diff --git a/contrib/passwordcheck/passwordcheck.c b/contrib/passwordcheck/passwordcheck.c
index 1da323c0aa..074836336d 100644
--- a/contrib/passwordcheck/passwordcheck.c
+++ b/contrib/passwordcheck/passwordcheck.c
@@ -74,7 +74,7 @@ check_password(const char *username,
 		 *
 		 * We only check for username = password.
 		 */
-		char	   *logdetail;
+		const char *logdetail = NULL;
 
 		if (plain_crypt_verify(username, shadow_pass, username, &logdetail) == STATUS_OK)
 			ereport(ERROR,
diff --git a/contrib/uuid-ossp/uuid-ossp.c b/contrib/uuid-ossp/uuid-ossp.c
index 4859bd1933..7c0fb812fd 100644
--- a/contrib/uuid-ossp/uuid-ossp.c
+++ b/contrib/uuid-ossp/uuid-ossp.c
@@ -319,14 +319,17 @@ uuid_generate_internal(int v, unsigned char *ns, const char *ptr, int len)
 					pg_cryptohash_ctx *ctx = pg_cryptohash_create(PG_MD5);
 
 					if (pg_cryptohash_init(ctx) < 0)
-						elog(ERROR, "could not initialize %s context", "MD5");
+						elog(ERROR, "could not initialize %s context: %s", "MD5",
+							 pg_cryptohash_error(ctx));
 					if (pg_cryptohash_update(ctx, ns, sizeof(uu)) < 0 ||
 						pg_cryptohash_update(ctx, (unsigned char *) ptr, len) < 0)
-						elog(ERROR, "could not update %s context", "MD5");
+						elog(ERROR, "could not update %s context: %s", "MD5",
+							 pg_cryptohash_error(ctx));
 					/* we assume sizeof MD5 result is 16, same as UUID size */
 					if (pg_cryptohash_final(ctx, (unsigned char *) &uu,
 											sizeof(uu)) < 0)
-						elog(ERROR, "could not finalize %s context", "MD5");
+						elog(ERROR, "could not finalize %s context: %s", "MD5",
+							 pg_cryptohash_error(ctx));
 					pg_cryptohash_free(ctx);
 				}
 				else
@@ -335,12 +338,15 @@ uuid_generate_internal(int v, unsigned char *ns, const char *ptr, int len)
 					unsigned char sha1result[SHA1_DIGEST_LENGTH];
 
 					if (pg_cryptohash_init(ctx) < 0)
-						elog(ERROR, "could not initialize %s context", "SHA1");
+						elog(ERROR, "could not initialize %s context: %s", "SHA1",
+							 pg_cryptohash_error(ctx));
 					if (pg_cryptohash_update(ctx, ns, sizeof(uu)) < 0 ||
 						pg_cryptohash_update(ctx, (unsigned char *) ptr, len) < 0)
-						elog(ERROR, "could not update %s context", "SHA1");
+						elog(ERROR, "could not update %s context: %s", "SHA1",
+							 pg_cryptohash_error(ctx));
 					if (pg_cryptohash_final(ctx, sha1result, sizeof(sha1result)) < 0)
-						elog(ERROR, "could not finalize %s context", "SHA1");
+						elog(ERROR, "could not finalize %s context: %s", "SHA1",
+							 pg_cryptohash_error(ctx));
 					pg_cryptohash_free(ctx);
 
 					memcpy(&uu, sha1result, sizeof(uu));
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index c79c8d247f..3b512a84b3 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -355,7 +355,7 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
 	if (password)
 	{
 		char	   *shadow_pass;
-		char	   *logdetail;
+		const char *logdetail = NULL;
 
 		/*
 		 * Don't allow an empty password. Libpq treats an empty password the
@@ -775,7 +775,7 @@ AlterRole(ParseState *pstate, AlterRoleStmt *stmt)
 	if (password)
 	{
 		char	   *shadow_pass;
-		char	   *logdetail;
+		const char *logdetail = NULL;
 
 		/* Like in CREATE USER, don't allow an empty password. */
 		if (password[0] == '\0' ||
diff --git a/src/backend/libpq/auth-sasl.c b/src/backend/libpq/auth-sasl.c
index 6cc776edeb..a1d7dbb6d5 100644
--- a/src/backend/libpq/auth-sasl.c
+++ b/src/backend/libpq/auth-sasl.c
@@ -50,7 +50,7 @@
  */
 int
 CheckSASLAuth(const pg_be_sasl_mech *mech, Port *port, char *shadow_pass,
-			  char **logdetail)
+			  const char **logdetail)
 {
 	StringInfoData sasl_mechs;
 	int			mtype;
diff --git a/src/backend/libpq/auth-scram.c b/src/backend/libpq/auth-scram.c
index fdfc3d5067..7c9dee70ce 100644
--- a/src/backend/libpq/auth-scram.c
+++ b/src/backend/libpq/auth-scram.c
@@ -111,7 +111,8 @@ static void scram_get_mechanisms(Port *port, StringInfo buf);
 static void *scram_init(Port *port, const char *selected_mech,
 						const char *shadow_pass);
 static int	scram_exchange(void *opaq, const char *input, int inputlen,
-						   char **output, int *outputlen, char **logdetail);
+						   char **output, int *outputlen,
+						   const char **logdetail);
 
 /* Mechanism declaration */
 const pg_be_sasl_mech pg_be_scram_mech = {
@@ -335,7 +336,7 @@ scram_init(Port *port, const char *selected_mech, const char *shadow_pass)
  */
 static int
 scram_exchange(void *opaq, const char *input, int inputlen,
-			   char **output, int *outputlen, char **logdetail)
+			   char **output, int *outputlen, const char **logdetail)
 {
 	scram_state *state = (scram_state *) opaq;
 	int			result;
diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index b0d6988aff..9a266beb5d 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -45,7 +45,7 @@
  * Global authentication functions
  *----------------------------------------------------------------
  */
-static void auth_failed(Port *port, int status, char *logdetail);
+static void auth_failed(Port *port, int status, const char *logdetail);
 static char *recv_password_packet(Port *port);
 static void set_authn_id(Port *port, const char *id);
 
@@ -54,10 +54,11 @@ static void set_authn_id(Port *port, const char *id);
  * Password-based authentication methods (password, md5, and scram-sha-256)
  *----------------------------------------------------------------
  */
-static int	CheckPasswordAuth(Port *port, char **logdetail);
-static int	CheckPWChallengeAuth(Port *port, char **logdetail);
+static int	CheckPasswordAuth(Port *port, const char **logdetail);
+static int	CheckPWChallengeAuth(Port *port, const char **logdetail);
 
-static int	CheckMD5Auth(Port *port, char *shadow_pass, char **logdetail);
+static int	CheckMD5Auth(Port *port, char *shadow_pass,
+						 const char **logdetail);
 
 
 /*----------------------------------------------------------------
@@ -247,7 +248,7 @@ ClientAuthentication_hook_type ClientAuthentication_hook = NULL;
  * particular, if logdetail isn't NULL, we send that string to the log.
  */
 static void
-auth_failed(Port *port, int status, char *logdetail)
+auth_failed(Port *port, int status, const char *logdetail)
 {
 	const char *errstr;
 	char	   *cdetail;
@@ -383,7 +384,7 @@ void
 ClientAuthentication(Port *port)
 {
 	int			status = STATUS_ERROR;
-	char	   *logdetail = NULL;
+	const char *logdetail = NULL;
 
 	/*
 	 * Get the authentication method to use for this frontend/database
@@ -769,7 +770,7 @@ recv_password_packet(Port *port)
  * Plaintext password authentication.
  */
 static int
-CheckPasswordAuth(Port *port, char **logdetail)
+CheckPasswordAuth(Port *port, const char **logdetail)
 {
 	char	   *passwd;
 	int			result;
@@ -804,7 +805,7 @@ CheckPasswordAuth(Port *port, char **logdetail)
  * MD5 and SCRAM authentication.
  */
 static int
-CheckPWChallengeAuth(Port *port, char **logdetail)
+CheckPWChallengeAuth(Port *port, const char **logdetail)
 {
 	int			auth_result;
 	char	   *shadow_pass;
@@ -866,7 +867,7 @@ CheckPWChallengeAuth(Port *port, char **logdetail)
 }
 
 static int
-CheckMD5Auth(Port *port, char *shadow_pass, char **logdetail)
+CheckMD5Auth(Port *port, char *shadow_pass, const char **logdetail)
 {
 	char		md5Salt[4];		/* Password salt */
 	char	   *passwd;
@@ -3085,6 +3086,8 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
 	md5trailer = packet->vector;
 	for (i = 0; i < encryptedpasswordlen; i += RADIUS_VECTOR_LENGTH)
 	{
+		const char *errstr = NULL;
+
 		memcpy(cryptvector + strlen(secret), md5trailer, RADIUS_VECTOR_LENGTH);
 
 		/*
@@ -3093,10 +3096,12 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
 		 */
 		md5trailer = encryptedpassword + i;
 
-		if (!pg_md5_binary(cryptvector, strlen(secret) + RADIUS_VECTOR_LENGTH, encryptedpassword + i))
+		if (!pg_md5_binary(cryptvector, strlen(secret) + RADIUS_VECTOR_LENGTH,
+						   encryptedpassword + i, &errstr))
 		{
 			ereport(LOG,
-					(errmsg("could not perform MD5 encryption of password")));
+					(errmsg("could not perform MD5 encryption of password: %s",
+							errstr)));
 			pfree(cryptvector);
 			pg_freeaddrinfo_all(hint.ai_family, serveraddrs);
 			return STATUS_ERROR;
@@ -3181,6 +3186,7 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
 		struct timeval timeout;
 		struct timeval now;
 		int64		timeoutval;
+		const char *errstr = NULL;
 
 		gettimeofday(&now, NULL);
 		timeoutval = (endtime.tv_sec * 1000000 + endtime.tv_usec) - (now.tv_sec * 1000000 + now.tv_usec);
@@ -3299,10 +3305,11 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
 
 		if (!pg_md5_binary(cryptvector,
 						   packetlength + strlen(secret),
-						   encryptedpassword))
+						   encryptedpassword, &errstr))
 		{
 			ereport(LOG,
-					(errmsg("could not perform MD5 encryption of received packet")));
+					(errmsg("could not perform MD5 encryption of received packet: %s",
+							errstr)));
 			pfree(cryptvector);
 			continue;
 		}
diff --git a/src/backend/libpq/crypt.c b/src/backend/libpq/crypt.c
index 7ebcdd7123..1ff8b0507d 100644
--- a/src/backend/libpq/crypt.c
+++ b/src/backend/libpq/crypt.c
@@ -34,7 +34,7 @@
  * sent to the client, to avoid giving away user information!
  */
 char *
-get_role_password(const char *role, char **logdetail)
+get_role_password(const char *role, const char **logdetail)
 {
 	TimestampTz vuntil = 0;
 	HeapTuple	roleTup;
@@ -116,6 +116,7 @@ encrypt_password(PasswordType target_type, const char *role,
 {
 	PasswordType guessed_type = get_password_type(password);
 	char	   *encrypted_password;
+	const char *errstr = NULL;
 
 	if (guessed_type != PASSWORD_TYPE_PLAINTEXT)
 	{
@@ -132,8 +133,8 @@ encrypt_password(PasswordType target_type, const char *role,
 			encrypted_password = palloc(MD5_PASSWD_LEN + 1);
 
 			if (!pg_md5_encrypt(password, role, strlen(role),
-								encrypted_password))
-				elog(ERROR, "password encryption failed");
+								encrypted_password, &errstr))
+				elog(ERROR, "password encryption failed: %s", errstr);
 			return encrypted_password;
 
 		case PASSWORD_TYPE_SCRAM_SHA_256:
@@ -159,17 +160,18 @@ encrypt_password(PasswordType target_type, const char *role,
  * 'client_pass' is the response given by the remote user to the MD5 challenge.
  * 'md5_salt' is the salt used in the MD5 authentication challenge.
  *
- * In the error case, optionally store a palloc'd string at *logdetail
- * that will be sent to the postmaster log (but not the client).
+ * In the error case, save a string at *logdetail that will be sent to the
+ * postmaster log (but not the client).
  */
 int
 md5_crypt_verify(const char *role, const char *shadow_pass,
 				 const char *client_pass,
 				 const char *md5_salt, int md5_salt_len,
-				 char **logdetail)
+				 const char **logdetail)
 {
 	int			retval;
 	char		crypt_pwd[MD5_PASSWD_LEN + 1];
+	const char *errstr = NULL;
 
 	Assert(md5_salt_len > 0);
 
@@ -183,16 +185,13 @@ md5_crypt_verify(const char *role, const char *shadow_pass,
 
 	/*
 	 * Compute the correct answer for the MD5 challenge.
-	 *
-	 * We do not bother setting logdetail for any pg_md5_encrypt failure
-	 * below: the only possible error is out-of-memory, which is unlikely, and
-	 * if it did happen adding a psprintf call would only make things worse.
 	 */
 	/* stored password already encrypted, only do salt */
 	if (!pg_md5_encrypt(shadow_pass + strlen("md5"),
 						md5_salt, md5_salt_len,
-						crypt_pwd))
+						crypt_pwd, &errstr))
 	{
+		*logdetail = errstr;
 		return STATUS_ERROR;
 	}
 
@@ -215,15 +214,16 @@ md5_crypt_verify(const char *role, const char *shadow_pass,
  * pg_authid.rolpassword.
  * 'client_pass' is the password given by the remote user.
  *
- * In the error case, optionally store a palloc'd string at *logdetail
- * that will be sent to the postmaster log (but not the client).
+ * In the error case, store a string at *logdetail that will be sent to the
+ * postmaster log (but not the client).
  */
 int
 plain_crypt_verify(const char *role, const char *shadow_pass,
 				   const char *client_pass,
-				   char **logdetail)
+				   const char **logdetail)
 {
 	char		crypt_client_pass[MD5_PASSWD_LEN + 1];
+	const char *errstr = NULL;
 
 	/*
 	 * Client sent password in plaintext.  If we have an MD5 hash stored, hash
@@ -251,14 +251,10 @@ plain_crypt_verify(const char *role, const char *shadow_pass,
 			if (!pg_md5_encrypt(client_pass,
 								role,
 								strlen(role),
-								crypt_client_pass))
+								crypt_client_pass,
+								&errstr))
 			{
-				/*
-				 * We do not bother setting logdetail for pg_md5_encrypt
-				 * failure: the only possible error is out-of-memory, which is
-				 * unlikely, and if it did happen adding a psprintf call would
-				 * only make things worse.
-				 */
+				*logdetail = errstr;
 				return STATUS_ERROR;
 			}
 			if (strcmp(crypt_client_pass, shadow_pass) == 0)
diff --git a/src/backend/replication/backup_manifest.c b/src/backend/replication/backup_manifest.c
index 1678b89266..7e22f9e48c 100644
--- a/src/backend/replication/backup_manifest.c
+++ b/src/backend/replication/backup_manifest.c
@@ -68,7 +68,8 @@ InitializeBackupManifest(backup_manifest_info *manifest,
 		manifest->buffile = BufFileCreateTemp(false);
 		manifest->manifest_ctx = pg_cryptohash_create(PG_SHA256);
 		if (pg_cryptohash_init(manifest->manifest_ctx) < 0)
-			elog(ERROR, "failed to initialize checksum of backup manifest");
+			elog(ERROR, "failed to initialize checksum of backup manifest: %s",
+				 pg_cryptohash_error(manifest->manifest_ctx));
 	}
 
 	manifest->manifest_size = UINT64CONST(0);
@@ -311,7 +312,7 @@ AddWALInfoToBackupManifest(backup_manifest_info *manifest, XLogRecPtr startptr,
  * Finalize the backup manifest, and send it to the client.
  */
 void
-SendBackupManifest(backup_manifest_info *manifest, bbsink *sink)
+SendBackupManifest(backup_manifest_info *manifest, bbsink * sink)
 {
 	uint8		checksumbuf[PG_SHA256_DIGEST_LENGTH];
 	char		checksumstringbuf[PG_SHA256_DIGEST_STRING_LENGTH];
@@ -334,7 +335,8 @@ SendBackupManifest(backup_manifest_info *manifest, bbsink *sink)
 	manifest->still_checksumming = false;
 	if (pg_cryptohash_final(manifest->manifest_ctx, checksumbuf,
 							sizeof(checksumbuf)) < 0)
-		elog(ERROR, "failed to finalize checksum of backup manifest");
+		elog(ERROR, "failed to finalize checksum of backup manifest: %s",
+			 pg_cryptohash_error(manifest->manifest_ctx));
 	AppendStringToManifest(manifest, "\"Manifest-Checksum\": \"");
 
 	hex_encode((char *) checksumbuf, sizeof checksumbuf, checksumstringbuf);
@@ -391,7 +393,8 @@ AppendStringToManifest(backup_manifest_info *manifest, char *s)
 	if (manifest->still_checksumming)
 	{
 		if (pg_cryptohash_update(manifest->manifest_ctx, (uint8 *) s, len) < 0)
-			elog(ERROR, "failed to update checksum of backup manifest");
+			elog(ERROR, "failed to update checksum of backup manifest: %s",
+				 pg_cryptohash_error(manifest->manifest_ctx));
 	}
 	BufFileWrite(manifest->buffile, s, len);
 	manifest->manifest_size += len;
diff --git a/src/backend/utils/adt/cryptohashfuncs.c b/src/backend/utils/adt/cryptohashfuncs.c
index 7e43c0e01d..03d84ea217 100644
--- a/src/backend/utils/adt/cryptohashfuncs.c
+++ b/src/backend/utils/adt/cryptohashfuncs.c
@@ -35,15 +35,17 @@ md5_text(PG_FUNCTION_ARGS)
 	text	   *in_text = PG_GETARG_TEXT_PP(0);
 	size_t		len;
 	char		hexsum[MD5_HASH_LEN + 1];
+	const char *errstr = NULL;
 
 	/* Calculate the length of the buffer using varlena metadata */
 	len = VARSIZE_ANY_EXHDR(in_text);
 
 	/* get the hash result */
-	if (pg_md5_hash(VARDATA_ANY(in_text), len, hexsum) == false)
+	if (pg_md5_hash(VARDATA_ANY(in_text), len, hexsum, &errstr) == false)
 		ereport(ERROR,
-				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory")));
+				(errcode(ERRCODE_INTERNAL_ERROR),
+				 errmsg("could not compute %s hash: %s", "MD5",
+						errstr)));
 
 	/* convert to text and return it */
 	PG_RETURN_TEXT_P(cstring_to_text(hexsum));
@@ -58,12 +60,14 @@ md5_bytea(PG_FUNCTION_ARGS)
 	bytea	   *in = PG_GETARG_BYTEA_PP(0);
 	size_t		len;
 	char		hexsum[MD5_HASH_LEN + 1];
+	const char *errstr = NULL;
 
 	len = VARSIZE_ANY_EXHDR(in);
-	if (pg_md5_hash(VARDATA_ANY(in), len, hexsum) == false)
+	if (pg_md5_hash(VARDATA_ANY(in), len, hexsum, &errstr) == false)
 		ereport(ERROR,
-				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory")));
+				(errcode(ERRCODE_INTERNAL_ERROR),
+				 errmsg("could not compute %s hash: %s", "MD5",
+						errstr)));
 
 	PG_RETURN_TEXT_P(cstring_to_text(hexsum));
 }
@@ -111,12 +115,15 @@ cryptohash_internal(pg_cryptohash_type type, bytea *input)
 
 	ctx = pg_cryptohash_create(type);
 	if (pg_cryptohash_init(ctx) < 0)
-		elog(ERROR, "could not initialize %s context", typestr);
+		elog(ERROR, "could not initialize %s context: %s", typestr,
+			 pg_cryptohash_error(ctx));
 	if (pg_cryptohash_update(ctx, data, len) < 0)
-		elog(ERROR, "could not update %s context", typestr);
+		elog(ERROR, "could not update %s context: %s", typestr,
+			 pg_cryptohash_error(ctx));
 	if (pg_cryptohash_final(ctx, (unsigned char *) VARDATA(result),
 							digest_len) < 0)
-		elog(ERROR, "could not finalize %s context", typestr);
+		elog(ERROR, "could not finalize %s context: %s", typestr,
+			 pg_cryptohash_error(ctx));
 	pg_cryptohash_free(ctx);
 
 	SET_VARSIZE(result, digest_len + VARHDRSZ);
diff --git a/src/common/cryptohash.c b/src/common/cryptohash.c
index b13815dd98..ddf35d28b2 100644
--- a/src/common/cryptohash.c
+++ b/src/common/cryptohash.c
@@ -40,10 +40,18 @@
 #define FREE(ptr) free(ptr)
 #endif
 
+/* Set of error states */
+typedef enum pg_cryptohash_errno
+{
+	PG_CRYPTOHASH_ERROR_NONE = 0,
+	PG_CRYPTOHASH_ERROR_DEST_LEN
+} pg_cryptohash_errno;
+
 /* Internal pg_cryptohash_ctx structure */
 struct pg_cryptohash_ctx
 {
 	pg_cryptohash_type type;
+	pg_cryptohash_errno error;
 
 	union
 	{
@@ -76,9 +84,10 @@ pg_cryptohash_create(pg_cryptohash_type type)
 	ctx = ALLOC(sizeof(pg_cryptohash_ctx));
 	if (ctx == NULL)
 		return NULL;
+
 	memset(ctx, 0, sizeof(pg_cryptohash_ctx));
 	ctx->type = type;
-
+	ctx->error = PG_CRYPTOHASH_ERROR_NONE;
 	return ctx;
 }
 
@@ -174,32 +183,50 @@ pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
 	{
 		case PG_MD5:
 			if (len < MD5_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			pg_md5_final(&ctx->data.md5, dest);
 			break;
 		case PG_SHA1:
 			if (len < SHA1_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			pg_sha1_final(&ctx->data.sha1, dest);
 			break;
 		case PG_SHA224:
 			if (len < PG_SHA224_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			pg_sha224_final(&ctx->data.sha224, dest);
 			break;
 		case PG_SHA256:
 			if (len < PG_SHA256_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			pg_sha256_final(&ctx->data.sha256, dest);
 			break;
 		case PG_SHA384:
 			if (len < PG_SHA384_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			pg_sha384_final(&ctx->data.sha384, dest);
 			break;
 		case PG_SHA512:
 			if (len < PG_SHA512_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			pg_sha512_final(&ctx->data.sha512, dest);
 			break;
 	}
@@ -221,3 +248,31 @@ pg_cryptohash_free(pg_cryptohash_ctx *ctx)
 	explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
 	FREE(ctx);
 }
+
+/*
+ * pg_cryptohash_error
+ *
+ * Returns a static string providing errors about an error that
+ * happened during a computation.
+ */
+const char *
+pg_cryptohash_error(pg_cryptohash_ctx *ctx)
+{
+	/*
+	 * This implementation would never fail because of an out-of-memory error,
+	 * except when creating the context.
+	 */
+	if (ctx == NULL)
+		return _("out of memory");
+
+	switch (ctx->error)
+	{
+		case PG_CRYPTOHASH_ERROR_NONE:
+			return _("success");
+		case PG_CRYPTOHASH_ERROR_DEST_LEN:
+			return _("destination buffer too small");
+	}
+
+	Assert(false);
+	return _("success");
+}
diff --git a/src/common/cryptohash_openssl.c b/src/common/cryptohash_openssl.c
index f7b390ed54..2e835b066b 100644
--- a/src/common/cryptohash_openssl.c
+++ b/src/common/cryptohash_openssl.c
@@ -21,6 +21,7 @@
 #include "postgres_fe.h"
 #endif
 
+#include <openssl/err.h>
 #include <openssl/evp.h>
 
 #include "common/cryptohash.h"
@@ -46,6 +47,14 @@
 #define FREE(ptr) free(ptr)
 #endif
 
+/* Set of error states */
+typedef enum pg_cryptohash_errno
+{
+	PG_CRYPTOHASH_ERROR_NONE = 0,
+	PG_CRYPTOHASH_ERROR_DEST_LEN,
+	PG_CRYPTOHASH_ERROR_OPENSSL
+} pg_cryptohash_errno;
+
 /*
  * Internal pg_cryptohash_ctx structure.
  *
@@ -55,6 +64,8 @@
 struct pg_cryptohash_ctx
 {
 	pg_cryptohash_type type;
+	pg_cryptohash_errno error;
+	const char *errreason;
 
 	EVP_MD_CTX *evpctx;
 
@@ -63,6 +74,19 @@ struct pg_cryptohash_ctx
 #endif
 };
 
+static const char *
+SSLerrmessage(unsigned long ecode)
+{
+	if (ecode == 0)
+		return NULL;
+
+	/*
+	 * This may return NULL, but we would fall back to a default error path if
+	 * that were the case.
+	 */
+	return ERR_reason_error_string(ecode);
+}
+
 /*
  * pg_cryptohash_create
  *
@@ -88,6 +112,8 @@ pg_cryptohash_create(pg_cryptohash_type type)
 		return NULL;
 	memset(ctx, 0, sizeof(pg_cryptohash_ctx));
 	ctx->type = type;
+	ctx->error = PG_CRYPTOHASH_ERROR_NONE;
+	ctx->errreason = NULL;
 
 	/*
 	 * Initialization takes care of assigning the correct type for OpenSSL.
@@ -153,7 +179,11 @@ pg_cryptohash_init(pg_cryptohash_ctx *ctx)
 
 	/* OpenSSL internals return 1 on success, 0 on failure */
 	if (status <= 0)
+	{
+		ctx->errreason = SSLerrmessage(ERR_get_error());
+		ctx->error = PG_CRYPTOHASH_ERROR_OPENSSL;
 		return -1;
+	}
 	return 0;
 }
 
@@ -174,7 +204,11 @@ pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len)
 
 	/* OpenSSL internals return 1 on success, 0 on failure */
 	if (status <= 0)
+	{
+		ctx->errreason = SSLerrmessage(ERR_get_error());
+		ctx->error = PG_CRYPTOHASH_ERROR_OPENSSL;
 		return -1;
+	}
 	return 0;
 }
 
@@ -195,27 +229,45 @@ pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
 	{
 		case PG_MD5:
 			if (len < MD5_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			break;
 		case PG_SHA1:
 			if (len < SHA1_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			break;
 		case PG_SHA224:
 			if (len < PG_SHA224_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			break;
 		case PG_SHA256:
 			if (len < PG_SHA256_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			break;
 		case PG_SHA384:
 			if (len < PG_SHA384_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			break;
 		case PG_SHA512:
 			if (len < PG_SHA512_DIGEST_LENGTH)
+			{
+				ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
 				return -1;
+			}
 			break;
 	}
 
@@ -223,7 +275,11 @@ pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
 
 	/* OpenSSL internals return 1 on success, 0 on failure */
 	if (status <= 0)
+	{
+		ctx->errreason = SSLerrmessage(ERR_get_error());
+		ctx->error = PG_CRYPTOHASH_ERROR_OPENSSL;
 		return -1;
+	}
 	return 0;
 }
 
@@ -248,3 +304,40 @@ pg_cryptohash_free(pg_cryptohash_ctx *ctx)
 	explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
 	FREE(ctx);
 }
+
+/*
+ * pg_cryptohash_error
+ *
+ * Returns a static string providing errors about an error that
+ * happened during a computation.
+ */
+const char *
+pg_cryptohash_error(pg_cryptohash_ctx *ctx)
+{
+	/*
+	 * This implementation would never fail because of an out-of-memory error,
+	 * except when creating the context.
+	 */
+	if (ctx == NULL)
+		return _("out of memory");
+
+	/*
+	 * If a reason is provided, rely on it, else fallback to any error code
+	 * set.
+	 */
+	if (ctx->errreason)
+		return ctx->errreason;
+
+	switch (ctx->error)
+	{
+		case PG_CRYPTOHASH_ERROR_NONE:
+			return _("success");
+		case PG_CRYPTOHASH_ERROR_DEST_LEN:
+			return _("destination buffer too small");
+		case PG_CRYPTOHASH_ERROR_OPENSSL:
+			return _("OpenSSL failure");
+	}
+
+	Assert(false);				/* cannot be reached */
+	return _("success");
+}
diff --git a/src/common/md5_common.c b/src/common/md5_common.c
index 65b0be4b66..edc935eeb8 100644
--- a/src/common/md5_common.c
+++ b/src/common/md5_common.c
@@ -67,7 +67,7 @@ bytesToHex(uint8 b[16], char *s)
  */
 
 bool
-pg_md5_hash(const void *buff, size_t len, char *hexsum)
+pg_md5_hash(const void *buff, size_t len, char *hexsum, const char **errstr)
 {
 	uint8		sum[MD5_DIGEST_LENGTH];
 	pg_cryptohash_ctx *ctx;
@@ -80,6 +80,7 @@ pg_md5_hash(const void *buff, size_t len, char *hexsum)
 		pg_cryptohash_update(ctx, buff, len) < 0 ||
 		pg_cryptohash_final(ctx, sum, sizeof(sum)) < 0)
 	{
+		*errstr = pg_cryptohash_error(ctx);
 		pg_cryptohash_free(ctx);
 		return false;
 	}
@@ -90,18 +91,23 @@ pg_md5_hash(const void *buff, size_t len, char *hexsum)
 }
 
 bool
-pg_md5_binary(const void *buff, size_t len, void *outbuf)
+pg_md5_binary(const void *buff, size_t len, void *outbuf, const char **errstr)
 {
 	pg_cryptohash_ctx *ctx;
 
+	*errstr = NULL;
 	ctx = pg_cryptohash_create(PG_MD5);
 	if (ctx == NULL)
+	{
+		*errstr = pg_cryptohash_error(NULL);	/* returns OOM */
 		return false;
+	}
 
 	if (pg_cryptohash_init(ctx) < 0 ||
 		pg_cryptohash_update(ctx, buff, len) < 0 ||
 		pg_cryptohash_final(ctx, outbuf, MD5_DIGEST_LENGTH) < 0)
 	{
+		*errstr = pg_cryptohash_error(ctx);
 		pg_cryptohash_free(ctx);
 		return false;
 	}
@@ -118,11 +124,12 @@ pg_md5_binary(const void *buff, size_t len, void *outbuf)
  * Output format is "md5" followed by a 32-hex-digit MD5 checksum.
  * Hence, the output buffer "buf" must be at least 36 bytes long.
  *
- * Returns true if okay, false on error (out of memory).
+ * Returns true if okay, false on error with *errstr providing some
+ * error context.
  */
 bool
 pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
-			   char *buf)
+			   char *buf, const char **errstr)
 {
 	size_t		passwd_len = strlen(passwd);
 
@@ -131,7 +138,10 @@ pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
 	bool		ret;
 
 	if (!crypt_buf)
+	{
+		*errstr = _("out of memory");
 		return false;
+	}
 
 	/*
 	 * Place salt at the end because it may be known by users trying to crack
@@ -141,7 +151,7 @@ pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
 	memcpy(crypt_buf + passwd_len, salt, salt_len);
 
 	strcpy(buf, "md5");
-	ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3);
+	ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3, errstr);
 
 	free(crypt_buf);
 
diff --git a/src/include/common/cryptohash.h b/src/include/common/cryptohash.h
index ea1300d5d4..8e339c83ad 100644
--- a/src/include/common/cryptohash.h
+++ b/src/include/common/cryptohash.h
@@ -34,5 +34,6 @@ extern int	pg_cryptohash_init(pg_cryptohash_ctx *ctx);
 extern int	pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len);
 extern int	pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len);
 extern void pg_cryptohash_free(pg_cryptohash_ctx *ctx);
+extern const char *pg_cryptohash_error(pg_cryptohash_ctx *ctx);
 
 #endif							/* PG_CRYPTOHASH_H */
diff --git a/src/include/common/md5.h b/src/include/common/md5.h
index bbd2ec0165..942ca4242c 100644
--- a/src/include/common/md5.h
+++ b/src/include/common/md5.h
@@ -26,9 +26,12 @@
 #define MD5_PASSWD_LEN	35
 
 /* Utilities common to all the MD5 implementations, as of md5_common.c */
-extern bool pg_md5_hash(const void *buff, size_t len, char *hexsum);
-extern bool pg_md5_binary(const void *buff, size_t len, void *outbuf);
+extern bool pg_md5_hash(const void *buff, size_t len, char *hexsum,
+						const char **errstr);
+extern bool pg_md5_binary(const void *buff, size_t len, void *outbuf,
+						  const char **errstr);
 extern bool pg_md5_encrypt(const char *passwd, const char *salt,
-						   size_t salt_len, char *buf);
+						   size_t salt_len, char *buf,
+						   const char **errstr);
 
 #endif							/* PG_MD5_H */
diff --git a/src/include/libpq/crypt.h b/src/include/libpq/crypt.h
index ee60772e94..3238cf66d3 100644
--- a/src/include/libpq/crypt.h
+++ b/src/include/libpq/crypt.h
@@ -35,12 +35,13 @@ extern PasswordType get_password_type(const char *shadow_pass);
 extern char *encrypt_password(PasswordType target_type, const char *role,
 							  const char *password);
 
-extern char *get_role_password(const char *role, char **logdetail);
+extern char *get_role_password(const char *role, const char **logdetail);
 
 extern int	md5_crypt_verify(const char *role, const char *shadow_pass,
 							 const char *client_pass, const char *md5_salt,
-							 int md5_salt_len, char **logdetail);
+							 int md5_salt_len, const char **logdetail);
 extern int	plain_crypt_verify(const char *role, const char *shadow_pass,
-							   const char *client_pass, char **logdetail);
+							   const char *client_pass,
+							   const char **logdetail);
 
 #endif
diff --git a/src/include/libpq/sasl.h b/src/include/libpq/sasl.h
index 7ba3f5f5bc..71cc0dc251 100644
--- a/src/include/libpq/sasl.h
+++ b/src/include/libpq/sasl.h
@@ -126,11 +126,11 @@ typedef struct pg_be_sasl_mech
 	int			(*exchange) (void *state,
 							 const char *input, int inputlen,
 							 char **output, int *outputlen,
-							 char **logdetail);
+							 const char **logdetail);
 } pg_be_sasl_mech;
 
 /* Common implementation for auth.c */
 extern int	CheckSASLAuth(const pg_be_sasl_mech *mech, Port *port,
-						  char *shadow_pass, char **logdetail);
+						  char *shadow_pass, const char **logdetail);
 
 #endif							/* PG_SASL_H */
diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
index 8d2e4e5db4..2e6b2e8f04 100644
--- a/src/interfaces/libpq/fe-auth.c
+++ b/src/interfaces/libpq/fe-auth.c
@@ -790,6 +790,7 @@ pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq)
 		case AUTH_REQ_MD5:
 			{
 				char	   *crypt_pwd2;
+				const char *errstr = NULL;
 
 				/* Allocate enough space for two MD5 hashes */
 				crypt_pwd = malloc(2 * (MD5_PASSWD_LEN + 1));
@@ -802,14 +803,21 @@ pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq)
 
 				crypt_pwd2 = crypt_pwd + MD5_PASSWD_LEN + 1;
 				if (!pg_md5_encrypt(password, conn->pguser,
-									strlen(conn->pguser), crypt_pwd2))
+									strlen(conn->pguser), crypt_pwd2,
+									&errstr))
 				{
+					appendPQExpBuffer(&conn->errorMessage,
+									  libpq_gettext("could not encrypt password: %s\n"),
+									  errstr);
 					free(crypt_pwd);
 					return STATUS_ERROR;
 				}
 				if (!pg_md5_encrypt(crypt_pwd2 + strlen("md5"), md5Salt,
-									4, crypt_pwd))
+									4, crypt_pwd, &errstr))
 				{
+					appendPQExpBuffer(&conn->errorMessage,
+									  libpq_gettext("could not encrypt password: %s\n"),
+									  errstr);
 					free(crypt_pwd);
 					return STATUS_ERROR;
 				}
@@ -1175,12 +1183,13 @@ char *
 PQencryptPassword(const char *passwd, const char *user)
 {
 	char	   *crypt_pwd;
+	const char *errstr = NULL;
 
 	crypt_pwd = malloc(MD5_PASSWD_LEN + 1);
 	if (!crypt_pwd)
 		return NULL;
 
-	if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd))
+	if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd, &errstr))
 	{
 		free(crypt_pwd);
 		return NULL;
@@ -1287,8 +1296,13 @@ PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user,
 		crypt_pwd = malloc(MD5_PASSWD_LEN + 1);
 		if (crypt_pwd)
 		{
-			if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd))
+			const char *errstr = NULL;
+
+			if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd, &errstr))
 			{
+				appendPQExpBuffer(&conn->errorMessage,
+								  libpq_gettext("could not encrypt password: %s\n"),
+								  errstr);
 				free(crypt_pwd);
 				crypt_pwd = NULL;
 			}
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f093605472..5015fa7db0 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3350,6 +3350,7 @@ pg_conv_map
 pg_crc32
 pg_crc32c
 pg_cryptohash_ctx
+pg_cryptohash_errno
 pg_cryptohash_type
 pg_ctype_cache
 pg_enc