diff options
Diffstat (limited to 'libs/luci-lib-nixio/axTLS/crypto/rsa.c')
| -rw-r--r-- | libs/luci-lib-nixio/axTLS/crypto/rsa.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/libs/luci-lib-nixio/axTLS/crypto/rsa.c b/libs/luci-lib-nixio/axTLS/crypto/rsa.c new file mode 100644 index 0000000000..31627bb319 --- /dev/null +++ b/libs/luci-lib-nixio/axTLS/crypto/rsa.c @@ -0,0 +1,268 @@ +/* + * Copyright (c) 2007, Cameron Rich + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * 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. + * * Neither the name of the axTLS project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS 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 COPYRIGHT OWNER OR + * 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. + */ + +/** + * Implements the RSA public encryption algorithm. Uses the bigint library to + * perform its calculations. + */ + +#include <stdio.h> +#include <string.h> +#include <time.h> +#include <stdlib.h> +#include "crypto.h" + +void RSA_priv_key_new(RSA_CTX **ctx, + const uint8_t *modulus, int mod_len, + const uint8_t *pub_exp, int pub_len, + const uint8_t *priv_exp, int priv_len +#if CONFIG_BIGINT_CRT + , const uint8_t *p, int p_len, + const uint8_t *q, int q_len, + const uint8_t *dP, int dP_len, + const uint8_t *dQ, int dQ_len, + const uint8_t *qInv, int qInv_len +#endif + ) +{ + RSA_CTX *rsa_ctx; + BI_CTX *bi_ctx; + RSA_pub_key_new(ctx, modulus, mod_len, pub_exp, pub_len); + rsa_ctx = *ctx; + bi_ctx = rsa_ctx->bi_ctx; + rsa_ctx->d = bi_import(bi_ctx, priv_exp, priv_len); + bi_permanent(rsa_ctx->d); + +#ifdef CONFIG_BIGINT_CRT + rsa_ctx->p = bi_import(bi_ctx, p, p_len); + rsa_ctx->q = bi_import(bi_ctx, q, q_len); + rsa_ctx->dP = bi_import(bi_ctx, dP, dP_len); + rsa_ctx->dQ = bi_import(bi_ctx, dQ, dQ_len); + rsa_ctx->qInv = bi_import(bi_ctx, qInv, qInv_len); + bi_permanent(rsa_ctx->dP); + bi_permanent(rsa_ctx->dQ); + bi_permanent(rsa_ctx->qInv); + bi_set_mod(bi_ctx, rsa_ctx->p, BIGINT_P_OFFSET); + bi_set_mod(bi_ctx, rsa_ctx->q, BIGINT_Q_OFFSET); +#endif +} + +void RSA_pub_key_new(RSA_CTX **ctx, + const uint8_t *modulus, int mod_len, + const uint8_t *pub_exp, int pub_len) +{ + RSA_CTX *rsa_ctx; + BI_CTX *bi_ctx; + + if (*ctx) /* if we load multiple certs, dump the old one */ + RSA_free(*ctx); + + bi_ctx = bi_initialize(); + *ctx = (RSA_CTX *)calloc(1, sizeof(RSA_CTX)); + rsa_ctx = *ctx; + rsa_ctx->bi_ctx = bi_ctx; + rsa_ctx->num_octets = (mod_len & 0xFFF0); + rsa_ctx->m = bi_import(bi_ctx, modulus, mod_len); + bi_set_mod(bi_ctx, rsa_ctx->m, BIGINT_M_OFFSET); + rsa_ctx->e = bi_import(bi_ctx, pub_exp, pub_len); + bi_permanent(rsa_ctx->e); +} + +/** + * Free up any RSA context resources. + */ +void RSA_free(RSA_CTX *rsa_ctx) +{ + BI_CTX *bi_ctx; + if (rsa_ctx == NULL) /* deal with ptrs that are null */ + return; + + bi_ctx = rsa_ctx->bi_ctx; + + bi_depermanent(rsa_ctx->e); + bi_free(bi_ctx, rsa_ctx->e); + bi_free_mod(rsa_ctx->bi_ctx, BIGINT_M_OFFSET); + + if (rsa_ctx->d) + { + bi_depermanent(rsa_ctx->d); + bi_free(bi_ctx, rsa_ctx->d); +#ifdef CONFIG_BIGINT_CRT + bi_depermanent(rsa_ctx->dP); + bi_depermanent(rsa_ctx->dQ); + bi_depermanent(rsa_ctx->qInv); + bi_free(bi_ctx, rsa_ctx->dP); + bi_free(bi_ctx, rsa_ctx->dQ); + bi_free(bi_ctx, rsa_ctx->qInv); + bi_free_mod(rsa_ctx->bi_ctx, BIGINT_P_OFFSET); + bi_free_mod(rsa_ctx->bi_ctx, BIGINT_Q_OFFSET); +#endif + } + + bi_terminate(bi_ctx); + free(rsa_ctx); +} + +/** + * @brief Use PKCS1.5 for decryption/verification. + * @param ctx [in] The context + * @param in_data [in] The data to encrypt (must be < modulus size-11) + * @param out_data [out] The encrypted data. + * @param is_decryption [in] Decryption or verify operation. + * @return The number of bytes that were originally encrypted. -1 on error. + * @see http://www.rsasecurity.com/rsalabs/node.asp?id=2125 + */ +int RSA_decrypt(const RSA_CTX *ctx, const uint8_t *in_data, + uint8_t *out_data, int is_decryption) +{ + const int byte_size = ctx->num_octets; + int i, size; + bigint *decrypted_bi, *dat_bi; + uint8_t *block = (uint8_t *)alloca(byte_size); + + memset(out_data, 0, byte_size); /* initialise */ + + /* decrypt */ + dat_bi = bi_import(ctx->bi_ctx, in_data, byte_size); +#ifdef CONFIG_SSL_CERT_VERIFICATION + decrypted_bi = is_decryption ? /* decrypt or verify? */ + RSA_private(ctx, dat_bi) : RSA_public(ctx, dat_bi); +#else /* always a decryption */ + decrypted_bi = RSA_private(ctx, dat_bi); +#endif + + /* convert to a normal block */ + bi_export(ctx->bi_ctx, decrypted_bi, block, byte_size); + + i = 10; /* start at the first possible non-padded byte */ + +#ifdef CONFIG_SSL_CERT_VERIFICATION + if (is_decryption == 0) /* PKCS1.5 signing pads with "0xff"s */ + { + while (block[i++] == 0xff && i < byte_size); + + if (block[i-2] != 0xff) + i = byte_size; /*ensure size is 0 */ + } + else /* PKCS1.5 encryption padding is random */ +#endif + { + while (block[i++] && i < byte_size); + } + size = byte_size - i; + + /* get only the bit we want */ + if (size > 0) + memcpy(out_data, &block[i], size); + + return size ? size : -1; +} + +/** + * Performs m = c^d mod n + */ +bigint *RSA_private(const RSA_CTX *c, bigint *bi_msg) +{ +#ifdef CONFIG_BIGINT_CRT + return bi_crt(c->bi_ctx, bi_msg, c->dP, c->dQ, c->p, c->q, c->qInv); +#else + BI_CTX *ctx = c->bi_ctx; + ctx->mod_offset = BIGINT_M_OFFSET; + return bi_mod_power(ctx, bi_msg, c->d); +#endif +} + +#ifdef CONFIG_SSL_FULL_MODE +/** + * Used for diagnostics. + */ +void RSA_print(const RSA_CTX *rsa_ctx) +{ + if (rsa_ctx == NULL) + return; + + printf("----------------- RSA DEBUG ----------------\n"); + printf("Size:\t%d\n", rsa_ctx->num_octets); + bi_print("Modulus", rsa_ctx->m); + bi_print("Public Key", rsa_ctx->e); + bi_print("Private Key", rsa_ctx->d); +} +#endif + +#if defined(CONFIG_SSL_CERT_VERIFICATION) || defined(CONFIG_SSL_GENERATE_X509_CERT) +/** + * Performs c = m^e mod n + */ +bigint *RSA_public(const RSA_CTX * c, bigint *bi_msg) +{ + c->bi_ctx->mod_offset = BIGINT_M_OFFSET; + return bi_mod_power(c->bi_ctx, bi_msg, c->e); +} + +/** + * Use PKCS1.5 for encryption/signing. + * see http://www.rsasecurity.com/rsalabs/node.asp?id=2125 + */ +int RSA_encrypt(const RSA_CTX *ctx, const uint8_t *in_data, uint16_t in_len, + uint8_t *out_data, int is_signing) +{ + int byte_size = ctx->num_octets; + int num_pads_needed = byte_size-in_len-3; + bigint *dat_bi, *encrypt_bi; + + /* note: in_len+11 must be > byte_size */ + out_data[0] = 0; /* ensure encryption block is < modulus */ + + if (is_signing) + { + out_data[1] = 1; /* PKCS1.5 signing pads with "0xff"'s */ + memset(&out_data[2], 0xff, num_pads_needed); + } + else /* randomize the encryption padding with non-zero bytes */ + { + out_data[1] = 2; + get_random_NZ(num_pads_needed, &out_data[2]); + } + + out_data[2+num_pads_needed] = 0; + memcpy(&out_data[3+num_pads_needed], in_data, in_len); + + /* now encrypt it */ + dat_bi = bi_import(ctx->bi_ctx, out_data, byte_size); + encrypt_bi = is_signing ? RSA_private(ctx, dat_bi) : + RSA_public(ctx, dat_bi); + bi_export(ctx->bi_ctx, encrypt_bi, out_data, byte_size); + + /* save a few bytes of memory */ + bi_clear_cache(ctx->bi_ctx); + return byte_size; +} + +#endif /* CONFIG_SSL_CERT_VERIFICATION */ |