an RSA key for size bits, with e specified, 65537 is a good e */ |
| int MakeRsaKey(RsaKey* key, int size, long e, RNG* rng) |
| { |
| mp_int p, q, tmp1, tmp2, tmp3; |
| int err; |
| |
| if (key == NULL || rng == NULL) |
| return BAD_FUNC_ARG; |
| |
| if (size < RSA_MIN_SIZE || size > RSA_MAX_SIZE) |
| return BAD_FUNC_ARG; |
| |
| if (e < 3 || (e & 1) == 0) |
| return BAD_FUNC_ARG; |
| |
| if ((err = mp_init_multi(&p, &q, &tmp1, &tmp2, &tmp3, NULL)) != MP_OKAY) |
| return err; |
| |
| err = mp_set_int(&tmp3, e); |
| |
| /* make p */ |
| if (err == MP_OKAY) { |
| do { |
| err = rand_prime(&p, size/16, rng, key->heap); /* size in bytes/2 */ |
| |
| if (err == MP_OKAY) |
| err = mp_sub_d(&p, 1, &tmp1); /* tmp1 = p-1 */ |
| |
| if (err == MP_OKAY) |
| err = mp_gcd(&tmp1, &tmp3, &tmp2); /* tmp2 = gcd(p-1, e) */ |
| } while (err == MP_OKAY && mp_cmp_d(&tmp2, 1) != 0); /* e divdes p-1 */ |
| } |
| |
| /* make q */ |
| if (err == MP_OKAY) { |
| do { |
| err = rand_prime(&q, size/16, rng, key->heap); /* size in bytes/2 */ |
| |
| if (err == MP_OKAY) |
| err = mp_sub_d(&q, 1, &tmp1); /* tmp1 = q-1 */ |
| |
| if (err == MP_OKAY) |
| err = mp_gcd(&tmp1, &tmp3, &tmp2); /* tmp2 = gcd(q-1, e) */ |
| } while (err == MP_OKAY && mp_cmp_d(&tmp2, 1) != 0); /* e divdes q-1 */ |
| } |
| |
| if (err == MP_OKAY) |
| err = mp_init_multi(&key->n, &key->e, &key->d, &key->p, &key->q, NULL); |
| |
| if (err == MP_OKAY) |
| err = mp_init_multi(&key->dP, &key->dP, &key->u, NULL, NULL, NULL); |
| |
| if (err == MP_OKAY) |
| err = mp_sub_d(&p, 1, &tmp2); /* tmp2 = p-1 */ |
| |
| if (err == MP_OKAY) |
| err = mp_lcm(&tmp1, &tmp2, &tmp1); /* tmp1 = lcm(p-1, q-1),last loop */ |
| |
| /* make key */ |
| if (err == MP_OKAY) |
| err = mp_set_int(&key->e, e); /* key->e = e */ |
| |
| if (err == MP_OKAY) /* key->d = 1/e mod lcm(p-1, q-1) */ |
| err = mp_invmod(&key->e, &tmp1, &key->d); |
| |
| if (err == MP_OKAY) |
| err = mp_mul(&p, &q, &key->n); /* key->n = pq */ |
| |
| if (err == MP_OKAY) |
| err = mp_sub_d(&p, 1, &tmp1); |
| |
| if (err == MP_OKAY) |
| err = mp_sub_d(&q, 1, &tmp2); |
| |
| if (err == MP_OKAY) |
| err = mp_mod(&key->d, &tmp1, &key->dP); |
| |
| if (err == MP_OKAY) |
| err = mp_mod(&key->d, &tmp2, &key->dQ); |
| |
| if (err == MP_OKAY) |
| err = mp_invmod(&q, &p, &key->u); |
| |
| if (err == MP_OKAY) |
| err = mp_copy(&p, &key->p); |
| |
| if (err == MP_OKAY) |
| err = mp_copy(&q, &key->q); |
| |
| if (err == MP_OKAY) |
| key->type = RSA_PRIVATE; |
| |
| mp_clear(&tmp3); |
| mp_clear(&tmp2); |
| mp_clear(&tmp1); |
| mp_clear(&q); |
| mp_clear(&p); |
| |
| if (err != MP_OKAY) { |
| FreeRsaKey(key); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| |
| #endif /* CYASLS_KEY_GEN */ |
| |
