/*Copyright (C) 2001 Benjamin Lynn (blynn@cs.stanford.edu)See LICENSE for license*/#include <string.h>#include "ibe.h"#include "format.h"#include "crypto.h"enum {    crypt_buf_size = 100};char *FMT_get_year(void){    time_t tt;    struct tm *tmt;    char *s;    int year;    time(&tt);    tmt = gmtime(&tt);    s = (char *) malloc(5);    year = 1900 + tmt->tm_year;    if (year > 9999) year = 9999;    //Y10K bug: need to fix eventually =]    sprintf(s, "%d", year);    return s;}char *FMT_make_id(char *addr, char *subject, params_t params){    char *year = FMT_get_year();    int i;    char *s;    if (!addr) {	return NULL;    }    //XXX: yet another magic number    i = strlen(addr) + strlen(IBE_system(params)) + 1000;    if (subject) i += strlen(subject);    s = (char *) malloc(i);    i = sprintf(s, "purpose=email&date=%s&id=%s&", year, addr);    if (subject) {	i += sprintf(&s[i], "subject=%s&", subject);    }    sprintf(&s[i], "system=%s", IBE_system(params));    free(year);    return s;}static void advance_to(char *s, FILE *infp){    char line[crypt_buf_size];    for (;;) {	fgets(line, crypt_buf_size, infp);	if (feof(infp)) break;	if (!strncmp(s, line, strlen(s))) break;    }}static void mime_put(byte_string_t bs, FILE *outfp){    char out[1024];    int outl;    int i, l;    EVP_ENCODE_CTX ctx;    EVP_EncodeInit(&ctx);    for (i=0; i<bs->len; i+=l) {	if (i+crypt_buf_size > bs->len) {	    l = bs->len - i;	} else {	    l = crypt_buf_size;	}	EVP_EncodeUpdate(&ctx,out,&outl,&bs->data[i],l);	fwrite(out, 1, outl, outfp);    }    EVP_EncodeFinal(&ctx,out,&outl);    fwrite(out, 1, outl, outfp);}static void mime_get(byte_string_t bs, FILE *infp){    char line[crypt_buf_size];    int l, l2;    EVP_ENCODE_CTX mime;    byte_string_init(bs, 1024);    EVP_DecodeInit(&mime);    l = 0;    for (;;) {	fgets(line, crypt_buf_size, infp);	if (feof(infp)) break;	//break on blank line = "\n" or "\r\n"	if (strlen(line) <= 2) break;	EVP_DecodeUpdate(&mime, &bs->data[l], &l2, (unsigned char *) line, strlen(line));	l += l2;	if (bs->len - l < crypt_buf_size) {	    byte_string_reinit(bs, bs->len * 2);	}    }    EVP_DecodeFinal(&mime, &bs->data[l], &l2);    byte_string_reinit(bs, l + l2);}void FMT_encrypt_stream_array(char **id, int idcount,	FILE *infp, FILE *outfp, params_t params){    byte_string_t U, K;    byte_string_t *V;    unsigned char in[crypt_buf_size];    unsigned char *out;    int inl, outl;    crypto_ctx_t ctx;    EVP_ENCODE_CTX mime;    unsigned char data[1024];    int i;    int count;    out = (unsigned char *) alloca(crypt_buf_size + crypto_block_size());    V = (byte_string_t *) alloca(sizeof(byte_string_t) * idcount);    fprintf(outfp, "\n-----BEGIN IBE-----\n");    crypto_generate_key(K);    IBE_hide_key_array(U, V, id, idcount, K, params);    fprintf(outfp, "\nU:\n");    mime_put(U, outfp);    fprintf(outfp, "\n");    for (i=0; i<idcount; i++) {	fprintf(outfp, "\nID:\n");	fprintf(outfp, "%s\n", id[i]);	fprintf(outfp, "\nV:\n");	mime_put(V[i], outfp);	fprintf(outfp, "\n");	byte_string_clear(V[i]);    }    fprintf(outfp, "\nW:\n");    crypto_ctx_init(ctx);    crypto_encrypt_init(ctx, K);    EVP_EncodeInit(&mime);    for (;;) {	inl = fread(in, 1, crypt_buf_size, infp);	if (inl < 0) {	    fprintf(stderr, "read error\n");	    exit(1);	}	crypto_encrypt_update(ctx, out, &outl, in, inl);	EVP_EncodeUpdate(&mime, data, &count, out, outl);	fwrite(data, 1, count, outfp);	if (feof(infp)) break;    }    crypto_encrypt_final(ctx, out, &outl);    crypto_ctx_clear(ctx);    EVP_EncodeUpdate(&mime, data, &count, out, outl);    fwrite(data, 1, count, outfp);    EVP_EncodeFinal(&mime, data, &count);    fwrite(data, 1, count, outfp);    fprintf(outfp, "\n-----END IBE-----\n");    byte_string_clear(K);    byte_string_clear(U);}void FMT_encrypt_stream(char *id, FILE *infp, FILE *outfp, params_t params){    FMT_encrypt_stream_array(&id, 1, infp, outfp, params);}int FMT_decrypt_stream(char *id, byte_string_t key,	FILE *infp, FILE *outfp, params_t params){    byte_string_t U;    byte_string_t K, V;    crypto_ctx_t ctx;    unsigned char in[crypt_buf_size];    unsigned char out[200]; //TODO: what should this be?    int inl, outl;    unsigned char data[1024];    int count;    EVP_ENCODE_CTX mime;    int result = 0;    char *s, slen;    int status;    advance_to("-----BEGIN IBE-----", infp);    advance_to("U:", infp);    mime_get(U, infp);    slen = strlen(id) + 2;    s = (char *) alloca(sizeof(char) * slen);    for(;;) {	advance_to("ID:", infp);	if (feof(infp)) {	    //ID not found	    return 0;	}	fgets(s, slen, infp);	if (s[strlen(id)] == '\n') { //correct length?	    if (!strncmp(s, id, strlen(id))) { //compares?		break; //email has ID for us	    }	}    }    advance_to("V:", infp);    mime_get(V, infp);    status = IBE_reveal_key(K, U, V, key, params);    if (status != 1) {	fprintf(outfp, "WARNING: KMAC MISMATCH. INVALID CIPHERTEXT!\n");	byte_string_clear(V);	byte_string_clear(K);	return result;    }    advance_to("W:", infp);    crypto_ctx_init(ctx);    crypto_decrypt_init(ctx, K);    EVP_DecodeInit(&mime);    for (;;) {	fgets(in, crypt_buf_size, infp);	inl = strlen(in);	if (inl < 0) {	    fprintf(stderr, "read error\n");	    exit(1);	}	if (inl < 2) break;	EVP_DecodeUpdate(&mime, data, &count, in, inl);	crypto_decrypt_update(ctx, out, &outl, data, count);	fwrite(out, 1, outl, outfp);    }    EVP_DecodeFinal(&mime, data, &count);    crypto_decrypt_update(ctx, out, &outl, data, count);    fwrite(out, 1, outl, outfp);    if (1 != crypto_decrypt_final(ctx, out, &outl)) {	fprintf(outfp, "crypto_decrypt_final() failed!\n");    } else {	result = 1;    }    fwrite(out, 1, outl, outfp);    crypto_ctx_clear(ctx);    byte_string_clear(K);    byte_string_clear(U);    byte_string_clear(V);    return result;}int FMT_crypt_save_fp(FILE *outfp, byte_string_t bs, const char *password){    byte_string_t K, W;    byte_string_set(K, password);    crypto_encrypt(W, bs, K);    fprintf(outfp, "\nW:\n");    mime_put(W, outfp);    byte_string_clear(K);    byte_string_clear(W);    return 1;}int FMT_crypt_save(const char *fname, byte_string_t bs, const char *password){    FILE *fp;    int status;    fp = fopen(fname, "w");    if (!fp) return 0;    status = FMT_crypt_save_fp(fp, bs, password);    fclose(fp);    return status;}int FMT_crypt_load(const char *fname, byte_string_t bs, const char *password){    FILE *infp;    byte_string_t K, W;    int result = 0;    infp = fopen(fname, "r");    if (!infp) return 0;    byte_string_set(K, password);    advance_to("W:", infp);    mime_get(W, infp);    if (1 != crypto_decrypt(bs, W, K)) {	fprintf(stderr, "crypto_decrypt() failed!\n");    } else {	result = 1;    }    fclose(infp);    byte_string_clear(K);    byte_string_clear(W);    return result;}int FMT_load_byte_string(const char *filename, byte_string_t bs){    FILE *fp;    fp = fopen(filename, "r");    if (!fp) return 0;    mime_get(bs, fp);    fclose(fp);    return 1;}int FMT_save_byte_string(const char *filename, byte_string_t bs){    FILE *fp;    fp = fopen(filename, "w");    if (!fp) return 0;    mime_put(bs, fp);    fclose(fp);    return 1;}int FMT_load_raw_byte_string(byte_string_t bs, char *file)//load a raw byte string from a file{    int max = 1024;    int len = 0;    FILE *fp;    fp = fopen(file, "r");    if (!fp) {	return 0;    }    byte_string_init(bs, max);    for(;;) {	len += fread(&bs->data[len], 1, max - len, fp);	if (len == max) {	    max *= 2;	    byte_string_reinit(bs, max);	} else {	    if (!feof(fp)) {		fclose(fp);		byte_string_clear(bs);		return 0;	    }	    fclose(fp);	    break;	}    }    byte_string_reinit(bs, len);    return 1;}int FMT_split_master(char **fname, byte_string_t master, int t, int n, params_t params){    int i;    byte_string_t mshare[n];    int result = 1;    IBE_split_master(mshare, master, t, n, params);    for (i=0; i<n; i++) {	if (1 != FMT_save_byte_string(fname[i], mshare[i])) {	    fprintf(stderr, "error writing to %s\n", fname[i]);	    result = 0;	    break;	}    }    for (i=0; i<n; i++) {	byte_string_clear(mshare[i]);    }    return result;}int FMT_construct_master(byte_string_t master,	char **fname, int t, params_t params){    int i;    byte_string_t mshare[t];    for (i=0; i<t; i++) {	if (1 != FMT_load_byte_string(fname[i], mshare[i])) {	    fprintf(stderr, "error loading %s\n", fname[i]);	    return 0;	}    }    IBE_construct_master(master, mshare, params);    for (i=0; i<t; i++) {	byte_string_clear(mshare[i]);    }    return 1;}int FMT_save_params(char *filename, params_t params){    int result;    byte_string_t bs;    IBE_serialize_params(bs, params);    result = FMT_save_byte_string(filename, bs);    byte_string_clear(bs);    return result;}int FMT_load_params(params_t params, char *filename){    byte_string_t bs;    int result;    result = FMT_load_byte_string(filename, bs);    if (!result) {	return 0;    }    result = IBE_deserialize_params(params, bs);    byte_string_clear(bs);    return result;}