gost_crypt.c

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/**********************************************************************
 *                          gost_crypt.c                              *
 *             Copyright (c) 2005-2006 Cryptocom LTD                  *
 *         This file is distributed under the same license as OpenSSL *
 *                                                                    *
 *       OpenSSL interface to GOST 28147-89 cipher functions          *
 *          Requires OpenSSL 0.9.9 for compilation                    *
 **********************************************************************/
#include <string.h>
#include "gost89.h"
#include <openssl/rand.h>
#include "e_gost_err.h"
#include "gost_lcl.h"
static int gost_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key, 
    const unsigned char *iv, int enc);
static int  gost_cipher_init_cpa(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc);
/* Handles block of data in CFB mode */         
static int  gost_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl);
/* Handles block of data in CNT mode */         
static int  gost_cipher_do_cnt(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl);
/* Cleanup function */          
static int gost_cipher_cleanup(EVP_CIPHER_CTX *);
/* set/get cipher parameters */
static int gost89_set_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params);
static int gost89_get_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params);
/* Control function */
static int gost_cipher_ctl(EVP_CIPHER_CTX *ctx,int type,int arg,void *ptr);

EVP_CIPHER cipher_gost = 
    {
    NID_id_Gost28147_89,
    1,/*block_size*/
    32,/*key_size*/
    8,/*iv_len */
    EVP_CIPH_CFB_MODE| EVP_CIPH_NO_PADDING |
    EVP_CIPH_CUSTOM_IV| EVP_CIPH_RAND_KEY | EVP_CIPH_ALWAYS_CALL_INIT,
    gost_cipher_init,
    gost_cipher_do_cfb,
    gost_cipher_cleanup,
    sizeof(struct ossl_gost_cipher_ctx),/* ctx_size */
    gost89_set_asn1_parameters,
    gost89_get_asn1_parameters,
    gost_cipher_ctl,
    NULL,
    };

EVP_CIPHER cipher_gost_cpacnt = 
    {
    NID_gost89_cnt,
    1,/*block_size*/
    32,/*key_size*/
    8,/*iv_len */
    EVP_CIPH_OFB_MODE| EVP_CIPH_NO_PADDING |
    EVP_CIPH_CUSTOM_IV| EVP_CIPH_RAND_KEY | EVP_CIPH_ALWAYS_CALL_INIT,
    gost_cipher_init_cpa,
    gost_cipher_do_cnt,
    gost_cipher_cleanup,
    sizeof(struct ossl_gost_cipher_ctx), /* ctx_size */
    gost89_set_asn1_parameters,
    gost89_get_asn1_parameters,
    gost_cipher_ctl,
    NULL,
    };

/* Implementation of GOST 28147-89 in MAC (imitovstavka) mode */
/* Init functions which set specific parameters */
static int gost_imit_init_cpa(EVP_MD_CTX *ctx);
/* process block of data */
static int gost_imit_update(EVP_MD_CTX *ctx, const void *data, size_t count);
/* Return computed value */
static int gost_imit_final(EVP_MD_CTX *ctx,unsigned char *md);
/* Copies context */
static int gost_imit_copy(EVP_MD_CTX *to,const EVP_MD_CTX *from);
static int gost_imit_cleanup(EVP_MD_CTX *ctx);
/* Control function, knows how to set MAC key.*/
static int gost_imit_ctrl(EVP_MD_CTX *ctx,int type, int arg, void *ptr);

EVP_MD imit_gost_cpa =
    {
    NID_id_Gost28147_89_MAC,
    NID_undef,
    4,
    0,
    gost_imit_init_cpa,
    gost_imit_update,
    gost_imit_final,
    gost_imit_copy,
    gost_imit_cleanup,
    NULL,
    NULL,
    {0,0,0,0,0},
    8,
    sizeof(struct ossl_gost_imit_ctx), 
    gost_imit_ctrl
    };

/* 
 * Correspondence between gost parameter OIDs and substitution blocks
 * NID field is filed by register_gost_NID function in engine.c
 * upon engine initialization
 */

struct gost_cipher_info gost_cipher_list[]=
    {
/* NID */  /* Subst block */          /* Key meshing*/
/*{NID_id_GostR3411_94_CryptoProParamSet,&GostR3411_94_CryptoProParamSet,0},*/
    {NID_id_Gost28147_89_cc,&GostR3411_94_CryptoProParamSet,0},
    {NID_id_Gost28147_89_CryptoPro_A_ParamSet,&Gost28147_CryptoProParamSetA,1},
    {NID_id_Gost28147_89_CryptoPro_B_ParamSet,&Gost28147_CryptoProParamSetB,1},
    {NID_id_Gost28147_89_CryptoPro_C_ParamSet,&Gost28147_CryptoProParamSetC,1},
    {NID_id_Gost28147_89_CryptoPro_D_ParamSet,&Gost28147_CryptoProParamSetD,1},
    {NID_id_Gost28147_89_TestParamSet,&Gost28147_TestParamSet,1},
    {NID_undef,NULL,0}
    };  

/*  get encryption parameters from crypto network settings
    FIXME For now we use environment var CRYPT_PARAMS as place to 
    store these settings. Actually, it is better to use engine control   command, read from configuration file to set them */
const struct gost_cipher_info *get_encryption_params(ASN1_OBJECT *obj)
    {
    int nid;
    struct gost_cipher_info *param;
    if (!obj)
        {
        const char * params = get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS);
        if (!params || !strlen(params)) 
            return &gost_cipher_list[1];

        nid = OBJ_txt2nid(params);
        if (nid == NID_undef)
            {
            GOSTerr(GOST_F_GET_ENCRYPTION_PARAMS,
                GOST_R_INVALID_CIPHER_PARAM_OID);
            return NULL;
            }   
        }
    else
        {
        nid= OBJ_obj2nid(obj);
        }
    for (param=gost_cipher_list;param->sblock!=NULL && param->nid!=nid; 
         param++);
    if (!param->sblock)
        {
        GOSTerr(GOST_F_GET_ENCRYPTION_PARAMS,GOST_R_INVALID_CIPHER_PARAMS);
        return NULL;
        }   
    return param;
    }

/* Sets cipher param from paramset NID. */
static int gost_cipher_set_param(struct ossl_gost_cipher_ctx *c,int nid)
    {
    const struct gost_cipher_info *param;
    param=get_encryption_params((nid==NID_undef?NULL:OBJ_nid2obj(nid)));
    if (!param) return 0;
    
    c->paramNID = param->nid;
    c->key_meshing=param->key_meshing;
    c->count=0;
    gost_init(&(c->cctx), param->sblock);
    return 1;
    }

/* Initializes EVP_CIPHER_CTX by paramset NID */
static int gost_cipher_init_param(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc, int paramNID,int mode)
    {
    struct ossl_gost_cipher_ctx *c=ctx->cipher_data;
    if (ctx->app_data == NULL)
        {
        if (!gost_cipher_set_param(c,paramNID)) return 0;
        ctx->app_data = ctx->cipher_data;
        }
    if (key) gost_key(&(c->cctx),key);
    if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
    memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
    return 1;
    }   

static int gost_cipher_init_cpa(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
    {
    struct ossl_gost_cipher_ctx *c=ctx->cipher_data;
    gost_init(&(c->cctx),&Gost28147_CryptoProParamSetA);
    c->key_meshing=1;
    c->count=0;
    if(key) gost_key(&(c->cctx),key);
    if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
    memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
    return 1;
    }

/* Initializes EVP_CIPHER_CTX with default values */
int gost_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
    {
    return gost_cipher_init_param(ctx,key,iv,enc,NID_undef,EVP_CIPH_CFB_MODE);
    }   
/* Wrapper around gostcrypt function from gost89.c which perform
 * key meshing when nesseccary 
 */
static void gost_crypt_mesh (void *ctx,unsigned char *iv,unsigned char *buf)
    {
    struct ossl_gost_cipher_ctx *c = ctx;
    if (c->count&&c->key_meshing && c->count%1024==0)
        {
        cryptopro_key_meshing(&(c->cctx),iv);
        }   
    gostcrypt(&(c->cctx),iv,buf);
    c->count+=8;
    }

static void gost_cnt_next (void *ctx, unsigned char *iv, unsigned char *buf)
    {
    struct ossl_gost_cipher_ctx *c = ctx;
    word32 g,go;
    unsigned char buf1[8];
    if (c->count && c->key_meshing && c->count %1024 ==0)
        {
        cryptopro_key_meshing(&(c->cctx),iv);
        }
    if (c->count==0)
        {
        gostcrypt(&(c->cctx),iv,buf1);
        }
    else
        {
        memcpy(buf1,iv,8);
        }   
    g = buf1[0]|(buf1[1]<<8)|(buf1[2]<<16)|(buf1[3]<<24);
    g += 0x01010101;
    buf1[0]=(unsigned char)(g&0xff);
    buf1[1]=(unsigned char)((g>>8)&0xff);
    buf1[2]=(unsigned char)((g>>16)&0xff);
    buf1[3]=(unsigned char)((g>>24)&0xff);
    g = buf1[4]|(buf1[5]<<8)|(buf1[6]<<16)|(buf1[7]<<24);
    go = g;
    g += 0x01010104;
    if (go > g)      /*  overflow*/
        g++;
    buf1[4]=(unsigned char)(g&0xff);
    buf1[5]=(unsigned char)((g>>8)&0xff);
    buf1[6]=(unsigned char)((g>>16)&0xff);
    buf1[7]=(unsigned char)((g>>24)&0xff);
    memcpy(iv,buf1,8);
    gostcrypt(&(c->cctx),buf1,buf);
    c->count +=8;
    }

/* GOST encryption in CFB mode */
int gost_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl)
    {
    const unsigned char *in_ptr=in;
    unsigned char *out_ptr=out;
    size_t i=0;
    size_t j=0;
/* process partial block if any */
    if (ctx->num) 
        {
        for (j=ctx->num,i=0;j<8 && i<inl;j++,i++,in_ptr++,out_ptr++) 
            {
            if (!ctx->encrypt) ctx->buf[j+8]=*in_ptr;
            *out_ptr=ctx->buf[j]^(*in_ptr);
            if (ctx->encrypt) ctx->buf[j+8]=*out_ptr;
            }   
        if (j==8)
            {
            memcpy(ctx->iv,ctx->buf+8,8);
            ctx->num=0;
            }
        else
            {
            ctx->num=j;
            return 1;
            }   
        }   

    for (;i+8<inl;i+=8,in_ptr+=8,out_ptr+=8)
        {
        /*block cipher current iv */
        gost_crypt_mesh(ctx->cipher_data,ctx->iv,ctx->buf);
        /*xor next block of input text with it and output it*/
        /*output this block */
        if (!ctx->encrypt) memcpy(ctx->iv,in_ptr,8);
        for (j=0;j<8;j++)
            {
            out_ptr[j]=ctx->buf[j]^in_ptr[j];
            }   
        /* Encrypt */
        /* Next iv is next block of cipher text*/
        if (ctx->encrypt) memcpy(ctx->iv,out_ptr,8);
        }
/* Process rest of buffer */
    if (i<inl)
        {
        gost_crypt_mesh(ctx->cipher_data,ctx->iv,ctx->buf);
        if (!ctx->encrypt) memcpy(ctx->buf+8,in_ptr,inl-i);
        for (j=0;i<inl;j++,i++)
            {
            out_ptr[j]=ctx->buf[j]^in_ptr[j];
            }           
        ctx->num = j;
        if (ctx->encrypt) memcpy(ctx->buf+8,out_ptr,j);
        }
    else
        {
        ctx->num = 0;
        }   
    return 1;
    }

static int gost_cipher_do_cnt(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl)
    {
    const unsigned char *in_ptr=in;
    unsigned char *out_ptr=out;
    size_t i=0;
    size_t j;
/* process partial block if any */
    if (ctx->num) 
        {
        for (j=ctx->num,i=0;j<8 && i<inl;j++,i++,in_ptr++,out_ptr++) 
            {
            *out_ptr=ctx->buf[j]^(*in_ptr);
            }   
        if (j==8)
            {
            ctx->num=0;
            }
        else
            {
            ctx->num=j;
            return 1;
            }   
        }   

    for (;i+8<inl;i+=8,in_ptr+=8,out_ptr+=8)
        {
        /*block cipher current iv */
        /* Encrypt */
        gost_cnt_next(ctx->cipher_data,ctx->iv,ctx->buf);
        /*xor next block of input text with it and output it*/
        /*output this block */
        for (j=0;j<8;j++)
            {
            out_ptr[j]=ctx->buf[j]^in_ptr[j];
            }   
        }
/* Process rest of buffer */
    if (i<inl)
        {
        gost_cnt_next(ctx->cipher_data,ctx->iv,ctx->buf);
        for (j=0;i<inl;j++,i++)
            {
            out_ptr[j]=ctx->buf[j]^in_ptr[j];
            }           
        ctx->num = j;
        }
    else
        {
        ctx->num = 0;
        }   
    return 1;
    }

/* Cleaning up of EVP_CIPHER_CTX */
int gost_cipher_cleanup(EVP_CIPHER_CTX *ctx) 
    {
    gost_destroy(&((struct ossl_gost_cipher_ctx *)ctx->cipher_data)->cctx);
    ctx->app_data = NULL;
    return 1;
    }   

/* Control function for gost cipher */
int gost_cipher_ctl(EVP_CIPHER_CTX *ctx,int type,int arg,void *ptr)
    {
    switch (type)
        {
        case EVP_CTRL_RAND_KEY:
        {
        if (RAND_bytes((unsigned char *)ptr,ctx->key_len)<=0)
            {
            GOSTerr(GOST_F_GOST_CIPHER_CTL,GOST_R_RANDOM_GENERATOR_ERROR);
            return -1;
            }
        break;
        }
        case EVP_CTRL_PBE_PRF_NID:
            if (ptr) {
                *((int *)ptr)=  NID_id_HMACGostR3411_94;
                return 1;
            } else {
                return 0;
            }   
                
        default:
            GOSTerr(GOST_F_GOST_CIPHER_CTL,GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
            return -1;
        }
    return 1;
    }

/* Set cipher parameters from ASN1 structure */
int gost89_set_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params)
    {
    int len=0;
    unsigned char *buf=NULL;
    unsigned char *p=NULL;
    struct ossl_gost_cipher_ctx *c = ctx->cipher_data;
    GOST_CIPHER_PARAMS *gcp = GOST_CIPHER_PARAMS_new();
    ASN1_OCTET_STRING *os = NULL;
    if (!gcp)
        {
        GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
        return 0;
        }
    if (!ASN1_OCTET_STRING_set(gcp->iv, ctx->iv, ctx->cipher->iv_len))
        {
        GOST_CIPHER_PARAMS_free(gcp);
        GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
        return 0;
        }
    ASN1_OBJECT_free(gcp->enc_param_set);
    gcp->enc_param_set = OBJ_nid2obj(c->paramNID);

    len = i2d_GOST_CIPHER_PARAMS(gcp, NULL);
    p = buf = (unsigned char*)OPENSSL_malloc(len);
    if (!buf)
        {
        GOST_CIPHER_PARAMS_free(gcp);
        GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
        return 0;
        }
    i2d_GOST_CIPHER_PARAMS(gcp, &p);
    GOST_CIPHER_PARAMS_free(gcp);

    os = ASN1_OCTET_STRING_new();

    if(!os || !ASN1_OCTET_STRING_set(os, buf, len))
        {
        OPENSSL_free(buf);
        GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
        return 0;
        }
    OPENSSL_free(buf);

    ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
    return 1;
    }

/* Store parameters into ASN1 structure */
int  gost89_get_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params)
    {
    int ret = -1;
    int len; 
    GOST_CIPHER_PARAMS *gcp = NULL;
    unsigned char *p;
    struct ossl_gost_cipher_ctx *c=ctx->cipher_data;
    if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE)
        {
        return ret;
        }

    p = params->value.sequence->data;

    gcp = d2i_GOST_CIPHER_PARAMS(NULL, (const unsigned char **)&p,
        params->value.sequence->length);

    len = gcp->iv->length;
    if (len != ctx->cipher->iv_len)
        {
        GOST_CIPHER_PARAMS_free(gcp);
        GOSTerr(GOST_F_GOST89_GET_ASN1_PARAMETERS,
            GOST_R_INVALID_IV_LENGTH);
        return -1;
        }
    if (!gost_cipher_set_param(c,OBJ_obj2nid(gcp->enc_param_set)))
        {
        GOST_CIPHER_PARAMS_free(gcp);
        return -1;
        }
    memcpy(ctx->oiv, gcp->iv->data, len);

    GOST_CIPHER_PARAMS_free(gcp);

    return 1;
    }


int gost_imit_init_cpa(EVP_MD_CTX *ctx)
    {
    struct ossl_gost_imit_ctx *c = ctx->md_data;
    memset(c->buffer,0,sizeof(c->buffer));
    memset(c->partial_block,0,sizeof(c->partial_block));
    c->count = 0;
    c->bytes_left=0;
    c->key_meshing=1;
    gost_init(&(c->cctx),&Gost28147_CryptoProParamSetA);
    return 1;
    }

static void mac_block_mesh(struct ossl_gost_imit_ctx *c,const unsigned char *data)
    {
    unsigned char buffer[8];
    /* We are using local buffer for iv because CryptoPro doesn't 
     * interpret internal state of MAC algorithm as iv during keymeshing
     * (but does initialize internal state from iv in key transport
     */
    if (c->key_meshing&& c->count && c->count %1024 ==0)
        {
        cryptopro_key_meshing(&(c->cctx),buffer);
        }
    mac_block(&(c->cctx),c->buffer,data);
    c->count +=8;
    }

int gost_imit_update(EVP_MD_CTX *ctx, const void *data, size_t count)
    {
    struct ossl_gost_imit_ctx *c = ctx->md_data;
    const unsigned char *p = data;
    size_t bytes = count,i;
    if (!(c->key_set)) {
        GOSTerr(GOST_F_GOST_IMIT_UPDATE, GOST_R_MAC_KEY_NOT_SET);
        return 0;
    }
    if (c->bytes_left)
        {
        for (i=c->bytes_left;i<8&&bytes>0;bytes--,i++,p++)
            {
            c->partial_block[i]=*p;
            }
        if (i==8)
            {
            mac_block_mesh(c,c->partial_block);
            }
        else
            {
            c->bytes_left = i;
            return 1;
            }       
        }   
    while (bytes>8)
        {
        mac_block_mesh(c,p);
        p+=8;
        bytes-=8;
        }
    if (bytes>0)
        {
        memcpy(c->partial_block,p,bytes);
        }   
    c->bytes_left=bytes;
    return 1;
    }

int gost_imit_final(EVP_MD_CTX *ctx,unsigned char *md)
    {
    struct ossl_gost_imit_ctx *c = ctx->md_data;
    if (!c->key_set) {
        GOSTerr(GOST_F_GOST_IMIT_FINAL, GOST_R_MAC_KEY_NOT_SET);
        return 0;
    }
    if (c->bytes_left)
        {
        int i;
        for (i=c->bytes_left;i<8;i++)
            {
            c->partial_block[i]=0;
            }
        mac_block_mesh(c,c->partial_block);
        }
    get_mac(c->buffer,32,md);
    return 1;
    }

int gost_imit_ctrl(EVP_MD_CTX *ctx,int type, int arg, void *ptr)
    {
    switch (type)
        {
        case EVP_MD_CTRL_KEY_LEN:
            *((unsigned int*)(ptr)) = 32;
            return 1;
        case EVP_MD_CTRL_SET_KEY:
        {
        if (arg!=32) {
            GOSTerr(GOST_F_GOST_IMIT_CTRL, GOST_R_INVALID_MAC_KEY_LENGTH);
            return 0;
        }

        gost_key(&(((struct ossl_gost_imit_ctx*)(ctx->md_data))->cctx),ptr) ;
        ((struct ossl_gost_imit_ctx*)(ctx->md_data))->key_set = 1;
        return 1;

        }
        default:
            return 0;
        }       
    }

int gost_imit_copy(EVP_MD_CTX *to,const EVP_MD_CTX *from)
    {
    memcpy(to->md_data,from->md_data,sizeof(struct ossl_gost_imit_ctx));
    return 1;
    }

/* Clean up imit ctx */
int gost_imit_cleanup(EVP_MD_CTX *ctx)
    {
    memset(ctx->md_data,0,sizeof(struct ossl_gost_imit_ctx));
    return 1;
    }