diff options
| -rw-r--r-- | src/crypto/aes.c | 804 | ||||
| -rw-r--r-- | src/crypto/axtls/aes.c | 457 | ||||
| -rw-r--r-- | src/crypto/axtls_aes.c | 165 | ||||
| -rw-r--r-- | src/include/ipxe/aes.h | 43 | ||||
| -rw-r--r-- | src/include/ipxe/errfile.h | 2 |
5 files changed, 836 insertions, 635 deletions
diff --git a/src/crypto/aes.c b/src/crypto/aes.c new file mode 100644 index 00000000..1605d2ee --- /dev/null +++ b/src/crypto/aes.c @@ -0,0 +1,804 @@ +/* + * Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * You can also choose to distribute this program under the terms of + * the Unmodified Binary Distribution Licence (as given in the file + * COPYING.UBDL), provided that you have satisfied its requirements. + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +/** @file + * + * AES algorithm + * + */ + +#include <stdint.h> +#include <string.h> +#include <errno.h> +#include <assert.h> +#include <byteswap.h> +#include <ipxe/rotate.h> +#include <ipxe/crypto.h> +#include <ipxe/ecb.h> +#include <ipxe/cbc.h> +#include <ipxe/aes.h> + +/** AES strides + * + * These are the strides (modulo 16) used to walk through the AES + * input state bytes in order of byte position after [Inv]ShiftRows. + */ +enum aes_stride { + /** Input stride for ShiftRows + * + * 0 4 8 c + * \ \ \ + * 1 5 9 d + * \ \ \ + * 2 6 a e + * \ \ \ + * 3 7 b f + */ + AES_STRIDE_SHIFTROWS = +5, + /** Input stride for InvShiftRows + * + * 0 4 8 c + * / / / + * 1 5 9 d + * / / / + * 2 6 a e + * / / / + * 3 7 b f + */ + AES_STRIDE_INVSHIFTROWS = -3, +}; + +/** A single AES lookup table entry + * + * This represents the product (in the Galois field GF(2^8)) of an + * eight-byte vector multiplier with a single scalar multiplicand. + * + * The vector multipliers used for AES will be {1,1,1,3,2,1,1,3} for + * MixColumns and {1,9,13,11,14,9,13,11} for InvMixColumns. This + * allows for the result of multiplying any single column of the + * [Inv]MixColumns matrix by a scalar value to be obtained simply by + * extracting the relevant four-byte subset from the lookup table + * entry. + * + * For example, to find the result of multiplying the second column of + * the MixColumns matrix by the scalar value 0x80: + * + * MixColumns column[0]: { 2, 1, 1, 3 } + * MixColumns column[1]: { 3, 2, 1, 1 } + * MixColumns column[2]: { 1, 3, 2, 1 } + * MixColumns column[3]: { 1, 1, 3, 2 } + * Vector multiplier: { 1, 1, 1, 3, 2, 1, 1, 3 } + * Scalar multiplicand: 0x80 + * Lookup table entry: { 0x80, 0x80, 0x80, 0x9b, 0x1b, 0x80, 0x80, 0x9b } + * + * The second column of the MixColumns matrix is {3,2,1,1}. The + * product of this column with the scalar value 0x80 can be obtained + * by extracting the relevant four-byte subset of the lookup table + * entry: + * + * MixColumns column[1]: { 3, 2, 1, 1 } + * Vector multiplier: { 1, 1, 1, 3, 2, 1, 1, 3 } + * Lookup table entry: { 0x80, 0x80, 0x80, 0x9b, 0x1b, 0x80, 0x80, 0x9b } + * Product: { 0x9b, 0x1b, 0x80, 0x80 } + * + * The column lookups require only seven bytes of the eight-byte + * entry: the remaining (first) byte is used to hold the scalar + * multiplicand itself (i.e. the first byte of the vector multiplier + * is always chosen to be 1). + */ +union aes_table_entry { + /** Viewed as an array of bytes */ + uint8_t byte[8]; +} __attribute__ (( packed )); + +/** An AES lookup table + * + * This represents the products (in the Galois field GF(2^8)) of a + * constant eight-byte vector multiplier with all possible 256 scalar + * multiplicands. + * + * The entries are indexed by the AES [Inv]SubBytes S-box output + * values (denoted S(N)). This allows for the result of multiplying + * any single column of the [Inv]MixColumns matrix by S(N) to be + * obtained simply by extracting the relevant four-byte subset from + * the Nth table entry. For example: + * + * Input byte (N): 0x3a + * SubBytes output S(N): 0x80 + * MixColumns column[1]: { 3, 2, 1, 1 } + * Vector multiplier: { 1, 1, 1, 3, 2, 1, 1, 3 } + * Table entry[0x3a]: { 0x80, 0x80, 0x80, 0x9b, 0x1b, 0x80, 0x80, 0x9b } + * Product: { 0x9b, 0x1b, 0x80, 0x80 } + * + * Since the first byte of the eight-byte vector multiplier is always + * chosen to be 1, the value of S(N) may be lookup up by extracting + * the first byte of the Nth table entry. + */ +struct aes_table { + /** Table entries, indexed by S(N) */ + union aes_table_entry entry[256]; +} __attribute__ (( aligned ( 8 ) )); + +/** AES MixColumns lookup table */ +static struct aes_table aes_mixcolumns; + +/** AES InvMixColumns lookup table */ +static struct aes_table aes_invmixcolumns; + +/** + * Multiply [Inv]MixColumns matrix column by scalar multiplicand + * + * @v entry AES lookup table entry for scalar multiplicand + * @v column [Inv]MixColumns matrix column index + * @ret product Product of matrix column with scalar multiplicand + */ +static inline __attribute__ (( always_inline )) uint32_t +aes_entry_column ( const union aes_table_entry *entry, unsigned int column ) { + const uint8_t *first __attribute__ (( may_alias )); + + /* Locate start of relevant four-byte subset */ + first = &entry->byte[ 4 - column ]; + + /* Extract this four-byte subset */ + return ( *( ( uint32_t * ) first ) ); +} + +/** + * Multiply [Inv]MixColumns matrix column by S-boxed input byte + * + * @v table AES lookup table + * @v stride AES row shift stride + * @v in AES input state + * @v offset Output byte offset (after [Inv]ShiftRows) + * @ret product Product of matrix column with S(input byte) + * + * Note that the specified offset is not the offset of the input byte; + * it is the offset of the output byte which corresponds to the input + * byte. This output byte offset is used to calculate both the input + * byte offset and to select the appropriate matric column. + * + * With a compile-time constant offset, this function will optimise + * down to a single "movzbl" (to extract the input byte) and will + * generate a single x86 memory reference expression which can then be + * used directly within a single "xorl" instruction. + */ +static inline __attribute__ (( always_inline )) uint32_t +aes_column ( const struct aes_table *table, size_t stride, + const union aes_matrix *in, size_t offset ) { + const union aes_table_entry *entry; + unsigned int byte; + + /* Extract input byte corresponding to this output byte offset + * (i.e. perform [Inv]ShiftRows). + */ + byte = in->byte[ ( stride * offset ) & 0xf ]; + + /* Locate lookup table entry for this input byte (i.e. perform + * [Inv]SubBytes). + */ + entry = &table->entry[byte]; + + /* Multiply appropriate matrix column by this input byte + * (i.e. perform [Inv]MixColumns). + */ + return aes_entry_column ( entry, ( offset & 0x3 ) ); +} + +/** + * Calculate intermediate round output column + * + * @v table AES lookup table + * @v stride AES row shift stride + * @v in AES input state + * @v key AES round key + * @v column Column index + * @ret output Output column value + */ +static inline __attribute__ (( always_inline )) uint32_t +aes_output ( const struct aes_table *table, size_t stride, + const union aes_matrix *in, const union aes_matrix *key, + unsigned int column ) { + size_t offset = ( column * 4 ); + + /* Perform [Inv]ShiftRows, [Inv]SubBytes, [Inv]MixColumns, and + * AddRoundKey for this column. The loop is unrolled to allow + * for the required compile-time constant optimisations. + */ + return ( aes_column ( table, stride, in, ( offset + 0 ) ) ^ + aes_column ( table, stride, in, ( offset + 1 ) ) ^ + aes_column ( table, stride, in, ( offset + 2 ) ) ^ + aes_column ( table, stride, in, ( offset + 3 ) ) ^ + key->column[column] ); +} + +/** + * Perform a single intermediate round + * + * @v table AES lookup table + * @v stride AES row shift stride + * @v in AES input state + * @v out AES output state + * @v key AES round key + */ +static inline __attribute__ (( always_inline )) void +aes_round ( const struct aes_table *table, size_t stride, + const union aes_matrix *in, union aes_matrix *out, + const union aes_matrix *key ) { + + /* Perform [Inv]ShiftRows, [Inv]SubBytes, [Inv]MixColumns, and + * AddRoundKey for all columns. The loop is unrolled to allow + * for the required compile-time constant optimisations. + */ + out->column[0] = aes_output ( table, stride, in, key, 0 ); + out->column[1] = aes_output ( table, stride, in, key, 1 ); + out->column[2] = aes_output ( table, stride, in, key, 2 ); + out->column[3] = aes_output ( table, stride, in, key, 3 ); +} + +/** + * Perform encryption intermediate rounds + * + * @v in AES input state + * @v out AES output state + * @v key Round keys + * @v rounds Number of rounds (must be odd) + * + * This function is deliberately marked as non-inlinable to ensure + * maximal availability of registers for GCC's register allocator, + * which has a tendency to otherwise spill performance-critical + * registers to the stack. + */ +static __attribute__ (( noinline )) void +aes_encrypt_rounds ( union aes_matrix *in, union aes_matrix *out, + const union aes_matrix *key, unsigned int rounds ) { + union aes_matrix *tmp; + + /* Perform intermediate rounds */ + do { + /* Perform one intermediate round */ + aes_round ( &aes_mixcolumns, AES_STRIDE_SHIFTROWS, + in, out, key++ ); + + /* Swap input and output states for next round */ + tmp = in; + in = out; + out = tmp; + + } while ( --rounds ); +} + +/** + * Perform decryption intermediate rounds + * + * @v in AES input state + * @v out AES output state + * @v key Round keys + * @v rounds Number of rounds (must be odd) + * + * As with aes_encrypt_rounds(), this function is deliberately marked + * as non-inlinable. + * + * This function could potentially use the same binary code as is used + * for encryption. To compensate for the difference between ShiftRows + * and InvShiftRows, half of the input byte offsets would have to be + * modifiable at runtime (half by an offset of +4/-4, half by an + * offset of -4/+4 for ShiftRows/InvShiftRows). This can be + * accomplished in x86 assembly within the number of available + * registers, but GCC's register allocator struggles to do so, + * resulting in a significant performance decrease due to registers + * being spilled to the stack. We therefore use two separate but very + * similar binary functions based on the same C source. + */ +static __attribute__ (( noinline )) void +aes_decrypt_rounds ( union aes_matrix *in, union aes_matrix *out, + const union aes_matrix *key, unsigned int rounds ) { + union aes_matrix *tmp; + + /* Perform intermediate rounds */ + do { + /* Perform one intermediate round */ + aes_round ( &aes_invmixcolumns, AES_STRIDE_INVSHIFTROWS, + in, out, key++ ); + + /* Swap input and output states for next round */ + tmp = in; + in = out; + out = tmp; + + } while ( --rounds ); +} + +/** + * Perform standalone AddRoundKey + * + * @v state AES state + * @v key AES round key + */ +static inline __attribute__ (( always_inline )) void +aes_addroundkey ( union aes_matrix *state, const union aes_matrix *key ) { + + state->column[0] ^= key->column[0]; + state->column[1] ^= key->column[1]; + state->column[2] ^= key->column[2]; + state->column[3] ^= key->column[3]; +} + +/** + * Perform final round + * + * @v table AES lookup table + * @v stride AES row shift stride + * @v in AES input state + * @v out AES output state + * @v key AES round key + */ +static void aes_final ( const struct aes_table *table, size_t stride, + const union aes_matrix *in, union aes_matrix *out, + const union aes_matrix *key ) { + const union aes_table_entry *entry; + unsigned int byte; + size_t out_offset; + size_t in_offset; + + /* Perform [Inv]ShiftRows and [Inv]SubBytes */ + for ( out_offset = 0, in_offset = 0 ; out_offset < 16 ; + out_offset++, in_offset = ( ( in_offset + stride ) & 0xf ) ) { + + /* Extract input byte (i.e. perform [Inv]ShiftRows) */ + byte = in->byte[in_offset]; + + /* Locate lookup table entry for this input byte + * (i.e. perform [Inv]SubBytes). + */ + entry = &table->entry[byte]; + + /* Store output byte */ + out->byte[out_offset] = entry->byte[0]; + } + + /* Perform AddRoundKey */ + aes_addroundkey ( out, key ); +} + +/** + * Encrypt data + * + * @v ctx Context + * @v src Data to encrypt + * @v dst Buffer for encrypted data + * @v len Length of data + */ +static void aes_encrypt ( void *ctx, const void *src, void *dst, size_t len ) { + struct aes_context *aes = ctx; + union aes_matrix buffer[2]; + union aes_matrix *in = &buffer[0]; + union aes_matrix *out = &buffer[1]; + unsigned int rounds = aes->rounds; + + /* Sanity check */ + assert ( len == sizeof ( *in ) ); + + /* Initialise input state */ + memcpy ( in, src, sizeof ( *in ) ); + + /* Perform initial round (AddRoundKey) */ + aes_addroundkey ( in, &aes->encrypt.key[0] ); + + /* Perform intermediate rounds (ShiftRows, SubBytes, + * MixColumns, AddRoundKey). + */ + aes_encrypt_rounds ( in, out, &aes->encrypt.key[1], ( rounds - 2 ) ); + in = out; + + /* Perform final round (ShiftRows, SubBytes, AddRoundKey) */ + out = dst; + aes_final ( &aes_mixcolumns, AES_STRIDE_SHIFTROWS, in, out, + &aes->encrypt.key[ rounds - 1 ] ); +} + +/** + * Decrypt data + * + * @v ctx Context + * @v src Data to decrypt + * @v dst Buffer for decrypted data + * @v len Length of data + */ +static void aes_decrypt ( void *ctx, const void *src, void *dst, size_t len ) { + struct aes_context *aes = ctx; + union aes_matrix buffer[2]; + union aes_matrix *in = &buffer[0]; + union aes_matrix *out = &buffer[1]; + unsigned int rounds = aes->rounds; + + /* Sanity check */ + assert ( len == sizeof ( *in ) ); + + /* Initialise input state */ + memcpy ( in, src, sizeof ( *in ) ); + + /* Perform initial round (AddRoundKey) */ + aes_addroundkey ( in, &aes->decrypt.key[0] ); + + /* Perform intermediate rounds (InvShiftRows, InvSubBytes, + * InvMixColumns, AddRoundKey). + */ + aes_decrypt_rounds ( in, out, &aes->decrypt.key[1], ( rounds - 2 ) ); + in = out; + + /* Perform final round (InvShiftRows, InvSubBytes, AddRoundKey) */ + out = dst; + aes_final ( &aes_invmixcolumns, AES_STRIDE_INVSHIFTROWS, in, out, + &aes->decrypt.key[ rounds - 1 ] ); +} + +/** + * Multiply a polynomial by (x) modulo (x^8 + x^4 + x^3 + x^2 + 1) in GF(2^8) + * + * @v poly Polynomial to be multiplied + * @ret result Result + */ +static __attribute__ (( const )) unsigned int aes_double ( unsigned int poly ) { + + /* Multiply polynomial by (x), placing the resulting x^8 + * coefficient in the LSB (i.e. rotate byte left by one). + */ + poly = rol8 ( poly, 1 ); + + /* If coefficient of x^8 (in LSB) is non-zero, then reduce by + * subtracting (x^8 + x^4 + x^3 + x^2 + 1) in GF(2^8). + */ + if ( poly & 0x01 ) { + poly ^= 0x01; /* Subtract x^8 (currently in LSB) */ + poly ^= 0x1b; /* Subtract (x^4 + x^3 + x^2 + 1) */ + } + + return poly; +} + +/** + * Fill in MixColumns lookup table entry + * + * @v entry AES lookup table entry for scalar multiplicand + * + * The MixColumns lookup table vector multiplier is {1,1,1,3,2,1,1,3}. + */ +static void aes_mixcolumns_entry ( union aes_table_entry *entry ) { + unsigned int scalar_x_1; + unsigned int scalar_x; + unsigned int scalar; + + /* Retrieve scalar multiplicand */ + scalar = entry->byte[0]; + entry->byte[1] = scalar; + entry->byte[2] = scalar; + entry->byte[5] = scalar; + entry->byte[6] = scalar; + + /* Calculate scalar multiplied by (x) */ + scalar_x = aes_double ( scalar ); + entry->byte[4] = scalar_x; + + /* Calculate scalar multiplied by (x + 1) */ + scalar_x_1 = ( scalar_x ^ scalar ); + entry->byte[3] = scalar_x_1; + entry->byte[7] = scalar_x_1; +} + +/** + * Fill in InvMixColumns lookup table entry + * + * @v entry AES lookup table entry for scalar multiplicand + * + * The InvMixColumns lookup table vector multiplier is {1,9,13,11,14,9,13,11}. + */ +static void aes_invmixcolumns_entry ( union aes_table_entry *entry ) { + unsigned int scalar_x3_x2_x; + unsigned int scalar_x3_x2_1; + unsigned int scalar_x3_x2; + unsigned int scalar_x3_x_1; + unsigned int scalar_x3_1; + unsigned int scalar_x3; + unsigned int scalar_x2; + unsigned int scalar_x; + unsigned int scalar; + + /* Retrieve scalar multiplicand */ + scalar = entry->byte[0]; + + /* Calculate scalar multiplied by (x) */ + scalar_x = aes_double ( scalar ); + + /* Calculate scalar multiplied by (x^2) */ + scalar_x2 = aes_double ( scalar_x ); + + /* Calculate scalar multiplied by (x^3) */ + scalar_x3 = aes_double ( scalar_x2 ); + + /* Calculate scalar multiplied by (x^3 + 1) */ + scalar_x3_1 = ( scalar_x3 ^ scalar ); + entry->byte[1] = scalar_x3_1; + entry->byte[5] = scalar_x3_1; + + /* Calculate scalar multiplied by (x^3 + x + 1) */ + scalar_x3_x_1 = ( scalar_x3_1 ^ scalar_x ); + entry->byte[3] = scalar_x3_x_1; + entry->byte[7] = scalar_x3_x_1; + + /* Calculate scalar multiplied by (x^3 + x^2) */ + scalar_x3_x2 = ( scalar_x3 ^ scalar_x2 ); + + /* Calculate scalar multiplied by (x^3 + x^2 + 1) */ + scalar_x3_x2_1 = ( scalar_x3_x2 ^ scalar ); + entry->byte[2] = scalar_x3_x2_1; + entry->byte[6] = scalar_x3_x2_1; + + /* Calculate scalar multiplied by (x^3 + x^2 + x) */ + scalar_x3_x2_x = ( scalar_x3_x2 ^ scalar_x ); + entry->byte[4] = scalar_x3_x2_x; +} + +/** + * Generate AES lookup tables + * + */ +static void aes_generate ( void ) { + union aes_table_entry *entry; + union aes_table_entry *inventry; + unsigned int poly = 0x01; + unsigned int invpoly = 0x01; + unsigned int transformed; + unsigned int i; + + /* Iterate over non-zero values of GF(2^8) using generator (x + 1) */ + do { + + /* Multiply polynomial by (x + 1) */ + poly ^= aes_double ( poly ); + + /* Divide inverse polynomial by (x + 1). This code + * fragment is taken directly from the Wikipedia page + * on the Rijndael S-box. An explanation of why it + * works would be greatly appreciated. + */ + invpoly ^= ( invpoly << 1 ); + invpoly ^= ( invpoly << 2 ); + invpoly ^= ( invpoly << 4 ); + if ( invpoly & 0x80 ) + invpoly ^= 0x09; + invpoly &= 0xff; + + /* Apply affine transformation */ + transformed = ( 0x63 ^ invpoly ^ rol8 ( invpoly, 1 ) ^ + rol8 ( invpoly, 2 ) ^ rol8 ( invpoly, 3 ) ^ + rol8 ( invpoly, 4 ) ); + + /* Populate S-box (within MixColumns lookup table) */ + aes_mixcolumns.entry[poly].byte[0] = transformed; + + } while ( poly != 0x01 ); + + /* Populate zeroth S-box entry (which has no inverse) */ + aes_mixcolumns.entry[0].byte[0] = 0x63; + + /* Fill in MixColumns and InvMixColumns lookup tables */ + for ( i = 0 ; i < 256 ; i++ ) { + + /* Fill in MixColumns lookup table entry */ + entry = &aes_mixcolumns.entry[i]; + aes_mixcolumns_entry ( entry ); + + /* Populate inverse S-box (within InvMixColumns lookup table) */ + inventry = &aes_invmixcolumns.entry[ entry->byte[0] ]; + inventry->byte[0] = i; + + /* Fill in InvMixColumns lookup table entry */ + aes_invmixcolumns_entry ( inventry ); + } +} + +/** + * Rotate key column + * + * @v column Key column + * @ret column Updated key column + */ +static inline __attribute__ (( always_inline )) uint32_t +aes_key_rotate ( uint32_t column ) { + + return ( ( __BYTE_ORDER == __LITTLE_ENDIAN ) ? + ror32 ( column, 8 ) : rol32 ( column, 8 ) ); +} + +/** + * Apply S-box to key column + * + * @v column Key column + * @ret column Updated key column + */ +static uint32_t aes_key_sbox ( uint32_t column ) { + unsigned int i; + uint8_t byte; + + for ( i = 0 ; i < 4 ; i++ ) { + byte = ( column & 0xff ); + byte = aes_mixcolumns.entry[byte].byte[0]; + column = ( ( column & ~0xff ) | byte ); + column = rol32 ( column, 8 ); + } + return column; +} + +/** + * Apply schedule round constant to key column + * + * @v column Key column + * @v rcon Round constant + * @ret column Updated key column + */ +static inline __attribute__ (( always_inline )) uint32_t +aes_key_rcon ( uint32_t column, unsigned int rcon ) { + + return ( ( __BYTE_ORDER == __LITTLE_ENDIAN ) ? + ( column ^ rcon ) : ( column ^ ( rcon << 24 ) ) ); +} + +/** + * Set key + * + * @v ctx Context + * @v key Key + * @v keylen Key length + * @ret rc Return status code + */ +static int aes_setkey ( void *ctx, const void *key, size_t keylen ) { + struct aes_context *aes = ctx; + union aes_matrix *enc; + union aes_matrix *dec; + union aes_matrix temp; + union aes_matrix zero; + unsigned int rcon = 0x01; + unsigned int rounds; + size_t offset = 0; + uint32_t *prev; + uint32_t *next; + uint32_t *end; + uint32_t tmp; + + /* Generate lookup tables, if not already done */ + if ( ! aes_mixcolumns.entry[0].byte[0] ) + aes_generate(); + + /* Validate key length and calculate number of intermediate rounds */ + switch ( keylen ) { + case ( 128 / 8 ) : + rounds = 11; + break; + case ( 192 / 8 ) : + rounds = 13; + break; + case ( 256 / 8 ) : + rounds = 15; + break; + default: + DBGC ( aes, "AES %p unsupported key length (%zd bits)\n", + aes, ( keylen * 8 ) ); + return -EINVAL; + } + aes->rounds = rounds; + enc = aes->encrypt.key; + end = enc[rounds].column; + + /* Copy raw key */ + memcpy ( enc, key, keylen ); + prev = enc->column; + next = ( ( ( void * ) prev ) + keylen ); + tmp = next[-1]; + + /* Construct expanded key */ + while ( next < end ) { + + /* If this is the first column of an expanded key + * block, or the middle column of an AES-256 key + * block, then apply the S-box. + */ + if ( ( offset == 0 ) || ( ( offset | keylen ) == 48 ) ) + tmp = aes_key_sbox ( tmp ); + + /* If this is the first column of an expanded key + * block then rotate and apply the round constant. + */ + if ( offset == 0 ) { + tmp = aes_key_rotate ( tmp ); + tmp = aes_key_rcon ( tmp, rcon ); + rcon = aes_double ( rcon ); + } + + /* XOR with previous key column */ + tmp ^= *prev; + + /* Store column */ + *next = tmp; + + /* Move to next column */ + offset += sizeof ( *next ); + if ( offset == keylen ) + offset = 0; + next++; + prev++; + } + DBGC2 ( aes, "AES %p expanded %zd-bit key:\n", aes, ( keylen * 8 ) ); + DBGC2_HDA ( aes, 0, &aes->encrypt, ( rounds * sizeof ( *enc ) ) ); + + /* Convert to decryption key */ + memset ( &zero, 0, sizeof ( zero ) ); + dec = &aes->decrypt.key[ rounds - 1 ]; + memcpy ( dec--, enc++, sizeof ( *dec ) ); + while ( dec > aes->decrypt.key ) { + /* Perform InvMixColumns (by reusing the encryption + * final-round code to perform ShiftRows+SubBytes and + * reusing the decryption intermediate-round code to + * perform InvShiftRows+InvSubBytes+InvMixColumns, all + * with a zero encryption key). + */ + aes_final ( &aes_mixcolumns, AES_STRIDE_SHIFTROWS, + enc++, &temp, &zero ); + aes_decrypt_rounds ( &temp, dec--, &zero, 1 ); + } + memcpy ( dec--, enc++, sizeof ( *dec ) ); + DBGC2 ( aes, "AES %p inverted %zd-bit key:\n", aes, ( keylen * 8 ) ); + DBGC2_HDA ( aes, 0, &aes->decrypt, ( rounds * sizeof ( *dec ) ) ); + + return 0; +} + +/** + * Set initialisation vector + * + * @v ctx Context + * @v iv Initialisation vector + */ +static void aes_setiv ( void *ctx __unused, const void *iv __unused ) { + /* Nothing to do */ +} + +/** Basic AES algorithm */ +struct cipher_algorithm aes_algorithm = { + .name = "aes", + .ctxsize = sizeof ( struct aes_context ), + .blocksize = AES_BLOCKSIZE, + .setkey = aes_setkey, + .setiv = aes_setiv, + .encrypt = aes_encrypt, + .decrypt = aes_decrypt, +}; + +/* AES in Electronic Codebook mode */ +ECB_CIPHER ( aes_ecb, aes_ecb_algorithm, + aes_algorithm, struct aes_context, AES_BLOCKSIZE ); + +/* AES in Cipher Block Chaining mode */ +CBC_CIPHER ( aes_cbc, aes_cbc_algorithm, + aes_algorithm, struct aes_context, AES_BLOCKSIZE ); diff --git a/src/crypto/axtls/aes.c b/src/crypto/axtls/aes.c deleted file mode 100644 index bd99a709..00000000 --- a/src/crypto/axtls/aes.c +++ /dev/null @@ -1,457 +0,0 @@ -/* - * Copyright (c) 2007, Cameron Rich - * - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * * Redistributions of source code must retain the above copyright notice, - * this list of conditions and the following disclaimer. - * * 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. - * * Neither the name of the axTLS project nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "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 COPYRIGHT OWNER 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. - */ - -/** - * AES implementation - this is a small code version. There are much faster - * versions around but they are much larger in size (i.e. they use large - * submix tables). - */ - -#include <string.h> -#include "os_port.h" -#include "crypto.h" - -/* all commented out in skeleton mode */ -#ifndef CONFIG_SSL_SKELETON_MODE - -#define rot1(x) (((x) << 24) | ((x) >> 8)) -#define rot2(x) (((x) << 16) | ((x) >> 16)) -#define rot3(x) (((x) << 8) | ((x) >> 24)) - -/* - * This cute trick does 4 'mul by two' at once. Stolen from - * Dr B. R. Gladman <brg@gladman.uk.net> but I'm sure the u-(u>>7) is - * a standard graphics trick - * The key to this is that we need to xor with 0x1b if the top bit is set. - * a 1xxx xxxx 0xxx 0xxx First we mask the 7bit, - * b 1000 0000 0000 0000 then we shift right by 7 putting the 7bit in 0bit, - * c 0000 0001 0000 0000 we then subtract (c) from (b) - * d 0111 1111 0000 0000 and now we and with our mask - * e 0001 1011 0000 0000 - */ -#define mt 0x80808080 -#define ml 0x7f7f7f7f -#define mh 0xfefefefe -#define mm 0x1b1b1b1b -#define mul2(x,t) ((t)=((x)&mt), \ - ((((x)+(x))&mh)^(((t)-((t)>>7))&mm))) - -#define inv_mix_col(x,f2,f4,f8,f9) (\ - (f2)=mul2(x,f2), \ - (f4)=mul2(f2,f4), \ - (f8)=mul2(f4,f8), \ - (f9)=(x)^(f8), \ - (f8)=((f2)^(f4)^(f8)), \ - (f2)^=(f9), \ - (f4)^=(f9), \ - (f8)^=rot3(f2), \ - (f8)^=rot2(f4), \ - (f8)^rot1(f9)) - -/* - * AES S-box - */ -static const uint8_t aes_sbox[256] = -{ - 0x63,0x7C,0x77,0x7B,0xF2,0x6B,0x6F,0xC5, - 0x30,0x01,0x67,0x2B,0xFE,0xD7,0xAB,0x76, - 0xCA,0x82,0xC9,0x7D,0xFA,0x59,0x47,0xF0, - 0xAD,0xD4,0xA2,0xAF,0x9C,0xA4,0x72,0xC0, - 0xB7,0xFD,0x93,0x26,0x36,0x3F,0xF7,0xCC, - 0x34,0xA5,0xE5,0xF1,0x71,0xD8,0x31,0x15, - 0x04,0xC7,0x23,0xC3,0x18,0x96,0x05,0x9A, - 0x07,0x12,0x80,0xE2,0xEB,0x27,0xB2,0x75, - 0x09,0x83,0x2C,0x1A,0x1B,0x6E,0x5A,0xA0, - 0x52,0x3B,0xD6,0xB3,0x29,0xE3,0x2F,0x84, - 0x53,0xD1,0x00,0xED,0x20,0xFC,0xB1,0x5B, - 0x6A,0xCB,0xBE,0x39,0x4A,0x4C,0x58,0xCF, - 0xD0,0xEF,0xAA,0xFB,0x43,0x4D,0x33,0x85, - 0x45,0xF9,0x02,0x7F,0x50,0x3C,0x9F,0xA8, - 0x51,0xA3,0x40,0x8F,0x92,0x9D,0x38,0xF5, - 0xBC,0xB6,0xDA,0x21,0x10,0xFF,0xF3,0xD2, - 0xCD,0x0C,0x13,0xEC,0x5F,0x97,0x44,0x17, - 0xC4,0xA7,0x7E,0x3D,0x64,0x5D,0x19,0x73, - 0x60,0x81,0x4F,0xDC,0x22,0x2A,0x90,0x88, - 0x46,0xEE,0xB8,0x14,0xDE,0x5E,0x0B,0xDB, - 0xE0,0x32,0x3A,0x0A,0x49,0x06,0x24,0x5C, - 0xC2,0xD3,0xAC,0x62,0x91,0x95,0xE4,0x79, - 0xE7,0xC8,0x37,0x6D,0x8D,0xD5,0x4E,0xA9, - 0x6C,0x56,0xF4,0xEA,0x65,0x7A,0xAE,0x08, - 0xBA,0x78,0x25,0x2E,0x1C,0xA6,0xB4,0xC6, - 0xE8,0xDD,0x74,0x1F,0x4B,0xBD,0x8B,0x8A, - 0x70,0x3E,0xB5,0x66,0x48,0x03,0xF6,0x0E, - 0x61,0x35,0x57,0xB9,0x86,0xC1,0x1D,0x9E, - 0xE1,0xF8,0x98,0x11,0x69,0xD9,0x8E,0x94, - 0x9B,0x1E,0x87,0xE9,0xCE,0x55,0x28,0xDF, - 0x8C,0xA1,0x89,0x0D,0xBF,0xE6,0x42,0x68, - 0x41,0x99,0x2D,0x0F,0xB0,0x54,0xBB,0x16, -}; - -/* - * AES is-box - */ -static const uint8_t aes_isbox[256] = -{ - 0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38, - 0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb, - 0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87, - 0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb, - 0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d, - 0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e, - 0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2, - 0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25, - 0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16, - 0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92, - 0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda, - 0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84, - 0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a, - 0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06, - 0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02, - 0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b, - 0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea, - 0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73, - 0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85, - 0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e, - 0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89, - 0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b, - 0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20, - 0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4, - 0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31, - 0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f, - 0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d, - 0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef, - 0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0, - 0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61, - 0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26, - 0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d -}; - -static const unsigned char Rcon[30]= -{ - 0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80, - 0x1b,0x36,0x6c,0xd8,0xab,0x4d,0x9a,0x2f, - 0x5e,0xbc,0x63,0xc6,0x97,0x35,0x6a,0xd4, - 0xb3,0x7d,0xfa,0xef,0xc5,0x91, -}; - -/* ----- static functions ----- */ -static void AES_encrypt(const AES_CTX *ctx, uint32_t *data); -static void AES_decrypt(const AES_CTX *ctx, uint32_t *data); - -/* Perform doubling in Galois Field GF(2^8) using the irreducible polynomial - x^8+x^4+x^3+x+1 */ -static unsigned char AES_xtime(uint32_t x) -{ - return (x&0x80) ? (x<<1)^0x1b : x<<1; -} - -/** - * Set up AES with the key/iv and cipher size. - */ -void AES_set_key(AES_CTX *ctx, const uint8_t *key, - const uint8_t *iv, AES_MODE mode) -{ - int i, ii; - uint32_t *W, tmp, tmp2; - const unsigned char *ip; - int words; - - switch (mode) - { - case AES_MODE_128: - i = 10; - words = 4; - break; - - case AES_MODE_256: - i = 14; - words = 8; - break; - - default: /* fail silently */ - return; - } - - ctx->rounds = i; - ctx->key_size = words; - W = ctx->ks; - for (i = 0; i < words; i+=2) - { - W[i+0]= ((uint32_t)key[ 0]<<24)| - ((uint32_t)key[ 1]<<16)| - ((uint32_t)key[ 2]<< 8)| - ((uint32_t)key[ 3] ); - W[i+1]= ((uint32_t)key[ 4]<<24)| - ((uint32_t)key[ 5]<<16)| - ((uint32_t)key[ 6]<< 8)| - ((uint32_t)key[ 7] ); - key += 8; - } - - ip = Rcon; - ii = 4 * (ctx->rounds+1); - for (i = words; i<ii; i++) - { - tmp = W[i-1]; - - if ((i % words) == 0) - { - tmp2 =(uint32_t)aes_sbox[(tmp )&0xff]<< 8; - tmp2|=(uint32_t)aes_sbox[(tmp>> 8)&0xff]<<16; - tmp2|=(uint32_t)aes_sbox[(tmp>>16)&0xff]<<24; - tmp2|=(uint32_t)aes_sbox[(tmp>>24) ]; - tmp=tmp2^(((unsigned int)*ip)<<24); - ip++; - } - - if ((words == 8) && ((i % words) == 4)) - { - tmp2 =(uint32_t)aes_sbox[(tmp )&0xff] ; - tmp2|=(uint32_t)aes_sbox[(tmp>> 8)&0xff]<< 8; - tmp2|=(uint32_t)aes_sbox[(tmp>>16)&0xff]<<16; - tmp2|=(uint32_t)aes_sbox[(tmp>>24) ]<<24; - tmp=tmp2; - } - - W[i]=W[i-words]^tmp; - } - - /* copy the iv across */ - memcpy(ctx->iv, iv, 16); -} - -/** - * Change a key for decryption. - */ -void AES_convert_key(AES_CTX *ctx) -{ - int i; - uint32_t *k,w,t1,t2,t3,t4; - - k = ctx->ks; - k += 4; - - for (i= ctx->rounds*4; i > 4; i--) - { - w= *k; - w = inv_mix_col(w,t1,t2,t3,t4); - *k++ =w; - } -} - -/** - * Encrypt a byte sequence (with a block size 16) using the AES cipher. - */ -void AES_cbc_encrypt(AES_CTX *ctx, const uint8_t *msg, uint8_t *out, int length) -{ - int i; - uint32_t tin[4], tout[4], iv[4]; - - memcpy(iv, ctx->iv, AES_IV_SIZE); - for (i = 0; i < 4; i++) - tout[i] = ntohl(iv[i]); - - for (length -= AES_BLOCKSIZE; length >= 0; length -= AES_BLOCKSIZE) - { - uint32_t msg_32[4]; - uint32_t out_32[4]; - memcpy(msg_32, msg, AES_BLOCKSIZE); - msg += AES_BLOCKSIZE; - - for (i = 0; i < 4; i++) - tin[i] = ntohl(msg_32[i])^tout[i]; - - AES_encrypt(ctx, tin); - - for (i = 0; i < 4; i++) - { - tout[i] = tin[i]; - out_32[i] = htonl(tout[i]); - } - - memcpy(out, out_32, AES_BLOCKSIZE); - out += AES_BLOCKSIZE; - } - - for (i = 0; i < 4; i++) - iv[i] = htonl(tout[i]); - memcpy(ctx->iv, iv, AES_IV_SIZE); -} - -/** - * Decrypt a byte sequence (with a block size 16) using the AES cipher. - */ -void AES_cbc_decrypt(AES_CTX *ctx, const uint8_t *msg, uint8_t *out, int length) -{ - int i; - uint32_t tin[4], xor[4], tout[4], data[4], iv[4]; - - memcpy(iv, ctx->iv, AES_IV_SIZE); - for (i = 0; i < 4; i++) - xor[i] = ntohl(iv[i]); - - for (length -= 16; length >= 0; length -= 16) - { - uint32_t msg_32[4]; - uint32_t out_32[4]; - memcpy(msg_32, msg, AES_BLOCKSIZE); - msg += AES_BLOCKSIZE; - - for (i = 0; i < 4; i++) - { - tin[i] = ntohl(msg_32[i]); - data[i] = tin[i]; - } - - AES_decrypt(ctx, data); - - for (i = 0; i < 4; i++) - { - tout[i] = data[i]^xor[i]; - xor[i] = tin[i]; - out_32[i] = htonl(tout[i]); - } - - memcpy(out, out_32, AES_BLOCKSIZE); - out += AES_BLOCKSIZE; - } - - for (i = 0; i < 4; i++) - iv[i] = htonl(xor[i]); - memcpy(ctx->iv, iv, AES_IV_SIZE); -} - -/** - * Encrypt a single block (16 bytes) of data - */ -static void AES_encrypt(const AES_CTX *ctx, uint32_t *data) -{ - /* To make this code smaller, generate the sbox entries on the fly. - * This will have a really heavy effect upon performance. - */ - uint32_t tmp[4]; - uint32_t tmp1, old_a0, a0, a1, a2, a3, row; - int curr_rnd; - int rounds = ctx->rounds; - const uint32_t *k = ctx->ks; - - /* Pre-round key addition */ - for (row = 0; row < 4; row++) - data[row] ^= *(k++); - - /* Encrypt one block. */ - for (curr_rnd = 0; curr_rnd < rounds; curr_rnd++) - { - /* Perform ByteSub and ShiftRow operations together */ - for (row = 0; row < 4; row++) - { - a0 = (uint32_t)aes_sbox[(data[row%4]>>24)&0xFF]; - a1 = (uint32_t)aes_sbox[(data[(row+1)%4]>>16)&0xFF]; - a2 = (uint32_t)aes_sbox[(data[(row+2)%4]>>8)&0xFF]; - a3 = (uint32_t)aes_sbox[(data[(row+3)%4])&0xFF]; - - /* Perform MixColumn iff not last round */ - if (curr_rnd < (rounds - 1)) - { - tmp1 = a0 ^ a1 ^ a2 ^ a3; - old_a0 = a0; - a0 ^= tmp1 ^ AES_xtime(a0 ^ a1); - a1 ^= tmp1 ^ AES_xtime(a1 ^ a2); - a2 ^= tmp1 ^ AES_xtime(a2 ^ a3); - a3 ^= tmp1 ^ AES_xtime(a3 ^ old_a0); - } - - tmp[row] = ((a0 << 24) | (a1 << 16) | (a2 << 8) | a3); - } - - /* KeyAddition - note that it is vital that this loop is separate from - the MixColumn operation, which must be atomic...*/ - for (row = 0; row < 4; row++) - data[row] = tmp[row] ^ *(k++); - } -} - -/** - * Decrypt a single block (16 bytes) of data - */ -static void AES_decrypt(const AES_CTX *ctx, uint32_t *data) -{ - uint32_t tmp[4]; - uint32_t xt0,xt1,xt2,xt3,xt4,xt5,xt6; - uint32_t a0, a1, a2, a3, row; - int curr_rnd; - int rounds = ctx->rounds; - const uint32_t *k = ctx->ks + ((rounds+1)*4); - - /* pre-round key addition */ - for (row=4; row > 0;row--) - data[row-1] ^= *(--k); - - /* Decrypt one block */ - for (curr_rnd = 0; curr_rnd < rounds; curr_rnd++) - { - /* Perform ByteSub and ShiftRow operations together */ - for (row = 4; row > 0; row--) - { - a0 = aes_isbox[(data[(row+3)%4]>>24)&0xFF]; - a1 = aes_isbox[(data[(row+2)%4]>>16)&0xFF]; - a2 = aes_isbox[(data[(row+1)%4]>>8)&0xFF]; - a3 = aes_isbox[(data[row%4])&0xFF]; - - /* Perform MixColumn iff not last round */ - if (curr_rnd<(rounds-1)) - { - /* The MDS cofefficients (0x09, 0x0B, 0x0D, 0x0E) - are quite large compared to encryption; this - operation slows decryption down noticeably. */ - xt0 = AES_xtime(a0^a1); - xt1 = AES_xtime(a1^a2); - xt2 = AES_xtime(a2^a3); - xt3 = AES_xtime(a3^a0); - xt4 = AES_xtime(xt0^xt1); - xt5 = AES_xtime(xt1^xt2); - xt6 = AES_xtime(xt4^xt5); - - xt0 ^= a1^a2^a3^xt4^xt6; - xt1 ^= a0^a2^a3^xt5^xt6; - xt2 ^= a0^a1^a3^xt4^xt6; - xt3 ^= a0^a1^a2^xt5^xt6; - tmp[row-1] = ((xt0<<24)|(xt1<<16)|(xt2<<8)|xt3); - } - else - tmp[row-1] = ((a0<<24)|(a1<<16)|(a2<<8)|a3); - } - - for (row = 4; row > 0; row--) - data[row-1] = tmp[row-1] ^ *(--k); - } -} - -#endif diff --git a/src/crypto/axtls_aes.c b/src/crypto/axtls_aes.c deleted file mode 100644 index 9d6b6459..00000000 --- a/src/crypto/axtls_aes.c +++ /dev/null @@ -1,165 +0,0 @@ -/* - * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301, USA. - */ - -FILE_LICENCE ( GPL2_OR_LATER ); - -#include <string.h> -#include <errno.h> -#include <assert.h> -#include <byteswap.h> -#include <ipxe/crypto.h> -#include <ipxe/ecb.h> -#include <ipxe/cbc.h> -#include <ipxe/aes.h> -#include "crypto/axtls/crypto.h" - -/** @file - * - * AES algorithm - * - */ - -/** - * Set key - * - * @v ctx Context - * @v key Key - * @v keylen Key length - * @ret rc Return status code - */ -static int aes_setkey ( void *ctx, const void *key, size_t keylen ) { - struct aes_context *aes_ctx = ctx; - AES_MODE mode; - void *iv; - - switch ( keylen ) { - case ( 128 / 8 ): - mode = AES_MODE_128; - break; - case ( 256 / 8 ): - mode = AES_MODE_256; - break; - default: - return -EINVAL; - } - - /* IV is not a relevant concept at this stage; use a dummy - * value that will have no side-effects. - */ - iv = &aes_ctx->axtls_ctx.iv; - - AES_set_key ( &aes_ctx->axtls_ctx, key, iv, mode ); - - aes_ctx->decrypting = 0; - - return 0; -} - -/** - * Set initialisation vector - * - * @v ctx Context - * @v iv Initialisation vector - */ -static void aes_setiv ( void *ctx __unused, const void *iv __unused ) { - /* Nothing to do */ -} - -/** - * Call AXTLS' AES_encrypt() or AES_decrypt() functions - * - * @v axtls_ctx AXTLS AES context - * @v src Data to process - * @v dst Buffer for output - * @v func AXTLS AES function to call - */ -static void aes_call_axtls ( AES_CTX *axtls_ctx, const void *src, void *dst, - void ( * func ) ( const AES_CTX *axtls_ctx, - uint32_t *data ) ){ - const uint32_t *srcl = src; - uint32_t *dstl = dst; - unsigned int i; - - /* AXTLS' AES_encrypt() and AES_decrypt() functions both - * expect to deal with an array of four dwords in host-endian - * order. - */ - for ( i = 0 ; i < 4 ; i++ ) - dstl[i] = ntohl ( srcl[i] ); - func ( axtls_ctx, dstl ); - for ( i = 0 ; i < 4 ; i++ ) - dstl[i] = htonl ( dstl[i] ); -} - -/** - * Encrypt data - * - * @v ctx Context - * @v src Data to encrypt - * @v dst Buffer for encrypted data - * @v len Length of data - */ -static void aes_encrypt ( void *ctx, const void *src, void *dst, - size_t len ) { - struct aes_context *aes_ctx = ctx; - - assert ( len == AES_BLOCKSIZE ); - if ( aes_ctx->decrypting ) - assert ( 0 ); - aes_call_axtls ( &aes_ctx->axtls_ctx, src, dst, axtls_aes_encrypt ); -} - -/** - * Decrypt data - * - * @v ctx Context - * @v src Data to decrypt - * @v dst Buffer for decrypted data - * @v len Length of data - */ -static void aes_decrypt ( void *ctx, const void *src, void *dst, - size_t len ) { - struct aes_context *aes_ctx = ctx; - - assert ( len == AES_BLOCKSIZE ); - if ( ! aes_ctx->decrypting ) { - AES_convert_key ( &aes_ctx->axtls_ctx ); - aes_ctx->decrypting = 1; - } - aes_call_axtls ( &aes_ctx->axtls_ctx, src, dst, axtls_aes_decrypt ); -} - -/** Basic AES algorithm */ -struct cipher_algorithm aes_algorithm = { - .name = "aes", - .ctxsize = sizeof ( struct aes_context ), - .blocksize = AES_BLOCKSIZE, - .setkey = aes_setkey, - .setiv = aes_setiv, - .encrypt = aes_encrypt, - .decrypt = aes_decrypt, -}; - -/* AES in Electronic Codebook mode */ -ECB_CIPHER ( aes_ecb, aes_ecb_algorithm, - aes_algorithm, struct aes_context, AES_BLOCKSIZE ); - -/* AES in Cipher Block Chaining mode */ -CBC_CIPHER ( aes_cbc, aes_cbc_algorithm, - aes_algorithm, struct aes_context, AES_BLOCKSIZE ); diff --git a/src/include/ipxe/aes.h b/src/include/ipxe/aes.h index 91e7483a..0432e43e 100644 --- a/src/include/ipxe/aes.h +++ b/src/include/ipxe/aes.h @@ -1,30 +1,49 @@ #ifndef _IPXE_AES_H #define _IPXE_AES_H -FILE_LICENCE ( GPL2_OR_LATER ); +/** @file + * + * AES algorithm + * + */ -struct cipher_algorithm; +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); -/** Basic AES blocksize */ +#include <ipxe/crypto.h> + +/** AES blocksize */ #define AES_BLOCKSIZE 16 -#include "crypto/axtls/crypto.h" +/** Maximum number of AES rounds */ +#define AES_MAX_ROUNDS 15 + +/** AES matrix */ +union aes_matrix { + /** Viewed as an array of bytes */ + uint8_t byte[16]; + /** Viewed as an array of four-byte columns */ + uint32_t column[4]; +} __attribute__ (( packed )); + +/** AES round keys */ +struct aes_round_keys { + /** Round keys */ + union aes_matrix key[AES_MAX_ROUNDS]; +}; /** AES context */ struct aes_context { - /** AES context for AXTLS */ - AES_CTX axtls_ctx; - /** Cipher is being used for decrypting */ - int decrypting; + /** Encryption keys */ + struct aes_round_keys encrypt; + /** Decryption keys */ + struct aes_round_keys decrypt; + /** Number of rounds */ + unsigned int rounds; }; /** AES context size */ #define AES_CTX_SIZE sizeof ( struct aes_context ) -/* AXTLS functions */ -extern void axtls_aes_encrypt ( const AES_CTX *ctx, uint32_t *data ); -extern void axtls_aes_decrypt ( const AES_CTX *ctx, uint32_t *data ); - extern struct cipher_algorithm aes_algorithm; extern struct cipher_algorithm aes_ecb_algorithm; extern struct cipher_algorithm aes_cbc_algorithm; diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h index 6553cd87..de50fab9 100644 --- a/src/include/ipxe/errfile.h +++ b/src/include/ipxe/errfile.h @@ -264,7 +264,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #define ERRFILE_imgmgmt ( ERRFILE_OTHER | 0x00050000 ) #define ERRFILE_pxe_tftp ( ERRFILE_OTHER | 0x00060000 ) #define ERRFILE_pxe_udp ( ERRFILE_OTHER | 0x00070000 ) -#define ERRFILE_axtls_aes ( ERRFILE_OTHER | 0x00080000 ) +#define ERRFILE_aes ( ERRFILE_OTHER | 0x00080000 ) #define ERRFILE_cipher ( ERRFILE_OTHER | 0x00090000 ) #define ERRFILE_image_cmd ( ERRFILE_OTHER | 0x000a0000 ) #define ERRFILE_uri_test ( ERRFILE_OTHER | 0x000b0000 ) |