diff --git a/config/mbedtls_config.h b/config/mbedtls_config.h
index 2d01616..0311975 100644
--- a/config/mbedtls_config.h
+++ b/config/mbedtls_config.h
@@ -329,7 +329,9 @@
//#define MBEDTLS_RIPEMD160_ALT
//#define MBEDTLS_RSA_ALT
//#define MBEDTLS_SHA1_ALT
-//#define MBEDTLS_SHA256_ALT
+#ifdef PICO_RP2350
+#define MBEDTLS_SHA256_ALT
+#endif
//#define MBEDTLS_SHA512_ALT
/*
diff --git a/config/rp2350/alt/sha256_alt.c b/config/rp2350/alt/sha256_alt.c
new file mode 100644
index 0000000..66ba8bb
--- /dev/null
+++ b/config/rp2350/alt/sha256_alt.c
@@ -0,0 +1,288 @@
+/*
+ * This file is part of the Pico Keys SDK distribution (https://github.com/polhenarejos/pico-keys-sdk).
+ * Copyright (c) 2022 Pol Henarejos.
+ *
+ * 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, version 3.
+ *
+ * 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, see .
+ */
+
+#include "common.h"
+#include "mbedtls/sha256.h"
+#include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
+#include "pico/sha256.h"
+
+#define SHA256_BLOCK_SIZE 64
+
+static const uint32_t K[] = {
+ 0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5,
+ 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5,
+ 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3,
+ 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174,
+ 0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC,
+ 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
+ 0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7,
+ 0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967,
+ 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13,
+ 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85,
+ 0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3,
+ 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
+ 0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5,
+ 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3,
+ 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208,
+ 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2,
+};
+
+#define SHR(x, n) (((x) & 0xFFFFFFFF) >> (n))
+#define ROTR(x, n) (SHR(x, n) | ((x) << (32 - (n))))
+#define S0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
+#define S1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
+#define S2(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define S3(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define F0(x, y, z) (((x) & (y)) | ((z) & ((x) | (y))))
+#define F1(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
+
+#define R(t) \
+ ( \
+ local.W[t] = S1(local.W[(t) - 2]) + local.W[(t) - 7] + \
+ S0(local.W[(t) - 15]) + local.W[(t) - 16] \
+ )
+
+#define P(a, b, c, d, e, f, g, h, x, K) \
+ do \
+ { \
+ local.temp1 = (h) + S3(e) + F1((e), (f), (g)) + (K) + (x); \
+ local.temp2 = S2(a) + F0((a), (b), (c)); \
+ (d) += local.temp1; (h) = local.temp1 + local.temp2; \
+ } while (0)
+
+
+void mbedtls_sha256_init(mbedtls_sha256_context *ctx) {
+ memset(ctx, 0, sizeof(mbedtls_sha256_context));
+}
+
+void mbedtls_sha256_free(mbedtls_sha256_context *ctx) {
+ if (ctx == NULL) {
+ return;
+ }
+
+ mbedtls_platform_zeroize(ctx, sizeof(mbedtls_sha256_context));
+}
+
+int mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224) {
+ ctx->is224 = is224;
+ if (is224 == 1) {
+ ctx->total[0] = 0;
+ ctx->total[1] = 0;
+
+ ctx->state[0] = 0xC1059ED8;
+ ctx->state[1] = 0x367CD507;
+ ctx->state[2] = 0x3070DD17;
+ ctx->state[3] = 0xF70E5939;
+ ctx->state[4] = 0xFFC00B31;
+ ctx->state[5] = 0x68581511;
+ ctx->state[6] = 0x64F98FA7;
+ ctx->state[7] = 0xBEFA4FA4;
+ }
+ else {
+ return pico_sha256_start_blocking(&ctx->pico_state, SHA256_BIG_ENDIAN, true);
+ }
+ return 0;
+}
+
+static int mbedtls_internal_sha256_process_c(mbedtls_sha256_context *ctx, const unsigned char data[SHA256_BLOCK_SIZE]) {
+ struct {
+ uint32_t temp1, temp2, W[64];
+ uint32_t A[8];
+ } local;
+
+ unsigned int i;
+
+ for (i = 0; i < 8; i++) {
+ local.A[i] = ctx->state[i];
+ }
+
+ for (i = 0; i < 16; i++) {
+ local.W[i] = MBEDTLS_GET_UINT32_BE(data, 4 * i);
+ }
+
+ for (i = 0; i < 16; i += 8) {
+ P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
+ local.A[5], local.A[6], local.A[7], local.W[i+0], K[i+0]);
+ P(local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
+ local.A[4], local.A[5], local.A[6], local.W[i+1], K[i+1]);
+ P(local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
+ local.A[3], local.A[4], local.A[5], local.W[i+2], K[i+2]);
+ P(local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
+ local.A[2], local.A[3], local.A[4], local.W[i+3], K[i+3]);
+ P(local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
+ local.A[1], local.A[2], local.A[3], local.W[i+4], K[i+4]);
+ P(local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
+ local.A[0], local.A[1], local.A[2], local.W[i+5], K[i+5]);
+ P(local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
+ local.A[7], local.A[0], local.A[1], local.W[i+6], K[i+6]);
+ P(local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
+ local.A[6], local.A[7], local.A[0], local.W[i+7], K[i+7]);
+ }
+
+ for (i = 16; i < 64; i += 8) {
+ P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
+ local.A[5], local.A[6], local.A[7], R(i+0), K[i+0]);
+ P(local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
+ local.A[4], local.A[5], local.A[6], R(i+1), K[i+1]);
+ P(local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
+ local.A[3], local.A[4], local.A[5], R(i+2), K[i+2]);
+ P(local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
+ local.A[2], local.A[3], local.A[4], R(i+3), K[i+3]);
+ P(local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
+ local.A[1], local.A[2], local.A[3], R(i+4), K[i+4]);
+ P(local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
+ local.A[0], local.A[1], local.A[2], R(i+5), K[i+5]);
+ P(local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
+ local.A[7], local.A[0], local.A[1], R(i+6), K[i+6]);
+ P(local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
+ local.A[6], local.A[7], local.A[0], R(i+7), K[i+7]);
+ }
+
+ for (i = 0; i < 8; i++) {
+ ctx->state[i] += local.A[i];
+ }
+
+ /* Zeroise buffers and variables to clear sensitive data from memory. */
+ mbedtls_platform_zeroize(&local, sizeof(local));
+
+ return 0;
+}
+
+static size_t mbedtls_internal_sha256_process_many_c(mbedtls_sha256_context *ctx, const uint8_t *data, size_t len) {
+ size_t processed = 0;
+
+ while (len >= SHA256_BLOCK_SIZE) {
+ if (mbedtls_internal_sha256_process_c(ctx, data) != 0) {
+ return 0;
+ }
+
+ data += SHA256_BLOCK_SIZE;
+ len -= SHA256_BLOCK_SIZE;
+
+ processed += SHA256_BLOCK_SIZE;
+ }
+
+ return processed;
+}
+
+int mbedtls_sha256_update(mbedtls_sha256_context *ctx, const unsigned char *input, size_t ilen) {
+
+ if (ctx->is224 == 1) {
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ size_t fill;
+ uint32_t left;
+
+ if (ilen == 0) {
+ return 0;
+ }
+
+ left = ctx->total[0] & 0x3F;
+ fill = SHA256_BLOCK_SIZE - left;
+
+ ctx->total[0] += (uint32_t) ilen;
+ ctx->total[0] &= 0xFFFFFFFF;
+
+ if (ctx->total[0] < (uint32_t) ilen) {
+ ctx->total[1]++;
+ }
+
+ if (left && ilen >= fill) {
+ memcpy((void *) (ctx->buffer + left), input, fill);
+
+ if ((ret = mbedtls_internal_sha256_process_c(ctx, ctx->buffer)) != 0) {
+ return ret;
+ }
+
+ input += fill;
+ ilen -= fill;
+ left = 0;
+ }
+
+ while (ilen >= SHA256_BLOCK_SIZE) {
+ size_t processed = mbedtls_internal_sha256_process_many_c(ctx, input, ilen);
+ if (processed < SHA256_BLOCK_SIZE) {
+ return MBEDTLS_ERR_ERROR_GENERIC_ERROR;
+ }
+
+ input += processed;
+ ilen -= processed;
+ }
+
+ if (ilen > 0) {
+ memcpy((void *) (ctx->buffer + left), input, ilen);
+ }
+ }
+ else {
+ pico_sha256_update_blocking(&ctx->pico_state, (const uint8_t *)input, ilen);
+ }
+ return 0;
+}
+
+int mbedtls_sha256_finish(mbedtls_sha256_context *ctx, unsigned char output[32]) {
+ if (ctx->is224) {
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ uint32_t used;
+ uint32_t high, low;
+
+ used = ctx->total[0] & 0x3F;
+
+ ctx->buffer[used++] = 0x80;
+
+ if (used <= 56) {
+ memset(ctx->buffer + used, 0, 56 - used);
+ } else {
+ memset(ctx->buffer + used, 0, SHA256_BLOCK_SIZE - used);
+
+ if ((ret = mbedtls_internal_sha256_process_c(ctx, ctx->buffer)) != 0) {
+ goto exit;
+ }
+
+ memset(ctx->buffer, 0, 56);
+ }
+
+ high = (ctx->total[0] >> 29) | (ctx->total[1] << 3);
+ low = (ctx->total[0] << 3);
+
+ MBEDTLS_PUT_UINT32_BE(high, ctx->buffer, 56);
+ MBEDTLS_PUT_UINT32_BE(low, ctx->buffer, 60);
+
+ if ((ret = mbedtls_internal_sha256_process_c(ctx, ctx->buffer)) != 0) {
+ goto exit;
+ }
+
+ MBEDTLS_PUT_UINT32_BE(ctx->state[0], output, 0);
+ MBEDTLS_PUT_UINT32_BE(ctx->state[1], output, 4);
+ MBEDTLS_PUT_UINT32_BE(ctx->state[2], output, 8);
+ MBEDTLS_PUT_UINT32_BE(ctx->state[3], output, 12);
+ MBEDTLS_PUT_UINT32_BE(ctx->state[4], output, 16);
+ MBEDTLS_PUT_UINT32_BE(ctx->state[5], output, 20);
+ MBEDTLS_PUT_UINT32_BE(ctx->state[6], output, 24);
+
+ ret = 0;
+
+ exit:
+ mbedtls_sha256_free(ctx);
+ return ret;
+ }
+ else {
+ sha256_result_t result;
+ pico_sha256_finish(&ctx->pico_state, &result);
+ memcpy(output, result.bytes, 32);
+ }
+ return 0;
+}
diff --git a/config/rp2350/alt/sha256_alt.h b/config/rp2350/alt/sha256_alt.h
new file mode 100644
index 0000000..3c47b4f
--- /dev/null
+++ b/config/rp2350/alt/sha256_alt.h
@@ -0,0 +1,36 @@
+/*
+ * This file is part of the Pico Keys SDK distribution (https://github.com/polhenarejos/pico-keys-sdk).
+ * Copyright (c) 2022 Pol Henarejos.
+ *
+ * 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, version 3.
+ *
+ * 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, see .
+ */
+
+#ifndef _SHA256_ALT_H_
+#define _SHA256_ALT_H_
+
+#include "pico_keys.h"
+#include "pico/sha256.h"
+
+typedef struct mbedtls_sha256_context {
+ pico_sha256_state_t MBEDTLS_PRIVATE(pico_state);
+#if defined(MBEDTLS_SHA224_C)
+ unsigned char MBEDTLS_PRIVATE(buffer)[64]; /*!< The data block being processed. */
+ uint32_t MBEDTLS_PRIVATE(total)[2]; /*!< The number of Bytes processed. */
+ uint32_t MBEDTLS_PRIVATE(state)[8]; /*!< The intermediate digest state. */
+ int MBEDTLS_PRIVATE(is224); /*!< Determines which function to use:
+ 0: Use SHA-256, or 1: Use SHA-224. */
+#endif
+}
+mbedtls_sha256_context;
+
+#endif /* _SHA256_ALT_H_ */
diff --git a/pico_keys_sdk_import.cmake b/pico_keys_sdk_import.cmake
index 2e4ce0d..21df5ce 100644
--- a/pico_keys_sdk_import.cmake
+++ b/pico_keys_sdk_import.cmake
@@ -364,6 +364,13 @@ if(PICO_RP2350)
pico_hash_binary(${CMAKE_PROJECT_NAME})
endif()
target_link_libraries(${CMAKE_PROJECT_NAME} PRIVATE pico_bootrom)
+
+ set(INCLUDES ${INCLUDES}
+ ${CMAKE_CURRENT_LIST_DIR}/config/rp2350/alt
+ )
+ set(SOURCES ${SOURCES}
+ ${CMAKE_CURRENT_LIST_DIR}/config/rp2350/alt/sha256_alt.c
+ )
endif()
set(INTERNAL_SOURCES ${SOURCES})
set(SOURCES ${SOURCES} ${EXTERNAL_SOURCES})
@@ -374,7 +381,7 @@ if(NOT TARGET pico_keys_sdk)
pico_add_library(pico_keys_sdk)
pico_add_extra_outputs(${CMAKE_PROJECT_NAME})
- target_link_libraries(${CMAKE_PROJECT_NAME} PRIVATE pico_keys_sdk pico_stdlib pico_multicore pico_rand hardware_flash pico_unique_id pico_aon_timer tinyusb_device tinyusb_board)
+ target_link_libraries(${CMAKE_PROJECT_NAME} PRIVATE pico_keys_sdk pico_stdlib pico_multicore pico_rand hardware_flash pico_unique_id pico_aon_timer pico_sha256 tinyusb_device tinyusb_board)
endif()
target_sources(pico_keys_sdk INTERFACE ${SOURCES})
target_include_directories(pico_keys_sdk INTERFACE ${INCLUDES})