| /** |
| * \file poly1305.c |
| * |
| * \brief Poly1305 authentication algorithm. |
| * |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #include "common.h" |
| |
| #if defined(MBEDTLS_POLY1305_C) |
| |
| #include "mbedtls/poly1305.h" |
| #include "mbedtls/platform_util.h" |
| #include "mbedtls/error.h" |
| |
| #include <string.h> |
| |
| #include "mbedtls/platform.h" |
| |
| #if !defined(MBEDTLS_POLY1305_ALT) |
| |
| #define POLY1305_BLOCK_SIZE_BYTES (16U) |
| |
| /* |
| * Our implementation is tuned for 32-bit platforms with a 64-bit multiplier. |
| * However we provided an alternative for platforms without such a multiplier. |
| */ |
| #if defined(MBEDTLS_NO_64BIT_MULTIPLICATION) |
| static uint64_t mul64(uint32_t a, uint32_t b) |
| { |
| /* a = al + 2**16 ah, b = bl + 2**16 bh */ |
| const uint16_t al = (uint16_t) a; |
| const uint16_t bl = (uint16_t) b; |
| const uint16_t ah = a >> 16; |
| const uint16_t bh = b >> 16; |
| |
| /* ab = al*bl + 2**16 (ah*bl + bl*bh) + 2**32 ah*bh */ |
| const uint32_t lo = (uint32_t) al * bl; |
| const uint64_t me = (uint64_t) ((uint32_t) ah * bl) + (uint32_t) al * bh; |
| const uint32_t hi = (uint32_t) ah * bh; |
| |
| return lo + (me << 16) + ((uint64_t) hi << 32); |
| } |
| #else |
| static inline uint64_t mul64(uint32_t a, uint32_t b) |
| { |
| return (uint64_t) a * b; |
| } |
| #endif |
| |
| |
| /** |
| * \brief Process blocks with Poly1305. |
| * |
| * \param ctx The Poly1305 context. |
| * \param nblocks Number of blocks to process. Note that this |
| * function only processes full blocks. |
| * \param input Buffer containing the input block(s). |
| * \param needs_padding Set to 0 if the padding bit has already been |
| * applied to the input data before calling this |
| * function. Otherwise, set this parameter to 1. |
| */ |
| static void poly1305_process(mbedtls_poly1305_context *ctx, |
| size_t nblocks, |
| const unsigned char *input, |
| uint32_t needs_padding) |
| { |
| uint64_t d0, d1, d2, d3; |
| uint32_t acc0, acc1, acc2, acc3, acc4; |
| uint32_t r0, r1, r2, r3; |
| uint32_t rs1, rs2, rs3; |
| size_t offset = 0U; |
| size_t i; |
| |
| r0 = ctx->r[0]; |
| r1 = ctx->r[1]; |
| r2 = ctx->r[2]; |
| r3 = ctx->r[3]; |
| |
| rs1 = r1 + (r1 >> 2U); |
| rs2 = r2 + (r2 >> 2U); |
| rs3 = r3 + (r3 >> 2U); |
| |
| acc0 = ctx->acc[0]; |
| acc1 = ctx->acc[1]; |
| acc2 = ctx->acc[2]; |
| acc3 = ctx->acc[3]; |
| acc4 = ctx->acc[4]; |
| |
| /* Process full blocks */ |
| for (i = 0U; i < nblocks; i++) { |
| /* The input block is treated as a 128-bit little-endian integer */ |
| d0 = MBEDTLS_GET_UINT32_LE(input, offset + 0); |
| d1 = MBEDTLS_GET_UINT32_LE(input, offset + 4); |
| d2 = MBEDTLS_GET_UINT32_LE(input, offset + 8); |
| d3 = MBEDTLS_GET_UINT32_LE(input, offset + 12); |
| |
| /* Compute: acc += (padded) block as a 130-bit integer */ |
| d0 += (uint64_t) acc0; |
| d1 += (uint64_t) acc1 + (d0 >> 32U); |
| d2 += (uint64_t) acc2 + (d1 >> 32U); |
| d3 += (uint64_t) acc3 + (d2 >> 32U); |
| acc0 = (uint32_t) d0; |
| acc1 = (uint32_t) d1; |
| acc2 = (uint32_t) d2; |
| acc3 = (uint32_t) d3; |
| acc4 += (uint32_t) (d3 >> 32U) + needs_padding; |
| |
| /* Compute: acc *= r */ |
| d0 = mul64(acc0, r0) + |
| mul64(acc1, rs3) + |
| mul64(acc2, rs2) + |
| mul64(acc3, rs1); |
| d1 = mul64(acc0, r1) + |
| mul64(acc1, r0) + |
| mul64(acc2, rs3) + |
| mul64(acc3, rs2) + |
| mul64(acc4, rs1); |
| d2 = mul64(acc0, r2) + |
| mul64(acc1, r1) + |
| mul64(acc2, r0) + |
| mul64(acc3, rs3) + |
| mul64(acc4, rs2); |
| d3 = mul64(acc0, r3) + |
| mul64(acc1, r2) + |
| mul64(acc2, r1) + |
| mul64(acc3, r0) + |
| mul64(acc4, rs3); |
| acc4 *= r0; |
| |
| /* Compute: acc %= (2^130 - 5) (partial remainder) */ |
| d1 += (d0 >> 32); |
| d2 += (d1 >> 32); |
| d3 += (d2 >> 32); |
| acc0 = (uint32_t) d0; |
| acc1 = (uint32_t) d1; |
| acc2 = (uint32_t) d2; |
| acc3 = (uint32_t) d3; |
| acc4 = (uint32_t) (d3 >> 32) + acc4; |
| |
| d0 = (uint64_t) acc0 + (acc4 >> 2) + (acc4 & 0xFFFFFFFCU); |
| acc4 &= 3U; |
| acc0 = (uint32_t) d0; |
| d0 = (uint64_t) acc1 + (d0 >> 32U); |
| acc1 = (uint32_t) d0; |
| d0 = (uint64_t) acc2 + (d0 >> 32U); |
| acc2 = (uint32_t) d0; |
| d0 = (uint64_t) acc3 + (d0 >> 32U); |
| acc3 = (uint32_t) d0; |
| d0 = (uint64_t) acc4 + (d0 >> 32U); |
| acc4 = (uint32_t) d0; |
| |
| offset += POLY1305_BLOCK_SIZE_BYTES; |
| } |
| |
| ctx->acc[0] = acc0; |
| ctx->acc[1] = acc1; |
| ctx->acc[2] = acc2; |
| ctx->acc[3] = acc3; |
| ctx->acc[4] = acc4; |
| } |
| |
| /** |
| * \brief Compute the Poly1305 MAC |
| * |
| * \param ctx The Poly1305 context. |
| * \param mac The buffer to where the MAC is written. Must be |
| * big enough to contain the 16-byte MAC. |
| */ |
| static void poly1305_compute_mac(const mbedtls_poly1305_context *ctx, |
| unsigned char mac[16]) |
| { |
| uint64_t d; |
| uint32_t g0, g1, g2, g3, g4; |
| uint32_t acc0, acc1, acc2, acc3, acc4; |
| uint32_t mask; |
| uint32_t mask_inv; |
| |
| acc0 = ctx->acc[0]; |
| acc1 = ctx->acc[1]; |
| acc2 = ctx->acc[2]; |
| acc3 = ctx->acc[3]; |
| acc4 = ctx->acc[4]; |
| |
| /* Before adding 's' we ensure that the accumulator is mod 2^130 - 5. |
| * We do this by calculating acc - (2^130 - 5), then checking if |
| * the 131st bit is set. If it is, then reduce: acc -= (2^130 - 5) |
| */ |
| |
| /* Calculate acc + -(2^130 - 5) */ |
| d = ((uint64_t) acc0 + 5U); |
| g0 = (uint32_t) d; |
| d = ((uint64_t) acc1 + (d >> 32)); |
| g1 = (uint32_t) d; |
| d = ((uint64_t) acc2 + (d >> 32)); |
| g2 = (uint32_t) d; |
| d = ((uint64_t) acc3 + (d >> 32)); |
| g3 = (uint32_t) d; |
| g4 = acc4 + (uint32_t) (d >> 32U); |
| |
| /* mask == 0xFFFFFFFF if 131st bit is set, otherwise mask == 0 */ |
| mask = (uint32_t) 0U - (g4 >> 2U); |
| mask_inv = ~mask; |
| |
| /* If 131st bit is set then acc=g, otherwise, acc is unmodified */ |
| acc0 = (acc0 & mask_inv) | (g0 & mask); |
| acc1 = (acc1 & mask_inv) | (g1 & mask); |
| acc2 = (acc2 & mask_inv) | (g2 & mask); |
| acc3 = (acc3 & mask_inv) | (g3 & mask); |
| |
| /* Add 's' */ |
| d = (uint64_t) acc0 + ctx->s[0]; |
| acc0 = (uint32_t) d; |
| d = (uint64_t) acc1 + ctx->s[1] + (d >> 32U); |
| acc1 = (uint32_t) d; |
| d = (uint64_t) acc2 + ctx->s[2] + (d >> 32U); |
| acc2 = (uint32_t) d; |
| acc3 += ctx->s[3] + (uint32_t) (d >> 32U); |
| |
| /* Compute MAC (128 least significant bits of the accumulator) */ |
| MBEDTLS_PUT_UINT32_LE(acc0, mac, 0); |
| MBEDTLS_PUT_UINT32_LE(acc1, mac, 4); |
| MBEDTLS_PUT_UINT32_LE(acc2, mac, 8); |
| MBEDTLS_PUT_UINT32_LE(acc3, mac, 12); |
| } |
| |
| void mbedtls_poly1305_init(mbedtls_poly1305_context *ctx) |
| { |
| mbedtls_platform_zeroize(ctx, sizeof(mbedtls_poly1305_context)); |
| } |
| |
| void mbedtls_poly1305_free(mbedtls_poly1305_context *ctx) |
| { |
| if (ctx == NULL) { |
| return; |
| } |
| |
| mbedtls_platform_zeroize(ctx, sizeof(mbedtls_poly1305_context)); |
| } |
| |
| int mbedtls_poly1305_starts(mbedtls_poly1305_context *ctx, |
| const unsigned char key[32]) |
| { |
| /* r &= 0x0ffffffc0ffffffc0ffffffc0fffffff */ |
| ctx->r[0] = MBEDTLS_GET_UINT32_LE(key, 0) & 0x0FFFFFFFU; |
| ctx->r[1] = MBEDTLS_GET_UINT32_LE(key, 4) & 0x0FFFFFFCU; |
| ctx->r[2] = MBEDTLS_GET_UINT32_LE(key, 8) & 0x0FFFFFFCU; |
| ctx->r[3] = MBEDTLS_GET_UINT32_LE(key, 12) & 0x0FFFFFFCU; |
| |
| ctx->s[0] = MBEDTLS_GET_UINT32_LE(key, 16); |
| ctx->s[1] = MBEDTLS_GET_UINT32_LE(key, 20); |
| ctx->s[2] = MBEDTLS_GET_UINT32_LE(key, 24); |
| ctx->s[3] = MBEDTLS_GET_UINT32_LE(key, 28); |
| |
| /* Initial accumulator state */ |
| ctx->acc[0] = 0U; |
| ctx->acc[1] = 0U; |
| ctx->acc[2] = 0U; |
| ctx->acc[3] = 0U; |
| ctx->acc[4] = 0U; |
| |
| /* Queue initially empty */ |
| mbedtls_platform_zeroize(ctx->queue, sizeof(ctx->queue)); |
| ctx->queue_len = 0U; |
| |
| return 0; |
| } |
| |
| int mbedtls_poly1305_update(mbedtls_poly1305_context *ctx, |
| const unsigned char *input, |
| size_t ilen) |
| { |
| size_t offset = 0U; |
| size_t remaining = ilen; |
| size_t queue_free_len; |
| size_t nblocks; |
| |
| if ((remaining > 0U) && (ctx->queue_len > 0U)) { |
| queue_free_len = (POLY1305_BLOCK_SIZE_BYTES - ctx->queue_len); |
| |
| if (ilen < queue_free_len) { |
| /* Not enough data to complete the block. |
| * Store this data with the other leftovers. |
| */ |
| memcpy(&ctx->queue[ctx->queue_len], |
| input, |
| ilen); |
| |
| ctx->queue_len += ilen; |
| |
| remaining = 0U; |
| } else { |
| /* Enough data to produce a complete block */ |
| memcpy(&ctx->queue[ctx->queue_len], |
| input, |
| queue_free_len); |
| |
| ctx->queue_len = 0U; |
| |
| poly1305_process(ctx, 1U, ctx->queue, 1U); /* add padding bit */ |
| |
| offset += queue_free_len; |
| remaining -= queue_free_len; |
| } |
| } |
| |
| if (remaining >= POLY1305_BLOCK_SIZE_BYTES) { |
| nblocks = remaining / POLY1305_BLOCK_SIZE_BYTES; |
| |
| poly1305_process(ctx, nblocks, &input[offset], 1U); |
| |
| offset += nblocks * POLY1305_BLOCK_SIZE_BYTES; |
| remaining %= POLY1305_BLOCK_SIZE_BYTES; |
| } |
| |
| if (remaining > 0U) { |
| /* Store partial block */ |
| ctx->queue_len = remaining; |
| memcpy(ctx->queue, &input[offset], remaining); |
| } |
| |
| return 0; |
| } |
| |
| int mbedtls_poly1305_finish(mbedtls_poly1305_context *ctx, |
| unsigned char mac[16]) |
| { |
| /* Process any leftover data */ |
| if (ctx->queue_len > 0U) { |
| /* Add padding bit */ |
| ctx->queue[ctx->queue_len] = 1U; |
| ctx->queue_len++; |
| |
| /* Pad with zeroes */ |
| memset(&ctx->queue[ctx->queue_len], |
| 0, |
| POLY1305_BLOCK_SIZE_BYTES - ctx->queue_len); |
| |
| poly1305_process(ctx, 1U, /* Process 1 block */ |
| ctx->queue, 0U); /* Already padded above */ |
| } |
| |
| poly1305_compute_mac(ctx, mac); |
| |
| return 0; |
| } |
| |
| int mbedtls_poly1305_mac(const unsigned char key[32], |
| const unsigned char *input, |
| size_t ilen, |
| unsigned char mac[16]) |
| { |
| mbedtls_poly1305_context ctx; |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| mbedtls_poly1305_init(&ctx); |
| |
| ret = mbedtls_poly1305_starts(&ctx, key); |
| if (ret != 0) { |
| goto cleanup; |
| } |
| |
| ret = mbedtls_poly1305_update(&ctx, input, ilen); |
| if (ret != 0) { |
| goto cleanup; |
| } |
| |
| ret = mbedtls_poly1305_finish(&ctx, mac); |
| |
| cleanup: |
| mbedtls_poly1305_free(&ctx); |
| return ret; |
| } |
| |
| #endif /* MBEDTLS_POLY1305_ALT */ |
| |
| #if defined(MBEDTLS_SELF_TEST) |
| |
| static const unsigned char test_keys[2][32] = |
| { |
| { |
| 0x85, 0xd6, 0xbe, 0x78, 0x57, 0x55, 0x6d, 0x33, |
| 0x7f, 0x44, 0x52, 0xfe, 0x42, 0xd5, 0x06, 0xa8, |
| 0x01, 0x03, 0x80, 0x8a, 0xfb, 0x0d, 0xb2, 0xfd, |
| 0x4a, 0xbf, 0xf6, 0xaf, 0x41, 0x49, 0xf5, 0x1b |
| }, |
| { |
| 0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, |
| 0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0, |
| 0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, |
| 0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0 |
| } |
| }; |
| |
| static const unsigned char test_data[2][127] = |
| { |
| { |
| 0x43, 0x72, 0x79, 0x70, 0x74, 0x6f, 0x67, 0x72, |
| 0x61, 0x70, 0x68, 0x69, 0x63, 0x20, 0x46, 0x6f, |
| 0x72, 0x75, 0x6d, 0x20, 0x52, 0x65, 0x73, 0x65, |
| 0x61, 0x72, 0x63, 0x68, 0x20, 0x47, 0x72, 0x6f, |
| 0x75, 0x70 |
| }, |
| { |
| 0x27, 0x54, 0x77, 0x61, 0x73, 0x20, 0x62, 0x72, |
| 0x69, 0x6c, 0x6c, 0x69, 0x67, 0x2c, 0x20, 0x61, |
| 0x6e, 0x64, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, |
| 0x6c, 0x69, 0x74, 0x68, 0x79, 0x20, 0x74, 0x6f, |
| 0x76, 0x65, 0x73, 0x0a, 0x44, 0x69, 0x64, 0x20, |
| 0x67, 0x79, 0x72, 0x65, 0x20, 0x61, 0x6e, 0x64, |
| 0x20, 0x67, 0x69, 0x6d, 0x62, 0x6c, 0x65, 0x20, |
| 0x69, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x77, |
| 0x61, 0x62, 0x65, 0x3a, 0x0a, 0x41, 0x6c, 0x6c, |
| 0x20, 0x6d, 0x69, 0x6d, 0x73, 0x79, 0x20, 0x77, |
| 0x65, 0x72, 0x65, 0x20, 0x74, 0x68, 0x65, 0x20, |
| 0x62, 0x6f, 0x72, 0x6f, 0x67, 0x6f, 0x76, 0x65, |
| 0x73, 0x2c, 0x0a, 0x41, 0x6e, 0x64, 0x20, 0x74, |
| 0x68, 0x65, 0x20, 0x6d, 0x6f, 0x6d, 0x65, 0x20, |
| 0x72, 0x61, 0x74, 0x68, 0x73, 0x20, 0x6f, 0x75, |
| 0x74, 0x67, 0x72, 0x61, 0x62, 0x65, 0x2e |
| } |
| }; |
| |
| static const size_t test_data_len[2] = |
| { |
| 34U, |
| 127U |
| }; |
| |
| static const unsigned char test_mac[2][16] = |
| { |
| { |
| 0xa8, 0x06, 0x1d, 0xc1, 0x30, 0x51, 0x36, 0xc6, |
| 0xc2, 0x2b, 0x8b, 0xaf, 0x0c, 0x01, 0x27, 0xa9 |
| }, |
| { |
| 0x45, 0x41, 0x66, 0x9a, 0x7e, 0xaa, 0xee, 0x61, |
| 0xe7, 0x08, 0xdc, 0x7c, 0xbc, 0xc5, 0xeb, 0x62 |
| } |
| }; |
| |
| /* Make sure no other definition is already present. */ |
| #undef ASSERT |
| |
| #define ASSERT(cond, args) \ |
| do \ |
| { \ |
| if (!(cond)) \ |
| { \ |
| if (verbose != 0) \ |
| mbedtls_printf args; \ |
| \ |
| return -1; \ |
| } \ |
| } \ |
| while (0) |
| |
| int mbedtls_poly1305_self_test(int verbose) |
| { |
| unsigned char mac[16]; |
| unsigned i; |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| for (i = 0U; i < 2U; i++) { |
| if (verbose != 0) { |
| mbedtls_printf(" Poly1305 test %u ", i); |
| } |
| |
| ret = mbedtls_poly1305_mac(test_keys[i], |
| test_data[i], |
| test_data_len[i], |
| mac); |
| ASSERT(0 == ret, ("error code: %i\n", ret)); |
| |
| ASSERT(0 == memcmp(mac, test_mac[i], 16U), ("failed (mac)\n")); |
| |
| if (verbose != 0) { |
| mbedtls_printf("passed\n"); |
| } |
| } |
| |
| if (verbose != 0) { |
| mbedtls_printf("\n"); |
| } |
| |
| return 0; |
| } |
| |
| #endif /* MBEDTLS_SELF_TEST */ |
| |
| #endif /* MBEDTLS_POLY1305_C */ |
