diff options
Diffstat (limited to 'openssl/crypto/modes/cts128.c')
| -rw-r--r-- | openssl/crypto/modes/cts128.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/openssl/crypto/modes/cts128.c b/openssl/crypto/modes/cts128.c new file mode 100644 index 000000000..e0430f9fd --- /dev/null +++ b/openssl/crypto/modes/cts128.c @@ -0,0 +1,259 @@ +/* ==================================================================== + * Copyright (c) 2008 The OpenSSL Project. All rights reserved. + * + * Rights for redistribution and usage in source and binary + * forms are granted according to the OpenSSL license. + */ + +#include "modes.h" +#include <string.h> + +#ifndef MODES_DEBUG +# ifndef NDEBUG +# define NDEBUG +# endif +#endif +#include <assert.h> + +/* + * Trouble with Ciphertext Stealing, CTS, mode is that there is no + * common official specification, but couple of cipher/application + * specific ones: RFC2040 and RFC3962. Then there is 'Proposal to + * Extend CBC Mode By "Ciphertext Stealing"' at NIST site, which + * deviates from mentioned RFCs. Most notably it allows input to be + * of block length and it doesn't flip the order of the last two + * blocks. CTS is being discussed even in ECB context, but it's not + * adopted for any known application. This implementation complies + * with mentioned RFCs and [as such] extends CBC mode. + */ + +size_t CRYPTO_cts128_encrypt_block(const unsigned char *in, unsigned char *out, + size_t len, const void *key, + unsigned char ivec[16], block128_f block) +{ size_t residue, n; + + assert (in && out && key && ivec); + + if (len <= 16) return 0; + + if ((residue=len%16) == 0) residue = 16; + + len -= residue; + + CRYPTO_cbc128_encrypt(in,out,len,key,ivec,block); + + in += len; + out += len; + + for (n=0; n<residue; ++n) + ivec[n] ^= in[n]; + (*block)(ivec,ivec,key); + memcpy(out,out-16,residue); + memcpy(out-16,ivec,16); + + return len+residue; +} + +size_t CRYPTO_cts128_encrypt(const unsigned char *in, unsigned char *out, + size_t len, const void *key, + unsigned char ivec[16], cbc128_f cbc) +{ size_t residue; + union { size_t align; unsigned char c[16]; } tmp; + + assert (in && out && key && ivec); + + if (len <= 16) return 0; + + if ((residue=len%16) == 0) residue = 16; + + len -= residue; + + (*cbc)(in,out,len,key,ivec,1); + + in += len; + out += len; + +#if defined(CBC_HANDLES_TRUNCATED_IO) + memcpy(tmp.c,out-16,16); + (*cbc)(in,out-16,residue,key,ivec,1); + memcpy(out,tmp.c,residue); +#else + { + size_t n; + for (n=0; n<16; n+=sizeof(size_t)) + *(size_t *)(tmp.c+n) = 0; + memcpy(tmp.c,in,residue); + } + memcpy(out,out-16,residue); + (*cbc)(tmp.c,out-16,16,key,ivec,1); +#endif + return len+residue; +} + +size_t CRYPTO_cts128_decrypt_block(const unsigned char *in, unsigned char *out, + size_t len, const void *key, + unsigned char ivec[16], block128_f block) +{ size_t residue, n; + union { size_t align; unsigned char c[32]; } tmp; + + assert (in && out && key && ivec); + + if (len<=16) return 0; + + if ((residue=len%16) == 0) residue = 16; + + len -= 16+residue; + + if (len) { + CRYPTO_cbc128_decrypt(in,out,len,key,ivec,block); + in += len; + out += len; + } + + (*block)(in,tmp.c+16,key); + + for (n=0; n<16; n+=sizeof(size_t)) + *(size_t *)(tmp.c+n) = *(size_t *)(tmp.c+16+n); + memcpy(tmp.c,in+16,residue); + (*block)(tmp.c,tmp.c,key); + + for(n=0; n<16; ++n) { + unsigned char c = in[n]; + out[n] = tmp.c[n] ^ ivec[n]; + ivec[n] = c; + } + for(residue+=16; n<residue; ++n) + out[n] = tmp.c[n] ^ in[n]; + + return len+residue-16; +} + +size_t CRYPTO_cts128_decrypt(const unsigned char *in, unsigned char *out, + size_t len, const void *key, + unsigned char ivec[16], cbc128_f cbc) +{ size_t residue, n; + union { size_t align; unsigned char c[32]; } tmp; + + assert (in && out && key && ivec); + + if (len<=16) return 0; + + if ((residue=len%16) == 0) residue = 16; + + len -= 16+residue; + + if (len) { + (*cbc)(in,out,len,key,ivec,0); + in += len; + out += len; + } + + for (n=16; n<32; n+=sizeof(size_t)) + *(size_t *)(tmp.c+n) = 0; + /* this places in[16] at &tmp.c[16] and decrypted block at &tmp.c[0] */ + (*cbc)(in,tmp.c,16,key,tmp.c+16,0); + + memcpy(tmp.c,in+16,residue); +#if defined(CBC_HANDLES_TRUNCATED_IO) + (*cbc)(tmp.c,out,16+residue,key,ivec,0); +#else + (*cbc)(tmp.c,tmp.c,32,key,ivec,0); + memcpy(out,tmp.c,16+residue); +#endif + return len+residue; +} + +#if defined(SELFTEST) +#include <stdio.h> +#include <openssl/aes.h> + +/* test vectors from RFC 3962 */ +static const unsigned char test_key[16] = "chicken teriyaki"; +static const unsigned char test_input[64] = + "I would like the" " General Gau's C" + "hicken, please, " "and wonton soup."; +static const unsigned char test_iv[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + +static const unsigned char vector_17[17] = +{0xc6,0x35,0x35,0x68,0xf2,0xbf,0x8c,0xb4, 0xd8,0xa5,0x80,0x36,0x2d,0xa7,0xff,0x7f, + 0x97}; +static const unsigned char vector_31[31] = +{0xfc,0x00,0x78,0x3e,0x0e,0xfd,0xb2,0xc1, 0xd4,0x45,0xd4,0xc8,0xef,0xf7,0xed,0x22, + 0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5}; +static const unsigned char vector_32[32] = +{0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5,0xa8, + 0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84}; +static const unsigned char vector_47[47] = +{0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84, + 0xb3,0xff,0xfd,0x94,0x0c,0x16,0xa1,0x8c, 0x1b,0x55,0x49,0xd2,0xf8,0x38,0x02,0x9e, + 0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5}; +static const unsigned char vector_48[48] = +{0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84, + 0x9d,0xad,0x8b,0xbb,0x96,0xc4,0xcd,0xc0, 0x3b,0xc1,0x03,0xe1,0xa1,0x94,0xbb,0xd8, + 0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5,0xa8}; +static const unsigned char vector_64[64] = +{0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84, + 0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5,0xa8, + 0x48,0x07,0xef,0xe8,0x36,0xee,0x89,0xa5, 0x26,0x73,0x0d,0xbc,0x2f,0x7b,0xc8,0x40, + 0x9d,0xad,0x8b,0xbb,0x96,0xc4,0xcd,0xc0, 0x3b,0xc1,0x03,0xe1,0xa1,0x94,0xbb,0xd8}; + +static AES_KEY encks, decks; + +void test_vector(const unsigned char *vector,size_t len) +{ unsigned char cleartext[64]; + unsigned char iv[sizeof(test_iv)]; + unsigned char ciphertext[64]; + size_t tail; + + printf("vector_%d\n",len); fflush(stdout); + + if ((tail=len%16) == 0) tail = 16; + tail += 16; + + /* test block-based encryption */ + memcpy(iv,test_iv,sizeof(test_iv)); + CRYPTO_cts128_encrypt_block(test_input,ciphertext,len,&encks,iv,(block128_f)AES_encrypt); + if (memcmp(ciphertext,vector,len)) + fprintf(stderr,"output_%d mismatch\n",len), exit(1); + if (memcmp(iv,vector+len-tail,sizeof(iv))) + fprintf(stderr,"iv_%d mismatch\n",len), exit(1); + + /* test block-based decryption */ + memcpy(iv,test_iv,sizeof(test_iv)); + CRYPTO_cts128_decrypt_block(ciphertext,cleartext,len,&decks,iv,(block128_f)AES_decrypt); + if (memcmp(cleartext,test_input,len)) + fprintf(stderr,"input_%d mismatch\n",len), exit(2); + if (memcmp(iv,vector+len-tail,sizeof(iv))) + fprintf(stderr,"iv_%d mismatch\n",len), exit(2); + + /* test streamed encryption */ + memcpy(iv,test_iv,sizeof(test_iv)); + CRYPTO_cts128_encrypt(test_input,ciphertext,len,&encks,iv,(cbc128_f)AES_cbc_encrypt); + if (memcmp(ciphertext,vector,len)) + fprintf(stderr,"output_%d mismatch\n",len), exit(3); + if (memcmp(iv,vector+len-tail,sizeof(iv))) + fprintf(stderr,"iv_%d mismatch\n",len), exit(3); + + /* test streamed decryption */ + memcpy(iv,test_iv,sizeof(test_iv)); + CRYPTO_cts128_decrypt(ciphertext,cleartext,len,&decks,iv,(cbc128_f)AES_cbc_encrypt); + if (memcmp(cleartext,test_input,len)) + fprintf(stderr,"input_%d mismatch\n",len), exit(4); + if (memcmp(iv,vector+len-tail,sizeof(iv))) + fprintf(stderr,"iv_%d mismatch\n",len), exit(4); +} + +main() +{ + AES_set_encrypt_key(test_key,128,&encks); + AES_set_decrypt_key(test_key,128,&decks); + + test_vector(vector_17,sizeof(vector_17)); + test_vector(vector_31,sizeof(vector_31)); + test_vector(vector_32,sizeof(vector_32)); + test_vector(vector_47,sizeof(vector_47)); + test_vector(vector_48,sizeof(vector_48)); + test_vector(vector_64,sizeof(vector_64)); + exit(0); +} +#endif |