/* crypto/evp/evp_enc.c */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #include #include "cryptlib.h" #include #include #include #ifndef OPENSSL_NO_ENGINE #include #endif #include "constant_time_locl.h" #include "evp_locl.h" const char EVP_version[]="EVP" OPENSSL_VERSION_PTEXT; void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx) { memset(ctx,0,sizeof(EVP_CIPHER_CTX)); /* ctx->cipher=NULL; */ } EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void) { EVP_CIPHER_CTX *ctx=OPENSSL_malloc(sizeof *ctx); if (ctx) EVP_CIPHER_CTX_init(ctx); return ctx; } int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, const unsigned char *key, const unsigned char *iv, int enc) { if (cipher) EVP_CIPHER_CTX_init(ctx); return EVP_CipherInit_ex(ctx,cipher,NULL,key,iv,enc); } int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl, const unsigned char *key, const unsigned char *iv, int enc) { if (enc == -1) enc = ctx->encrypt; else { if (enc) enc = 1; ctx->encrypt = enc; } #ifndef OPENSSL_NO_ENGINE /* Whether it's nice or not, "Inits" can be used on "Final"'d contexts * so this context may already have an ENGINE! Try to avoid releasing * the previous handle, re-querying for an ENGINE, and having a * reinitialisation, when it may all be unecessary. */ if (ctx->engine && ctx->cipher && (!cipher || (cipher && (cipher->nid == ctx->cipher->nid)))) goto skip_to_init; #endif if (cipher) { /* Ensure a context left lying around from last time is cleared * (the previous check attempted to avoid this if the same * ENGINE and EVP_CIPHER could be used). */ EVP_CIPHER_CTX_cleanup(ctx); /* Restore encrypt field: it is zeroed by cleanup */ ctx->encrypt = enc; #ifndef OPENSSL_NO_ENGINE if(impl) { if (!ENGINE_init(impl)) { EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR); return 0; } } else /* Ask if an ENGINE is reserved for this job */ impl = ENGINE_get_cipher_engine(cipher->nid); if(impl) { /* There's an ENGINE for this job ... (apparently) */ const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid); if(!c) { /* One positive side-effect of US's export * control history, is that we should at least * be able to avoid using US mispellings of * "initialisation"? */ EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR); return 0; } /* We'll use the ENGINE's private cipher definition */ cipher = c; /* Store the ENGINE functional reference so we know * 'cipher' came from an ENGINE and we need to release * it when done. */ ctx->engine = impl; } else ctx->engine = NULL; #endif ctx->cipher=cipher; if (ctx->cipher->ctx_size) { ctx->cipher_data=OPENSSL_malloc(ctx->cipher->ctx_size); if (!ctx->cipher_data) { EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE); return 0; } } else { ctx->cipher_data = NULL; } ctx->key_len = cipher->key_len; ctx->flags = 0; if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT) { if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) { EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR); return 0; } } } else if(!ctx->cipher) { EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET); return 0; } #ifndef OPENSSL_NO_ENGINE skip_to_init: #endif /* we assume block size is a power of 2 in *cryptUpdate */ OPENSSL_assert(ctx->cipher->block_size == 1 || ctx->cipher->block_size == 8 || ctx->cipher->block_size == 16); if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) { switch(EVP_CIPHER_CTX_mode(ctx)) { case EVP_CIPH_STREAM_CIPHER: case EVP_CIPH_ECB_MODE: break; case EVP_CIPH_CFB_MODE: case EVP_CIPH_OFB_MODE: ctx->num = 0; /* fall-through */ case EVP_CIPH_CBC_MODE: OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <= (int)sizeof(ctx->iv)); if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx)); memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx)); break; default: return 0; break; } } if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) { if(!ctx->cipher->init(ctx,key,iv,enc)) return 0; } ctx->buf_len=0; ctx->final_used=0; ctx->block_mask=ctx->cipher->block_size-1; return 1; } int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, const unsigned char *in, int inl) { if (ctx->encrypt) return EVP_EncryptUpdate(ctx,out,outl,in,inl); else return EVP_DecryptUpdate(ctx,out,outl,in,inl); } int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { if (ctx->encrypt) return EVP_EncryptFinal_ex(ctx,out,outl); else return EVP_DecryptFinal_ex(ctx,out,outl); } int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { if (ctx->encrypt) return EVP_EncryptFinal(ctx,out,outl); else return EVP_DecryptFinal(ctx,out,outl); } int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, const unsigned char *key, const unsigned char *iv) { return EVP_CipherInit(ctx, cipher, key, iv, 1); } int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx,const EVP_CIPHER *cipher, ENGINE *impl, const unsigned char *key, const unsigned char *iv) { return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1); } int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, const unsigned char *key, const unsigned char *iv) { return EVP_CipherInit(ctx, cipher, key, iv, 0); } int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl, const unsigned char *key, const unsigned char *iv) { return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0); } int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, const unsigned char *in, int inl) { int i,j,bl; if (inl <= 0) { *outl = 0; return inl == 0; } if(ctx->buf_len == 0 && (inl&(ctx->block_mask)) == 0) { if(ctx->cipher->do_cipher(ctx,out,in,inl)) { *outl=inl; return 1; } else { *outl=0; return 0; } } i=ctx->buf_len; bl=ctx->cipher->block_size; OPENSSL_assert(bl <= (int)sizeof(ctx->buf)); if (i != 0) { if (i+inl < bl) { memcpy(&(ctx->buf[i]),in,inl); ctx->buf_len+=inl; *outl=0; return 1; } else { j=bl-i; memcpy(&(ctx->buf[i]),in,j); if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0; inl-=j; in+=j; out+=bl; *outl=bl; } } else *outl = 0; i=inl&(bl-1); inl-=i; if (inl > 0) { if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0; *outl+=inl; } if (i != 0) memcpy(ctx->buf,&(in[inl]),i); ctx->buf_len=i; return 1; } int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { int ret; ret = EVP_EncryptFinal_ex(ctx, out, outl); return ret; } int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { int n,ret; unsigned int i, b, bl; b=ctx->cipher->block_size; OPENSSL_assert(b <= sizeof ctx->buf); if (b == 1) { *outl=0; return 1; } bl=ctx->buf_len; if (ctx->flags & EVP_CIPH_NO_PADDING) { if(bl) { EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH); return 0; } *outl = 0; return 1; } n=b-bl; for (i=bl; ibuf[i]=n; ret=ctx->cipher->do_cipher(ctx,out,ctx->buf,b); if(ret) *outl=b; return ret; } int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, const unsigned char *in, int inl) { int fix_len; unsigned int b; if (inl <= 0) { *outl = 0; return inl == 0; } if (ctx->flags & EVP_CIPH_NO_PADDING) return EVP_EncryptUpdate(ctx, out, outl, in, inl); b=ctx->cipher->block_size; OPENSSL_assert(b <= sizeof ctx->final); if(ctx->final_used) { memcpy(out,ctx->final,b); out+=b; fix_len = 1; } else fix_len = 0; if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0; /* if we have 'decrypted' a multiple of block size, make sure * we have a copy of this last block */ if (b > 1 && !ctx->buf_len) { *outl-=b; ctx->final_used=1; memcpy(ctx->final,&out[*outl],b); } else ctx->final_used = 0; if (fix_len) *outl += b; return 1; } int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { int ret; ret = EVP_DecryptFinal_ex(ctx, out, outl); return ret; } int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { unsigned int i, b; unsigned char pad, padding_good; *outl=0; b=(unsigned int)(ctx->cipher->block_size); if (ctx->flags & EVP_CIPH_NO_PADDING) { if(ctx->buf_len) { EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH); return 0; } *outl = 0; return 1; } if (b > 1) { if (ctx->buf_len || !ctx->final_used) { EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_WRONG_FINAL_BLOCK_LENGTH); return(0); } OPENSSL_assert(b <= sizeof ctx->final); pad=ctx->final[b-1]; padding_good = (unsigned char)(~constant_time_is_zero_8(pad)); padding_good &= constant_time_ge_8(b, pad); for (i = 1; i < b; ++i) { unsigned char is_pad_index = constant_time_lt_8(i, pad); unsigned char pad_byte_good = constant_time_eq_8(ctx->final[b-i-1], pad); padding_good &= constant_time_select_8(is_pad_index, pad_byte_good, 0xff); } /* * At least 1 byte is always padding, so we always write b - 1 * bytes to avoid a timing leak. The caller is required to have |b| * bytes space in |out| by the API contract. */ for (i = 0; i < b - 1; ++i) out[i] = ctx->final[i] & padding_good; /* Safe cast: for a good padding, EVP_MAX_IV_LENGTH >= b >= pad */ *outl = padding_good & ((unsigned char)(b - pad)); return padding_good & 1; } else { *outl = 0; return 1; } } void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx) { if (ctx) { EVP_CIPHER_CTX_cleanup(ctx); OPENSSL_free(ctx); } } int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c) { if (c->cipher != NULL) { if(c->cipher->cleanup && !c->cipher->cleanup(c)) return 0; /* Cleanse cipher context data */ if (c->cipher_data) OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size); } if (c->cipher_data) OPENSSL_free(c->cipher_data); #ifndef OPENSSL_NO_ENGINE if (c->engine) /* The EVP_CIPHER we used belongs to an ENGINE, release the * functional reference we held for this reason. */ ENGINE_finish(c->engine); #endif memset(c,0,sizeof(EVP_CIPHER_CTX)); return 1; } int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen) { if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH) return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL); if(c->key_len == keylen) return 1; if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) { c->key_len = keylen; return 1; } EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH); return 0; } int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad) { if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING; else ctx->flags |= EVP_CIPH_NO_PADDING; return 1; } int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr) { int ret; if(!ctx->cipher) { EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET); return 0; } if(!ctx->cipher->ctrl) { EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED); return 0; } ret = ctx->cipher->ctrl(ctx, type, arg, ptr); if(ret == -1) { EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED); return 0; } return ret; } int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key) { if (ctx->cipher->flags & EVP_CIPH_RAND_KEY) return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key); if (RAND_bytes(key, ctx->key_len) <= 0) return 0; return 1; } int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in) { if ((in == NULL) || (in->cipher == NULL)) { EVPerr(EVP_F_EVP_CIPHER_CTX_COPY,EVP_R_INPUT_NOT_INITIALIZED); return 0; } #ifndef OPENSSL_NO_ENGINE /* Make sure it's safe to copy a cipher context using an ENGINE */ if (in->engine && !ENGINE_init(in->engine)) { EVPerr(EVP_F_EVP_CIPHER_CTX_COPY,ERR_R_ENGINE_LIB); return 0; } #endif EVP_CIPHER_CTX_cleanup(out); memcpy(out,in,sizeof *out); if (in->cipher_data && in->cipher->ctx_size) { out->cipher_data=OPENSSL_malloc(in->cipher->ctx_size); if (!out->cipher_data) { EVPerr(EVP_F_EVP_CIPHER_CTX_COPY,ERR_R_MALLOC_FAILURE); return 0; } memcpy(out->cipher_data,in->cipher_data,in->cipher->ctx_size); } if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY) return in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out); return 1; }