cryb-to/lib/rsaref/rsa.c
Dag-Erling Smørgrav ae99587ba4 initial code drop
2014-07-04 11:18:53 +00:00

324 lines
10 KiB
C

/* RSA.C - RSA routines for RSAREF
*/
/* Copyright (C) RSA Laboratories, a division of RSA Data Security,
Inc., created 1991. All rights reserved.
*/
#include "global.h"
#include "rsaref.h"
#include "r_random.h"
#include "rsa.h"
#include "nn.h"
static int RSAPublicBlock PROTO_LIST
((unsigned char *, unsigned int *, unsigned char *, unsigned int,
R_RSA_PUBLIC_KEY *));
static int RSAPrivateBlock PROTO_LIST
((unsigned char *, unsigned int *, unsigned char *, unsigned int,
R_RSA_PRIVATE_KEY *));
/* RSA public-key encryption, according to PKCS #1.
*/
int RSAPublicEncrypt
(output, outputLen, input, inputLen, publicKey, randomStruct)
unsigned char *output; /* output block */
unsigned int *outputLen; /* length of output block */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
R_RSA_PUBLIC_KEY *publicKey; /* RSA public key */
R_RANDOM_STRUCT *randomStruct; /* random structure */
{
int status;
unsigned char byte, pkcsBlock[MAX_RSA_MODULUS_LEN];
unsigned int i, modulusLen;
modulusLen = (publicKey->bits + 7) / 8;
if (inputLen + 11 > modulusLen)
return (RE_LEN);
pkcsBlock[0] = 0;
/* block type 2 */
pkcsBlock[1] = 2;
for (i = 2; i < modulusLen - inputLen - 1; i++) {
/* Find nonzero random byte.
*/
do {
R_GenerateBytes (&byte, 1, randomStruct);
} while (byte == 0);
pkcsBlock[i] = byte;
}
/* separator */
pkcsBlock[i++] = 0;
R_memcpy ((POINTER)&pkcsBlock[i], (POINTER)input, inputLen);
status = RSAPublicBlock
(output, outputLen, pkcsBlock, modulusLen, publicKey);
/* Zeroize sensitive information.
*/
byte = 0;
R_memset ((POINTER)pkcsBlock, 0, sizeof (pkcsBlock));
return (status);
}
/* RSA public-key decryption, according to PKCS #1.
*/
int RSAPublicDecrypt (output, outputLen, input, inputLen, publicKey)
unsigned char *output; /* output block */
unsigned int *outputLen; /* length of output block */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
R_RSA_PUBLIC_KEY *publicKey; /* RSA public key */
{
int status;
unsigned char pkcsBlock[MAX_RSA_MODULUS_LEN];
unsigned int i, modulusLen, pkcsBlockLen;
modulusLen = (publicKey->bits + 7) / 8;
if (inputLen > modulusLen)
return (RE_LEN);
if ((status = RSAPublicBlock
(pkcsBlock, &pkcsBlockLen, input, inputLen, publicKey)))
return (status);
if (pkcsBlockLen != modulusLen)
return (RE_LEN);
/* Require block type 1.
*/
if ((pkcsBlock[0] != 0) || (pkcsBlock[1] != 1))
return (RE_DATA);
for (i = 2; i < modulusLen-1; i++)
if (pkcsBlock[i] != 0xff)
break;
/* separator */
if (pkcsBlock[i++] != 0)
return (RE_DATA);
*outputLen = modulusLen - i;
if (*outputLen + 11 > modulusLen)
return (RE_DATA);
R_memcpy ((POINTER)output, (POINTER)&pkcsBlock[i], *outputLen);
/* Zeroize potentially sensitive information.
*/
R_memset ((POINTER)pkcsBlock, 0, sizeof (pkcsBlock));
return (0);
}
/* RSA private-key encryption, according to PKCS #1.
*/
int RSAPrivateEncrypt (output, outputLen, input, inputLen, privateKey)
unsigned char *output; /* output block */
unsigned int *outputLen; /* length of output block */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
R_RSA_PRIVATE_KEY *privateKey; /* RSA private key */
{
int status;
unsigned char pkcsBlock[MAX_RSA_MODULUS_LEN];
unsigned int i, modulusLen;
modulusLen = (privateKey->bits + 7) / 8;
if (inputLen + 11 > modulusLen)
return (RE_LEN);
pkcsBlock[0] = 0;
/* block type 1 */
pkcsBlock[1] = 1;
for (i = 2; i < modulusLen - inputLen - 1; i++)
pkcsBlock[i] = 0xff;
/* separator */
pkcsBlock[i++] = 0;
R_memcpy ((POINTER)&pkcsBlock[i], (POINTER)input, inputLen);
status = RSAPrivateBlock
(output, outputLen, pkcsBlock, modulusLen, privateKey);
/* Zeroize potentially sensitive information.
*/
R_memset ((POINTER)pkcsBlock, 0, sizeof (pkcsBlock));
return (status);
}
/* RSA private-key decryption, according to PKCS #1.
*/
int RSAPrivateDecrypt (output, outputLen, input, inputLen, privateKey)
unsigned char *output; /* output block */
unsigned int *outputLen; /* length of output block */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
R_RSA_PRIVATE_KEY *privateKey; /* RSA private key */
{
int status;
unsigned char pkcsBlock[MAX_RSA_MODULUS_LEN];
unsigned int i, modulusLen, pkcsBlockLen;
modulusLen = (privateKey->bits + 7) / 8;
if (inputLen > modulusLen)
return (RE_LEN);
if ((status = RSAPrivateBlock
(pkcsBlock, &pkcsBlockLen, input, inputLen, privateKey)))
return (status);
if (pkcsBlockLen != modulusLen)
return (RE_LEN);
/* Require block type 2.
*/
if ((pkcsBlock[0] != 0) || (pkcsBlock[1] != 2))
return (RE_DATA);
for (i = 2; i < modulusLen-1; i++)
/* separator */
if (pkcsBlock[i] == 0)
break;
i++;
if (i >= modulusLen)
return (RE_DATA);
*outputLen = modulusLen - i;
if (*outputLen + 11 > modulusLen)
return (RE_DATA);
R_memcpy ((POINTER)output, (POINTER)&pkcsBlock[i], *outputLen);
/* Zeroize sensitive information.
*/
R_memset ((POINTER)pkcsBlock, 0, sizeof (pkcsBlock));
return (0);
}
/* Raw RSA public-key operation. Output has same length as modulus.
Assumes inputLen < length of modulus.
Requires input < modulus.
*/
static int RSAPublicBlock (output, outputLen, input, inputLen, publicKey)
unsigned char *output; /* output block */
unsigned int *outputLen; /* length of output block */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
R_RSA_PUBLIC_KEY *publicKey; /* RSA public key */
{
NN_DIGIT c[MAX_NN_DIGITS], e[MAX_NN_DIGITS], m[MAX_NN_DIGITS],
n[MAX_NN_DIGITS];
unsigned int eDigits, nDigits;
NN_Decode (m, MAX_NN_DIGITS, input, inputLen);
NN_Decode (n, MAX_NN_DIGITS, publicKey->modulus, MAX_RSA_MODULUS_LEN);
NN_Decode (e, MAX_NN_DIGITS, publicKey->exponent, MAX_RSA_MODULUS_LEN);
nDigits = NN_Digits (n, MAX_NN_DIGITS);
eDigits = NN_Digits (e, MAX_NN_DIGITS);
if (NN_Cmp (m, n, nDigits) >= 0)
return (RE_DATA);
/* Compute c = m^e mod n.
*/
NN_ModExp (c, m, e, eDigits, n, nDigits);
*outputLen = (publicKey->bits + 7) / 8;
NN_Encode (output, *outputLen, c, nDigits);
/* Zeroize sensitive information.
*/
R_memset ((POINTER)c, 0, sizeof (c));
R_memset ((POINTER)m, 0, sizeof (m));
return (0);
}
/* Raw RSA private-key operation. Output has same length as modulus.
Assumes inputLen < length of modulus.
Requires input < modulus.
*/
static int RSAPrivateBlock (output, outputLen, input, inputLen, privateKey)
unsigned char *output; /* output block */
unsigned int *outputLen; /* length of output block */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
R_RSA_PRIVATE_KEY *privateKey; /* RSA private key */
{
NN_DIGIT c[MAX_NN_DIGITS], cP[MAX_NN_DIGITS], cQ[MAX_NN_DIGITS],
dP[MAX_NN_DIGITS], dQ[MAX_NN_DIGITS], mP[MAX_NN_DIGITS],
mQ[MAX_NN_DIGITS], n[MAX_NN_DIGITS], p[MAX_NN_DIGITS], q[MAX_NN_DIGITS],
qInv[MAX_NN_DIGITS], t[MAX_NN_DIGITS];
unsigned int cDigits, nDigits, pDigits;
NN_Decode (c, MAX_NN_DIGITS, input, inputLen);
NN_Decode (n, MAX_NN_DIGITS, privateKey->modulus, MAX_RSA_MODULUS_LEN);
NN_Decode (p, MAX_NN_DIGITS, privateKey->prime[0], MAX_RSA_PRIME_LEN);
NN_Decode (q, MAX_NN_DIGITS, privateKey->prime[1], MAX_RSA_PRIME_LEN);
NN_Decode
(dP, MAX_NN_DIGITS, privateKey->primeExponent[0], MAX_RSA_PRIME_LEN);
NN_Decode
(dQ, MAX_NN_DIGITS, privateKey->primeExponent[1], MAX_RSA_PRIME_LEN);
NN_Decode (qInv, MAX_NN_DIGITS, privateKey->coefficient, MAX_RSA_PRIME_LEN);
cDigits = NN_Digits (c, MAX_NN_DIGITS);
nDigits = NN_Digits (n, MAX_NN_DIGITS);
pDigits = NN_Digits (p, MAX_NN_DIGITS);
if (NN_Cmp (c, n, nDigits) >= 0)
return (RE_DATA);
/* Compute mP = cP^dP mod p and mQ = cQ^dQ mod q. (Assumes q has
length at most pDigits, i.e., p > q.)
*/
NN_Mod (cP, c, cDigits, p, pDigits);
NN_Mod (cQ, c, cDigits, q, pDigits);
NN_ModExp (mP, cP, dP, pDigits, p, pDigits);
NN_AssignZero (mQ, nDigits);
NN_ModExp (mQ, cQ, dQ, pDigits, q, pDigits);
/* Chinese Remainder Theorem:
m = ((((mP - mQ) mod p) * qInv) mod p) * q + mQ.
*/
if (NN_Cmp (mP, mQ, pDigits) >= 0)
NN_Sub (t, mP, mQ, pDigits);
else {
NN_Sub (t, mQ, mP, pDigits);
NN_Sub (t, p, t, pDigits);
}
NN_ModMult (t, t, qInv, p, pDigits);
NN_Mult (t, t, q, pDigits);
NN_Add (t, t, mQ, nDigits);
*outputLen = (privateKey->bits + 7) / 8;
NN_Encode (output, *outputLen, t, nDigits);
/* Zeroize sensitive information.
*/
R_memset ((POINTER)c, 0, sizeof (c));
R_memset ((POINTER)cP, 0, sizeof (cP));
R_memset ((POINTER)cQ, 0, sizeof (cQ));
R_memset ((POINTER)dP, 0, sizeof (dP));
R_memset ((POINTER)dQ, 0, sizeof (dQ));
R_memset ((POINTER)mP, 0, sizeof (mP));
R_memset ((POINTER)mQ, 0, sizeof (mQ));
R_memset ((POINTER)p, 0, sizeof (p));
R_memset ((POINTER)q, 0, sizeof (q));
R_memset ((POINTER)qInv, 0, sizeof (qInv));
R_memset ((POINTER)t, 0, sizeof (t));
return (0);
}