diff --git a/library/psa_crypto_hash.c b/library/psa_crypto_hash.c
new file mode 100644
index 0000000..deb13c2
--- /dev/null
+++ b/library/psa_crypto_hash.c
@@ -0,0 +1,442 @@
+/*
+ *  PSA hashing layer on top of Mbed TLS software crypto
+ */
+/*
+ *  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_PSA_CRYPTO_C)
+
+#include <psa/crypto.h>
+#include "psa_crypto_core.h"
+#include "psa_crypto_hash.h"
+
+#include <mbedtls/error.h>
+#include <string.h>
+
+psa_status_t mbedtls_psa_hash_compute(
+    psa_algorithm_t alg,
+    const uint8_t *input,
+    size_t input_length,
+    uint8_t *hash,
+    size_t hash_size,
+    size_t *hash_length)
+{
+    mbedtls_psa_hash_operation_t operation = MBEDTLS_PSA_HASH_OPERATION_INIT;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    *hash_length = hash_size;
+    status = mbedtls_psa_hash_setup( &operation, alg );
+    if( status != PSA_SUCCESS )
+        goto exit;
+    status = mbedtls_psa_hash_update( &operation, input, input_length );
+    if( status != PSA_SUCCESS )
+        goto exit;
+    status = mbedtls_psa_hash_finish( &operation, hash, hash_size, hash_length );
+    if( status != PSA_SUCCESS )
+        goto exit;
+
+exit:
+    if( status == PSA_SUCCESS )
+        status = mbedtls_psa_hash_abort( &operation );
+    else
+        mbedtls_psa_hash_abort( &operation );
+    return( status );
+}
+
+psa_status_t mbedtls_psa_hash_setup(
+    mbedtls_psa_hash_operation_t *operation,
+    psa_algorithm_t alg )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    /* A context must be freshly initialized before it can be set up. */
+    if( operation->alg != 0 )
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+    switch( alg )
+    {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
+        case PSA_ALG_MD2:
+            mbedtls_md2_init( &operation->ctx.md2 );
+            ret = mbedtls_md2_starts_ret( &operation->ctx.md2 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
+        case PSA_ALG_MD4:
+            mbedtls_md4_init( &operation->ctx.md4 );
+            ret = mbedtls_md4_starts_ret( &operation->ctx.md4 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
+        case PSA_ALG_MD5:
+            mbedtls_md5_init( &operation->ctx.md5 );
+            ret = mbedtls_md5_starts_ret( &operation->ctx.md5 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
+        case PSA_ALG_RIPEMD160:
+            mbedtls_ripemd160_init( &operation->ctx.ripemd160 );
+            ret = mbedtls_ripemd160_starts_ret( &operation->ctx.ripemd160 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
+        case PSA_ALG_SHA_1:
+            mbedtls_sha1_init( &operation->ctx.sha1 );
+            ret = mbedtls_sha1_starts_ret( &operation->ctx.sha1 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
+        case PSA_ALG_SHA_224:
+            mbedtls_sha256_init( &operation->ctx.sha256 );
+            ret = mbedtls_sha256_starts_ret( &operation->ctx.sha256, 1 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
+        case PSA_ALG_SHA_256:
+            mbedtls_sha256_init( &operation->ctx.sha256 );
+            ret = mbedtls_sha256_starts_ret( &operation->ctx.sha256, 0 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
+        case PSA_ALG_SHA_384:
+            mbedtls_sha512_init( &operation->ctx.sha512 );
+            ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 1 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
+        case PSA_ALG_SHA_512:
+            mbedtls_sha512_init( &operation->ctx.sha512 );
+            ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 0 );
+            break;
+#endif
+        default:
+            return( PSA_ALG_IS_HASH( alg ) ?
+                    PSA_ERROR_NOT_SUPPORTED :
+                    PSA_ERROR_INVALID_ARGUMENT );
+    }
+    if( ret == 0 )
+        operation->alg = alg;
+    else
+        mbedtls_psa_hash_abort( operation );
+    return( mbedtls_to_psa_error( ret ) );
+}
+
+psa_status_t mbedtls_psa_hash_clone(
+    const mbedtls_psa_hash_operation_t *source_operation,
+    mbedtls_psa_hash_operation_t *target_operation )
+{
+    switch( source_operation->alg )
+    {
+        case 0:
+            return( PSA_ERROR_BAD_STATE );
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
+        case PSA_ALG_MD2:
+            mbedtls_md2_clone( &target_operation->ctx.md2,
+                               &source_operation->ctx.md2 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
+        case PSA_ALG_MD4:
+            mbedtls_md4_clone( &target_operation->ctx.md4,
+                               &source_operation->ctx.md4 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
+        case PSA_ALG_MD5:
+            mbedtls_md5_clone( &target_operation->ctx.md5,
+                               &source_operation->ctx.md5 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
+        case PSA_ALG_RIPEMD160:
+            mbedtls_ripemd160_clone( &target_operation->ctx.ripemd160,
+                                     &source_operation->ctx.ripemd160 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
+        case PSA_ALG_SHA_1:
+            mbedtls_sha1_clone( &target_operation->ctx.sha1,
+                                &source_operation->ctx.sha1 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
+        case PSA_ALG_SHA_224:
+            mbedtls_sha256_clone( &target_operation->ctx.sha256,
+                                  &source_operation->ctx.sha256 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
+        case PSA_ALG_SHA_256:
+            mbedtls_sha256_clone( &target_operation->ctx.sha256,
+                                  &source_operation->ctx.sha256 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
+        case PSA_ALG_SHA_384:
+            mbedtls_sha512_clone( &target_operation->ctx.sha512,
+                                  &source_operation->ctx.sha512 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
+        case PSA_ALG_SHA_512:
+            mbedtls_sha512_clone( &target_operation->ctx.sha512,
+                                  &source_operation->ctx.sha512 );
+            break;
+#endif
+        default:
+            return( PSA_ERROR_NOT_SUPPORTED );
+    }
+
+    target_operation->alg = source_operation->alg;
+    return( PSA_SUCCESS );
+}
+
+psa_status_t mbedtls_psa_hash_update(
+    mbedtls_psa_hash_operation_t *operation,
+    const uint8_t *input,
+    size_t input_length )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    /* Don't require hash implementations to behave correctly on a
+     * zero-length input, which may have an invalid pointer. */
+    if( input_length == 0 )
+        return( PSA_SUCCESS );
+
+    switch( operation->alg )
+    {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
+        case PSA_ALG_MD2:
+            ret = mbedtls_md2_update_ret( &operation->ctx.md2,
+                                          input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
+        case PSA_ALG_MD4:
+            ret = mbedtls_md4_update_ret( &operation->ctx.md4,
+                                          input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
+        case PSA_ALG_MD5:
+            ret = mbedtls_md5_update_ret( &operation->ctx.md5,
+                                          input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
+        case PSA_ALG_RIPEMD160:
+            ret = mbedtls_ripemd160_update_ret( &operation->ctx.ripemd160,
+                                                input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
+        case PSA_ALG_SHA_1:
+            ret = mbedtls_sha1_update_ret( &operation->ctx.sha1,
+                                           input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
+        case PSA_ALG_SHA_224:
+            ret = mbedtls_sha256_update_ret( &operation->ctx.sha256,
+                                             input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
+        case PSA_ALG_SHA_256:
+            ret = mbedtls_sha256_update_ret( &operation->ctx.sha256,
+                                             input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
+        case PSA_ALG_SHA_384:
+            ret = mbedtls_sha512_update_ret( &operation->ctx.sha512,
+                                             input, input_length );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
+        case PSA_ALG_SHA_512:
+            ret = mbedtls_sha512_update_ret( &operation->ctx.sha512,
+                                             input, input_length );
+            break;
+#endif
+        default:
+            (void)input;
+            return( PSA_ERROR_BAD_STATE );
+    }
+
+    if( ret != 0 )
+        mbedtls_psa_hash_abort( operation );
+    return( mbedtls_to_psa_error( ret ) );
+}
+
+psa_status_t mbedtls_psa_hash_finish(
+    mbedtls_psa_hash_operation_t *operation,
+    uint8_t *hash,
+    size_t hash_size,
+    size_t *hash_length )
+{
+    psa_status_t status;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t actual_hash_length = PSA_HASH_LENGTH( operation->alg );
+
+    /* Fill the output buffer with something that isn't a valid hash
+     * (barring an attack on the hash and deliberately-crafted input),
+     * in case the caller doesn't check the return status properly. */
+    *hash_length = hash_size;
+    /* If hash_size is 0 then hash may be NULL and then the
+     * call to memset would have undefined behavior. */
+    if( hash_size != 0 )
+        memset( hash, '!', hash_size );
+
+    if( hash_size < actual_hash_length )
+    {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    switch( operation->alg )
+    {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
+        case PSA_ALG_MD2:
+            ret = mbedtls_md2_finish_ret( &operation->ctx.md2, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
+        case PSA_ALG_MD4:
+            ret = mbedtls_md4_finish_ret( &operation->ctx.md4, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
+        case PSA_ALG_MD5:
+            ret = mbedtls_md5_finish_ret( &operation->ctx.md5, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
+        case PSA_ALG_RIPEMD160:
+            ret = mbedtls_ripemd160_finish_ret( &operation->ctx.ripemd160, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
+        case PSA_ALG_SHA_1:
+            ret = mbedtls_sha1_finish_ret( &operation->ctx.sha1, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
+        case PSA_ALG_SHA_224:
+            ret = mbedtls_sha256_finish_ret( &operation->ctx.sha256, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
+        case PSA_ALG_SHA_256:
+            ret = mbedtls_sha256_finish_ret( &operation->ctx.sha256, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
+        case PSA_ALG_SHA_384:
+            ret = mbedtls_sha512_finish_ret( &operation->ctx.sha512, hash );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
+        case PSA_ALG_SHA_512:
+            ret = mbedtls_sha512_finish_ret( &operation->ctx.sha512, hash );
+            break;
+#endif
+        default:
+            return( PSA_ERROR_BAD_STATE );
+    }
+    status = mbedtls_to_psa_error( ret );
+
+exit:
+    if( status == PSA_SUCCESS )
+    {
+        *hash_length = actual_hash_length;
+        return( mbedtls_psa_hash_abort( operation ) );
+    }
+    else
+    {
+        mbedtls_psa_hash_abort( operation );
+        return( status );
+    }
+}
+
+psa_status_t mbedtls_psa_hash_abort(
+    mbedtls_psa_hash_operation_t *operation )
+{
+    switch( operation->alg )
+    {
+        case 0:
+            /* The object has (apparently) been initialized but it is not
+             * in use. It's ok to call abort on such an object, and there's
+             * nothing to do. */
+            break;
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
+        case PSA_ALG_MD2:
+            mbedtls_md2_free( &operation->ctx.md2 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
+        case PSA_ALG_MD4:
+            mbedtls_md4_free( &operation->ctx.md4 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
+        case PSA_ALG_MD5:
+            mbedtls_md5_free( &operation->ctx.md5 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
+        case PSA_ALG_RIPEMD160:
+            mbedtls_ripemd160_free( &operation->ctx.ripemd160 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
+        case PSA_ALG_SHA_1:
+            mbedtls_sha1_free( &operation->ctx.sha1 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
+        case PSA_ALG_SHA_224:
+            mbedtls_sha256_free( &operation->ctx.sha256 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
+        case PSA_ALG_SHA_256:
+            mbedtls_sha256_free( &operation->ctx.sha256 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
+        case PSA_ALG_SHA_384:
+            mbedtls_sha512_free( &operation->ctx.sha512 );
+            break;
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
+        case PSA_ALG_SHA_512:
+            mbedtls_sha512_free( &operation->ctx.sha512 );
+            break;
+#endif
+        default:
+            return( PSA_ERROR_BAD_STATE );
+    }
+    operation->alg = 0;
+    return( PSA_SUCCESS );
+}
+
+#endif /* MBEDTLS_PSA_CRYPTO_C */