| /* This Source Code Form is subject to the terms of the Mozilla Public |
| * License, v. 2.0. If a copy of the MPL was not distributed with this |
| * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| |
| #ifdef FREEBL_NO_DEPEND |
| #include "stubs.h" |
| #endif |
| #include "blapii.h" |
| #include "blapit.h" |
| #include "gcm.h" |
| #include "ctr.h" |
| #include "secerr.h" |
| #include "prtypes.h" |
| #include "pkcs11t.h" |
| |
| #include <limits.h> |
| |
| /************************************************************************** |
| * First implement the Galois hash function of GCM (gcmHash) * |
| **************************************************************************/ |
| #define GCM_HASH_LEN_LEN 8 /* gcm hash defines lengths to be 64 bits */ |
| |
| typedef struct gcmHashContextStr gcmHashContext; |
| |
| static SECStatus gcmHash_InitContext(gcmHashContext *hash, |
| const unsigned char *H, |
| unsigned int blocksize); |
| static void gcmHash_DestroyContext(gcmHashContext *ghash, PRBool freeit); |
| static SECStatus gcmHash_Update(gcmHashContext *ghash, |
| const unsigned char *buf, unsigned int len, |
| unsigned int blocksize); |
| static SECStatus gcmHash_Sync(gcmHashContext *ghash, unsigned int blocksize); |
| static SECStatus gcmHash_Final(gcmHashContext *gcm, unsigned char *outbuf, |
| unsigned int *outlen, unsigned int maxout, |
| unsigned int blocksize); |
| static SECStatus gcmHash_Reset(gcmHashContext *ghash, |
| const unsigned char *inbuf, |
| unsigned int inbufLen, unsigned int blocksize); |
| |
| /* compile time defines to select how the GF2 multiply is calculated. |
| * There are currently 2 algorithms implemented here: MPI and ALGORITHM_1. |
| * |
| * MPI uses the GF2m implemented in mpi to support GF2 ECC. |
| * ALGORITHM_1 is the Algorithm 1 in both NIST SP 800-38D and |
| * "The Galois/Counter Mode of Operation (GCM)", McGrew & Viega. |
| */ |
| #if !defined(GCM_USE_ALGORITHM_1) && !defined(GCM_USE_MPI) |
| #define GCM_USE_MPI 1 /* MPI is about 5x faster with the |
| * same or less complexity. It's possible to use |
| * tables to speed things up even more */ |
| #endif |
| |
| /* GCM defines the bit string to be LSB first, which is exactly |
| * opposite everyone else, including hardware. build array |
| * to reverse everything. */ |
| static const unsigned char gcm_byte_rev[256] = { |
| 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, |
| 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, |
| 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, |
| 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, |
| 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, |
| 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, |
| 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, |
| 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, |
| 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, |
| 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, |
| 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, |
| 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, |
| 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, |
| 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, |
| 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, |
| 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, |
| 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, |
| 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, |
| 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, |
| 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, |
| 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, |
| 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, |
| 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, |
| 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, |
| 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, |
| 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, |
| 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, |
| 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, |
| 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, |
| 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, |
| 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, |
| 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff |
| }; |
| |
| |
| #ifdef GCM_TRACE |
| #include <stdio.h> |
| |
| #define GCM_TRACE_X(ghash,label) { \ |
| unsigned char _X[MAX_BLOCK_SIZE]; int i; \ |
| gcm_getX(ghash, _X, blocksize); \ |
| printf(label,(ghash)->m); \ |
| for (i=0; i < blocksize; i++) printf("%02x",_X[i]); \ |
| printf("\n"); } |
| #define GCM_TRACE_BLOCK(label,buf,blocksize) {\ |
| printf(label); \ |
| for (i=0; i < blocksize; i++) printf("%02x",buf[i]); \ |
| printf("\n"); } |
| #else |
| #define GCM_TRACE_X(ghash,label) |
| #define GCM_TRACE_BLOCK(label,buf,blocksize) |
| #endif |
| |
| #ifdef GCM_USE_MPI |
| |
| #ifdef GCM_USE_ALGORITHM_1 |
| #error "Only define one of GCM_USE_MPI, GCM_USE_ALGORITHM_1" |
| #endif |
| /* use the MPI functions to calculate Xn = (Xn-1^C_i)*H mod poly */ |
| #include "mpi.h" |
| #include "secmpi.h" |
| #include "mplogic.h" |
| #include "mp_gf2m.h" |
| |
| /* state needed to handle GCM Hash function */ |
| struct gcmHashContextStr { |
| mp_int H; |
| mp_int X; |
| mp_int C_i; |
| const unsigned int *poly; |
| unsigned char buffer[MAX_BLOCK_SIZE]; |
| unsigned int bufLen; |
| int m; /* XXX what is m? */ |
| unsigned char counterBuf[2*GCM_HASH_LEN_LEN]; |
| PRUint64 cLen; |
| }; |
| |
| /* f = x^128 + x^7 + x^2 + x + 1 */ |
| static const unsigned int poly_128[] = { 128, 7, 2, 1, 0 }; |
| |
| /* sigh, GCM defines the bit strings exactly backwards from everything else */ |
| static void |
| gcm_reverse(unsigned char *target, const unsigned char *src, |
| unsigned int blocksize) |
| { |
| unsigned int i; |
| for (i=0; i < blocksize; i++) { |
| target[blocksize-i-1] = gcm_byte_rev[src[i]]; |
| } |
| } |
| |
| /* Initialize a gcmHashContext */ |
| static SECStatus |
| gcmHash_InitContext(gcmHashContext *ghash, const unsigned char *H, |
| unsigned int blocksize) |
| { |
| mp_err err = MP_OKAY; |
| unsigned char H_rev[MAX_BLOCK_SIZE]; |
| |
| MP_DIGITS(&ghash->H) = 0; |
| MP_DIGITS(&ghash->X) = 0; |
| MP_DIGITS(&ghash->C_i) = 0; |
| CHECK_MPI_OK( mp_init(&ghash->H) ); |
| CHECK_MPI_OK( mp_init(&ghash->X) ); |
| CHECK_MPI_OK( mp_init(&ghash->C_i) ); |
| |
| mp_zero(&ghash->X); |
| gcm_reverse(H_rev, H, blocksize); |
| CHECK_MPI_OK( mp_read_unsigned_octets(&ghash->H, H_rev, blocksize) ); |
| |
| /* set the irreducible polynomial. Each blocksize has its own polynomial. |
| * for now only blocksize 16 (=128 bits) is defined */ |
| switch (blocksize) { |
| case 16: /* 128 bits */ |
| ghash->poly = poly_128; |
| break; |
| default: |
| PORT_SetError(SEC_ERROR_INVALID_ARGS); |
| goto cleanup; |
| } |
| ghash->cLen = 0; |
| ghash->bufLen = 0; |
| ghash->m = 0; |
| PORT_Memset(ghash->counterBuf, 0, sizeof(ghash->counterBuf)); |
| return SECSuccess; |
| cleanup: |
| gcmHash_DestroyContext(ghash, PR_FALSE); |
| return SECFailure; |
| } |
| |
| /* Destroy a HashContext (Note we zero the digits so this function |
| * is idempotent if called with freeit == PR_FALSE */ |
| static void |
| gcmHash_DestroyContext(gcmHashContext *ghash, PRBool freeit) |
| { |
| mp_clear(&ghash->H); |
| mp_clear(&ghash->X); |
| mp_clear(&ghash->C_i); |
| MP_DIGITS(&ghash->H) = 0; |
| MP_DIGITS(&ghash->X) = 0; |
| MP_DIGITS(&ghash->C_i) = 0; |
| if (freeit) { |
| PORT_Free(ghash); |
| } |
| } |
| |
| static SECStatus |
| gcm_getX(gcmHashContext *ghash, unsigned char *T, unsigned int blocksize) |
| { |
| int len; |
| mp_err err; |
| unsigned char tmp_buf[MAX_BLOCK_SIZE]; |
| unsigned char *X; |
| |
| len = mp_unsigned_octet_size(&ghash->X); |
| if (len <= 0) { |
| PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); |
| return SECFailure; |
| } |
| X = tmp_buf; |
| PORT_Assert((unsigned int)len <= blocksize); |
| if ((unsigned int)len > blocksize) { |
| PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); |
| return SECFailure; |
| } |
| /* zero pad the result */ |
| if (len != blocksize) { |
| PORT_Memset(X,0,blocksize-len); |
| X += blocksize-len; |
| } |
| |
| err = mp_to_unsigned_octets(&ghash->X, X, len); |
| if (err < 0) { |
| PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); |
| return SECFailure; |
| } |
| gcm_reverse(T, tmp_buf, blocksize); |
| return SECSuccess; |
| } |
| |
| static SECStatus |
| gcm_HashMult(gcmHashContext *ghash, const unsigned char *buf, |
| unsigned int count, unsigned int blocksize) |
| { |
| SECStatus rv = SECFailure; |
| mp_err err = MP_OKAY; |
| unsigned char tmp_buf[MAX_BLOCK_SIZE]; |
| unsigned int i; |
| |
| for (i=0; i < count; i++, buf += blocksize) { |
| ghash->m++; |
| gcm_reverse(tmp_buf, buf, blocksize); |
| CHECK_MPI_OK(mp_read_unsigned_octets(&ghash->C_i, tmp_buf, blocksize)); |
| CHECK_MPI_OK(mp_badd(&ghash->X, &ghash->C_i, &ghash->C_i)); |
| /* |
| * Looking to speed up GCM, this the the place to do it. |
| * There are two areas that can be exploited to speed up this code. |
| * |
| * 1) H is a constant in this multiply. We can precompute H * (0 - 255) |
| * at init time and this becomes an blockize xors of our table lookup. |
| * |
| * 2) poly is a constant for each blocksize. We can calculate the |
| * modulo reduction by a series of adds and shifts. |
| * |
| * For now we are after functionality, so we will go ahead and use |
| * the builtin bmulmod from mpi |
| */ |
| CHECK_MPI_OK(mp_bmulmod(&ghash->C_i, &ghash->H, |
| ghash->poly, &ghash->X)); |
| GCM_TRACE_X(ghash, "X%d = ") |
| } |
| rv = SECSuccess; |
| cleanup: |
| if (rv != SECSuccess) { |
| MP_TO_SEC_ERROR(err); |
| } |
| return rv; |
| } |
| |
| static void |
| gcm_zeroX(gcmHashContext *ghash) |
| { |
| mp_zero(&ghash->X); |
| ghash->m = 0; |
| } |
| |
| #endif |
| |
| #ifdef GCM_USE_ALGORITHM_1 |
| /* use algorithm 1 of McGrew & Viega "The Galois/Counter Mode of Operation" */ |
| |
| #define GCM_ARRAY_SIZE (MAX_BLOCK_SIZE/sizeof(unsigned long)) |
| |
| struct gcmHashContextStr { |
| unsigned long H[GCM_ARRAY_SIZE]; |
| unsigned long X[GCM_ARRAY_SIZE]; |
| unsigned long R; |
| unsigned char buffer[MAX_BLOCK_SIZE]; |
| unsigned int bufLen; |
| int m; |
| unsigned char counterBuf[2*GCM_HASH_LEN_LEN]; |
| PRUint64 cLen; |
| }; |
| |
| static void |
| gcm_bytes_to_longs(unsigned long *l, const unsigned char *c, unsigned int len) |
| { |
| int i,j; |
| int array_size = len/sizeof(unsigned long); |
| |
| PORT_Assert(len % sizeof(unsigned long) == 0); |
| for (i=0; i < array_size; i++) { |
| unsigned long tmp = 0; |
| int byte_offset = i * sizeof(unsigned long); |
| for (j=sizeof(unsigned long)-1; j >= 0; j--) { |
| tmp = (tmp << PR_BITS_PER_BYTE) | gcm_byte_rev[c[byte_offset+j]]; |
| } |
| l[i] = tmp; |
| } |
| } |
| |
| static void |
| gcm_longs_to_bytes(const unsigned long *l, unsigned char *c, unsigned int len) |
| { |
| int i,j; |
| int array_size = len/sizeof(unsigned long); |
| |
| PORT_Assert(len % sizeof(unsigned long) == 0); |
| for (i=0; i < array_size; i++) { |
| unsigned long tmp = l[i]; |
| int byte_offset = i * sizeof(unsigned long); |
| for (j=0; j < sizeof(unsigned long); j++) { |
| c[byte_offset+j] = gcm_byte_rev[tmp & 0xff]; |
| tmp = (tmp >> PR_BITS_PER_BYTE); |
| } |
| } |
| } |
| |
| |
| /* Initialize a gcmHashContext */ |
| static SECStatus |
| gcmHash_InitContext(gcmHashContext *ghash, const unsigned char *H, |
| unsigned int blocksize) |
| { |
| PORT_Memset(ghash->X, 0, sizeof(ghash->X)); |
| PORT_Memset(ghash->H, 0, sizeof(ghash->H)); |
| gcm_bytes_to_longs(ghash->H, H, blocksize); |
| |
| /* set the irreducible polynomial. Each blocksize has its own polynommial |
| * for now only blocksize 16 (=128 bits) is defined */ |
| switch (blocksize) { |
| case 16: /* 128 bits */ |
| ghash->R = (unsigned long) 0x87; /* x^7 + x^2 + x +1 */ |
| break; |
| default: |
| PORT_SetError(SEC_ERROR_INVALID_ARGS); |
| goto cleanup; |
| } |
| ghash->cLen = 0; |
| ghash->bufLen = 0; |
| ghash->m = 0; |
| PORT_Memset(ghash->counterBuf, 0, sizeof(ghash->counterBuf)); |
| return SECSuccess; |
| cleanup: |
| return SECFailure; |
| } |
| |
| /* Destroy a HashContext (Note we zero the digits so this function |
| * is idempotent if called with freeit == PR_FALSE */ |
| static void |
| gcmHash_DestroyContext(gcmHashContext *ghash, PRBool freeit) |
| { |
| if (freeit) { |
| PORT_Free(ghash); |
| } |
| } |
| |
| static unsigned long |
| gcm_shift_one(unsigned long *t, unsigned int count) |
| { |
| unsigned long carry = 0; |
| unsigned long nextcarry = 0; |
| unsigned int i; |
| for (i=0; i < count; i++) { |
| nextcarry = t[i] >> ((sizeof(unsigned long)*PR_BITS_PER_BYTE)-1); |
| t[i] = (t[i] << 1) | carry; |
| carry = nextcarry; |
| } |
| return carry; |
| } |
| |
| static SECStatus |
| gcm_getX(gcmHashContext *ghash, unsigned char *T, unsigned int blocksize) |
| { |
| gcm_longs_to_bytes(ghash->X, T, blocksize); |
| return SECSuccess; |
| } |
| |
| #define GCM_XOR(t, s, len) \ |
| for (l=0; l < len; l++) t[l] ^= s[l] |
| |
| static SECStatus |
| gcm_HashMult(gcmHashContext *ghash, const unsigned char *buf, |
| unsigned int count, unsigned int blocksize) |
| { |
| unsigned long C_i[GCM_ARRAY_SIZE]; |
| unsigned int arraysize = blocksize/sizeof(unsigned long); |
| unsigned int i, j, k, l; |
| |
| for (i=0; i < count; i++, buf += blocksize) { |
| ghash->m++; |
| gcm_bytes_to_longs(C_i, buf, blocksize); |
| GCM_XOR(C_i, ghash->X, arraysize); |
| /* multiply X = C_i * H */ |
| PORT_Memset(ghash->X, 0, sizeof(ghash->X)); |
| for (j=0; j < arraysize; j++) { |
| unsigned long H = ghash->H[j]; |
| for (k=0; k < sizeof(unsigned long)*PR_BITS_PER_BYTE; k++) { |
| if (H & 1) { |
| GCM_XOR(ghash->X, C_i, arraysize); |
| } |
| if (gcm_shift_one(C_i, arraysize)) { |
| C_i[0] = C_i[0] ^ ghash->R; |
| } |
| H = H >> 1; |
| } |
| } |
| GCM_TRACE_X(ghash, "X%d = ") |
| } |
| return SECSuccess; |
| } |
| |
| |
| static void |
| gcm_zeroX(gcmHashContext *ghash) |
| { |
| PORT_Memset(ghash->X, 0, sizeof(ghash->X)); |
| ghash->m = 0; |
| } |
| #endif |
| |
| /* |
| * implement GCM GHASH using the freebl GHASH function. The gcm_HashMult |
| * function always takes blocksize lengths of data. gcmHash_Update will |
| * format the data properly. |
| */ |
| static SECStatus |
| gcmHash_Update(gcmHashContext *ghash, const unsigned char *buf, |
| unsigned int len, unsigned int blocksize) |
| { |
| unsigned int blocks; |
| SECStatus rv; |
| |
| ghash->cLen += (len*PR_BITS_PER_BYTE); |
| |
| /* first deal with the current buffer of data. Try to fill it out so |
| * we can hash it */ |
| if (ghash->bufLen) { |
| unsigned int needed = PR_MIN(len, blocksize - ghash->bufLen); |
| if (needed != 0) { |
| PORT_Memcpy(ghash->buffer+ghash->bufLen, buf, needed); |
| } |
| buf += needed; |
| len -= needed; |
| ghash->bufLen += needed; |
| if (len == 0) { |
| /* didn't add enough to hash the data, nothing more do do */ |
| return SECSuccess; |
| } |
| PORT_Assert(ghash->bufLen == blocksize); |
| /* hash the buffer and clear it */ |
| rv = gcm_HashMult(ghash, ghash->buffer, 1, blocksize); |
| PORT_Memset(ghash->buffer, 0, blocksize); |
| ghash->bufLen = 0; |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| } |
| /* now hash any full blocks remaining in the data stream */ |
| blocks = len/blocksize; |
| if (blocks) { |
| rv = gcm_HashMult(ghash, buf, blocks, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| buf += blocks*blocksize; |
| len -= blocks*blocksize; |
| } |
| |
| /* save any remainder in the buffer to be hashed with the next call */ |
| if (len != 0) { |
| PORT_Memcpy(ghash->buffer, buf, len); |
| ghash->bufLen = len; |
| } |
| return SECSuccess; |
| } |
| |
| /* |
| * write out any partial blocks zero padded through the GHASH engine, |
| * save the lengths for the final completion of the hash |
| */ |
| static SECStatus |
| gcmHash_Sync(gcmHashContext *ghash, unsigned int blocksize) |
| { |
| int i; |
| SECStatus rv; |
| |
| /* copy the previous counter to the upper block */ |
| PORT_Memcpy(ghash->counterBuf, &ghash->counterBuf[GCM_HASH_LEN_LEN], |
| GCM_HASH_LEN_LEN); |
| /* copy the current counter in the lower block */ |
| for (i=0; i < GCM_HASH_LEN_LEN; i++) { |
| ghash->counterBuf[GCM_HASH_LEN_LEN+i] = |
| (ghash->cLen >> ((GCM_HASH_LEN_LEN-1-i)*PR_BITS_PER_BYTE)) & 0xff; |
| } |
| ghash->cLen = 0; |
| |
| /* now zero fill the buffer and hash the last block */ |
| if (ghash->bufLen) { |
| PORT_Memset(ghash->buffer+ghash->bufLen, 0, blocksize - ghash->bufLen); |
| rv = gcm_HashMult(ghash, ghash->buffer, 1, blocksize); |
| PORT_Memset(ghash->buffer, 0, blocksize); |
| ghash->bufLen = 0; |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| } |
| return SECSuccess; |
| } |
| |
| /* |
| * This does the final sync, hashes the lengths, then returns |
| * "T", the hashed output. |
| */ |
| static SECStatus |
| gcmHash_Final(gcmHashContext *ghash, unsigned char *outbuf, |
| unsigned int *outlen, unsigned int maxout, |
| unsigned int blocksize) |
| { |
| unsigned char T[MAX_BLOCK_SIZE]; |
| SECStatus rv; |
| |
| rv = gcmHash_Sync(ghash, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| |
| rv = gcm_HashMult(ghash, ghash->counterBuf, (GCM_HASH_LEN_LEN*2)/blocksize, |
| blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| |
| GCM_TRACE_X(ghash, "GHASH(H,A,C) = ") |
| |
| rv = gcm_getX(ghash, T, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| |
| if (maxout > blocksize) maxout = blocksize; |
| PORT_Memcpy(outbuf, T, maxout); |
| *outlen = maxout; |
| return SECSuccess; |
| } |
| |
| SECStatus |
| gcmHash_Reset(gcmHashContext *ghash, const unsigned char *AAD, |
| unsigned int AADLen, unsigned int blocksize) |
| { |
| SECStatus rv; |
| |
| ghash->cLen = 0; |
| PORT_Memset(ghash->counterBuf, 0, GCM_HASH_LEN_LEN*2); |
| ghash->bufLen = 0; |
| gcm_zeroX(ghash); |
| |
| /* now kick things off by hashing the Additional Authenticated Data */ |
| if (AADLen != 0) { |
| rv = gcmHash_Update(ghash, AAD, AADLen, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| rv = gcmHash_Sync(ghash, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| } |
| return SECSuccess; |
| } |
| |
| /************************************************************************** |
| * Now implement the GCM using gcmHash and CTR * |
| **************************************************************************/ |
| |
| /* state to handle the full GCM operation (hash and counter) */ |
| struct GCMContextStr { |
| gcmHashContext ghash_context; |
| CTRContext ctr_context; |
| unsigned long tagBits; |
| unsigned char tagKey[MAX_BLOCK_SIZE]; |
| }; |
| |
| GCMContext * |
| GCM_CreateContext(void *context, freeblCipherFunc cipher, |
| const unsigned char *params, unsigned int blocksize) |
| { |
| GCMContext *gcm = NULL; |
| gcmHashContext *ghash; |
| unsigned char H[MAX_BLOCK_SIZE]; |
| unsigned int tmp; |
| PRBool freeCtr = PR_FALSE; |
| PRBool freeHash = PR_FALSE; |
| const CK_GCM_PARAMS *gcmParams = (const CK_GCM_PARAMS *)params; |
| CK_AES_CTR_PARAMS ctrParams; |
| SECStatus rv; |
| |
| if (blocksize > MAX_BLOCK_SIZE || blocksize > sizeof(ctrParams.cb)) { |
| PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); |
| return NULL; |
| } |
| gcm = PORT_ZNew(GCMContext); |
| if (gcm == NULL) { |
| return NULL; |
| } |
| /* first fill in the ghash context */ |
| ghash = &gcm->ghash_context; |
| PORT_Memset(H, 0, blocksize); |
| rv = (*cipher)(context, H, &tmp, blocksize, H, blocksize, blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| rv = gcmHash_InitContext(ghash, H, blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| freeHash = PR_TRUE; |
| |
| /* fill in the Counter context */ |
| ctrParams.ulCounterBits = 32; |
| PORT_Memset(ctrParams.cb, 0, sizeof(ctrParams.cb)); |
| if ((blocksize == 16) && (gcmParams->ulIvLen == 12)) { |
| PORT_Memcpy(ctrParams.cb, gcmParams->pIv, gcmParams->ulIvLen); |
| ctrParams.cb[blocksize-1] = 1; |
| } else { |
| rv = gcmHash_Update(ghash, gcmParams->pIv, gcmParams->ulIvLen, |
| blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| rv = gcmHash_Final(ghash, ctrParams.cb, &tmp, blocksize, blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| } |
| rv = CTR_InitContext(&gcm->ctr_context, context, cipher, |
| (unsigned char *)&ctrParams, blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| freeCtr = PR_TRUE; |
| |
| /* fill in the gcm structure */ |
| gcm->tagBits = gcmParams->ulTagBits; /* save for final step */ |
| /* calculate the final tag key. NOTE: gcm->tagKey is zero to start with. |
| * if this assumption changes, we would need to explicitly clear it here */ |
| rv = CTR_Update(&gcm->ctr_context, gcm->tagKey, &tmp, blocksize, |
| gcm->tagKey, blocksize, blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| |
| /* finally mix in the AAD data */ |
| rv = gcmHash_Reset(ghash, gcmParams->pAAD, gcmParams->ulAADLen, blocksize); |
| if (rv != SECSuccess) { |
| goto loser; |
| } |
| |
| return gcm; |
| |
| loser: |
| if (freeCtr) { |
| CTR_DestroyContext(&gcm->ctr_context, PR_FALSE); |
| } |
| if (freeHash) { |
| gcmHash_DestroyContext(&gcm->ghash_context, PR_FALSE); |
| } |
| if (gcm) { |
| PORT_Free(gcm); |
| } |
| return NULL; |
| } |
| |
| void |
| GCM_DestroyContext(GCMContext *gcm, PRBool freeit) |
| { |
| /* these two are statically allocated and will be freed when we free |
| * gcm. call their destroy functions to free up any locally |
| * allocated data (like mp_int's) */ |
| CTR_DestroyContext(&gcm->ctr_context, PR_FALSE); |
| gcmHash_DestroyContext(&gcm->ghash_context, PR_FALSE); |
| if (freeit) { |
| PORT_Free(gcm); |
| } |
| } |
| |
| static SECStatus |
| gcm_GetTag(GCMContext *gcm, unsigned char *outbuf, |
| unsigned int *outlen, unsigned int maxout, |
| unsigned int blocksize) |
| { |
| unsigned int tagBytes; |
| unsigned int extra; |
| unsigned int i; |
| SECStatus rv; |
| |
| tagBytes = (gcm->tagBits + (PR_BITS_PER_BYTE-1)) / PR_BITS_PER_BYTE; |
| extra = tagBytes*PR_BITS_PER_BYTE - gcm->tagBits; |
| |
| if (outbuf == NULL) { |
| *outlen = tagBytes; |
| PORT_SetError(SEC_ERROR_OUTPUT_LEN); |
| return SECFailure; |
| } |
| |
| if (maxout < tagBytes) { |
| *outlen = tagBytes; |
| PORT_SetError(SEC_ERROR_OUTPUT_LEN); |
| return SECFailure; |
| } |
| maxout = tagBytes; |
| rv = gcmHash_Final(&gcm->ghash_context, outbuf, outlen, maxout, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| |
| GCM_TRACE_BLOCK("GHASH=", outbuf, blocksize); |
| GCM_TRACE_BLOCK("Y0=", gcm->tagKey, blocksize); |
| for (i=0; i < *outlen; i++) { |
| outbuf[i] ^= gcm->tagKey[i]; |
| } |
| GCM_TRACE_BLOCK("Y0=", gcm->tagKey, blocksize); |
| GCM_TRACE_BLOCK("T=", outbuf, blocksize); |
| /* mask off any extra bits we got */ |
| if (extra) { |
| outbuf[tagBytes-1] &= ~((1 << extra)-1); |
| } |
| return SECSuccess; |
| } |
| |
| |
| /* |
| * See The Galois/Counter Mode of Operation, McGrew and Viega. |
| * GCM is basically counter mode with a specific initialization and |
| * built in macing operation. |
| */ |
| SECStatus |
| GCM_EncryptUpdate(GCMContext *gcm, unsigned char *outbuf, |
| unsigned int *outlen, unsigned int maxout, |
| const unsigned char *inbuf, unsigned int inlen, |
| unsigned int blocksize) |
| { |
| SECStatus rv; |
| unsigned int tagBytes; |
| unsigned int len; |
| |
| tagBytes = (gcm->tagBits + (PR_BITS_PER_BYTE-1)) / PR_BITS_PER_BYTE; |
| if (UINT_MAX - inlen < tagBytes) { |
| PORT_SetError(SEC_ERROR_INPUT_LEN); |
| return SECFailure; |
| } |
| if (maxout < inlen + tagBytes) { |
| *outlen = inlen + tagBytes; |
| PORT_SetError(SEC_ERROR_OUTPUT_LEN); |
| return SECFailure; |
| } |
| |
| rv = CTR_Update(&gcm->ctr_context, outbuf, outlen, maxout, |
| inbuf, inlen, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| rv = gcmHash_Update(&gcm->ghash_context, outbuf, *outlen, blocksize); |
| if (rv != SECSuccess) { |
| PORT_Memset(outbuf, 0, *outlen); /* clear the output buffer */ |
| *outlen = 0; |
| return SECFailure; |
| } |
| rv = gcm_GetTag(gcm, outbuf + *outlen, &len, maxout - *outlen, blocksize); |
| if (rv != SECSuccess) { |
| PORT_Memset(outbuf, 0, *outlen); /* clear the output buffer */ |
| *outlen = 0; |
| return SECFailure; |
| }; |
| *outlen += len; |
| return SECSuccess; |
| } |
| |
| /* |
| * See The Galois/Counter Mode of Operation, McGrew and Viega. |
| * GCM is basically counter mode with a specific initialization and |
| * built in macing operation. NOTE: the only difference between Encrypt |
| * and Decrypt is when we calculate the mac. That is because the mac must |
| * always be calculated on the cipher text, not the plain text, so for |
| * encrypt, we do the CTR update first and for decrypt we do the mac first. |
| */ |
| SECStatus |
| GCM_DecryptUpdate(GCMContext *gcm, unsigned char *outbuf, |
| unsigned int *outlen, unsigned int maxout, |
| const unsigned char *inbuf, unsigned int inlen, |
| unsigned int blocksize) |
| { |
| SECStatus rv; |
| unsigned int tagBytes; |
| unsigned char tag[MAX_BLOCK_SIZE]; |
| const unsigned char *intag; |
| unsigned int len; |
| |
| tagBytes = (gcm->tagBits + (PR_BITS_PER_BYTE-1)) / PR_BITS_PER_BYTE; |
| |
| /* get the authentication block */ |
| if (inlen < tagBytes) { |
| PORT_SetError(SEC_ERROR_INPUT_LEN); |
| return SECFailure; |
| } |
| |
| inlen -= tagBytes; |
| intag = inbuf + inlen; |
| |
| /* verify the block */ |
| rv = gcmHash_Update(&gcm->ghash_context, inbuf, inlen, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| rv = gcm_GetTag(gcm, tag, &len, blocksize, blocksize); |
| if (rv != SECSuccess) { |
| return SECFailure; |
| } |
| /* Don't decrypt if we can't authenticate the encrypted data! |
| * This assumes that if tagBits is not a multiple of 8, intag will |
| * preserve the masked off missing bits. */ |
| if (NSS_SecureMemcmp(tag, intag, tagBytes) != 0) { |
| /* force a CKR_ENCRYPTED_DATA_INVALID error at in softoken */ |
| PORT_SetError(SEC_ERROR_BAD_DATA); |
| return SECFailure; |
| } |
| /* finish the decryption */ |
| return CTR_Update(&gcm->ctr_context, outbuf, outlen, maxout, |
| inbuf, inlen, blocksize); |
| } |