X-Git-Url: https://pd.if.org/git/?p=zpackage;a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fencauth%2Focb3%2Focb3_decrypt_last.c;fp=libtomcrypt%2Fsrc%2Fencauth%2Focb3%2Focb3_decrypt_last.c;h=0000000000000000000000000000000000000000;hp=70608dc7676db33f5bbb6c9adbea8c804aba1c8f;hb=a670d5d3211446a123f1af646c867ee4aabadc49;hpb=72b60d5f77676b6b500d58bae81a27923fa1bee7 diff --git a/libtomcrypt/src/encauth/ocb3/ocb3_decrypt_last.c b/libtomcrypt/src/encauth/ocb3/ocb3_decrypt_last.c deleted file mode 100644 index 70608dc..0000000 --- a/libtomcrypt/src/encauth/ocb3/ocb3_decrypt_last.c +++ /dev/null @@ -1,110 +0,0 @@ -/* LibTomCrypt, modular cryptographic library -- Tom St Denis - * - * LibTomCrypt is a library that provides various cryptographic - * algorithms in a highly modular and flexible manner. - * - * The library is free for all purposes without any express - * guarantee it works. - */ - -/** - @file ocb3_decrypt_last.c - OCB implementation, internal helper, by Karel Miko -*/ -#include "tomcrypt.h" - -#ifdef LTC_OCB3_MODE - -/** - Finish an OCB (decryption) stream - @param ocb The OCB state - @param ct The remaining ciphertext - @param ctlen The length of the ciphertext (octets) - @param pt [out] The output buffer - @return CRYPT_OK if successful -*/ -int ocb3_decrypt_last(ocb3_state *ocb, const unsigned char *ct, unsigned long ctlen, unsigned char *pt) -{ - unsigned char iOffset_star[MAXBLOCKSIZE]; - unsigned char iPad[MAXBLOCKSIZE]; - int err, x, full_blocks, full_blocks_len, last_block_len; - - LTC_ARGCHK(ocb != NULL); - if (ct == NULL) LTC_ARGCHK(ctlen == 0); - if (ctlen != 0) { - LTC_ARGCHK(ct != NULL); - LTC_ARGCHK(pt != NULL); - } - - if ((err = cipher_is_valid(ocb->cipher)) != CRYPT_OK) { - goto LBL_ERR; - } - - full_blocks = ctlen/ocb->block_len; - full_blocks_len = full_blocks * ocb->block_len; - last_block_len = ctlen - full_blocks_len; - - /* process full blocks first */ - if (full_blocks>0) { - if ((err = ocb3_decrypt(ocb, ct, full_blocks_len, pt)) != CRYPT_OK) { - goto LBL_ERR; - } - } - - if (last_block_len>0) { - /* Offset_* = Offset_m xor L_* */ - ocb3_int_xor_blocks(iOffset_star, ocb->Offset_current, ocb->L_star, ocb->block_len); - - /* Pad = ENCIPHER(K, Offset_*) */ - if ((err = cipher_descriptor[ocb->cipher].ecb_encrypt(iOffset_star, iPad, &ocb->key)) != CRYPT_OK) { - goto LBL_ERR; - } - - /* P_* = C_* xor Pad[1..bitlen(C_*)] */ - ocb3_int_xor_blocks(pt+full_blocks_len, (unsigned char *)ct+full_blocks_len, iPad, last_block_len); - - /* Checksum_* = Checksum_m xor (P_* || 1 || zeros(127-bitlen(P_*))) */ - ocb3_int_xor_blocks(ocb->checksum, ocb->checksum, pt+full_blocks_len, last_block_len); - for(x=last_block_len; xblock_len; x++) { - if (x == last_block_len) - ocb->checksum[x] ^= 0x80; - else - ocb->checksum[x] ^= 0x00; - } - - /* Tag = ENCIPHER(K, Checksum_* xor Offset_* xor L_$) xor HASH(K,A) */ - /* at this point we calculate only: Tag_part = ENCIPHER(K, Checksum_* xor Offset_* xor L_$) */ - for(x=0; xblock_len; x++) { - ocb->tag_part[x] = (ocb->checksum[x] ^ iOffset_star[x]) ^ ocb->L_dollar[x]; - } - if ((err = cipher_descriptor[ocb->cipher].ecb_encrypt(ocb->tag_part, ocb->tag_part, &ocb->key)) != CRYPT_OK) { - goto LBL_ERR; - } - } - else { - /* Tag = ENCIPHER(K, Checksum_m xor Offset_m xor L_$) xor HASH(K,A) */ - /* at this point we calculate only: Tag_part = ENCIPHER(K, Checksum_m xor Offset_m xor L_$) */ - for(x=0; xblock_len; x++) { - ocb->tag_part[x] = (ocb->checksum[x] ^ ocb->Offset_current[x]) ^ ocb->L_dollar[x]; - } - if ((err = cipher_descriptor[ocb->cipher].ecb_encrypt(ocb->tag_part, ocb->tag_part, &ocb->key)) != CRYPT_OK) { - goto LBL_ERR; - } - } - - err = CRYPT_OK; - -LBL_ERR: -#ifdef LTC_CLEAN_STACK - zeromem(iOffset_star, MAXBLOCKSIZE); - zeromem(iPad, MAXBLOCKSIZE); -#endif - - return err; -} - -#endif - -/* ref: $Format:%D$ */ -/* git commit: $Format:%H$ */ -/* commit time: $Format:%ai$ */