diff options
Diffstat (limited to 'crypto/userspace/libtomcrypt/pk/asn1/der/integer')
3 files changed, 322 insertions, 0 deletions
diff --git a/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_decode_integer.c b/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_decode_integer.c new file mode 100644 index 00000000000..d7b13cfa7c8 --- /dev/null +++ b/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_decode_integer.c @@ -0,0 +1,110 @@ +/* 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. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +/** + @file der_decode_integer.c + ASN.1 DER, decode an integer, Tom St Denis +*/ + + +#ifdef LTC_DER + +/** + Read a mp_int integer + @param in The DER encoded data + @param inlen Size of DER encoded data + @param num The first mp_int to decode + @return CRYPT_OK if successful +*/ +int der_decode_integer(const unsigned char *in, unsigned long inlen, mp_int_t num) +{ + unsigned long x, y, z; + int err; + + LTC_ARGCHK(num != NULL); + LTC_ARGCHK(in != NULL); + + /* min DER INTEGER is 0x02 01 00 == 0 */ + if (inlen < (1 + 1 + 1)) { + return CRYPT_INVALID_PACKET; + } + + /* ok expect 0x02 when we AND with 0001 1111 [1F] */ + x = 0; + if ((in[x++] & 0x1F) != 0x02) { + return CRYPT_INVALID_PACKET; + } + + /* now decode the len stuff */ + z = in[x++]; + + if ((z & 0x80) == 0x00) { + /* short form */ + + /* will it overflow? */ + if (x + z > inlen) { + return CRYPT_INVALID_PACKET; + } + + /* no so read it */ + if ((err = mp_read_unsigned_bin(num, (unsigned char *)in + x, z)) != CRYPT_OK) { + return err; + } + } else { + /* long form */ + z &= 0x7F; + + /* will number of length bytes overflow? (or > 4) */ + if (((x + z) > inlen) || (z > 4) || (z == 0)) { + return CRYPT_INVALID_PACKET; + } + + /* now read it in */ + y = 0; + while (z--) { + y = ((unsigned long)(in[x++])) | (y << 8); + } + + /* now will reading y bytes overrun? */ + if ((x + y) > inlen) { + return CRYPT_INVALID_PACKET; + } + + /* no so read it */ + if ((err = mp_read_unsigned_bin(num, (unsigned char *)in + x, y)) != CRYPT_OK) { + return err; + } + } + + /* see if it's negative */ + if (in[x] & 0x80) { + mp_int tmp; + if (mp_init(&tmp) != CRYPT_OK) { + return CRYPT_MEM; + } + + if (mp_2expt(&tmp, mp_count_bits(num)) != CRYPT_OK || mp_sub(num, &tmp, num) != CRYPT_OK) { + mp_clear(&tmp); + return CRYPT_MEM; + } + mp_clear(&tmp); + } + + return CRYPT_OK; + +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_decode_integer.c,v $ */ +/* $Revision: 1.5 $ */ +/* $Date: 2006/12/28 01:27:24 $ */ diff --git a/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_encode_integer.c b/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_encode_integer.c new file mode 100644 index 00000000000..830446a26cc --- /dev/null +++ b/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_encode_integer.c @@ -0,0 +1,130 @@ +/* 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. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +/** + @file der_encode_integer.c + ASN.1 DER, encode an integer, Tom St Denis +*/ + + +#ifdef LTC_DER + +/* Exports a positive bignum as DER format (upto 2^32 bytes in size) */ +/** + Store a mp_int integer + @param num The first mp_int to encode + @param out [out] The destination for the DER encoded integers + @param outlen [in/out] The max size and resulting size of the DER encoded integers + @return CRYPT_OK if successful +*/ +int der_encode_integer(mp_int_t num, unsigned char *out, unsigned long *outlen) +{ + unsigned long tmplen, y; + int err, leading_zero; + + LTC_ARGCHK(num != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + + /* find out how big this will be */ + if ((err = der_length_integer(num, &tmplen)) != CRYPT_OK) { + return err; + } + + if (*outlen < tmplen) { + *outlen = tmplen; + return CRYPT_BUFFER_OVERFLOW; + } + + if (mp_cmp_d(num, 0) != LTC_MP_LT) { + /* we only need a leading zero if the msb of the first byte is one */ + if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == LTC_MP_YES) { + leading_zero = 1; + } else { + leading_zero = 0; + } + + /* get length of num in bytes (plus 1 since we force the msbyte to zero) */ + y = mp_unsigned_bin_size(num) + leading_zero; + } else { + leading_zero = 0; + y = mp_count_bits(num); + y = y + (8 - (y & 7)); + y = y >> 3; + if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) --y; + } + + /* now store initial data */ + *out++ = 0x02; + if (y < 128) { + /* short form */ + *out++ = (unsigned char)y; + } else if (y < 256) { + *out++ = 0x81; + *out++ = (unsigned char)y; + } else if (y < 65536UL) { + *out++ = 0x82; + *out++ = (unsigned char)((y>>8)&255); + *out++ = (unsigned char)y; + } else if (y < 16777216UL) { + *out++ = 0x83; + *out++ = (unsigned char)((y>>16)&255); + *out++ = (unsigned char)((y>>8)&255); + *out++ = (unsigned char)y; + } else { + return CRYPT_INVALID_ARG; + } + + /* now store msbyte of zero if num is non-zero */ + if (leading_zero) { + *out++ = 0x00; + } + + /* if it's not zero store it as big endian */ + if (mp_cmp_d(num, 0) == LTC_MP_GT) { + /* now store the mpint */ + if ((err = mp_to_unsigned_bin(num, out)) != CRYPT_OK) { + return err; + } + } else if (mp_iszero(num) != LTC_MP_YES) { + mp_int tmp; + + /* negative */ + if (mp_init(&tmp) != CRYPT_OK) { + return CRYPT_MEM; + } + + /* 2^roundup and subtract */ + y = mp_count_bits(num); + y = y + (8 - (y & 7)); + if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) y -= 8; + if (mp_2expt(&tmp, y) != CRYPT_OK || mp_add(&tmp, num, &tmp) != CRYPT_OK) { + mp_clear(&tmp); + return CRYPT_MEM; + } + if ((err = mp_to_unsigned_bin(&tmp, out)) != CRYPT_OK) { + mp_clear(&tmp); + return err; + } + mp_clear(&tmp); + } + + /* we good */ + *outlen = tmplen; + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_encode_integer.c,v $ */ +/* $Revision: 1.9 $ */ +/* $Date: 2006/12/28 01:27:24 $ */ diff --git a/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_length_integer.c b/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_length_integer.c new file mode 100644 index 00000000000..40addd5842b --- /dev/null +++ b/crypto/userspace/libtomcrypt/pk/asn1/der/integer/der_length_integer.c @@ -0,0 +1,82 @@ +/* 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. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +/** + @file der_length_integer.c + ASN.1 DER, get length of encoding, Tom St Denis +*/ + + +#ifdef LTC_DER +/** + Gets length of DER encoding of num + @param num The int to get the size of + @param outlen [out] The length of the DER encoding for the given integer + @return CRYPT_OK if successful +*/ +int der_length_integer(mp_int_t num, unsigned long *outlen) +{ + unsigned long z, len; + int leading_zero; + + LTC_ARGCHK(num != NULL); + LTC_ARGCHK(outlen != NULL); + + if (mp_cmp_d(num, 0) != LTC_MP_LT) { + /* positive */ + + /* we only need a leading zero if the msb of the first byte is one */ + if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == LTC_MP_YES) { + leading_zero = 1; + } else { + leading_zero = 0; + } + + /* size for bignum */ + z = len = leading_zero + mp_unsigned_bin_size(num); + } else { + /* it's negative */ + /* find power of 2 that is a multiple of eight and greater than count bits */ + leading_zero = 0; + z = mp_count_bits(num); + z = z + (8 - (z & 7)); + if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) --z; + len = z = z >> 3; + } + + /* now we need a length */ + if (z < 128) { + /* short form */ + ++len; + } else { + /* long form (relies on z != 0), assumes length bytes < 128 */ + ++len; + + while (z) { + ++len; + z >>= 8; + } + } + + /* we need a 0x02 to indicate it's INTEGER */ + ++len; + + /* return length */ + *outlen = len; + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c,v $ */ +/* $Revision: 1.5 $ */ +/* $Date: 2006/12/28 01:27:24 $ */ |